1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support access to additional registers on
7 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
10 * GDB now has experimental support for the compilation and injection of
11 C++ source code into the inferior. This beta release does not include
12 support for several language features, such as templates, constructors,
15 This feature requires GCC 7.1 or higher built with libcp1.so
18 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
19 can be passed using the '[ADDRESS]:PORT' notation, or the regular
20 'ADDRESS:PORT' method.
22 * GDB and GDBserver now support local domain socket connections. The
23 name of a local domain socket may be provided instead of the
24 [ADDRESS]:PORT notation.
26 * DWARF index cache: GDB can now automatically save indices of DWARF
27 symbols on disk to speed up further loading of the same binaries.
29 * GDB in batch mode now exits with status 1 if the last command to be
32 * Changes to the "frame", "select-frame", and "info frame" CLI
33 commands. These commands all now take a frame specification which
34 is either a frame level, or one of the keywords 'level', 'address',
35 'function', or 'view' followed by a parameter. Selecting a frame by
36 address, or viewing a frame outside the current backtrace now
37 requires the use of a keyword. Selecting a frame by level is
38 unchanged. The MI comment "-stack-select-frame" is unchanged.
46 set debug compile-cplus-types
47 show debug compile-cplus-types
48 Control the display of debug output about type conversion in the
49 C++ compile feature. Commands have no effect while compiliong
54 Control whether debug output about files/functions skipping is
57 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
58 Apply a command to some frames.
59 FLAG arguments allow to control what output to produce and how to handle
60 errors raised when applying COMMAND to a frame.
63 Apply a command to all threads (ignoring errors and empty output).
64 Shortcut for 'thread apply all -s COMMAND'.
67 Apply a command to all frames (ignoring errors and empty output).
68 Shortcut for 'frame apply all -s COMMAND'.
71 Apply a command to all frames of all threads (ignoring errors and empty
73 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
75 maint set dwarf unwinders (on|off)
76 maint show dwarf unwinders
77 Control whether DWARF unwinders can be used.
80 Display a list of open files for a process.
84 target remote FILENAME
85 target extended-remote FILENAME
86 If FILENAME is a Unix domain socket, GDB will attempt to connect
87 to this socket instead of opening FILENAME as a character device.
89 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
90 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
91 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
92 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
93 These commands can now print only the searched entities
94 matching the provided regexp(s), giving a condition
95 on the entity names or entity types. The flag -q disables
96 printing headers or informations messages.
98 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
99 The 'thread apply' command accepts new FLAG arguments.
100 FLAG arguments allow to control what output to produce and how to handle
101 errors raised when applying COMMAND to a thread.
103 set tui tab-width NCHARS
104 show tui tab-width NCHARS
105 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
109 ** The '-data-disassemble' MI command now accepts an '-a' option to
110 disassemble the whole function surrounding the given program
111 counter value or function name. Support for this feature can be
112 verified by using the "-list-features" command, which should
113 contain "data-disassemble-a-option".
115 ** Command responses and notifications that include a frame now include
116 the frame's architecture in a new "arch" attribute.
118 * New native configurations
120 GNU/Linux/RISC-V riscv*-*-linux*
121 FreeBSD/riscv riscv*-*-freebsd*
125 GNU/Linux/RISC-V riscv*-*-linux*
127 CSKY GNU/LINUX csky*-*-linux
128 FreeBSD/riscv riscv*-*-freebsd*
132 ** The gdb.Inferior type has a new 'progspace' property, which is the program
133 space associated to that inferior.
135 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
136 of objfiles associated to that program space.
138 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
139 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
142 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
143 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
144 correct and did not work properly.
150 Enable or disable the undefined behavior sanitizer. This is
151 disabled by default, but passing --enable-ubsan=yes or
152 --enable-ubsan=auto to configure will enable it. Enabling this can
153 cause a performance penalty. The undefined behavior sanitizer was
154 first introduced in GCC 4.9.
156 *** Changes in GDB 8.2
158 * The 'set disassembler-options' command now supports specifying options
161 * The 'symbol-file' command now accepts an '-o' option to add a relative
162 offset to all sections.
164 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
165 a relative offset to all sections, but it allows to override the load
166 address of individual sections using '-s'.
168 * The 'add-symbol-file' command no longer requires the second argument
169 (address of the text section).
171 * The endianness used with the 'set endian auto' mode in the absence of
172 an executable selected for debugging is now the last endianness chosen
173 either by one of the 'set endian big' and 'set endian little' commands
174 or by inferring from the last executable used, rather than the startup
177 * The pager now allows a "c" response, meaning to disable the pager
178 for the rest of the current command.
180 * The commands 'info variables/functions/types' now show the source line
181 numbers of symbol definitions when available.
183 * 'info proc' now works on running processes on FreeBSD systems and core
184 files created on FreeBSD systems.
186 * C expressions can now use _Alignof, and C++ expressions can now use
189 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
190 the vector length while the process is running.
196 Control display of debugging info regarding the FreeBSD native target.
198 set|show varsize-limit
199 This new setting allows the user to control the maximum size of Ada
200 objects being printed when those objects have a variable type,
201 instead of that maximum size being hardcoded to 65536 bytes.
203 set|show record btrace cpu
204 Controls the processor to be used for enabling errata workarounds for
207 maint check libthread-db
208 Run integrity checks on the current inferior's thread debugging
211 maint set check-libthread-db (on|off)
212 maint show check-libthread-db
213 Control whether to run integrity checks on inferior specific thread
214 debugging libraries as they are loaded. The default is not to
219 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
221 ** The commands attached to a breakpoint can be set by assigning to
222 the breakpoint's "commands" field.
224 ** gdb.execute can now execute multi-line gdb commands.
226 ** The new functions gdb.convenience_variable and
227 gdb.set_convenience_variable can be used to get and set the value
228 of convenience variables.
230 ** A gdb.Parameter will no longer print the "set" help text on an
231 ordinary "set"; instead by default a "set" will be silent unless
232 the get_set_string method returns a non-empty string.
236 RiscV ELF riscv*-*-elf
238 * Removed targets and native configurations
240 m88k running OpenBSD m88*-*-openbsd*
241 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
242 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
243 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
245 * Aarch64/Linux hardware watchpoints improvements
247 Hardware watchpoints on unaligned addresses are now properly
248 supported when running Linux kernel 4.10 or higher: read and access
249 watchpoints are no longer spuriously missed, and all watchpoints
250 lengths between 1 and 8 bytes are supported. On older kernels,
251 watchpoints set on unaligned addresses are no longer missed, with
252 the tradeoff that there is a possibility of false hits being
257 --enable-codesign=CERT
258 This can be used to invoke "codesign -s CERT" after building gdb.
259 This option is useful on macOS, where code signing is required for
260 gdb to work properly.
262 --disable-gdbcli has been removed
263 This is now silently accepted, but does nothing.
265 *** Changes in GDB 8.1
267 * GDB now supports dynamically creating arbitrary register groups specified
268 in XML target descriptions. This allows for finer grain grouping of
269 registers on systems with a large amount of registers.
271 * The 'ptype' command now accepts a '/o' flag, which prints the
272 offsets and sizes of fields in a struct, like the pahole(1) tool.
274 * New "--readnever" command line option instructs GDB to not read each
275 symbol file's symbolic debug information. This makes startup faster
276 but at the expense of not being able to perform symbolic debugging.
277 This option is intended for use cases where symbolic debugging will
278 not be used, e.g., when you only need to dump the debuggee's core.
280 * GDB now uses the GNU MPFR library, if available, to emulate target
281 floating-point arithmetic during expression evaluation when the target
282 uses different floating-point formats than the host. At least version
283 3.1 of GNU MPFR is required.
285 * GDB now supports access to the guarded-storage-control registers and the
286 software-based guarded-storage broadcast control registers on IBM z14.
288 * On Unix systems, GDB now supports transmitting environment variables
289 that are to be set or unset to GDBserver. These variables will
290 affect the environment to be passed to the remote inferior.
292 To inform GDB of environment variables that are to be transmitted to
293 GDBserver, use the "set environment" command. Only user set
294 environment variables are sent to GDBserver.
296 To inform GDB of environment variables that are to be unset before
297 the remote inferior is started by the GDBserver, use the "unset
298 environment" command.
300 * Completion improvements
302 ** GDB can now complete function parameters in linespecs and
303 explicit locations without quoting. When setting breakpoints,
304 quoting around functions names to help with TAB-completion is
305 generally no longer necessary. For example, this now completes
308 (gdb) b function(in[TAB]
309 (gdb) b function(int)
311 Related, GDB is no longer confused with completing functions in
312 C++ anonymous namespaces:
315 (gdb) b (anonymous namespace)::[TAB][TAB]
316 (anonymous namespace)::a_function()
317 (anonymous namespace)::b_function()
319 ** GDB now has much improved linespec and explicit locations TAB
320 completion support, that better understands what you're
321 completing and offers better suggestions. For example, GDB no
322 longer offers data symbols as possible completions when you're
323 setting a breakpoint.
325 ** GDB now TAB-completes label symbol names.
327 ** The "complete" command now mimics TAB completion accurately.
329 * New command line options (gcore)
332 Dump all memory mappings.
334 * Breakpoints on C++ functions are now set on all scopes by default
336 By default, breakpoints on functions/methods are now interpreted as
337 specifying all functions with the given name ignoring missing
338 leading scopes (namespaces and classes).
340 For example, assuming a C++ program with symbols named:
345 both commands "break func()" and "break B::func()" set a breakpoint
348 You can use the new flag "-qualified" to override this. This makes
349 GDB interpret the specified function name as a complete
350 fully-qualified name instead. For example, using the same C++
351 program, the "break -q B::func" command sets a breakpoint on
352 "B::func", only. A parameter has been added to the Python
353 gdb.Breakpoint constructor to achieve the same result when creating
354 a breakpoint from Python.
356 * Breakpoints on functions marked with C++ ABI tags
358 GDB can now set breakpoints on functions marked with C++ ABI tags
359 (e.g., [abi:cxx11]). See here for a description of ABI tags:
360 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
362 Functions with a C++11 abi tag are demangled/displayed like this:
364 function[abi:cxx11](int)
367 You can now set a breakpoint on such functions simply as if they had
370 (gdb) b function(int)
372 Or if you need to disambiguate between tags, like:
374 (gdb) b function[abi:other_tag](int)
376 Tab completion was adjusted accordingly as well.
380 ** New events gdb.new_inferior, gdb.inferior_deleted, and
381 gdb.new_thread are emitted. See the manual for further
382 description of these.
384 ** A new function, "gdb.rbreak" has been added to the Python API.
385 This function allows the setting of a large number of breakpoints
386 via a regex pattern in Python. See the manual for further details.
388 ** Python breakpoints can now accept explicit locations. See the
389 manual for a further description of this feature.
392 * New features in the GDB remote stub, GDBserver
394 ** GDBserver is now able to start inferior processes with a
395 specified initial working directory.
397 The user can set the desired working directory to be used from
398 GDB using the new "set cwd" command.
400 ** New "--selftest" command line option runs some GDBserver self
401 tests. These self tests are disabled in releases.
403 ** On Unix systems, GDBserver now does globbing expansion and variable
404 substitution in inferior command line arguments.
406 This is done by starting inferiors using a shell, like GDB does.
407 See "set startup-with-shell" in the user manual for how to disable
408 this from GDB when using "target extended-remote". When using
409 "target remote", you can disable the startup with shell by using the
410 new "--no-startup-with-shell" GDBserver command line option.
412 ** On Unix systems, GDBserver now supports receiving environment
413 variables that are to be set or unset from GDB. These variables
414 will affect the environment to be passed to the inferior.
416 * When catching an Ada exception raised with a message, GDB now prints
417 the message in the catchpoint hit notification. In GDB/MI mode, that
418 information is provided as an extra field named "exception-message"
419 in the *stopped notification.
421 * Trait objects can now be inspected When debugging Rust code. This
422 requires compiler support which will appear in Rust 1.24.
426 QEnvironmentHexEncoded
427 Inform GDBserver of an environment variable that is to be passed to
428 the inferior when starting it.
431 Inform GDBserver of an environment variable that is to be unset
432 before starting the remote inferior.
435 Inform GDBserver that the environment should be reset (i.e.,
436 user-set environment variables should be unset).
439 Indicates whether the inferior must be started with a shell or not.
442 Tell GDBserver that the inferior to be started should use a specific
445 * The "maintenance print c-tdesc" command now takes an optional
446 argument which is the file name of XML target description.
448 * The "maintenance selftest" command now takes an optional argument to
449 filter the tests to be run.
451 * The "enable", and "disable" commands now accept a range of
452 breakpoint locations, e.g. "enable 1.3-5".
457 Set and show the current working directory for the inferior.
460 Set and show compilation command used for compiling and injecting code
461 with the 'compile' commands.
463 set debug separate-debug-file
464 show debug separate-debug-file
465 Control the display of debug output about separate debug file search.
467 set dump-excluded-mappings
468 show dump-excluded-mappings
469 Control whether mappings marked with the VM_DONTDUMP flag should be
470 dumped when generating a core file.
473 List the registered selftests.
476 Start the debugged program stopping at the first instruction.
479 Control display of debugging messages related to OpenRISC targets.
481 set|show print type nested-type-limit
482 Set and show the limit of nesting level for nested types that the
483 type printer will show.
485 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
488 * Safer/improved support for debugging with no debug info
490 GDB no longer assumes functions with no debug information return
493 This means that GDB now refuses to call such functions unless you
494 tell it the function's type, by either casting the call to the
495 declared return type, or by casting the function to a function
496 pointer of the right type, and calling that:
498 (gdb) p getenv ("PATH")
499 'getenv' has unknown return type; cast the call to its declared return type
500 (gdb) p (char *) getenv ("PATH")
501 $1 = 0x7fffffffe "/usr/local/bin:/"...
502 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
503 $2 = 0x7fffffffe "/usr/local/bin:/"...
505 Similarly, GDB no longer assumes that global variables with no debug
506 info have type 'int', and refuses to print the variable's value
507 unless you tell it the variable's type:
510 'var' has unknown type; cast it to its declared type
514 * New native configurations
516 FreeBSD/aarch64 aarch64*-*-freebsd*
517 FreeBSD/arm arm*-*-freebsd*
521 FreeBSD/aarch64 aarch64*-*-freebsd*
522 FreeBSD/arm arm*-*-freebsd*
523 OpenRISC ELF or1k*-*-elf
525 * Removed targets and native configurations
527 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
529 *** Changes in GDB 8.0
531 * GDB now supports access to the PKU register on GNU/Linux. The register is
532 added by the Memory Protection Keys for Userspace feature which will be
533 available in future Intel CPUs.
535 * GDB now supports C++11 rvalue references.
539 ** New functions to start, stop and access a running btrace recording.
540 ** Rvalue references are now supported in gdb.Type.
542 * GDB now supports recording and replaying rdrand and rdseed Intel 64
545 * Building GDB and GDBserver now requires a C++11 compiler.
547 For example, GCC 4.8 or later.
549 It is no longer possible to build GDB or GDBserver with a C
550 compiler. The --disable-build-with-cxx configure option has been
553 * Building GDB and GDBserver now requires GNU make >= 3.81.
555 It is no longer supported to build GDB or GDBserver with another
556 implementation of the make program or an earlier version of GNU make.
558 * Native debugging on MS-Windows supports command-line redirection
560 Command-line arguments used for starting programs on MS-Windows can
561 now include redirection symbols supported by native Windows shells,
562 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
563 as "run", "start", and "set args", as well as the corresponding MI
566 * Support for thread names on MS-Windows.
568 GDB now catches and handles the special exception that programs
569 running on MS-Windows use to assign names to threads in the
572 * Support for Java programs compiled with gcj has been removed.
574 * User commands now accept an unlimited number of arguments.
575 Previously, only up to 10 was accepted.
577 * The "eval" command now expands user-defined command arguments.
579 This makes it easier to process a variable number of arguments:
584 eval "print $arg%d", $i
589 * Target descriptions can now describe registers for sparc32 and sparc64.
591 * GDB now supports DWARF version 5 (debug information format).
592 Its .debug_names index is not yet supported.
594 * New native configurations
596 FreeBSD/mips mips*-*-freebsd
600 Synopsys ARC arc*-*-elf32
601 FreeBSD/mips mips*-*-freebsd
603 * Removed targets and native configurations
605 Alpha running FreeBSD alpha*-*-freebsd*
606 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
611 Erases all the flash memory regions reported by the target.
613 maint print arc arc-instruction address
614 Print internal disassembler information about instruction at a given address.
618 set disassembler-options
619 show disassembler-options
620 Controls the passing of target specific information to the disassembler.
621 If it is necessary to specify more than one disassembler option then
622 multiple options can be placed together into a comma separated list.
623 The default value is the empty string. Currently, the only supported
624 targets are ARM, PowerPC and S/390.
629 Erases all the flash memory regions reported by the target. This is
630 equivalent to the CLI command flash-erase.
632 -file-list-shared-libraries
633 List the shared libraries in the program. This is
634 equivalent to the CLI command "info shared".
637 Catchpoints stopping the program when Ada exceptions are
638 handled. This is equivalent to the CLI command "catch handlers".
640 *** Changes in GDB 7.12
642 * GDB and GDBserver now build with a C++ compiler by default.
644 The --enable-build-with-cxx configure option is now enabled by
645 default. One must now explicitly configure with
646 --disable-build-with-cxx in order to build with a C compiler. This
647 option will be removed in a future release.
649 * GDBserver now supports recording btrace without maintaining an active
652 * GDB now supports a negative repeat count in the 'x' command to examine
653 memory backward from the given address. For example:
656 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
657 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
658 (gdb) x/-5i 0x0000000000400580
659 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
660 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
661 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
662 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
663 0x40057b <main(int, char**)+25>:
664 callq 0x400536 <Func1(int, char const*)>
666 * Fortran: Support structures with fields of dynamic types and
667 arrays of dynamic types.
669 * The symbol dumping maintenance commands have new syntax.
670 maint print symbols [-pc address] [--] [filename]
671 maint print symbols [-objfile objfile] [-source source] [--] [filename]
672 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
673 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
674 maint print msymbols [-objfile objfile] [--] [filename]
676 * GDB now supports multibit bitfields and enums in target register
679 * New Python-based convenience function $_as_string(val), which returns
680 the textual representation of a value. This function is especially
681 useful to obtain the text label of an enum value.
683 * Intel MPX bound violation handling.
685 Segmentation faults caused by a Intel MPX boundary violation
686 now display the kind of violation (upper or lower), the memory
687 address accessed and the memory bounds, along with the usual
688 signal received and code location.
692 Program received signal SIGSEGV, Segmentation fault
693 Upper bound violation while accessing address 0x7fffffffc3b3
694 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
695 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
697 * Rust language support.
698 GDB now supports debugging programs written in the Rust programming
699 language. See https://www.rust-lang.org/ for more information about
702 * Support for running interpreters on specified input/output devices
704 GDB now supports a new mechanism that allows frontends to provide
705 fully featured GDB console views, as a better alternative to
706 building such views on top of the "-interpreter-exec console"
707 command. See the new "new-ui" command below. With that command,
708 frontends can now start GDB in the traditional command-line mode
709 running in an embedded terminal emulator widget, and create a
710 separate MI interpreter running on a specified i/o device. In this
711 way, GDB handles line editing, history, tab completion, etc. in the
712 console all by itself, and the GUI uses the separate MI interpreter
713 for its own control and synchronization, invisible to the command
716 * The "catch syscall" command catches groups of related syscalls.
718 The "catch syscall" command now supports catching a group of related
719 syscalls using the 'group:' or 'g:' prefix.
724 skip -gfile file-glob-pattern
725 skip -function function
726 skip -rfunction regular-expression
727 A generalized form of the skip command, with new support for
728 glob-style file names and regular expressions for function names.
729 Additionally, a file spec and a function spec may now be combined.
731 maint info line-table REGEXP
732 Display the contents of GDB's internal line table data struture.
735 Run any GDB unit tests that were compiled in.
738 Start a new user interface instance running INTERP as interpreter,
739 using the TTY file for input/output.
743 ** gdb.Breakpoint objects have a new attribute "pending", which
744 indicates whether the breakpoint is pending.
745 ** Three new breakpoint-related events have been added:
746 gdb.breakpoint_created, gdb.breakpoint_modified, and
747 gdb.breakpoint_deleted.
750 Signal ("set") the given MS-Windows event object. This is used in
751 conjunction with the Windows JIT debugging (AeDebug) support, where
752 the OS suspends a crashing process until a debugger can attach to
753 it. Resuming the crashing process, in order to debug it, is done by
756 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
757 was added in GDBserver, including JIT compiling fast tracepoint's
758 conditional expression bytecode into native code.
760 * Support for various remote target protocols and ROM monitors has
763 target m32rsdi Remote M32R debugging over SDI
764 target mips MIPS remote debugging protocol
765 target pmon PMON ROM monitor
766 target ddb NEC's DDB variant of PMON for Vr4300
767 target rockhopper NEC RockHopper variant of PMON
768 target lsi LSI variant of PMO
770 * Support for tracepoints and fast tracepoints on powerpc-linux,
771 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
772 including JIT compiling fast tracepoint's conditional expression
773 bytecode into native code.
775 * MI async record =record-started now includes the method and format used for
776 recording. For example:
778 =record-started,thread-group="i1",method="btrace",format="bts"
780 * MI async record =thread-selected now includes the frame field. For example:
782 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
786 Andes NDS32 nds32*-*-elf
788 *** Changes in GDB 7.11
790 * GDB now supports debugging kernel-based threads on FreeBSD.
792 * Per-inferior thread numbers
794 Thread numbers are now per inferior instead of global. If you're
795 debugging multiple inferiors, GDB displays thread IDs using a
796 qualified INF_NUM.THR_NUM form. For example:
800 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
801 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
802 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
803 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
805 As consequence, thread numbers as visible in the $_thread
806 convenience variable and in Python's InferiorThread.num attribute
807 are no longer unique between inferiors.
809 GDB now maintains a second thread ID per thread, referred to as the
810 global thread ID, which is the new equivalent of thread numbers in
811 previous releases. See also $_gthread below.
813 For backwards compatibility, MI's thread IDs always refer to global
816 * Commands that accept thread IDs now accept the qualified
817 INF_NUM.THR_NUM form as well. For example:
820 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
823 * In commands that accept a list of thread IDs, you can now refer to
824 all threads of an inferior using a star wildcard. GDB accepts
825 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
826 refer to all threads of the current inferior. For example, "info
829 * You can use "info threads -gid" to display the global thread ID of
832 * The new convenience variable $_gthread holds the global number of
835 * The new convenience variable $_inferior holds the number of the
838 * GDB now displays the ID and name of the thread that hit a breakpoint
839 or received a signal, if your program is multi-threaded. For
842 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
843 Thread 1 "main" received signal SIGINT, Interrupt.
845 * Record btrace now supports non-stop mode.
847 * Support for tracepoints on aarch64-linux was added in GDBserver.
849 * The 'record instruction-history' command now indicates speculative execution
850 when using the Intel Processor Trace recording format.
852 * GDB now allows users to specify explicit locations, bypassing
853 the linespec parser. This feature is also available to GDB/MI
856 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
857 GDB now is able to debug both AArch64 applications and ARM applications
860 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
861 including JIT compiling fast tracepoint's conditional expression bytecode
864 * GDB now supports displaced stepping on AArch64 GNU/Linux.
866 * "info threads", "info inferiors", "info display", "info checkpoints"
867 and "maint info program-spaces" now list the corresponding items in
868 ascending ID order, for consistency with all other "info" commands.
870 * In Ada, the overloads selection menu has been enhanced to display the
871 parameter types and the return types for the matching overloaded subprograms.
875 maint set target-non-stop (on|off|auto)
876 maint show target-non-stop
877 Control whether GDB targets always operate in non-stop mode even if
878 "set non-stop" is "off". The default is "auto", meaning non-stop
879 mode is enabled if supported by the target.
881 maint set bfd-sharing
882 maint show bfd-sharing
883 Control the reuse of bfd objects.
887 Control display of debugging info regarding bfd caching.
891 Control display of debugging info regarding FreeBSD threads.
893 set remote multiprocess-extensions-packet
894 show remote multiprocess-extensions-packet
895 Set/show the use of the remote protocol multiprocess extensions.
897 set remote thread-events
898 show remote thread-events
899 Set/show the use of thread create/exit events.
901 set ada print-signatures on|off
902 show ada print-signatures"
903 Control whether parameter types and return types are displayed in overloads
904 selection menus. It is activaled (@code{on}) by default.
908 Controls the maximum size of memory, in bytes, that GDB will
909 allocate for value contents. Prevents incorrect programs from
910 causing GDB to allocate overly large buffers. Default is 64k.
912 * The "disassemble" command accepts a new modifier: /s.
913 It prints mixed source+disassembly like /m with two differences:
914 - disassembled instructions are now printed in program order, and
915 - and source for all relevant files is now printed.
916 The "/m" option is now considered deprecated: its "source-centric"
917 output hasn't proved useful in practice.
919 * The "record instruction-history" command accepts a new modifier: /s.
920 It behaves exactly like /m and prints mixed source+disassembly.
922 * The "set scheduler-locking" command supports a new mode "replay".
923 It behaves like "off" in record mode and like "on" in replay mode.
925 * Support for various ROM monitors has been removed:
927 target dbug dBUG ROM monitor for Motorola ColdFire
928 target picobug Motorola picobug monitor
929 target dink32 DINK32 ROM monitor for PowerPC
930 target m32r Renesas M32R/D ROM monitor
931 target mon2000 mon2000 ROM monitor
932 target ppcbug PPCBUG ROM monitor for PowerPC
934 * Support for reading/writing memory and extracting values on architectures
935 whose memory is addressable in units of any integral multiple of 8 bits.
938 Allows to break when an Ada exception is handled.
943 Indicates that an exec system call was executed.
945 exec-events feature in qSupported
946 The qSupported packet allows GDB to request support for exec
947 events using the new 'gdbfeature' exec-event, and the qSupported
948 response can contain the corresponding 'stubfeature'. Set and
949 show commands can be used to display whether these features are enabled.
952 Equivalent to interrupting with the ^C character, but works in
955 thread created stop reason (T05 create:...)
956 Indicates that the thread was just created and is stopped at entry.
958 thread exit stop reply (w exitcode;tid)
959 Indicates that the thread has terminated.
962 Enables/disables thread create and exit event reporting. For
963 example, this is used in non-stop mode when GDB stops a set of
964 threads and synchronously waits for the their corresponding stop
965 replies. Without exit events, if one of the threads exits, GDB
966 would hang forever not knowing that it should no longer expect a
967 stop for that same thread.
970 Indicates that there are no resumed threads left in the target (all
971 threads are stopped). The remote stub reports support for this stop
972 reply to GDB's qSupported query.
