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.
26 Allows deeply nested structures to be simplified when printing by
27 replacing deeply nested parts (beyond the max-depth) with ellipses.
28 The default max-depth is 20, but this can be set to unlimited to get
29 the old behavior back.
33 ** The gdb.Value type has a new method 'format_string' which returns a
34 string representing the value. The formatting is controlled by the
35 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
36 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
37 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
41 set may-call-functions [on|off]
42 show may-call-functions
43 This controls whether GDB will attempt to call functions in
44 the program, such as with expressions in the print command. It
45 defaults to on. Calling functions in the program being debugged
46 can have undesired side effects. It is now possible to forbid
47 such function calls. If function calls are forbidden, GDB will throw
48 an error when a command (such as print expression) calls a function
51 *** Changes in GDB 8.3
53 * GDB and GDBserver now support access to additional registers on
54 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
57 * GDB now has experimental support for the compilation and injection of
58 C++ source code into the inferior. This beta release does not include
59 support for several language features, such as templates, constructors,
62 This feature requires GCC 7.1 or higher built with libcp1.so
65 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
66 can be passed using the '[ADDRESS]:PORT' notation, or the regular
67 'ADDRESS:PORT' method.
69 * DWARF index cache: GDB can now automatically save indices of DWARF
70 symbols on disk to speed up further loading of the same binaries.
72 * Ada task switching is now supported on aarch64-elf targets when
73 debugging a program using the Ravenscar Profile. For more information,
74 see the "Tasking Support when using the Ravenscar Profile" section
75 in the GDB user manual.
77 * GDB in batch mode now exits with status 1 if the last command to be
80 * The RISC-V target now supports target descriptions.
82 * System call catchpoints now support system call aliases on FreeBSD.
83 When the ABI of a system call changes in FreeBSD, this is
84 implemented by leaving a compatibility system call using the old ABI
85 at the existing number and allocating a new system call number for
86 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
87 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
88 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
89 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
90 so that a system call catchpoint for the 'kevent' system call will
91 catch invocations of both the 'kevent' and 'freebsd11_kevent'
92 binaries. This ensures that 'kevent' system calls are caught for
93 binaries using either the old or new ABIs.
95 * Terminal styling is now available for the CLI and the TUI. GNU
96 Source Highlight can additionally be used to provide styling of
97 source code snippets. See the "set style" commands, below, for more
100 * Removed support for old demangling styles arm, edg, gnu, hp and
105 set debug compile-cplus-types
106 show debug compile-cplus-types
107 Control the display of debug output about type conversion in the
108 C++ compile feature. Commands have no effect while compiliong
113 Control whether debug output about files/functions skipping is
116 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
117 Apply a command to some frames.
118 FLAG arguments allow to control what output to produce and how to handle
119 errors raised when applying COMMAND to a frame.
122 Apply a command to all threads (ignoring errors and empty output).
123 Shortcut for 'thread apply all -s COMMAND'.
126 Apply a command to all frames (ignoring errors and empty output).
127 Shortcut for 'frame apply all -s COMMAND'.
130 Apply a command to all frames of all threads (ignoring errors and empty
132 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
134 maint set dwarf unwinders (on|off)
135 maint show dwarf unwinders
136 Control whether DWARF unwinders can be used.
139 Display a list of open files for a process.
143 Changes to the "frame", "select-frame", and "info frame" CLI commands.
144 These commands all now take a frame specification which
145 is either a frame level, or one of the keywords 'level', 'address',
146 'function', or 'view' followed by a parameter. Selecting a frame by
147 address, or viewing a frame outside the current backtrace now
148 requires the use of a keyword. Selecting a frame by level is
149 unchanged. The MI comment "-stack-select-frame" is unchanged.
151 target remote FILENAME
152 target extended-remote FILENAME
153 If FILENAME is a Unix domain socket, GDB will attempt to connect
154 to this socket instead of opening FILENAME as a character device.
156 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
157 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
158 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
159 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
160 These commands can now print only the searched entities
161 matching the provided regexp(s), giving a condition
162 on the entity names or entity types. The flag -q disables
163 printing headers or informations messages.
169 These commands now determine the syntax for the shown entities
170 according to the language chosen by `set language'. In particular,
171 `set language auto' means to automatically choose the language of
174 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
175 The 'thread apply' command accepts new FLAG arguments.
176 FLAG arguments allow to control what output to produce and how to handle
177 errors raised when applying COMMAND to a thread.
179 set tui tab-width NCHARS
180 show tui tab-width NCHARS
181 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
183 set style enabled [on|off]
185 Enable or disable terminal styling. Styling is enabled by default
186 on most hosts, but disabled by default when in batch mode.
188 set style sources [on|off]
190 Enable or disable source code styling. Source code styling is
191 enabled by default, but only takes effect if styling in general is
192 enabled, and if GDB was linked with GNU Source Highlight.
194 set style filename foreground COLOR
195 set style filename background COLOR
196 set style filename intensity VALUE
197 Control the styling of file names.
199 set style function foreground COLOR
200 set style function background COLOR
201 set style function intensity VALUE
202 Control the styling of function names.
204 set style variable foreground COLOR
205 set style variable background COLOR
206 set style variable intensity VALUE
207 Control the styling of variable names.
209 set style address foreground COLOR
210 set style address background COLOR
211 set style address intensity VALUE
212 Control the styling of addresses.
216 ** The default version of the MI interpreter is now 3 (-i=mi3).
218 ** The '-data-disassemble' MI command now accepts an '-a' option to
219 disassemble the whole function surrounding the given program
220 counter value or function name. Support for this feature can be
221 verified by using the "-list-features" command, which should
222 contain "data-disassemble-a-option".
224 ** Command responses and notifications that include a frame now include
225 the frame's architecture in a new "arch" attribute.
227 ** The output of information about multi-location breakpoints (which is
228 syntactically incorrect in MI 2) has changed in MI 3. This affects
229 the following commands and events:
233 - =breakpoint-created
234 - =breakpoint-modified
236 The -fix-multi-location-breakpoint-output command can be used to enable
237 this behavior with previous MI versions.
239 * New native configurations
241 GNU/Linux/RISC-V riscv*-*-linux*
242 FreeBSD/riscv riscv*-*-freebsd*
246 GNU/Linux/RISC-V riscv*-*-linux*
248 CSKY GNU/LINUX csky*-*-linux
249 FreeBSD/riscv riscv*-*-freebsd*
251 GNU/Linux/OpenRISC or1k*-*-linux*
255 GDB no longer supports native debugging on versions of MS-Windows
260 ** GDB no longer supports Python versions less than 2.6.
262 ** The gdb.Inferior type has a new 'progspace' property, which is the program
263 space associated to that inferior.
265 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
266 of objfiles associated to that program space.
268 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
269 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
272 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
273 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
274 correct and did not work properly.
276 ** The gdb.Value type has a new constructor, which is used to construct a
277 gdb.Value from a Python buffer object and a gdb.Type.
283 Enable or disable the undefined behavior sanitizer. This is
284 disabled by default, but passing --enable-ubsan=yes or
285 --enable-ubsan=auto to configure will enable it. Enabling this can
286 cause a performance penalty. The undefined behavior sanitizer was
287 first introduced in GCC 4.9.
289 *** Changes in GDB 8.2
291 * The 'set disassembler-options' command now supports specifying options
294 * The 'symbol-file' command now accepts an '-o' option to add a relative
295 offset to all sections.
297 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
298 a relative offset to all sections, but it allows to override the load
299 address of individual sections using '-s'.
301 * The 'add-symbol-file' command no longer requires the second argument
302 (address of the text section).
304 * The endianness used with the 'set endian auto' mode in the absence of
305 an executable selected for debugging is now the last endianness chosen
306 either by one of the 'set endian big' and 'set endian little' commands
307 or by inferring from the last executable used, rather than the startup
310 * The pager now allows a "c" response, meaning to disable the pager
311 for the rest of the current command.
313 * The commands 'info variables/functions/types' now show the source line
314 numbers of symbol definitions when available.
316 * 'info proc' now works on running processes on FreeBSD systems and core
317 files created on FreeBSD systems.
319 * C expressions can now use _Alignof, and C++ expressions can now use
322 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
323 the vector length while the process is running.
329 Control display of debugging info regarding the FreeBSD native target.
331 set|show varsize-limit
332 This new setting allows the user to control the maximum size of Ada
333 objects being printed when those objects have a variable type,
334 instead of that maximum size being hardcoded to 65536 bytes.
336 set|show record btrace cpu
337 Controls the processor to be used for enabling errata workarounds for
340 maint check libthread-db
341 Run integrity checks on the current inferior's thread debugging
344 maint set check-libthread-db (on|off)
345 maint show check-libthread-db
346 Control whether to run integrity checks on inferior specific thread
347 debugging libraries as they are loaded. The default is not to
352 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
354 ** The commands attached to a breakpoint can be set by assigning to
355 the breakpoint's "commands" field.
357 ** gdb.execute can now execute multi-line gdb commands.
359 ** The new functions gdb.convenience_variable and
360 gdb.set_convenience_variable can be used to get and set the value
361 of convenience variables.
363 ** A gdb.Parameter will no longer print the "set" help text on an
364 ordinary "set"; instead by default a "set" will be silent unless
365 the get_set_string method returns a non-empty string.
369 RiscV ELF riscv*-*-elf
371 * Removed targets and native configurations
373 m88k running OpenBSD m88*-*-openbsd*
374 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
375 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
376 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
378 * Aarch64/Linux hardware watchpoints improvements
380 Hardware watchpoints on unaligned addresses are now properly
381 supported when running Linux kernel 4.10 or higher: read and access
382 watchpoints are no longer spuriously missed, and all watchpoints
383 lengths between 1 and 8 bytes are supported. On older kernels,
384 watchpoints set on unaligned addresses are no longer missed, with
385 the tradeoff that there is a possibility of false hits being
390 --enable-codesign=CERT
391 This can be used to invoke "codesign -s CERT" after building gdb.
392 This option is useful on macOS, where code signing is required for
393 gdb to work properly.
395 --disable-gdbcli has been removed
396 This is now silently accepted, but does nothing.
398 *** Changes in GDB 8.1
400 * GDB now supports dynamically creating arbitrary register groups specified
401 in XML target descriptions. This allows for finer grain grouping of
402 registers on systems with a large amount of registers.
404 * The 'ptype' command now accepts a '/o' flag, which prints the
405 offsets and sizes of fields in a struct, like the pahole(1) tool.
407 * New "--readnever" command line option instructs GDB to not read each
408 symbol file's symbolic debug information. This makes startup faster
409 but at the expense of not being able to perform symbolic debugging.
410 This option is intended for use cases where symbolic debugging will
411 not be used, e.g., when you only need to dump the debuggee's core.
413 * GDB now uses the GNU MPFR library, if available, to emulate target
414 floating-point arithmetic during expression evaluation when the target
415 uses different floating-point formats than the host. At least version
416 3.1 of GNU MPFR is required.
418 * GDB now supports access to the guarded-storage-control registers and the
419 software-based guarded-storage broadcast control registers on IBM z14.
421 * On Unix systems, GDB now supports transmitting environment variables
422 that are to be set or unset to GDBserver. These variables will
423 affect the environment to be passed to the remote inferior.
425 To inform GDB of environment variables that are to be transmitted to
426 GDBserver, use the "set environment" command. Only user set
427 environment variables are sent to GDBserver.
429 To inform GDB of environment variables that are to be unset before
430 the remote inferior is started by the GDBserver, use the "unset
431 environment" command.
433 * Completion improvements
435 ** GDB can now complete function parameters in linespecs and
436 explicit locations without quoting. When setting breakpoints,
437 quoting around functions names to help with TAB-completion is
438 generally no longer necessary. For example, this now completes
441 (gdb) b function(in[TAB]
442 (gdb) b function(int)
444 Related, GDB is no longer confused with completing functions in
445 C++ anonymous namespaces:
448 (gdb) b (anonymous namespace)::[TAB][TAB]
449 (anonymous namespace)::a_function()
450 (anonymous namespace)::b_function()
452 ** GDB now has much improved linespec and explicit locations TAB
453 completion support, that better understands what you're
454 completing and offers better suggestions. For example, GDB no
455 longer offers data symbols as possible completions when you're
456 setting a breakpoint.
458 ** GDB now TAB-completes label symbol names.
460 ** The "complete" command now mimics TAB completion accurately.
462 * New command line options (gcore)
465 Dump all memory mappings.
467 * Breakpoints on C++ functions are now set on all scopes by default
469 By default, breakpoints on functions/methods are now interpreted as
470 specifying all functions with the given name ignoring missing
471 leading scopes (namespaces and classes).
473 For example, assuming a C++ program with symbols named:
478 both commands "break func()" and "break B::func()" set a breakpoint
481 You can use the new flag "-qualified" to override this. This makes
482 GDB interpret the specified function name as a complete
483 fully-qualified name instead. For example, using the same C++
484 program, the "break -q B::func" command sets a breakpoint on
485 "B::func", only. A parameter has been added to the Python
486 gdb.Breakpoint constructor to achieve the same result when creating
487 a breakpoint from Python.
489 * Breakpoints on functions marked with C++ ABI tags
491 GDB can now set breakpoints on functions marked with C++ ABI tags
492 (e.g., [abi:cxx11]). See here for a description of ABI tags:
493 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
495 Functions with a C++11 abi tag are demangled/displayed like this:
497 function[abi:cxx11](int)
500 You can now set a breakpoint on such functions simply as if they had
503 (gdb) b function(int)
505 Or if you need to disambiguate between tags, like:
507 (gdb) b function[abi:other_tag](int)
509 Tab completion was adjusted accordingly as well.
513 ** New events gdb.new_inferior, gdb.inferior_deleted, and
514 gdb.new_thread are emitted. See the manual for further
515 description of these.
517 ** A new function, "gdb.rbreak" has been added to the Python API.
518 This function allows the setting of a large number of breakpoints
519 via a regex pattern in Python. See the manual for further details.
521 ** Python breakpoints can now accept explicit locations. See the
522 manual for a further description of this feature.
525 * New features in the GDB remote stub, GDBserver
527 ** GDBserver is now able to start inferior processes with a
528 specified initial working directory.
530 The user can set the desired working directory to be used from
531 GDB using the new "set cwd" command.
533 ** New "--selftest" command line option runs some GDBserver self
534 tests. These self tests are disabled in releases.
536 ** On Unix systems, GDBserver now does globbing expansion and variable
537 substitution in inferior command line arguments.
539 This is done by starting inferiors using a shell, like GDB does.
540 See "set startup-with-shell" in the user manual for how to disable
541 this from GDB when using "target extended-remote". When using
542 "target remote", you can disable the startup with shell by using the
543 new "--no-startup-with-shell" GDBserver command line option.
545 ** On Unix systems, GDBserver now supports receiving environment
546 variables that are to be set or unset from GDB. These variables
547 will affect the environment to be passed to the inferior.
549 * When catching an Ada exception raised with a message, GDB now prints
550 the message in the catchpoint hit notification. In GDB/MI mode, that
551 information is provided as an extra field named "exception-message"
552 in the *stopped notification.
554 * Trait objects can now be inspected When debugging Rust code. This
555 requires compiler support which will appear in Rust 1.24.
559 QEnvironmentHexEncoded
560 Inform GDBserver of an environment variable that is to be passed to
561 the inferior when starting it.
564 Inform GDBserver of an environment variable that is to be unset
565 before starting the remote inferior.
568 Inform GDBserver that the environment should be reset (i.e.,
569 user-set environment variables should be unset).
572 Indicates whether the inferior must be started with a shell or not.
575 Tell GDBserver that the inferior to be started should use a specific
578 * The "maintenance print c-tdesc" command now takes an optional
579 argument which is the file name of XML target description.
581 * The "maintenance selftest" command now takes an optional argument to
582 filter the tests to be run.
584 * The "enable", and "disable" commands now accept a range of
585 breakpoint locations, e.g. "enable 1.3-5".
590 Set and show the current working directory for the inferior.
593 Set and show compilation command used for compiling and injecting code
594 with the 'compile' commands.
596 set debug separate-debug-file
597 show debug separate-debug-file
598 Control the display of debug output about separate debug file search.
600 set dump-excluded-mappings
601 show dump-excluded-mappings
602 Control whether mappings marked with the VM_DONTDUMP flag should be
603 dumped when generating a core file.
606 List the registered selftests.
609 Start the debugged program stopping at the first instruction.
612 Control display of debugging messages related to OpenRISC targets.
614 set|show print type nested-type-limit
615 Set and show the limit of nesting level for nested types that the
616 type printer will show.
618 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
621 * Safer/improved support for debugging with no debug info
623 GDB no longer assumes functions with no debug information return
626 This means that GDB now refuses to call such functions unless you
627 tell it the function's type, by either casting the call to the
628 declared return type, or by casting the function to a function
629 pointer of the right type, and calling that:
631 (gdb) p getenv ("PATH")
632 'getenv' has unknown return type; cast the call to its declared return type
633 (gdb) p (char *) getenv ("PATH")
634 $1 = 0x7fffffffe "/usr/local/bin:/"...
635 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
636 $2 = 0x7fffffffe "/usr/local/bin:/"...
638 Similarly, GDB no longer assumes that global variables with no debug
639 info have type 'int', and refuses to print the variable's value
640 unless you tell it the variable's type:
643 'var' has unknown type; cast it to its declared type
647 * New native configurations
649 FreeBSD/aarch64 aarch64*-*-freebsd*
650 FreeBSD/arm arm*-*-freebsd*
654 FreeBSD/aarch64 aarch64*-*-freebsd*
655 FreeBSD/arm arm*-*-freebsd*
656 OpenRISC ELF or1k*-*-elf
658 * Removed targets and native configurations
660 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
662 *** Changes in GDB 8.0
664 * GDB now supports access to the PKU register on GNU/Linux. The register is
665 added by the Memory Protection Keys for Userspace feature which will be
666 available in future Intel CPUs.
668 * GDB now supports C++11 rvalue references.
672 ** New functions to start, stop and access a running btrace recording.
673 ** Rvalue references are now supported in gdb.Type.
675 * GDB now supports recording and replaying rdrand and rdseed Intel 64
678 * Building GDB and GDBserver now requires a C++11 compiler.
680 For example, GCC 4.8 or later.
682 It is no longer possible to build GDB or GDBserver with a C
683 compiler. The --disable-build-with-cxx configure option has been
686 * Building GDB and GDBserver now requires GNU make >= 3.81.
688 It is no longer supported to build GDB or GDBserver with another
689 implementation of the make program or an earlier version of GNU make.
691 * Native debugging on MS-Windows supports command-line redirection
693 Command-line arguments used for starting programs on MS-Windows can
694 now include redirection symbols supported by native Windows shells,
695 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
696 as "run", "start", and "set args", as well as the corresponding MI
699 * Support for thread names on MS-Windows.
701 GDB now catches and handles the special exception that programs
702 running on MS-Windows use to assign names to threads in the
705 * Support for Java programs compiled with gcj has been removed.
707 * User commands now accept an unlimited number of arguments.
708 Previously, only up to 10 was accepted.
710 * The "eval" command now expands user-defined command arguments.
712 This makes it easier to process a variable number of arguments:
717 eval "print $arg%d", $i
722 * Target descriptions can now describe registers for sparc32 and sparc64.
724 * GDB now supports DWARF version 5 (debug information format).
725 Its .debug_names index is not yet supported.
727 * New native configurations
729 FreeBSD/mips mips*-*-freebsd
733 Synopsys ARC arc*-*-elf32
734 FreeBSD/mips mips*-*-freebsd
736 * Removed targets and native configurations
738 Alpha running FreeBSD alpha*-*-freebsd*
739 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
744 Erases all the flash memory regions reported by the target.
746 maint print arc arc-instruction address
747 Print internal disassembler information about instruction at a given address.
751 set disassembler-options
752 show disassembler-options
753 Controls the passing of target specific information to the disassembler.
754 If it is necessary to specify more than one disassembler option then
755 multiple options can be placed together into a comma separated list.
756 The default value is the empty string. Currently, the only supported
757 targets are ARM, PowerPC and S/390.
762 Erases all the flash memory regions reported by the target. This is
763 equivalent to the CLI command flash-erase.
765 -file-list-shared-libraries
766 List the shared libraries in the program. This is
767 equivalent to the CLI command "info shared".
770 Catchpoints stopping the program when Ada exceptions are
771 handled. This is equivalent to the CLI command "catch handlers".
773 *** Changes in GDB 7.12
775 * GDB and GDBserver now build with a C++ compiler by default.
777 The --enable-build-with-cxx configure option is now enabled by
778 default. One must now explicitly configure with
779 --disable-build-with-cxx in order to build with a C compiler. This
780 option will be removed in a future release.
782 * GDBserver now supports recording btrace without maintaining an active
785 * GDB now supports a negative repeat count in the 'x' command to examine
786 memory backward from the given address. For example:
789 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
790 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
791 (gdb) x/-5i 0x0000000000400580
792 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
793 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
794 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
795 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
796 0x40057b <main(int, char**)+25>:
797 callq 0x400536 <Func1(int, char const*)>
799 * Fortran: Support structures with fields of dynamic types and
800 arrays of dynamic types.
802 * The symbol dumping maintenance commands have new syntax.
803 maint print symbols [-pc address] [--] [filename]
804 maint print symbols [-objfile objfile] [-source source] [--] [filename]
805 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
806 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
807 maint print msymbols [-objfile objfile] [--] [filename]
809 * GDB now supports multibit bitfields and enums in target register
812 * New Python-based convenience function $_as_string(val), which returns
813 the textual representation of a value. This function is especially
814 useful to obtain the text label of an enum value.
816 * Intel MPX bound violation handling.
818 Segmentation faults caused by a Intel MPX boundary violation
819 now display the kind of violation (upper or lower), the memory
820 address accessed and the memory bounds, along with the usual
821 signal received and code location.
825 Program received signal SIGSEGV, Segmentation fault
826 Upper bound violation while accessing address 0x7fffffffc3b3
827 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
828 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
830 * Rust language support.
831 GDB now supports debugging programs written in the Rust programming
832 language. See https://www.rust-lang.org/ for more information about
835 * Support for running interpreters on specified input/output devices
837 GDB now supports a new mechanism that allows frontends to provide
838 fully featured GDB console views, as a better alternative to
839 building such views on top of the "-interpreter-exec console"
840 command. See the new "new-ui" command below. With that command,
841 frontends can now start GDB in the traditional command-line mode
842 running in an embedded terminal emulator widget, and create a
843 separate MI interpreter running on a specified i/o device. In this
844 way, GDB handles line editing, history, tab completion, etc. in the
845 console all by itself, and the GUI uses the separate MI interpreter
846 for its own control and synchronization, invisible to the command
849 * The "catch syscall" command catches groups of related syscalls.
851 The "catch syscall" command now supports catching a group of related
852 syscalls using the 'group:' or 'g:' prefix.
857 skip -gfile file-glob-pattern
858 skip -function function
859 skip -rfunction regular-expression
860 A generalized form of the skip command, with new support for
861 glob-style file names and regular expressions for function names.
862 Additionally, a file spec and a function spec may now be combined.
864 maint info line-table REGEXP
865 Display the contents of GDB's internal line table data struture.
868 Run any GDB unit tests that were compiled in.
871 Start a new user interface instance running INTERP as interpreter,
872 using the TTY file for input/output.
876 ** gdb.Breakpoint objects have a new attribute "pending", which
877 indicates whether the breakpoint is pending.
878 ** Three new breakpoint-related events have been added:
879 gdb.breakpoint_created, gdb.breakpoint_modified, and
880 gdb.breakpoint_deleted.
883 Signal ("set") the given MS-Windows event object. This is used in
884 conjunction with the Windows JIT debugging (AeDebug) support, where
885 the OS suspends a crashing process until a debugger can attach to
886 it. Resuming the crashing process, in order to debug it, is done by
889 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
890 was added in GDBserver, including JIT compiling fast tracepoint's
891 conditional expression bytecode into native code.
893 * Support for various remote target protocols and ROM monitors has
896 target m32rsdi Remote M32R debugging over SDI
897 target mips MIPS remote debugging protocol
898 target pmon PMON ROM monitor
899 target ddb NEC's DDB variant of PMON for Vr4300
900 target rockhopper NEC RockHopper variant of PMON
901 target lsi LSI variant of PMO
903 * Support for tracepoints and fast tracepoints on powerpc-linux,
904 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
905 including JIT compiling fast tracepoint's conditional expression
906 bytecode into native code.
908 * MI async record =record-started now includes the method and format used for
909 recording. For example:
911 =record-started,thread-group="i1",method="btrace",format="bts"
913 * MI async record =thread-selected now includes the frame field. For example:
915 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
919 Andes NDS32 nds32*-*-elf
921 *** Changes in GDB 7.11
923 * GDB now supports debugging kernel-based threads on FreeBSD.
925 * Per-inferior thread numbers
927 Thread numbers are now per inferior instead of global. If you're
928 debugging multiple inferiors, GDB displays thread IDs using a
929 qualified INF_NUM.THR_NUM form. For example:
933 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
934 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
935 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
936 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
938 As consequence, thread numbers as visible in the $_thread
939 convenience variable and in Python's InferiorThread.num attribute
940 are no longer unique between inferiors.
942 GDB now maintains a second thread ID per thread, referred to as the
943 global thread ID, which is the new equivalent of thread numbers in
944 previous releases. See also $_gthread below.
946 For backwards compatibility, MI's thread IDs always refer to global
949 * Commands that accept thread IDs now accept the qualified
950 INF_NUM.THR_NUM form as well. For example:
953 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
956 * In commands that accept a list of thread IDs, you can now refer to
957 all threads of an inferior using a star wildcard. GDB accepts
958 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
959 refer to all threads of the current inferior. For example, "info
962 * You can use "info threads -gid" to display the global thread ID of
965 * The new convenience variable $_gthread holds the global number of
968 * The new convenience variable $_inferior holds the number of the
971 * GDB now displays the ID and name of the thread that hit a breakpoint
972 or received a signal, if your program is multi-threaded. For
975 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
976 Thread 1 "main" received signal SIGINT, Interrupt.
978 * Record btrace now supports non-stop mode.
980 * Support for tracepoints on aarch64-linux was added in GDBserver.
982 * The 'record instruction-history' command now indicates speculative execution
983 when using the Intel Processor Trace recording format.
985 * GDB now allows users to specify explicit locations, bypassing
986 the linespec parser. This feature is also available to GDB/MI
989 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
990 GDB now is able to debug both AArch64 applications and ARM applications
993 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
994 including JIT compiling fast tracepoint's conditional expression bytecode
997 * GDB now supports displaced stepping on AArch64 GNU/Linux.
999 * "info threads", "info inferiors", "info display", "info checkpoints"
1000 and "maint info program-spaces" now list the corresponding items in
1001 ascending ID order, for consistency with all other "info" commands.
1003 * In Ada, the overloads selection menu has been enhanced to display the
1004 parameter types and the return types for the matching overloaded subprograms.
1008 maint set target-non-stop (on|off|auto)
1009 maint show target-non-stop
1010 Control whether GDB targets always operate in non-stop mode even if
1011 "set non-stop" is "off". The default is "auto", meaning non-stop
1012 mode is enabled if supported by the target.
