1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB now has experimental support for the compilation and injection of
7 C++ source code into the inferior. This beta release does not include
8 support for several language features, such as templates, constructors,
11 This feature requires GCC 7.1 or higher built with libcp1.so
14 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
15 can be passed using the '[ADDRESS]:PORT' notation, or the regular
16 'ADDRESS:PORT' method.
18 * DWARF index cache: GDB can now automatically save indices of DWARF
19 symbols on disk to speed up further loading of the same binaries.
21 * GDB in batch mode now exits with status 1 if the last command to be
24 * Changes to the "frame", "select-frame", and "info frame" CLI
25 commands. These commands all now take a frame specification which
26 is either a frame level, or one of the keywords 'level', 'address',
27 'function', or 'view' followed by a parameter. Selecting a frame by
28 address, or viewing a frame outside the current backtrace now
29 requires the use of a keyword. Selecting a frame by level is
30 unchanged. The MI comment "-stack-select-frame" is unchanged.
34 set debug compile-cplus-types
35 show debug compile-cplus-types
36 Control the display of debug output about type conversion in the
37 C++ compile feature. Commands have no effect while compiliong
42 Control whether debug output about files/functions skipping is
45 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
46 Apply a command to some frames.
47 FLAG arguments allow to control what output to produce and how to handle
48 errors raised when applying COMMAND to a frame.
51 Apply a command to all threads (ignoring errors and empty output).
52 Shortcut for 'thread apply all -s COMMAND'.
55 Apply a command to all frames (ignoring errors and empty output).
56 Shortcut for 'frame apply all -s COMMAND'.
59 Apply a command to all frames of all threads (ignoring errors and empty
61 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
63 maint set dwarf unwinders (on|off)
64 maint show dwarf unwinders
65 Control whether DWARF unwinders can be used.
68 Display a list of open files for a process.
72 target remote FILENAME
73 target extended-remote FILENAME
74 If FILENAME is a Unix domain socket, GDB will attempt to connect
75 to this socket instead of opening FILENAME as a character device.
77 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
78 The 'thread apply' command accepts new FLAG arguments.
79 FLAG arguments allow to control what output to produce and how to handle
80 errors raised when applying COMMAND to a thread.
84 ** The '-data-disassemble' MI command now accepts an '-a' option to
85 disassemble the whole function surrounding the given program
86 counter value or function name. Support for this feature can be
87 verified by using the "-list-features" command, which should
88 contain "data-disassemble-a-option".
90 ** Command responses and notifications that include a frame now include
91 the frame's architecture in a new "arch" attribute.
93 * New native configurations
95 GNU/Linux/RISC-V riscv*-*-linux*
96 FreeBSD/riscv riscv*-*-freebsd*
100 GNU/Linux/RISC-V riscv*-*-linux*
102 CSKY GNU/LINUX csky*-*-linux
103 FreeBSD/riscv riscv*-*-freebsd*
107 ** The gdb.Inferior type has a new 'progspace' property, which is the program
108 space associated to that inferior.
110 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
111 of objfiles associated to that program space.
113 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
114 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
117 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
118 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
119 correct and did not work properly.
125 Enable or disable the undefined behavior sanitizer. Release
126 versions of GDB disable this by default if it is available, but
127 development versions enable it. Enabling this can cause a
128 performance penalty. The undefined behavior sanitizer was first
129 introduced in GCC 4.9.
131 *** Changes in GDB 8.2
133 * The 'set disassembler-options' command now supports specifying options
136 * The 'symbol-file' command now accepts an '-o' option to add a relative
137 offset to all sections.
139 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
140 a relative offset to all sections, but it allows to override the load
141 address of individual sections using '-s'.
143 * The 'add-symbol-file' command no longer requires the second argument
144 (address of the text section).
146 * The endianness used with the 'set endian auto' mode in the absence of
147 an executable selected for debugging is now the last endianness chosen
148 either by one of the 'set endian big' and 'set endian little' commands
149 or by inferring from the last executable used, rather than the startup
152 * The pager now allows a "c" response, meaning to disable the pager
153 for the rest of the current command.
155 * The commands 'info variables/functions/types' now show the source line
156 numbers of symbol definitions when available.
158 * 'info proc' now works on running processes on FreeBSD systems and core
159 files created on FreeBSD systems.
161 * C expressions can now use _Alignof, and C++ expressions can now use
164 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
165 the vector length while the process is running.
171 Control display of debugging info regarding the FreeBSD native target.
173 set|show varsize-limit
174 This new setting allows the user to control the maximum size of Ada
175 objects being printed when those objects have a variable type,
176 instead of that maximum size being hardcoded to 65536 bytes.