975 Enables/disables catching syscalls from the inferior process.
976 The remote stub reports support for this packet to GDB's qSupported query.
978 syscall_entry stop reason
979 Indicates that a syscall was just called.
981 syscall_return stop reason
982 Indicates that a syscall just returned.
984 * Extended-remote exec events
986 ** GDB now has support for exec events on extended-remote Linux targets.
987 For such targets with Linux kernels 2.5.46 and later, this enables
988 follow-exec-mode and exec catchpoints.
990 set remote exec-event-feature-packet
991 show remote exec-event-feature-packet
992 Set/show the use of the remote exec event feature.
994 * Thread names in remote protocol
996 The reply to qXfer:threads:read may now include a name attribute for each
999 * Target remote mode fork and exec events
1001 ** GDB now has support for fork and exec events on target remote mode
1002 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1003 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1004 fork and exec catchpoints.
1006 * Remote syscall events
1008 ** GDB now has support for catch syscall on remote Linux targets,
1009 currently enabled on x86/x86_64 architectures.
1011 set remote catch-syscall-packet
1012 show remote catch-syscall-packet
1013 Set/show the use of the remote catch syscall feature.
1017 ** The -var-set-format command now accepts the zero-hexadecimal
1018 format. It outputs data in hexadecimal format with zero-padding on the
1023 ** gdb.InferiorThread objects have a new attribute "global_num",
1024 which refers to the thread's global thread ID. The existing
1025 "num" attribute now refers to the thread's per-inferior number.
1026 See "Per-inferior thread numbers" above.
1027 ** gdb.InferiorThread objects have a new attribute "inferior", which
1028 is the Inferior object the thread belongs to.
1030 *** Changes in GDB 7.10
1032 * Support for process record-replay and reverse debugging on aarch64*-linux*
1033 targets has been added. GDB now supports recording of A64 instruction set
1034 including advance SIMD instructions.
1036 * Support for Sun's version of the "stabs" debug file format has been removed.
1038 * GDB now honors the content of the file /proc/PID/coredump_filter
1039 (PID is the process ID) on GNU/Linux systems. This file can be used
1040 to specify the types of memory mappings that will be included in a
1041 corefile. For more information, please refer to the manual page of
1042 "core(5)". GDB also has a new command: "set use-coredump-filter
1043 on|off". It allows to set whether GDB will read the content of the
1044 /proc/PID/coredump_filter file when generating a corefile.
1046 * The "info os" command on GNU/Linux can now display information on
1048 "info os cpus" Listing of all cpus/cores on the system
1050 * GDB has two new commands: "set serial parity odd|even|none" and
1051 "show serial parity". These allows to set or show parity for the
1054 * The "info source" command now displays the producer string if it was
1055 present in the debug info. This typically includes the compiler version
1056 and may include things like its command line arguments.
1058 * The "info dll", an alias of the "info sharedlibrary" command,
1059 is now available on all platforms.
1061 * Directory names supplied to the "set sysroot" commands may be
1062 prefixed with "target:" to tell GDB to access shared libraries from
1063 the target system, be it local or remote. This replaces the prefix
1064 "remote:". The default sysroot has been changed from "" to
1065 "target:". "remote:" is automatically converted to "target:" for
1066 backward compatibility.
1068 * The system root specified by "set sysroot" will be prepended to the
1069 filename of the main executable (if reported to GDB as absolute by
1070 the operating system) when starting processes remotely, and when
1071 attaching to already-running local or remote processes.
1073 * GDB now supports automatic location and retrieval of executable
1074 files from remote targets. Remote debugging can now be initiated
1075 using only a "target remote" or "target extended-remote" command
1076 (no "set sysroot" or "file" commands are required). See "New remote
1079 * The "dump" command now supports verilog hex format.
1081 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1083 * On GNU/Linux, GDB and gdbserver are now able to access executable
1084 and shared library files without a "set sysroot" command when
1085 attaching to processes running in different mount namespaces from
1086 the debugger. This makes it possible to attach to processes in
1087 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1088 See "New remote packets" below.
1090 * The "tui reg" command now provides completion for all of the
1091 available register groups, including target specific groups.
1093 * The HISTSIZE environment variable is no longer read when determining
1094 the size of GDB's command history. GDB now instead reads the dedicated
1095 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1096 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1101 ** Memory ports can now be unbuffered.
1105 ** gdb.Objfile objects have a new attribute "username",
1106 which is the name of the objfile as specified by the user,
1107 without, for example, resolving symlinks.
1108 ** You can now write frame unwinders in Python.
1109 ** gdb.Type objects have a new method "optimized_out",
1110 returning optimized out gdb.Value instance of this type.
1111 ** gdb.Value objects have new methods "reference_value" and
1112 "const_value" which return a reference to the value and a
1113 "const" version of the value respectively.
1117 maint print symbol-cache
1118 Print the contents of the symbol cache.
1120 maint print symbol-cache-statistics
1121 Print statistics of symbol cache usage.
1123 maint flush-symbol-cache
1124 Flush the contents of the symbol cache.
1128 Start branch trace recording using Branch Trace Store (BTS) format.
1131 Evaluate expression by using the compiler and print result.
1135 Explicit commands for enabling and disabling tui mode.
1138 set mpx bound on i386 and amd64
1139 Support for bound table investigation on Intel MPX enabled applications.
1143 Start branch trace recording using Intel Processor Trace format.
1146 Print information about branch tracing internals.
1148 maint btrace packet-history
1149 Print the raw branch tracing data.
1151 maint btrace clear-packet-history
1152 Discard the stored raw branch tracing data.
1155 Discard all branch tracing data. It will be fetched and processed
1156 anew by the next "record" command.
1161 Renamed from "set debug dwarf2-die".
1162 show debug dwarf-die
1163 Renamed from "show debug dwarf2-die".
1165 set debug dwarf-read
1166 Renamed from "set debug dwarf2-read".
1167 show debug dwarf-read
1168 Renamed from "show debug dwarf2-read".
1170 maint set dwarf always-disassemble
1171 Renamed from "maint set dwarf2 always-disassemble".
1172 maint show dwarf always-disassemble
1173 Renamed from "maint show dwarf2 always-disassemble".
1175 maint set dwarf max-cache-age
1176 Renamed from "maint set dwarf2 max-cache-age".
1177 maint show dwarf max-cache-age
1178 Renamed from "maint show dwarf2 max-cache-age".
1180 set debug dwarf-line
1181 show debug dwarf-line
1182 Control display of debugging info regarding DWARF line processing.
1185 show max-completions
1186 Set the maximum number of candidates to be considered during
1187 completion. The default value is 200. This limit allows GDB
1188 to avoid generating large completion lists, the computation of
1189 which can cause the debugger to become temporarily unresponsive.
1191 set history remove-duplicates
1192 show history remove-duplicates
1193 Control the removal of duplicate history entries.
1195 maint set symbol-cache-size
1196 maint show symbol-cache-size
1197 Control the size of the symbol cache.
1199 set|show record btrace bts buffer-size
1200 Set and show the size of the ring buffer used for branch tracing in
1202 The obtained size may differ from the requested size. Use "info
1203 record" to see the obtained buffer size.
1205 set debug linux-namespaces
1206 show debug linux-namespaces
1207 Control display of debugging info regarding Linux namespaces.
1209 set|show record btrace pt buffer-size
1210 Set and show the size of the ring buffer used for branch tracing in
1211 Intel Processor Trace format.
1212 The obtained size may differ from the requested size. Use "info
1213 record" to see the obtained buffer size.
1215 maint set|show btrace pt skip-pad
1216 Set and show whether PAD packets are skipped when computing the
1219 * The command 'thread apply all' can now support new option '-ascending'
1220 to call its specified command for all threads in ascending order.
1222 * Python/Guile scripting
1224 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1225 special section named `.debug_gdb_scripts'.
1227 * New remote packets
1229 qXfer:btrace-conf:read
1230 Return the branch trace configuration for the current thread.
1232 Qbtrace-conf:bts:size
1233 Set the requested ring buffer size for branch tracing in BTS format.
1236 Enable Intel Procesor Trace-based branch tracing for the current
1237 process. The remote stub reports support for this packet to GDB's
1240 Qbtrace-conf:pt:size
1241 Set the requested ring buffer size for branch tracing in Intel Processor
1245 Indicates a memory breakpoint instruction was executed, irrespective
1246 of whether it was GDB that planted the breakpoint or the breakpoint
1247 is hardcoded in the program. This is required for correct non-stop
1251 Indicates the target stopped for a hardware breakpoint. This is
1252 required for correct non-stop mode operation.
1255 Return information about files on the remote system.
1257 qXfer:exec-file:read
1258 Return the full absolute name of the file that was executed to
1259 create a process running on the remote system.
1262 Select the filesystem on which vFile: operations with filename
1263 arguments will operate. This is required for GDB to be able to
1264 access files on remote targets where the remote stub does not
1265 share a common filesystem with the inferior(s).
1268 Indicates that a fork system call was executed.
1271 Indicates that a vfork system call was executed.
1273 vforkdone stop reason
1274 Indicates that a vfork child of the specified process has executed
1275 an exec or exit, allowing the vfork parent to resume execution.
1277 fork-events and vfork-events features in qSupported
1278 The qSupported packet allows GDB to request support for fork and
1279 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1280 and the qSupported response can contain the corresponding
1281 'stubfeatures'. Set and show commands can be used to display
1282 whether these features are enabled.
1284 * Extended-remote fork events
1286 ** GDB now has support for fork events on extended-remote Linux
1287 targets. For targets with Linux kernels 2.5.60 and later, this
1288 enables follow-fork-mode and detach-on-fork for both fork and
1289 vfork, as well as fork and vfork catchpoints.
1291 * The info record command now shows the recording format and the
1292 branch tracing configuration for the current thread when using
1293 the btrace record target.
1294 For the BTS format, it shows the ring buffer size.
1296 * GDB now has support for DTrace USDT (Userland Static Defined
1297 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1299 * GDB now supports access to vector registers on S/390 GNU/Linux
1302 * Removed command line options
1304 -xdb HP-UX XDB compatibility mode.
1306 * Removed targets and native configurations
1308 HP/PA running HP-UX hppa*-*-hpux*
1309 Itanium running HP-UX ia64-*-hpux*
1311 * New configure options
1314 This configure option allows the user to build GDB with support for
1315 Intel Processor Trace (default: auto). This requires libipt.
1317 --with-libipt-prefix=PATH
1318 Specify the path to the version of libipt that GDB should use.
1319 $PATH/include should contain the intel-pt.h header and
1320 $PATH/lib should contain the libipt.so library.
1322 *** Changes in GDB 7.9.1
1326 ** Xmethods can now specify a result type.
1328 *** Changes in GDB 7.9
1330 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1334 ** You can now access frame registers from Python scripts.
1335 ** New attribute 'producer' for gdb.Symtab objects.
1336 ** gdb.Objfile objects have a new attribute "progspace",
1337 which is the gdb.Progspace object of the containing program space.
1338 ** gdb.Objfile objects have a new attribute "owner".
1339 ** gdb.Objfile objects have a new attribute "build_id",
1340 which is the build ID generated when the file was built.
1341 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1342 ** A new event "gdb.clear_objfiles" has been added, triggered when
1343 selecting a new file to debug.
1344 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1345 ** New function gdb.lookup_objfile.
1347 New events which are triggered when GDB modifies the state of the
1350 ** gdb.events.inferior_call_pre: Function call is about to be made.
1351 ** gdb.events.inferior_call_post: Function call has just been made.
1352 ** gdb.events.memory_changed: A memory location has been altered.
1353 ** gdb.events.register_changed: A register has been altered.
1355 * New Python-based convenience functions:
1357 ** $_caller_is(name [, number_of_frames])
1358 ** $_caller_matches(regexp [, number_of_frames])
1359 ** $_any_caller_is(name [, number_of_frames])
1360 ** $_any_caller_matches(regexp [, number_of_frames])
1362 * GDB now supports the compilation and injection of source code into
1363 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1364 to compile the source code to object code, and if successful, inject
1365 and execute that code within the current context of the inferior.
1366 Currently the C language is supported. The commands used to
1367 interface with this new feature are:
1369 compile code [-raw|-r] [--] [source code]
1370 compile file [-raw|-r] filename
1374 demangle [-l language] [--] name
1375 Demangle "name" in the specified language, or the current language
1376 if elided. This command is renamed from the "maint demangle" command.
1377 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1378 as "maint demangler-warning".
1380 queue-signal signal-name-or-number
1381 Queue a signal to be delivered to the thread when it is resumed.
1383 add-auto-load-scripts-directory directory
1384 Add entries to the list of directories from which to load auto-loaded
1387 maint print user-registers
1388 List all currently available "user" registers.
1390 compile code [-r|-raw] [--] [source code]
1391 Compile, inject, and execute in the inferior the executable object
1392 code produced by compiling the provided source code.
1394 compile file [-r|-raw] filename
1395 Compile and inject into the inferior the executable object code
1396 produced by compiling the source code stored in the filename
1399 * On resume, GDB now always passes the signal the program had stopped
1400 for to the thread the signal was sent to, even if the user changed
1401 threads before resuming. Previously GDB would often (but not
1402 always) deliver the signal to the thread that happens to be current
1405 * Conversely, the "signal" command now consistently delivers the
1406 requested signal to the current thread. GDB now asks for
1407 confirmation if the program had stopped for a signal and the user
1408 switched threads meanwhile.
1410 * "breakpoint always-inserted" modes "off" and "auto" merged.
1412 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1413 won't remove breakpoints from the target until all threads stop,
1414 even in non-stop mode. The "auto" mode has been removed, and "off"
1415 is now the default mode.
1419 set debug symbol-lookup
1420 show debug symbol-lookup
1421 Control display of debugging info regarding symbol lookup.
1425 ** The -list-thread-groups command outputs an exit-code field for
1426 inferiors that have exited.
1430 MIPS SDE mips*-sde*-elf*
1434 Support for these obsolete configurations has been removed.
1436 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1437 SGI Irix-5.x mips-*-irix5*
1438 SGI Irix-6.x mips-*-irix6*
1439 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1440 VAX running Ultrix vax-*-ultrix*
1442 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1443 and "assf"), have been removed. Use the "sharedlibrary" command, or
1444 its alias "share", instead.
1446 *** Changes in GDB 7.8
1448 * New command line options
1451 This is an alias for the --data-directory option.
1453 * GDB supports printing and modifying of variable length automatic arrays
1454 as specified in ISO C99.
1456 * The ARM simulator now supports instruction level tracing
1457 with or without disassembly.
1461 GDB now has support for scripting using Guile. Whether this is
1462 available is determined at configure time.
1463 Guile version 2.0 or greater is required.
1464 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1466 * New commands (for set/show, see "New options" below)
1470 Invoke CODE by passing it to the Guile interpreter.
1474 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1476 info auto-load guile-scripts [regexp]
1477 Print the list of automatically loaded Guile scripts.
1479 * The source command is now capable of sourcing Guile scripts.
1480 This feature is dependent on the debugger being built with Guile support.
1484 set print symbol-loading (off|brief|full)
1485 show print symbol-loading
1486 Control whether to print informational messages when loading symbol
1487 information for a file. The default is "full", but when debugging
1488 programs with large numbers of shared libraries the amount of output
1489 becomes less useful.
1491 set guile print-stack (none|message|full)
1492 show guile print-stack
1493 Show a stack trace when an error is encountered in a Guile script.
1495 set auto-load guile-scripts (on|off)
1496 show auto-load guile-scripts
1497 Control auto-loading of Guile script files.
1499 maint ada set ignore-descriptive-types (on|off)
1500 maint ada show ignore-descriptive-types
1501 Control whether the debugger should ignore descriptive types in Ada
1502 programs. The default is not to ignore the descriptive types. See
1503 the user manual for more details on descriptive types and the intended
1504 usage of this option.
1506 set auto-connect-native-target
1508 Control whether GDB is allowed to automatically connect to the
1509 native target for the run, attach, etc. commands when not connected
1510 to any target yet. See also "target native" below.
1512 set record btrace replay-memory-access (read-only|read-write)
1513 show record btrace replay-memory-access
1514 Control what memory accesses are allowed during replay.
1516 maint set target-async (on|off)
1517 maint show target-async
1518 This controls whether GDB targets operate in synchronous or
1519 asynchronous mode. Normally the default is asynchronous, if it is
1520 available; but this can be changed to more easily debug problems
1521 occurring only in synchronous mode.
1523 set mi-async (on|off)
1525 Control whether MI asynchronous mode is preferred. This supersedes
1526 "set target-async" of previous GDB versions.
1528 * "set target-async" is deprecated as a CLI option and is now an alias
1529 for "set mi-async" (only puts MI into async mode).
1531 * Background execution commands (e.g., "c&", "s&", etc.) are now
1532 possible ``out of the box'' if the target supports them. Previously
1533 the user would need to explicitly enable the possibility with the
1534 "set target-async on" command.
1536 * New features in the GDB remote stub, GDBserver
1538 ** New option --debug-format=option1[,option2,...] allows one to add
1539 additional text to each output. At present only timestamps
1540 are supported: --debug-format=timestamps.
1541 Timestamps can also be turned on with the
1542 "monitor set debug-format timestamps" command from GDB.
1544 * The 'record instruction-history' command now starts counting instructions
1545 at one. This also affects the instruction ranges reported by the
1546 'record function-call-history' command when given the /i modifier.
1548 * The command 'record function-call-history' supports a new modifier '/c' to
1549 indent the function names based on their call stack depth.
1550 The fields for the '/i' and '/l' modifier have been reordered.
1551 The source line range is now prefixed with 'at'.
1552 The instruction range is now prefixed with 'inst'.
1553 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1554 "record instruction-history" and "list" commands.
1556 * The ranges given as arguments to the 'record function-call-history' and
1557 'record instruction-history' commands are now inclusive.
1559 * The btrace record target now supports the 'record goto' command.
1560 For locations inside the execution trace, the back trace is computed
1561 based on the information stored in the execution trace.
1563 * The btrace record target supports limited reverse execution and replay.
1564 The target does not record data and therefore does not allow reading
1565 memory or registers.
1567 * The "catch syscall" command now works on s390*-linux* targets.
1569 * The "compare-sections" command is no longer specific to target
1570 remote. It now works with all targets.
1572 * All native targets are now consistently called "native".
1573 Consequently, the "target child", "target GNU", "target djgpp",
1574 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1575 commands have been replaced with "target native". The QNX/NTO port
1576 leaves the "procfs" target in place and adds a "native" target for
1577 consistency with other ports. The impact on users should be minimal
1578 as these commands previously either throwed an error, or were
1579 no-ops. The target's name is visible in the output of the following
1580 commands: "help target", "info target", "info files", "maint print
1583 * The "target native" command now connects to the native target. This
1584 can be used to launch native programs even when "set
1585 auto-connect-native-target" is set to off.
1587 * GDB now supports access to Intel MPX registers on GNU/Linux.
1589 * Support for Intel AVX-512 registers on GNU/Linux.
1590 Support displaying and modifying Intel AVX-512 registers
1591 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1593 * New remote packets
1595 qXfer:btrace:read's annex
1596 The qXfer:btrace:read packet supports a new annex 'delta' to read
1597 branch trace incrementally.
1601 ** Valid Python operations on gdb.Value objects representing
1602 structs/classes invoke the corresponding overloaded operators if
1604 ** New `Xmethods' feature in the Python API. Xmethods are
1605 additional methods or replacements for existing methods of a C++
1606 class. This feature is useful for those cases where a method
1607 defined in C++ source code could be inlined or optimized out by
1608 the compiler, making it unavailable to GDB.
1611 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1613 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1614 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1615 its alias "share", instead.
1617 * The commands "set remotebaud" and "show remotebaud" are no longer
1618 supported. Use "set serial baud" and "show serial baud" (respectively)
1623 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1624 target-async". The latter is left as a deprecated alias of the
1625 former for backward compatibility. If the target supports it,
1626 CLI background execution commands are now always possible by
1627 default, independently of whether the frontend stated a
1628 preference for asynchronous execution with "-gdb-set mi-async".
1629 Previously "-gdb-set target-async off" affected both MI execution
1630 commands and CLI execution commands.
1632 *** Changes in GDB 7.7
1634 * Improved support for process record-replay and reverse debugging on
1635 arm*-linux* targets. Support for thumb32 and syscall instruction
1636 recording has been added.
1638 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1640 * GDB now supports Fission DWP file format version 2.
1641 http://gcc.gnu.org/wiki/DebugFission
1643 * New convenience function "$_isvoid", to check whether an expression
1644 is void. A void expression is an expression where the type of the
1645 result is "void". For example, some convenience variables may be
1646 "void" when evaluated (e.g., "$_exitcode" before the execution of
1647 the program being debugged; or an undefined convenience variable).
1648 Another example, when calling a function whose return type is
1651 * The "maintenance print objfiles" command now takes an optional regexp.
1653 * The "catch syscall" command now works on arm*-linux* targets.
1655 * GDB now consistently shows "<not saved>" when printing values of
1656 registers the debug info indicates have not been saved in the frame
1657 and there's nowhere to retrieve them from
1658 (callee-saved/call-clobbered registers):
1663 (gdb) info registers rax
1666 Before, the former would print "<optimized out>", and the latter
1667 "*value not available*".
1669 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1674 ** Frame filters and frame decorators have been added.
1675 ** Temporary breakpoints are now supported.
1676 ** Line tables representation has been added.
1677 ** New attribute 'parent_type' for gdb.Field objects.
1678 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1679 ** New attribute 'name' for gdb.Type objects.
1683 Nios II ELF nios2*-*-elf
1684 Nios II GNU/Linux nios2*-*-linux
1685 Texas Instruments MSP430 msp430*-*-elf
1687 * Removed native configurations
1689 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1690 been removed. ELF variants of these configurations are kept supported.
1692 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1693 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1694 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1695 i[34567]86-*-openbsd3.[0-3]
1696 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1697 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1698 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1702 Like "catch throw", but catches a re-thrown exception.
1703 maint check-psymtabs
1704 Renamed from old "maint check-symtabs".
1706 Perform consistency checks on symtabs.
1707 maint expand-symtabs
1708 Expand symtabs matching an optional regexp.
1711 Display the details of GDB configure-time options.
1713 maint set|show per-command
1714 maint set|show per-command space
1715 maint set|show per-command time
1716 maint set|show per-command symtab
1717 Enable display of per-command gdb resource usage.
1719 remove-symbol-file FILENAME
1720 remove-symbol-file -a ADDRESS
1721 Remove a symbol file added via add-symbol-file. The file to remove
1722 can be identified by its filename or by an address that lies within
1723 the boundaries of this symbol file in memory.
1726 info exceptions REGEXP
1727 Display the list of Ada exceptions defined in the program being
1728 debugged. If provided, only the exceptions whose names match REGEXP
1733 set debug symfile off|on
1735 Control display of debugging info regarding reading symbol files and
1736 symbol tables within those files
1738 set print raw frame-arguments
1739 show print raw frame-arguments
1740 Set/show whether to print frame arguments in raw mode,
1741 disregarding any defined pretty-printers.
1743 set remote trace-status-packet
1744 show remote trace-status-packet
1745 Set/show the use of remote protocol qTStatus packet.
1749 Control display of debugging messages related to Nios II targets.
1753 Control whether target-assisted range stepping is enabled.
1755 set startup-with-shell
1756 show startup-with-shell
1757 Specifies whether Unix child processes are started via a shell or
1762 Use the target memory cache for accesses to the code segment. This
1763 improves performance of remote debugging (particularly disassembly).
1765 * You can now use a literal value 'unlimited' for options that
1766 interpret 0 or -1 as meaning "unlimited". E.g., "set
1767 trace-buffer-size unlimited" is now an alias for "set
1768 trace-buffer-size -1" and "set height unlimited" is now an alias for
1771 * The "set debug symtab-create" debugging option of GDB has been changed to
1772 accept a verbosity level. 0 means "off", 1 provides basic debugging
1773 output, and values of 2 or greater provides more verbose output.
1775 * New command-line options
1777 Display the details of GDB configure-time options.
1779 * The command 'tsave' can now support new option '-ctf' to save trace
1780 buffer in Common Trace Format.
1782 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1785 * GDB now implements the the C++ 'typeid' operator.
1787 * The new convenience variable $_exception holds the exception being
1788 thrown or caught at an exception-related catchpoint.
1790 * The exception-related catchpoints, like "catch throw", now accept a
1791 regular expression which can be used to filter exceptions by type.
1793 * The new convenience variable $_exitsignal is automatically set to
1794 the terminating signal number when the program being debugged dies
1795 due to an uncaught signal.
1799 ** All MI commands now accept an optional "--language" option.
1800 Support for this feature can be verified by using the "-list-features"
1801 command, which should contain "language-option".
1803 ** The new command -info-gdb-mi-command allows the user to determine
1804 whether a GDB/MI command is supported or not.
1806 ** The "^error" result record returned when trying to execute an undefined
1807 GDB/MI command now provides a variable named "code" whose content is the
1808 "undefined-command" error code. Support for this feature can be verified
1809 by using the "-list-features" command, which should contain
1810 "undefined-command-error-code".
1812 ** The -trace-save MI command can optionally save trace buffer in Common
1815 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1817 ** The command -data-list-register-values now accepts an optional
1818 "--skip-unavailable" option. When used, only the available registers
1821 ** The new command -trace-frame-collected dumps collected variables,
1822 computed expressions, tvars, memory and registers in a traceframe.
1824 ** The commands -stack-list-locals, -stack-list-arguments and
1825 -stack-list-variables now accept an option "--skip-unavailable".
1826 When used, only the available locals or arguments are displayed.
1828 ** The -exec-run command now accepts an optional "--start" option.
1829 When used, the command follows the same semantics as the "start"
1830 command, stopping the program's execution at the start of its
1831 main subprogram. Support for this feature can be verified using
1832 the "-list-features" command, which should contain
1833 "exec-run-start-option".
1835 ** The new commands -catch-assert and -catch-exceptions insert
1836 catchpoints stopping the program when Ada exceptions are raised.
1838 ** The new command -info-ada-exceptions provides the equivalent of
1839 the new "info exceptions" command.
1841 * New system-wide configuration scripts
1842 A GDB installation now provides scripts suitable for use as system-wide
1843 configuration scripts for the following systems:
1847 * GDB now supports target-assigned range stepping with remote targets.
1848 This improves the performance of stepping source lines by reducing
1849 the number of control packets from/to GDB. See "New remote packets"
1852 * GDB now understands the element 'tvar' in the XML traceframe info.
1853 It has the id of the collected trace state variables.
1855 * On S/390 targets that provide the transactional-execution feature,
1856 the program interruption transaction diagnostic block (TDB) is now
1857 represented as a number of additional "registers" in GDB.
1859 * New remote packets
1863 The vCont packet supports a new 'r' action, that tells the remote
1864 stub to step through an address range itself, without GDB
1865 involvemement at each single-step.
1867 qXfer:libraries-svr4:read's annex
1868 The previously unused annex of the qXfer:libraries-svr4:read packet
1869 is now used to support passing an argument list. The remote stub
1870 reports support for this argument list to GDB's qSupported query.