1014 maint set bfd-sharing
1015 maint show bfd-sharing
1016 Control the reuse of bfd objects.
1019 show debug bfd-cache
1020 Control display of debugging info regarding bfd caching.
1024 Control display of debugging info regarding FreeBSD threads.
1026 set remote multiprocess-extensions-packet
1027 show remote multiprocess-extensions-packet
1028 Set/show the use of the remote protocol multiprocess extensions.
1030 set remote thread-events
1031 show remote thread-events
1032 Set/show the use of thread create/exit events.
1034 set ada print-signatures on|off
1035 show ada print-signatures"
1036 Control whether parameter types and return types are displayed in overloads
1037 selection menus. It is activaled (@code{on}) by default.
1041 Controls the maximum size of memory, in bytes, that GDB will
1042 allocate for value contents. Prevents incorrect programs from
1043 causing GDB to allocate overly large buffers. Default is 64k.
1045 * The "disassemble" command accepts a new modifier: /s.
1046 It prints mixed source+disassembly like /m with two differences:
1047 - disassembled instructions are now printed in program order, and
1048 - and source for all relevant files is now printed.
1049 The "/m" option is now considered deprecated: its "source-centric"
1050 output hasn't proved useful in practice.
1052 * The "record instruction-history" command accepts a new modifier: /s.
1053 It behaves exactly like /m and prints mixed source+disassembly.
1055 * The "set scheduler-locking" command supports a new mode "replay".
1056 It behaves like "off" in record mode and like "on" in replay mode.
1058 * Support for various ROM monitors has been removed:
1060 target dbug dBUG ROM monitor for Motorola ColdFire
1061 target picobug Motorola picobug monitor
1062 target dink32 DINK32 ROM monitor for PowerPC
1063 target m32r Renesas M32R/D ROM monitor
1064 target mon2000 mon2000 ROM monitor
1065 target ppcbug PPCBUG ROM monitor for PowerPC
1067 * Support for reading/writing memory and extracting values on architectures
1068 whose memory is addressable in units of any integral multiple of 8 bits.
1071 Allows to break when an Ada exception is handled.
1073 * New remote packets
1076 Indicates that an exec system call was executed.
1078 exec-events feature in qSupported
1079 The qSupported packet allows GDB to request support for exec
1080 events using the new 'gdbfeature' exec-event, and the qSupported
1081 response can contain the corresponding 'stubfeature'. Set and
1082 show commands can be used to display whether these features are enabled.
1085 Equivalent to interrupting with the ^C character, but works in
1088 thread created stop reason (T05 create:...)
1089 Indicates that the thread was just created and is stopped at entry.
1091 thread exit stop reply (w exitcode;tid)
1092 Indicates that the thread has terminated.
1095 Enables/disables thread create and exit event reporting. For
1096 example, this is used in non-stop mode when GDB stops a set of
1097 threads and synchronously waits for the their corresponding stop
1098 replies. Without exit events, if one of the threads exits, GDB
1099 would hang forever not knowing that it should no longer expect a
1100 stop for that same thread.
1103 Indicates that there are no resumed threads left in the target (all
1104 threads are stopped). The remote stub reports support for this stop
1105 reply to GDB's qSupported query.
1108 Enables/disables catching syscalls from the inferior process.
1109 The remote stub reports support for this packet to GDB's qSupported query.
1111 syscall_entry stop reason
1112 Indicates that a syscall was just called.
1114 syscall_return stop reason
1115 Indicates that a syscall just returned.
1117 * Extended-remote exec events
1119 ** GDB now has support for exec events on extended-remote Linux targets.
1120 For such targets with Linux kernels 2.5.46 and later, this enables
1121 follow-exec-mode and exec catchpoints.
1123 set remote exec-event-feature-packet
1124 show remote exec-event-feature-packet
1125 Set/show the use of the remote exec event feature.
1127 * Thread names in remote protocol
1129 The reply to qXfer:threads:read may now include a name attribute for each
1132 * Target remote mode fork and exec events
1134 ** GDB now has support for fork and exec events on target remote mode
1135 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1136 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1137 fork and exec catchpoints.
1139 * Remote syscall events
1141 ** GDB now has support for catch syscall on remote Linux targets,
1142 currently enabled on x86/x86_64 architectures.
1144 set remote catch-syscall-packet
1145 show remote catch-syscall-packet
1146 Set/show the use of the remote catch syscall feature.
1150 ** The -var-set-format command now accepts the zero-hexadecimal
1151 format. It outputs data in hexadecimal format with zero-padding on the
1156 ** gdb.InferiorThread objects have a new attribute "global_num",
1157 which refers to the thread's global thread ID. The existing
1158 "num" attribute now refers to the thread's per-inferior number.
1159 See "Per-inferior thread numbers" above.
1160 ** gdb.InferiorThread objects have a new attribute "inferior", which
1161 is the Inferior object the thread belongs to.
1163 *** Changes in GDB 7.10
1165 * Support for process record-replay and reverse debugging on aarch64*-linux*
1166 targets has been added. GDB now supports recording of A64 instruction set
1167 including advance SIMD instructions.
1169 * Support for Sun's version of the "stabs" debug file format has been removed.
1171 * GDB now honors the content of the file /proc/PID/coredump_filter
1172 (PID is the process ID) on GNU/Linux systems. This file can be used
1173 to specify the types of memory mappings that will be included in a
1174 corefile. For more information, please refer to the manual page of
1175 "core(5)". GDB also has a new command: "set use-coredump-filter
1176 on|off". It allows to set whether GDB will read the content of the
1177 /proc/PID/coredump_filter file when generating a corefile.
1179 * The "info os" command on GNU/Linux can now display information on
1181 "info os cpus" Listing of all cpus/cores on the system
1183 * GDB has two new commands: "set serial parity odd|even|none" and
1184 "show serial parity". These allows to set or show parity for the
1187 * The "info source" command now displays the producer string if it was
1188 present in the debug info. This typically includes the compiler version
1189 and may include things like its command line arguments.
1191 * The "info dll", an alias of the "info sharedlibrary" command,
1192 is now available on all platforms.
1194 * Directory names supplied to the "set sysroot" commands may be
1195 prefixed with "target:" to tell GDB to access shared libraries from
1196 the target system, be it local or remote. This replaces the prefix
1197 "remote:". The default sysroot has been changed from "" to
1198 "target:". "remote:" is automatically converted to "target:" for
1199 backward compatibility.
1201 * The system root specified by "set sysroot" will be prepended to the
1202 filename of the main executable (if reported to GDB as absolute by
1203 the operating system) when starting processes remotely, and when
1204 attaching to already-running local or remote processes.
1206 * GDB now supports automatic location and retrieval of executable
1207 files from remote targets. Remote debugging can now be initiated
1208 using only a "target remote" or "target extended-remote" command
1209 (no "set sysroot" or "file" commands are required). See "New remote
1212 * The "dump" command now supports verilog hex format.
1214 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1216 * On GNU/Linux, GDB and gdbserver are now able to access executable
1217 and shared library files without a "set sysroot" command when
1218 attaching to processes running in different mount namespaces from
1219 the debugger. This makes it possible to attach to processes in
1220 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1221 See "New remote packets" below.
1223 * The "tui reg" command now provides completion for all of the
1224 available register groups, including target specific groups.
1226 * The HISTSIZE environment variable is no longer read when determining
1227 the size of GDB's command history. GDB now instead reads the dedicated
1228 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1229 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1234 ** Memory ports can now be unbuffered.
1238 ** gdb.Objfile objects have a new attribute "username",
1239 which is the name of the objfile as specified by the user,
1240 without, for example, resolving symlinks.
1241 ** You can now write frame unwinders in Python.
1242 ** gdb.Type objects have a new method "optimized_out",
1243 returning optimized out gdb.Value instance of this type.
1244 ** gdb.Value objects have new methods "reference_value" and
1245 "const_value" which return a reference to the value and a
1246 "const" version of the value respectively.
1250 maint print symbol-cache
1251 Print the contents of the symbol cache.
1253 maint print symbol-cache-statistics
1254 Print statistics of symbol cache usage.
1256 maint flush-symbol-cache
1257 Flush the contents of the symbol cache.
1261 Start branch trace recording using Branch Trace Store (BTS) format.
1264 Evaluate expression by using the compiler and print result.
1268 Explicit commands for enabling and disabling tui mode.
1271 set mpx bound on i386 and amd64
1272 Support for bound table investigation on Intel MPX enabled applications.
1276 Start branch trace recording using Intel Processor Trace format.
1279 Print information about branch tracing internals.
1281 maint btrace packet-history
1282 Print the raw branch tracing data.
1284 maint btrace clear-packet-history
1285 Discard the stored raw branch tracing data.
1288 Discard all branch tracing data. It will be fetched and processed
1289 anew by the next "record" command.
1294 Renamed from "set debug dwarf2-die".
1295 show debug dwarf-die
1296 Renamed from "show debug dwarf2-die".
1298 set debug dwarf-read
1299 Renamed from "set debug dwarf2-read".
1300 show debug dwarf-read
1301 Renamed from "show debug dwarf2-read".
1303 maint set dwarf always-disassemble
1304 Renamed from "maint set dwarf2 always-disassemble".
1305 maint show dwarf always-disassemble
1306 Renamed from "maint show dwarf2 always-disassemble".
1308 maint set dwarf max-cache-age
1309 Renamed from "maint set dwarf2 max-cache-age".
1310 maint show dwarf max-cache-age
1311 Renamed from "maint show dwarf2 max-cache-age".
1313 set debug dwarf-line
1314 show debug dwarf-line
1315 Control display of debugging info regarding DWARF line processing.
1318 show max-completions
1319 Set the maximum number of candidates to be considered during
1320 completion. The default value is 200. This limit allows GDB
1321 to avoid generating large completion lists, the computation of
1322 which can cause the debugger to become temporarily unresponsive.
1324 set history remove-duplicates
1325 show history remove-duplicates
1326 Control the removal of duplicate history entries.
1328 maint set symbol-cache-size
1329 maint show symbol-cache-size
1330 Control the size of the symbol cache.
1332 set|show record btrace bts buffer-size
1333 Set and show the size of the ring buffer used for branch tracing in
1335 The obtained size may differ from the requested size. Use "info
1336 record" to see the obtained buffer size.
1338 set debug linux-namespaces
1339 show debug linux-namespaces
1340 Control display of debugging info regarding Linux namespaces.
1342 set|show record btrace pt buffer-size
1343 Set and show the size of the ring buffer used for branch tracing in
1344 Intel Processor Trace format.
1345 The obtained size may differ from the requested size. Use "info
1346 record" to see the obtained buffer size.
1348 maint set|show btrace pt skip-pad
1349 Set and show whether PAD packets are skipped when computing the
1352 * The command 'thread apply all' can now support new option '-ascending'
1353 to call its specified command for all threads in ascending order.
1355 * Python/Guile scripting
1357 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1358 special section named `.debug_gdb_scripts'.
1360 * New remote packets
1362 qXfer:btrace-conf:read
1363 Return the branch trace configuration for the current thread.
1365 Qbtrace-conf:bts:size
1366 Set the requested ring buffer size for branch tracing in BTS format.
1369 Enable Intel Procesor Trace-based branch tracing for the current
1370 process. The remote stub reports support for this packet to GDB's
1373 Qbtrace-conf:pt:size
1374 Set the requested ring buffer size for branch tracing in Intel Processor
1378 Indicates a memory breakpoint instruction was executed, irrespective
1379 of whether it was GDB that planted the breakpoint or the breakpoint
1380 is hardcoded in the program. This is required for correct non-stop
1384 Indicates the target stopped for a hardware breakpoint. This is
1385 required for correct non-stop mode operation.
1388 Return information about files on the remote system.
1390 qXfer:exec-file:read
1391 Return the full absolute name of the file that was executed to
1392 create a process running on the remote system.
1395 Select the filesystem on which vFile: operations with filename
1396 arguments will operate. This is required for GDB to be able to
1397 access files on remote targets where the remote stub does not
1398 share a common filesystem with the inferior(s).
1401 Indicates that a fork system call was executed.
1404 Indicates that a vfork system call was executed.
1406 vforkdone stop reason
1407 Indicates that a vfork child of the specified process has executed
1408 an exec or exit, allowing the vfork parent to resume execution.
1410 fork-events and vfork-events features in qSupported
1411 The qSupported packet allows GDB to request support for fork and
1412 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1413 and the qSupported response can contain the corresponding
1414 'stubfeatures'. Set and show commands can be used to display
1415 whether these features are enabled.
1417 * Extended-remote fork events
1419 ** GDB now has support for fork events on extended-remote Linux
1420 targets. For targets with Linux kernels 2.5.60 and later, this
1421 enables follow-fork-mode and detach-on-fork for both fork and
1422 vfork, as well as fork and vfork catchpoints.
1424 * The info record command now shows the recording format and the
1425 branch tracing configuration for the current thread when using
1426 the btrace record target.
1427 For the BTS format, it shows the ring buffer size.
1429 * GDB now has support for DTrace USDT (Userland Static Defined
1430 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1432 * GDB now supports access to vector registers on S/390 GNU/Linux
1435 * Removed command line options
1437 -xdb HP-UX XDB compatibility mode.
1439 * Removed targets and native configurations
1441 HP/PA running HP-UX hppa*-*-hpux*
1442 Itanium running HP-UX ia64-*-hpux*
1444 * New configure options
1447 This configure option allows the user to build GDB with support for
1448 Intel Processor Trace (default: auto). This requires libipt.
1450 --with-libipt-prefix=PATH
1451 Specify the path to the version of libipt that GDB should use.
1452 $PATH/include should contain the intel-pt.h header and
1453 $PATH/lib should contain the libipt.so library.
1455 *** Changes in GDB 7.9.1
1459 ** Xmethods can now specify a result type.
1461 *** Changes in GDB 7.9
1463 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1467 ** You can now access frame registers from Python scripts.
1468 ** New attribute 'producer' for gdb.Symtab objects.
1469 ** gdb.Objfile objects have a new attribute "progspace",
1470 which is the gdb.Progspace object of the containing program space.
1471 ** gdb.Objfile objects have a new attribute "owner".
1472 ** gdb.Objfile objects have a new attribute "build_id",
1473 which is the build ID generated when the file was built.
1474 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1475 ** A new event "gdb.clear_objfiles" has been added, triggered when
1476 selecting a new file to debug.
1477 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1478 ** New function gdb.lookup_objfile.
1480 New events which are triggered when GDB modifies the state of the
1483 ** gdb.events.inferior_call_pre: Function call is about to be made.
1484 ** gdb.events.inferior_call_post: Function call has just been made.
1485 ** gdb.events.memory_changed: A memory location has been altered.
1486 ** gdb.events.register_changed: A register has been altered.
1488 * New Python-based convenience functions:
1490 ** $_caller_is(name [, number_of_frames])
1491 ** $_caller_matches(regexp [, number_of_frames])
1492 ** $_any_caller_is(name [, number_of_frames])
1493 ** $_any_caller_matches(regexp [, number_of_frames])
1495 * GDB now supports the compilation and injection of source code into
1496 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1497 to compile the source code to object code, and if successful, inject
1498 and execute that code within the current context of the inferior.
1499 Currently the C language is supported. The commands used to
1500 interface with this new feature are:
1502 compile code [-raw|-r] [--] [source code]
1503 compile file [-raw|-r] filename
1507 demangle [-l language] [--] name
1508 Demangle "name" in the specified language, or the current language
1509 if elided. This command is renamed from the "maint demangle" command.
1510 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1511 as "maint demangler-warning".
1513 queue-signal signal-name-or-number
1514 Queue a signal to be delivered to the thread when it is resumed.
1516 add-auto-load-scripts-directory directory
1517 Add entries to the list of directories from which to load auto-loaded
1520 maint print user-registers
1521 List all currently available "user" registers.
1523 compile code [-r|-raw] [--] [source code]
1524 Compile, inject, and execute in the inferior the executable object
1525 code produced by compiling the provided source code.
1527 compile file [-r|-raw] filename
1528 Compile and inject into the inferior the executable object code
1529 produced by compiling the source code stored in the filename
1532 * On resume, GDB now always passes the signal the program had stopped
1533 for to the thread the signal was sent to, even if the user changed
1534 threads before resuming. Previously GDB would often (but not
1535 always) deliver the signal to the thread that happens to be current
1538 * Conversely, the "signal" command now consistently delivers the
1539 requested signal to the current thread. GDB now asks for
1540 confirmation if the program had stopped for a signal and the user
1541 switched threads meanwhile.
1543 * "breakpoint always-inserted" modes "off" and "auto" merged.
1545 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1546 won't remove breakpoints from the target until all threads stop,
1547 even in non-stop mode. The "auto" mode has been removed, and "off"
1548 is now the default mode.
1552 set debug symbol-lookup
1553 show debug symbol-lookup
1554 Control display of debugging info regarding symbol lookup.
1558 ** The -list-thread-groups command outputs an exit-code field for
1559 inferiors that have exited.
1563 MIPS SDE mips*-sde*-elf*
1567 Support for these obsolete configurations has been removed.
1569 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1570 SGI Irix-5.x mips-*-irix5*
1571 SGI Irix-6.x mips-*-irix6*
1572 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1573 VAX running Ultrix vax-*-ultrix*
1575 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1576 and "assf"), have been removed. Use the "sharedlibrary" command, or
1577 its alias "share", instead.
1579 *** Changes in GDB 7.8
1581 * New command line options
1584 This is an alias for the --data-directory option.
1586 * GDB supports printing and modifying of variable length automatic arrays
1587 as specified in ISO C99.
1589 * The ARM simulator now supports instruction level tracing
1590 with or without disassembly.
1594 GDB now has support for scripting using Guile. Whether this is
1595 available is determined at configure time.
1596 Guile version 2.0 or greater is required.
1597 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1599 * New commands (for set/show, see "New options" below)
1603 Invoke CODE by passing it to the Guile interpreter.
1607 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1609 info auto-load guile-scripts [regexp]
1610 Print the list of automatically loaded Guile scripts.
1612 * The source command is now capable of sourcing Guile scripts.
1613 This feature is dependent on the debugger being built with Guile support.
1617 set print symbol-loading (off|brief|full)
1618 show print symbol-loading
1619 Control whether to print informational messages when loading symbol
1620 information for a file. The default is "full", but when debugging
1621 programs with large numbers of shared libraries the amount of output
1622 becomes less useful.
1624 set guile print-stack (none|message|full)
1625 show guile print-stack
1626 Show a stack trace when an error is encountered in a Guile script.
1628 set auto-load guile-scripts (on|off)
1629 show auto-load guile-scripts
1630 Control auto-loading of Guile script files.
1632 maint ada set ignore-descriptive-types (on|off)
1633 maint ada show ignore-descriptive-types
1634 Control whether the debugger should ignore descriptive types in Ada
1635 programs. The default is not to ignore the descriptive types. See
1636 the user manual for more details on descriptive types and the intended
1637 usage of this option.
1639 set auto-connect-native-target
1641 Control whether GDB is allowed to automatically connect to the
1642 native target for the run, attach, etc. commands when not connected
1643 to any target yet. See also "target native" below.
1645 set record btrace replay-memory-access (read-only|read-write)
1646 show record btrace replay-memory-access
1647 Control what memory accesses are allowed during replay.
1649 maint set target-async (on|off)
1650 maint show target-async
1651 This controls whether GDB targets operate in synchronous or
1652 asynchronous mode. Normally the default is asynchronous, if it is
1653 available; but this can be changed to more easily debug problems
1654 occurring only in synchronous mode.
1656 set mi-async (on|off)
1658 Control whether MI asynchronous mode is preferred. This supersedes
1659 "set target-async" of previous GDB versions.
1661 * "set target-async" is deprecated as a CLI option and is now an alias
1662 for "set mi-async" (only puts MI into async mode).
1664 * Background execution commands (e.g., "c&", "s&", etc.) are now
1665 possible ``out of the box'' if the target supports them. Previously
1666 the user would need to explicitly enable the possibility with the
1667 "set target-async on" command.
1669 * New features in the GDB remote stub, GDBserver
1671 ** New option --debug-format=option1[,option2,...] allows one to add
1672 additional text to each output. At present only timestamps
1673 are supported: --debug-format=timestamps.
1674 Timestamps can also be turned on with the
1675 "monitor set debug-format timestamps" command from GDB.
1677 * The 'record instruction-history' command now starts counting instructions
1678 at one. This also affects the instruction ranges reported by the
1679 'record function-call-history' command when given the /i modifier.
1681 * The command 'record function-call-history' supports a new modifier '/c' to
1682 indent the function names based on their call stack depth.
1683 The fields for the '/i' and '/l' modifier have been reordered.
1684 The source line range is now prefixed with 'at'.
1685 The instruction range is now prefixed with 'inst'.
1686 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1687 "record instruction-history" and "list" commands.
1689 * The ranges given as arguments to the 'record function-call-history' and
1690 'record instruction-history' commands are now inclusive.
1692 * The btrace record target now supports the 'record goto' command.
1693 For locations inside the execution trace, the back trace is computed
1694 based on the information stored in the execution trace.
1696 * The btrace record target supports limited reverse execution and replay.
1697 The target does not record data and therefore does not allow reading
1698 memory or registers.
1700 * The "catch syscall" command now works on s390*-linux* targets.
1702 * The "compare-sections" command is no longer specific to target
1703 remote. It now works with all targets.
1705 * All native targets are now consistently called "native".
1706 Consequently, the "target child", "target GNU", "target djgpp",
1707 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1708 commands have been replaced with "target native". The QNX/NTO port
1709 leaves the "procfs" target in place and adds a "native" target for
1710 consistency with other ports. The impact on users should be minimal
1711 as these commands previously either throwed an error, or were
1712 no-ops. The target's name is visible in the output of the following
1713 commands: "help target", "info target", "info files", "maint print
1716 * The "target native" command now connects to the native target. This
1717 can be used to launch native programs even when "set
1718 auto-connect-native-target" is set to off.
1720 * GDB now supports access to Intel MPX registers on GNU/Linux.
1722 * Support for Intel AVX-512 registers on GNU/Linux.
1723 Support displaying and modifying Intel AVX-512 registers
1724 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1726 * New remote packets
1728 qXfer:btrace:read's annex
1729 The qXfer:btrace:read packet supports a new annex 'delta' to read
1730 branch trace incrementally.
1734 ** Valid Python operations on gdb.Value objects representing
1735 structs/classes invoke the corresponding overloaded operators if
1737 ** New `Xmethods' feature in the Python API. Xmethods are
1738 additional methods or replacements for existing methods of a C++
1739 class. This feature is useful for those cases where a method
1740 defined in C++ source code could be inlined or optimized out by
1741 the compiler, making it unavailable to GDB.
1744 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1746 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1747 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1748 its alias "share", instead.
1750 * The commands "set remotebaud" and "show remotebaud" are no longer
1751 supported. Use "set serial baud" and "show serial baud" (respectively)
1756 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1757 target-async". The latter is left as a deprecated alias of the
1758 former for backward compatibility. If the target supports it,
1759 CLI background execution commands are now always possible by
1760 default, independently of whether the frontend stated a
1761 preference for asynchronous execution with "-gdb-set mi-async".
1762 Previously "-gdb-set target-async off" affected both MI execution
1763 commands and CLI execution commands.
1765 *** Changes in GDB 7.7
1767 * Improved support for process record-replay and reverse debugging on
1768 arm*-linux* targets. Support for thumb32 and syscall instruction
1769 recording has been added.
1771 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1773 * GDB now supports Fission DWP file format version 2.
1774 http://gcc.gnu.org/wiki/DebugFission
1776 * New convenience function "$_isvoid", to check whether an expression
1777 is void. A void expression is an expression where the type of the
1778 result is "void". For example, some convenience variables may be
1779 "void" when evaluated (e.g., "$_exitcode" before the execution of
1780 the program being debugged; or an undefined convenience variable).
1781 Another example, when calling a function whose return type is
1784 * The "maintenance print objfiles" command now takes an optional regexp.
1786 * The "catch syscall" command now works on arm*-linux* targets.
1788 * GDB now consistently shows "<not saved>" when printing values of
1789 registers the debug info indicates have not been saved in the frame
1790 and there's nowhere to retrieve them from
1791 (callee-saved/call-clobbered registers):
1796 (gdb) info registers rax
1799 Before, the former would print "<optimized out>", and the latter
1800 "*value not available*".
1802 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1807 ** Frame filters and frame decorators have been added.
1808 ** Temporary breakpoints are now supported.
1809 ** Line tables representation has been added.
1810 ** New attribute 'parent_type' for gdb.Field objects.
1811 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1812 ** New attribute 'name' for gdb.Type objects.
1816 Nios II ELF nios2*-*-elf
1817 Nios II GNU/Linux nios2*-*-linux
1818 Texas Instruments MSP430 msp430*-*-elf
1820 * Removed native configurations
1822 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1823 been removed. ELF variants of these configurations are kept supported.
1825 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1826 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1827 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1828 i[34567]86-*-openbsd3.[0-3]
1829 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1830 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1831 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1835 Like "catch throw", but catches a re-thrown exception.
1836 maint check-psymtabs
1837 Renamed from old "maint check-symtabs".
1839 Perform consistency checks on symtabs.
1840 maint expand-symtabs
1841 Expand symtabs matching an optional regexp.
1844 Display the details of GDB configure-time options.
1846 maint set|show per-command
1847 maint set|show per-command space
1848 maint set|show per-command time
1849 maint set|show per-command symtab
1850 Enable display of per-command gdb resource usage.
1852 remove-symbol-file FILENAME
1853 remove-symbol-file -a ADDRESS
1854 Remove a symbol file added via add-symbol-file. The file to remove
1855 can be identified by its filename or by an address that lies within
1856 the boundaries of this symbol file in memory.
1859 info exceptions REGEXP
1860 Display the list of Ada exceptions defined in the program being
1861 debugged. If provided, only the exceptions whose names match REGEXP
1866 set debug symfile off|on
1868 Control display of debugging info regarding reading symbol files and
1869 symbol tables within those files
1871 set print raw frame-arguments
1872 show print raw frame-arguments
1873 Set/show whether to print frame arguments in raw mode,
1874 disregarding any defined pretty-printers.
1876 set remote trace-status-packet
1877 show remote trace-status-packet
1878 Set/show the use of remote protocol qTStatus packet.
1882 Control display of debugging messages related to Nios II targets.
1886 Control whether target-assisted range stepping is enabled.
1888 set startup-with-shell
1889 show startup-with-shell
1890 Specifies whether Unix child processes are started via a shell or
1895 Use the target memory cache for accesses to the code segment. This
1896 improves performance of remote debugging (particularly disassembly).
1898 * You can now use a literal value 'unlimited' for options that
1899 interpret 0 or -1 as meaning "unlimited". E.g., "set
1900 trace-buffer-size unlimited" is now an alias for "set
1901 trace-buffer-size -1" and "set height unlimited" is now an alias for
1904 * The "set debug symtab-create" debugging option of GDB has been changed to
1905 accept a verbosity level. 0 means "off", 1 provides basic debugging
1906 output, and values of 2 or greater provides more verbose output.
1908 * New command-line options
1910 Display the details of GDB configure-time options.
1912 * The command 'tsave' can now support new option '-ctf' to save trace
1913 buffer in Common Trace Format.
1915 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1918 * GDB now implements the the C++ 'typeid' operator.
1920 * The new convenience variable $_exception holds the exception being
1921 thrown or caught at an exception-related catchpoint.
1923 * The exception-related catchpoints, like "catch throw", now accept a
1924 regular expression which can be used to filter exceptions by type.