178 set|show record btrace cpu
179 Controls the processor to be used for enabling errata workarounds for
182 maint check libthread-db
183 Run integrity checks on the current inferior's thread debugging
186 maint set check-libthread-db (on|off)
187 maint show check-libthread-db
188 Control whether to run integrity checks on inferior specific thread
189 debugging libraries as they are loaded. The default is not to
194 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
196 ** The commands attached to a breakpoint can be set by assigning to
197 the breakpoint's "commands" field.
199 ** gdb.execute can now execute multi-line gdb commands.
201 ** The new functions gdb.convenience_variable and
202 gdb.set_convenience_variable can be used to get and set the value
203 of convenience variables.
205 ** A gdb.Parameter will no longer print the "set" help text on an
206 ordinary "set"; instead by default a "set" will be silent unless
207 the get_set_string method returns a non-empty string.
211 RiscV ELF riscv*-*-elf
213 * Removed targets and native configurations
215 m88k running OpenBSD m88*-*-openbsd*
216 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
217 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
218 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
220 * Aarch64/Linux hardware watchpoints improvements
222 Hardware watchpoints on unaligned addresses are now properly
223 supported when running Linux kernel 4.10 or higher: read and access
224 watchpoints are no longer spuriously missed, and all watchpoints
225 lengths between 1 and 8 bytes are supported. On older kernels,
226 watchpoints set on unaligned addresses are no longer missed, with
227 the tradeoff that there is a possibility of false hits being
232 --enable-codesign=CERT
233 This can be used to invoke "codesign -s CERT" after building gdb.
234 This option is useful on macOS, where code signing is required for
235 gdb to work properly.
237 --disable-gdbcli has been removed
238 This is now silently accepted, but does nothing.
240 *** Changes in GDB 8.1
242 * GDB now supports dynamically creating arbitrary register groups specified
243 in XML target descriptions. This allows for finer grain grouping of
244 registers on systems with a large amount of registers.
246 * The 'ptype' command now accepts a '/o' flag, which prints the
247 offsets and sizes of fields in a struct, like the pahole(1) tool.
249 * New "--readnever" command line option instructs GDB to not read each
250 symbol file's symbolic debug information. This makes startup faster
251 but at the expense of not being able to perform symbolic debugging.
252 This option is intended for use cases where symbolic debugging will
253 not be used, e.g., when you only need to dump the debuggee's core.
255 * GDB now uses the GNU MPFR library, if available, to emulate target
256 floating-point arithmetic during expression evaluation when the target
257 uses different floating-point formats than the host. At least version
258 3.1 of GNU MPFR is required.
260 * GDB now supports access to the guarded-storage-control registers and the
261 software-based guarded-storage broadcast control registers on IBM z14.
263 * On Unix systems, GDB now supports transmitting environment variables
264 that are to be set or unset to GDBserver. These variables will
265 affect the environment to be passed to the remote inferior.
267 To inform GDB of environment variables that are to be transmitted to
268 GDBserver, use the "set environment" command. Only user set
269 environment variables are sent to GDBserver.
271 To inform GDB of environment variables that are to be unset before
272 the remote inferior is started by the GDBserver, use the "unset
273 environment" command.
275 * Completion improvements
277 ** GDB can now complete function parameters in linespecs and
278 explicit locations without quoting. When setting breakpoints,
279 quoting around functions names to help with TAB-completion is
280 generally no longer necessary. For example, this now completes
283 (gdb) b function(in[TAB]
284 (gdb) b function(int)
286 Related, GDB is no longer confused with completing functions in
287 C++ anonymous namespaces:
290 (gdb) b (anonymous namespace)::[TAB][TAB]
291 (anonymous namespace)::a_function()
292 (anonymous namespace)::b_function()
294 ** GDB now has much improved linespec and explicit locations TAB
295 completion support, that better understands what you're
296 completing and offers better suggestions. For example, GDB no
297 longer offers data symbols as possible completions when you're
298 setting a breakpoint.
300 ** GDB now TAB-completes label symbol names.
302 ** The "complete" command now mimics TAB completion accurately.
304 * New command line options (gcore)
307 Dump all memory mappings.
309 * Breakpoints on C++ functions are now set on all scopes by default
311 By default, breakpoints on functions/methods are now interpreted as
312 specifying all functions with the given name ignoring missing
313 leading scopes (namespaces and classes).
315 For example, assuming a C++ program with symbols named:
320 both commands "break func()" and "break B::func()" set a breakpoint
323 You can use the new flag "-qualified" to override this. This makes
324 GDB interpret the specified function name as a complete
325 fully-qualified name instead. For example, using the same C++
326 program, the "break -q B::func" command sets a breakpoint on
327 "B::func", only. A parameter has been added to the Python
328 gdb.Breakpoint constructor to achieve the same result when creating
329 a breakpoint from Python.