1871 The defined arguments are "start" and "prev", used to reduce work
1872 necessary for library list updating, resulting in significant
1875 * New features in the GDB remote stub, GDBserver
1877 ** GDBserver now supports target-assisted range stepping. Currently
1878 enabled on x86/x86_64 GNU/Linux targets.
1880 ** GDBserver now adds element 'tvar' in the XML in the reply to
1881 'qXfer:traceframe-info:read'. It has the id of the collected
1882 trace state variables.
1884 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1887 * New 'z' formatter for printing and examining memory, this displays the
1888 value as hexadecimal zero padded on the left to the size of the type.
1890 * GDB can now use Windows x64 unwinding data.
1892 * The "set remotebaud" command has been replaced by "set serial baud".
1893 Similarly, "show remotebaud" has been replaced by "show serial baud".
1894 The "set remotebaud" and "show remotebaud" commands are still available
1895 to provide backward compatibility with older versions of GDB.
1897 *** Changes in GDB 7.6
1899 * Target record has been renamed to record-full.
1900 Record/replay is now enabled with the "record full" command.
1901 This also affects settings that are associated with full record/replay
1902 that have been moved from "set/show record" to "set/show record full":
1904 set|show record full insn-number-max
1905 set|show record full stop-at-limit
1906 set|show record full memory-query
1908 * A new record target "record-btrace" has been added. The new target
1909 uses hardware support to record the control-flow of a process. It
1910 does not support replaying the execution, but it implements the
1911 below new commands for investigating the recorded execution log.
1912 This new recording method can be enabled using:
1916 The "record-btrace" target is only available on Intel Atom processors
1917 and requires a Linux kernel 2.6.32 or later.
1919 * Two new commands have been added for record/replay to give information
1920 about the recorded execution without having to replay the execution.
1921 The commands are only supported by "record btrace".
1923 record instruction-history prints the execution history at
1924 instruction granularity
1926 record function-call-history prints the execution history at
1927 function granularity
1929 * New native configurations
1931 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1932 FreeBSD/powerpc powerpc*-*-freebsd
1933 x86_64/Cygwin x86_64-*-cygwin*
1934 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1938 ARM AArch64 aarch64*-*-elf
1939 ARM AArch64 GNU/Linux aarch64*-*-linux
1940 Lynx 178 PowerPC powerpc-*-lynx*178
1941 x86_64/Cygwin x86_64-*-cygwin*
1942 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1944 * If the configured location of system.gdbinit file (as given by the
1945 --with-system-gdbinit option at configure time) is in the
1946 data-directory (as specified by --with-gdb-datadir at configure
1947 time) or in one of its subdirectories, then GDB will look for the
1948 system-wide init file in the directory specified by the
1949 --data-directory command-line option.
1951 * New command line options:
1953 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1954 other initialization files, unlike -nx which disables all of them.
1956 * Removed command line options
1958 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1961 * The 'ptype' and 'whatis' commands now accept an argument to control
1964 * 'info proc' now works on some core files.
1968 ** Vectors can be created with gdb.Type.vector.
1970 ** Python's atexit.register now works in GDB.
1972 ** Types can be pretty-printed via a Python API.
1974 ** Python 3 is now supported (in addition to Python 2.4 or later)
1976 ** New class gdb.Architecture exposes GDB's internal representation
1977 of architecture in the Python API.
1979 ** New method Frame.architecture returns the gdb.Architecture object
1980 corresponding to the frame's architecture.
1982 * New Python-based convenience functions:
1984 ** $_memeq(buf1, buf2, length)
1985 ** $_streq(str1, str2)
1987 ** $_regex(str, regex)
1989 * The 'cd' command now defaults to using '~' (the home directory) if not
1992 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1993 default for GCC since November 2000.
1995 * The command 'forward-search' can now be abbreviated as 'fo'.
1997 * The command 'info tracepoints' can now display 'installed on target'
1998 or 'not installed on target' for each non-pending location of tracepoint.
2000 * New configure options
2002 --enable-libmcheck/--disable-libmcheck
2003 By default, development versions are built with -lmcheck on hosts
2004 that support it, in order to help track memory corruption issues.
2005 Release versions, on the other hand, are built without -lmcheck
2006 by default. The --enable-libmcheck/--disable-libmcheck configure
2007 options allow the user to override that default.
2008 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2009 This configure option allows the user to build GDB with
2010 libbabeltrace using which GDB can read Common Trace Format data.
2012 * New commands (for set/show, see "New options" below)
2015 Catch signals. This is similar to "handle", but allows commands and
2016 conditions to be attached.
2019 List the BFDs known to GDB.
2021 python-interactive [command]
2023 Start a Python interactive prompt, or evaluate the optional command
2024 and print the result of expressions.
2027 "py" is a new alias for "python".
2029 enable type-printer [name]...
2030 disable type-printer [name]...
2031 Enable or disable type printers.
2035 ** For the Renesas Super-H architecture, the "regs" command has been removed
2036 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2041 set print type methods (on|off)
2042 show print type methods
2043 Control whether method declarations are displayed by "ptype".
2044 The default is to show them.
2046 set print type typedefs (on|off)
2047 show print type typedefs
2048 Control whether typedef definitions are displayed by "ptype".
2049 The default is to show them.
2051 set filename-display basename|relative|absolute
2052 show filename-display
2053 Control the way in which filenames is displayed.
2054 The default is "relative", which preserves previous behavior.
2056 set trace-buffer-size
2057 show trace-buffer-size
2058 Request target to change the size of trace buffer.
2060 set remote trace-buffer-size-packet auto|on|off
2061 show remote trace-buffer-size-packet
2062 Control the use of the remote protocol `QTBuffer:size' packet.
2066 Control display of debugging messages related to ARM AArch64.
2069 set debug coff-pe-read
2070 show debug coff-pe-read
2071 Control display of debugging messages related to reading of COFF/PE
2076 Control display of debugging messages related to Mach-O symbols
2079 set debug notification
2080 show debug notification
2081 Control display of debugging info for async remote notification.
2085 ** Command parameter changes are now notified using new async record
2086 "=cmd-param-changed".
2087 ** Trace frame changes caused by command "tfind" are now notified using
2088 new async record "=traceframe-changed".
2089 ** The creation, deletion and modification of trace state variables
2090 are now notified using new async records "=tsv-created",
2091 "=tsv-deleted" and "=tsv-modified".
2092 ** The start and stop of process record are now notified using new
2093 async record "=record-started" and "=record-stopped".
2094 ** Memory changes are now notified using new async record
2096 ** The data-disassemble command response will include a "fullname" field
2097 containing the absolute file name when source has been requested.
2098 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2099 command, to allow pattern filling of memory areas.
2100 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2101 library load/unload events.
2102 ** The response to breakpoint commands and breakpoint async records
2103 includes an "installed" field containing a boolean state about each
2104 non-pending tracepoint location is whether installed on target or not.
2105 ** Output of the "-trace-status" command includes a "trace-file" field
2106 containing the name of the trace file being examined. This field is
2107 optional, and only present when examining a trace file.
2108 ** The "fullname" field is now always present along with the "file" field,
2109 even if the file cannot be found by GDB.
2111 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2112 You must have the LZMA library available when configuring GDB for this
2113 feature to be enabled. For more information, see:
2114 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2116 * New remote packets
2119 Set the size of trace buffer. The remote stub reports support for this
2120 packet to gdb's qSupported query.
2123 Enable Branch Trace Store (BTS)-based branch tracing for the current
2124 thread. The remote stub reports support for this packet to gdb's
2128 Disable branch tracing for the current thread. The remote stub reports
2129 support for this packet to gdb's qSupported query.
2132 Read the traced branches for the current thread. The remote stub
2133 reports support for this packet to gdb's qSupported query.
2135 *** Changes in GDB 7.5
2137 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2138 for more x32 ABI info.
2140 * GDB now supports access to MIPS DSP registers on Linux targets.
2142 * GDB now supports debugging microMIPS binaries.
2144 * The "info os" command on GNU/Linux can now display information on
2145 several new classes of objects managed by the operating system:
2146 "info os procgroups" lists process groups
2147 "info os files" lists file descriptors
2148 "info os sockets" lists internet-domain sockets
2149 "info os shm" lists shared-memory regions
2150 "info os semaphores" lists semaphores
2151 "info os msg" lists message queues
2152 "info os modules" lists loaded kernel modules
2154 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2155 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2156 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2157 options and inspect the probe arguments using the new $_probe_arg family
2158 of convenience variables. You can obtain more information about SystemTap
2159 in <http://sourceware.org/systemtap/>.
2161 * GDB now supports reversible debugging on ARM, it allows you to
2162 debug basic ARM and THUMB instructions, and provides
2163 record/replay support.
2165 * The option "symbol-reloading" has been deleted as it is no longer used.
2169 ** GDB commands implemented in Python can now be put in command class
2172 ** The "maint set python print-stack on|off" is now deleted.
2174 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2175 apply "flag enum"-style pretty-printing to any enum.
2177 ** gdb.lookup_symbol can now work when there is no current frame.
2179 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2180 the source at which the symbol was defined.
2182 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2183 method 'value'. The former indicates whether the symbol needs a
2184 frame in order to compute its value, and the latter computes the
2187 ** A new method 'referenced_value' on gdb.Value objects which can
2188 dereference pointer as well as C++ reference values.
2190 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2191 which return the global and static blocks (as gdb.Block objects),
2192 of the underlying symbol table, respectively.
2194 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2195 object associated with a PC value.
2197 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2198 of the address range occupied by code for the current source line.
2200 * Go language support.
2201 GDB now supports debugging programs written in the Go programming
2204 * GDBserver now supports stdio connections.
2205 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2207 * The binary "gdbtui" can no longer be built or installed.
2208 Use "gdb -tui" instead.
2210 * GDB will now print "flag" enums specially. A flag enum is one where
2211 all the enumerator values have no bits in common when pairwise
2212 "and"ed. When printing a value whose type is a flag enum, GDB will
2213 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2214 (gdb) print (enum E) 3
2217 * The filename part of a linespec will now match trailing components
2218 of a source file name. For example, "break gcc/expr.c:1000" will
2219 now set a breakpoint in build/gcc/expr.c, but not
2220 build/libcpp/expr.c.
2222 * The "info proc" and "generate-core-file" commands will now also
2223 work on remote targets connected to GDBserver on Linux.
2225 * The command "info catch" has been removed. It has been disabled
2226 since December 2007.
2228 * The "catch exception" and "catch assert" commands now accept
2229 a condition at the end of the command, much like the "break"
2230 command does. For instance:
2232 (gdb) catch exception Constraint_Error if Barrier = True
2234 Previously, it was possible to add a condition to such catchpoints,
2235 but it had to be done as a second step, after the catchpoint had been
2236 created, using the "condition" command.
2238 * The "info static-tracepoint-marker" command will now also work on
2239 native Linux targets with in-process agent.
2241 * GDB can now set breakpoints on inlined functions.
2243 * The .gdb_index section has been updated to include symbols for
2244 inlined functions. GDB will ignore older .gdb_index sections by
2245 default, which could cause symbol files to be loaded more slowly
2246 until their .gdb_index sections can be recreated. The new command
2247 "set use-deprecated-index-sections on" will cause GDB to use any older
2248 .gdb_index sections it finds. This will restore performance, but the
2249 ability to set breakpoints on inlined functions will be lost in symbol
2250 files with older .gdb_index sections.
2252 The .gdb_index section has also been updated to record more information
2253 about each symbol. This speeds up the "info variables", "info functions"
2254 and "info types" commands when used with programs having the .gdb_index
2255 section, as well as speeding up debugging with shared libraries using
2256 the .gdb_index section.
2258 * Ada support for GDB/MI Variable Objects has been added.
2260 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2265 ** New command -info-os is the MI equivalent of "info os".
2267 ** Output logs ("set logging" and related) now include MI output.
2271 ** "set use-deprecated-index-sections on|off"
2272 "show use-deprecated-index-sections on|off"
2273 Controls the use of deprecated .gdb_index sections.
2275 ** "catch load" and "catch unload" can be used to stop when a shared
2276 library is loaded or unloaded, respectively.
2278 ** "enable count" can be used to auto-disable a breakpoint after
2281 ** "info vtbl" can be used to show the virtual method tables for
2282 C++ and Java objects.
2284 ** "explore" and its sub commands "explore value" and "explore type"
2285 can be used to recursively explore values and types of
2286 expressions. These commands are available only if GDB is
2287 configured with '--with-python'.
2289 ** "info auto-load" shows status of all kinds of auto-loaded files,
2290 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2291 sequences of commands files, "info auto-load python-scripts"
2292 shows status of auto-loading Python script files,
2293 "info auto-load local-gdbinit" shows status of loading init file
2294 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2295 status of inferior specific thread debugging shared library loading.
2297 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2298 and "show auto-load-scripts" commands have been deprecated, use their
2299 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2300 and "show auto-load python-scripts" counterparts instead.
2302 ** "dprintf location,format,args..." creates a dynamic printf, which
2303 is basically a breakpoint that does a printf and immediately
2304 resumes your program's execution, so it is like a printf that you
2305 can insert dynamically at runtime instead of at compiletime.
2307 ** "set print symbol"
2309 Controls whether GDB attempts to display the symbol, if any,
2310 corresponding to addresses it prints. This defaults to "on", but
2311 you can set it to "off" to restore GDB's previous behavior.
2313 * Deprecated commands
2315 ** For the Renesas Super-H architecture, the "regs" command has been
2316 deprecated, and "info all-registers" should be used instead.
2320 Renesas RL78 rl78-*-elf
2321 HP OpenVMS ia64 ia64-hp-openvms*
2323 * GDBserver supports evaluation of breakpoint conditions. When
2324 support is advertised by GDBserver, GDB may be told to send the
2325 breakpoint conditions in bytecode form to GDBserver. GDBserver
2326 will only report the breakpoint trigger to GDB when its condition
2331 set mips compression
2332 show mips compression
2333 Select the compressed ISA encoding used in functions that have no symbol
2334 information available. The encoding can be set to either of:
2337 and is updated automatically from ELF file flags if available.
2339 set breakpoint condition-evaluation
2340 show breakpoint condition-evaluation
2341 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2342 GDBserver ("target"). Default option "auto" chooses the most efficient
2344 This option can improve debugger efficiency depending on the speed of the
2348 Disable auto-loading globally.
2351 Show auto-loading setting of all kinds of auto-loaded files.
2353 set auto-load gdb-scripts on|off
2354 show auto-load gdb-scripts
2355 Control auto-loading of GDB canned sequences of commands files.
2357 set auto-load python-scripts on|off
2358 show auto-load python-scripts
2359 Control auto-loading of Python script files.
2361 set auto-load local-gdbinit on|off
2362 show auto-load local-gdbinit
2363 Control loading of init file (.gdbinit) from current directory.
2365 set auto-load libthread-db on|off
2366 show auto-load libthread-db
2367 Control auto-loading of inferior specific thread debugging shared library.
2369 set auto-load scripts-directory <dir1>[:<dir2>...]
2370 show auto-load scripts-directory
2371 Set a list of directories from which to load auto-loaded scripts.
2372 Automatically loaded Python scripts and GDB scripts are located in one
2373 of the directories listed by this option.
2374 The delimiter (':' above) may differ according to the host platform.
2376 set auto-load safe-path <dir1>[:<dir2>...]
2377 show auto-load safe-path
2378 Set a list of directories from which it is safe to auto-load files.
2379 The delimiter (':' above) may differ according to the host platform.
2381 set debug auto-load on|off
2382 show debug auto-load
2383 Control display of debugging info for auto-loading the files above.
2385 set dprintf-style gdb|call|agent
2387 Control the way in which a dynamic printf is performed; "gdb"
2388 requests a GDB printf command, while "call" causes dprintf to call a
2389 function in the inferior. "agent" requests that the target agent
2390 (such as GDBserver) do the printing.
2392 set dprintf-function <expr>
2393 show dprintf-function
2394 set dprintf-channel <expr>
2395 show dprintf-channel
2396 Set the function and optional first argument to the call when using
2397 the "call" style of dynamic printf.
2399 set disconnected-dprintf on|off
2400 show disconnected-dprintf
2401 Control whether agent-style dynamic printfs continue to be in effect
2402 after GDB disconnects.
2404 * New configure options
2406 --with-auto-load-dir
2407 Configure default value for the 'set auto-load scripts-directory'
2408 setting above. It defaults to '$debugdir:$datadir/auto-load',
2409 $debugdir representing global debugging info directories (available
2410 via 'show debug-file-directory') and $datadir representing GDB's data
2411 directory (available via 'show data-directory').
2413 --with-auto-load-safe-path
2414 Configure default value for the 'set auto-load safe-path' setting
2415 above. It defaults to the --with-auto-load-dir setting.
2417 --without-auto-load-safe-path
2418 Set 'set auto-load safe-path' to '/', effectively disabling this
2421 * New remote packets
2423 z0/z1 conditional breakpoints extension
2425 The z0/z1 breakpoint insertion packets have been extended to carry
2426 a list of conditional expressions over to the remote stub depending on the
2427 condition evaluation mode. The use of this extension can be controlled
2428 via the "set remote conditional-breakpoints-packet" command.
2432 Specify the signals which the remote stub may pass to the debugged
2433 program without GDB involvement.
2435 * New command line options
2437 --init-command=FILE, -ix Like --command, -x but execute it
2438 before loading inferior.
2439 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2440 execute it before loading inferior.
2442 *** Changes in GDB 7.4
2444 * GDB now handles ambiguous linespecs more consistently; the existing
2445 FILE:LINE support has been expanded to other types of linespecs. A
2446 breakpoint will now be set on all matching locations in all
2447 inferiors, and locations will be added or removed according to
2450 * GDB now allows you to skip uninteresting functions and files when
2451 stepping with the "skip function" and "skip file" commands.
2453 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2454 and "show remote hardware-watchpoint-length-limit". These allows to
2455 set or show the maximum length limit (in bytes) of a remote
2456 target hardware watchpoint.
2458 This allows e.g. to use "unlimited" hardware watchpoints with the
2459 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2460 watchpoints are slower than real hardware watchpoints but are
2461 significantly faster than gdb software watchpoints.
2465 ** The register_pretty_printer function in module gdb.printing now takes
2466 an optional `replace' argument. If True, the new printer replaces any
2469 ** The "maint set python print-stack on|off" command has been
2470 deprecated and will be deleted in GDB 7.5.
2471 A new command: "set python print-stack none|full|message" has
2472 replaced it. Additionally, the default for "print-stack" is
2473 now "message", which just prints the error message without
2476 ** A prompt substitution hook (prompt_hook) is now available to the
2479 ** A new Python module, gdb.prompt has been added to the GDB Python
2480 modules library. This module provides functionality for
2481 escape sequences in prompts (used by set/show
2482 extended-prompt). These escape sequences are replaced by their
2483 corresponding value.
2485 ** Python commands and convenience-functions located in
2486 'data-directory'/python/gdb/command and
2487 'data-directory'/python/gdb/function are now automatically loaded
2490 ** Blocks now provide four new attributes. global_block and
2491 static_block will return the global and static blocks
2492 respectively. is_static and is_global are boolean attributes
2493 that indicate if the block is one of those two types.
2495 ** Symbols now provide the "type" attribute, the type of the symbol.
2497 ** The "gdb.breakpoint" function has been deprecated in favor of
2500 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2501 of a function. This class is based on the "finish" command
2502 available in the CLI.
2504 ** Type objects for struct and union types now allow access to
2505 the fields using standard Python dictionary (mapping) methods.
2506 For example, "some_type['myfield']" now works, as does
2507 "some_type.items()".
2509 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2512 ** A new function, "deep_items" has been added to the gdb.types
2513 module in the GDB Python modules library. This function returns
2514 an iterator over the fields of a struct or union type. Unlike
2515 the standard Python "iteritems" method, it will recursively traverse
2516 any anonymous fields.
2520 ** "*stopped" events can report several new "reason"s, such as
2523 ** Breakpoint changes are now notified using new async records, like
2524 "=breakpoint-modified".
2526 ** New command -ada-task-info.
2528 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2529 $sdir specifies the default system locations of shared libraries.
2530 $pdir specifies the directory where the libpthread used by the application
2533 GDB no longer looks in $sdir and $pdir after it has searched the directories
2534 mentioned in libthread-db-search-path. If you want to search those
2535 directories, they must be specified in libthread-db-search-path.
2536 The default value of libthread-db-search-path on GNU/Linux and Solaris
2537 systems is now "$sdir:$pdir".
2539 $pdir is not supported by gdbserver, it is currently ignored.
2540 $sdir is supported by gdbserver.
2542 * New configure option --with-iconv-bin.
2543 When using the internationalization support like the one in the GNU C
2544 library, GDB will invoke the "iconv" program to get a list of supported
2545 character sets. If this program lives in a non-standard location, one can
2546 use this option to specify where to find it.
2548 * When natively debugging programs on PowerPC BookE processors running
2549 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2550 watchpoints, which specify a mask in addition to an address to watch.
2551 The mask specifies that some bits of an address (the bits which are
2552 reset in the mask) should be ignored when matching the address accessed
2553 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2554 section in the user manual for more details.
2556 * The new option --once causes GDBserver to stop listening for connections once
2557 the first connection is made. The listening port used by GDBserver will
2558 become available after that.
2560 * New commands "info macros" and "alias" have been added.
2562 * New function parameters suffix @entry specifies value of function parameter
2563 at the time the function got called. Entry values are available only since
2569 "!" is now an alias of the "shell" command.
2570 Note that no space is needed between "!" and SHELL COMMAND.
2574 watch EXPRESSION mask MASK_VALUE
2575 The watch command now supports the mask argument which allows creation
2576 of masked watchpoints, if the current architecture supports this feature.
2578 info auto-load-scripts [REGEXP]
2579 This command was formerly named "maintenance print section-scripts".
2580 It is now generally useful and is no longer a maintenance-only command.
2582 info macro [-all] [--] MACRO
2583 The info macro command has new options `-all' and `--'. The first for
2584 printing all definitions of a macro. The second for explicitly specifying
2585 the end of arguments and the beginning of the macro name in case the macro
2586 name starts with a hyphen.
2588 collect[/s] EXPRESSIONS
2589 The tracepoint collect command now takes an optional modifier "/s"
2590 that directs it to dereference pointer-to-character types and
2591 collect the bytes of memory up to a zero byte. The behavior is
2592 similar to what you see when you use the regular print command on a
2593 string. An optional integer following the "/s" sets a bound on the
2594 number of bytes that will be collected.
2597 The trace start command now interprets any supplied arguments as a
2598 note to be recorded with the trace run, with an effect similar to
2599 setting the variable trace-notes.
2602 The trace stop command now interprets any arguments as a note to be
2603 mentioned along with the tstatus report that the trace was stopped
2604 with a command. The effect is similar to setting the variable
2607 * Tracepoints can now be enabled and disabled at any time after a trace
2608 experiment has been started using the standard "enable" and "disable"
2609 commands. It is now possible to start a trace experiment with no enabled
2610 tracepoints; GDB will display a warning, but will allow the experiment to
2611 begin, assuming that tracepoints will be enabled as needed while the trace
2614 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2615 locations with 4-byte instructions, when they were previously
2616 limited to locations with instructions of 5 bytes or longer.
2620 set debug dwarf2-read
2621 show debug dwarf2-read
2622 Turns on or off display of debugging messages related to reading
2623 DWARF debug info. The default is off.
2625 set debug symtab-create
2626 show debug symtab-create
2627 Turns on or off display of debugging messages related to symbol table
2628 creation. The default is off.
2631 show extended-prompt
2632 Set the GDB prompt, and allow escape sequences to be inserted to
2633 display miscellaneous information (see 'help set extended-prompt'
2634 for the list of sequences). This prompt (and any information
2635 accessed through the escape sequences) is updated every time the
2636 prompt is displayed.
2638 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2639 show print entry-values
2640 Set printing of frame argument values at function entry. In some cases
2641 GDB can determine the value of function argument which was passed by the
2642 function caller, even if the value was modified inside the called function.
2644 set debug entry-values
2645 show debug entry-values
2646 Control display of debugging info for determining frame argument values at
2647 function entry and virtual tail call frames.
2649 set basenames-may-differ
2650 show basenames-may-differ
2651 Set whether a source file may have multiple base names.
2652 (A "base name" is the name of a file with the directory part removed.
2653 Example: The base name of "/home/user/hello.c" is "hello.c".)
2654 If set, GDB will canonicalize file names (e.g., expand symlinks)
2655 before comparing them. Canonicalization is an expensive operation,
2656 but it allows the same file be known by more than one base name.
2657 If not set (the default), all source files are assumed to have just
2658 one base name, and gdb will do file name comparisons more efficiently.
2664 Set a user name and notes for the current and any future trace runs.
2665 This is useful for long-running and/or disconnected traces, to
2666 inform others (or yourself) as to who is running the trace, supply
2667 contact information, or otherwise explain what is going on.
2669 set trace-stop-notes
2670 show trace-stop-notes
2671 Set a note attached to the trace run, that is displayed when the
2672 trace has been stopped by a tstop command. This is useful for
2673 instance as an explanation, if you are stopping a trace run that was
2674 started by someone else.
2676 * New remote packets
2680 Dynamically enable a tracepoint in a started trace experiment.
2684 Dynamically disable a tracepoint in a started trace experiment.
2688 Set the user and notes of the trace run.
2692 Query the current status of a tracepoint.
2696 Query the minimum length of instruction at which a fast tracepoint may
2699 * Dcache size (number of lines) and line-size are now runtime-configurable
2700 via "set dcache line" and "set dcache line-size" commands.
2704 Texas Instruments TMS320C6x tic6x-*-*
2708 Renesas RL78 rl78-*-elf
2710 *** Changes in GDB 7.3.1
2712 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2714 *** Changes in GDB 7.3
2716 * GDB has a new command: "thread find [REGEXP]".
2717 It finds the thread id whose name, target id, or thread extra info
2718 matches the given regular expression.
2720 * The "catch syscall" command now works on mips*-linux* targets.
2722 * The -data-disassemble MI command now supports modes 2 and 3 for
2723 dumping the instruction opcodes.
2725 * New command line options
2727 -data-directory DIR Specify DIR as the "data-directory".
2728 This is mostly for testing purposes.
2730 * The "maint set python auto-load on|off" command has been renamed to
2731 "set auto-load-scripts on|off".
2733 * GDB has a new command: "set directories".
2734 It is like the "dir" command except that it replaces the
2735 source path list instead of augmenting it.
2737 * GDB now understands thread names.
2739 On GNU/Linux, "info threads" will display the thread name as set by
2740 prctl or pthread_setname_np.
2742 There is also a new command, "thread name", which can be used to
2743 assign a name internally for GDB to display.
2746 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2747 has been integrated into GDB.
2751 ** The function gdb.Write now accepts an optional keyword 'stream'.
2752 This keyword, when provided, will direct the output to either
2753 stdout, stderr, or GDB's logging output.