1926 * The new convenience variable $_exitsignal is automatically set to
1927 the terminating signal number when the program being debugged dies
1928 due to an uncaught signal.
1932 ** All MI commands now accept an optional "--language" option.
1933 Support for this feature can be verified by using the "-list-features"
1934 command, which should contain "language-option".
1936 ** The new command -info-gdb-mi-command allows the user to determine
1937 whether a GDB/MI command is supported or not.
1939 ** The "^error" result record returned when trying to execute an undefined
1940 GDB/MI command now provides a variable named "code" whose content is the
1941 "undefined-command" error code. Support for this feature can be verified
1942 by using the "-list-features" command, which should contain
1943 "undefined-command-error-code".
1945 ** The -trace-save MI command can optionally save trace buffer in Common
1948 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1950 ** The command -data-list-register-values now accepts an optional
1951 "--skip-unavailable" option. When used, only the available registers
1954 ** The new command -trace-frame-collected dumps collected variables,
1955 computed expressions, tvars, memory and registers in a traceframe.
1957 ** The commands -stack-list-locals, -stack-list-arguments and
1958 -stack-list-variables now accept an option "--skip-unavailable".
1959 When used, only the available locals or arguments are displayed.
1961 ** The -exec-run command now accepts an optional "--start" option.
1962 When used, the command follows the same semantics as the "start"
1963 command, stopping the program's execution at the start of its
1964 main subprogram. Support for this feature can be verified using
1965 the "-list-features" command, which should contain
1966 "exec-run-start-option".
1968 ** The new commands -catch-assert and -catch-exceptions insert
1969 catchpoints stopping the program when Ada exceptions are raised.
1971 ** The new command -info-ada-exceptions provides the equivalent of
1972 the new "info exceptions" command.
1974 * New system-wide configuration scripts
1975 A GDB installation now provides scripts suitable for use as system-wide
1976 configuration scripts for the following systems:
1980 * GDB now supports target-assigned range stepping with remote targets.
1981 This improves the performance of stepping source lines by reducing
1982 the number of control packets from/to GDB. See "New remote packets"
1985 * GDB now understands the element 'tvar' in the XML traceframe info.
1986 It has the id of the collected trace state variables.
1988 * On S/390 targets that provide the transactional-execution feature,
1989 the program interruption transaction diagnostic block (TDB) is now
1990 represented as a number of additional "registers" in GDB.
1992 * New remote packets
1996 The vCont packet supports a new 'r' action, that tells the remote
1997 stub to step through an address range itself, without GDB
1998 involvemement at each single-step.
2000 qXfer:libraries-svr4:read's annex
2001 The previously unused annex of the qXfer:libraries-svr4:read packet
2002 is now used to support passing an argument list. The remote stub
2003 reports support for this argument list to GDB's qSupported query.
2004 The defined arguments are "start" and "prev", used to reduce work
2005 necessary for library list updating, resulting in significant
2008 * New features in the GDB remote stub, GDBserver
2010 ** GDBserver now supports target-assisted range stepping. Currently
2011 enabled on x86/x86_64 GNU/Linux targets.
2013 ** GDBserver now adds element 'tvar' in the XML in the reply to
2014 'qXfer:traceframe-info:read'. It has the id of the collected
2015 trace state variables.
2017 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2020 * New 'z' formatter for printing and examining memory, this displays the
2021 value as hexadecimal zero padded on the left to the size of the type.
2023 * GDB can now use Windows x64 unwinding data.
2025 * The "set remotebaud" command has been replaced by "set serial baud".
2026 Similarly, "show remotebaud" has been replaced by "show serial baud".
2027 The "set remotebaud" and "show remotebaud" commands are still available
2028 to provide backward compatibility with older versions of GDB.
2030 *** Changes in GDB 7.6
2032 * Target record has been renamed to record-full.
2033 Record/replay is now enabled with the "record full" command.
2034 This also affects settings that are associated with full record/replay
2035 that have been moved from "set/show record" to "set/show record full":
2037 set|show record full insn-number-max
2038 set|show record full stop-at-limit
2039 set|show record full memory-query
2041 * A new record target "record-btrace" has been added. The new target
2042 uses hardware support to record the control-flow of a process. It
2043 does not support replaying the execution, but it implements the
2044 below new commands for investigating the recorded execution log.
2045 This new recording method can be enabled using:
2049 The "record-btrace" target is only available on Intel Atom processors
2050 and requires a Linux kernel 2.6.32 or later.
2052 * Two new commands have been added for record/replay to give information
2053 about the recorded execution without having to replay the execution.
2054 The commands are only supported by "record btrace".
2056 record instruction-history prints the execution history at
2057 instruction granularity
2059 record function-call-history prints the execution history at
2060 function granularity
2062 * New native configurations
2064 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2065 FreeBSD/powerpc powerpc*-*-freebsd
2066 x86_64/Cygwin x86_64-*-cygwin*
2067 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2071 ARM AArch64 aarch64*-*-elf
2072 ARM AArch64 GNU/Linux aarch64*-*-linux
2073 Lynx 178 PowerPC powerpc-*-lynx*178
2074 x86_64/Cygwin x86_64-*-cygwin*
2075 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2077 * If the configured location of system.gdbinit file (as given by the
2078 --with-system-gdbinit option at configure time) is in the
2079 data-directory (as specified by --with-gdb-datadir at configure
2080 time) or in one of its subdirectories, then GDB will look for the
2081 system-wide init file in the directory specified by the
2082 --data-directory command-line option.
2084 * New command line options:
2086 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2087 other initialization files, unlike -nx which disables all of them.
2089 * Removed command line options
2091 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2094 * The 'ptype' and 'whatis' commands now accept an argument to control
2097 * 'info proc' now works on some core files.
2101 ** Vectors can be created with gdb.Type.vector.
2103 ** Python's atexit.register now works in GDB.
2105 ** Types can be pretty-printed via a Python API.
2107 ** Python 3 is now supported (in addition to Python 2.4 or later)
2109 ** New class gdb.Architecture exposes GDB's internal representation
2110 of architecture in the Python API.
2112 ** New method Frame.architecture returns the gdb.Architecture object
2113 corresponding to the frame's architecture.
2115 * New Python-based convenience functions:
2117 ** $_memeq(buf1, buf2, length)
2118 ** $_streq(str1, str2)
2120 ** $_regex(str, regex)
2122 * The 'cd' command now defaults to using '~' (the home directory) if not
2125 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2126 default for GCC since November 2000.
2128 * The command 'forward-search' can now be abbreviated as 'fo'.
2130 * The command 'info tracepoints' can now display 'installed on target'
2131 or 'not installed on target' for each non-pending location of tracepoint.
2133 * New configure options
2135 --enable-libmcheck/--disable-libmcheck
2136 By default, development versions are built with -lmcheck on hosts
2137 that support it, in order to help track memory corruption issues.
2138 Release versions, on the other hand, are built without -lmcheck
2139 by default. The --enable-libmcheck/--disable-libmcheck configure
2140 options allow the user to override that default.
2141 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2142 This configure option allows the user to build GDB with
2143 libbabeltrace using which GDB can read Common Trace Format data.
2145 * New commands (for set/show, see "New options" below)
2148 Catch signals. This is similar to "handle", but allows commands and
2149 conditions to be attached.
2152 List the BFDs known to GDB.
2154 python-interactive [command]
2156 Start a Python interactive prompt, or evaluate the optional command
2157 and print the result of expressions.
2160 "py" is a new alias for "python".
2162 enable type-printer [name]...
2163 disable type-printer [name]...
2164 Enable or disable type printers.
2168 ** For the Renesas Super-H architecture, the "regs" command has been removed
2169 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2174 set print type methods (on|off)
2175 show print type methods
2176 Control whether method declarations are displayed by "ptype".
2177 The default is to show them.
2179 set print type typedefs (on|off)
2180 show print type typedefs
2181 Control whether typedef definitions are displayed by "ptype".
2182 The default is to show them.
2184 set filename-display basename|relative|absolute
2185 show filename-display
2186 Control the way in which filenames is displayed.
2187 The default is "relative", which preserves previous behavior.
2189 set trace-buffer-size
2190 show trace-buffer-size
2191 Request target to change the size of trace buffer.
2193 set remote trace-buffer-size-packet auto|on|off
2194 show remote trace-buffer-size-packet
2195 Control the use of the remote protocol `QTBuffer:size' packet.
2199 Control display of debugging messages related to ARM AArch64.
2202 set debug coff-pe-read
2203 show debug coff-pe-read
2204 Control display of debugging messages related to reading of COFF/PE
2209 Control display of debugging messages related to Mach-O symbols
2212 set debug notification
2213 show debug notification
2214 Control display of debugging info for async remote notification.
2218 ** Command parameter changes are now notified using new async record
2219 "=cmd-param-changed".
2220 ** Trace frame changes caused by command "tfind" are now notified using
2221 new async record "=traceframe-changed".
2222 ** The creation, deletion and modification of trace state variables
2223 are now notified using new async records "=tsv-created",
2224 "=tsv-deleted" and "=tsv-modified".
2225 ** The start and stop of process record are now notified using new
2226 async record "=record-started" and "=record-stopped".
2227 ** Memory changes are now notified using new async record
2229 ** The data-disassemble command response will include a "fullname" field
2230 containing the absolute file name when source has been requested.
2231 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2232 command, to allow pattern filling of memory areas.
2233 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2234 library load/unload events.
2235 ** The response to breakpoint commands and breakpoint async records
2236 includes an "installed" field containing a boolean state about each
2237 non-pending tracepoint location is whether installed on target or not.
2238 ** Output of the "-trace-status" command includes a "trace-file" field
2239 containing the name of the trace file being examined. This field is
2240 optional, and only present when examining a trace file.
2241 ** The "fullname" field is now always present along with the "file" field,
2242 even if the file cannot be found by GDB.
2244 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2245 You must have the LZMA library available when configuring GDB for this
2246 feature to be enabled. For more information, see:
2247 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2249 * New remote packets
2252 Set the size of trace buffer. The remote stub reports support for this
2253 packet to gdb's qSupported query.
2256 Enable Branch Trace Store (BTS)-based branch tracing for the current
2257 thread. The remote stub reports support for this packet to gdb's
2261 Disable branch tracing for the current thread. The remote stub reports
2262 support for this packet to gdb's qSupported query.
2265 Read the traced branches for the current thread. The remote stub
2266 reports support for this packet to gdb's qSupported query.
2268 *** Changes in GDB 7.5
2270 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2271 for more x32 ABI info.
2273 * GDB now supports access to MIPS DSP registers on Linux targets.
2275 * GDB now supports debugging microMIPS binaries.
2277 * The "info os" command on GNU/Linux can now display information on
2278 several new classes of objects managed by the operating system:
2279 "info os procgroups" lists process groups
2280 "info os files" lists file descriptors
2281 "info os sockets" lists internet-domain sockets
2282 "info os shm" lists shared-memory regions
2283 "info os semaphores" lists semaphores
2284 "info os msg" lists message queues
2285 "info os modules" lists loaded kernel modules
2287 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2288 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2289 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2290 options and inspect the probe arguments using the new $_probe_arg family
2291 of convenience variables. You can obtain more information about SystemTap
2292 in <http://sourceware.org/systemtap/>.
2294 * GDB now supports reversible debugging on ARM, it allows you to
2295 debug basic ARM and THUMB instructions, and provides
2296 record/replay support.
2298 * The option "symbol-reloading" has been deleted as it is no longer used.
2302 ** GDB commands implemented in Python can now be put in command class
2305 ** The "maint set python print-stack on|off" is now deleted.
2307 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2308 apply "flag enum"-style pretty-printing to any enum.
2310 ** gdb.lookup_symbol can now work when there is no current frame.
2312 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2313 the source at which the symbol was defined.
2315 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2316 method 'value'. The former indicates whether the symbol needs a
2317 frame in order to compute its value, and the latter computes the
2320 ** A new method 'referenced_value' on gdb.Value objects which can
2321 dereference pointer as well as C++ reference values.
2323 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2324 which return the global and static blocks (as gdb.Block objects),
2325 of the underlying symbol table, respectively.
2327 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2328 object associated with a PC value.
2330 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2331 of the address range occupied by code for the current source line.
2333 * Go language support.
2334 GDB now supports debugging programs written in the Go programming
2337 * GDBserver now supports stdio connections.
2338 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2340 * The binary "gdbtui" can no longer be built or installed.
2341 Use "gdb -tui" instead.
2343 * GDB will now print "flag" enums specially. A flag enum is one where
2344 all the enumerator values have no bits in common when pairwise
2345 "and"ed. When printing a value whose type is a flag enum, GDB will
2346 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2347 (gdb) print (enum E) 3
2350 * The filename part of a linespec will now match trailing components
2351 of a source file name. For example, "break gcc/expr.c:1000" will
2352 now set a breakpoint in build/gcc/expr.c, but not
2353 build/libcpp/expr.c.
2355 * The "info proc" and "generate-core-file" commands will now also
2356 work on remote targets connected to GDBserver on Linux.
2358 * The command "info catch" has been removed. It has been disabled
2359 since December 2007.
2361 * The "catch exception" and "catch assert" commands now accept
2362 a condition at the end of the command, much like the "break"
2363 command does. For instance:
2365 (gdb) catch exception Constraint_Error if Barrier = True
2367 Previously, it was possible to add a condition to such catchpoints,
2368 but it had to be done as a second step, after the catchpoint had been
2369 created, using the "condition" command.
2371 * The "info static-tracepoint-marker" command will now also work on
2372 native Linux targets with in-process agent.
2374 * GDB can now set breakpoints on inlined functions.
2376 * The .gdb_index section has been updated to include symbols for
2377 inlined functions. GDB will ignore older .gdb_index sections by
2378 default, which could cause symbol files to be loaded more slowly
2379 until their .gdb_index sections can be recreated. The new command
2380 "set use-deprecated-index-sections on" will cause GDB to use any older
2381 .gdb_index sections it finds. This will restore performance, but the
2382 ability to set breakpoints on inlined functions will be lost in symbol
2383 files with older .gdb_index sections.
2385 The .gdb_index section has also been updated to record more information
2386 about each symbol. This speeds up the "info variables", "info functions"
2387 and "info types" commands when used with programs having the .gdb_index
2388 section, as well as speeding up debugging with shared libraries using
2389 the .gdb_index section.
2391 * Ada support for GDB/MI Variable Objects has been added.
2393 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2398 ** New command -info-os is the MI equivalent of "info os".
2400 ** Output logs ("set logging" and related) now include MI output.
2404 ** "set use-deprecated-index-sections on|off"
2405 "show use-deprecated-index-sections on|off"
2406 Controls the use of deprecated .gdb_index sections.
2408 ** "catch load" and "catch unload" can be used to stop when a shared
2409 library is loaded or unloaded, respectively.
2411 ** "enable count" can be used to auto-disable a breakpoint after
2414 ** "info vtbl" can be used to show the virtual method tables for
2415 C++ and Java objects.
2417 ** "explore" and its sub commands "explore value" and "explore type"
2418 can be used to recursively explore values and types of
2419 expressions. These commands are available only if GDB is
2420 configured with '--with-python'.
2422 ** "info auto-load" shows status of all kinds of auto-loaded files,
2423 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2424 sequences of commands files, "info auto-load python-scripts"
2425 shows status of auto-loading Python script files,
2426 "info auto-load local-gdbinit" shows status of loading init file
2427 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2428 status of inferior specific thread debugging shared library loading.
2430 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2431 and "show auto-load-scripts" commands have been deprecated, use their
2432 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2433 and "show auto-load python-scripts" counterparts instead.
2435 ** "dprintf location,format,args..." creates a dynamic printf, which
2436 is basically a breakpoint that does a printf and immediately
2437 resumes your program's execution, so it is like a printf that you
2438 can insert dynamically at runtime instead of at compiletime.
2440 ** "set print symbol"
2442 Controls whether GDB attempts to display the symbol, if any,
2443 corresponding to addresses it prints. This defaults to "on", but
2444 you can set it to "off" to restore GDB's previous behavior.
2446 * Deprecated commands
2448 ** For the Renesas Super-H architecture, the "regs" command has been
2449 deprecated, and "info all-registers" should be used instead.
2453 Renesas RL78 rl78-*-elf
2454 HP OpenVMS ia64 ia64-hp-openvms*
2456 * GDBserver supports evaluation of breakpoint conditions. When
2457 support is advertised by GDBserver, GDB may be told to send the
2458 breakpoint conditions in bytecode form to GDBserver. GDBserver
2459 will only report the breakpoint trigger to GDB when its condition
2464 set mips compression
2465 show mips compression
2466 Select the compressed ISA encoding used in functions that have no symbol
2467 information available. The encoding can be set to either of:
2470 and is updated automatically from ELF file flags if available.
2472 set breakpoint condition-evaluation
2473 show breakpoint condition-evaluation
2474 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2475 GDBserver ("target"). Default option "auto" chooses the most efficient
2477 This option can improve debugger efficiency depending on the speed of the
2481 Disable auto-loading globally.
2484 Show auto-loading setting of all kinds of auto-loaded files.
2486 set auto-load gdb-scripts on|off
2487 show auto-load gdb-scripts
2488 Control auto-loading of GDB canned sequences of commands files.
2490 set auto-load python-scripts on|off
2491 show auto-load python-scripts
2492 Control auto-loading of Python script files.
2494 set auto-load local-gdbinit on|off
2495 show auto-load local-gdbinit
2496 Control loading of init file (.gdbinit) from current directory.
2498 set auto-load libthread-db on|off
2499 show auto-load libthread-db
2500 Control auto-loading of inferior specific thread debugging shared library.
2502 set auto-load scripts-directory <dir1>[:<dir2>...]
2503 show auto-load scripts-directory
2504 Set a list of directories from which to load auto-loaded scripts.
2505 Automatically loaded Python scripts and GDB scripts are located in one
2506 of the directories listed by this option.
2507 The delimiter (':' above) may differ according to the host platform.
2509 set auto-load safe-path <dir1>[:<dir2>...]
2510 show auto-load safe-path
2511 Set a list of directories from which it is safe to auto-load files.
2512 The delimiter (':' above) may differ according to the host platform.
2514 set debug auto-load on|off
2515 show debug auto-load
2516 Control display of debugging info for auto-loading the files above.
2518 set dprintf-style gdb|call|agent
2520 Control the way in which a dynamic printf is performed; "gdb"
2521 requests a GDB printf command, while "call" causes dprintf to call a
2522 function in the inferior. "agent" requests that the target agent
2523 (such as GDBserver) do the printing.
2525 set dprintf-function <expr>
2526 show dprintf-function
2527 set dprintf-channel <expr>
2528 show dprintf-channel
2529 Set the function and optional first argument to the call when using
2530 the "call" style of dynamic printf.
2532 set disconnected-dprintf on|off
2533 show disconnected-dprintf
2534 Control whether agent-style dynamic printfs continue to be in effect
2535 after GDB disconnects.
2537 * New configure options
2539 --with-auto-load-dir
2540 Configure default value for the 'set auto-load scripts-directory'
2541 setting above. It defaults to '$debugdir:$datadir/auto-load',
2542 $debugdir representing global debugging info directories (available
2543 via 'show debug-file-directory') and $datadir representing GDB's data
2544 directory (available via 'show data-directory').
2546 --with-auto-load-safe-path
2547 Configure default value for the 'set auto-load safe-path' setting
2548 above. It defaults to the --with-auto-load-dir setting.
2550 --without-auto-load-safe-path
2551 Set 'set auto-load safe-path' to '/', effectively disabling this
2554 * New remote packets
2556 z0/z1 conditional breakpoints extension
2558 The z0/z1 breakpoint insertion packets have been extended to carry
2559 a list of conditional expressions over to the remote stub depending on the
2560 condition evaluation mode. The use of this extension can be controlled
2561 via the "set remote conditional-breakpoints-packet" command.
2565 Specify the signals which the remote stub may pass to the debugged
2566 program without GDB involvement.
2568 * New command line options
2570 --init-command=FILE, -ix Like --command, -x but execute it
2571 before loading inferior.
2572 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2573 execute it before loading inferior.
2575 *** Changes in GDB 7.4
2577 * GDB now handles ambiguous linespecs more consistently; the existing
2578 FILE:LINE support has been expanded to other types of linespecs. A
2579 breakpoint will now be set on all matching locations in all
2580 inferiors, and locations will be added or removed according to
2583 * GDB now allows you to skip uninteresting functions and files when
2584 stepping with the "skip function" and "skip file" commands.
2586 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2587 and "show remote hardware-watchpoint-length-limit". These allows to
2588 set or show the maximum length limit (in bytes) of a remote
2589 target hardware watchpoint.
2591 This allows e.g. to use "unlimited" hardware watchpoints with the
2592 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2593 watchpoints are slower than real hardware watchpoints but are
2594 significantly faster than gdb software watchpoints.
2598 ** The register_pretty_printer function in module gdb.printing now takes
2599 an optional `replace' argument. If True, the new printer replaces any
2602 ** The "maint set python print-stack on|off" command has been
2603 deprecated and will be deleted in GDB 7.5.
2604 A new command: "set python print-stack none|full|message" has
2605 replaced it. Additionally, the default for "print-stack" is
2606 now "message", which just prints the error message without
2609 ** A prompt substitution hook (prompt_hook) is now available to the
2612 ** A new Python module, gdb.prompt has been added to the GDB Python
2613 modules library. This module provides functionality for
2614 escape sequences in prompts (used by set/show
2615 extended-prompt). These escape sequences are replaced by their
2616 corresponding value.
2618 ** Python commands and convenience-functions located in
2619 'data-directory'/python/gdb/command and
2620 'data-directory'/python/gdb/function are now automatically loaded
2623 ** Blocks now provide four new attributes. global_block and
2624 static_block will return the global and static blocks
2625 respectively. is_static and is_global are boolean attributes
2626 that indicate if the block is one of those two types.
2628 ** Symbols now provide the "type" attribute, the type of the symbol.
2630 ** The "gdb.breakpoint" function has been deprecated in favor of
2633 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2634 of a function. This class is based on the "finish" command
2635 available in the CLI.
2637 ** Type objects for struct and union types now allow access to
2638 the fields using standard Python dictionary (mapping) methods.
2639 For example, "some_type['myfield']" now works, as does
2640 "some_type.items()".
2642 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2645 ** A new function, "deep_items" has been added to the gdb.types
2646 module in the GDB Python modules library. This function returns
2647 an iterator over the fields of a struct or union type. Unlike
2648 the standard Python "iteritems" method, it will recursively traverse
2649 any anonymous fields.
2653 ** "*stopped" events can report several new "reason"s, such as
2656 ** Breakpoint changes are now notified using new async records, like
2657 "=breakpoint-modified".
2659 ** New command -ada-task-info.
2661 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2662 $sdir specifies the default system locations of shared libraries.
2663 $pdir specifies the directory where the libpthread used by the application
2666 GDB no longer looks in $sdir and $pdir after it has searched the directories
2667 mentioned in libthread-db-search-path. If you want to search those
2668 directories, they must be specified in libthread-db-search-path.
2669 The default value of libthread-db-search-path on GNU/Linux and Solaris
2670 systems is now "$sdir:$pdir".
2672 $pdir is not supported by gdbserver, it is currently ignored.
2673 $sdir is supported by gdbserver.
2675 * New configure option --with-iconv-bin.
2676 When using the internationalization support like the one in the GNU C
2677 library, GDB will invoke the "iconv" program to get a list of supported
2678 character sets. If this program lives in a non-standard location, one can
2679 use this option to specify where to find it.
2681 * When natively debugging programs on PowerPC BookE processors running
2682 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2683 watchpoints, which specify a mask in addition to an address to watch.
2684 The mask specifies that some bits of an address (the bits which are
2685 reset in the mask) should be ignored when matching the address accessed
2686 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2687 section in the user manual for more details.
2689 * The new option --once causes GDBserver to stop listening for connections once
2690 the first connection is made. The listening port used by GDBserver will
2691 become available after that.
2693 * New commands "info macros" and "alias" have been added.
2695 * New function parameters suffix @entry specifies value of function parameter
2696 at the time the function got called. Entry values are available only since
2702 "!" is now an alias of the "shell" command.
2703 Note that no space is needed between "!" and SHELL COMMAND.
2707 watch EXPRESSION mask MASK_VALUE
2708 The watch command now supports the mask argument which allows creation
2709 of masked watchpoints, if the current architecture supports this feature.
2711 info auto-load-scripts [REGEXP]
2712 This command was formerly named "maintenance print section-scripts".
2713 It is now generally useful and is no longer a maintenance-only command.
2715 info macro [-all] [--] MACRO
2716 The info macro command has new options `-all' and `--'. The first for
2717 printing all definitions of a macro. The second for explicitly specifying
2718 the end of arguments and the beginning of the macro name in case the macro
2719 name starts with a hyphen.
2721 collect[/s] EXPRESSIONS
2722 The tracepoint collect command now takes an optional modifier "/s"
2723 that directs it to dereference pointer-to-character types and
2724 collect the bytes of memory up to a zero byte. The behavior is
2725 similar to what you see when you use the regular print command on a
2726 string. An optional integer following the "/s" sets a bound on the
2727 number of bytes that will be collected.
2730 The trace start command now interprets any supplied arguments as a
2731 note to be recorded with the trace run, with an effect similar to
2732 setting the variable trace-notes.
2735 The trace stop command now interprets any arguments as a note to be
2736 mentioned along with the tstatus report that the trace was stopped
2737 with a command. The effect is similar to setting the variable
2740 * Tracepoints can now be enabled and disabled at any time after a trace
2741 experiment has been started using the standard "enable" and "disable"
2742 commands. It is now possible to start a trace experiment with no enabled
2743 tracepoints; GDB will display a warning, but will allow the experiment to
2744 begin, assuming that tracepoints will be enabled as needed while the trace
2747 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2748 locations with 4-byte instructions, when they were previously
2749 limited to locations with instructions of 5 bytes or longer.
2753 set debug dwarf2-read
2754 show debug dwarf2-read
2755 Turns on or off display of debugging messages related to reading
2756 DWARF debug info. The default is off.
2758 set debug symtab-create
2759 show debug symtab-create
2760 Turns on or off display of debugging messages related to symbol table
2761 creation. The default is off.
2764 show extended-prompt
2765 Set the GDB prompt, and allow escape sequences to be inserted to
2766 display miscellaneous information (see 'help set extended-prompt'
2767 for the list of sequences). This prompt (and any information
2768 accessed through the escape sequences) is updated every time the
2769 prompt is displayed.
2771 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2772 show print entry-values
2773 Set printing of frame argument values at function entry. In some cases
2774 GDB can determine the value of function argument which was passed by the
2775 function caller, even if the value was modified inside the called function.
2777 set debug entry-values
2778 show debug entry-values
2779 Control display of debugging info for determining frame argument values at
2780 function entry and virtual tail call frames.
2782 set basenames-may-differ
2783 show basenames-may-differ
2784 Set whether a source file may have multiple base names.
2785 (A "base name" is the name of a file with the directory part removed.
2786 Example: The base name of "/home/user/hello.c" is "hello.c".)
2787 If set, GDB will canonicalize file names (e.g., expand symlinks)
2788 before comparing them. Canonicalization is an expensive operation,
2789 but it allows the same file be known by more than one base name.
2790 If not set (the default), all source files are assumed to have just
2791 one base name, and gdb will do file name comparisons more efficiently.