331 * Breakpoints on functions marked with C++ ABI tags
333 GDB can now set breakpoints on functions marked with C++ ABI tags
334 (e.g., [abi:cxx11]). See here for a description of ABI tags:
335 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
337 Functions with a C++11 abi tag are demangled/displayed like this:
339 function[abi:cxx11](int)
342 You can now set a breakpoint on such functions simply as if they had
345 (gdb) b function(int)
347 Or if you need to disambiguate between tags, like:
349 (gdb) b function[abi:other_tag](int)
351 Tab completion was adjusted accordingly as well.
355 ** New events gdb.new_inferior, gdb.inferior_deleted, and
356 gdb.new_thread are emitted. See the manual for further
357 description of these.
359 ** A new function, "gdb.rbreak" has been added to the Python API.
360 This function allows the setting of a large number of breakpoints
361 via a regex pattern in Python. See the manual for further details.
363 ** Python breakpoints can now accept explicit locations. See the
364 manual for a further description of this feature.
367 * New features in the GDB remote stub, GDBserver
369 ** GDBserver is now able to start inferior processes with a
370 specified initial working directory.
372 The user can set the desired working directory to be used from
373 GDB using the new "set cwd" command.
375 ** New "--selftest" command line option runs some GDBserver self
376 tests. These self tests are disabled in releases.
378 ** On Unix systems, GDBserver now does globbing expansion and variable
379 substitution in inferior command line arguments.
381 This is done by starting inferiors using a shell, like GDB does.
382 See "set startup-with-shell" in the user manual for how to disable
383 this from GDB when using "target extended-remote". When using
384 "target remote", you can disable the startup with shell by using the
385 new "--no-startup-with-shell" GDBserver command line option.
387 ** On Unix systems, GDBserver now supports receiving environment
388 variables that are to be set or unset from GDB. These variables
389 will affect the environment to be passed to the inferior.
391 * When catching an Ada exception raised with a message, GDB now prints
392 the message in the catchpoint hit notification. In GDB/MI mode, that
393 information is provided as an extra field named "exception-message"
394 in the *stopped notification.
396 * Trait objects can now be inspected When debugging Rust code. This
397 requires compiler support which will appear in Rust 1.24.
401 QEnvironmentHexEncoded
402 Inform GDBserver of an environment variable that is to be passed to
403 the inferior when starting it.
406 Inform GDBserver of an environment variable that is to be unset
407 before starting the remote inferior.
410 Inform GDBserver that the environment should be reset (i.e.,
411 user-set environment variables should be unset).
414 Indicates whether the inferior must be started with a shell or not.
417 Tell GDBserver that the inferior to be started should use a specific
420 * The "maintenance print c-tdesc" command now takes an optional
421 argument which is the file name of XML target description.
423 * The "maintenance selftest" command now takes an optional argument to
424 filter the tests to be run.
426 * The "enable", and "disable" commands now accept a range of
427 breakpoint locations, e.g. "enable 1.3-5".
432 Set and show the current working directory for the inferior.
435 Set and show compilation command used for compiling and injecting code
436 with the 'compile' commands.
438 set debug separate-debug-file
439 show debug separate-debug-file
440 Control the display of debug output about separate debug file search.
442 set dump-excluded-mappings
443 show dump-excluded-mappings
444 Control whether mappings marked with the VM_DONTDUMP flag should be
445 dumped when generating a core file.
448 List the registered selftests.
451 Start the debugged program stopping at the first instruction.
454 Control display of debugging messages related to OpenRISC targets.
456 set|show print type nested-type-limit
457 Set and show the limit of nesting level for nested types that the
458 type printer will show.
460 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
463 * Safer/improved support for debugging with no debug info
465 GDB no longer assumes functions with no debug information return
468 This means that GDB now refuses to call such functions unless you
469 tell it the function's type, by either casting the call to the
470 declared return type, or by casting the function to a function
471 pointer of the right type, and calling that:
473 (gdb) p getenv ("PATH")
474 'getenv' has unknown return type; cast the call to its declared return type
475 (gdb) p (char *) getenv ("PATH")
476 $1 = 0x7fffffffe "/usr/local/bin:/"...
477 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
478 $2 = 0x7fffffffe "/usr/local/bin:/"...