2755 ** Parameters can now be be sub-classed in Python, and in particular
2756 you may implement the get_set_doc and get_show_doc functions.
2757 This improves how Parameter set/show documentation is processed
2758 and allows for more dynamic content.
2760 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2761 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2762 have an is_valid method.
2764 ** Breakpoints can now be sub-classed in Python, and in particular
2765 you may implement a 'stop' function that is executed each time
2766 the inferior reaches that breakpoint.
2768 ** New function gdb.lookup_global_symbol looks up a global symbol.
2770 ** GDB values in Python are now callable if the value represents a
2771 function. For example, if 'some_value' represents a function that
2772 takes two integer parameters and returns a value, you can call
2773 that function like so:
2775 result = some_value (10,20)
2777 ** Module gdb.types has been added.
2778 It contains a collection of utilities for working with gdb.Types objects:
2779 get_basic_type, has_field, make_enum_dict.
2781 ** Module gdb.printing has been added.
2782 It contains utilities for writing and registering pretty-printers.
2783 New classes: PrettyPrinter, SubPrettyPrinter,
2784 RegexpCollectionPrettyPrinter.
2785 New function: register_pretty_printer.
2787 ** New commands "info pretty-printers", "enable pretty-printer" and
2788 "disable pretty-printer" have been added.
2790 ** gdb.parameter("directories") is now available.
2792 ** New function gdb.newest_frame returns the newest frame in the
2795 ** The gdb.InferiorThread class has a new "name" attribute. This
2796 holds the thread's name.
2798 ** Python Support for Inferior events.
2799 Python scripts can add observers to be notified of events
2800 occurring in the process being debugged.
2801 The following events are currently supported:
2802 - gdb.events.cont Continue event.
2803 - gdb.events.exited Inferior exited event.
2804 - gdb.events.stop Signal received, and Breakpoint hit events.
2808 ** GDB now puts template parameters in scope when debugging in an
2809 instantiation. For example, if you have:
2811 template<int X> int func (void) { return X; }
2813 then if you step into func<5>, "print X" will show "5". This
2814 feature requires proper debuginfo support from the compiler; it
2815 was added to GCC 4.5.
2817 ** The motion commands "next", "finish", "until", and "advance" now
2818 work better when exceptions are thrown. In particular, GDB will
2819 no longer lose control of the inferior; instead, the GDB will
2820 stop the inferior at the point at which the exception is caught.
2821 This functionality requires a change in the exception handling
2822 code that was introduced in GCC 4.5.
2824 * GDB now follows GCC's rules on accessing volatile objects when
2825 reading or writing target state during expression evaluation.
2826 One notable difference to prior behavior is that "print x = 0"
2827 no longer generates a read of x; the value of the assignment is
2828 now always taken directly from the value being assigned.
2830 * GDB now has some support for using labels in the program's source in
2831 linespecs. For instance, you can use "advance label" to continue
2832 execution to a label.
2834 * GDB now has support for reading and writing a new .gdb_index
2835 section. This section holds a fast index of DWARF debugging
2836 information and can be used to greatly speed up GDB startup and
2837 operation. See the documentation for `save gdb-index' for details.
2839 * The "watch" command now accepts an optional "-location" argument.
2840 When used, this causes GDB to watch the memory referred to by the
2841 expression. Such a watchpoint is never deleted due to it going out
2844 * GDB now supports thread debugging of core dumps on GNU/Linux.
2846 GDB now activates thread debugging using the libthread_db library
2847 when debugging GNU/Linux core dumps, similarly to when debugging
2848 live processes. As a result, when debugging a core dump file, GDB
2849 is now able to display pthread_t ids of threads. For example, "info
2850 threads" shows the same output as when debugging the process when it
2851 was live. In earlier releases, you'd see something like this:
2854 * 1 LWP 6780 main () at main.c:10
2856 While now you see this:
2859 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2861 It is also now possible to inspect TLS variables when debugging core
2864 When debugging a core dump generated on a machine other than the one
2865 used to run GDB, you may need to point GDB at the correct
2866 libthread_db library with the "set libthread-db-search-path"
2867 command. See the user manual for more details on this command.
2869 * When natively debugging programs on PowerPC BookE processors running
2870 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2871 which stop execution of the inferior whenever it executes an instruction
2872 at any address within the specified range. See the "PowerPC Embedded"
2873 section in the user manual for more details.
2875 * New features in the GDB remote stub, GDBserver
2877 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2878 and i686 LynxOS (version 5.x).
2880 ** GDBserver is now supported on Blackfin Linux.
2882 * New native configurations
2884 ia64 HP-UX ia64-*-hpux*
2888 Analog Devices, Inc. Blackfin Processor bfin-*
2890 * Ada task switching is now supported on sparc-elf targets when
2891 debugging a program using the Ravenscar Profile. For more information,
2892 see the "Tasking Support when using the Ravenscar Profile" section
2893 in the GDB user manual.
2895 * Guile support was removed.
2897 * New features in the GNU simulator
2899 ** The --map-info flag lists all known core mappings.
2901 ** CFI flashes may be simulated via the "cfi" device.
2903 *** Changes in GDB 7.2
2905 * Shared library support for remote targets by default
2907 When GDB is configured for a generic, non-OS specific target, like
2908 for example, --target=arm-eabi or one of the many *-*-elf targets,
2909 GDB now queries remote stubs for loaded shared libraries using the
2910 `qXfer:libraries:read' packet. Previously, shared library support
2911 was always disabled for such configurations.
2915 ** Argument Dependent Lookup (ADL)
2917 In C++ ADL lookup directs function search to the namespaces of its
2918 arguments even if the namespace has not been imported.
2928 Here the compiler will search for `foo' in the namespace of 'b'
2929 and find A::foo. GDB now supports this. This construct is commonly
2930 used in the Standard Template Library for operators.
2932 ** Improved User Defined Operator Support
2934 In addition to member operators, GDB now supports lookup of operators
2935 defined in a namespace and imported with a `using' directive, operators
2936 defined in the global scope, operators imported implicitly from an
2937 anonymous namespace, and the ADL operators mentioned in the previous
2939 GDB now also supports proper overload resolution for all the previously
2940 mentioned flavors of operators.
2942 ** static const class members
2944 Printing of static const class members that are initialized in the
2945 class definition has been fixed.
2947 * Windows Thread Information Block access.
2949 On Windows targets, GDB now supports displaying the Windows Thread
2950 Information Block (TIB) structure. This structure is visible either
2951 by using the new command `info w32 thread-information-block' or, by
2952 dereferencing the new convenience variable named `$_tlb', a
2953 thread-specific pointer to the TIB. This feature is also supported
2954 when remote debugging using GDBserver.
2956 * Static tracepoints
2958 Static tracepoints are calls in the user program into a tracing
2959 library. One such library is a port of the LTTng kernel tracer to
2960 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2961 When debugging with GDBserver, GDB now supports combining the GDB
2962 tracepoint machinery with such libraries. For example: the user can
2963 use GDB to probe a static tracepoint marker (a call from the user
2964 program into the tracing library) with the new "strace" command (see
2965 "New commands" below). This creates a "static tracepoint" in the
2966 breakpoint list, that can be manipulated with the same feature set
2967 as fast and regular tracepoints. E.g., collect registers, local and
2968 global variables, collect trace state variables, and define
2969 tracepoint conditions. In addition, the user can collect extra
2970 static tracepoint marker specific data, by collecting the new
2971 $_sdata internal variable. When analyzing the trace buffer, you can
2972 inspect $_sdata like any other variable available to GDB. For more
2973 information, see the "Tracepoints" chapter in GDB user manual. New
2974 remote packets have been defined to support static tracepoints, see
2975 the "New remote packets" section below.
2977 * Better reconstruction of tracepoints after disconnected tracing
2979 GDB will attempt to download the original source form of tracepoint
2980 definitions when starting a trace run, and then will upload these
2981 upon reconnection to the target, resulting in a more accurate
2982 reconstruction of the tracepoints that are in use on the target.
2986 You can now exercise direct control over the ways that GDB can
2987 affect your program. For instance, you can disallow the setting of
2988 breakpoints, so that the program can run continuously (assuming
2989 non-stop mode). In addition, the "observer" variable is available
2990 to switch all of the different controls; in observer mode, GDB
2991 cannot affect the target's behavior at all, which is useful for
2992 tasks like diagnosing live systems in the field.
2994 * The new convenience variable $_thread holds the number of the
2997 * New remote packets
3001 Return the address of the Windows Thread Information Block of a given thread.
3005 In response to several of the tracepoint packets, the target may now
3006 also respond with a number of intermediate `qRelocInsn' request
3007 packets before the final result packet, to have GDB handle
3008 relocating an instruction to execute at a different address. This
3009 is particularly useful for stubs that support fast tracepoints. GDB
3010 reports support for this feature in the qSupported packet.
3014 List static tracepoint markers in the target program.
3018 List static tracepoint markers at a given address in the target
3021 qXfer:statictrace:read
3023 Read the static trace data collected (by a `collect $_sdata'
3024 tracepoint action). The remote stub reports support for this packet
3025 to gdb's qSupported query.
3029 Send the current settings of GDB's permission flags.
3033 Send part of the source (textual) form of a tracepoint definition,
3034 which includes location, conditional, and action list.
3036 * The source command now accepts a -s option to force searching for the
3037 script in the source search path even if the script name specifies
3040 * New features in the GDB remote stub, GDBserver
3042 - GDBserver now support tracepoints (including fast tracepoints, and
3043 static tracepoints). The feature is currently supported by the
3044 i386-linux and amd64-linux builds. See the "Tracepoints support
3045 in gdbserver" section in the manual for more information.
3047 GDBserver JIT compiles the tracepoint's conditional agent
3048 expression bytecode into native code whenever possible for low
3049 overhead dynamic tracepoints conditionals. For such tracepoints,
3050 an expression that examines program state is evaluated when the
3051 tracepoint is reached, in order to determine whether to capture
3052 trace data. If the condition is simple and false, processing the
3053 tracepoint finishes very quickly and no data is gathered.
3055 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3056 for static tracepoints support.
3058 - GDBserver now supports x86_64 Windows 64-bit debugging.
3060 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3061 it understands register description.
3063 * The --batch flag now disables pagination and queries.
3065 * X86 general purpose registers
3067 GDB now supports reading/writing byte, word and double-word x86
3068 general purpose registers directly. This means you can use, say,
3069 $ah or $ax to refer, respectively, to the byte register AH and
3070 16-bit word register AX that are actually portions of the 32-bit
3071 register EAX or 64-bit register RAX.
3073 * The `commands' command now accepts a range of breakpoints to modify.
3074 A plain `commands' following a command that creates multiple
3075 breakpoints affects all the breakpoints set by that command. This
3076 applies to breakpoints set by `rbreak', and also applies when a
3077 single `break' command creates multiple breakpoints (e.g.,
3078 breakpoints on overloaded c++ functions).
3080 * The `rbreak' command now accepts a filename specification as part of
3081 its argument, limiting the functions selected by the regex to those
3082 in the specified file.
3084 * Support for remote debugging Windows and SymbianOS shared libraries
3085 from Unix hosts has been improved. Non Windows GDB builds now can
3086 understand target reported file names that follow MS-DOS based file
3087 system semantics, such as file names that include drive letters and
3088 use the backslash character as directory separator. This makes it
3089 possible to transparently use the "set sysroot" and "set
3090 solib-search-path" on Unix hosts to point as host copies of the
3091 target's shared libraries. See the new command "set
3092 target-file-system-kind" described below, and the "Commands to
3093 specify files" section in the user manual for more information.
3097 eval template, expressions...
3098 Convert the values of one or more expressions under the control
3099 of the string template to a command line, and call it.
3101 set target-file-system-kind unix|dos-based|auto
3102 show target-file-system-kind
3103 Set or show the assumed file system kind for target reported file
3106 save breakpoints <filename>
3107 Save all current breakpoint definitions to a file suitable for use
3108 in a later debugging session. To read the saved breakpoint
3109 definitions, use the `source' command.
3111 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3114 info static-tracepoint-markers
3115 Display information about static tracepoint markers in the target.
3117 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3118 Define a static tracepoint by probing a marker at the given
3119 function, line, address, or marker ID.
3123 Enable and disable observer mode.
3125 set may-write-registers on|off
3126 set may-write-memory on|off
3127 set may-insert-breakpoints on|off
3128 set may-insert-tracepoints on|off
3129 set may-insert-fast-tracepoints on|off
3130 set may-interrupt on|off
3131 Set individual permissions for GDB effects on the target. Note that
3132 some of these settings can have undesirable or surprising
3133 consequences, particularly when changed in the middle of a session.
3134 For instance, disabling the writing of memory can prevent
3135 breakpoints from being inserted, cause single-stepping to fail, or
3136 even crash your program, if you disable after breakpoints have been
3137 inserted. However, GDB should not crash.
3139 set record memory-query on|off
3140 show record memory-query
3141 Control whether to stop the inferior if memory changes caused
3142 by an instruction cannot be recorded.
3147 The disassemble command now supports "start,+length" form of two arguments.
3151 ** GDB now provides a new directory location, called the python directory,
3152 where Python scripts written for GDB can be installed. The location
3153 of that directory is <data-directory>/python, where <data-directory>
3154 is the GDB data directory. For more details, see section `Scripting
3155 GDB using Python' in the manual.
3157 ** The GDB Python API now has access to breakpoints, symbols, symbol
3158 tables, program spaces, inferiors, threads and frame's code blocks.
3159 Additionally, GDB Parameters can now be created from the API, and
3160 manipulated via set/show in the CLI.
3162 ** New functions gdb.target_charset, gdb.target_wide_charset,
3163 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3165 ** New exception gdb.GdbError.
3167 ** Pretty-printers are now also looked up in the current program space.
3169 ** Pretty-printers can now be individually enabled and disabled.
3171 ** GDB now looks for names of Python scripts to auto-load in a
3172 special section named `.debug_gdb_scripts', in addition to looking
3173 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3175 * Tracepoint actions were unified with breakpoint commands. In particular,
3176 there are no longer differences in "info break" output for breakpoints and
3177 tracepoints and the "commands" command can be used for both tracepoints and
3178 regular breakpoints.
3182 ARM Symbian arm*-*-symbianelf*
3184 * D language support.
3185 GDB now supports debugging programs written in the D programming
3188 * GDB now supports the extended ptrace interface for PowerPC which is
3189 available since Linux kernel version 2.6.34. This automatically enables
3190 any hardware breakpoints and additional hardware watchpoints available in
3191 the processor. The old ptrace interface exposes just one hardware
3192 watchpoint and no hardware breakpoints.
3194 * GDB is now able to use the Data Value Compare (DVC) register available on
3195 embedded PowerPC processors to implement in hardware simple watchpoint
3196 conditions of the form:
3198 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3200 This works in native GDB running on Linux kernels with the extended ptrace
3201 interface mentioned above.
3203 *** Changes in GDB 7.1
3207 ** Namespace Support
3209 GDB now supports importing of namespaces in C++. This enables the
3210 user to inspect variables from imported namespaces. Support for
3211 namepace aliasing has also been added. So, if a namespace is
3212 aliased in the current scope (e.g. namepace C=A; ) the user can
3213 print variables using the alias (e.g. (gdb) print C::x).
3217 All known bugs relating to the printing of virtual base class were
3218 fixed. It is now possible to call overloaded static methods using a
3223 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3224 and reinterpret_cast<> are now handled by the C++ expression parser.
3228 Xilinx MicroBlaze microblaze-*-*
3233 Xilinx MicroBlaze microblaze
3236 * Multi-program debugging.
3238 GDB now has support for multi-program (a.k.a. multi-executable or
3239 multi-exec) debugging. This allows for debugging multiple inferiors
3240 simultaneously each running a different program under the same GDB
3241 session. See "Debugging Multiple Inferiors and Programs" in the
3242 manual for more information. This implied some user visible changes
3243 in the multi-inferior support. For example, "info inferiors" now
3244 lists inferiors that are not running yet or that have exited
3245 already. See also "New commands" and "New options" below.
3247 * New tracing features
3249 GDB's tracepoint facility now includes several new features:
3251 ** Trace state variables
3253 GDB tracepoints now include support for trace state variables, which
3254 are variables managed by the target agent during a tracing
3255 experiment. They are useful for tracepoints that trigger each
3256 other, so for instance one tracepoint can count hits in a variable,
3257 and then a second tracepoint has a condition that is true when the
3258 count reaches a particular value. Trace state variables share the
3259 $-syntax of GDB convenience variables, and can appear in both
3260 tracepoint actions and condition expressions. Use the "tvariable"
3261 command to create, and "info tvariables" to view; see "Trace State
3262 Variables" in the manual for more detail.
3266 GDB now includes an option for defining fast tracepoints, which
3267 targets may implement more efficiently, such as by installing a jump
3268 into the target agent rather than a trap instruction. The resulting
3269 speedup can be by two orders of magnitude or more, although the
3270 tradeoff is that some program locations on some target architectures
3271 might not allow fast tracepoint installation, for instance if the
3272 instruction to be replaced is shorter than the jump. To request a
3273 fast tracepoint, use the "ftrace" command, with syntax identical to
3274 the regular trace command.
3276 ** Disconnected tracing
3278 It is now possible to detach GDB from the target while it is running
3279 a trace experiment, then reconnect later to see how the experiment
3280 is going. In addition, a new variable disconnected-tracing lets you
3281 tell the target agent whether to continue running a trace if the
3282 connection is lost unexpectedly.
3286 GDB now has the ability to save the trace buffer into a file, and
3287 then use that file as a target, similarly to you can do with
3288 corefiles. You can select trace frames, print data that was
3289 collected in them, and use tstatus to display the state of the
3290 tracing run at the moment that it was saved. To create a trace
3291 file, use "tsave <filename>", and to use it, do "target tfile
3294 ** Circular trace buffer
3296 You can ask the target agent to handle the trace buffer as a
3297 circular buffer, discarding the oldest trace frames to make room for
3298 newer ones, by setting circular-trace-buffer to on. This feature may
3299 not be available for all target agents.
3304 The disassemble command, when invoked with two arguments, now requires
3305 the arguments to be comma-separated.
3308 The info variables command now displays variable definitions. Files
3309 which only declare a variable are not shown.
3312 The source command is now capable of sourcing Python scripts.
3313 This feature is dependent on the debugger being build with Python
3316 Related to this enhancement is also the introduction of a new command
3317 "set script-extension" (see below).
3319 * New commands (for set/show, see "New options" below)
3321 record save [<FILENAME>]
3322 Save a file (in core file format) containing the process record
3323 execution log for replay debugging at a later time.
3325 record restore <FILENAME>
3326 Restore the process record execution log that was saved at an
3327 earlier time, for replay debugging.
3329 add-inferior [-copies <N>] [-exec <FILENAME>]
3332 clone-inferior [-copies <N>] [ID]
3333 Make a new inferior ready to execute the same program another
3334 inferior has loaded.
3339 maint info program-spaces
3340 List the program spaces loaded into GDB.
3342 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3343 show remote interrupt-sequence
3344 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3345 as the sequence to the remote target in order to interrupt the execution.
3346 Ctrl-C is a default. Some system prefers BREAK which is high level of
3347 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3348 Magic SysRq g. It is BREAK signal and character 'g'.
3350 set remote interrupt-on-connect [on | off]
3351 show remote interrupt-on-connect
3352 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3353 remote target when gdb connects to it. This is needed when you debug
3356 set remotebreak [on | off]
3358 Deprecated. Use "set/show remote interrupt-sequence" instead.
3360 tvariable $NAME [ = EXP ]
3361 Create or modify a trace state variable.
3364 List trace state variables and their values.
3366 delete tvariable $NAME ...
3367 Delete one or more trace state variables.
3370 Evaluate the given expressions without collecting anything into the
3371 trace buffer. (Valid in tracepoint actions only.)
3373 ftrace FN / FILE:LINE / *ADDR
3374 Define a fast tracepoint at the given function, line, or address.
3376 * New expression syntax
3378 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3379 GDB now parses 0b101010 identically with 42.
3383 set follow-exec-mode new|same
3384 show follow-exec-mode
3385 Control whether GDB reuses the same inferior across an exec call or
3386 creates a new one. This is useful to be able to restart the old
3387 executable after the inferior having done an exec call.
3389 set default-collect EXPR, ...
3390 show default-collect
3391 Define a list of expressions to be collected at each tracepoint.
3392 This is a useful way to ensure essential items are not overlooked,
3393 such as registers or a critical global variable.
3395 set disconnected-tracing
3396 show disconnected-tracing
3397 If set to 1, the target is instructed to continue tracing if it
3398 loses its connection to GDB. If 0, the target is to stop tracing
3401 set circular-trace-buffer
3402 show circular-trace-buffer
3403 If set to on, the target is instructed to use a circular trace buffer
3404 and discard the oldest trace frames instead of stopping the trace due
3405 to a full trace buffer. If set to off, the trace stops when the buffer
3406 fills up. Some targets may not support this.
3408 set script-extension off|soft|strict
3409 show script-extension
3410 If set to "off", the debugger does not perform any script language
3411 recognition, and all sourced files are assumed to be GDB scripts.
3412 If set to "soft" (the default), files are sourced according to
3413 filename extension, falling back to GDB scripts if the first
3415 If set to "strict", files are sourced according to filename extension.
3417 set ada trust-PAD-over-XVS on|off
3418 show ada trust-PAD-over-XVS
3419 If off, activate a workaround against a bug in the debugging information
3420 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3421 the GCC sources for more information about the GNAT encoding and
3422 PAD types in particular). It is always safe to set this option to
3423 off, but this introduces a slight performance penalty. The default
3426 * Python API Improvements
3428 ** GDB provides the new class gdb.LazyString. This is useful in
3429 some pretty-printing cases. The new method gdb.Value.lazy_string
3430 provides a simple way to create objects of this type.
3432 ** The fields returned by gdb.Type.fields now have an
3433 `is_base_class' attribute.
3435 ** The new method gdb.Type.range returns the range of an array type.
3437 ** The new method gdb.parse_and_eval can be used to parse and
3438 evaluate an expression.
3440 * New remote packets
3443 Define a trace state variable.
3446 Get the current value of a trace state variable.
3449 Set desired tracing behavior upon disconnection.
3452 Set the trace buffer to be linear or circular.
3455 Get data about the tracepoints currently in use.
3459 Process record now works correctly with hardware watchpoints.
3461 Multiple bug fixes have been made to the mips-irix port, making it
3462 much more reliable. In particular:
3463 - Debugging threaded applications is now possible again. Previously,
3464 GDB would hang while starting the program, or while waiting for
3465 the program to stop at a breakpoint.
3466 - Attaching to a running process no longer hangs.
3467 - An error occurring while loading a core file has been fixed.
3468 - Changing the value of the PC register now works again. This fixes
3469 problems observed when using the "jump" command, or when calling
3470 a function from GDB, or even when assigning a new value to $pc.
3471 - With the "finish" and "return" commands, the return value for functions
3472 returning a small array is now correctly printed.
3473 - It is now possible to break on shared library code which gets executed
3474 during a shared library init phase (code executed while executing
3475 their .init section). Previously, the breakpoint would have no effect.
3476 - GDB is now able to backtrace through the signal handler for
3477 non-threaded programs.
3479 PIE (Position Independent Executable) programs debugging is now supported.
3480 This includes debugging execution of PIC (Position Independent Code) shared
3481 libraries although for that, it should be possible to run such libraries as an
3484 *** Changes in GDB 7.0
3486 * GDB now has an interface for JIT compilation. Applications that
3487 dynamically generate code can create symbol files in memory and register
3488 them with GDB. For users, the feature should work transparently, and
3489 for JIT developers, the interface is documented in the GDB manual in the
3490 "JIT Compilation Interface" chapter.
3492 * Tracepoints may now be conditional. The syntax is as for
3493 breakpoints; either an "if" clause appended to the "trace" command,
3494 or the "condition" command is available. GDB sends the condition to
3495 the target for evaluation using the same bytecode format as is used
3496 for tracepoint actions.
3498 * The disassemble command now supports: an optional /r modifier, print the
3499 raw instructions in hex as well as in symbolic form, and an optional /m
3500 modifier to print mixed source+assembly.
3502 * Process record and replay
3504 In a architecture environment that supports ``process record and
3505 replay'', ``process record and replay'' target can record a log of
3506 the process execution, and replay it with both forward and reverse
3509 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3510 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3511 set execution-direction {forward|reverse}, for targets that support
3514 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3515 feature is available with a native GDB running on kernel version
3518 * GDB now has support for multi-byte and wide character sets on the
3519 target. Strings whose character type is wchar_t, char16_t, or
3520 char32_t are now correctly printed. GDB supports wide- and unicode-
3521 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3522 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3523 `printf'. This feature requires iconv to work properly; if your
3524 system does not have a working iconv, GDB can use GNU libiconv. See
3525 the installation instructions for more information.
3527 * GDB now supports automatic retrieval of shared library files from
3528 remote targets. To use this feature, specify a system root that begins
3529 with the `remote:' prefix, either via the `set sysroot' command or via
3530 the `--with-sysroot' configure-time option.
3532 * "info sharedlibrary" now takes an optional regex of libraries to show,
3533 and it now reports if a shared library has no debugging information.
3535 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3536 now complete on file names.
3538 * When completing in expressions, gdb will attempt to limit
3539 completions to allowable structure or union fields, where appropriate.
3540 For instance, consider:
3542 # struct example { int f1; double f2; };
3543 # struct example variable;
3546 If the user types TAB at the end of this command line, the available
3547 completions will be "f1" and "f2".
3549 * Inlined functions are now supported. They show up in backtraces, and
3550 the "step", "next", and "finish" commands handle them automatically.
3552 * GDB now supports the token-splicing (##) and stringification (#)
3553 operators when expanding macros. It also supports variable-arity
3556 * GDB now supports inspecting extra signal information, exported by
3557 the new $_siginfo convenience variable. The feature is currently
3558 implemented on linux ARM, i386 and amd64.
3560 * GDB can now display the VFP floating point registers and NEON vector
3561 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3562 can provide these registers (requires Linux 2.6.30 or later). Remote
3563 and simulator targets may also provide them.
3565 * New remote packets
3568 Search memory for a sequence of bytes.
3571 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3572 operation over reliable transport links. Use of this packet is
3573 controlled by the `set remote noack-packet' command.
3576 Kill the process with the specified process ID. Use this in preference
3577 to `k' when multiprocess protocol extensions are supported.
3580 Obtains additional operating system information
3584 Read or write additional signal information.
3586 * Removed remote protocol undocumented extension
3588 An undocumented extension to the remote protocol's `S' stop reply
3589 packet that permited the stub to pass a process id was removed.
3590 Remote servers should use the `T' stop reply packet instead.
3592 * GDB now supports multiple function calling conventions according to the
3593 DWARF-2 DW_AT_calling_convention function attribute.
3595 * The SH target utilizes the aforementioned change to distinguish between gcc
3596 and Renesas calling convention. It also adds the new CLI commands
3597 `set/show sh calling-convention'.