2797 Set a user name and notes for the current and any future trace runs.
2798 This is useful for long-running and/or disconnected traces, to
2799 inform others (or yourself) as to who is running the trace, supply
2800 contact information, or otherwise explain what is going on.
2802 set trace-stop-notes
2803 show trace-stop-notes
2804 Set a note attached to the trace run, that is displayed when the
2805 trace has been stopped by a tstop command. This is useful for
2806 instance as an explanation, if you are stopping a trace run that was
2807 started by someone else.
2809 * New remote packets
2813 Dynamically enable a tracepoint in a started trace experiment.
2817 Dynamically disable a tracepoint in a started trace experiment.
2821 Set the user and notes of the trace run.
2825 Query the current status of a tracepoint.
2829 Query the minimum length of instruction at which a fast tracepoint may
2832 * Dcache size (number of lines) and line-size are now runtime-configurable
2833 via "set dcache line" and "set dcache line-size" commands.
2837 Texas Instruments TMS320C6x tic6x-*-*
2841 Renesas RL78 rl78-*-elf
2843 *** Changes in GDB 7.3.1
2845 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2847 *** Changes in GDB 7.3
2849 * GDB has a new command: "thread find [REGEXP]".
2850 It finds the thread id whose name, target id, or thread extra info
2851 matches the given regular expression.
2853 * The "catch syscall" command now works on mips*-linux* targets.
2855 * The -data-disassemble MI command now supports modes 2 and 3 for
2856 dumping the instruction opcodes.
2858 * New command line options
2860 -data-directory DIR Specify DIR as the "data-directory".
2861 This is mostly for testing purposes.
2863 * The "maint set python auto-load on|off" command has been renamed to
2864 "set auto-load-scripts on|off".
2866 * GDB has a new command: "set directories".
2867 It is like the "dir" command except that it replaces the
2868 source path list instead of augmenting it.
2870 * GDB now understands thread names.
2872 On GNU/Linux, "info threads" will display the thread name as set by
2873 prctl or pthread_setname_np.
2875 There is also a new command, "thread name", which can be used to
2876 assign a name internally for GDB to display.
2879 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2880 has been integrated into GDB.
2884 ** The function gdb.Write now accepts an optional keyword 'stream'.
2885 This keyword, when provided, will direct the output to either
2886 stdout, stderr, or GDB's logging output.
2888 ** Parameters can now be be sub-classed in Python, and in particular
2889 you may implement the get_set_doc and get_show_doc functions.
2890 This improves how Parameter set/show documentation is processed
2891 and allows for more dynamic content.
2893 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2894 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2895 have an is_valid method.
2897 ** Breakpoints can now be sub-classed in Python, and in particular
2898 you may implement a 'stop' function that is executed each time
2899 the inferior reaches that breakpoint.
2901 ** New function gdb.lookup_global_symbol looks up a global symbol.
2903 ** GDB values in Python are now callable if the value represents a
2904 function. For example, if 'some_value' represents a function that
2905 takes two integer parameters and returns a value, you can call
2906 that function like so:
2908 result = some_value (10,20)
2910 ** Module gdb.types has been added.
2911 It contains a collection of utilities for working with gdb.Types objects:
2912 get_basic_type, has_field, make_enum_dict.
2914 ** Module gdb.printing has been added.
2915 It contains utilities for writing and registering pretty-printers.
2916 New classes: PrettyPrinter, SubPrettyPrinter,
2917 RegexpCollectionPrettyPrinter.
2918 New function: register_pretty_printer.
2920 ** New commands "info pretty-printers", "enable pretty-printer" and
2921 "disable pretty-printer" have been added.
2923 ** gdb.parameter("directories") is now available.
2925 ** New function gdb.newest_frame returns the newest frame in the
2928 ** The gdb.InferiorThread class has a new "name" attribute. This
2929 holds the thread's name.
2931 ** Python Support for Inferior events.
2932 Python scripts can add observers to be notified of events
2933 occurring in the process being debugged.
2934 The following events are currently supported:
2935 - gdb.events.cont Continue event.
2936 - gdb.events.exited Inferior exited event.
2937 - gdb.events.stop Signal received, and Breakpoint hit events.
2941 ** GDB now puts template parameters in scope when debugging in an
2942 instantiation. For example, if you have:
2944 template<int X> int func (void) { return X; }
2946 then if you step into func<5>, "print X" will show "5". This
2947 feature requires proper debuginfo support from the compiler; it
2948 was added to GCC 4.5.
2950 ** The motion commands "next", "finish", "until", and "advance" now
2951 work better when exceptions are thrown. In particular, GDB will
2952 no longer lose control of the inferior; instead, the GDB will
2953 stop the inferior at the point at which the exception is caught.
2954 This functionality requires a change in the exception handling
2955 code that was introduced in GCC 4.5.
2957 * GDB now follows GCC's rules on accessing volatile objects when
2958 reading or writing target state during expression evaluation.
2959 One notable difference to prior behavior is that "print x = 0"
2960 no longer generates a read of x; the value of the assignment is
2961 now always taken directly from the value being assigned.
2963 * GDB now has some support for using labels in the program's source in
2964 linespecs. For instance, you can use "advance label" to continue
2965 execution to a label.
2967 * GDB now has support for reading and writing a new .gdb_index
2968 section. This section holds a fast index of DWARF debugging
2969 information and can be used to greatly speed up GDB startup and
2970 operation. See the documentation for `save gdb-index' for details.
2972 * The "watch" command now accepts an optional "-location" argument.
2973 When used, this causes GDB to watch the memory referred to by the
2974 expression. Such a watchpoint is never deleted due to it going out
2977 * GDB now supports thread debugging of core dumps on GNU/Linux.
2979 GDB now activates thread debugging using the libthread_db library
2980 when debugging GNU/Linux core dumps, similarly to when debugging
2981 live processes. As a result, when debugging a core dump file, GDB
2982 is now able to display pthread_t ids of threads. For example, "info
2983 threads" shows the same output as when debugging the process when it
2984 was live. In earlier releases, you'd see something like this:
2987 * 1 LWP 6780 main () at main.c:10
2989 While now you see this:
2992 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2994 It is also now possible to inspect TLS variables when debugging core
2997 When debugging a core dump generated on a machine other than the one
2998 used to run GDB, you may need to point GDB at the correct
2999 libthread_db library with the "set libthread-db-search-path"
3000 command. See the user manual for more details on this command.
3002 * When natively debugging programs on PowerPC BookE processors running
3003 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3004 which stop execution of the inferior whenever it executes an instruction
3005 at any address within the specified range. See the "PowerPC Embedded"
3006 section in the user manual for more details.
3008 * New features in the GDB remote stub, GDBserver
3010 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3011 and i686 LynxOS (version 5.x).
3013 ** GDBserver is now supported on Blackfin Linux.
3015 * New native configurations
3017 ia64 HP-UX ia64-*-hpux*
3021 Analog Devices, Inc. Blackfin Processor bfin-*
3023 * Ada task switching is now supported on sparc-elf targets when
3024 debugging a program using the Ravenscar Profile. For more information,
3025 see the "Tasking Support when using the Ravenscar Profile" section
3026 in the GDB user manual.
3028 * Guile support was removed.
3030 * New features in the GNU simulator
3032 ** The --map-info flag lists all known core mappings.
3034 ** CFI flashes may be simulated via the "cfi" device.
3036 *** Changes in GDB 7.2
3038 * Shared library support for remote targets by default
3040 When GDB is configured for a generic, non-OS specific target, like
3041 for example, --target=arm-eabi or one of the many *-*-elf targets,
3042 GDB now queries remote stubs for loaded shared libraries using the
3043 `qXfer:libraries:read' packet. Previously, shared library support
3044 was always disabled for such configurations.
3048 ** Argument Dependent Lookup (ADL)
3050 In C++ ADL lookup directs function search to the namespaces of its
3051 arguments even if the namespace has not been imported.
3061 Here the compiler will search for `foo' in the namespace of 'b'
3062 and find A::foo. GDB now supports this. This construct is commonly
3063 used in the Standard Template Library for operators.
3065 ** Improved User Defined Operator Support
3067 In addition to member operators, GDB now supports lookup of operators
3068 defined in a namespace and imported with a `using' directive, operators
3069 defined in the global scope, operators imported implicitly from an
3070 anonymous namespace, and the ADL operators mentioned in the previous
3072 GDB now also supports proper overload resolution for all the previously
3073 mentioned flavors of operators.
3075 ** static const class members
3077 Printing of static const class members that are initialized in the
3078 class definition has been fixed.
3080 * Windows Thread Information Block access.
3082 On Windows targets, GDB now supports displaying the Windows Thread
3083 Information Block (TIB) structure. This structure is visible either
3084 by using the new command `info w32 thread-information-block' or, by
3085 dereferencing the new convenience variable named `$_tlb', a
3086 thread-specific pointer to the TIB. This feature is also supported
3087 when remote debugging using GDBserver.
3089 * Static tracepoints
3091 Static tracepoints are calls in the user program into a tracing
3092 library. One such library is a port of the LTTng kernel tracer to
3093 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3094 When debugging with GDBserver, GDB now supports combining the GDB
3095 tracepoint machinery with such libraries. For example: the user can
3096 use GDB to probe a static tracepoint marker (a call from the user
3097 program into the tracing library) with the new "strace" command (see
3098 "New commands" below). This creates a "static tracepoint" in the
3099 breakpoint list, that can be manipulated with the same feature set
3100 as fast and regular tracepoints. E.g., collect registers, local and
3101 global variables, collect trace state variables, and define
3102 tracepoint conditions. In addition, the user can collect extra
3103 static tracepoint marker specific data, by collecting the new
3104 $_sdata internal variable. When analyzing the trace buffer, you can
3105 inspect $_sdata like any other variable available to GDB. For more
3106 information, see the "Tracepoints" chapter in GDB user manual. New
3107 remote packets have been defined to support static tracepoints, see
3108 the "New remote packets" section below.
3110 * Better reconstruction of tracepoints after disconnected tracing
3112 GDB will attempt to download the original source form of tracepoint
3113 definitions when starting a trace run, and then will upload these
3114 upon reconnection to the target, resulting in a more accurate
3115 reconstruction of the tracepoints that are in use on the target.
3119 You can now exercise direct control over the ways that GDB can
3120 affect your program. For instance, you can disallow the setting of
3121 breakpoints, so that the program can run continuously (assuming
3122 non-stop mode). In addition, the "observer" variable is available
3123 to switch all of the different controls; in observer mode, GDB
3124 cannot affect the target's behavior at all, which is useful for
3125 tasks like diagnosing live systems in the field.
3127 * The new convenience variable $_thread holds the number of the
3130 * New remote packets
3134 Return the address of the Windows Thread Information Block of a given thread.
3138 In response to several of the tracepoint packets, the target may now
3139 also respond with a number of intermediate `qRelocInsn' request
3140 packets before the final result packet, to have GDB handle
3141 relocating an instruction to execute at a different address. This
3142 is particularly useful for stubs that support fast tracepoints. GDB
3143 reports support for this feature in the qSupported packet.
3147 List static tracepoint markers in the target program.
3151 List static tracepoint markers at a given address in the target
3154 qXfer:statictrace:read
3156 Read the static trace data collected (by a `collect $_sdata'
3157 tracepoint action). The remote stub reports support for this packet
3158 to gdb's qSupported query.
3162 Send the current settings of GDB's permission flags.
3166 Send part of the source (textual) form of a tracepoint definition,
3167 which includes location, conditional, and action list.
3169 * The source command now accepts a -s option to force searching for the
3170 script in the source search path even if the script name specifies
3173 * New features in the GDB remote stub, GDBserver
3175 - GDBserver now support tracepoints (including fast tracepoints, and
3176 static tracepoints). The feature is currently supported by the
3177 i386-linux and amd64-linux builds. See the "Tracepoints support
3178 in gdbserver" section in the manual for more information.
3180 GDBserver JIT compiles the tracepoint's conditional agent
3181 expression bytecode into native code whenever possible for low
3182 overhead dynamic tracepoints conditionals. For such tracepoints,
3183 an expression that examines program state is evaluated when the
3184 tracepoint is reached, in order to determine whether to capture
3185 trace data. If the condition is simple and false, processing the
3186 tracepoint finishes very quickly and no data is gathered.
3188 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3189 for static tracepoints support.
3191 - GDBserver now supports x86_64 Windows 64-bit debugging.
3193 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3194 it understands register description.
3196 * The --batch flag now disables pagination and queries.
3198 * X86 general purpose registers
3200 GDB now supports reading/writing byte, word and double-word x86
3201 general purpose registers directly. This means you can use, say,
3202 $ah or $ax to refer, respectively, to the byte register AH and
3203 16-bit word register AX that are actually portions of the 32-bit
3204 register EAX or 64-bit register RAX.
3206 * The `commands' command now accepts a range of breakpoints to modify.
3207 A plain `commands' following a command that creates multiple
3208 breakpoints affects all the breakpoints set by that command. This
3209 applies to breakpoints set by `rbreak', and also applies when a
3210 single `break' command creates multiple breakpoints (e.g.,
3211 breakpoints on overloaded c++ functions).
3213 * The `rbreak' command now accepts a filename specification as part of
3214 its argument, limiting the functions selected by the regex to those
3215 in the specified file.
3217 * Support for remote debugging Windows and SymbianOS shared libraries
3218 from Unix hosts has been improved. Non Windows GDB builds now can
3219 understand target reported file names that follow MS-DOS based file
3220 system semantics, such as file names that include drive letters and
3221 use the backslash character as directory separator. This makes it
3222 possible to transparently use the "set sysroot" and "set
3223 solib-search-path" on Unix hosts to point as host copies of the
3224 target's shared libraries. See the new command "set
3225 target-file-system-kind" described below, and the "Commands to
3226 specify files" section in the user manual for more information.
3230 eval template, expressions...
3231 Convert the values of one or more expressions under the control
3232 of the string template to a command line, and call it.
3234 set target-file-system-kind unix|dos-based|auto
3235 show target-file-system-kind
3236 Set or show the assumed file system kind for target reported file
3239 save breakpoints <filename>
3240 Save all current breakpoint definitions to a file suitable for use
3241 in a later debugging session. To read the saved breakpoint
3242 definitions, use the `source' command.
3244 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3247 info static-tracepoint-markers
3248 Display information about static tracepoint markers in the target.
3250 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3251 Define a static tracepoint by probing a marker at the given
3252 function, line, address, or marker ID.
3256 Enable and disable observer mode.
3258 set may-write-registers on|off
3259 set may-write-memory on|off
3260 set may-insert-breakpoints on|off
3261 set may-insert-tracepoints on|off
3262 set may-insert-fast-tracepoints on|off
3263 set may-interrupt on|off
3264 Set individual permissions for GDB effects on the target. Note that
3265 some of these settings can have undesirable or surprising
3266 consequences, particularly when changed in the middle of a session.
3267 For instance, disabling the writing of memory can prevent
3268 breakpoints from being inserted, cause single-stepping to fail, or
3269 even crash your program, if you disable after breakpoints have been
3270 inserted. However, GDB should not crash.
3272 set record memory-query on|off
3273 show record memory-query
3274 Control whether to stop the inferior if memory changes caused
3275 by an instruction cannot be recorded.
3280 The disassemble command now supports "start,+length" form of two arguments.
3284 ** GDB now provides a new directory location, called the python directory,
3285 where Python scripts written for GDB can be installed. The location
3286 of that directory is <data-directory>/python, where <data-directory>
3287 is the GDB data directory. For more details, see section `Scripting
3288 GDB using Python' in the manual.
3290 ** The GDB Python API now has access to breakpoints, symbols, symbol
3291 tables, program spaces, inferiors, threads and frame's code blocks.
3292 Additionally, GDB Parameters can now be created from the API, and
3293 manipulated via set/show in the CLI.
3295 ** New functions gdb.target_charset, gdb.target_wide_charset,
3296 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3298 ** New exception gdb.GdbError.
3300 ** Pretty-printers are now also looked up in the current program space.
3302 ** Pretty-printers can now be individually enabled and disabled.
3304 ** GDB now looks for names of Python scripts to auto-load in a
3305 special section named `.debug_gdb_scripts', in addition to looking
3306 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3308 * Tracepoint actions were unified with breakpoint commands. In particular,
3309 there are no longer differences in "info break" output for breakpoints and
3310 tracepoints and the "commands" command can be used for both tracepoints and
3311 regular breakpoints.
3315 ARM Symbian arm*-*-symbianelf*
3317 * D language support.
3318 GDB now supports debugging programs written in the D programming
3321 * GDB now supports the extended ptrace interface for PowerPC which is
3322 available since Linux kernel version 2.6.34. This automatically enables
3323 any hardware breakpoints and additional hardware watchpoints available in
3324 the processor. The old ptrace interface exposes just one hardware
3325 watchpoint and no hardware breakpoints.
3327 * GDB is now able to use the Data Value Compare (DVC) register available on
3328 embedded PowerPC processors to implement in hardware simple watchpoint
3329 conditions of the form:
3331 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3333 This works in native GDB running on Linux kernels with the extended ptrace
3334 interface mentioned above.
3336 *** Changes in GDB 7.1
3340 ** Namespace Support
3342 GDB now supports importing of namespaces in C++. This enables the
3343 user to inspect variables from imported namespaces. Support for
3344 namepace aliasing has also been added. So, if a namespace is
3345 aliased in the current scope (e.g. namepace C=A; ) the user can
3346 print variables using the alias (e.g. (gdb) print C::x).
3350 All known bugs relating to the printing of virtual base class were
3351 fixed. It is now possible to call overloaded static methods using a
3356 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3357 and reinterpret_cast<> are now handled by the C++ expression parser.
3361 Xilinx MicroBlaze microblaze-*-*
3366 Xilinx MicroBlaze microblaze
3369 * Multi-program debugging.
3371 GDB now has support for multi-program (a.k.a. multi-executable or
3372 multi-exec) debugging. This allows for debugging multiple inferiors
3373 simultaneously each running a different program under the same GDB
3374 session. See "Debugging Multiple Inferiors and Programs" in the
3375 manual for more information. This implied some user visible changes
3376 in the multi-inferior support. For example, "info inferiors" now
3377 lists inferiors that are not running yet or that have exited
3378 already. See also "New commands" and "New options" below.
3380 * New tracing features
3382 GDB's tracepoint facility now includes several new features:
3384 ** Trace state variables
3386 GDB tracepoints now include support for trace state variables, which
3387 are variables managed by the target agent during a tracing
3388 experiment. They are useful for tracepoints that trigger each
3389 other, so for instance one tracepoint can count hits in a variable,
3390 and then a second tracepoint has a condition that is true when the
3391 count reaches a particular value. Trace state variables share the
3392 $-syntax of GDB convenience variables, and can appear in both
3393 tracepoint actions and condition expressions. Use the "tvariable"
3394 command to create, and "info tvariables" to view; see "Trace State
3395 Variables" in the manual for more detail.
3399 GDB now includes an option for defining fast tracepoints, which
3400 targets may implement more efficiently, such as by installing a jump
3401 into the target agent rather than a trap instruction. The resulting
3402 speedup can be by two orders of magnitude or more, although the
3403 tradeoff is that some program locations on some target architectures
3404 might not allow fast tracepoint installation, for instance if the
3405 instruction to be replaced is shorter than the jump. To request a
3406 fast tracepoint, use the "ftrace" command, with syntax identical to
3407 the regular trace command.
3409 ** Disconnected tracing
3411 It is now possible to detach GDB from the target while it is running
3412 a trace experiment, then reconnect later to see how the experiment
3413 is going. In addition, a new variable disconnected-tracing lets you
3414 tell the target agent whether to continue running a trace if the
3415 connection is lost unexpectedly.
3419 GDB now has the ability to save the trace buffer into a file, and
3420 then use that file as a target, similarly to you can do with
3421 corefiles. You can select trace frames, print data that was
3422 collected in them, and use tstatus to display the state of the
3423 tracing run at the moment that it was saved. To create a trace
3424 file, use "tsave <filename>", and to use it, do "target tfile
3427 ** Circular trace buffer
3429 You can ask the target agent to handle the trace buffer as a
3430 circular buffer, discarding the oldest trace frames to make room for
3431 newer ones, by setting circular-trace-buffer to on. This feature may
3432 not be available for all target agents.
3437 The disassemble command, when invoked with two arguments, now requires
3438 the arguments to be comma-separated.
3441 The info variables command now displays variable definitions. Files
3442 which only declare a variable are not shown.
3445 The source command is now capable of sourcing Python scripts.
3446 This feature is dependent on the debugger being build with Python
3449 Related to this enhancement is also the introduction of a new command
3450 "set script-extension" (see below).
3452 * New commands (for set/show, see "New options" below)
3454 record save [<FILENAME>]
3455 Save a file (in core file format) containing the process record
3456 execution log for replay debugging at a later time.
3458 record restore <FILENAME>
3459 Restore the process record execution log that was saved at an
3460 earlier time, for replay debugging.
3462 add-inferior [-copies <N>] [-exec <FILENAME>]
3465 clone-inferior [-copies <N>] [ID]
3466 Make a new inferior ready to execute the same program another
3467 inferior has loaded.
3472 maint info program-spaces
3473 List the program spaces loaded into GDB.
3475 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3476 show remote interrupt-sequence
3477 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3478 as the sequence to the remote target in order to interrupt the execution.
3479 Ctrl-C is a default. Some system prefers BREAK which is high level of
3480 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3481 Magic SysRq g. It is BREAK signal and character 'g'.
3483 set remote interrupt-on-connect [on | off]
3484 show remote interrupt-on-connect
3485 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3486 remote target when gdb connects to it. This is needed when you debug
3489 set remotebreak [on | off]
3491 Deprecated. Use "set/show remote interrupt-sequence" instead.
3493 tvariable $NAME [ = EXP ]
3494 Create or modify a trace state variable.
3497 List trace state variables and their values.
3499 delete tvariable $NAME ...
3500 Delete one or more trace state variables.
3503 Evaluate the given expressions without collecting anything into the
3504 trace buffer. (Valid in tracepoint actions only.)
3506 ftrace FN / FILE:LINE / *ADDR
3507 Define a fast tracepoint at the given function, line, or address.
3509 * New expression syntax
3511 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3512 GDB now parses 0b101010 identically with 42.
3516 set follow-exec-mode new|same
3517 show follow-exec-mode
3518 Control whether GDB reuses the same inferior across an exec call or
3519 creates a new one. This is useful to be able to restart the old
3520 executable after the inferior having done an exec call.
3522 set default-collect EXPR, ...
3523 show default-collect
3524 Define a list of expressions to be collected at each tracepoint.
3525 This is a useful way to ensure essential items are not overlooked,
3526 such as registers or a critical global variable.
3528 set disconnected-tracing
3529 show disconnected-tracing
3530 If set to 1, the target is instructed to continue tracing if it
3531 loses its connection to GDB. If 0, the target is to stop tracing
3534 set circular-trace-buffer
3535 show circular-trace-buffer
3536 If set to on, the target is instructed to use a circular trace buffer
3537 and discard the oldest trace frames instead of stopping the trace due
3538 to a full trace buffer. If set to off, the trace stops when the buffer
3539 fills up. Some targets may not support this.
3541 set script-extension off|soft|strict
3542 show script-extension
3543 If set to "off", the debugger does not perform any script language
3544 recognition, and all sourced files are assumed to be GDB scripts.
3545 If set to "soft" (the default), files are sourced according to
3546 filename extension, falling back to GDB scripts if the first
3548 If set to "strict", files are sourced according to filename extension.
3550 set ada trust-PAD-over-XVS on|off
3551 show ada trust-PAD-over-XVS
3552 If off, activate a workaround against a bug in the debugging information
3553 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3554 the GCC sources for more information about the GNAT encoding and
3555 PAD types in particular). It is always safe to set this option to
3556 off, but this introduces a slight performance penalty. The default
3559 * Python API Improvements
3561 ** GDB provides the new class gdb.LazyString. This is useful in
3562 some pretty-printing cases. The new method gdb.Value.lazy_string
3563 provides a simple way to create objects of this type.
3565 ** The fields returned by gdb.Type.fields now have an
3566 `is_base_class' attribute.
3568 ** The new method gdb.Type.range returns the range of an array type.
3570 ** The new method gdb.parse_and_eval can be used to parse and
3571 evaluate an expression.
3573 * New remote packets
3576 Define a trace state variable.
3579 Get the current value of a trace state variable.
3582 Set desired tracing behavior upon disconnection.
3585 Set the trace buffer to be linear or circular.
3588 Get data about the tracepoints currently in use.
3592 Process record now works correctly with hardware watchpoints.
3594 Multiple bug fixes have been made to the mips-irix port, making it
3595 much more reliable. In particular:
3596 - Debugging threaded applications is now possible again. Previously,
3597 GDB would hang while starting the program, or while waiting for
3598 the program to stop at a breakpoint.
3599 - Attaching to a running process no longer hangs.
3600 - An error occurring while loading a core file has been fixed.
3601 - Changing the value of the PC register now works again. This fixes
3602 problems observed when using the "jump" command, or when calling
3603 a function from GDB, or even when assigning a new value to $pc.
3604 - With the "finish" and "return" commands, the return value for functions
3605 returning a small array is now correctly printed.
3606 - It is now possible to break on shared library code which gets executed
3607 during a shared library init phase (code executed while executing
3608 their .init section). Previously, the breakpoint would have no effect.
3609 - GDB is now able to backtrace through the signal handler for
3610 non-threaded programs.
3612 PIE (Position Independent Executable) programs debugging is now supported.
3613 This includes debugging execution of PIC (Position Independent Code) shared
3614 libraries although for that, it should be possible to run such libraries as an
3617 *** Changes in GDB 7.0
3619 * GDB now has an interface for JIT compilation. Applications that
3620 dynamically generate code can create symbol files in memory and register
3621 them with GDB. For users, the feature should work transparently, and
3622 for JIT developers, the interface is documented in the GDB manual in the
3623 "JIT Compilation Interface" chapter.
3625 * Tracepoints may now be conditional. The syntax is as for
3626 breakpoints; either an "if" clause appended to the "trace" command,
3627 or the "condition" command is available. GDB sends the condition to
3628 the target for evaluation using the same bytecode format as is used
3629 for tracepoint actions.
3631 * The disassemble command now supports: an optional /r modifier, print the
3632 raw instructions in hex as well as in symbolic form, and an optional /m
3633 modifier to print mixed source+assembly.
3635 * Process record and replay
3637 In a architecture environment that supports ``process record and
3638 replay'', ``process record and replay'' target can record a log of
3639 the process execution, and replay it with both forward and reverse
3642 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3643 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3644 set execution-direction {forward|reverse}, for targets that support
3647 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3648 feature is available with a native GDB running on kernel version
3651 * GDB now has support for multi-byte and wide character sets on the
3652 target. Strings whose character type is wchar_t, char16_t, or
3653 char32_t are now correctly printed. GDB supports wide- and unicode-
3654 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3655 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3656 `printf'. This feature requires iconv to work properly; if your
3657 system does not have a working iconv, GDB can use GNU libiconv. See
3658 the installation instructions for more information.
3660 * GDB now supports automatic retrieval of shared library files from
3661 remote targets. To use this feature, specify a system root that begins
3662 with the `remote:' prefix, either via the `set sysroot' command or via
3663 the `--with-sysroot' configure-time option.
3665 * "info sharedlibrary" now takes an optional regex of libraries to show,
3666 and it now reports if a shared library has no debugging information.
3668 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3669 now complete on file names.