480 Similarly, GDB no longer assumes that global variables with no debug
481 info have type 'int', and refuses to print the variable's value
482 unless you tell it the variable's type:
485 'var' has unknown type; cast it to its declared type
489 * New native configurations
491 FreeBSD/aarch64 aarch64*-*-freebsd*
492 FreeBSD/arm arm*-*-freebsd*
496 FreeBSD/aarch64 aarch64*-*-freebsd*
497 FreeBSD/arm arm*-*-freebsd*
498 OpenRISC ELF or1k*-*-elf
500 * Removed targets and native configurations
502 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
504 *** Changes in GDB 8.0
506 * GDB now supports access to the PKU register on GNU/Linux. The register is
507 added by the Memory Protection Keys for Userspace feature which will be
508 available in future Intel CPUs.
510 * GDB now supports C++11 rvalue references.
514 ** New functions to start, stop and access a running btrace recording.
515 ** Rvalue references are now supported in gdb.Type.
517 * GDB now supports recording and replaying rdrand and rdseed Intel 64
520 * Building GDB and GDBserver now requires a C++11 compiler.
522 For example, GCC 4.8 or later.
524 It is no longer possible to build GDB or GDBserver with a C
525 compiler. The --disable-build-with-cxx configure option has been
528 * Building GDB and GDBserver now requires GNU make >= 3.81.
530 It is no longer supported to build GDB or GDBserver with another
531 implementation of the make program or an earlier version of GNU make.
533 * Native debugging on MS-Windows supports command-line redirection
535 Command-line arguments used for starting programs on MS-Windows can
536 now include redirection symbols supported by native Windows shells,
537 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
538 as "run", "start", and "set args", as well as the corresponding MI
541 * Support for thread names on MS-Windows.
543 GDB now catches and handles the special exception that programs
544 running on MS-Windows use to assign names to threads in the
547 * Support for Java programs compiled with gcj has been removed.
549 * User commands now accept an unlimited number of arguments.
550 Previously, only up to 10 was accepted.
552 * The "eval" command now expands user-defined command arguments.
554 This makes it easier to process a variable number of arguments:
559 eval "print $arg%d", $i
564 * Target descriptions can now describe registers for sparc32 and sparc64.
566 * GDB now supports DWARF version 5 (debug information format).
567 Its .debug_names index is not yet supported.
569 * New native configurations
571 FreeBSD/mips mips*-*-freebsd
575 Synopsys ARC arc*-*-elf32
576 FreeBSD/mips mips*-*-freebsd
578 * Removed targets and native configurations
580 Alpha running FreeBSD alpha*-*-freebsd*
581 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
586 Erases all the flash memory regions reported by the target.
588 maint print arc arc-instruction address
589 Print internal disassembler information about instruction at a given address.
593 set disassembler-options
594 show disassembler-options
595 Controls the passing of target specific information to the disassembler.
596 If it is necessary to specify more than one disassembler option then
597 multiple options can be placed together into a comma separated list.
598 The default value is the empty string. Currently, the only supported
599 targets are ARM, PowerPC and S/390.
604 Erases all the flash memory regions reported by the target. This is
605 equivalent to the CLI command flash-erase.
607 -file-list-shared-libraries
608 List the shared libraries in the program. This is
609 equivalent to the CLI command "info shared".
612 Catchpoints stopping the program when Ada exceptions are
613 handled. This is equivalent to the CLI command "catch handlers".
615 *** Changes in GDB 7.12
617 * GDB and GDBserver now build with a C++ compiler by default.
619 The --enable-build-with-cxx configure option is now enabled by
620 default. One must now explicitly configure with
621 --disable-build-with-cxx in order to build with a C compiler. This
622 option will be removed in a future release.
624 * GDBserver now supports recording btrace without maintaining an active
627 * GDB now supports a negative repeat count in the 'x' command to examine
628 memory backward from the given address. For example:
631 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
632 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
633 (gdb) x/-5i 0x0000000000400580
634 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
635 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
636 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
637 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
638 0x40057b <main(int, char**)+25>:
639 callq 0x400536 <Func1(int, char const*)>
641 * Fortran: Support structures with fields of dynamic types and
642 arrays of dynamic types.
644 * The symbol dumping maintenance commands have new syntax.
645 maint print symbols [-pc address] [--] [filename]
646 maint print symbols [-objfile objfile] [-source source] [--] [filename]
647 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
648 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
649 maint print msymbols [-objfile objfile] [--] [filename]
651 * GDB now supports multibit bitfields and enums in target register
654 * New Python-based convenience function $_as_string(val), which returns
655 the textual representation of a value. This function is especially
656 useful to obtain the text label of an enum value.
658 * Intel MPX bound violation handling.
660 Segmentation faults caused by a Intel MPX boundary violation
661 now display the kind of violation (upper or lower), the memory
662 address accessed and the memory bounds, along with the usual
663 signal received and code location.
667 Program received signal SIGSEGV, Segmentation fault
668 Upper bound violation while accessing address 0x7fffffffc3b3
669 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
670 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
672 * Rust language support.