3599 * GDB can now read compressed debug sections, as produced by GNU gold
3600 with the --compress-debug-sections=zlib flag.
3602 * 64-bit core files are now supported on AIX.
3604 * Thread switching is now supported on Tru64.
3606 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3607 which will be allocated using malloc later in program execution.
3609 * The qXfer:libraries:read remote procotol packet now allows passing a
3610 list of section offsets.
3612 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3613 conditions handling signals delivered during attach or thread creation
3614 have also been fixed.
3616 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3617 From the user's standpoint, all unqualified instances of True and False
3618 are treated as the standard definitions, regardless of context.
3620 * GDB now parses C++ symbol and type names more flexibly. For
3623 template<typename T> class C { };
3626 GDB will now correctly handle all of:
3628 ptype C<char const *>
3629 ptype C<char const*>
3630 ptype C<const char *>
3631 ptype C<const char*>
3633 * New features in the GDB remote stub, gdbserver
3635 - The "--wrapper" command-line argument tells gdbserver to use a
3636 wrapper program to launch programs for debugging.
3638 - On PowerPC and S/390 targets, it is now possible to use a single
3639 gdbserver executable to debug both 32-bit and 64-bit programs.
3640 (This requires gdbserver itself to be built as a 64-bit executable.)
3642 - gdbserver uses the new noack protocol mode for TCP connections to
3643 reduce communications latency, if also supported and enabled in GDB.
3645 - Support for the sparc64-linux-gnu target is now included in
3648 - The amd64-linux build of gdbserver now supports debugging both
3649 32-bit and 64-bit programs.
3651 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3652 now support hardware watchpoints, and will use them automatically
3657 GDB now has support for scripting using Python. Whether this is
3658 available is determined at configure time.
3660 New GDB commands can now be written in Python.
3662 * Ada tasking support
3664 Ada tasks can now be inspected in GDB. The following commands have
3668 Print the list of Ada tasks.
3670 Print detailed information about task number N.
3672 Print the task number of the current task.
3674 Switch the context of debugging to task number N.
3676 * Support for user-defined prefixed commands. The "define" command can
3677 add new commands to existing prefixes, e.g. "target".
3679 * Multi-inferior, multi-process debugging.
3681 GDB now has generalized support for multi-inferior debugging. See
3682 "Debugging Multiple Inferiors" in the manual for more information.
3683 Although availability still depends on target support, the command
3684 set is more uniform now. The GNU/Linux specific multi-forks support
3685 has been migrated to this new framework. This implied some user
3686 visible changes; see "New commands" and also "Removed commands"
3689 * Target descriptions can now describe the target OS ABI. See the
3690 "Target Description Format" section in the user manual for more
3693 * Target descriptions can now describe "compatible" architectures
3694 to indicate that the target can execute applications for a different
3695 architecture in addition to those for the main target architecture.
3696 See the "Target Description Format" section in the user manual for
3699 * Multi-architecture debugging.
3701 GDB now includes general supports for debugging applications on
3702 hybrid systems that use more than one single processor architecture
3703 at the same time. Each such hybrid architecture still requires
3704 specific support to be added. The only hybrid architecture supported
3705 in this version of GDB is the Cell Broadband Engine.
3707 * GDB now supports integrated debugging of Cell/B.E. applications that
3708 use both the PPU and SPU architectures. To enable support for hybrid
3709 Cell/B.E. debugging, you need to configure GDB to support both the
3710 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3711 --enable-targets configure option.
3713 * Non-stop mode debugging.
3715 For some targets, GDB now supports an optional mode of operation in
3716 which you can examine stopped threads while other threads continue
3717 to execute freely. This is referred to as non-stop mode, with the
3718 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3719 section in the user manual for more information.
3721 To be able to support remote non-stop debugging, a remote stub needs
3722 to implement the non-stop mode remote protocol extensions, as
3723 described in the "Remote Non-Stop" section of the user manual. The
3724 GDB remote stub, gdbserver, has been adjusted to support these
3725 extensions on linux targets.
3727 * New commands (for set/show, see "New options" below)
3729 catch syscall [NAME(S) | NUMBER(S)]
3730 Catch system calls. Arguments, which should be names of system
3731 calls or their numbers, mean catch only those syscalls. Without
3732 arguments, every syscall will be caught. When the inferior issues
3733 any of the specified syscalls, GDB will stop and announce the system
3734 call, both when it is called and when its call returns. This
3735 feature is currently available with a native GDB running on the
3736 Linux Kernel, under the following architectures: x86, x86_64,
3737 PowerPC and PowerPC64.
3739 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3741 Search memory for a sequence of bytes.
3743 maint set python print-stack
3744 maint show python print-stack
3745 Show a stack trace when an error is encountered in a Python script.
3748 Invoke CODE by passing it to the Python interpreter.
3753 These allow macros to be defined, undefined, and listed
3757 Show operating system information about processes.
3760 List the inferiors currently under GDB's control.
3763 Switch focus to inferior number NUM.
3766 Detach from inferior number NUM.
3769 Kill inferior number NUM.
3773 set spu stop-on-load
3774 show spu stop-on-load
3775 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3777 set spu auto-flush-cache
3778 show spu auto-flush-cache
3779 Control whether to automatically flush the software-managed cache
3780 during Cell/B.E. debugging.
3782 set sh calling-convention
3783 show sh calling-convention
3784 Control the calling convention used when calling SH target functions.
3787 show debug timestamp
3788 Control display of timestamps with GDB debugging output.
3790 set disassemble-next-line
3791 show disassemble-next-line
3792 Control display of disassembled source lines or instructions when
3795 set remote noack-packet
3796 show remote noack-packet
3797 Set/show the use of remote protocol QStartNoAckMode packet. See above
3798 under "New remote packets."
3800 set remote query-attached-packet
3801 show remote query-attached-packet
3802 Control use of remote protocol `qAttached' (query-attached) packet.
3804 set remote read-siginfo-object
3805 show remote read-siginfo-object
3806 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3809 set remote write-siginfo-object
3810 show remote write-siginfo-object
3811 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3814 set remote reverse-continue
3815 show remote reverse-continue
3816 Control use of remote protocol 'bc' (reverse-continue) packet.
3818 set remote reverse-step
3819 show remote reverse-step
3820 Control use of remote protocol 'bs' (reverse-step) packet.
3822 set displaced-stepping
3823 show displaced-stepping
3824 Control displaced stepping mode. Displaced stepping is a way to
3825 single-step over breakpoints without removing them from the debuggee.
3826 Also known as "out-of-line single-stepping".
3829 show debug displaced
3830 Control display of debugging info for displaced stepping.
3832 maint set internal-error
3833 maint show internal-error
3834 Control what GDB does when an internal error is detected.
3836 maint set internal-warning
3837 maint show internal-warning
3838 Control what GDB does when an internal warning is detected.
3843 Use a wrapper program to launch programs for debugging.
3845 set multiple-symbols (all|ask|cancel)
3846 show multiple-symbols
3847 The value of this variable can be changed to adjust the debugger behavior
3848 when an expression or a breakpoint location contains an ambiguous symbol
3849 name (an overloaded function name, for instance).
3851 set breakpoint always-inserted
3852 show breakpoint always-inserted
3853 Keep breakpoints always inserted in the target, as opposed to inserting
3854 them when resuming the target, and removing them when the target stops.
3855 This option can improve debugger performance on slow remote targets.
3857 set arm fallback-mode (arm|thumb|auto)
3858 show arm fallback-mode
3859 set arm force-mode (arm|thumb|auto)
3861 These commands control how ARM GDB determines whether instructions
3862 are ARM or Thumb. The default for both settings is auto, which uses
3863 the current CPSR value for instructions without symbols; previous
3864 versions of GDB behaved as if "set arm fallback-mode arm".
3866 set disable-randomization
3867 show disable-randomization
3868 Standalone programs run with the virtual address space randomization enabled
3869 by default on some platforms. This option keeps the addresses stable across
3870 multiple debugging sessions.
3874 Control whether other threads are stopped or not when some thread hits
3879 Requests that asynchronous execution is enabled in the target, if available.
3880 In this case, it's possible to resume target in the background, and interact
3881 with GDB while the target is running. "show target-async" displays the
3882 current state of asynchronous execution of the target.
3884 set target-wide-charset
3885 show target-wide-charset
3886 The target-wide-charset is the name of the character set that GDB
3887 uses when printing characters whose type is wchar_t.
3889 set tcp auto-retry (on|off)
3891 set tcp connect-timeout
3892 show tcp connect-timeout
3893 These commands allow GDB to retry failed TCP connections to a remote stub
3894 with a specified timeout period; this is useful if the stub is launched
3895 in parallel with GDB but may not be ready to accept connections immediately.
3897 set libthread-db-search-path
3898 show libthread-db-search-path
3899 Control list of directories which GDB will search for appropriate
3902 set schedule-multiple (on|off)
3903 show schedule-multiple
3904 Allow GDB to resume all threads of all processes or only threads of
3905 the current process.
3909 Use more aggressive caching for accesses to the stack. This improves
3910 performance of remote debugging (particularly backtraces) without
3911 affecting correctness.
3913 set interactive-mode (on|off|auto)
3914 show interactive-mode
3915 Control whether GDB runs in interactive mode (on) or not (off).
3916 When in interactive mode, GDB waits for the user to answer all
3917 queries. Otherwise, GDB does not wait and assumes the default
3918 answer. When set to auto (the default), GDB determines which
3919 mode to use based on the stdin settings.
3924 For program forks, this is replaced by the new more generic `info
3925 inferiors' command. To list checkpoints, you can still use the
3926 `info checkpoints' command, which was an alias for the `info forks'
3930 Replaced by the new `inferior' command. To switch between
3931 checkpoints, you can still use the `restart' command, which was an
3932 alias for the `fork' command.
3935 This is removed, since some targets don't have a notion of
3936 processes. To switch between processes, you can still use the
3937 `inferior' command using GDB's own inferior number.
3940 For program forks, this is replaced by the new more generic `kill
3941 inferior' command. To delete a checkpoint, you can still use the
3942 `delete checkpoint' command, which was an alias for the `delete
3946 For program forks, this is replaced by the new more generic `detach
3947 inferior' command. To detach a checkpoint, you can still use the
3948 `detach checkpoint' command, which was an alias for the `detach
3951 * New native configurations
3953 x86/x86_64 Darwin i[34567]86-*-darwin*
3955 x86_64 MinGW x86_64-*-mingw*
3959 Lattice Mico32 lm32-*
3960 x86 DICOS i[34567]86-*-dicos*
3961 x86_64 DICOS x86_64-*-dicos*
3964 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3965 (mingw32ce) debugging.
3971 These commands were actually not implemented on any target.
3973 *** Changes in GDB 6.8
3975 * New native configurations
3977 NetBSD/hppa hppa*-*netbsd*
3978 Xtensa GNU/Linux xtensa*-*-linux*
3982 NetBSD/hppa hppa*-*-netbsd*
3983 Xtensa GNU/Lunux xtensa*-*-linux*
3985 * Change in command line behavior -- corefiles vs. process ids.
3987 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3988 attaching to process NUMBER fails, GDB no longer attempts to open a
3989 core file named NUMBER. Attaching to a program using the -c option
3990 is no longer supported. Instead, use the '-p' or '--pid' options.
3992 * GDB can now be built as a native debugger for debugging Windows x86
3993 (mingw32) Portable Executable (PE) programs.
3995 * Pending breakpoints no longer change their number when their address
3998 * GDB now supports breakpoints with multiple locations,
3999 including breakpoints on C++ constructors, inside C++ templates,
4000 and in inlined functions.
4002 * GDB's ability to debug optimized code has been improved. GDB more
4003 accurately identifies function bodies and lexical blocks that occupy
4004 more than one contiguous range of addresses.
4006 * Target descriptions can now describe registers for PowerPC.
4008 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4009 registers on PowerPC targets.
4011 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4012 targets even when the libthread_db library is not available.
4014 * The GDB remote stub, gdbserver, now supports the new file transfer
4015 commands (remote put, remote get, and remote delete).
4017 * The GDB remote stub, gdbserver, now supports run and attach in
4018 extended-remote mode.
4020 * hppa*64*-*-hpux11* target broken
4021 The debugger is unable to start a program and fails with the following
4022 error: "Error trying to get information about dynamic linker".
4023 The gdb-6.7 release is also affected.
4025 * GDB now supports the --enable-targets= configure option to allow
4026 building a single GDB executable that supports multiple remote
4027 target architectures.
4029 * GDB now supports debugging C and C++ programs which use the
4030 Decimal Floating Point extension. In addition, the PowerPC target
4031 now has a set of pseudo-registers to inspect decimal float values
4032 stored in two consecutive float registers.
4034 * The -break-insert MI command can optionally create pending
4037 * Improved support for debugging Ada
4038 Many improvements to the Ada language support have been made. These
4040 - Better support for Ada2005 interface types
4041 - Improved handling of arrays and slices in general
4042 - Better support for Taft-amendment types
4043 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4045 - Improved command completion in Ada
4048 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4053 set print frame-arguments (all|scalars|none)
4054 show print frame-arguments
4055 The value of this variable can be changed to control which argument
4056 values should be printed by the debugger when displaying a frame.
4061 Transfer files to and from a remote target, and delete remote files.
4068 Transfer files to and from a remote target, and delete remote files.
4070 * New remote packets
4077 Open, close, read, write, and delete files on the remote system.
4080 Attach to an existing process on the remote system, in extended-remote
4084 Run a new process on the remote system, in extended-remote mode.
4086 *** Changes in GDB 6.7
4088 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4089 bfd, libiberty and opcodes, as revealed by static analysis donated by
4090 Coverity, Inc. (http://scan.coverity.com).
4092 * When looking up multiply-defined global symbols, GDB will now prefer the
4093 symbol definition in the current shared library if it was built using the
4094 -Bsymbolic linker option.
4096 * When the Text User Interface (TUI) is not configured, GDB will now
4097 recognize the -tui command-line option and print a message that the TUI
4100 * The GDB remote stub, gdbserver, now has lower overhead for high
4101 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4103 * GDB for MIPS targets now autodetects whether a remote target provides
4104 32-bit or 64-bit register values.
4106 * Support for C++ member pointers has been improved.
4108 * GDB now understands XML target descriptions, which specify the
4109 target's overall architecture. GDB can read a description from
4110 a local file or over the remote serial protocol.
4112 * Vectors of single-byte data use a new integer type which is not
4113 automatically displayed as character or string data.
4115 * The /s format now works with the print command. It displays
4116 arrays of single-byte integers and pointers to single-byte integers
4119 * Target descriptions can now describe target-specific registers,
4120 for architectures which have implemented the support (currently
4121 only ARM, M68K, and MIPS).
4123 * GDB and the GDB remote stub, gdbserver, now support the XScale
4126 * The GDB remote stub, gdbserver, has been updated to support
4127 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4128 has been rewritten to use the standard GDB remote protocol.
4130 * GDB can now step into C++ functions which are called through thunks.
4132 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4134 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4135 layout. It also supports a TextSeg= and DataSeg= response when only
4136 segment base addresses (rather than offsets) are available.
4138 * The /i format now outputs any trailing branch delay slot instructions
4139 immediately following the last instruction within the count specified.
4141 * The GDB remote protocol "T" stop reply packet now supports a
4142 "library" response. Combined with the new "qXfer:libraries:read"
4143 packet, this response allows GDB to debug shared libraries on targets
4144 where the operating system manages the list of loaded libraries (e.g.
4145 Windows and SymbianOS).
4147 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4148 (DLLs) on Windows and Windows CE targets.
4150 * GDB now supports a faster verification that a .debug file matches its binary
4151 according to its build-id signature, if the signature is present.
4157 Enable or disable hardware flow control (RTS/CTS) on the serial port
4158 when debugging using remote targets.
4160 set mem inaccessible-by-default
4161 show mem inaccessible-by-default
4162 If the target supplies a memory map, for instance via the remote
4163 protocol's "qXfer:memory-map:read" packet, setting this variable
4164 prevents GDB from accessing memory outside the memory map. This
4165 is useful for targets with memory mapped registers or which react
4166 badly to accesses of unmapped address space.
4168 set breakpoint auto-hw
4169 show breakpoint auto-hw
4170 If the target supplies a memory map, for instance via the remote
4171 protocol's "qXfer:memory-map:read" packet, setting this variable
4172 lets GDB use hardware breakpoints automatically for memory regions
4173 where it can not use software breakpoints. This covers both the
4174 "break" command and internal breakpoints used for other commands
4175 including "next" and "finish".
4178 catch exception unhandled
4179 Stop the program execution when Ada exceptions are raised.
4182 Stop the program execution when an Ada assertion failed.
4186 Set an alternate system root for target files. This is a more
4187 general version of "set solib-absolute-prefix", which is now
4188 an alias to "set sysroot".
4191 Provide extended SPU facility status information. This set of
4192 commands is available only when debugging the Cell/B.E. SPU
4195 * New native configurations
4197 OpenBSD/sh sh*-*openbsd*
4200 unset tdesc filename
4202 Use the specified local file as an XML target description, and do
4203 not query the target for its built-in description.
4207 OpenBSD/sh sh*-*-openbsd*
4208 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4209 Toshiba Media Processor mep-elf
4211 * New remote packets
4214 Ignore the specified signals; pass them directly to the debugged program
4215 without stopping other threads or reporting them to GDB.
4217 qXfer:features:read:
4218 Read an XML target description from the target, which describes its
4223 Read or write contents of an spufs file on the target system. These
4224 packets are available only on the Cell/B.E. SPU architecture.
4226 qXfer:libraries:read:
4227 Report the loaded shared libraries. Combined with new "T" packet
4228 response, this packet allows GDB to debug shared libraries on
4229 targets where the operating system manages the list of loaded
4230 libraries (e.g. Windows and SymbianOS).
4234 Support for these obsolete configurations has been removed.
4242 i[34567]86-*-lynxos*
4243 i[34567]86-*-netware*
4244 i[34567]86-*-sco3.2v5*
4245 i[34567]86-*-sco3.2v4*
4247 i[34567]86-*-sysv4.2*
4250 i[34567]86-*-unixware2*
4251 i[34567]86-*-unixware*
4260 * Other removed features
4267 Various m68k-only ROM monitors.
4274 Various Renesas ROM monitors and debugging interfaces for SH and
4279 Support for a Macraigor serial interface to on-chip debugging.
4280 GDB does not directly support the newer parallel or USB
4285 A debug information format. The predecessor to DWARF 2 and
4286 DWARF 3, which are still supported.
4288 Support for the HP aCC compiler on HP-UX/PA-RISC
4290 SOM-encapsulated symbolic debugging information, automatic
4291 invocation of pxdb, and the aCC custom C++ ABI. This does not
4292 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4293 with aCC can still be debugged on an assembly level.
4295 MIPS ".pdr" sections
4297 A MIPS-specific format used to describe stack frame layout
4298 in debugging information.
4302 GDB could work with an older version of Guile to debug
4303 the interpreter and Scheme programs running in it.
4305 set mips stack-arg-size
4306 set mips saved-gpreg-size
4308 Use "set mips abi" to control parameter passing for MIPS.
4310 *** Changes in GDB 6.6
4315 Cell Broadband Engine SPU spu-elf
4317 * GDB can now be configured as a cross-debugger targeting native Windows
4318 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4319 running on a Windows system over TCP/IP to debug Windows programs.
4321 * The GDB remote stub, gdbserver, has been updated to support Windows and
4322 Cygwin debugging. Both single-threaded and multi-threaded programs are
4325 * The "set trust-readonly-sections" command works again. This command was
4326 broken in GDB 6.3, 6.4, and 6.5.
4328 * The "load" command now supports writing to flash memory, if the remote
4329 stub provides the required support.
4331 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4332 longer requires symbolic debug information (e.g. DWARF-2).
4337 unset substitute-path
4338 show substitute-path
4339 Manage a list of substitution rules that GDB uses to rewrite the name
4340 of the directories where the sources are located. This can be useful
4341 for instance when the sources were moved to a different location
4342 between compilation and debugging.
4346 Print each CLI command as it is executed. Each command is prefixed with
4347 a number of `+' symbols representing the nesting depth.
4348 The source command now has a `-v' option to enable the same feature.
4352 The ARM Demon monitor support (RDP protocol, "target rdp").
4354 Kernel Object Display, an embedded debugging feature which only worked with
4355 an obsolete version of Cisco IOS.
4357 The 'set download-write-size' and 'show download-write-size' commands.
4359 * New remote packets
4362 Tell a stub about GDB client features, and request remote target features.
4363 The first feature implemented is PacketSize, which allows the target to
4364 specify the size of packets it can handle - to minimize the number of
4365 packets required and improve performance when connected to a remote
4369 Fetch an OS auxilliary vector from the remote stub. This packet is a
4370 more efficient replacement for qPart:auxv:read.
4372 qXfer:memory-map:read:
4373 Fetch a memory map from the remote stub, including information about
4374 RAM, ROM, and flash memory devices.
4379 Erase and program a flash memory device.
4381 * Removed remote packets
4384 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4385 used it, and only gdbserver implemented it.
4387 *** Changes in GDB 6.5
4391 Renesas M32C/M16C m32c-elf
4393 Morpho Technologies ms1 ms1-elf
4397 init-if-undefined Initialize a convenience variable, but
4398 only if it doesn't already have a value.
4400 The following commands are presently only implemented for native GNU/Linux:
4402 checkpoint Save a snapshot of the program state.
4404 restart <n> Return the program state to a
4405 previously saved state.
4407 info checkpoints List currently saved checkpoints.
4409 delete-checkpoint <n> Delete a previously saved checkpoint.
4411 set|show detach-on-fork Tell gdb whether to detach from a newly
4412 forked process, or to keep debugging it.
4414 info forks List forks of the user program that
4415 are available to be debugged.
4417 fork <n> Switch to debugging one of several
4418 forks of the user program that are
4419 available to be debugged.
4421 delete-fork <n> Delete a fork from the list of forks
4422 that are available to be debugged (and
4423 kill the forked process).
4425 detach-fork <n> Delete a fork from the list of forks
4426 that are available to be debugged (and
4427 allow the process to continue).
4431 Morpho Technologies ms2 ms1-elf
4433 * Improved Windows host support
4435 GDB now builds as a cross debugger hosted on i686-mingw32, including
4436 native console support, and remote communications using either
4437 network sockets or serial ports.
4439 * Improved Modula-2 language support
4441 GDB can now print most types in the Modula-2 syntax. This includes:
4442 basic types, set types, record types, enumerated types, range types,
4443 pointer types and ARRAY types. Procedure var parameters are correctly
4444 printed and hexadecimal addresses and character constants are also
4445 written in the Modula-2 syntax. Best results can be obtained by using
4446 GNU Modula-2 together with the -gdwarf-2 command line option.
4450 The ARM rdi-share module.
4452 The Netware NLM debug server.
4454 *** Changes in GDB 6.4
4456 * New native configurations
4458 OpenBSD/arm arm*-*-openbsd*
4459 OpenBSD/mips64 mips64-*-openbsd*
4463 Morpho Technologies ms1 ms1-elf
4465 * New command line options
4467 --batch-silent As for --batch, but totally silent.
4468 --return-child-result The debugger will exist with the same value
4469 the child (debugged) program exited with.
4470 --eval-command COMMAND, -ex COMMAND
4471 Execute a single GDB CLI command. This may be
4472 specified multiple times and in conjunction
4473 with the --command (-x) option.
4475 * Deprecated commands removed
4477 The following commands, that were deprecated in 2000, have been
4481 set|show arm disassembly-flavor set|show arm disassembler
4482 othernames set arm disassembler
4483 set|show remotedebug set|show debug remote
4484 set|show archdebug set|show debug arch
4485 set|show eventdebug set|show debug event
4488 * New BSD user-level threads support
4490 It is now possible to debug programs using the user-level threads
4491 library on OpenBSD and FreeBSD. Currently supported (target)
4494 FreeBSD/amd64 x86_64-*-freebsd*
4495 FreeBSD/i386 i386-*-freebsd*
4496 OpenBSD/i386 i386-*-openbsd*
4498 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4499 are not yet supported.
4501 * New support for Matsushita MN10300 w/sim added
4502 (Work in progress). mn10300-elf.
4504 * REMOVED configurations and files
4506 VxWorks and the XDR protocol *-*-vxworks
4507 Motorola MCORE mcore-*-*
4508 National Semiconductor NS32000 ns32k-*-*
4510 * New "set print array-indexes" command
4512 After turning this setting "on", GDB prints the index of each element
4513 when displaying arrays. The default is "off" to preserve the previous
4516 * VAX floating point support
4518 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4520 * User-defined command support
4522 In addition to using $arg0..$arg9 for argument passing, it is now possible
4523 to use $argc to determine now many arguments have been passed. See the
4524 section on user-defined commands in the user manual for more information.
4526 *** Changes in GDB 6.3:
4528 * New command line option
4530 GDB now accepts -l followed by a number to set the timeout for remote
4533 * GDB works with GCC -feliminate-dwarf2-dups
4535 GDB now supports a more compact representation of DWARF-2 debug
4536 information using DW_FORM_ref_addr references. These are produced
4537 by GCC with the option -feliminate-dwarf2-dups and also by some
4538 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4539 to use -feliminate-dwarf2-dups.
4541 * Internationalization
4543 When supported by the host system, GDB will be built with
4544 internationalization (libintl). The task of marking up the sources is
4545 continued, we're looking forward to our first translation.
4549 Initial support for debugging programs compiled with the GNAT
4550 implementation of the Ada programming language has been integrated
4551 into GDB. In this release, support is limited to expression evaluation.
4553 * New native configurations
4555 GNU/Linux/m32r m32r-*-linux-gnu
4559 GDB's remote protocol now includes support for the 'p' packet. This
4560 packet is used to fetch individual registers from a remote inferior.
4562 * END-OF-LIFE registers[] compatibility module
4564 GDB's internal register infrastructure has been completely rewritten.
4565 The new infrastructure making possible the implementation of key new
4566 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4569 GDB 6.3 will be the last release to include the the registers[]
4570 compatibility module that allowed out-of-date configurations to
4571 continue to work. This change directly impacts the following
4581 powerpc bdm protocol
4583 Unless there is activity to revive these configurations, they will be
4584 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4586 * OBSOLETE configurations and files
4588 Configurations that have been declared obsolete in this release have
4589 been commented out. Unless there is activity to revive these
4590 configurations, the next release of GDB will have their sources
4591 permanently REMOVED.
4600 *** Changes in GDB 6.2.1:
4602 * MIPS `break main; run' gave an heuristic-fence-post warning
4604 When attempting to run even a simple program, a warning about
4605 heuristic-fence-post being hit would be reported. This problem has
4608 * MIPS IRIX 'long double' crashed GDB
4610 When examining a long double variable, GDB would get a segmentation
4611 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4612 IRIX long double values).
4616 A bug in the VAX stack code was causing problems with the "next"
4617 command. This problem has been fixed.