3671 * When completing in expressions, gdb will attempt to limit
3672 completions to allowable structure or union fields, where appropriate.
3673 For instance, consider:
3675 # struct example { int f1; double f2; };
3676 # struct example variable;
3679 If the user types TAB at the end of this command line, the available
3680 completions will be "f1" and "f2".
3682 * Inlined functions are now supported. They show up in backtraces, and
3683 the "step", "next", and "finish" commands handle them automatically.
3685 * GDB now supports the token-splicing (##) and stringification (#)
3686 operators when expanding macros. It also supports variable-arity
3689 * GDB now supports inspecting extra signal information, exported by
3690 the new $_siginfo convenience variable. The feature is currently
3691 implemented on linux ARM, i386 and amd64.
3693 * GDB can now display the VFP floating point registers and NEON vector
3694 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3695 can provide these registers (requires Linux 2.6.30 or later). Remote
3696 and simulator targets may also provide them.
3698 * New remote packets
3701 Search memory for a sequence of bytes.
3704 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3705 operation over reliable transport links. Use of this packet is
3706 controlled by the `set remote noack-packet' command.
3709 Kill the process with the specified process ID. Use this in preference
3710 to `k' when multiprocess protocol extensions are supported.
3713 Obtains additional operating system information
3717 Read or write additional signal information.
3719 * Removed remote protocol undocumented extension
3721 An undocumented extension to the remote protocol's `S' stop reply
3722 packet that permited the stub to pass a process id was removed.
3723 Remote servers should use the `T' stop reply packet instead.
3725 * GDB now supports multiple function calling conventions according to the
3726 DWARF-2 DW_AT_calling_convention function attribute.
3728 * The SH target utilizes the aforementioned change to distinguish between gcc
3729 and Renesas calling convention. It also adds the new CLI commands
3730 `set/show sh calling-convention'.
3732 * GDB can now read compressed debug sections, as produced by GNU gold
3733 with the --compress-debug-sections=zlib flag.
3735 * 64-bit core files are now supported on AIX.
3737 * Thread switching is now supported on Tru64.
3739 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3740 which will be allocated using malloc later in program execution.
3742 * The qXfer:libraries:read remote procotol packet now allows passing a
3743 list of section offsets.
3745 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3746 conditions handling signals delivered during attach or thread creation
3747 have also been fixed.
3749 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3750 From the user's standpoint, all unqualified instances of True and False
3751 are treated as the standard definitions, regardless of context.
3753 * GDB now parses C++ symbol and type names more flexibly. For
3756 template<typename T> class C { };
3759 GDB will now correctly handle all of:
3761 ptype C<char const *>
3762 ptype C<char const*>
3763 ptype C<const char *>
3764 ptype C<const char*>
3766 * New features in the GDB remote stub, gdbserver
3768 - The "--wrapper" command-line argument tells gdbserver to use a
3769 wrapper program to launch programs for debugging.
3771 - On PowerPC and S/390 targets, it is now possible to use a single
3772 gdbserver executable to debug both 32-bit and 64-bit programs.
3773 (This requires gdbserver itself to be built as a 64-bit executable.)
3775 - gdbserver uses the new noack protocol mode for TCP connections to
3776 reduce communications latency, if also supported and enabled in GDB.
3778 - Support for the sparc64-linux-gnu target is now included in
3781 - The amd64-linux build of gdbserver now supports debugging both
3782 32-bit and 64-bit programs.
3784 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3785 now support hardware watchpoints, and will use them automatically
3790 GDB now has support for scripting using Python. Whether this is
3791 available is determined at configure time.
3793 New GDB commands can now be written in Python.
3795 * Ada tasking support
3797 Ada tasks can now be inspected in GDB. The following commands have
3801 Print the list of Ada tasks.
3803 Print detailed information about task number N.
3805 Print the task number of the current task.
3807 Switch the context of debugging to task number N.
3809 * Support for user-defined prefixed commands. The "define" command can
3810 add new commands to existing prefixes, e.g. "target".
3812 * Multi-inferior, multi-process debugging.
3814 GDB now has generalized support for multi-inferior debugging. See
3815 "Debugging Multiple Inferiors" in the manual for more information.
3816 Although availability still depends on target support, the command
3817 set is more uniform now. The GNU/Linux specific multi-forks support
3818 has been migrated to this new framework. This implied some user
3819 visible changes; see "New commands" and also "Removed commands"
3822 * Target descriptions can now describe the target OS ABI. See the
3823 "Target Description Format" section in the user manual for more
3826 * Target descriptions can now describe "compatible" architectures
3827 to indicate that the target can execute applications for a different
3828 architecture in addition to those for the main target architecture.
3829 See the "Target Description Format" section in the user manual for
3832 * Multi-architecture debugging.
3834 GDB now includes general supports for debugging applications on
3835 hybrid systems that use more than one single processor architecture
3836 at the same time. Each such hybrid architecture still requires
3837 specific support to be added. The only hybrid architecture supported
3838 in this version of GDB is the Cell Broadband Engine.
3840 * GDB now supports integrated debugging of Cell/B.E. applications that
3841 use both the PPU and SPU architectures. To enable support for hybrid
3842 Cell/B.E. debugging, you need to configure GDB to support both the
3843 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3844 --enable-targets configure option.
3846 * Non-stop mode debugging.
3848 For some targets, GDB now supports an optional mode of operation in
3849 which you can examine stopped threads while other threads continue
3850 to execute freely. This is referred to as non-stop mode, with the
3851 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3852 section in the user manual for more information.
3854 To be able to support remote non-stop debugging, a remote stub needs
3855 to implement the non-stop mode remote protocol extensions, as
3856 described in the "Remote Non-Stop" section of the user manual. The
3857 GDB remote stub, gdbserver, has been adjusted to support these
3858 extensions on linux targets.
3860 * New commands (for set/show, see "New options" below)
3862 catch syscall [NAME(S) | NUMBER(S)]
3863 Catch system calls. Arguments, which should be names of system
3864 calls or their numbers, mean catch only those syscalls. Without
3865 arguments, every syscall will be caught. When the inferior issues
3866 any of the specified syscalls, GDB will stop and announce the system
3867 call, both when it is called and when its call returns. This
3868 feature is currently available with a native GDB running on the
3869 Linux Kernel, under the following architectures: x86, x86_64,
3870 PowerPC and PowerPC64.
3872 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3874 Search memory for a sequence of bytes.
3876 maint set python print-stack
3877 maint show python print-stack
3878 Show a stack trace when an error is encountered in a Python script.
3881 Invoke CODE by passing it to the Python interpreter.
3886 These allow macros to be defined, undefined, and listed
3890 Show operating system information about processes.
3893 List the inferiors currently under GDB's control.
3896 Switch focus to inferior number NUM.
3899 Detach from inferior number NUM.
3902 Kill inferior number NUM.
3906 set spu stop-on-load
3907 show spu stop-on-load
3908 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3910 set spu auto-flush-cache
3911 show spu auto-flush-cache
3912 Control whether to automatically flush the software-managed cache
3913 during Cell/B.E. debugging.
3915 set sh calling-convention
3916 show sh calling-convention
3917 Control the calling convention used when calling SH target functions.
3920 show debug timestamp
3921 Control display of timestamps with GDB debugging output.
3923 set disassemble-next-line
3924 show disassemble-next-line
3925 Control display of disassembled source lines or instructions when
3928 set remote noack-packet
3929 show remote noack-packet
3930 Set/show the use of remote protocol QStartNoAckMode packet. See above
3931 under "New remote packets."
3933 set remote query-attached-packet
3934 show remote query-attached-packet
3935 Control use of remote protocol `qAttached' (query-attached) packet.
3937 set remote read-siginfo-object
3938 show remote read-siginfo-object
3939 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3942 set remote write-siginfo-object
3943 show remote write-siginfo-object
3944 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3947 set remote reverse-continue
3948 show remote reverse-continue
3949 Control use of remote protocol 'bc' (reverse-continue) packet.
3951 set remote reverse-step
3952 show remote reverse-step
3953 Control use of remote protocol 'bs' (reverse-step) packet.
3955 set displaced-stepping
3956 show displaced-stepping
3957 Control displaced stepping mode. Displaced stepping is a way to
3958 single-step over breakpoints without removing them from the debuggee.
3959 Also known as "out-of-line single-stepping".
3962 show debug displaced
3963 Control display of debugging info for displaced stepping.
3965 maint set internal-error
3966 maint show internal-error
3967 Control what GDB does when an internal error is detected.
3969 maint set internal-warning
3970 maint show internal-warning
3971 Control what GDB does when an internal warning is detected.
3976 Use a wrapper program to launch programs for debugging.
3978 set multiple-symbols (all|ask|cancel)
3979 show multiple-symbols
3980 The value of this variable can be changed to adjust the debugger behavior
3981 when an expression or a breakpoint location contains an ambiguous symbol
3982 name (an overloaded function name, for instance).
3984 set breakpoint always-inserted
3985 show breakpoint always-inserted
3986 Keep breakpoints always inserted in the target, as opposed to inserting
3987 them when resuming the target, and removing them when the target stops.
3988 This option can improve debugger performance on slow remote targets.
3990 set arm fallback-mode (arm|thumb|auto)
3991 show arm fallback-mode
3992 set arm force-mode (arm|thumb|auto)
3994 These commands control how ARM GDB determines whether instructions
3995 are ARM or Thumb. The default for both settings is auto, which uses
3996 the current CPSR value for instructions without symbols; previous
3997 versions of GDB behaved as if "set arm fallback-mode arm".
3999 set disable-randomization
4000 show disable-randomization
4001 Standalone programs run with the virtual address space randomization enabled
4002 by default on some platforms. This option keeps the addresses stable across
4003 multiple debugging sessions.
4007 Control whether other threads are stopped or not when some thread hits
4012 Requests that asynchronous execution is enabled in the target, if available.
4013 In this case, it's possible to resume target in the background, and interact
4014 with GDB while the target is running. "show target-async" displays the
4015 current state of asynchronous execution of the target.
4017 set target-wide-charset
4018 show target-wide-charset
4019 The target-wide-charset is the name of the character set that GDB
4020 uses when printing characters whose type is wchar_t.
4022 set tcp auto-retry (on|off)
4024 set tcp connect-timeout
4025 show tcp connect-timeout
4026 These commands allow GDB to retry failed TCP connections to a remote stub
4027 with a specified timeout period; this is useful if the stub is launched
4028 in parallel with GDB but may not be ready to accept connections immediately.
4030 set libthread-db-search-path
4031 show libthread-db-search-path
4032 Control list of directories which GDB will search for appropriate
4035 set schedule-multiple (on|off)
4036 show schedule-multiple
4037 Allow GDB to resume all threads of all processes or only threads of
4038 the current process.
4042 Use more aggressive caching for accesses to the stack. This improves
4043 performance of remote debugging (particularly backtraces) without
4044 affecting correctness.
4046 set interactive-mode (on|off|auto)
4047 show interactive-mode
4048 Control whether GDB runs in interactive mode (on) or not (off).
4049 When in interactive mode, GDB waits for the user to answer all
4050 queries. Otherwise, GDB does not wait and assumes the default
4051 answer. When set to auto (the default), GDB determines which
4052 mode to use based on the stdin settings.
4057 For program forks, this is replaced by the new more generic `info
4058 inferiors' command. To list checkpoints, you can still use the
4059 `info checkpoints' command, which was an alias for the `info forks'
4063 Replaced by the new `inferior' command. To switch between
4064 checkpoints, you can still use the `restart' command, which was an
4065 alias for the `fork' command.
4068 This is removed, since some targets don't have a notion of
4069 processes. To switch between processes, you can still use the
4070 `inferior' command using GDB's own inferior number.
4073 For program forks, this is replaced by the new more generic `kill
4074 inferior' command. To delete a checkpoint, you can still use the
4075 `delete checkpoint' command, which was an alias for the `delete
4079 For program forks, this is replaced by the new more generic `detach
4080 inferior' command. To detach a checkpoint, you can still use the
4081 `detach checkpoint' command, which was an alias for the `detach
4084 * New native configurations
4086 x86/x86_64 Darwin i[34567]86-*-darwin*
4088 x86_64 MinGW x86_64-*-mingw*
4092 Lattice Mico32 lm32-*
4093 x86 DICOS i[34567]86-*-dicos*
4094 x86_64 DICOS x86_64-*-dicos*
4097 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4098 (mingw32ce) debugging.
4104 These commands were actually not implemented on any target.
4106 *** Changes in GDB 6.8
4108 * New native configurations
4110 NetBSD/hppa hppa*-*netbsd*
4111 Xtensa GNU/Linux xtensa*-*-linux*
4115 NetBSD/hppa hppa*-*-netbsd*
4116 Xtensa GNU/Lunux xtensa*-*-linux*
4118 * Change in command line behavior -- corefiles vs. process ids.
4120 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4121 attaching to process NUMBER fails, GDB no longer attempts to open a
4122 core file named NUMBER. Attaching to a program using the -c option
4123 is no longer supported. Instead, use the '-p' or '--pid' options.
4125 * GDB can now be built as a native debugger for debugging Windows x86
4126 (mingw32) Portable Executable (PE) programs.
4128 * Pending breakpoints no longer change their number when their address
4131 * GDB now supports breakpoints with multiple locations,
4132 including breakpoints on C++ constructors, inside C++ templates,
4133 and in inlined functions.
4135 * GDB's ability to debug optimized code has been improved. GDB more
4136 accurately identifies function bodies and lexical blocks that occupy
4137 more than one contiguous range of addresses.
4139 * Target descriptions can now describe registers for PowerPC.
4141 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4142 registers on PowerPC targets.
4144 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4145 targets even when the libthread_db library is not available.
4147 * The GDB remote stub, gdbserver, now supports the new file transfer
4148 commands (remote put, remote get, and remote delete).
4150 * The GDB remote stub, gdbserver, now supports run and attach in
4151 extended-remote mode.
4153 * hppa*64*-*-hpux11* target broken
4154 The debugger is unable to start a program and fails with the following
4155 error: "Error trying to get information about dynamic linker".
4156 The gdb-6.7 release is also affected.
4158 * GDB now supports the --enable-targets= configure option to allow
4159 building a single GDB executable that supports multiple remote
4160 target architectures.
4162 * GDB now supports debugging C and C++ programs which use the
4163 Decimal Floating Point extension. In addition, the PowerPC target
4164 now has a set of pseudo-registers to inspect decimal float values
4165 stored in two consecutive float registers.
4167 * The -break-insert MI command can optionally create pending
4170 * Improved support for debugging Ada
4171 Many improvements to the Ada language support have been made. These
4173 - Better support for Ada2005 interface types
4174 - Improved handling of arrays and slices in general
4175 - Better support for Taft-amendment types
4176 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4178 - Improved command completion in Ada
4181 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4186 set print frame-arguments (all|scalars|none)
4187 show print frame-arguments
4188 The value of this variable can be changed to control which argument
4189 values should be printed by the debugger when displaying a frame.
4194 Transfer files to and from a remote target, and delete remote files.
4201 Transfer files to and from a remote target, and delete remote files.
4203 * New remote packets
4210 Open, close, read, write, and delete files on the remote system.
4213 Attach to an existing process on the remote system, in extended-remote
4217 Run a new process on the remote system, in extended-remote mode.
4219 *** Changes in GDB 6.7
4221 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4222 bfd, libiberty and opcodes, as revealed by static analysis donated by
4223 Coverity, Inc. (http://scan.coverity.com).
4225 * When looking up multiply-defined global symbols, GDB will now prefer the
4226 symbol definition in the current shared library if it was built using the
4227 -Bsymbolic linker option.
4229 * When the Text User Interface (TUI) is not configured, GDB will now
4230 recognize the -tui command-line option and print a message that the TUI
4233 * The GDB remote stub, gdbserver, now has lower overhead for high
4234 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4236 * GDB for MIPS targets now autodetects whether a remote target provides
4237 32-bit or 64-bit register values.
4239 * Support for C++ member pointers has been improved.
4241 * GDB now understands XML target descriptions, which specify the
4242 target's overall architecture. GDB can read a description from
4243 a local file or over the remote serial protocol.
4245 * Vectors of single-byte data use a new integer type which is not
4246 automatically displayed as character or string data.
4248 * The /s format now works with the print command. It displays
4249 arrays of single-byte integers and pointers to single-byte integers
4252 * Target descriptions can now describe target-specific registers,
4253 for architectures which have implemented the support (currently
4254 only ARM, M68K, and MIPS).
4256 * GDB and the GDB remote stub, gdbserver, now support the XScale
4259 * The GDB remote stub, gdbserver, has been updated to support
4260 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4261 has been rewritten to use the standard GDB remote protocol.
4263 * GDB can now step into C++ functions which are called through thunks.
4265 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4267 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4268 layout. It also supports a TextSeg= and DataSeg= response when only
4269 segment base addresses (rather than offsets) are available.
4271 * The /i format now outputs any trailing branch delay slot instructions
4272 immediately following the last instruction within the count specified.
4274 * The GDB remote protocol "T" stop reply packet now supports a
4275 "library" response. Combined with the new "qXfer:libraries:read"
4276 packet, this response allows GDB to debug shared libraries on targets
4277 where the operating system manages the list of loaded libraries (e.g.
4278 Windows and SymbianOS).
4280 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4281 (DLLs) on Windows and Windows CE targets.
4283 * GDB now supports a faster verification that a .debug file matches its binary
4284 according to its build-id signature, if the signature is present.
4290 Enable or disable hardware flow control (RTS/CTS) on the serial port
4291 when debugging using remote targets.
4293 set mem inaccessible-by-default
4294 show mem inaccessible-by-default
4295 If the target supplies a memory map, for instance via the remote
4296 protocol's "qXfer:memory-map:read" packet, setting this variable
4297 prevents GDB from accessing memory outside the memory map. This
4298 is useful for targets with memory mapped registers or which react
4299 badly to accesses of unmapped address space.
4301 set breakpoint auto-hw
4302 show breakpoint auto-hw
4303 If the target supplies a memory map, for instance via the remote
4304 protocol's "qXfer:memory-map:read" packet, setting this variable
4305 lets GDB use hardware breakpoints automatically for memory regions
4306 where it can not use software breakpoints. This covers both the
4307 "break" command and internal breakpoints used for other commands
4308 including "next" and "finish".
4311 catch exception unhandled
4312 Stop the program execution when Ada exceptions are raised.
4315 Stop the program execution when an Ada assertion failed.
4319 Set an alternate system root for target files. This is a more
4320 general version of "set solib-absolute-prefix", which is now
4321 an alias to "set sysroot".
4324 Provide extended SPU facility status information. This set of
4325 commands is available only when debugging the Cell/B.E. SPU
4328 * New native configurations
4330 OpenBSD/sh sh*-*openbsd*
4333 unset tdesc filename
4335 Use the specified local file as an XML target description, and do
4336 not query the target for its built-in description.
4340 OpenBSD/sh sh*-*-openbsd*
4341 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4342 Toshiba Media Processor mep-elf
4344 * New remote packets
4347 Ignore the specified signals; pass them directly to the debugged program
4348 without stopping other threads or reporting them to GDB.
4350 qXfer:features:read:
4351 Read an XML target description from the target, which describes its
4356 Read or write contents of an spufs file on the target system. These
4357 packets are available only on the Cell/B.E. SPU architecture.
4359 qXfer:libraries:read:
4360 Report the loaded shared libraries. Combined with new "T" packet
4361 response, this packet allows GDB to debug shared libraries on
4362 targets where the operating system manages the list of loaded
4363 libraries (e.g. Windows and SymbianOS).
4367 Support for these obsolete configurations has been removed.
4375 i[34567]86-*-lynxos*
4376 i[34567]86-*-netware*
4377 i[34567]86-*-sco3.2v5*
4378 i[34567]86-*-sco3.2v4*
4380 i[34567]86-*-sysv4.2*
4383 i[34567]86-*-unixware2*
4384 i[34567]86-*-unixware*
4393 * Other removed features
4400 Various m68k-only ROM monitors.
4407 Various Renesas ROM monitors and debugging interfaces for SH and
4412 Support for a Macraigor serial interface to on-chip debugging.
4413 GDB does not directly support the newer parallel or USB
4418 A debug information format. The predecessor to DWARF 2 and
4419 DWARF 3, which are still supported.
4421 Support for the HP aCC compiler on HP-UX/PA-RISC
4423 SOM-encapsulated symbolic debugging information, automatic
4424 invocation of pxdb, and the aCC custom C++ ABI. This does not
4425 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4426 with aCC can still be debugged on an assembly level.
4428 MIPS ".pdr" sections
4430 A MIPS-specific format used to describe stack frame layout
4431 in debugging information.
4435 GDB could work with an older version of Guile to debug
4436 the interpreter and Scheme programs running in it.
4438 set mips stack-arg-size
4439 set mips saved-gpreg-size
4441 Use "set mips abi" to control parameter passing for MIPS.
4443 *** Changes in GDB 6.6
4448 Cell Broadband Engine SPU spu-elf
4450 * GDB can now be configured as a cross-debugger targeting native Windows
4451 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4452 running on a Windows system over TCP/IP to debug Windows programs.
4454 * The GDB remote stub, gdbserver, has been updated to support Windows and
4455 Cygwin debugging. Both single-threaded and multi-threaded programs are
4458 * The "set trust-readonly-sections" command works again. This command was
4459 broken in GDB 6.3, 6.4, and 6.5.
4461 * The "load" command now supports writing to flash memory, if the remote
4462 stub provides the required support.
4464 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4465 longer requires symbolic debug information (e.g. DWARF-2).
4470 unset substitute-path
4471 show substitute-path
4472 Manage a list of substitution rules that GDB uses to rewrite the name
4473 of the directories where the sources are located. This can be useful
4474 for instance when the sources were moved to a different location
4475 between compilation and debugging.
4479 Print each CLI command as it is executed. Each command is prefixed with
4480 a number of `+' symbols representing the nesting depth.
4481 The source command now has a `-v' option to enable the same feature.
4485 The ARM Demon monitor support (RDP protocol, "target rdp").
4487 Kernel Object Display, an embedded debugging feature which only worked with
4488 an obsolete version of Cisco IOS.
4490 The 'set download-write-size' and 'show download-write-size' commands.
4492 * New remote packets
4495 Tell a stub about GDB client features, and request remote target features.
4496 The first feature implemented is PacketSize, which allows the target to
4497 specify the size of packets it can handle - to minimize the number of
4498 packets required and improve performance when connected to a remote
4502 Fetch an OS auxilliary vector from the remote stub. This packet is a
4503 more efficient replacement for qPart:auxv:read.
4505 qXfer:memory-map:read:
4506 Fetch a memory map from the remote stub, including information about
4507 RAM, ROM, and flash memory devices.
4512 Erase and program a flash memory device.
4514 * Removed remote packets
4517 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4518 used it, and only gdbserver implemented it.
4520 *** Changes in GDB 6.5
4524 Renesas M32C/M16C m32c-elf
4526 Morpho Technologies ms1 ms1-elf
4530 init-if-undefined Initialize a convenience variable, but
4531 only if it doesn't already have a value.
4533 The following commands are presently only implemented for native GNU/Linux:
4535 checkpoint Save a snapshot of the program state.
4537 restart <n> Return the program state to a
4538 previously saved state.
4540 info checkpoints List currently saved checkpoints.
4542 delete-checkpoint <n> Delete a previously saved checkpoint.
4544 set|show detach-on-fork Tell gdb whether to detach from a newly
4545 forked process, or to keep debugging it.
4547 info forks List forks of the user program that
4548 are available to be debugged.
4550 fork <n> Switch to debugging one of several
4551 forks of the user program that are
4552 available to be debugged.
4554 delete-fork <n> Delete a fork from the list of forks
4555 that are available to be debugged (and
4556 kill the forked process).
4558 detach-fork <n> Delete a fork from the list of forks
4559 that are available to be debugged (and
4560 allow the process to continue).
4564 Morpho Technologies ms2 ms1-elf
4566 * Improved Windows host support
4568 GDB now builds as a cross debugger hosted on i686-mingw32, including
4569 native console support, and remote communications using either
4570 network sockets or serial ports.
4572 * Improved Modula-2 language support
4574 GDB can now print most types in the Modula-2 syntax. This includes:
4575 basic types, set types, record types, enumerated types, range types,
4576 pointer types and ARRAY types. Procedure var parameters are correctly
4577 printed and hexadecimal addresses and character constants are also
4578 written in the Modula-2 syntax. Best results can be obtained by using
4579 GNU Modula-2 together with the -gdwarf-2 command line option.
4583 The ARM rdi-share module.
4585 The Netware NLM debug server.
4587 *** Changes in GDB 6.4
4589 * New native configurations
4591 OpenBSD/arm arm*-*-openbsd*
4592 OpenBSD/mips64 mips64-*-openbsd*
4596 Morpho Technologies ms1 ms1-elf
4598 * New command line options
4600 --batch-silent As for --batch, but totally silent.
4601 --return-child-result The debugger will exist with the same value
4602 the child (debugged) program exited with.
4603 --eval-command COMMAND, -ex COMMAND
4604 Execute a single GDB CLI command. This may be
4605 specified multiple times and in conjunction
4606 with the --command (-x) option.
4608 * Deprecated commands removed
4610 The following commands, that were deprecated in 2000, have been
4614 set|show arm disassembly-flavor set|show arm disassembler
4615 othernames set arm disassembler
4616 set|show remotedebug set|show debug remote
4617 set|show archdebug set|show debug arch
4618 set|show eventdebug set|show debug event
4621 * New BSD user-level threads support
4623 It is now possible to debug programs using the user-level threads
4624 library on OpenBSD and FreeBSD. Currently supported (target)
4627 FreeBSD/amd64 x86_64-*-freebsd*
4628 FreeBSD/i386 i386-*-freebsd*
4629 OpenBSD/i386 i386-*-openbsd*
4631 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4632 are not yet supported.
4634 * New support for Matsushita MN10300 w/sim added
4635 (Work in progress). mn10300-elf.
4637 * REMOVED configurations and files
4639 VxWorks and the XDR protocol *-*-vxworks
4640 Motorola MCORE mcore-*-*
4641 National Semiconductor NS32000 ns32k-*-*
4643 * New "set print array-indexes" command
4645 After turning this setting "on", GDB prints the index of each element
4646 when displaying arrays. The default is "off" to preserve the previous
4649 * VAX floating point support
4651 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4653 * User-defined command support
4655 In addition to using $arg0..$arg9 for argument passing, it is now possible
4656 to use $argc to determine now many arguments have been passed. See the
4657 section on user-defined commands in the user manual for more information.
4659 *** Changes in GDB 6.3:
4661 * New command line option
4663 GDB now accepts -l followed by a number to set the timeout for remote
4666 * GDB works with GCC -feliminate-dwarf2-dups
4668 GDB now supports a more compact representation of DWARF-2 debug
4669 information using DW_FORM_ref_addr references. These are produced
4670 by GCC with the option -feliminate-dwarf2-dups and also by some
4671 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4672 to use -feliminate-dwarf2-dups.
4674 * Internationalization
4676 When supported by the host system, GDB will be built with
4677 internationalization (libintl). The task of marking up the sources is
4678 continued, we're looking forward to our first translation.
4682 Initial support for debugging programs compiled with the GNAT
4683 implementation of the Ada programming language has been integrated
4684 into GDB. In this release, support is limited to expression evaluation.