673 GDB now supports debugging programs written in the Rust programming
674 language. See https://www.rust-lang.org/ for more information about
677 * Support for running interpreters on specified input/output devices
679 GDB now supports a new mechanism that allows frontends to provide
680 fully featured GDB console views, as a better alternative to
681 building such views on top of the "-interpreter-exec console"
682 command. See the new "new-ui" command below. With that command,
683 frontends can now start GDB in the traditional command-line mode
684 running in an embedded terminal emulator widget, and create a
685 separate MI interpreter running on a specified i/o device. In this
686 way, GDB handles line editing, history, tab completion, etc. in the
687 console all by itself, and the GUI uses the separate MI interpreter
688 for its own control and synchronization, invisible to the command
691 * The "catch syscall" command catches groups of related syscalls.
693 The "catch syscall" command now supports catching a group of related
694 syscalls using the 'group:' or 'g:' prefix.
699 skip -gfile file-glob-pattern
700 skip -function function
701 skip -rfunction regular-expression
702 A generalized form of the skip command, with new support for
703 glob-style file names and regular expressions for function names.
704 Additionally, a file spec and a function spec may now be combined.
706 maint info line-table REGEXP
707 Display the contents of GDB's internal line table data struture.
710 Run any GDB unit tests that were compiled in.
713 Start a new user interface instance running INTERP as interpreter,
714 using the TTY file for input/output.
718 ** gdb.Breakpoint objects have a new attribute "pending", which
719 indicates whether the breakpoint is pending.
720 ** Three new breakpoint-related events have been added:
721 gdb.breakpoint_created, gdb.breakpoint_modified, and
722 gdb.breakpoint_deleted.
725 Signal ("set") the given MS-Windows event object. This is used in
726 conjunction with the Windows JIT debugging (AeDebug) support, where
727 the OS suspends a crashing process until a debugger can attach to
728 it. Resuming the crashing process, in order to debug it, is done by
731 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
732 was added in GDBserver, including JIT compiling fast tracepoint's
733 conditional expression bytecode into native code.
735 * Support for various remote target protocols and ROM monitors has
738 target m32rsdi Remote M32R debugging over SDI
739 target mips MIPS remote debugging protocol
740 target pmon PMON ROM monitor
741 target ddb NEC's DDB variant of PMON for Vr4300
742 target rockhopper NEC RockHopper variant of PMON
743 target lsi LSI variant of PMO
745 * Support for tracepoints and fast tracepoints on powerpc-linux,
746 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
747 including JIT compiling fast tracepoint's conditional expression
748 bytecode into native code.
750 * MI async record =record-started now includes the method and format used for
751 recording. For example:
753 =record-started,thread-group="i1",method="btrace",format="bts"
755 * MI async record =thread-selected now includes the frame field. For example:
757 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
761 Andes NDS32 nds32*-*-elf
763 *** Changes in GDB 7.11
765 * GDB now supports debugging kernel-based threads on FreeBSD.
767 * Per-inferior thread numbers
769 Thread numbers are now per inferior instead of global. If you're
770 debugging multiple inferiors, GDB displays thread IDs using a
771 qualified INF_NUM.THR_NUM form. For example:
775 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
776 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
777 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
778 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
780 As consequence, thread numbers as visible in the $_thread
781 convenience variable and in Python's InferiorThread.num attribute
782 are no longer unique between inferiors.
784 GDB now maintains a second thread ID per thread, referred to as the
785 global thread ID, which is the new equivalent of thread numbers in
786 previous releases. See also $_gthread below.
788 For backwards compatibility, MI's thread IDs always refer to global
791 * Commands that accept thread IDs now accept the qualified
792 INF_NUM.THR_NUM form as well. For example:
795 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
798 * In commands that accept a list of thread IDs, you can now refer to
799 all threads of an inferior using a star wildcard. GDB accepts
800 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
801 refer to all threads of the current inferior. For example, "info
804 * You can use "info threads -gid" to display the global thread ID of
807 * The new convenience variable $_gthread holds the global number of
810 * The new convenience variable $_inferior holds the number of the
813 * GDB now displays the ID and name of the thread that hit a breakpoint
814 or received a signal, if your program is multi-threaded. For
817 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
818 Thread 1 "main" received signal SIGINT, Interrupt.
820 * Record btrace now supports non-stop mode.
822 * Support for tracepoints on aarch64-linux was added in GDBserver.
824 * The 'record instruction-history' command now indicates speculative execution
825 when using the Intel Processor Trace recording format.