4619 *** Changes in GDB 6.2:
4621 * Fix for ``many threads''
4623 On GNU/Linux systems that use the NPTL threads library, a program
4624 rapidly creating and deleting threads would confuse GDB leading to the
4627 ptrace: No such process.
4628 thread_db_get_info: cannot get thread info: generic error
4630 This problem has been fixed.
4632 * "-async" and "-noasync" options removed.
4634 Support for the broken "-noasync" option has been removed (it caused
4637 * New ``start'' command.
4639 This command runs the program until the begining of the main procedure.
4641 * New BSD Kernel Data Access Library (libkvm) interface
4643 Using ``target kvm'' it is now possible to debug kernel core dumps and
4644 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4645 platforms. Currently supported (native-only) configurations are:
4647 FreeBSD/amd64 x86_64-*-freebsd*
4648 FreeBSD/i386 i?86-*-freebsd*
4649 NetBSD/i386 i?86-*-netbsd*
4650 NetBSD/m68k m68*-*-netbsd*
4651 NetBSD/sparc sparc-*-netbsd*
4652 OpenBSD/amd64 x86_64-*-openbsd*
4653 OpenBSD/i386 i?86-*-openbsd*
4654 OpenBSD/m68k m68*-openbsd*
4655 OpenBSD/sparc sparc-*-openbsd*
4657 * Signal trampoline code overhauled
4659 Many generic problems with GDB's signal handling code have been fixed.
4660 These include: backtraces through non-contiguous stacks; recognition
4661 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4662 call; backtrace through a signal trampoline; step into and out of
4663 signal handlers; and single-stepping in the signal trampoline.
4665 Please note that kernel bugs are a limiting factor here. These
4666 features have been shown to work on an s390 GNU/Linux system that
4667 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4669 * Cygwin support for DWARF 2 added.
4671 * New native configurations
4673 GNU/Linux/hppa hppa*-*-linux*
4674 OpenBSD/hppa hppa*-*-openbsd*
4675 OpenBSD/m68k m68*-*-openbsd*
4676 OpenBSD/m88k m88*-*-openbsd*
4677 OpenBSD/powerpc powerpc-*-openbsd*
4678 NetBSD/vax vax-*-netbsd*
4679 OpenBSD/vax vax-*-openbsd*
4681 * END-OF-LIFE frame compatibility module
4683 GDB's internal frame infrastructure has been completely rewritten.
4684 The new infrastructure making it possible to support key new features
4685 including DWARF 2 Call Frame Information. To aid in the task of
4686 migrating old configurations to this new infrastructure, a
4687 compatibility module, that allowed old configurations to continue to
4688 work, was also included.
4690 GDB 6.2 will be the last release to include this frame compatibility
4691 module. This change directly impacts the following configurations:
4701 Unless there is activity to revive these configurations, they will be
4702 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4704 * REMOVED configurations and files
4706 Sun 3, running SunOS 3 m68*-*-sunos3*
4707 Sun 3, running SunOS 4 m68*-*-sunos4*
4708 Sun 2, running SunOS 3 m68000-*-sunos3*
4709 Sun 2, running SunOS 4 m68000-*-sunos4*
4710 Motorola 680x0 running LynxOS m68*-*-lynxos*
4711 AT&T 3b1/Unix pc m68*-att-*
4712 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4713 decstation mips-dec-* mips-little-*
4714 riscos mips-*-riscos* mips-*-sysv*
4715 sonymips mips-sony-*
4716 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4718 *** Changes in GDB 6.1.1:
4720 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4722 The TUI (Text-mode User Interface) is now built as part of a default
4723 GDB configuration. It is enabled by either selecting the TUI with the
4724 command line option "-i=tui" or by running the separate "gdbtui"
4725 program. For more information on the TUI, see the manual "Debugging
4728 * Pending breakpoint support (also included in GDB 6.1)
4730 Support has been added to allow you to specify breakpoints in shared
4731 libraries that have not yet been loaded. If a breakpoint location
4732 cannot be found, and the "breakpoint pending" option is set to auto,
4733 GDB queries you if you wish to make the breakpoint pending on a future
4734 shared-library load. If and when GDB resolves the breakpoint symbol,
4735 the pending breakpoint is removed as one or more regular breakpoints
4738 Pending breakpoints are very useful for GCJ Java debugging.
4740 * Fixed ISO-C build problems
4742 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4743 non ISO-C code that stopped them being built using a more strict ISO-C
4744 compiler (e.g., IBM's C compiler).
4746 * Fixed build problem on IRIX 5
4748 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4749 wasn't able to compile compile on an IRIX 5 system.
4751 * Added execute permission to gdb/gdbserver/configure
4753 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4754 permission. This bug would cause configure to fail on a number of
4755 systems (Solaris, IRIX). Ref: server/519.
4757 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4759 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4760 has been updated to use constant array sizes.
4762 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4764 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4765 its generated DWARF Call Frame Info. This encoding was causing GDB to
4766 panic, that panic has been fixed. Ref: gdb/1628.
4768 * Fixed a problem when examining parameters in shared library code.
4770 When examining parameters in optimized shared library code generated
4771 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4772 not available''. GDB now correctly displays the variable's value.
4774 *** Changes in GDB 6.1:
4776 * Removed --with-mmalloc
4778 Support for the mmalloc memory manager has been removed, as it
4779 conflicted with the internal gdb byte cache.
4781 * Changes in AMD64 configurations
4783 The AMD64 target now includes the %cs and %ss registers. As a result
4784 the AMD64 remote protocol has changed; this affects the floating-point
4785 and SSE registers. If you rely on those registers for your debugging,
4786 you should upgrade gdbserver on the remote side.
4788 * Revised SPARC target
4790 The SPARC target has been completely revised, incorporating the
4791 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4792 support for LynxOS and SunOS 4 has been dropped. Calling functions
4793 from within GDB on operating systems with a non-executable stack
4794 (Solaris, OpenBSD) now works.
4798 GDB has a new C++ demangler which does a better job on the mangled
4799 names generated by current versions of g++. It also runs faster, so
4800 with this and other changes gdb should now start faster on large C++
4803 * DWARF 2 Location Expressions
4805 GDB support for location expressions has been extended to support function
4806 arguments and frame bases. Older versions of GDB could crash when they
4809 * C++ nested types and namespaces
4811 GDB's support for nested types and namespaces in C++ has been
4812 improved, especially if you use the DWARF 2 debugging format. (This
4813 is the default for recent versions of GCC on most platforms.)
4814 Specifically, if you have a class "Inner" defined within a class or
4815 namespace "Outer", then GDB realizes that the class's name is
4816 "Outer::Inner", not simply "Inner". This should greatly reduce the
4817 frequency of complaints about not finding RTTI symbols. In addition,
4818 if you are stopped at inside of a function defined within a namespace,
4819 GDB modifies its name lookup accordingly.
4821 * New native configurations
4823 NetBSD/amd64 x86_64-*-netbsd*
4824 OpenBSD/amd64 x86_64-*-openbsd*
4825 OpenBSD/alpha alpha*-*-openbsd*
4826 OpenBSD/sparc sparc-*-openbsd*
4827 OpenBSD/sparc64 sparc64-*-openbsd*
4829 * New debugging protocols
4831 M32R with SDI protocol m32r-*-elf*
4833 * "set prompt-escape-char" command deleted.
4835 The command "set prompt-escape-char" has been deleted. This command,
4836 and its very obscure effet on GDB's prompt, was never documented,
4837 tested, nor mentioned in the NEWS file.
4839 * OBSOLETE configurations and files
4841 Configurations that have been declared obsolete in this release have
4842 been commented out. Unless there is activity to revive these
4843 configurations, the next release of GDB will have their sources
4844 permanently REMOVED.
4846 Sun 3, running SunOS 3 m68*-*-sunos3*
4847 Sun 3, running SunOS 4 m68*-*-sunos4*
4848 Sun 2, running SunOS 3 m68000-*-sunos3*
4849 Sun 2, running SunOS 4 m68000-*-sunos4*
4850 Motorola 680x0 running LynxOS m68*-*-lynxos*
4851 AT&T 3b1/Unix pc m68*-att-*
4852 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4853 decstation mips-dec-* mips-little-*
4854 riscos mips-*-riscos* mips-*-sysv*
4855 sonymips mips-sony-*
4856 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4858 * REMOVED configurations and files
4860 SGI Irix-4.x mips-sgi-irix4 or iris4
4861 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4862 Z8000 simulator z8k-zilog-none or z8ksim
4863 Matsushita MN10200 w/simulator mn10200-*-*
4864 H8/500 simulator h8500-hitachi-hms or h8500hms
4865 HP/PA running BSD hppa*-*-bsd*
4866 HP/PA running OSF/1 hppa*-*-osf*
4867 HP/PA Pro target hppa*-*-pro*
4868 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4869 386BSD i[3456]86-*-bsd*
4870 Sequent family i[3456]86-sequent-sysv4*
4871 i[3456]86-sequent-sysv*
4872 i[3456]86-sequent-bsd*
4873 SPARC running LynxOS sparc-*-lynxos*
4874 SPARC running SunOS 4 sparc-*-sunos4*
4875 Tsqware Sparclet sparclet-*-*
4876 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4878 *** Changes in GDB 6.0:
4882 Support for debugging the Objective-C programming language has been
4883 integrated into GDB.
4885 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4887 DWARF 2's Call Frame Information makes available compiler generated
4888 information that more exactly describes the program's run-time stack.
4889 By using this information, GDB is able to provide more robust stack
4892 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4893 have been updated to use a new backtrace mechanism which includes
4894 DWARF 2 CFI support.
4898 GDB's remote protocol has been extended to include support for hosted
4899 file I/O (where the remote target uses GDB's file system). See GDB's
4900 remote protocol documentation for details.
4902 * All targets using the new architecture framework.
4904 All of GDB's targets have been updated to use the new internal
4905 architecture framework. The way is now open for future GDB releases
4906 to include cross-architecture native debugging support (i386 on amd64,
4909 * GNU/Linux's Thread Local Storage (TLS)
4911 GDB now includes support for for the GNU/Linux implementation of
4912 per-thread variables.
4914 * GNU/Linux's Native POSIX Thread Library (NPTL)
4916 GDB's thread code has been updated to work with either the new
4917 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4919 * Separate debug info.
4921 GDB, in conjunction with BINUTILS, now supports a mechanism for
4922 automatically loading debug information from a separate file. Instead
4923 of shipping full debug and non-debug versions of system libraries,
4924 system integrators can now instead ship just the stripped libraries
4925 and optional debug files.
4927 * DWARF 2 Location Expressions
4929 DWARF 2 Location Expressions allow the compiler to more completely
4930 describe the location of variables (even in optimized code) to the
4933 GDB now includes preliminary support for location expressions (support
4934 for DW_OP_piece is still missing).
4938 A number of long standing bugs that caused GDB to die while starting a
4939 Java application have been fixed. GDB's Java support is now
4940 considered "useable".
4942 * GNU/Linux support for fork, vfork, and exec.
4944 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4945 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4948 * GDB supports logging output to a file
4950 There are two new commands, "set logging" and "show logging", which can be
4951 used to capture GDB's output to a file.
4953 * The meaning of "detach" has changed for gdbserver
4955 The "detach" command will now resume the application, as documented. To
4956 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4959 * d10v, m68hc11 `regs' command deprecated
4961 The `info registers' command has been updated so that it displays the
4962 registers using a format identical to the old `regs' command.
4966 A new command, "maint set profile on/off", has been added. This command can
4967 be used to enable or disable profiling while running GDB, to profile a
4968 session or a set of commands. In addition there is a new configure switch,
4969 "--enable-profiling", which will cause GDB to be compiled with profiling
4970 data, for more informative profiling results.
4972 * Default MI syntax changed to "mi2".
4974 The default MI (machine interface) syntax, enabled by the command line
4975 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4976 "mi1", can be enabled by specifying the option "-i=mi1".
4978 Support for the original "mi0" syntax (included in GDB 5.0) has been
4981 Fix for gdb/192: removed extraneous space when displaying frame level.
4982 Fix for gdb/672: update changelist is now output in mi list format.
4983 Fix for gdb/702: a -var-assign that updates the value now shows up
4984 in a subsequent -var-update.
4986 * New native configurations.
4988 FreeBSD/amd64 x86_64-*-freebsd*
4990 * Multi-arched targets.
4992 HP/PA HPUX11 hppa*-*-hpux*
4993 Renesas M32R/D w/simulator m32r-*-elf*
4995 * OBSOLETE configurations and files
4997 Configurations that have been declared obsolete in this release have
4998 been commented out. Unless there is activity to revive these
4999 configurations, the next release of GDB will have their sources
5000 permanently REMOVED.
5002 Z8000 simulator z8k-zilog-none or z8ksim
5003 Matsushita MN10200 w/simulator mn10200-*-*
5004 H8/500 simulator h8500-hitachi-hms or h8500hms
5005 HP/PA running BSD hppa*-*-bsd*
5006 HP/PA running OSF/1 hppa*-*-osf*
5007 HP/PA Pro target hppa*-*-pro*
5008 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5009 Sequent family i[3456]86-sequent-sysv4*
5010 i[3456]86-sequent-sysv*
5011 i[3456]86-sequent-bsd*
5012 Tsqware Sparclet sparclet-*-*
5013 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5015 * REMOVED configurations and files
5018 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5019 IBM AIX PS/2 i[3456]86-*-aix
5020 i386 running Mach 3.0 i[3456]86-*-mach3*
5021 i386 running Mach i[3456]86-*-mach*
5022 i386 running OSF/1 i[3456]86-*osf1mk*
5023 HP/Apollo 68k Family m68*-apollo*-sysv*,
5025 m68*-hp-bsd*, m68*-hp-hpux*
5026 Argonaut Risc Chip (ARC) arc-*-*
5027 Mitsubishi D30V d30v-*-*
5028 Fujitsu FR30 fr30-*-elf*
5029 OS/9000 i[34]86-*-os9k
5030 I960 with MON960 i960-*-coff
5032 * MIPS $fp behavior changed
5034 The convenience variable $fp, for the MIPS, now consistently returns
5035 the address of the current frame's base. Previously, depending on the
5036 context, $fp could refer to either $sp or the current frame's base
5037 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5038 The GNU Source-Level Debugger''.
5040 *** Changes in GDB 5.3:
5042 * GNU/Linux shared library multi-threaded performance improved.
5044 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5045 `/proc', in preference to `ptrace' for memory reads. This may result
5046 in an improvement in the start-up time of multi-threaded, shared
5047 library applications when run under GDB. One GDB user writes: ``loads
5048 shared libs like mad''.
5050 * ``gdbserver'' now supports multi-threaded applications on some targets
5052 Support for debugging multi-threaded applications which use
5053 the GNU/Linux LinuxThreads package has been added for
5054 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5055 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5057 * GDB now supports C/C++ preprocessor macros.
5059 GDB now expands preprocessor macro invocations in C/C++ expressions,
5060 and provides various commands for showing macro definitions and how
5063 The new command `macro expand EXPRESSION' expands any macro
5064 invocations in expression, and shows the result.
5066 The new command `show macro MACRO-NAME' shows the definition of the
5067 macro named MACRO-NAME, and where it was defined.
5069 Most compilers don't include information about macros in the debugging
5070 information by default. In GCC 3.1, for example, you need to compile
5071 your program with the options `-gdwarf-2 -g3'. If the macro
5072 information is present in the executable, GDB will read it.
5074 * Multi-arched targets.
5076 DEC Alpha (partial) alpha*-*-*
5077 DEC VAX (partial) vax-*-*
5079 National Semiconductor NS32000 (partial) ns32k-*-*
5080 Motorola 68000 (partial) m68k-*-*
5081 Motorola MCORE mcore-*-*
5085 Fujitsu FRV architecture added by Red Hat frv*-*-*
5088 * New native configurations
5090 Alpha NetBSD alpha*-*-netbsd*
5091 SH NetBSD sh*-*-netbsdelf*
5092 MIPS NetBSD mips*-*-netbsd*
5093 UltraSPARC NetBSD sparc64-*-netbsd*
5095 * OBSOLETE configurations and files
5097 Configurations that have been declared obsolete in this release have
5098 been commented out. Unless there is activity to revive these
5099 configurations, the next release of GDB will have their sources
5100 permanently REMOVED.
5102 Mitsubishi D30V d30v-*-*
5103 OS/9000 i[34]86-*-os9k
5104 IBM AIX PS/2 i[3456]86-*-aix
5105 Fujitsu FR30 fr30-*-elf*
5106 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5107 Argonaut Risc Chip (ARC) arc-*-*
5108 i386 running Mach 3.0 i[3456]86-*-mach3*
5109 i386 running Mach i[3456]86-*-mach*
5110 i386 running OSF/1 i[3456]86-*osf1mk*
5111 HP/Apollo 68k Family m68*-apollo*-sysv*,
5113 m68*-hp-bsd*, m68*-hp-hpux*
5114 I960 with MON960 i960-*-coff
5116 * OBSOLETE languages
5118 CHILL, a Pascal like language used by telecommunications companies.
5120 * REMOVED configurations and files
5122 AMD 29k family via UDI a29k-amd-udi, udi29k
5123 A29K VxWorks a29k-*-vxworks
5124 AMD 29000 embedded, using EBMON a29k-none-none
5125 AMD 29000 embedded with COFF a29k-none-coff
5126 AMD 29000 embedded with a.out a29k-none-aout
5128 testsuite/gdb.hp/gdb.threads-hp/ directory
5130 * New command "set max-user-call-depth <nnn>"
5132 This command allows the user to limit the call depth of user-defined
5133 commands. The default is 1024.
5135 * Changes in FreeBSD/i386 native debugging.
5137 Support for the "generate-core-file" has been added.
5139 * New commands "dump", "append", and "restore".
5141 These commands allow data to be copied from target memory
5142 to a bfd-format or binary file (dump and append), and back
5143 from a file into memory (restore).
5145 * Improved "next/step" support on multi-processor Alpha Tru64.
5147 The previous single-step mechanism could cause unpredictable problems,
5148 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5149 of a software single-step mechanism prevents this.
5151 *** Changes in GDB 5.2.1:
5159 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5160 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5161 Fix, by Joel Brobecker imported from mainline.
5163 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5164 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5165 Fix, by Fred Fish, imported from mainline.
5167 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5168 Surprisingly enough, it works now.
5169 By Michal Ludvig, imported from mainline.
5171 i386 hardware watchpoint support:
5172 avoid misses on second run for some targets.
5173 By Pierre Muller, imported from mainline.
5175 *** Changes in GDB 5.2:
5177 * New command "set trust-readonly-sections on[off]".
5179 This command is a hint that tells gdb that read-only sections
5180 really are read-only (ie. that their contents will not change).
5181 In this mode, gdb will go to the object file rather than the
5182 target to read memory from read-only sections (such as ".text").
5183 This can be a significant performance improvement on some
5184 (notably embedded) targets.
5186 * New command "generate-core-file" (or "gcore").
5188 This new gdb command allows the user to drop a core file of the child
5189 process state at any time. So far it's been implemented only for
5190 GNU/Linux and Solaris, but should be relatively easily ported to other
5191 hosts. Argument is core file name (defaults to core.<pid>).
5193 * New command line option
5195 GDB now accepts --pid or -p followed by a process id.
5197 * Change in command line behavior -- corefiles vs. process ids.
5199 There is a subtle behavior in the way in which GDB handles
5200 command line arguments. The first non-flag argument is always
5201 a program to debug, but the second non-flag argument may either
5202 be a corefile or a process id. Previously, GDB would attempt to
5203 open the second argument as a corefile, and if that failed, would
5204 issue a superfluous error message and then attempt to attach it as
5205 a process. Now, if the second argument begins with a non-digit,
5206 it will be treated as a corefile. If it begins with a digit,
5207 GDB will attempt to attach it as a process, and if no such process
5208 is found, will then attempt to open it as a corefile.
5210 * Changes in ARM configurations.
5212 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5213 configuration is fully multi-arch.
5215 * New native configurations
5217 ARM NetBSD arm*-*-netbsd*
5218 x86 OpenBSD i[3456]86-*-openbsd*
5219 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5220 Sparc64 running FreeBSD sparc64-*-freebsd*
5224 Sanyo XStormy16 xstormy16-elf
5226 * OBSOLETE configurations and files
5228 Configurations that have been declared obsolete in this release have
5229 been commented out. Unless there is activity to revive these
5230 configurations, the next release of GDB will have their sources
5231 permanently REMOVED.
5233 AMD 29k family via UDI a29k-amd-udi, udi29k
5234 A29K VxWorks a29k-*-vxworks
5235 AMD 29000 embedded, using EBMON a29k-none-none
5236 AMD 29000 embedded with COFF a29k-none-coff
5237 AMD 29000 embedded with a.out a29k-none-aout
5239 testsuite/gdb.hp/gdb.threads-hp/ directory
5241 * REMOVED configurations and files
5243 TI TMS320C80 tic80-*-*
5245 PowerPC Solaris powerpcle-*-solaris*
5246 PowerPC Windows NT powerpcle-*-cygwin32
5247 PowerPC Netware powerpc-*-netware*
5248 Harris/CXUX m88k m88*-harris-cxux*
5249 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5250 ns32k-utek-sysv* ns32k-utek-*
5251 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5252 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5253 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5254 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5255 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5257 * Changes to command line processing
5259 The new `--args' feature can be used to specify command-line arguments
5260 for the inferior from gdb's command line.
5262 * Changes to key bindings
5264 There is a new `operate-and-get-next' function bound to `C-o'.
5266 *** Changes in GDB 5.1.1
5268 Fix compile problem on DJGPP.
5270 Fix a problem with floating-point registers on the i386 being
5273 Fix to stop GDB crashing on .debug_str debug info.
5275 Numerous documentation fixes.
5277 Numerous testsuite fixes.
5279 *** Changes in GDB 5.1:
5281 * New native configurations
5283 Alpha FreeBSD alpha*-*-freebsd*
5284 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5285 MIPS GNU/Linux mips*-*-linux*
5286 MIPS SGI Irix 6.x mips*-sgi-irix6*
5287 ia64 AIX ia64-*-aix*
5288 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5292 Motorola 68HC11 and 68HC12 m68hc11-elf
5294 UltraSparc running GNU/Linux sparc64-*-linux*
5296 * OBSOLETE configurations and files
5298 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5299 Harris/CXUX m88k m88*-harris-cxux*
5300 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5301 ns32k-utek-sysv* ns32k-utek-*
5302 TI TMS320C80 tic80-*-*
5304 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5305 PowerPC Solaris powerpcle-*-solaris*
5306 PowerPC Windows NT powerpcle-*-cygwin32
5307 PowerPC Netware powerpc-*-netware*
5308 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5309 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5310 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5311 Apple Macintosh (MPW) host N/A
5313 stuff.c (Program to stuff files into a specially prepared space in kdb)
5314 kdb-start.c (Main loop for the standalone kernel debugger)
5316 Configurations that have been declared obsolete in this release have
5317 been commented out. Unless there is activity to revive these
5318 configurations, the next release of GDB will have their sources
5319 permanently REMOVED.
5321 * REMOVED configurations and files
5323 Altos 3068 m68*-altos-*
5324 Convex c1-*-*, c2-*-*
5326 ARM RISCix arm-*-* (as host)
5330 * GDB has been converted to ISO C.
5332 GDB's source code has been converted to ISO C. In particular, the
5333 sources are fully protoized, and rely on standard headers being
5338 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5340 * The MI enabled by default.
5342 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5343 revised and enabled by default. Packages which use GDB as a debugging
5344 engine behind a UI or another front end are encouraged to switch to
5345 using the GDB/MI interface, instead of the old annotations interface
5346 which is now deprecated.
5348 * Support for debugging Pascal programs.
5350 GDB now includes support for debugging Pascal programs. The following
5351 main features are supported:
5353 - Pascal-specific data types such as sets;
5355 - automatic recognition of Pascal sources based on file-name
5358 - Pascal-style display of data types, variables, and functions;
5360 - a Pascal expression parser.
5362 However, some important features are not yet supported.
5364 - Pascal string operations are not supported at all;
5366 - there are some problems with boolean types;
5368 - Pascal type hexadecimal constants are not supported
5369 because they conflict with the internal variables format;
5371 - support for Pascal objects and classes is not full yet;
5373 - unlike Pascal, GDB is case-sensitive for symbol names.
5375 * Changes in completion.
5377 Commands such as `shell', `run' and `set args', which pass arguments
5378 to inferior programs, now complete on file names, similar to what
5379 users expect at the shell prompt.
5381 Commands which accept locations, such as `disassemble', `print',
5382 `breakpoint', `until', etc. now complete on filenames as well as
5383 program symbols. Thus, if you type "break foob TAB", and the source
5384 files linked into the programs include `foobar.c', that file name will
5385 be one of the candidates for completion. However, file names are not
5386 considered for completion after you typed a colon that delimits a file
5387 name from a name of a function in that file, as in "break foo.c:bar".
5389 `set demangle-style' completes on available demangling styles.
5391 * New platform-independent commands:
5393 It is now possible to define a post-hook for a command as well as a
5394 hook that runs before the command. For more details, see the
5395 documentation of `hookpost' in the GDB manual.
5397 * Changes in GNU/Linux native debugging.
5399 Support for debugging multi-threaded programs has been completely
5400 revised for all platforms except m68k and sparc. You can now debug as
5401 many threads as your system allows you to have.
5403 Attach/detach is supported for multi-threaded programs.
5405 Support for SSE registers was added for x86. This doesn't work for
5406 multi-threaded programs though.
5408 * Changes in MIPS configurations.
5410 Multi-arch support is enabled for all MIPS configurations.
5412 GDB can now be built as native debugger on SGI Irix 6.x systems for
5413 debugging n32 executables. (Debugging 64-bit executables is not yet
5416 * Unified support for hardware watchpoints in all x86 configurations.
5418 Most (if not all) native x86 configurations support hardware-assisted
5419 breakpoints and watchpoints in a unified manner. This support
5420 implements debug register sharing between watchpoints, which allows to
5421 put a virtually infinite number of watchpoints on the same address,
5422 and also supports watching regions up to 16 bytes with several debug
5425 The new maintenance command `maintenance show-debug-regs' toggles
5426 debugging print-outs in functions that insert, remove, and test
5427 watchpoints and hardware breakpoints.
5429 * Changes in the DJGPP native configuration.
5431 New command ``info dos sysinfo'' displays assorted information about
5432 the CPU, OS, memory, and DPMI server.
5434 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5435 display information about segment descriptors stored in GDT, LDT, and
5438 New commands ``info dos pde'' and ``info dos pte'' display entries
5439 from Page Directory and Page Tables (for now works with CWSDPMI only).
5440 New command ``info dos address-pte'' displays the Page Table entry for
5441 a given linear address.
5443 GDB can now pass command lines longer than 126 characters to the
5444 program being debugged (requires an update to the libdbg.a library
5445 which is part of the DJGPP development kit).
5447 DWARF2 debug info is now supported.
5449 It is now possible to `step' and `next' through calls to `longjmp'.
5451 * Changes in documentation.