4686 * New native configurations
4688 GNU/Linux/m32r m32r-*-linux-gnu
4692 GDB's remote protocol now includes support for the 'p' packet. This
4693 packet is used to fetch individual registers from a remote inferior.
4695 * END-OF-LIFE registers[] compatibility module
4697 GDB's internal register infrastructure has been completely rewritten.
4698 The new infrastructure making possible the implementation of key new
4699 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4702 GDB 6.3 will be the last release to include the the registers[]
4703 compatibility module that allowed out-of-date configurations to
4704 continue to work. This change directly impacts the following
4714 powerpc bdm protocol
4716 Unless there is activity to revive these configurations, they will be
4717 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4719 * OBSOLETE configurations and files
4721 Configurations that have been declared obsolete in this release have
4722 been commented out. Unless there is activity to revive these
4723 configurations, the next release of GDB will have their sources
4724 permanently REMOVED.
4733 *** Changes in GDB 6.2.1:
4735 * MIPS `break main; run' gave an heuristic-fence-post warning
4737 When attempting to run even a simple program, a warning about
4738 heuristic-fence-post being hit would be reported. This problem has
4741 * MIPS IRIX 'long double' crashed GDB
4743 When examining a long double variable, GDB would get a segmentation
4744 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4745 IRIX long double values).
4749 A bug in the VAX stack code was causing problems with the "next"
4750 command. This problem has been fixed.
4752 *** Changes in GDB 6.2:
4754 * Fix for ``many threads''
4756 On GNU/Linux systems that use the NPTL threads library, a program
4757 rapidly creating and deleting threads would confuse GDB leading to the
4760 ptrace: No such process.
4761 thread_db_get_info: cannot get thread info: generic error
4763 This problem has been fixed.
4765 * "-async" and "-noasync" options removed.
4767 Support for the broken "-noasync" option has been removed (it caused
4770 * New ``start'' command.
4772 This command runs the program until the begining of the main procedure.
4774 * New BSD Kernel Data Access Library (libkvm) interface
4776 Using ``target kvm'' it is now possible to debug kernel core dumps and
4777 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4778 platforms. Currently supported (native-only) configurations are:
4780 FreeBSD/amd64 x86_64-*-freebsd*
4781 FreeBSD/i386 i?86-*-freebsd*
4782 NetBSD/i386 i?86-*-netbsd*
4783 NetBSD/m68k m68*-*-netbsd*
4784 NetBSD/sparc sparc-*-netbsd*
4785 OpenBSD/amd64 x86_64-*-openbsd*
4786 OpenBSD/i386 i?86-*-openbsd*
4787 OpenBSD/m68k m68*-openbsd*
4788 OpenBSD/sparc sparc-*-openbsd*
4790 * Signal trampoline code overhauled
4792 Many generic problems with GDB's signal handling code have been fixed.
4793 These include: backtraces through non-contiguous stacks; recognition
4794 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4795 call; backtrace through a signal trampoline; step into and out of
4796 signal handlers; and single-stepping in the signal trampoline.
4798 Please note that kernel bugs are a limiting factor here. These
4799 features have been shown to work on an s390 GNU/Linux system that
4800 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4802 * Cygwin support for DWARF 2 added.
4804 * New native configurations
4806 GNU/Linux/hppa hppa*-*-linux*
4807 OpenBSD/hppa hppa*-*-openbsd*
4808 OpenBSD/m68k m68*-*-openbsd*
4809 OpenBSD/m88k m88*-*-openbsd*
4810 OpenBSD/powerpc powerpc-*-openbsd*
4811 NetBSD/vax vax-*-netbsd*
4812 OpenBSD/vax vax-*-openbsd*
4814 * END-OF-LIFE frame compatibility module
4816 GDB's internal frame infrastructure has been completely rewritten.
4817 The new infrastructure making it possible to support key new features
4818 including DWARF 2 Call Frame Information. To aid in the task of
4819 migrating old configurations to this new infrastructure, a
4820 compatibility module, that allowed old configurations to continue to
4821 work, was also included.
4823 GDB 6.2 will be the last release to include this frame compatibility
4824 module. This change directly impacts the following configurations:
4834 Unless there is activity to revive these configurations, they will be
4835 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4837 * REMOVED configurations and files
4839 Sun 3, running SunOS 3 m68*-*-sunos3*
4840 Sun 3, running SunOS 4 m68*-*-sunos4*
4841 Sun 2, running SunOS 3 m68000-*-sunos3*
4842 Sun 2, running SunOS 4 m68000-*-sunos4*
4843 Motorola 680x0 running LynxOS m68*-*-lynxos*
4844 AT&T 3b1/Unix pc m68*-att-*
4845 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4846 decstation mips-dec-* mips-little-*
4847 riscos mips-*-riscos* mips-*-sysv*
4848 sonymips mips-sony-*
4849 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4851 *** Changes in GDB 6.1.1:
4853 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4855 The TUI (Text-mode User Interface) is now built as part of a default
4856 GDB configuration. It is enabled by either selecting the TUI with the
4857 command line option "-i=tui" or by running the separate "gdbtui"
4858 program. For more information on the TUI, see the manual "Debugging
4861 * Pending breakpoint support (also included in GDB 6.1)
4863 Support has been added to allow you to specify breakpoints in shared
4864 libraries that have not yet been loaded. If a breakpoint location
4865 cannot be found, and the "breakpoint pending" option is set to auto,
4866 GDB queries you if you wish to make the breakpoint pending on a future
4867 shared-library load. If and when GDB resolves the breakpoint symbol,
4868 the pending breakpoint is removed as one or more regular breakpoints
4871 Pending breakpoints are very useful for GCJ Java debugging.
4873 * Fixed ISO-C build problems
4875 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4876 non ISO-C code that stopped them being built using a more strict ISO-C
4877 compiler (e.g., IBM's C compiler).
4879 * Fixed build problem on IRIX 5
4881 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4882 wasn't able to compile compile on an IRIX 5 system.
4884 * Added execute permission to gdb/gdbserver/configure
4886 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4887 permission. This bug would cause configure to fail on a number of
4888 systems (Solaris, IRIX). Ref: server/519.
4890 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4892 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4893 has been updated to use constant array sizes.
4895 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4897 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4898 its generated DWARF Call Frame Info. This encoding was causing GDB to
4899 panic, that panic has been fixed. Ref: gdb/1628.
4901 * Fixed a problem when examining parameters in shared library code.
4903 When examining parameters in optimized shared library code generated
4904 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4905 not available''. GDB now correctly displays the variable's value.
4907 *** Changes in GDB 6.1:
4909 * Removed --with-mmalloc
4911 Support for the mmalloc memory manager has been removed, as it
4912 conflicted with the internal gdb byte cache.
4914 * Changes in AMD64 configurations
4916 The AMD64 target now includes the %cs and %ss registers. As a result
4917 the AMD64 remote protocol has changed; this affects the floating-point
4918 and SSE registers. If you rely on those registers for your debugging,
4919 you should upgrade gdbserver on the remote side.
4921 * Revised SPARC target
4923 The SPARC target has been completely revised, incorporating the
4924 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4925 support for LynxOS and SunOS 4 has been dropped. Calling functions
4926 from within GDB on operating systems with a non-executable stack
4927 (Solaris, OpenBSD) now works.
4931 GDB has a new C++ demangler which does a better job on the mangled
4932 names generated by current versions of g++. It also runs faster, so
4933 with this and other changes gdb should now start faster on large C++
4936 * DWARF 2 Location Expressions
4938 GDB support for location expressions has been extended to support function
4939 arguments and frame bases. Older versions of GDB could crash when they
4942 * C++ nested types and namespaces
4944 GDB's support for nested types and namespaces in C++ has been
4945 improved, especially if you use the DWARF 2 debugging format. (This
4946 is the default for recent versions of GCC on most platforms.)
4947 Specifically, if you have a class "Inner" defined within a class or
4948 namespace "Outer", then GDB realizes that the class's name is
4949 "Outer::Inner", not simply "Inner". This should greatly reduce the
4950 frequency of complaints about not finding RTTI symbols. In addition,
4951 if you are stopped at inside of a function defined within a namespace,
4952 GDB modifies its name lookup accordingly.
4954 * New native configurations
4956 NetBSD/amd64 x86_64-*-netbsd*
4957 OpenBSD/amd64 x86_64-*-openbsd*
4958 OpenBSD/alpha alpha*-*-openbsd*
4959 OpenBSD/sparc sparc-*-openbsd*
4960 OpenBSD/sparc64 sparc64-*-openbsd*
4962 * New debugging protocols
4964 M32R with SDI protocol m32r-*-elf*
4966 * "set prompt-escape-char" command deleted.
4968 The command "set prompt-escape-char" has been deleted. This command,
4969 and its very obscure effet on GDB's prompt, was never documented,
4970 tested, nor mentioned in the NEWS file.
4972 * OBSOLETE configurations and files
4974 Configurations that have been declared obsolete in this release have
4975 been commented out. Unless there is activity to revive these
4976 configurations, the next release of GDB will have their sources
4977 permanently REMOVED.
4979 Sun 3, running SunOS 3 m68*-*-sunos3*
4980 Sun 3, running SunOS 4 m68*-*-sunos4*
4981 Sun 2, running SunOS 3 m68000-*-sunos3*
4982 Sun 2, running SunOS 4 m68000-*-sunos4*
4983 Motorola 680x0 running LynxOS m68*-*-lynxos*
4984 AT&T 3b1/Unix pc m68*-att-*
4985 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4986 decstation mips-dec-* mips-little-*
4987 riscos mips-*-riscos* mips-*-sysv*
4988 sonymips mips-sony-*
4989 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4991 * REMOVED configurations and files
4993 SGI Irix-4.x mips-sgi-irix4 or iris4
4994 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4995 Z8000 simulator z8k-zilog-none or z8ksim
4996 Matsushita MN10200 w/simulator mn10200-*-*
4997 H8/500 simulator h8500-hitachi-hms or h8500hms
4998 HP/PA running BSD hppa*-*-bsd*
4999 HP/PA running OSF/1 hppa*-*-osf*
5000 HP/PA Pro target hppa*-*-pro*
5001 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5002 386BSD i[3456]86-*-bsd*
5003 Sequent family i[3456]86-sequent-sysv4*
5004 i[3456]86-sequent-sysv*
5005 i[3456]86-sequent-bsd*
5006 SPARC running LynxOS sparc-*-lynxos*
5007 SPARC running SunOS 4 sparc-*-sunos4*
5008 Tsqware Sparclet sparclet-*-*
5009 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5011 *** Changes in GDB 6.0:
5015 Support for debugging the Objective-C programming language has been
5016 integrated into GDB.
5018 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5020 DWARF 2's Call Frame Information makes available compiler generated
5021 information that more exactly describes the program's run-time stack.
5022 By using this information, GDB is able to provide more robust stack
5025 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5026 have been updated to use a new backtrace mechanism which includes
5027 DWARF 2 CFI support.
5031 GDB's remote protocol has been extended to include support for hosted
5032 file I/O (where the remote target uses GDB's file system). See GDB's
5033 remote protocol documentation for details.
5035 * All targets using the new architecture framework.
5037 All of GDB's targets have been updated to use the new internal
5038 architecture framework. The way is now open for future GDB releases
5039 to include cross-architecture native debugging support (i386 on amd64,
5042 * GNU/Linux's Thread Local Storage (TLS)
5044 GDB now includes support for for the GNU/Linux implementation of
5045 per-thread variables.
5047 * GNU/Linux's Native POSIX Thread Library (NPTL)
5049 GDB's thread code has been updated to work with either the new
5050 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5052 * Separate debug info.
5054 GDB, in conjunction with BINUTILS, now supports a mechanism for
5055 automatically loading debug information from a separate file. Instead
5056 of shipping full debug and non-debug versions of system libraries,
5057 system integrators can now instead ship just the stripped libraries
5058 and optional debug files.
5060 * DWARF 2 Location Expressions
5062 DWARF 2 Location Expressions allow the compiler to more completely
5063 describe the location of variables (even in optimized code) to the
5066 GDB now includes preliminary support for location expressions (support
5067 for DW_OP_piece is still missing).
5071 A number of long standing bugs that caused GDB to die while starting a
5072 Java application have been fixed. GDB's Java support is now
5073 considered "useable".
5075 * GNU/Linux support for fork, vfork, and exec.
5077 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5078 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5081 * GDB supports logging output to a file
5083 There are two new commands, "set logging" and "show logging", which can be
5084 used to capture GDB's output to a file.
5086 * The meaning of "detach" has changed for gdbserver
5088 The "detach" command will now resume the application, as documented. To
5089 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5092 * d10v, m68hc11 `regs' command deprecated
5094 The `info registers' command has been updated so that it displays the
5095 registers using a format identical to the old `regs' command.
5099 A new command, "maint set profile on/off", has been added. This command can
5100 be used to enable or disable profiling while running GDB, to profile a
5101 session or a set of commands. In addition there is a new configure switch,
5102 "--enable-profiling", which will cause GDB to be compiled with profiling
5103 data, for more informative profiling results.
5105 * Default MI syntax changed to "mi2".
5107 The default MI (machine interface) syntax, enabled by the command line
5108 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5109 "mi1", can be enabled by specifying the option "-i=mi1".
5111 Support for the original "mi0" syntax (included in GDB 5.0) has been
5114 Fix for gdb/192: removed extraneous space when displaying frame level.
5115 Fix for gdb/672: update changelist is now output in mi list format.
5116 Fix for gdb/702: a -var-assign that updates the value now shows up
5117 in a subsequent -var-update.
5119 * New native configurations.
5121 FreeBSD/amd64 x86_64-*-freebsd*
5123 * Multi-arched targets.
5125 HP/PA HPUX11 hppa*-*-hpux*
5126 Renesas M32R/D w/simulator m32r-*-elf*
5128 * OBSOLETE configurations and files
5130 Configurations that have been declared obsolete in this release have
5131 been commented out. Unless there is activity to revive these
5132 configurations, the next release of GDB will have their sources
5133 permanently REMOVED.
5135 Z8000 simulator z8k-zilog-none or z8ksim
5136 Matsushita MN10200 w/simulator mn10200-*-*
5137 H8/500 simulator h8500-hitachi-hms or h8500hms
5138 HP/PA running BSD hppa*-*-bsd*
5139 HP/PA running OSF/1 hppa*-*-osf*
5140 HP/PA Pro target hppa*-*-pro*
5141 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5142 Sequent family i[3456]86-sequent-sysv4*
5143 i[3456]86-sequent-sysv*
5144 i[3456]86-sequent-bsd*
5145 Tsqware Sparclet sparclet-*-*
5146 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5148 * REMOVED configurations and files
5151 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5152 IBM AIX PS/2 i[3456]86-*-aix
5153 i386 running Mach 3.0 i[3456]86-*-mach3*
5154 i386 running Mach i[3456]86-*-mach*
5155 i386 running OSF/1 i[3456]86-*osf1mk*
5156 HP/Apollo 68k Family m68*-apollo*-sysv*,
5158 m68*-hp-bsd*, m68*-hp-hpux*
5159 Argonaut Risc Chip (ARC) arc-*-*
5160 Mitsubishi D30V d30v-*-*
5161 Fujitsu FR30 fr30-*-elf*
5162 OS/9000 i[34]86-*-os9k
5163 I960 with MON960 i960-*-coff
5165 * MIPS $fp behavior changed
5167 The convenience variable $fp, for the MIPS, now consistently returns
5168 the address of the current frame's base. Previously, depending on the
5169 context, $fp could refer to either $sp or the current frame's base
5170 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5171 The GNU Source-Level Debugger''.
5173 *** Changes in GDB 5.3:
5175 * GNU/Linux shared library multi-threaded performance improved.
5177 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5178 `/proc', in preference to `ptrace' for memory reads. This may result
5179 in an improvement in the start-up time of multi-threaded, shared
5180 library applications when run under GDB. One GDB user writes: ``loads
5181 shared libs like mad''.
5183 * ``gdbserver'' now supports multi-threaded applications on some targets
5185 Support for debugging multi-threaded applications which use
5186 the GNU/Linux LinuxThreads package has been added for
5187 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5188 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5190 * GDB now supports C/C++ preprocessor macros.
5192 GDB now expands preprocessor macro invocations in C/C++ expressions,
5193 and provides various commands for showing macro definitions and how
5196 The new command `macro expand EXPRESSION' expands any macro
5197 invocations in expression, and shows the result.
5199 The new command `show macro MACRO-NAME' shows the definition of the
5200 macro named MACRO-NAME, and where it was defined.
5202 Most compilers don't include information about macros in the debugging
5203 information by default. In GCC 3.1, for example, you need to compile
5204 your program with the options `-gdwarf-2 -g3'. If the macro
5205 information is present in the executable, GDB will read it.
5207 * Multi-arched targets.
5209 DEC Alpha (partial) alpha*-*-*
5210 DEC VAX (partial) vax-*-*
5212 National Semiconductor NS32000 (partial) ns32k-*-*
5213 Motorola 68000 (partial) m68k-*-*
5214 Motorola MCORE mcore-*-*
5218 Fujitsu FRV architecture added by Red Hat frv*-*-*
5221 * New native configurations
5223 Alpha NetBSD alpha*-*-netbsd*
5224 SH NetBSD sh*-*-netbsdelf*
5225 MIPS NetBSD mips*-*-netbsd*
5226 UltraSPARC NetBSD sparc64-*-netbsd*
5228 * OBSOLETE configurations and files
5230 Configurations that have been declared obsolete in this release have
5231 been commented out. Unless there is activity to revive these
5232 configurations, the next release of GDB will have their sources
5233 permanently REMOVED.
5235 Mitsubishi D30V d30v-*-*
5236 OS/9000 i[34]86-*-os9k
5237 IBM AIX PS/2 i[3456]86-*-aix
5238 Fujitsu FR30 fr30-*-elf*
5239 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5240 Argonaut Risc Chip (ARC) arc-*-*
5241 i386 running Mach 3.0 i[3456]86-*-mach3*
5242 i386 running Mach i[3456]86-*-mach*
5243 i386 running OSF/1 i[3456]86-*osf1mk*
5244 HP/Apollo 68k Family m68*-apollo*-sysv*,
5246 m68*-hp-bsd*, m68*-hp-hpux*
5247 I960 with MON960 i960-*-coff
5249 * OBSOLETE languages
5251 CHILL, a Pascal like language used by telecommunications companies.
5253 * REMOVED configurations and files
5255 AMD 29k family via UDI a29k-amd-udi, udi29k
5256 A29K VxWorks a29k-*-vxworks
5257 AMD 29000 embedded, using EBMON a29k-none-none
5258 AMD 29000 embedded with COFF a29k-none-coff
5259 AMD 29000 embedded with a.out a29k-none-aout
5261 testsuite/gdb.hp/gdb.threads-hp/ directory
5263 * New command "set max-user-call-depth <nnn>"
5265 This command allows the user to limit the call depth of user-defined
5266 commands. The default is 1024.
5268 * Changes in FreeBSD/i386 native debugging.
5270 Support for the "generate-core-file" has been added.
5272 * New commands "dump", "append", and "restore".
5274 These commands allow data to be copied from target memory
5275 to a bfd-format or binary file (dump and append), and back
5276 from a file into memory (restore).
5278 * Improved "next/step" support on multi-processor Alpha Tru64.
5280 The previous single-step mechanism could cause unpredictable problems,
5281 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5282 of a software single-step mechanism prevents this.
5284 *** Changes in GDB 5.2.1:
5292 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5293 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5294 Fix, by Joel Brobecker imported from mainline.
5296 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5297 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5298 Fix, by Fred Fish, imported from mainline.
5300 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5301 Surprisingly enough, it works now.
5302 By Michal Ludvig, imported from mainline.
5304 i386 hardware watchpoint support:
5305 avoid misses on second run for some targets.
5306 By Pierre Muller, imported from mainline.
5308 *** Changes in GDB 5.2:
5310 * New command "set trust-readonly-sections on[off]".
5312 This command is a hint that tells gdb that read-only sections
5313 really are read-only (ie. that their contents will not change).
5314 In this mode, gdb will go to the object file rather than the
5315 target to read memory from read-only sections (such as ".text").
5316 This can be a significant performance improvement on some
5317 (notably embedded) targets.
5319 * New command "generate-core-file" (or "gcore").
5321 This new gdb command allows the user to drop a core file of the child
5322 process state at any time. So far it's been implemented only for
5323 GNU/Linux and Solaris, but should be relatively easily ported to other
5324 hosts. Argument is core file name (defaults to core.<pid>).
5326 * New command line option
5328 GDB now accepts --pid or -p followed by a process id.
5330 * Change in command line behavior -- corefiles vs. process ids.
5332 There is a subtle behavior in the way in which GDB handles
5333 command line arguments. The first non-flag argument is always
5334 a program to debug, but the second non-flag argument may either
5335 be a corefile or a process id. Previously, GDB would attempt to
5336 open the second argument as a corefile, and if that failed, would
5337 issue a superfluous error message and then attempt to attach it as
5338 a process. Now, if the second argument begins with a non-digit,
5339 it will be treated as a corefile. If it begins with a digit,
5340 GDB will attempt to attach it as a process, and if no such process
5341 is found, will then attempt to open it as a corefile.
5343 * Changes in ARM configurations.
5345 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5346 configuration is fully multi-arch.
5348 * New native configurations
5350 ARM NetBSD arm*-*-netbsd*
5351 x86 OpenBSD i[3456]86-*-openbsd*
5352 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5353 Sparc64 running FreeBSD sparc64-*-freebsd*
5357 Sanyo XStormy16 xstormy16-elf
5359 * OBSOLETE configurations and files
5361 Configurations that have been declared obsolete in this release have
5362 been commented out. Unless there is activity to revive these
5363 configurations, the next release of GDB will have their sources
5364 permanently REMOVED.
5366 AMD 29k family via UDI a29k-amd-udi, udi29k
5367 A29K VxWorks a29k-*-vxworks
5368 AMD 29000 embedded, using EBMON a29k-none-none
5369 AMD 29000 embedded with COFF a29k-none-coff
5370 AMD 29000 embedded with a.out a29k-none-aout
5372 testsuite/gdb.hp/gdb.threads-hp/ directory
5374 * REMOVED configurations and files
5376 TI TMS320C80 tic80-*-*
5378 PowerPC Solaris powerpcle-*-solaris*
5379 PowerPC Windows NT powerpcle-*-cygwin32
5380 PowerPC Netware powerpc-*-netware*
5381 Harris/CXUX m88k m88*-harris-cxux*
5382 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5383 ns32k-utek-sysv* ns32k-utek-*
5384 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5385 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5386 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5387 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5388 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5390 * Changes to command line processing
5392 The new `--args' feature can be used to specify command-line arguments
5393 for the inferior from gdb's command line.
5395 * Changes to key bindings
5397 There is a new `operate-and-get-next' function bound to `C-o'.
5399 *** Changes in GDB 5.1.1
5401 Fix compile problem on DJGPP.
5403 Fix a problem with floating-point registers on the i386 being
5406 Fix to stop GDB crashing on .debug_str debug info.
5408 Numerous documentation fixes.
5410 Numerous testsuite fixes.
5412 *** Changes in GDB 5.1:
5414 * New native configurations
5416 Alpha FreeBSD alpha*-*-freebsd*
5417 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5418 MIPS GNU/Linux mips*-*-linux*
5419 MIPS SGI Irix 6.x mips*-sgi-irix6*
5420 ia64 AIX ia64-*-aix*
5421 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5425 Motorola 68HC11 and 68HC12 m68hc11-elf
5427 UltraSparc running GNU/Linux sparc64-*-linux*
5429 * OBSOLETE configurations and files
5431 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5432 Harris/CXUX m88k m88*-harris-cxux*
5433 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5434 ns32k-utek-sysv* ns32k-utek-*
5435 TI TMS320C80 tic80-*-*
5437 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5438 PowerPC Solaris powerpcle-*-solaris*
5439 PowerPC Windows NT powerpcle-*-cygwin32
5440 PowerPC Netware powerpc-*-netware*
5441 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5442 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5443 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5444 Apple Macintosh (MPW) host N/A
5446 stuff.c (Program to stuff files into a specially prepared space in kdb)
5447 kdb-start.c (Main loop for the standalone kernel debugger)
5449 Configurations that have been declared obsolete in this release have
5450 been commented out. Unless there is activity to revive these
5451 configurations, the next release of GDB will have their sources
5452 permanently REMOVED.
5454 * REMOVED configurations and files
5456 Altos 3068 m68*-altos-*
5457 Convex c1-*-*, c2-*-*
5459 ARM RISCix arm-*-* (as host)
5463 * GDB has been converted to ISO C.
5465 GDB's source code has been converted to ISO C. In particular, the
5466 sources are fully protoized, and rely on standard headers being
5471 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5473 * The MI enabled by default.
5475 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5476 revised and enabled by default. Packages which use GDB as a debugging
5477 engine behind a UI or another front end are encouraged to switch to
5478 using the GDB/MI interface, instead of the old annotations interface
5479 which is now deprecated.
5481 * Support for debugging Pascal programs.
5483 GDB now includes support for debugging Pascal programs. The following
5484 main features are supported:
5486 - Pascal-specific data types such as sets;
5488 - automatic recognition of Pascal sources based on file-name
5491 - Pascal-style display of data types, variables, and functions;
5493 - a Pascal expression parser.
5495 However, some important features are not yet supported.
5497 - Pascal string operations are not supported at all;
5499 - there are some problems with boolean types;
5501 - Pascal type hexadecimal constants are not supported
5502 because they conflict with the internal variables format;
5504 - support for Pascal objects and classes is not full yet;
5506 - unlike Pascal, GDB is case-sensitive for symbol names.
5508 * Changes in completion.
5510 Commands such as `shell', `run' and `set args', which pass arguments
5511 to inferior programs, now complete on file names, similar to what
5512 users expect at the shell prompt.
5514 Commands which accept locations, such as `disassemble', `print',
5515 `breakpoint', `until', etc. now complete on filenames as well as
5516 program symbols. Thus, if you type "break foob TAB", and the source
5517 files linked into the programs include `foobar.c', that file name will
5518 be one of the candidates for completion. However, file names are not
5519 considered for completion after you typed a colon that delimits a file
5520 name from a name of a function in that file, as in "break foo.c:bar".
5522 `set demangle-style' completes on available demangling styles.
5524 * New platform-independent commands:
5526 It is now possible to define a post-hook for a command as well as a
5527 hook that runs before the command. For more details, see the
5528 documentation of `hookpost' in the GDB manual.
5530 * Changes in GNU/Linux native debugging.
5532 Support for debugging multi-threaded programs has been completely
5533 revised for all platforms except m68k and sparc. You can now debug as
5534 many threads as your system allows you to have.
5536 Attach/detach is supported for multi-threaded programs.
5538 Support for SSE registers was added for x86. This doesn't work for
5539 multi-threaded programs though.
5541 * Changes in MIPS configurations.
5543 Multi-arch support is enabled for all MIPS configurations.
5545 GDB can now be built as native debugger on SGI Irix 6.x systems for
5546 debugging n32 executables. (Debugging 64-bit executables is not yet
5549 * Unified support for hardware watchpoints in all x86 configurations.
5551 Most (if not all) native x86 configurations support hardware-assisted
5552 breakpoints and watchpoints in a unified manner. This support
5553 implements debug register sharing between watchpoints, which allows to
5554 put a virtually infinite number of watchpoints on the same address,
5555 and also supports watching regions up to 16 bytes with several debug
5558 The new maintenance command `maintenance show-debug-regs' toggles
5559 debugging print-outs in functions that insert, remove, and test
5560 watchpoints and hardware breakpoints.