827 * GDB now allows users to specify explicit locations, bypassing
828 the linespec parser. This feature is also available to GDB/MI
831 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
832 GDB now is able to debug both AArch64 applications and ARM applications
835 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
836 including JIT compiling fast tracepoint's conditional expression bytecode
839 * GDB now supports displaced stepping on AArch64 GNU/Linux.
841 * "info threads", "info inferiors", "info display", "info checkpoints"
842 and "maint info program-spaces" now list the corresponding items in
843 ascending ID order, for consistency with all other "info" commands.
845 * In Ada, the overloads selection menu has been enhanced to display the
846 parameter types and the return types for the matching overloaded subprograms.
850 maint set target-non-stop (on|off|auto)
851 maint show target-non-stop
852 Control whether GDB targets always operate in non-stop mode even if
853 "set non-stop" is "off". The default is "auto", meaning non-stop
854 mode is enabled if supported by the target.
856 maint set bfd-sharing
857 maint show bfd-sharing
858 Control the reuse of bfd objects.
862 Control display of debugging info regarding bfd caching.
866 Control display of debugging info regarding FreeBSD threads.
868 set remote multiprocess-extensions-packet
869 show remote multiprocess-extensions-packet
870 Set/show the use of the remote protocol multiprocess extensions.
872 set remote thread-events
873 show remote thread-events
874 Set/show the use of thread create/exit events.
876 set ada print-signatures on|off
877 show ada print-signatures"
878 Control whether parameter types and return types are displayed in overloads
879 selection menus. It is activaled (@code{on}) by default.
883 Controls the maximum size of memory, in bytes, that GDB will
884 allocate for value contents. Prevents incorrect programs from
885 causing GDB to allocate overly large buffers. Default is 64k.
887 * The "disassemble" command accepts a new modifier: /s.
888 It prints mixed source+disassembly like /m with two differences:
889 - disassembled instructions are now printed in program order, and
890 - and source for all relevant files is now printed.
891 The "/m" option is now considered deprecated: its "source-centric"
892 output hasn't proved useful in practice.
894 * The "record instruction-history" command accepts a new modifier: /s.
895 It behaves exactly like /m and prints mixed source+disassembly.
897 * The "set scheduler-locking" command supports a new mode "replay".
898 It behaves like "off" in record mode and like "on" in replay mode.
900 * Support for various ROM monitors has been removed:
902 target dbug dBUG ROM monitor for Motorola ColdFire
903 target picobug Motorola picobug monitor
904 target dink32 DINK32 ROM monitor for PowerPC
905 target m32r Renesas M32R/D ROM monitor
906 target mon2000 mon2000 ROM monitor
907 target ppcbug PPCBUG ROM monitor for PowerPC
909 * Support for reading/writing memory and extracting values on architectures
910 whose memory is addressable in units of any integral multiple of 8 bits.
913 Allows to break when an Ada exception is handled.
918 Indicates that an exec system call was executed.
920 exec-events feature in qSupported
921 The qSupported packet allows GDB to request support for exec
922 events using the new 'gdbfeature' exec-event, and the qSupported
923 response can contain the corresponding 'stubfeature'. Set and
924 show commands can be used to display whether these features are enabled.
927 Equivalent to interrupting with the ^C character, but works in
930 thread created stop reason (T05 create:...)
931 Indicates that the thread was just created and is stopped at entry.
933 thread exit stop reply (w exitcode;tid)
934 Indicates that the thread has terminated.
937 Enables/disables thread create and exit event reporting. For
938 example, this is used in non-stop mode when GDB stops a set of
939 threads and synchronously waits for the their corresponding stop
940 replies. Without exit events, if one of the threads exits, GDB
941 would hang forever not knowing that it should no longer expect a
942 stop for that same thread.
945 Indicates that there are no resumed threads left in the target (all
946 threads are stopped). The remote stub reports support for this stop
947 reply to GDB's qSupported query.
950 Enables/disables catching syscalls from the inferior process.
951 The remote stub reports support for this packet to GDB's qSupported query.
953 syscall_entry stop reason
954 Indicates that a syscall was just called.
956 syscall_return stop reason
957 Indicates that a syscall just returned.
959 * Extended-remote exec events
961 ** GDB now has support for exec events on extended-remote Linux targets.
962 For such targets with Linux kernels 2.5.46 and later, this enables
963 follow-exec-mode and exec catchpoints.
965 set remote exec-event-feature-packet
966 show remote exec-event-feature-packet
967 Set/show the use of the remote exec event feature.
969 * Thread names in remote protocol
971 The reply to qXfer:threads:read may now include a name attribute for each
974 * Target remote mode fork and exec events
976 ** GDB now has support for fork and exec events on target remote mode
977 Linux targets. For such targets with Linux kernels 2.5.46 and later,
978 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
979 fork and exec catchpoints.