5453 All GDB documentation was converted to GFDL, the GNU Free
5454 Documentation License.
5456 Tracepoints-related commands are now fully documented in the GDB
5459 TUI, the Text-mode User Interface, is now documented in the manual.
5461 Tracepoints-related commands are now fully documented in the GDB
5464 The "GDB Internals" manual now has an index. It also includes
5465 documentation of `ui_out' functions, GDB coding standards, x86
5466 hardware watchpoints, and memory region attributes.
5468 * GDB's version number moved to ``version.in''
5470 The Makefile variable VERSION has been replaced by the file
5471 ``version.in''. People creating GDB distributions should update the
5472 contents of this file.
5476 GUD support is now a standard part of the EMACS distribution.
5478 *** Changes in GDB 5.0:
5480 * Improved support for debugging FP programs on x86 targets
5482 Unified and much-improved support for debugging floating-point
5483 programs on all x86 targets. In particular, ``info float'' now
5484 displays the FP registers in the same format on all x86 targets, with
5485 greater level of detail.
5487 * Improvements and bugfixes in hardware-assisted watchpoints
5489 It is now possible to watch array elements, struct members, and
5490 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5491 on x86 targets no longer erroneously trigger when the address is
5494 * Improvements in the native DJGPP version of GDB
5496 The distribution now includes all the scripts and auxiliary files
5497 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5498 machines ``out of the box''.
5500 The DJGPP version can now debug programs that use signals. It is
5501 possible to catch signals that happened in the debuggee, deliver
5502 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5503 would kill the program being debugged.) Programs that hook hardware
5504 interrupts (keyboard, timer, etc.) can also be debugged.
5506 It is now possible to debug DJGPP programs that redirect their
5507 standard handles or switch them to raw (as opposed to cooked) mode, or
5508 even close them. The command ``run < foo > bar'' works as expected,
5509 and ``info terminal'' reports useful information about the debuggee's
5510 terminal, including raw/cooked mode, redirection, etc.
5512 The DJGPP version now uses termios functions for console I/O, which
5513 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5516 DOS-style file names with drive letters are now fully supported by
5519 It is now possible to debug DJGPP programs that switch their working
5520 directory. It is also possible to rerun the debuggee any number of
5521 times without restarting GDB; thus, you can use the same setup,
5522 breakpoints, etc. for many debugging sessions.
5524 * New native configurations
5526 ARM GNU/Linux arm*-*-linux*
5527 PowerPC GNU/Linux powerpc-*-linux*
5531 Motorola MCore mcore-*-*
5532 x86 VxWorks i[3456]86-*-vxworks*
5533 PowerPC VxWorks powerpc-*-vxworks*
5534 TI TMS320C80 tic80-*-*
5536 * OBSOLETE configurations
5538 Altos 3068 m68*-altos-*
5539 Convex c1-*-*, c2-*-*
5541 ARM RISCix arm-*-* (as host)
5544 Configurations that have been declared obsolete will be commented out,
5545 but the code will be left in place. If there is no activity to revive
5546 these configurations before the next release of GDB, the sources will
5547 be permanently REMOVED.
5549 * Gould support removed
5551 Support for the Gould PowerNode and NP1 has been removed.
5553 * New features for SVR4
5555 On SVR4 native platforms (such as Solaris), if you attach to a process
5556 without first loading a symbol file, GDB will now attempt to locate and
5557 load symbols from the running process's executable file.
5559 * Many C++ enhancements
5561 C++ support has been greatly improved. Overload resolution now works properly
5562 in almost all cases. RTTI support is on the way.
5564 * Remote targets can connect to a sub-program
5566 A popen(3) style serial-device has been added. This device starts a
5567 sub-process (such as a stand-alone simulator) and then communicates
5568 with that. The sub-program to run is specified using the syntax
5569 ``|<program> <args>'' vis:
5571 (gdb) set remotedebug 1
5572 (gdb) target extended-remote |mn10300-elf-sim program-args
5574 * MIPS 64 remote protocol
5576 A long standing bug in the mips64 remote protocol where by GDB
5577 expected certain 32 bit registers (ex SR) to be transfered as 32
5578 instead of 64 bits has been fixed.
5580 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5581 added to provide backward compatibility with older versions of GDB.
5583 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5585 The command ``set remotebinarydownload'' command has been replaced by
5586 ``set remote X-packet''. Other commands in ``set remote'' family
5587 include ``set remote P-packet''.
5589 * Breakpoint commands accept ranges.
5591 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5592 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5593 ``tracepoint passcount'' also accepts a range of tracepoints.
5595 * ``apropos'' command added.
5597 The ``apropos'' command searches through command names and
5598 documentation strings, printing out matches, making it much easier to
5599 try to find a command that does what you are looking for.
5603 A new machine oriented interface (MI) has been added to GDB. This
5604 interface is designed for debug environments running GDB as a separate
5605 process. This is part of the long term libGDB project. See the
5606 "GDB/MI" chapter of the GDB manual for further information. It can be
5607 enabled by configuring with:
5609 .../configure --enable-gdbmi
5611 *** Changes in GDB-4.18:
5613 * New native configurations
5615 HP-UX 10.20 hppa*-*-hpux10.20
5616 HP-UX 11.x hppa*-*-hpux11.0*
5617 M68K GNU/Linux m68*-*-linux*
5621 Fujitsu FR30 fr30-*-elf*
5622 Intel StrongARM strongarm-*-*
5623 Mitsubishi D30V d30v-*-*
5625 * OBSOLETE configurations
5627 Gould PowerNode, NP1 np1-*-*, pn-*-*
5629 Configurations that have been declared obsolete will be commented out,
5630 but the code will be left in place. If there is no activity to revive
5631 these configurations before the next release of GDB, the sources will
5632 be permanently REMOVED.
5636 As a compatibility experiment, GDB's source files buildsym.h and
5637 buildsym.c have been converted to pure standard C, no longer
5638 containing any K&R compatibility code. We believe that all systems in
5639 use today either come with a standard C compiler, or have a GCC port
5640 available. If this is not true, please report the affected
5641 configuration to bug-gdb@gnu.org immediately. See the README file for
5642 information about getting a standard C compiler if you don't have one
5647 GDB now uses readline 2.2.
5649 * set extension-language
5651 You can now control the mapping between filename extensions and source
5652 languages by using the `set extension-language' command. For instance,
5653 you can ask GDB to treat .c files as C++ by saying
5654 set extension-language .c c++
5655 The command `info extensions' lists all of the recognized extensions
5656 and their associated languages.
5658 * Setting processor type for PowerPC and RS/6000
5660 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5661 you can use the `set processor' command to specify what variant of the
5662 PowerPC family you are debugging. The command
5666 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5667 following PowerPC and RS6000 variants:
5669 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5670 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5672 403GC IBM PowerPC 403GC
5673 505 Motorola PowerPC 505
5674 860 Motorola PowerPC 860 or 850
5675 601 Motorola PowerPC 601
5676 602 Motorola PowerPC 602
5677 603 Motorola/IBM PowerPC 603 or 603e
5678 604 Motorola PowerPC 604 or 604e
5679 750 Motorola/IBM PowerPC 750 or 750
5681 At the moment, this command just tells GDB what to name the
5682 special-purpose processor registers. Since almost all the affected
5683 registers are inaccessible to user-level programs, this command is
5684 only useful for remote debugging in its present form.
5688 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5689 more extensive support for HP-UX. Added features include shared
5690 library support, kernel threads and hardware watchpoints for 11.00,
5691 support for HP's ANSI C and C++ compilers, and a compatibility mode
5692 for xdb and dbx commands.
5696 HP's donation includes the new concept of catchpoints, which is a
5697 generalization of the old catch command. On HP-UX, it is now possible
5698 to catch exec, fork, and vfork, as well as library loading.
5700 This means that the existing catch command has changed; its first
5701 argument now specifies the type of catch to be set up. See the
5702 output of "help catch" for a list of catchpoint types.
5704 * Debugging across forks
5706 On HP-UX, you can choose which process to debug when a fork() happens
5711 HP has donated a curses-based terminal user interface (TUI). To get
5712 it, build with --enable-tui. Although this can be enabled for any
5713 configuration, at present it only works for native HP debugging.
5715 * GDB remote protocol additions
5717 A new protocol packet 'X' that writes binary data is now available.
5718 Default behavior is to try 'X', then drop back to 'M' if the stub
5719 fails to respond. The settable variable `remotebinarydownload'
5720 allows explicit control over the use of 'X'.
5722 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5723 full 64-bit address. The command
5725 set remoteaddresssize 32
5727 can be used to revert to the old behaviour. For existing remote stubs
5728 the change should not be noticed, as the additional address information
5731 In order to assist in debugging stubs, you may use the maintenance
5732 command `packet' to send any text string to the stub. For instance,
5734 maint packet heythere
5736 sends the packet "$heythere#<checksum>". Note that it is very easy to
5737 disrupt a debugging session by sending the wrong packet at the wrong
5740 The compare-sections command allows you to compare section data on the
5741 target to what is in the executable file without uploading or
5742 downloading, by comparing CRC checksums.
5744 * Tracing can collect general expressions
5746 You may now collect general expressions at tracepoints. This requires
5747 further additions to the target-side stub; see tracepoint.c and
5748 doc/agentexpr.texi for further details.
5750 * mask-address variable for Mips
5752 For Mips targets, you may control the zeroing of the upper 32 bits of
5753 a 64-bit address by entering `set mask-address on'. This is mainly
5754 of interest to users of embedded R4xxx and R5xxx processors.
5756 * Higher serial baud rates
5758 GDB's serial code now allows you to specify baud rates 57600, 115200,
5759 230400, and 460800 baud. (Note that your host system may not be able
5760 to achieve all of these rates.)
5764 The i960 configuration now includes an initial implementation of a
5765 builtin simulator, contributed by Jim Wilson.
5768 *** Changes in GDB-4.17:
5770 * New native configurations
5772 Alpha GNU/Linux alpha*-*-linux*
5773 Unixware 2.x i[3456]86-unixware2*
5774 Irix 6.x mips*-sgi-irix6*
5775 PowerPC GNU/Linux powerpc-*-linux*
5776 PowerPC Solaris powerpcle-*-solaris*
5777 Sparc GNU/Linux sparc-*-linux*
5778 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5782 Argonaut Risc Chip (ARC) arc-*-*
5783 Hitachi H8/300S h8300*-*-*
5784 Matsushita MN10200 w/simulator mn10200-*-*
5785 Matsushita MN10300 w/simulator mn10300-*-*
5786 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5787 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5788 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5789 Mitsubishi D10V w/simulator d10v-*-*
5790 Mitsubishi M32R/D w/simulator m32r-*-elf*
5791 Tsqware Sparclet sparclet-*-*
5792 NEC V850 w/simulator v850-*-*
5794 * New debugging protocols
5796 ARM with RDI protocol arm*-*-*
5797 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5798 DDB and LSI variants of PMON protocol mips*-*-*
5799 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5800 PowerPC with SDS protocol powerpc{,le}-*-eabi
5801 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5805 All configurations can now understand and use the DWARF 2 debugging
5806 format. The choice is automatic, if the symbol file contains DWARF 2
5811 GDB now includes basic Java language support. This support is
5812 only useful with Java compilers that produce native machine code.
5814 * solib-absolute-prefix and solib-search-path
5816 For SunOS and SVR4 shared libraries, you may now set the prefix for
5817 loading absolute shared library symbol files, and the search path for
5818 locating non-absolute shared library symbol files.
5820 * Live range splitting
5822 GDB can now effectively debug code for which GCC has performed live
5823 range splitting as part of its optimization. See gdb/doc/LRS for
5824 more details on the expected format of the stabs information.
5828 GDB's support for the GNU Hurd, including thread debugging, has been
5829 updated to work with current versions of the Hurd.
5833 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5834 instruction set. ARM GDB automatically detects when Thumb
5835 instructions are in use, and adjusts disassembly and backtracing
5840 GDB's MIPS target configurations now handle the MIP16 16-bit
5845 GDB now includes support for overlays; if an executable has been
5846 linked such that multiple sections are based at the same address, GDB
5847 will decide which section to use for symbolic info. You can choose to
5848 control the decision manually, using overlay commands, or implement
5849 additional target-side support and use "overlay load-target" to bring
5850 in the overlay mapping. Do "help overlay" for more detail.
5854 The command "info symbol <address>" displays information about
5855 the symbol at the specified address.
5859 The standard remote protocol now includes an extension that allows
5860 asynchronous collection and display of trace data. This requires
5861 extensive support in the target-side debugging stub. Tracing mode
5862 includes a new interaction mode in GDB and new commands: see the
5863 file tracepoint.c for more details.
5867 Configurations for embedded MIPS now include a simulator contributed
5868 by Cygnus Solutions. The simulator supports the instruction sets
5869 of most MIPS variants.
5873 Sparc configurations may now include the ERC32 simulator contributed
5874 by the European Space Agency. The simulator is not built into
5875 Sparc targets by default; configure with --enable-sim to include it.
5879 For target configurations that may include multiple variants of a
5880 basic architecture (such as MIPS and SH), you may now set the
5881 architecture explicitly. "set arch" sets, "info arch" lists
5882 the possible architectures.
5884 *** Changes in GDB-4.16:
5886 * New native configurations
5888 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5889 M68K NetBSD m68k-*-netbsd*
5890 PowerPC AIX 4.x powerpc-*-aix*
5891 PowerPC MacOS powerpc-*-macos*
5892 PowerPC Windows NT powerpcle-*-cygwin32
5893 RS/6000 AIX 4.x rs6000-*-aix4*
5897 ARM with RDP protocol arm-*-*
5898 I960 with MON960 i960-*-coff
5899 MIPS VxWorks mips*-*-vxworks*
5900 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5901 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5903 Matra Sparclet sparclet-*-*
5907 The powerpc-eabi configuration now includes the PSIM simulator,
5908 contributed by Andrew Cagney, with assistance from Mike Meissner.
5909 PSIM is a very elaborate model of the PowerPC, including not only
5910 basic instruction set execution, but also details of execution unit
5911 performance and I/O hardware. See sim/ppc/README for more details.
5915 GDB now works with Solaris 2.5.
5917 * Windows 95/NT native
5919 GDB will now work as a native debugger on Windows 95 and Windows NT.
5920 To build it from source, you must use the "gnu-win32" environment,
5921 which uses a DLL to emulate enough of Unix to run the GNU tools.
5922 Further information, binaries, and sources are available at
5923 ftp.cygnus.com, under pub/gnu-win32.
5925 * dont-repeat command
5927 If a user-defined command includes the command `dont-repeat', then the
5928 command will not be repeated if the user just types return. This is
5929 useful if the command is time-consuming to run, so that accidental
5930 extra keystrokes don't run the same command many times.
5932 * Send break instead of ^C
5934 The standard remote protocol now includes an option to send a break
5935 rather than a ^C to the target in order to interrupt it. By default,
5936 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5938 * Remote protocol timeout
5940 The standard remote protocol includes a new variable `remotetimeout'
5941 that allows you to set the number of seconds before GDB gives up trying
5942 to read from the target. The default value is 2.
5944 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5946 By default GDB will automatically keep track of objects as they are
5947 loaded and unloaded by the dynamic linker. By using the command `set
5948 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5949 when shared library events occur, thus allowing you to set breakpoints
5950 in shared libraries which are explicitly loaded by the inferior.
5952 Note this feature does not work on hpux8. On hpux9 you must link
5953 /usr/lib/end.o into your program. This feature should work
5954 automatically on hpux10.
5956 * Irix 5.x hardware watchpoint support
5958 Irix 5 configurations now support the use of hardware watchpoints.
5960 * Mips protocol "SYN garbage limit"
5962 When debugging a Mips target using the `target mips' protocol, you
5963 may set the number of characters that GDB will ignore by setting
5964 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5965 every character. The default value is 1050.
5967 * Recording and replaying remote debug sessions
5969 If you set `remotelogfile' to the name of a file, gdb will write to it
5970 a recording of a remote debug session. This recording may then be
5971 replayed back to gdb using "gdbreplay". See gdbserver/README for
5972 details. This is useful when you have a problem with GDB while doing
5973 remote debugging; you can make a recording of the session and send it
5974 to someone else, who can then recreate the problem.
5976 * Speedups for remote debugging
5978 GDB includes speedups for downloading and stepping MIPS systems using
5979 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5980 and more efficient S-record downloading.
5982 * Memory use reductions and statistics collection
5984 GDB now uses less memory and reports statistics about memory usage.
5985 Try the `maint print statistics' command, for example.
5987 *** Changes in GDB-4.15:
5989 * Psymtabs for XCOFF
5991 The symbol reader for AIX GDB now uses partial symbol tables. This
5992 can greatly improve startup time, especially for large executables.
5994 * Remote targets use caching
5996 Remote targets now use a data cache to speed up communication with the
5997 remote side. The data cache could lead to incorrect results because
5998 it doesn't know about volatile variables, thus making it impossible to
5999 debug targets which use memory mapped I/O devices. `set remotecache
6000 off' turns the the data cache off.
6002 * Remote targets may have threads
6004 The standard remote protocol now includes support for multiple threads
6005 in the target system, using new protocol commands 'H' and 'T'. See
6006 gdb/remote.c for details.
6010 If GDB is configured with `--enable-netrom', then it will include
6011 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6012 acts as though it is a bank of ROM on the target board, but you can
6013 write into it over the network. GDB's support consists only of
6014 support for fast loading into the emulated ROM; to debug, you must use
6015 another protocol, such as standard remote protocol. The usual
6016 sequence is something like
6018 target nrom <netrom-hostname>
6020 target remote <netrom-hostname>:1235
6024 GDB now includes support for the Apple Macintosh, as a host only. It
6025 may be run as either an MPW tool or as a standalone application, and
6026 it can debug through the serial port. All the usual GDB commands are
6027 available, but to the target command, you must supply "serial" as the
6028 device type instead of "/dev/ttyXX". See mpw-README in the main
6029 directory for more information on how to build. The MPW configuration
6030 scripts */mpw-config.in support only a few targets, and only the
6031 mips-idt-ecoff target has been tested.
6035 GDB configuration now uses autoconf. This is not user-visible,
6036 but does simplify configuration and building.
6040 GDB now supports hpux10.
6042 *** Changes in GDB-4.14:
6044 * New native configurations
6046 x86 FreeBSD i[345]86-*-freebsd
6047 x86 NetBSD i[345]86-*-netbsd
6048 NS32k NetBSD ns32k-*-netbsd
6049 Sparc NetBSD sparc-*-netbsd
6053 A29K VxWorks a29k-*-vxworks
6054 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6055 CPU32 EST-300 emulator m68*-*-est*
6056 PowerPC ELF powerpc-*-elf
6059 * Alpha OSF/1 support for procfs
6061 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6062 possible to attach to running processes. As the mounting of the /proc
6063 filesystem is optional on the Alpha, GDB automatically determines
6064 the availability of /proc during startup. This can lead to problems
6065 if /proc is unmounted after GDB has been started.
6067 * Arguments to user-defined commands
6069 User commands may accept up to 10 arguments separated by whitespace.
6070 Arguments are accessed within the user command via $arg0..$arg9. A
6073 print $arg0 + $arg1 + $arg2
6075 To execute the command use:
6078 Defines the command "adder" which prints the sum of its three arguments.
6079 Note the arguments are text substitutions, so they may reference variables,
6080 use complex expressions, or even perform inferior function calls.
6082 * New `if' and `while' commands
6084 This makes it possible to write more sophisticated user-defined
6085 commands. Both commands take a single argument, which is the
6086 expression to evaluate, and must be followed by the commands to
6087 execute, one per line, if the expression is nonzero, the list being
6088 terminated by the word `end'. The `if' command list may include an
6089 `else' word, which causes the following commands to be executed only
6090 if the expression is zero.
6092 * Fortran source language mode
6094 GDB now includes partial support for Fortran 77. It will recognize
6095 Fortran programs and can evaluate a subset of Fortran expressions, but
6096 variables and functions may not be handled correctly. GDB will work
6097 with G77, but does not yet know much about symbols emitted by other
6100 * Better HPUX support
6102 Most debugging facilities now work on dynamic executables for HPPAs
6103 running hpux9 or later. You can attach to running dynamically linked
6104 processes, but by default the dynamic libraries will be read-only, so
6105 for instance you won't be able to put breakpoints in them. To change
6106 that behavior do the following before running the program:
6112 This will cause the libraries to be mapped private and read-write.
6113 To revert to the normal behavior, do this:
6119 You cannot set breakpoints or examine data in the library until after
6120 the library is loaded if the function/data symbols do not have
6123 GDB can now also read debug symbols produced by the HP C compiler on
6124 HPPAs (sorry, no C++, Fortran or 68k support).
6126 * Target byte order now dynamically selectable
6128 You can choose which byte order to use with a target system, via the
6129 commands "set endian big" and "set endian little", and you can see the
6130 current setting by using "show endian". You can also give the command
6131 "set endian auto", in which case GDB will use the byte order
6132 associated with the executable. Currently, only embedded MIPS
6133 configurations support dynamic selection of target byte order.
6135 * New DOS host serial code
6137 This version uses DPMI interrupts to handle buffered I/O, so you
6138 no longer need to run asynctsr when debugging boards connected to
6141 *** Changes in GDB-4.13:
6143 * New "complete" command
6145 This lists all the possible completions for the rest of the line, if it
6146 were to be given as a command itself. This is intended for use by emacs.
6148 * Trailing space optional in prompt
6150 "set prompt" no longer adds a space for you after the prompt you set. This
6151 allows you to set a prompt which ends in a space or one that does not.
6153 * Breakpoint hit counts
6155 "info break" now displays a count of the number of times the breakpoint
6156 has been hit. This is especially useful in conjunction with "ignore"; you
6157 can ignore a large number of breakpoint hits, look at the breakpoint info
6158 to see how many times the breakpoint was hit, then run again, ignoring one
6159 less than that number, and this will get you quickly to the last hit of
6162 * Ability to stop printing at NULL character
6164 "set print null-stop" will cause GDB to stop printing the characters of
6165 an array when the first NULL is encountered. This is useful when large
6166 arrays actually contain only short strings.
6168 * Shared library breakpoints
6170 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6171 breakpoints in shared libraries before the executable is run.
6173 * Hardware watchpoints
6175 There is a new hardware breakpoint for the watch command for sparclite
6176 targets. See gdb/sparclite/hw_breakpoint.note.
6178 Hardware watchpoints are also now supported under GNU/Linux.
6182 Annotations have been added. These are for use with graphical interfaces,
6183 and are still experimental. Currently only gdba.el uses these.
6185 * Improved Irix 5 support
6187 GDB now works properly with Irix 5.2.
6189 * Improved HPPA support
6191 GDB now works properly with the latest GCC and GAS.
6193 * New native configurations
6195 Sequent PTX4 i[34]86-sequent-ptx4
6196 HPPA running OSF/1 hppa*-*-osf*
6197 Atari TT running SVR4 m68*-*-sysv4*
6198 RS/6000 LynxOS rs6000-*-lynxos*
6202 OS/9000 i[34]86-*-os9k
6203 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6206 * Hitachi SH7000 and E7000-PC ICE support
6208 There is now support for communicating with the Hitachi E7000-PC ICE.
6209 This is available automatically when GDB is configured for the SH.
6213 As usual, a variety of small fixes and improvements, both generic
6214 and configuration-specific. See the ChangeLog for more detail.
6216 *** Changes in GDB-4.12:
6218 * Irix 5 is now supported
6222 GDB-4.12 on the HPPA has a number of changes which make it unable
6223 to debug the output from the currently released versions of GCC and
6224 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6225 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6226 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6229 *** Changes in GDB-4.11:
6231 * User visible changes:
6235 The "set remotedebug" option is now consistent between the mips remote
6236 target, remote targets using the gdb-specific protocol, UDI (AMD's
6237 debug protocol for the 29k) and the 88k bug monitor. It is now an
6238 integer specifying a debug level (normally 0 or 1, but 2 means more
6239 debugging info for the mips target).
6241 * DEC Alpha native support
6243 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6244 debug info, but GDB works fairly well with the DEC compiler and should
6245 work with a future GCC release. See the README file for a few
6246 Alpha-specific notes.
6248 * Preliminary thread implementation
6250 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6252 * LynxOS native and target support for 386
6254 This release has been hosted on LynxOS 2.2, and also can be configured
6255 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6258 * Improvements in C++ mangling/demangling.
6260 This release has much better g++ debugging, specifically in name
6261 mangling/demangling, virtual function calls, print virtual table,
6262 call methods, ...etc.
6264 *** Changes in GDB-4.10:
6266 * User visible changes:
6268 Remote debugging using the GDB-specific (`target remote') protocol now
6269 supports the `load' command. This is only useful if you have some
6270 other way of getting the stub to the target system, and you can put it
6271 somewhere in memory where it won't get clobbered by the download.
6273 Filename completion now works.
6275 When run under emacs mode, the "info line" command now causes the
6276 arrow to point to the line specified. Also, "info line" prints
6277 addresses in symbolic form (as well as hex).
6279 All vxworks based targets now support a user settable option, called
6280 vxworks-timeout. This option represents the number of seconds gdb
6281 should wait for responses to rpc's. You might want to use this if
6282 your vxworks target is, perhaps, a slow software simulator or happens
6283 to be on the far side of a thin network line.
6287 This release contains support for using a DEC alpha as a GDB host for
6288 cross debugging. Native alpha debugging is not supported yet.
6291 *** Changes in GDB-4.9:
6295 This is the first GDB release which is accompanied by a matching testsuite.
6296 The testsuite requires installation of dejagnu, which should be available
6297 via ftp from most sites that carry GNU software.
6301 'Cfront' style demangling has had its name changed to 'ARM' style, to
6302 emphasize that it was written from the specifications in the C++ Annotated
6303 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6304 disclaimers, it still generated too much confusion with users attempting to
6305 use gdb with AT&T cfront.
6309 GDB now uses a standard remote interface to a simulator library.
6310 So far, the library contains simulators for the Zilog Z8001/2, the
6311 Hitachi H8/300, H8/500 and Super-H.
6313 * New targets supported
6315 H8/300 simulator h8300-hitachi-hms or h8300hms
6316 H8/500 simulator h8500-hitachi-hms or h8500hms
6317 SH simulator sh-hitachi-hms or sh
6318 Z8000 simulator z8k-zilog-none or z8ksim
6319 IDT MIPS board over serial line mips-idt-ecoff
6321 Cross-debugging to GO32 targets is supported. It requires a custom
6322 version of the i386-stub.c module which is integrated with the
6323 GO32 memory extender.
6325 * New remote protocols
6327 MIPS remote debugging protocol.
6329 * New source languages supported
6331 This version includes preliminary support for Chill, a Pascal like language
6332 used by telecommunications companies. Chill support is also being integrated
6333 into the GNU compiler, but we don't know when it will be publically available.