5562 * Changes in the DJGPP native configuration.
5564 New command ``info dos sysinfo'' displays assorted information about
5565 the CPU, OS, memory, and DPMI server.
5567 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5568 display information about segment descriptors stored in GDT, LDT, and
5571 New commands ``info dos pde'' and ``info dos pte'' display entries
5572 from Page Directory and Page Tables (for now works with CWSDPMI only).
5573 New command ``info dos address-pte'' displays the Page Table entry for
5574 a given linear address.
5576 GDB can now pass command lines longer than 126 characters to the
5577 program being debugged (requires an update to the libdbg.a library
5578 which is part of the DJGPP development kit).
5580 DWARF2 debug info is now supported.
5582 It is now possible to `step' and `next' through calls to `longjmp'.
5584 * Changes in documentation.
5586 All GDB documentation was converted to GFDL, the GNU Free
5587 Documentation License.
5589 Tracepoints-related commands are now fully documented in the GDB
5592 TUI, the Text-mode User Interface, is now documented in the manual.
5594 Tracepoints-related commands are now fully documented in the GDB
5597 The "GDB Internals" manual now has an index. It also includes
5598 documentation of `ui_out' functions, GDB coding standards, x86
5599 hardware watchpoints, and memory region attributes.
5601 * GDB's version number moved to ``version.in''
5603 The Makefile variable VERSION has been replaced by the file
5604 ``version.in''. People creating GDB distributions should update the
5605 contents of this file.
5609 GUD support is now a standard part of the EMACS distribution.
5611 *** Changes in GDB 5.0:
5613 * Improved support for debugging FP programs on x86 targets
5615 Unified and much-improved support for debugging floating-point
5616 programs on all x86 targets. In particular, ``info float'' now
5617 displays the FP registers in the same format on all x86 targets, with
5618 greater level of detail.
5620 * Improvements and bugfixes in hardware-assisted watchpoints
5622 It is now possible to watch array elements, struct members, and
5623 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5624 on x86 targets no longer erroneously trigger when the address is
5627 * Improvements in the native DJGPP version of GDB
5629 The distribution now includes all the scripts and auxiliary files
5630 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5631 machines ``out of the box''.
5633 The DJGPP version can now debug programs that use signals. It is
5634 possible to catch signals that happened in the debuggee, deliver
5635 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5636 would kill the program being debugged.) Programs that hook hardware
5637 interrupts (keyboard, timer, etc.) can also be debugged.
5639 It is now possible to debug DJGPP programs that redirect their
5640 standard handles or switch them to raw (as opposed to cooked) mode, or
5641 even close them. The command ``run < foo > bar'' works as expected,
5642 and ``info terminal'' reports useful information about the debuggee's
5643 terminal, including raw/cooked mode, redirection, etc.
5645 The DJGPP version now uses termios functions for console I/O, which
5646 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5649 DOS-style file names with drive letters are now fully supported by
5652 It is now possible to debug DJGPP programs that switch their working
5653 directory. It is also possible to rerun the debuggee any number of
5654 times without restarting GDB; thus, you can use the same setup,
5655 breakpoints, etc. for many debugging sessions.
5657 * New native configurations
5659 ARM GNU/Linux arm*-*-linux*
5660 PowerPC GNU/Linux powerpc-*-linux*
5664 Motorola MCore mcore-*-*
5665 x86 VxWorks i[3456]86-*-vxworks*
5666 PowerPC VxWorks powerpc-*-vxworks*
5667 TI TMS320C80 tic80-*-*
5669 * OBSOLETE configurations
5671 Altos 3068 m68*-altos-*
5672 Convex c1-*-*, c2-*-*
5674 ARM RISCix arm-*-* (as host)
5677 Configurations that have been declared obsolete will be commented out,
5678 but the code will be left in place. If there is no activity to revive
5679 these configurations before the next release of GDB, the sources will
5680 be permanently REMOVED.
5682 * Gould support removed
5684 Support for the Gould PowerNode and NP1 has been removed.
5686 * New features for SVR4
5688 On SVR4 native platforms (such as Solaris), if you attach to a process
5689 without first loading a symbol file, GDB will now attempt to locate and
5690 load symbols from the running process's executable file.
5692 * Many C++ enhancements
5694 C++ support has been greatly improved. Overload resolution now works properly
5695 in almost all cases. RTTI support is on the way.
5697 * Remote targets can connect to a sub-program
5699 A popen(3) style serial-device has been added. This device starts a
5700 sub-process (such as a stand-alone simulator) and then communicates
5701 with that. The sub-program to run is specified using the syntax
5702 ``|<program> <args>'' vis:
5704 (gdb) set remotedebug 1
5705 (gdb) target extended-remote |mn10300-elf-sim program-args
5707 * MIPS 64 remote protocol
5709 A long standing bug in the mips64 remote protocol where by GDB
5710 expected certain 32 bit registers (ex SR) to be transfered as 32
5711 instead of 64 bits has been fixed.
5713 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5714 added to provide backward compatibility with older versions of GDB.
5716 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5718 The command ``set remotebinarydownload'' command has been replaced by
5719 ``set remote X-packet''. Other commands in ``set remote'' family
5720 include ``set remote P-packet''.
5722 * Breakpoint commands accept ranges.
5724 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5725 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5726 ``tracepoint passcount'' also accepts a range of tracepoints.
5728 * ``apropos'' command added.
5730 The ``apropos'' command searches through command names and
5731 documentation strings, printing out matches, making it much easier to
5732 try to find a command that does what you are looking for.
5736 A new machine oriented interface (MI) has been added to GDB. This
5737 interface is designed for debug environments running GDB as a separate
5738 process. This is part of the long term libGDB project. See the
5739 "GDB/MI" chapter of the GDB manual for further information. It can be
5740 enabled by configuring with:
5742 .../configure --enable-gdbmi
5744 *** Changes in GDB-4.18:
5746 * New native configurations
5748 HP-UX 10.20 hppa*-*-hpux10.20
5749 HP-UX 11.x hppa*-*-hpux11.0*
5750 M68K GNU/Linux m68*-*-linux*
5754 Fujitsu FR30 fr30-*-elf*
5755 Intel StrongARM strongarm-*-*
5756 Mitsubishi D30V d30v-*-*
5758 * OBSOLETE configurations
5760 Gould PowerNode, NP1 np1-*-*, pn-*-*
5762 Configurations that have been declared obsolete will be commented out,
5763 but the code will be left in place. If there is no activity to revive
5764 these configurations before the next release of GDB, the sources will
5765 be permanently REMOVED.
5769 As a compatibility experiment, GDB's source files buildsym.h and
5770 buildsym.c have been converted to pure standard C, no longer
5771 containing any K&R compatibility code. We believe that all systems in
5772 use today either come with a standard C compiler, or have a GCC port
5773 available. If this is not true, please report the affected
5774 configuration to bug-gdb@gnu.org immediately. See the README file for
5775 information about getting a standard C compiler if you don't have one
5780 GDB now uses readline 2.2.
5782 * set extension-language
5784 You can now control the mapping between filename extensions and source
5785 languages by using the `set extension-language' command. For instance,
5786 you can ask GDB to treat .c files as C++ by saying
5787 set extension-language .c c++
5788 The command `info extensions' lists all of the recognized extensions
5789 and their associated languages.
5791 * Setting processor type for PowerPC and RS/6000
5793 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5794 you can use the `set processor' command to specify what variant of the
5795 PowerPC family you are debugging. The command
5799 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5800 following PowerPC and RS6000 variants:
5802 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5803 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5805 403GC IBM PowerPC 403GC
5806 505 Motorola PowerPC 505
5807 860 Motorola PowerPC 860 or 850
5808 601 Motorola PowerPC 601
5809 602 Motorola PowerPC 602
5810 603 Motorola/IBM PowerPC 603 or 603e
5811 604 Motorola PowerPC 604 or 604e
5812 750 Motorola/IBM PowerPC 750 or 750
5814 At the moment, this command just tells GDB what to name the
5815 special-purpose processor registers. Since almost all the affected
5816 registers are inaccessible to user-level programs, this command is
5817 only useful for remote debugging in its present form.
5821 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5822 more extensive support for HP-UX. Added features include shared
5823 library support, kernel threads and hardware watchpoints for 11.00,
5824 support for HP's ANSI C and C++ compilers, and a compatibility mode
5825 for xdb and dbx commands.
5829 HP's donation includes the new concept of catchpoints, which is a
5830 generalization of the old catch command. On HP-UX, it is now possible
5831 to catch exec, fork, and vfork, as well as library loading.
5833 This means that the existing catch command has changed; its first
5834 argument now specifies the type of catch to be set up. See the
5835 output of "help catch" for a list of catchpoint types.
5837 * Debugging across forks
5839 On HP-UX, you can choose which process to debug when a fork() happens
5844 HP has donated a curses-based terminal user interface (TUI). To get
5845 it, build with --enable-tui. Although this can be enabled for any
5846 configuration, at present it only works for native HP debugging.
5848 * GDB remote protocol additions
5850 A new protocol packet 'X' that writes binary data is now available.
5851 Default behavior is to try 'X', then drop back to 'M' if the stub
5852 fails to respond. The settable variable `remotebinarydownload'
5853 allows explicit control over the use of 'X'.
5855 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5856 full 64-bit address. The command
5858 set remoteaddresssize 32
5860 can be used to revert to the old behaviour. For existing remote stubs
5861 the change should not be noticed, as the additional address information
5864 In order to assist in debugging stubs, you may use the maintenance
5865 command `packet' to send any text string to the stub. For instance,
5867 maint packet heythere
5869 sends the packet "$heythere#<checksum>". Note that it is very easy to
5870 disrupt a debugging session by sending the wrong packet at the wrong
5873 The compare-sections command allows you to compare section data on the
5874 target to what is in the executable file without uploading or
5875 downloading, by comparing CRC checksums.
5877 * Tracing can collect general expressions
5879 You may now collect general expressions at tracepoints. This requires
5880 further additions to the target-side stub; see tracepoint.c and
5881 doc/agentexpr.texi for further details.
5883 * mask-address variable for Mips
5885 For Mips targets, you may control the zeroing of the upper 32 bits of
5886 a 64-bit address by entering `set mask-address on'. This is mainly
5887 of interest to users of embedded R4xxx and R5xxx processors.
5889 * Higher serial baud rates
5891 GDB's serial code now allows you to specify baud rates 57600, 115200,
5892 230400, and 460800 baud. (Note that your host system may not be able
5893 to achieve all of these rates.)
5897 The i960 configuration now includes an initial implementation of a
5898 builtin simulator, contributed by Jim Wilson.
5901 *** Changes in GDB-4.17:
5903 * New native configurations
5905 Alpha GNU/Linux alpha*-*-linux*
5906 Unixware 2.x i[3456]86-unixware2*
5907 Irix 6.x mips*-sgi-irix6*
5908 PowerPC GNU/Linux powerpc-*-linux*
5909 PowerPC Solaris powerpcle-*-solaris*
5910 Sparc GNU/Linux sparc-*-linux*
5911 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5915 Argonaut Risc Chip (ARC) arc-*-*
5916 Hitachi H8/300S h8300*-*-*
5917 Matsushita MN10200 w/simulator mn10200-*-*
5918 Matsushita MN10300 w/simulator mn10300-*-*
5919 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5920 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5921 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5922 Mitsubishi D10V w/simulator d10v-*-*
5923 Mitsubishi M32R/D w/simulator m32r-*-elf*
5924 Tsqware Sparclet sparclet-*-*
5925 NEC V850 w/simulator v850-*-*
5927 * New debugging protocols
5929 ARM with RDI protocol arm*-*-*
5930 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5931 DDB and LSI variants of PMON protocol mips*-*-*
5932 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5933 PowerPC with SDS protocol powerpc{,le}-*-eabi
5934 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5938 All configurations can now understand and use the DWARF 2 debugging
5939 format. The choice is automatic, if the symbol file contains DWARF 2
5944 GDB now includes basic Java language support. This support is
5945 only useful with Java compilers that produce native machine code.
5947 * solib-absolute-prefix and solib-search-path
5949 For SunOS and SVR4 shared libraries, you may now set the prefix for
5950 loading absolute shared library symbol files, and the search path for
5951 locating non-absolute shared library symbol files.
5953 * Live range splitting
5955 GDB can now effectively debug code for which GCC has performed live
5956 range splitting as part of its optimization. See gdb/doc/LRS for
5957 more details on the expected format of the stabs information.
5961 GDB's support for the GNU Hurd, including thread debugging, has been
5962 updated to work with current versions of the Hurd.
5966 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5967 instruction set. ARM GDB automatically detects when Thumb
5968 instructions are in use, and adjusts disassembly and backtracing
5973 GDB's MIPS target configurations now handle the MIP16 16-bit
5978 GDB now includes support for overlays; if an executable has been
5979 linked such that multiple sections are based at the same address, GDB
5980 will decide which section to use for symbolic info. You can choose to
5981 control the decision manually, using overlay commands, or implement
5982 additional target-side support and use "overlay load-target" to bring
5983 in the overlay mapping. Do "help overlay" for more detail.
5987 The command "info symbol <address>" displays information about
5988 the symbol at the specified address.
5992 The standard remote protocol now includes an extension that allows
5993 asynchronous collection and display of trace data. This requires
5994 extensive support in the target-side debugging stub. Tracing mode
5995 includes a new interaction mode in GDB and new commands: see the
5996 file tracepoint.c for more details.
6000 Configurations for embedded MIPS now include a simulator contributed
6001 by Cygnus Solutions. The simulator supports the instruction sets
6002 of most MIPS variants.
6006 Sparc configurations may now include the ERC32 simulator contributed
6007 by the European Space Agency. The simulator is not built into
6008 Sparc targets by default; configure with --enable-sim to include it.
6012 For target configurations that may include multiple variants of a
6013 basic architecture (such as MIPS and SH), you may now set the
6014 architecture explicitly. "set arch" sets, "info arch" lists
6015 the possible architectures.
6017 *** Changes in GDB-4.16:
6019 * New native configurations
6021 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6022 M68K NetBSD m68k-*-netbsd*
6023 PowerPC AIX 4.x powerpc-*-aix*
6024 PowerPC MacOS powerpc-*-macos*
6025 PowerPC Windows NT powerpcle-*-cygwin32
6026 RS/6000 AIX 4.x rs6000-*-aix4*
6030 ARM with RDP protocol arm-*-*
6031 I960 with MON960 i960-*-coff
6032 MIPS VxWorks mips*-*-vxworks*
6033 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6034 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6036 Matra Sparclet sparclet-*-*
6040 The powerpc-eabi configuration now includes the PSIM simulator,
6041 contributed by Andrew Cagney, with assistance from Mike Meissner.
6042 PSIM is a very elaborate model of the PowerPC, including not only
6043 basic instruction set execution, but also details of execution unit
6044 performance and I/O hardware. See sim/ppc/README for more details.
6048 GDB now works with Solaris 2.5.
6050 * Windows 95/NT native
6052 GDB will now work as a native debugger on Windows 95 and Windows NT.
6053 To build it from source, you must use the "gnu-win32" environment,
6054 which uses a DLL to emulate enough of Unix to run the GNU tools.
6055 Further information, binaries, and sources are available at
6056 ftp.cygnus.com, under pub/gnu-win32.
6058 * dont-repeat command
6060 If a user-defined command includes the command `dont-repeat', then the
6061 command will not be repeated if the user just types return. This is
6062 useful if the command is time-consuming to run, so that accidental
6063 extra keystrokes don't run the same command many times.
6065 * Send break instead of ^C
6067 The standard remote protocol now includes an option to send a break
6068 rather than a ^C to the target in order to interrupt it. By default,
6069 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6071 * Remote protocol timeout
6073 The standard remote protocol includes a new variable `remotetimeout'
6074 that allows you to set the number of seconds before GDB gives up trying
6075 to read from the target. The default value is 2.
6077 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6079 By default GDB will automatically keep track of objects as they are
6080 loaded and unloaded by the dynamic linker. By using the command `set
6081 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6082 when shared library events occur, thus allowing you to set breakpoints
6083 in shared libraries which are explicitly loaded by the inferior.
6085 Note this feature does not work on hpux8. On hpux9 you must link
6086 /usr/lib/end.o into your program. This feature should work
6087 automatically on hpux10.
6089 * Irix 5.x hardware watchpoint support
6091 Irix 5 configurations now support the use of hardware watchpoints.
6093 * Mips protocol "SYN garbage limit"
6095 When debugging a Mips target using the `target mips' protocol, you
6096 may set the number of characters that GDB will ignore by setting
6097 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6098 every character. The default value is 1050.
6100 * Recording and replaying remote debug sessions
6102 If you set `remotelogfile' to the name of a file, gdb will write to it
6103 a recording of a remote debug session. This recording may then be
6104 replayed back to gdb using "gdbreplay". See gdbserver/README for
6105 details. This is useful when you have a problem with GDB while doing
6106 remote debugging; you can make a recording of the session and send it
6107 to someone else, who can then recreate the problem.
6109 * Speedups for remote debugging
6111 GDB includes speedups for downloading and stepping MIPS systems using
6112 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6113 and more efficient S-record downloading.
6115 * Memory use reductions and statistics collection
6117 GDB now uses less memory and reports statistics about memory usage.
6118 Try the `maint print statistics' command, for example.
6120 *** Changes in GDB-4.15:
6122 * Psymtabs for XCOFF
6124 The symbol reader for AIX GDB now uses partial symbol tables. This
6125 can greatly improve startup time, especially for large executables.
6127 * Remote targets use caching
6129 Remote targets now use a data cache to speed up communication with the
6130 remote side. The data cache could lead to incorrect results because
6131 it doesn't know about volatile variables, thus making it impossible to
6132 debug targets which use memory mapped I/O devices. `set remotecache
6133 off' turns the the data cache off.
6135 * Remote targets may have threads
6137 The standard remote protocol now includes support for multiple threads
6138 in the target system, using new protocol commands 'H' and 'T'. See
6139 gdb/remote.c for details.
6143 If GDB is configured with `--enable-netrom', then it will include
6144 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6145 acts as though it is a bank of ROM on the target board, but you can
6146 write into it over the network. GDB's support consists only of
6147 support for fast loading into the emulated ROM; to debug, you must use
6148 another protocol, such as standard remote protocol. The usual
6149 sequence is something like
6151 target nrom <netrom-hostname>
6153 target remote <netrom-hostname>:1235
6157 GDB now includes support for the Apple Macintosh, as a host only. It
6158 may be run as either an MPW tool or as a standalone application, and
6159 it can debug through the serial port. All the usual GDB commands are
6160 available, but to the target command, you must supply "serial" as the
6161 device type instead of "/dev/ttyXX". See mpw-README in the main
6162 directory for more information on how to build. The MPW configuration
6163 scripts */mpw-config.in support only a few targets, and only the
6164 mips-idt-ecoff target has been tested.
6168 GDB configuration now uses autoconf. This is not user-visible,
6169 but does simplify configuration and building.
6173 GDB now supports hpux10.
6175 *** Changes in GDB-4.14:
6177 * New native configurations
6179 x86 FreeBSD i[345]86-*-freebsd
6180 x86 NetBSD i[345]86-*-netbsd
6181 NS32k NetBSD ns32k-*-netbsd
6182 Sparc NetBSD sparc-*-netbsd
6186 A29K VxWorks a29k-*-vxworks
6187 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6188 CPU32 EST-300 emulator m68*-*-est*
6189 PowerPC ELF powerpc-*-elf
6192 * Alpha OSF/1 support for procfs
6194 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6195 possible to attach to running processes. As the mounting of the /proc
6196 filesystem is optional on the Alpha, GDB automatically determines
6197 the availability of /proc during startup. This can lead to problems
6198 if /proc is unmounted after GDB has been started.
6200 * Arguments to user-defined commands
6202 User commands may accept up to 10 arguments separated by whitespace.
6203 Arguments are accessed within the user command via $arg0..$arg9. A
6206 print $arg0 + $arg1 + $arg2
6208 To execute the command use:
6211 Defines the command "adder" which prints the sum of its three arguments.
6212 Note the arguments are text substitutions, so they may reference variables,
6213 use complex expressions, or even perform inferior function calls.
6215 * New `if' and `while' commands
6217 This makes it possible to write more sophisticated user-defined
6218 commands. Both commands take a single argument, which is the
6219 expression to evaluate, and must be followed by the commands to
6220 execute, one per line, if the expression is nonzero, the list being
6221 terminated by the word `end'. The `if' command list may include an
6222 `else' word, which causes the following commands to be executed only
6223 if the expression is zero.
6225 * Fortran source language mode
6227 GDB now includes partial support for Fortran 77. It will recognize
6228 Fortran programs and can evaluate a subset of Fortran expressions, but
6229 variables and functions may not be handled correctly. GDB will work
6230 with G77, but does not yet know much about symbols emitted by other
6233 * Better HPUX support
6235 Most debugging facilities now work on dynamic executables for HPPAs
6236 running hpux9 or later. You can attach to running dynamically linked
6237 processes, but by default the dynamic libraries will be read-only, so
6238 for instance you won't be able to put breakpoints in them. To change
6239 that behavior do the following before running the program:
6245 This will cause the libraries to be mapped private and read-write.
6246 To revert to the normal behavior, do this:
6252 You cannot set breakpoints or examine data in the library until after
6253 the library is loaded if the function/data symbols do not have
6256 GDB can now also read debug symbols produced by the HP C compiler on
6257 HPPAs (sorry, no C++, Fortran or 68k support).
6259 * Target byte order now dynamically selectable
6261 You can choose which byte order to use with a target system, via the
6262 commands "set endian big" and "set endian little", and you can see the
6263 current setting by using "show endian". You can also give the command
6264 "set endian auto", in which case GDB will use the byte order
6265 associated with the executable. Currently, only embedded MIPS
6266 configurations support dynamic selection of target byte order.
6268 * New DOS host serial code
6270 This version uses DPMI interrupts to handle buffered I/O, so you
6271 no longer need to run asynctsr when debugging boards connected to
6274 *** Changes in GDB-4.13:
6276 * New "complete" command
6278 This lists all the possible completions for the rest of the line, if it
6279 were to be given as a command itself. This is intended for use by emacs.
6281 * Trailing space optional in prompt
6283 "set prompt" no longer adds a space for you after the prompt you set. This
6284 allows you to set a prompt which ends in a space or one that does not.
6286 * Breakpoint hit counts
6288 "info break" now displays a count of the number of times the breakpoint
6289 has been hit. This is especially useful in conjunction with "ignore"; you
6290 can ignore a large number of breakpoint hits, look at the breakpoint info
6291 to see how many times the breakpoint was hit, then run again, ignoring one
6292 less than that number, and this will get you quickly to the last hit of
6295 * Ability to stop printing at NULL character
6297 "set print null-stop" will cause GDB to stop printing the characters of
6298 an array when the first NULL is encountered. This is useful when large
6299 arrays actually contain only short strings.
6301 * Shared library breakpoints
6303 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6304 breakpoints in shared libraries before the executable is run.
6306 * Hardware watchpoints
6308 There is a new hardware breakpoint for the watch command for sparclite
6309 targets. See gdb/sparclite/hw_breakpoint.note.
6311 Hardware watchpoints are also now supported under GNU/Linux.
6315 Annotations have been added. These are for use with graphical interfaces,
6316 and are still experimental. Currently only gdba.el uses these.
6318 * Improved Irix 5 support
6320 GDB now works properly with Irix 5.2.
6322 * Improved HPPA support
6324 GDB now works properly with the latest GCC and GAS.
6326 * New native configurations
6328 Sequent PTX4 i[34]86-sequent-ptx4
6329 HPPA running OSF/1 hppa*-*-osf*
6330 Atari TT running SVR4 m68*-*-sysv4*
6331 RS/6000 LynxOS rs6000-*-lynxos*
6335 OS/9000 i[34]86-*-os9k
6336 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6339 * Hitachi SH7000 and E7000-PC ICE support
6341 There is now support for communicating with the Hitachi E7000-PC ICE.
6342 This is available automatically when GDB is configured for the SH.
6346 As usual, a variety of small fixes and improvements, both generic
6347 and configuration-specific. See the ChangeLog for more detail.
6349 *** Changes in GDB-4.12:
6351 * Irix 5 is now supported
6355 GDB-4.12 on the HPPA has a number of changes which make it unable
6356 to debug the output from the currently released versions of GCC and
6357 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6358 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6359 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6362 *** Changes in GDB-4.11:
6364 * User visible changes:
6368 The "set remotedebug" option is now consistent between the mips remote
6369 target, remote targets using the gdb-specific protocol, UDI (AMD's
6370 debug protocol for the 29k) and the 88k bug monitor. It is now an
6371 integer specifying a debug level (normally 0 or 1, but 2 means more
6372 debugging info for the mips target).
6374 * DEC Alpha native support
6376 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6377 debug info, but GDB works fairly well with the DEC compiler and should
6378 work with a future GCC release. See the README file for a few
6379 Alpha-specific notes.
6381 * Preliminary thread implementation
6383 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6385 * LynxOS native and target support for 386
6387 This release has been hosted on LynxOS 2.2, and also can be configured
6388 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6391 * Improvements in C++ mangling/demangling.
6393 This release has much better g++ debugging, specifically in name
6394 mangling/demangling, virtual function calls, print virtual table,
6395 call methods, ...etc.
6397 *** Changes in GDB-4.10:
6399 * User visible changes:
6401 Remote debugging using the GDB-specific (`target remote') protocol now
6402 supports the `load' command. This is only useful if you have some
6403 other way of getting the stub to the target system, and you can put it
6404 somewhere in memory where it won't get clobbered by the download.
6406 Filename completion now works.
6408 When run under emacs mode, the "info line" command now causes the
6409 arrow to point to the line specified. Also, "info line" prints
6410 addresses in symbolic form (as well as hex).
6412 All vxworks based targets now support a user settable option, called
6413 vxworks-timeout. This option represents the number of seconds gdb
6414 should wait for responses to rpc's. You might want to use this if
6415 your vxworks target is, perhaps, a slow software simulator or happens
6416 to be on the far side of a thin network line.
6420 This release contains support for using a DEC alpha as a GDB host for
6421 cross debugging. Native alpha debugging is not supported yet.
6424 *** Changes in GDB-4.9:
6428 This is the first GDB release which is accompanied by a matching testsuite.
6429 The testsuite requires installation of dejagnu, which should be available
6430 via ftp from most sites that carry GNU software.
6434 'Cfront' style demangling has had its name changed to 'ARM' style, to
6435 emphasize that it was written from the specifications in the C++ Annotated
6436 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6437 disclaimers, it still generated too much confusion with users attempting to
6438 use gdb with AT&T cfront.
6442 GDB now uses a standard remote interface to a simulator library.
6443 So far, the library contains simulators for the Zilog Z8001/2, the
6444 Hitachi H8/300, H8/500 and Super-H.
6446 * New targets supported
6448 H8/300 simulator h8300-hitachi-hms or h8300hms
6449 H8/500 simulator h8500-hitachi-hms or h8500hms
6450 SH simulator sh-hitachi-hms or sh
6451 Z8000 simulator z8k-zilog-none or z8ksim
6452 IDT MIPS board over serial line mips-idt-ecoff
6454 Cross-debugging to GO32 targets is supported. It requires a custom
6455 version of the i386-stub.c module which is integrated with the
6456 GO32 memory extender.
6458 * New remote protocols
6460 MIPS remote debugging protocol.
6462 * New source languages supported
6464 This version includes preliminary support for Chill, a Pascal like language
6465 used by telecommunications companies. Chill support is also being integrated
6466 into the GNU compiler, but we don't know when it will be publically available.