981 * Remote syscall events
983 ** GDB now has support for catch syscall on remote Linux targets,
984 currently enabled on x86/x86_64 architectures.
986 set remote catch-syscall-packet
987 show remote catch-syscall-packet
988 Set/show the use of the remote catch syscall feature.
992 ** The -var-set-format command now accepts the zero-hexadecimal
993 format. It outputs data in hexadecimal format with zero-padding on the
998 ** gdb.InferiorThread objects have a new attribute "global_num",
999 which refers to the thread's global thread ID. The existing
1000 "num" attribute now refers to the thread's per-inferior number.
1001 See "Per-inferior thread numbers" above.
1002 ** gdb.InferiorThread objects have a new attribute "inferior", which
1003 is the Inferior object the thread belongs to.
1005 *** Changes in GDB 7.10
1007 * Support for process record-replay and reverse debugging on aarch64*-linux*
1008 targets has been added. GDB now supports recording of A64 instruction set
1009 including advance SIMD instructions.
1011 * Support for Sun's version of the "stabs" debug file format has been removed.
1013 * GDB now honors the content of the file /proc/PID/coredump_filter
1014 (PID is the process ID) on GNU/Linux systems. This file can be used
1015 to specify the types of memory mappings that will be included in a
1016 corefile. For more information, please refer to the manual page of
1017 "core(5)". GDB also has a new command: "set use-coredump-filter
1018 on|off". It allows to set whether GDB will read the content of the
1019 /proc/PID/coredump_filter file when generating a corefile.
1021 * The "info os" command on GNU/Linux can now display information on
1023 "info os cpus" Listing of all cpus/cores on the system
1025 * GDB has two new commands: "set serial parity odd|even|none" and
1026 "show serial parity". These allows to set or show parity for the
1029 * The "info source" command now displays the producer string if it was
1030 present in the debug info. This typically includes the compiler version
1031 and may include things like its command line arguments.
1033 * The "info dll", an alias of the "info sharedlibrary" command,
1034 is now available on all platforms.
1036 * Directory names supplied to the "set sysroot" commands may be
1037 prefixed with "target:" to tell GDB to access shared libraries from
1038 the target system, be it local or remote. This replaces the prefix
1039 "remote:". The default sysroot has been changed from "" to
1040 "target:". "remote:" is automatically converted to "target:" for
1041 backward compatibility.
1043 * The system root specified by "set sysroot" will be prepended to the
1044 filename of the main executable (if reported to GDB as absolute by
1045 the operating system) when starting processes remotely, and when
1046 attaching to already-running local or remote processes.
1048 * GDB now supports automatic location and retrieval of executable
1049 files from remote targets. Remote debugging can now be initiated
1050 using only a "target remote" or "target extended-remote" command
1051 (no "set sysroot" or "file" commands are required). See "New remote
1054 * The "dump" command now supports verilog hex format.
1056 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1058 * On GNU/Linux, GDB and gdbserver are now able to access executable
1059 and shared library files without a "set sysroot" command when
1060 attaching to processes running in different mount namespaces from
1061 the debugger. This makes it possible to attach to processes in
1062 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1063 See "New remote packets" below.
1065 * The "tui reg" command now provides completion for all of the
1066 available register groups, including target specific groups.
1068 * The HISTSIZE environment variable is no longer read when determining
1069 the size of GDB's command history. GDB now instead reads the dedicated
1070 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1071 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1076 ** Memory ports can now be unbuffered.
1080 ** gdb.Objfile objects have a new attribute "username",
1081 which is the name of the objfile as specified by the user,
1082 without, for example, resolving symlinks.
1083 ** You can now write frame unwinders in Python.
1084 ** gdb.Type objects have a new method "optimized_out",
1085 returning optimized out gdb.Value instance of this type.
1086 ** gdb.Value objects have new methods "reference_value" and
1087 "const_value" which return a reference to the value and a
1088 "const" version of the value respectively.
1092 maint print symbol-cache
1093 Print the contents of the symbol cache.
1095 maint print symbol-cache-statistics
1096 Print statistics of symbol cache usage.
1098 maint flush-symbol-cache
1099 Flush the contents of the symbol cache.
1103 Start branch trace recording using Branch Trace Store (BTS) format.
1106 Evaluate expression by using the compiler and print result.
1110 Explicit commands for enabling and disabling tui mode.
1113 set mpx bound on i386 and amd64
1114 Support for bound table investigation on Intel MPX enabled applications.
1118 Start branch trace recording using Intel Processor Trace format.
1121 Print information about branch tracing internals.
1123 maint btrace packet-history
1124 Print the raw branch tracing data.
1126 maint btrace clear-packet-history
1127 Discard the stored raw branch tracing data.
1130 Discard all branch tracing data. It will be fetched and processed
1131 anew by the next "record" command.