6336 *** Changes in GDB-4.8:
6338 * HP Precision Architecture supported
6340 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6341 version of this support was available as a set of patches from the
6342 University of Utah. GDB does not support debugging of programs
6343 compiled with the HP compiler, because HP will not document their file
6344 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6345 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6347 Many problems in the preliminary version have been fixed.
6349 * Faster and better demangling
6351 We have improved template demangling and fixed numerous bugs in the GNU style
6352 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6353 character types (wchar_t) are now supported. Demangling of each symbol is now
6354 only done once, and is cached when the symbol table for a file is read in.
6355 This results in a small increase in memory usage for C programs, a moderate
6356 increase in memory usage for C++ programs, and a fantastic speedup in
6359 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6360 from the specifications in the Annotated Reference Manual, which AT&T's
6361 compiler does not actually implement.
6363 * G++ multiple inheritance compiler problem
6365 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6366 inheritance lattices was reworked to properly discover ambiguities. We
6367 recently found an example which causes this new algorithm to fail in a
6368 very subtle way, producing bad debug information for those classes.
6369 The file 'gcc.patch' (in this directory) can be applied to gcc to
6370 circumvent the problem. A future GCC release will contain a complete
6373 The previous G++ debug info problem (mentioned below for the gdb-4.7
6374 release) is fixed in gcc version 2.3.2.
6376 * Improved configure script
6378 The `configure' script will now attempt to guess your system type if
6379 you don't supply a host system type. The old scheme of supplying a
6380 host system triplet is preferable over using this. All the magic is
6381 done in the new `config.guess' script. Examine it for details.
6383 We have also brought our configure script much more in line with the FSF's
6384 version. It now supports the --with-xxx options. In particular,
6385 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6386 The resulting GDB will not be able to read arbitrary object file formats --
6387 only the format ``expected'' to be used on the configured target system.
6388 We hope to make this the default in a future release.
6390 * Documentation improvements
6392 There's new internal documentation on how to modify GDB, and how to
6393 produce clean changes to the code. We implore people to read it
6394 before submitting changes.
6396 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6397 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6398 `info' files are also provided. To build `info' files from scratch,
6399 you will need the latest `makeinfo' release, which will be available in
6400 a future texinfo-X.Y release.
6402 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6403 We're not sure exactly which versions have this problem, but it has
6404 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6405 or better. If that isn't possible, there is a patch in
6406 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6407 around this problem.
6411 GDB now supports array constants that can be used in expressions typed in by
6412 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6413 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6416 The new directory `gdb/sparclite' contains a program that demonstrates
6417 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6419 * New native hosts supported
6421 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6422 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6424 * New targets supported
6426 AMD 29k family via UDI a29k-amd-udi or udi29k
6428 * New file formats supported
6430 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6431 HPUX core files, and SCO 3.2v2 core files.
6435 Attaching to processes now works again; thanks for the many bug reports.
6437 We have also stomped on a bunch of core dumps caused by
6438 printf_filtered("%s") problems.
6440 We eliminated a copyright problem on the rpc and ptrace header files
6441 for VxWorks, which was discovered at the last minute during the 4.7
6442 release. You should now be able to build a VxWorks GDB.
6444 You can now interrupt gdb while an attached process is running. This
6445 will cause the attached process to stop, and give control back to GDB.
6447 We fixed problems caused by using too many file descriptors
6448 for reading symbols from object files and libraries. This was
6449 especially a problem for programs that used many (~100) shared
6452 The `step' command now only enters a subroutine if there is line number
6453 information for the subroutine. Otherwise it acts like the `next'
6454 command. Previously, `step' would enter subroutines if there was
6455 any debugging information about the routine. This avoids problems
6456 when using `cc -g1' on MIPS machines.
6458 * Internal improvements
6460 GDB's internal interfaces have been improved to make it easier to support
6461 debugging of multiple languages in the future.
6463 GDB now uses a common structure for symbol information internally.
6464 Minimal symbols (derived from linkage symbols in object files), partial
6465 symbols (from a quick scan of debug information), and full symbols
6466 contain a common subset of information, making it easier to write
6467 shared code that handles any of them.
6469 * New command line options
6471 We now accept --silent as an alias for --quiet.
6475 The memory-mapped-malloc library is now licensed under the GNU Library
6476 General Public License.
6478 *** Changes in GDB-4.7:
6480 * Host/native/target split
6482 GDB has had some major internal surgery to untangle the support for
6483 hosts and remote targets. Now, when you configure GDB for a remote
6484 target, it will no longer load in all of the support for debugging
6485 local programs on the host. When fully completed and tested, this will
6486 ensure that arbitrary host/target combinations are possible.
6488 The primary conceptual shift is to separate the non-portable code in
6489 GDB into three categories. Host specific code is required any time GDB
6490 is compiled on that host, regardless of the target. Target specific
6491 code relates to the peculiarities of the target, but can be compiled on
6492 any host. Native specific code is everything else: it can only be
6493 built when the host and target are the same system. Child process
6494 handling and core file support are two common `native' examples.
6496 GDB's use of /proc for controlling Unix child processes is now cleaner.
6497 It has been split out into a single module under the `target_ops' vector,
6498 plus two native-dependent functions for each system that uses /proc.
6500 * New hosts supported
6502 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6503 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6504 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6506 * New targets supported
6508 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6509 68030 and CPU32 m68030-*-*, m68332-*-*
6511 * New native hosts supported
6513 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6514 (386bsd is not well tested yet)
6515 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6517 * New file formats supported
6519 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6520 supports reading of `a.out.adobe' object files, which are an a.out
6521 format extended with minimal information about multiple sections.
6525 `show copying' is the same as the old `info copying'.
6526 `show warranty' is the same as `info warrantee'.
6527 These were renamed for consistency. The old commands continue to work.
6529 `info handle' is a new alias for `info signals'.
6531 You can now define pre-command hooks, which attach arbitrary command
6532 scripts to any command. The commands in the hook will be executed
6533 prior to the user's command. You can also create a hook which will be
6534 executed whenever the program stops. See gdb.texinfo.
6538 We now deal with Cfront style name mangling, and can even extract type
6539 info from mangled symbols. GDB can automatically figure out which
6540 symbol mangling style your C++ compiler uses.
6542 Calling of methods and virtual functions has been improved as well.
6546 The crash that occured when debugging Sun Ansi-C compiled binaries is
6547 fixed. This was due to mishandling of the extra N_SO stabs output
6550 We also finally got Ultrix 4.2 running in house, and fixed core file
6551 support, with help from a dozen people on the net.
6553 John M. Farrell discovered that the reason that single-stepping was so
6554 slow on all of the Mips based platforms (primarily SGI and DEC) was
6555 that we were trying to demangle and lookup a symbol used for internal
6556 purposes on every instruction that was being stepped through. Changing
6557 the name of that symbol so that it couldn't be mistaken for a C++
6558 mangled symbol sped things up a great deal.
6560 Rich Pixley sped up symbol lookups in general by getting much smarter
6561 about when C++ symbol mangling is necessary. This should make symbol
6562 completion (TAB on the command line) much faster. It's not as fast as
6563 we'd like, but it's significantly faster than gdb-4.6.
6567 A new user controllable variable 'call_scratch_address' can
6568 specify the location of a scratch area to be used when GDB
6569 calls a function in the target. This is necessary because the
6570 usual method of putting the scratch area on the stack does not work
6571 in systems that have separate instruction and data spaces.
6573 We integrated changes to support the 29k UDI (Universal Debugger
6574 Interface), but discovered at the last minute that we didn't have all
6575 of the appropriate copyright paperwork. We are working with AMD to
6576 resolve this, and hope to have it available soon.
6580 We have sped up the remote serial line protocol, especially for targets
6581 with lots of registers. It now supports a new `expedited status' ('T')
6582 message which can be used in place of the existing 'S' status message.
6583 This allows the remote stub to send only the registers that GDB
6584 needs to make a quick decision about single-stepping or conditional
6585 breakpoints, eliminating the need to fetch the entire register set for
6586 each instruction being stepped through.
6588 The GDB remote serial protocol now implements a write-through cache for
6589 registers, only re-reading the registers if the target has run.
6591 There is also a new remote serial stub for SPARC processors. You can
6592 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6593 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6594 processor with a serial port.
6598 Configure.in files have become much easier to read and modify. A new
6599 `table driven' format makes it more obvious what configurations are
6600 supported, and what files each one uses.
6604 There is a new opcodes library which will eventually contain all of the
6605 disassembly routines and opcode tables. At present, it only contains
6606 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6607 disassembler (binutils/objdump) to share these routines.
6609 The libiberty library is now copylefted under the GNU Library General
6610 Public License. This allows more liberal use, and was done so libg++
6611 can use it. This makes no difference to GDB, since the Library License
6612 grants all the rights from the General Public License.
6616 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6617 reference to the stabs symbol info used by the debugger. It is (as far
6618 as we know) the only published document on this fascinating topic. We
6619 encourage you to read it, compare it to the stabs information on your
6620 system, and send improvements on the document in general (to
6621 bug-gdb@prep.ai.mit.edu).
6623 And, of course, many bugs have been fixed.
6626 *** Changes in GDB-4.6:
6628 * Better support for C++ function names
6630 GDB now accepts as input the "demangled form" of C++ overloaded function
6631 names and member function names, and can do command completion on such names
6632 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6633 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6634 Make use of command completion, it is your friend.
6636 GDB also now accepts a variety of C++ mangled symbol formats. They are
6637 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6638 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6639 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6640 for the list of formats.
6642 * G++ symbol mangling problem
6644 Recent versions of gcc have a bug in how they emit debugging information for
6645 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6646 directory) can be applied to gcc to fix the problem. Alternatively, if you
6647 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6648 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6649 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6652 * New 'maintenance' command
6654 All of the commands related to hacking GDB internals have been moved out of
6655 the main command set, and now live behind the 'maintenance' command. This
6656 can also be abbreviated as 'mt'. The following changes were made:
6658 dump-me -> maintenance dump-me
6659 info all-breakpoints -> maintenance info breakpoints
6660 printmsyms -> maintenance print msyms
6661 printobjfiles -> maintenance print objfiles
6662 printpsyms -> maintenance print psymbols
6663 printsyms -> maintenance print symbols
6665 The following commands are new:
6667 maintenance demangle Call internal GDB demangler routine to
6668 demangle a C++ link name and prints the result.
6669 maintenance print type Print a type chain for a given symbol
6671 * Change to .gdbinit file processing
6673 We now read the $HOME/.gdbinit file before processing the argv arguments
6674 (e.g. reading symbol files or core files). This allows global parameters to
6675 be set, which will apply during the symbol reading. The ./.gdbinit is still
6676 read after argv processing.
6678 * New hosts supported
6680 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6682 GNU/Linux support i386-unknown-linux or linux
6684 We are also including code to support the HP/PA running BSD and HPUX. This
6685 is almost guaranteed not to work, as we didn't have time to test or build it
6686 for this release. We are including it so that the more adventurous (or
6687 masochistic) of you can play with it. We also had major problems with the
6688 fact that the compiler that we got from HP doesn't support the -g option.
6691 * New targets supported
6693 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6695 * More smarts about finding #include files
6697 GDB now remembers the compilation directory for all include files, and for
6698 all files from which C is generated (like yacc and lex sources). This
6699 greatly improves GDB's ability to find yacc/lex sources, and include files,
6700 especially if you are debugging your program from a directory different from
6701 the one that contains your sources.
6703 We also fixed a bug which caused difficulty with listing and setting
6704 breakpoints in include files which contain C code. (In the past, you had to
6705 try twice in order to list an include file that you hadn't looked at before.)
6707 * Interesting infernals change
6709 GDB now deals with arbitrary numbers of sections, where the symbols for each
6710 section must be relocated relative to that section's landing place in the
6711 target's address space. This work was needed to support ELF with embedded
6712 stabs used by Solaris-2.0.
6714 * Bug fixes (of course!)
6716 There have been loads of fixes for the following things:
6717 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6718 i960, stabs, DOS(GO32), procfs, etc...
6720 See the ChangeLog for details.
6722 *** Changes in GDB-4.5:
6724 * New machines supported (host and target)
6726 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6728 SGI Irix-4.x mips-sgi-irix4 or iris4
6730 * New malloc package
6732 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6733 Mmalloc is capable of handling mutiple heaps of memory. It is also
6734 capable of saving a heap to a file, and then mapping it back in later.
6735 This can be used to greatly speedup the startup of GDB by using a
6736 pre-parsed symbol table which lives in a mmalloc managed heap. For
6737 more details, please read mmalloc/mmalloc.texi.
6741 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6742 'help info proc' for details.
6744 * MIPS ecoff symbol table format
6746 The code that reads MIPS symbol table format is now supported on all hosts.
6747 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6750 * File name changes for MS-DOS
6752 Many files in the config directories have been renamed to make it easier to
6753 support GDB on MS-DOSe systems (which have very restrictive file name
6754 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6755 environment) is close to working but has some remaining problems. Note
6756 that debugging of DOS programs is not supported, due to limitations
6757 in the ``operating system'', but it can be used to host cross-debugging.
6759 * Cross byte order fixes
6761 Many fixes have been made to support cross debugging of Sparc and MIPS
6762 targets from hosts whose byte order differs.
6764 * New -mapped and -readnow options
6766 If memory-mapped files are available on your system through the 'mmap'
6767 system call, you can use the -mapped option on the `file' or
6768 `symbol-file' commands to cause GDB to write the symbols from your
6769 program into a reusable file. If the program you are debugging is
6770 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6771 Future GDB debugging sessions will notice the presence of this file,
6772 and will quickly map in symbol information from it, rather than reading
6773 the symbol table from the executable program. Using the '-mapped'
6774 option in a GDB `file' or `symbol-file' command has the same effect as
6775 starting GDB with the '-mapped' command-line option.
6777 You can cause GDB to read the entire symbol table immediately by using
6778 the '-readnow' option with any of the commands that load symbol table
6779 information (or on the GDB command line). This makes the command
6780 slower, but makes future operations faster.
6782 The -mapped and -readnow options are typically combined in order to
6783 build a `fred.syms' file that contains complete symbol information.
6784 A simple GDB invocation to do nothing but build a `.syms' file for future
6787 gdb -batch -nx -mapped -readnow programname
6789 The `.syms' file is specific to the host machine on which GDB is run.
6790 It holds an exact image of GDB's internal symbol table. It cannot be
6791 shared across multiple host platforms.
6793 * longjmp() handling
6795 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6796 siglongjmp() without losing control. This feature has not yet been ported to
6797 all systems. It currently works on many 386 platforms, all MIPS-based
6798 platforms (SGI, DECstation, etc), and Sun3/4.
6802 Preliminary work has been put in to support the new Solaris OS from Sun. At
6803 this time, it can control and debug processes, but it is not capable of
6808 As always, many many bug fixes. The major areas were with g++, and mipsread.
6809 People using the MIPS-based platforms should experience fewer mysterious
6810 crashes and trashed symbol tables.
6812 *** Changes in GDB-4.4:
6814 * New machines supported (host and target)
6816 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6818 BSD Reno on Vax vax-dec-bsd
6819 Ultrix on Vax vax-dec-ultrix
6821 * New machines supported (target)
6823 AMD 29000 embedded, using EBMON a29k-none-none
6827 GDB continues to improve its handling of C++. `References' work better.
6828 The demangler has also been improved, and now deals with symbols mangled as
6829 per the Annotated C++ Reference Guide.
6831 GDB also now handles `stabs' symbol information embedded in MIPS
6832 `ecoff' symbol tables. Since the ecoff format was not easily
6833 extensible to handle new languages such as C++, this appeared to be a
6834 good way to put C++ debugging info into MIPS binaries. This option
6835 will be supported in the GNU C compiler, version 2, when it is
6838 * New features for SVR4
6840 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6841 shared libraries. Debugging dynamically linked programs should present
6842 only minor differences from debugging statically linked programs.
6844 The `info proc' command will print out information about any process
6845 on an SVR4 system (including the one you are debugging). At the moment,
6846 it prints the address mappings of the process.
6848 If you bring up GDB on another SVR4 system, please send mail to
6849 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6851 * Better dynamic linking support in SunOS
6853 Reading symbols from shared libraries which contain debugging symbols
6854 now works properly. However, there remain issues such as automatic
6855 skipping of `transfer vector' code during function calls, which
6856 make it harder to debug code in a shared library, than to debug the
6857 same code linked statically.
6861 GDB is now using the latest `getopt' routines from the FSF. This
6862 version accepts the -- prefix for options with long names. GDB will
6863 continue to accept the old forms (-option and +option) as well.
6864 Various single letter abbreviations for options have been explicity
6865 added to the option table so that they won't get overshadowed in the
6866 future by other options that begin with the same letter.
6870 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6871 Many assorted bugs have been handled. Many more remain to be handled.
6872 See the various ChangeLog files (primarily in gdb and bfd) for details.
6875 *** Changes in GDB-4.3:
6877 * New machines supported (host and target)
6879 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6880 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6881 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6883 * Almost SCO Unix support
6885 We had hoped to support:
6886 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6887 (except for core file support), but we discovered very late in the release
6888 that it has problems with process groups that render gdb unusable. Sorry
6889 about that. I encourage people to fix it and post the fixes.
6891 * Preliminary ELF and DWARF support
6893 GDB can read ELF object files on System V Release 4, and can handle
6894 debugging records for C, in DWARF format, in ELF files. This support
6895 is preliminary. If you bring up GDB on another SVR4 system, please
6896 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6901 GDB now uses the latest `readline' library. One user-visible change
6902 is that two tabs will list possible command completions, which previously
6903 required typing M-? (meta-question mark, or ESC ?).
6907 The `stepi' bug that many of you noticed has been squashed.
6908 Many bugs in C++ have been handled. Many more remain to be handled.
6909 See the various ChangeLog files (primarily in gdb and bfd) for details.
6911 * State of the MIPS world (in case you wondered):
6913 GDB can understand the symbol tables emitted by the compilers
6914 supplied by most vendors of MIPS-based machines, including DEC. These
6915 symbol tables are in a format that essentially nobody else uses.
6917 Some versions of gcc come with an assembler post-processor called
6918 mips-tfile. This program is required if you want to do source-level
6919 debugging of gcc-compiled programs. I believe FSF does not ship
6920 mips-tfile with gcc version 1, but it will eventually come with gcc
6923 Debugging of g++ output remains a problem. g++ version 1.xx does not
6924 really support it at all. (If you're lucky, you should be able to get
6925 line numbers and stack traces to work, but no parameters or local
6926 variables.) With some work it should be possible to improve the
6929 When gcc version 2 is released, you will have somewhat better luck.
6930 However, even then you will get confusing results for inheritance and
6933 We will eventually provide full debugging of g++ output on
6934 DECstations. This will probably involve some kind of stabs-in-ecoff
6935 encapulation, but the details have not been worked out yet.
6938 *** Changes in GDB-4.2:
6940 * Improved configuration
6942 Only one copy of `configure' exists now, and it is not self-modifying.
6943 Porting BFD is simpler.
6947 The `step' and `next' commands now only stop at the first instruction
6948 of a source line. This prevents the multiple stops that used to occur
6949 in switch statements, for-loops, etc. `Step' continues to stop if a
6950 function that has debugging information is called within the line.
6954 Lots of small bugs fixed. More remain.
6956 * New host supported (not target)
6958 Intel 386 PC clone running Mach i386-none-mach
6961 *** Changes in GDB-4.1:
6963 * Multiple source language support
6965 GDB now has internal scaffolding to handle several source languages.
6966 It determines the type of each source file from its filename extension,
6967 and will switch expression parsing and number formatting to match the
6968 language of the function in the currently selected stack frame.
6969 You can also specifically set the language to be used, with
6970 `set language c' or `set language modula-2'.
6974 GDB now has preliminary support for the GNU Modula-2 compiler,
6975 currently under development at the State University of New York at
6976 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6977 continue through the fall of 1991 and into 1992.
6979 Other Modula-2 compilers are currently not supported, and attempting to
6980 debug programs compiled with them will likely result in an error as the
6981 symbol table is read. Feel free to work on it, though!
6983 There are hooks in GDB for strict type checking and range checking,
6984 in the `Modula-2 philosophy', but they do not currently work.
6988 GDB can now write to executable and core files (e.g. patch
6989 a variable's value). You must turn this switch on, specify
6990 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6991 by assigning a new value to a variable. Modifications take
6994 * Automatic SunOS shared library reading
6996 When you run your program, GDB automatically determines where its
6997 shared libraries (if any) have been loaded, and reads their symbols.
6998 The `share' command is no longer needed. This also works when
6999 examining core files.
7003 You can specify the number of lines that the `list' command shows.
7006 * New machines supported (host and target)
7008 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7009 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7010 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7012 * New hosts supported (not targets)
7014 IBM RT/PC: romp-ibm-aix or rtpc
7016 * New targets supported (not hosts)
7018 AMD 29000 embedded with COFF a29k-none-coff
7019 AMD 29000 embedded with a.out a29k-none-aout
7020 Ultracomputer remote kernel debug a29k-nyu-kern
7022 * New remote interfaces
7028 *** Changes in GDB-4.0:
7032 Wide output is wrapped at good places to make the output more readable.
7034 Gdb now supports cross-debugging from a host machine of one type to a
7035 target machine of another type. Communication with the target system
7036 is over serial lines. The ``target'' command handles connecting to the
7037 remote system; the ``load'' command will download a program into the
7038 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7039 also supports debugging of realtime processes running under VxWorks,
7040 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7041 stub on the target system.
7043 New CPUs supported include the AMD 29000 and Intel 960.
7045 GDB now reads object files and symbol tables via a ``binary file''
7046 library, which allows a single copy of GDB to debug programs of multiple
7047 object file types such as a.out and coff.
7049 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7050 refcard.dvi and refcard.ps are available to format it).
7053 * Control-Variable user interface simplified
7055 All variables that control the operation of the debugger can be set
7056 by the ``set'' command, and displayed by the ``show'' command.
7058 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7059 ``Show prompt'' produces the response:
7060 Gdb's prompt is new-gdb=>.
7062 What follows are the NEW set commands. The command ``help set'' will
7063 print a complete list of old and new set commands. ``help set FOO''
7064 will give a longer description of the variable FOO. ``show'' will show
7065 all of the variable descriptions and their current settings.
7067 confirm on/off: Enables warning questions for operations that are
7068 hard to recover from, e.g. rerunning the program while
7069 it is already running. Default is ON.
7071 editing on/off: Enables EMACS style command line editing
7072 of input. Previous lines can be recalled with
7073 control-P, the current line can be edited with control-B,
7074 you can search for commands with control-R, etc.
7077 history filename NAME: NAME is where the gdb command history
7078 will be stored. The default is .gdb_history,
7079 or the value of the environment variable
7082 history size N: The size, in commands, of the command history. The
7083 default is 256, or the value of the environment variable
7086 history save on/off: If this value is set to ON, the history file will
7087 be saved after exiting gdb. If set to OFF, the
7088 file will not be saved. The default is OFF.
7090 history expansion on/off: If this value is set to ON, then csh-like
7091 history expansion will be performed on
7092 command line input. The default is OFF.
7094 radix N: Sets the default radix for input and output. It can be set
7095 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7096 in the current radix, so "set radix 10" is always a no-op.
7098 height N: This integer value is the number of lines on a page. Default
7099 is 24, the current `stty rows'' setting, or the ``li#''
7100 setting from the termcap entry matching the environment
7103 width N: This integer value is the number of characters on a line.
7104 Default is 80, the current `stty cols'' setting, or the ``co#''
7105 setting from the termcap entry matching the environment
7108 Note: ``set screensize'' is obsolete. Use ``set height'' and
7109 ``set width'' instead.
7111 print address on/off: Print memory addresses in various command displays,
7112 such as stack traces and structure values. Gdb looks
7113 more ``symbolic'' if you turn this off; it looks more
7114 ``machine level'' with it on. Default is ON.
7116 print array on/off: Prettyprint arrays. New convenient format! Default
7119 print demangle on/off: Print C++ symbols in "source" form if on,
7122 print asm-demangle on/off: Same, for assembler level printouts
7125 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7128 * Support for Epoch Environment.
7130 The epoch environment is a version of Emacs v18 with windowing. One
7131 new command, ``inspect'', is identical to ``print'', except that if you
7132 are running in the epoch environment, the value is printed in its own
7136 * Support for Shared Libraries
7138 GDB can now debug programs and core files that use SunOS shared libraries.
7139 Symbols from a shared library cannot be referenced
7140 before the shared library has been linked with the program (this
7141 happens after you type ``run'' and before the function main() is entered).
7142 At any time after this linking (including when examining core files
7143 from dynamically linked programs), gdb reads the symbols from each
7144 shared library when you type the ``sharedlibrary'' command.
7145 It can be abbreviated ``share''.
7147 sharedlibrary REGEXP: Load shared object library symbols for files
7148 matching a unix regular expression. No argument
7149 indicates to load symbols for all shared libraries.
7151 info sharedlibrary: Status of loaded shared libraries.
7156 A watchpoint stops execution of a program whenever the value of an
7157 expression changes. Checking for this slows down execution
7158 tremendously whenever you are in the scope of the expression, but is
7159 quite useful for catching tough ``bit-spreader'' or pointer misuse
7160 problems. Some machines such as the 386 have hardware for doing this
7161 more quickly, and future versions of gdb will use this hardware.
7163 watch EXP: Set a watchpoint (breakpoint) for an expression.
7165 info watchpoints: Information about your watchpoints.
7167 delete N: Deletes watchpoint number N (same as breakpoints).
7168 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7169 enable N: Re-enables watchpoint number N (same as breakpoints).
7172 * C++ multiple inheritance
7174 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7177 * C++ exception handling
7179 Gdb now supports limited C++ exception handling. Besides the existing
7180 ability to breakpoint on an exception handler, gdb can breakpoint on
7181 the raising of an exception (before the stack is peeled back to the
7184 catch FOO: If there is a FOO exception handler in the dynamic scope,
7185 set a breakpoint to catch exceptions which may be raised there.
7186 Multiple exceptions (``catch foo bar baz'') may be caught.
7188 info catch: Lists all exceptions which may be caught in the
7189 current stack frame.
7192 * Minor command changes
7194 The command ``call func (arg, arg, ...)'' now acts like the print
7195 command, except it does not print or save a value if the function's result
7196 is void. This is similar to dbx usage.
7198 The ``up'' and ``down'' commands now always print the frame they end up
7199 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7200 frames without printing.
7202 * New directory command
7204 'dir' now adds directories to the FRONT of the source search path.
7205 The path starts off empty. Source files that contain debug information
7206 about the directory in which they were compiled can be found even
7207 with an empty path; Sun CC and GCC include this information. If GDB can't
7208 find your source file in the current directory, type "dir .".
7210 * Configuring GDB for compilation
7212 For normal use, type ``./configure host''. See README or gdb.texinfo
7215 GDB now handles cross debugging. If you are remotely debugging between
7216 two different machines, type ``./configure host -target=targ''.
7217 Host is the machine where GDB will run; targ is the machine
7218 where the program that you are debugging will run.