6469 *** Changes in GDB-4.8:
6471 * HP Precision Architecture supported
6473 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6474 version of this support was available as a set of patches from the
6475 University of Utah. GDB does not support debugging of programs
6476 compiled with the HP compiler, because HP will not document their file
6477 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6478 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6480 Many problems in the preliminary version have been fixed.
6482 * Faster and better demangling
6484 We have improved template demangling and fixed numerous bugs in the GNU style
6485 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6486 character types (wchar_t) are now supported. Demangling of each symbol is now
6487 only done once, and is cached when the symbol table for a file is read in.
6488 This results in a small increase in memory usage for C programs, a moderate
6489 increase in memory usage for C++ programs, and a fantastic speedup in
6492 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6493 from the specifications in the Annotated Reference Manual, which AT&T's
6494 compiler does not actually implement.
6496 * G++ multiple inheritance compiler problem
6498 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6499 inheritance lattices was reworked to properly discover ambiguities. We
6500 recently found an example which causes this new algorithm to fail in a
6501 very subtle way, producing bad debug information for those classes.
6502 The file 'gcc.patch' (in this directory) can be applied to gcc to
6503 circumvent the problem. A future GCC release will contain a complete
6506 The previous G++ debug info problem (mentioned below for the gdb-4.7
6507 release) is fixed in gcc version 2.3.2.
6509 * Improved configure script
6511 The `configure' script will now attempt to guess your system type if
6512 you don't supply a host system type. The old scheme of supplying a
6513 host system triplet is preferable over using this. All the magic is
6514 done in the new `config.guess' script. Examine it for details.
6516 We have also brought our configure script much more in line with the FSF's
6517 version. It now supports the --with-xxx options. In particular,
6518 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6519 The resulting GDB will not be able to read arbitrary object file formats --
6520 only the format ``expected'' to be used on the configured target system.
6521 We hope to make this the default in a future release.
6523 * Documentation improvements
6525 There's new internal documentation on how to modify GDB, and how to
6526 produce clean changes to the code. We implore people to read it
6527 before submitting changes.
6529 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6530 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6531 `info' files are also provided. To build `info' files from scratch,
6532 you will need the latest `makeinfo' release, which will be available in
6533 a future texinfo-X.Y release.
6535 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6536 We're not sure exactly which versions have this problem, but it has
6537 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6538 or better. If that isn't possible, there is a patch in
6539 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6540 around this problem.
6544 GDB now supports array constants that can be used in expressions typed in by
6545 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6546 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6549 The new directory `gdb/sparclite' contains a program that demonstrates
6550 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6552 * New native hosts supported
6554 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6555 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6557 * New targets supported
6559 AMD 29k family via UDI a29k-amd-udi or udi29k
6561 * New file formats supported
6563 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6564 HPUX core files, and SCO 3.2v2 core files.
6568 Attaching to processes now works again; thanks for the many bug reports.
6570 We have also stomped on a bunch of core dumps caused by
6571 printf_filtered("%s") problems.
6573 We eliminated a copyright problem on the rpc and ptrace header files
6574 for VxWorks, which was discovered at the last minute during the 4.7
6575 release. You should now be able to build a VxWorks GDB.
6577 You can now interrupt gdb while an attached process is running. This
6578 will cause the attached process to stop, and give control back to GDB.
6580 We fixed problems caused by using too many file descriptors
6581 for reading symbols from object files and libraries. This was
6582 especially a problem for programs that used many (~100) shared
6585 The `step' command now only enters a subroutine if there is line number
6586 information for the subroutine. Otherwise it acts like the `next'
6587 command. Previously, `step' would enter subroutines if there was
6588 any debugging information about the routine. This avoids problems
6589 when using `cc -g1' on MIPS machines.
6591 * Internal improvements
6593 GDB's internal interfaces have been improved to make it easier to support
6594 debugging of multiple languages in the future.
6596 GDB now uses a common structure for symbol information internally.
6597 Minimal symbols (derived from linkage symbols in object files), partial
6598 symbols (from a quick scan of debug information), and full symbols
6599 contain a common subset of information, making it easier to write
6600 shared code that handles any of them.
6602 * New command line options
6604 We now accept --silent as an alias for --quiet.
6608 The memory-mapped-malloc library is now licensed under the GNU Library
6609 General Public License.
6611 *** Changes in GDB-4.7:
6613 * Host/native/target split
6615 GDB has had some major internal surgery to untangle the support for
6616 hosts and remote targets. Now, when you configure GDB for a remote
6617 target, it will no longer load in all of the support for debugging
6618 local programs on the host. When fully completed and tested, this will
6619 ensure that arbitrary host/target combinations are possible.
6621 The primary conceptual shift is to separate the non-portable code in
6622 GDB into three categories. Host specific code is required any time GDB
6623 is compiled on that host, regardless of the target. Target specific
6624 code relates to the peculiarities of the target, but can be compiled on
6625 any host. Native specific code is everything else: it can only be
6626 built when the host and target are the same system. Child process
6627 handling and core file support are two common `native' examples.
6629 GDB's use of /proc for controlling Unix child processes is now cleaner.
6630 It has been split out into a single module under the `target_ops' vector,
6631 plus two native-dependent functions for each system that uses /proc.
6633 * New hosts supported
6635 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6636 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6637 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6639 * New targets supported
6641 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6642 68030 and CPU32 m68030-*-*, m68332-*-*
6644 * New native hosts supported
6646 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6647 (386bsd is not well tested yet)
6648 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6650 * New file formats supported
6652 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6653 supports reading of `a.out.adobe' object files, which are an a.out
6654 format extended with minimal information about multiple sections.
6658 `show copying' is the same as the old `info copying'.
6659 `show warranty' is the same as `info warrantee'.
6660 These were renamed for consistency. The old commands continue to work.
6662 `info handle' is a new alias for `info signals'.
6664 You can now define pre-command hooks, which attach arbitrary command
6665 scripts to any command. The commands in the hook will be executed
6666 prior to the user's command. You can also create a hook which will be
6667 executed whenever the program stops. See gdb.texinfo.
6671 We now deal with Cfront style name mangling, and can even extract type
6672 info from mangled symbols. GDB can automatically figure out which
6673 symbol mangling style your C++ compiler uses.
6675 Calling of methods and virtual functions has been improved as well.
6679 The crash that occured when debugging Sun Ansi-C compiled binaries is
6680 fixed. This was due to mishandling of the extra N_SO stabs output
6683 We also finally got Ultrix 4.2 running in house, and fixed core file
6684 support, with help from a dozen people on the net.
6686 John M. Farrell discovered that the reason that single-stepping was so
6687 slow on all of the Mips based platforms (primarily SGI and DEC) was
6688 that we were trying to demangle and lookup a symbol used for internal
6689 purposes on every instruction that was being stepped through. Changing
6690 the name of that symbol so that it couldn't be mistaken for a C++
6691 mangled symbol sped things up a great deal.
6693 Rich Pixley sped up symbol lookups in general by getting much smarter
6694 about when C++ symbol mangling is necessary. This should make symbol
6695 completion (TAB on the command line) much faster. It's not as fast as
6696 we'd like, but it's significantly faster than gdb-4.6.
6700 A new user controllable variable 'call_scratch_address' can
6701 specify the location of a scratch area to be used when GDB
6702 calls a function in the target. This is necessary because the
6703 usual method of putting the scratch area on the stack does not work
6704 in systems that have separate instruction and data spaces.
6706 We integrated changes to support the 29k UDI (Universal Debugger
6707 Interface), but discovered at the last minute that we didn't have all
6708 of the appropriate copyright paperwork. We are working with AMD to
6709 resolve this, and hope to have it available soon.
6713 We have sped up the remote serial line protocol, especially for targets
6714 with lots of registers. It now supports a new `expedited status' ('T')
6715 message which can be used in place of the existing 'S' status message.
6716 This allows the remote stub to send only the registers that GDB
6717 needs to make a quick decision about single-stepping or conditional
6718 breakpoints, eliminating the need to fetch the entire register set for
6719 each instruction being stepped through.
6721 The GDB remote serial protocol now implements a write-through cache for
6722 registers, only re-reading the registers if the target has run.
6724 There is also a new remote serial stub for SPARC processors. You can
6725 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6726 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6727 processor with a serial port.
6731 Configure.in files have become much easier to read and modify. A new
6732 `table driven' format makes it more obvious what configurations are
6733 supported, and what files each one uses.
6737 There is a new opcodes library which will eventually contain all of the
6738 disassembly routines and opcode tables. At present, it only contains
6739 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6740 disassembler (binutils/objdump) to share these routines.
6742 The libiberty library is now copylefted under the GNU Library General
6743 Public License. This allows more liberal use, and was done so libg++
6744 can use it. This makes no difference to GDB, since the Library License
6745 grants all the rights from the General Public License.
6749 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6750 reference to the stabs symbol info used by the debugger. It is (as far
6751 as we know) the only published document on this fascinating topic. We
6752 encourage you to read it, compare it to the stabs information on your
6753 system, and send improvements on the document in general (to
6754 bug-gdb@prep.ai.mit.edu).
6756 And, of course, many bugs have been fixed.
6759 *** Changes in GDB-4.6:
6761 * Better support for C++ function names
6763 GDB now accepts as input the "demangled form" of C++ overloaded function
6764 names and member function names, and can do command completion on such names
6765 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6766 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6767 Make use of command completion, it is your friend.
6769 GDB also now accepts a variety of C++ mangled symbol formats. They are
6770 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6771 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6772 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6773 for the list of formats.
6775 * G++ symbol mangling problem
6777 Recent versions of gcc have a bug in how they emit debugging information for
6778 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6779 directory) can be applied to gcc to fix the problem. Alternatively, if you
6780 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6781 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6782 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6785 * New 'maintenance' command
6787 All of the commands related to hacking GDB internals have been moved out of
6788 the main command set, and now live behind the 'maintenance' command. This
6789 can also be abbreviated as 'mt'. The following changes were made:
6791 dump-me -> maintenance dump-me
6792 info all-breakpoints -> maintenance info breakpoints
6793 printmsyms -> maintenance print msyms
6794 printobjfiles -> maintenance print objfiles
6795 printpsyms -> maintenance print psymbols
6796 printsyms -> maintenance print symbols
6798 The following commands are new:
6800 maintenance demangle Call internal GDB demangler routine to
6801 demangle a C++ link name and prints the result.
6802 maintenance print type Print a type chain for a given symbol
6804 * Change to .gdbinit file processing
6806 We now read the $HOME/.gdbinit file before processing the argv arguments
6807 (e.g. reading symbol files or core files). This allows global parameters to
6808 be set, which will apply during the symbol reading. The ./.gdbinit is still
6809 read after argv processing.
6811 * New hosts supported
6813 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6815 GNU/Linux support i386-unknown-linux or linux
6817 We are also including code to support the HP/PA running BSD and HPUX. This
6818 is almost guaranteed not to work, as we didn't have time to test or build it
6819 for this release. We are including it so that the more adventurous (or
6820 masochistic) of you can play with it. We also had major problems with the
6821 fact that the compiler that we got from HP doesn't support the -g option.
6824 * New targets supported
6826 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6828 * More smarts about finding #include files
6830 GDB now remembers the compilation directory for all include files, and for
6831 all files from which C is generated (like yacc and lex sources). This
6832 greatly improves GDB's ability to find yacc/lex sources, and include files,
6833 especially if you are debugging your program from a directory different from
6834 the one that contains your sources.
6836 We also fixed a bug which caused difficulty with listing and setting
6837 breakpoints in include files which contain C code. (In the past, you had to
6838 try twice in order to list an include file that you hadn't looked at before.)
6840 * Interesting infernals change
6842 GDB now deals with arbitrary numbers of sections, where the symbols for each
6843 section must be relocated relative to that section's landing place in the
6844 target's address space. This work was needed to support ELF with embedded
6845 stabs used by Solaris-2.0.
6847 * Bug fixes (of course!)
6849 There have been loads of fixes for the following things:
6850 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6851 i960, stabs, DOS(GO32), procfs, etc...
6853 See the ChangeLog for details.
6855 *** Changes in GDB-4.5:
6857 * New machines supported (host and target)
6859 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6861 SGI Irix-4.x mips-sgi-irix4 or iris4
6863 * New malloc package
6865 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6866 Mmalloc is capable of handling mutiple heaps of memory. It is also
6867 capable of saving a heap to a file, and then mapping it back in later.
6868 This can be used to greatly speedup the startup of GDB by using a
6869 pre-parsed symbol table which lives in a mmalloc managed heap. For
6870 more details, please read mmalloc/mmalloc.texi.
6874 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6875 'help info proc' for details.
6877 * MIPS ecoff symbol table format
6879 The code that reads MIPS symbol table format is now supported on all hosts.
6880 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6883 * File name changes for MS-DOS
6885 Many files in the config directories have been renamed to make it easier to
6886 support GDB on MS-DOSe systems (which have very restrictive file name
6887 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6888 environment) is close to working but has some remaining problems. Note
6889 that debugging of DOS programs is not supported, due to limitations
6890 in the ``operating system'', but it can be used to host cross-debugging.
6892 * Cross byte order fixes
6894 Many fixes have been made to support cross debugging of Sparc and MIPS
6895 targets from hosts whose byte order differs.
6897 * New -mapped and -readnow options
6899 If memory-mapped files are available on your system through the 'mmap'
6900 system call, you can use the -mapped option on the `file' or
6901 `symbol-file' commands to cause GDB to write the symbols from your
6902 program into a reusable file. If the program you are debugging is
6903 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6904 Future GDB debugging sessions will notice the presence of this file,
6905 and will quickly map in symbol information from it, rather than reading
6906 the symbol table from the executable program. Using the '-mapped'
6907 option in a GDB `file' or `symbol-file' command has the same effect as
6908 starting GDB with the '-mapped' command-line option.
6910 You can cause GDB to read the entire symbol table immediately by using
6911 the '-readnow' option with any of the commands that load symbol table
6912 information (or on the GDB command line). This makes the command
6913 slower, but makes future operations faster.
6915 The -mapped and -readnow options are typically combined in order to
6916 build a `fred.syms' file that contains complete symbol information.
6917 A simple GDB invocation to do nothing but build a `.syms' file for future
6920 gdb -batch -nx -mapped -readnow programname
6922 The `.syms' file is specific to the host machine on which GDB is run.
6923 It holds an exact image of GDB's internal symbol table. It cannot be
6924 shared across multiple host platforms.
6926 * longjmp() handling
6928 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6929 siglongjmp() without losing control. This feature has not yet been ported to
6930 all systems. It currently works on many 386 platforms, all MIPS-based
6931 platforms (SGI, DECstation, etc), and Sun3/4.
6935 Preliminary work has been put in to support the new Solaris OS from Sun. At
6936 this time, it can control and debug processes, but it is not capable of
6941 As always, many many bug fixes. The major areas were with g++, and mipsread.
6942 People using the MIPS-based platforms should experience fewer mysterious
6943 crashes and trashed symbol tables.
6945 *** Changes in GDB-4.4:
6947 * New machines supported (host and target)
6949 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6951 BSD Reno on Vax vax-dec-bsd
6952 Ultrix on Vax vax-dec-ultrix
6954 * New machines supported (target)
6956 AMD 29000 embedded, using EBMON a29k-none-none
6960 GDB continues to improve its handling of C++. `References' work better.
6961 The demangler has also been improved, and now deals with symbols mangled as
6962 per the Annotated C++ Reference Guide.
6964 GDB also now handles `stabs' symbol information embedded in MIPS
6965 `ecoff' symbol tables. Since the ecoff format was not easily
6966 extensible to handle new languages such as C++, this appeared to be a
6967 good way to put C++ debugging info into MIPS binaries. This option
6968 will be supported in the GNU C compiler, version 2, when it is
6971 * New features for SVR4
6973 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6974 shared libraries. Debugging dynamically linked programs should present
6975 only minor differences from debugging statically linked programs.
6977 The `info proc' command will print out information about any process
6978 on an SVR4 system (including the one you are debugging). At the moment,
6979 it prints the address mappings of the process.
6981 If you bring up GDB on another SVR4 system, please send mail to
6982 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6984 * Better dynamic linking support in SunOS
6986 Reading symbols from shared libraries which contain debugging symbols
6987 now works properly. However, there remain issues such as automatic
6988 skipping of `transfer vector' code during function calls, which
6989 make it harder to debug code in a shared library, than to debug the
6990 same code linked statically.
6994 GDB is now using the latest `getopt' routines from the FSF. This
6995 version accepts the -- prefix for options with long names. GDB will
6996 continue to accept the old forms (-option and +option) as well.
6997 Various single letter abbreviations for options have been explicity
6998 added to the option table so that they won't get overshadowed in the
6999 future by other options that begin with the same letter.
7003 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7004 Many assorted bugs have been handled. Many more remain to be handled.
7005 See the various ChangeLog files (primarily in gdb and bfd) for details.
7008 *** Changes in GDB-4.3:
7010 * New machines supported (host and target)
7012 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7013 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7014 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7016 * Almost SCO Unix support
7018 We had hoped to support:
7019 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7020 (except for core file support), but we discovered very late in the release
7021 that it has problems with process groups that render gdb unusable. Sorry
7022 about that. I encourage people to fix it and post the fixes.
7024 * Preliminary ELF and DWARF support
7026 GDB can read ELF object files on System V Release 4, and can handle
7027 debugging records for C, in DWARF format, in ELF files. This support
7028 is preliminary. If you bring up GDB on another SVR4 system, please
7029 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7034 GDB now uses the latest `readline' library. One user-visible change
7035 is that two tabs will list possible command completions, which previously
7036 required typing M-? (meta-question mark, or ESC ?).
7040 The `stepi' bug that many of you noticed has been squashed.
7041 Many bugs in C++ have been handled. Many more remain to be handled.
7042 See the various ChangeLog files (primarily in gdb and bfd) for details.
7044 * State of the MIPS world (in case you wondered):
7046 GDB can understand the symbol tables emitted by the compilers
7047 supplied by most vendors of MIPS-based machines, including DEC. These
7048 symbol tables are in a format that essentially nobody else uses.
7050 Some versions of gcc come with an assembler post-processor called
7051 mips-tfile. This program is required if you want to do source-level
7052 debugging of gcc-compiled programs. I believe FSF does not ship
7053 mips-tfile with gcc version 1, but it will eventually come with gcc
7056 Debugging of g++ output remains a problem. g++ version 1.xx does not
7057 really support it at all. (If you're lucky, you should be able to get
7058 line numbers and stack traces to work, but no parameters or local
7059 variables.) With some work it should be possible to improve the
7062 When gcc version 2 is released, you will have somewhat better luck.
7063 However, even then you will get confusing results for inheritance and
7066 We will eventually provide full debugging of g++ output on
7067 DECstations. This will probably involve some kind of stabs-in-ecoff
7068 encapulation, but the details have not been worked out yet.
7071 *** Changes in GDB-4.2:
7073 * Improved configuration
7075 Only one copy of `configure' exists now, and it is not self-modifying.
7076 Porting BFD is simpler.
7080 The `step' and `next' commands now only stop at the first instruction
7081 of a source line. This prevents the multiple stops that used to occur
7082 in switch statements, for-loops, etc. `Step' continues to stop if a
7083 function that has debugging information is called within the line.
7087 Lots of small bugs fixed. More remain.
7089 * New host supported (not target)
7091 Intel 386 PC clone running Mach i386-none-mach
7094 *** Changes in GDB-4.1:
7096 * Multiple source language support
7098 GDB now has internal scaffolding to handle several source languages.
7099 It determines the type of each source file from its filename extension,
7100 and will switch expression parsing and number formatting to match the
7101 language of the function in the currently selected stack frame.
7102 You can also specifically set the language to be used, with
7103 `set language c' or `set language modula-2'.
7107 GDB now has preliminary support for the GNU Modula-2 compiler,
7108 currently under development at the State University of New York at
7109 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7110 continue through the fall of 1991 and into 1992.
7112 Other Modula-2 compilers are currently not supported, and attempting to
7113 debug programs compiled with them will likely result in an error as the
7114 symbol table is read. Feel free to work on it, though!
7116 There are hooks in GDB for strict type checking and range checking,
7117 in the `Modula-2 philosophy', but they do not currently work.
7121 GDB can now write to executable and core files (e.g. patch
7122 a variable's value). You must turn this switch on, specify
7123 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7124 by assigning a new value to a variable. Modifications take
7127 * Automatic SunOS shared library reading
7129 When you run your program, GDB automatically determines where its
7130 shared libraries (if any) have been loaded, and reads their symbols.
7131 The `share' command is no longer needed. This also works when
7132 examining core files.
7136 You can specify the number of lines that the `list' command shows.
7139 * New machines supported (host and target)
7141 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7142 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7143 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7145 * New hosts supported (not targets)
7147 IBM RT/PC: romp-ibm-aix or rtpc
7149 * New targets supported (not hosts)
7151 AMD 29000 embedded with COFF a29k-none-coff
7152 AMD 29000 embedded with a.out a29k-none-aout
7153 Ultracomputer remote kernel debug a29k-nyu-kern
7155 * New remote interfaces
7161 *** Changes in GDB-4.0:
7165 Wide output is wrapped at good places to make the output more readable.
7167 Gdb now supports cross-debugging from a host machine of one type to a
7168 target machine of another type. Communication with the target system
7169 is over serial lines. The ``target'' command handles connecting to the
7170 remote system; the ``load'' command will download a program into the
7171 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7172 also supports debugging of realtime processes running under VxWorks,
7173 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7174 stub on the target system.
7176 New CPUs supported include the AMD 29000 and Intel 960.
7178 GDB now reads object files and symbol tables via a ``binary file''
7179 library, which allows a single copy of GDB to debug programs of multiple
7180 object file types such as a.out and coff.
7182 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7183 refcard.dvi and refcard.ps are available to format it).
7186 * Control-Variable user interface simplified
7188 All variables that control the operation of the debugger can be set
7189 by the ``set'' command, and displayed by the ``show'' command.
7191 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7192 ``Show prompt'' produces the response:
7193 Gdb's prompt is new-gdb=>.
7195 What follows are the NEW set commands. The command ``help set'' will
7196 print a complete list of old and new set commands. ``help set FOO''
7197 will give a longer description of the variable FOO. ``show'' will show
7198 all of the variable descriptions and their current settings.
7200 confirm on/off: Enables warning questions for operations that are
7201 hard to recover from, e.g. rerunning the program while
7202 it is already running. Default is ON.
7204 editing on/off: Enables EMACS style command line editing
7205 of input. Previous lines can be recalled with
7206 control-P, the current line can be edited with control-B,
7207 you can search for commands with control-R, etc.
7210 history filename NAME: NAME is where the gdb command history
7211 will be stored. The default is .gdb_history,
7212 or the value of the environment variable
7215 history size N: The size, in commands, of the command history. The
7216 default is 256, or the value of the environment variable
7219 history save on/off: If this value is set to ON, the history file will
7220 be saved after exiting gdb. If set to OFF, the
7221 file will not be saved. The default is OFF.
7223 history expansion on/off: If this value is set to ON, then csh-like
7224 history expansion will be performed on
7225 command line input. The default is OFF.
7227 radix N: Sets the default radix for input and output. It can be set
7228 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7229 in the current radix, so "set radix 10" is always a no-op.
7231 height N: This integer value is the number of lines on a page. Default
7232 is 24, the current `stty rows'' setting, or the ``li#''
7233 setting from the termcap entry matching the environment
7236 width N: This integer value is the number of characters on a line.
7237 Default is 80, the current `stty cols'' setting, or the ``co#''
7238 setting from the termcap entry matching the environment
7241 Note: ``set screensize'' is obsolete. Use ``set height'' and
7242 ``set width'' instead.
7244 print address on/off: Print memory addresses in various command displays,
7245 such as stack traces and structure values. Gdb looks
7246 more ``symbolic'' if you turn this off; it looks more
7247 ``machine level'' with it on. Default is ON.
7249 print array on/off: Prettyprint arrays. New convenient format! Default
7252 print demangle on/off: Print C++ symbols in "source" form if on,
7255 print asm-demangle on/off: Same, for assembler level printouts
7258 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7261 * Support for Epoch Environment.
7263 The epoch environment is a version of Emacs v18 with windowing. One
7264 new command, ``inspect'', is identical to ``print'', except that if you
7265 are running in the epoch environment, the value is printed in its own
7269 * Support for Shared Libraries
7271 GDB can now debug programs and core files that use SunOS shared libraries.
7272 Symbols from a shared library cannot be referenced
7273 before the shared library has been linked with the program (this
7274 happens after you type ``run'' and before the function main() is entered).
7275 At any time after this linking (including when examining core files
7276 from dynamically linked programs), gdb reads the symbols from each
7277 shared library when you type the ``sharedlibrary'' command.
7278 It can be abbreviated ``share''.
7280 sharedlibrary REGEXP: Load shared object library symbols for files
7281 matching a unix regular expression. No argument
7282 indicates to load symbols for all shared libraries.
7284 info sharedlibrary: Status of loaded shared libraries.
7289 A watchpoint stops execution of a program whenever the value of an
7290 expression changes. Checking for this slows down execution
7291 tremendously whenever you are in the scope of the expression, but is
7292 quite useful for catching tough ``bit-spreader'' or pointer misuse
7293 problems. Some machines such as the 386 have hardware for doing this
7294 more quickly, and future versions of gdb will use this hardware.
7296 watch EXP: Set a watchpoint (breakpoint) for an expression.
7298 info watchpoints: Information about your watchpoints.
7300 delete N: Deletes watchpoint number N (same as breakpoints).
7301 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7302 enable N: Re-enables watchpoint number N (same as breakpoints).
7305 * C++ multiple inheritance
7307 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7310 * C++ exception handling
7312 Gdb now supports limited C++ exception handling. Besides the existing
7313 ability to breakpoint on an exception handler, gdb can breakpoint on
7314 the raising of an exception (before the stack is peeled back to the
7317 catch FOO: If there is a FOO exception handler in the dynamic scope,
7318 set a breakpoint to catch exceptions which may be raised there.
7319 Multiple exceptions (``catch foo bar baz'') may be caught.
7321 info catch: Lists all exceptions which may be caught in the
7322 current stack frame.
7325 * Minor command changes
7327 The command ``call func (arg, arg, ...)'' now acts like the print
7328 command, except it does not print or save a value if the function's result
7329 is void. This is similar to dbx usage.
7331 The ``up'' and ``down'' commands now always print the frame they end up
7332 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7333 frames without printing.
7335 * New directory command
7337 'dir' now adds directories to the FRONT of the source search path.
7338 The path starts off empty. Source files that contain debug information
7339 about the directory in which they were compiled can be found even
7340 with an empty path; Sun CC and GCC include this information. If GDB can't
7341 find your source file in the current directory, type "dir .".
7343 * Configuring GDB for compilation
7345 For normal use, type ``./configure host''. See README or gdb.texinfo
7348 GDB now handles cross debugging. If you are remotely debugging between
7349 two different machines, type ``./configure host -target=targ''.
7350 Host is the machine where GDB will run; targ is the machine
7351 where the program that you are debugging will run.