1136 Renamed from "set debug dwarf2-die".
1137 show debug dwarf-die
1138 Renamed from "show debug dwarf2-die".
1140 set debug dwarf-read
1141 Renamed from "set debug dwarf2-read".
1142 show debug dwarf-read
1143 Renamed from "show debug dwarf2-read".
1145 maint set dwarf always-disassemble
1146 Renamed from "maint set dwarf2 always-disassemble".
1147 maint show dwarf always-disassemble
1148 Renamed from "maint show dwarf2 always-disassemble".
1150 maint set dwarf max-cache-age
1151 Renamed from "maint set dwarf2 max-cache-age".
1152 maint show dwarf max-cache-age
1153 Renamed from "maint show dwarf2 max-cache-age".
1155 set debug dwarf-line
1156 show debug dwarf-line
1157 Control display of debugging info regarding DWARF line processing.
1160 show max-completions
1161 Set the maximum number of candidates to be considered during
1162 completion. The default value is 200. This limit allows GDB
1163 to avoid generating large completion lists, the computation of
1164 which can cause the debugger to become temporarily unresponsive.
1166 set history remove-duplicates
1167 show history remove-duplicates
1168 Control the removal of duplicate history entries.
1170 maint set symbol-cache-size
1171 maint show symbol-cache-size
1172 Control the size of the symbol cache.
1174 set|show record btrace bts buffer-size
1175 Set and show the size of the ring buffer used for branch tracing in
1177 The obtained size may differ from the requested size. Use "info
1178 record" to see the obtained buffer size.
1180 set debug linux-namespaces
1181 show debug linux-namespaces
1182 Control display of debugging info regarding Linux namespaces.
1184 set|show record btrace pt buffer-size
1185 Set and show the size of the ring buffer used for branch tracing in
1186 Intel Processor Trace format.
1187 The obtained size may differ from the requested size. Use "info
1188 record" to see the obtained buffer size.
1190 maint set|show btrace pt skip-pad
1191 Set and show whether PAD packets are skipped when computing the
1194 * The command 'thread apply all' can now support new option '-ascending'
1195 to call its specified command for all threads in ascending order.
1197 * Python/Guile scripting
1199 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1200 special section named `.debug_gdb_scripts'.
1202 * New remote packets
1204 qXfer:btrace-conf:read
1205 Return the branch trace configuration for the current thread.
1207 Qbtrace-conf:bts:size
1208 Set the requested ring buffer size for branch tracing in BTS format.
1211 Enable Intel Procesor Trace-based branch tracing for the current
1212 process. The remote stub reports support for this packet to GDB's
1215 Qbtrace-conf:pt:size
1216 Set the requested ring buffer size for branch tracing in Intel Processor
1220 Indicates a memory breakpoint instruction was executed, irrespective
1221 of whether it was GDB that planted the breakpoint or the breakpoint
1222 is hardcoded in the program. This is required for correct non-stop
1226 Indicates the target stopped for a hardware breakpoint. This is
1227 required for correct non-stop mode operation.
1230 Return information about files on the remote system.
1232 qXfer:exec-file:read
1233 Return the full absolute name of the file that was executed to
1234 create a process running on the remote system.
1237 Select the filesystem on which vFile: operations with filename
1238 arguments will operate. This is required for GDB to be able to
1239 access files on remote targets where the remote stub does not
1240 share a common filesystem with the inferior(s).
1243 Indicates that a fork system call was executed.
1246 Indicates that a vfork system call was executed.
1248 vforkdone stop reason
1249 Indicates that a vfork child of the specified process has executed
1250 an exec or exit, allowing the vfork parent to resume execution.
1252 fork-events and vfork-events features in qSupported
1253 The qSupported packet allows GDB to request support for fork and
1254 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1255 and the qSupported response can contain the corresponding
1256 'stubfeatures'. Set and show commands can be used to display
1257 whether these features are enabled.
1259 * Extended-remote fork events
1261 ** GDB now has support for fork events on extended-remote Linux
1262 targets. For targets with Linux kernels 2.5.60 and later, this
1263 enables follow-fork-mode and detach-on-fork for both fork and
1264 vfork, as well as fork and vfork catchpoints.
1266 * The info record command now shows the recording format and the
1267 branch tracing configuration for the current thread when using
1268 the btrace record target.
1269 For the BTS format, it shows the ring buffer size.
1271 * GDB now has support for DTrace USDT (Userland Static Defined
1272 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1274 * GDB now supports access to vector registers on S/390 GNU/Linux
1277 * Removed command line options
1279 -xdb HP-UX XDB compatibility mode.
1281 * Removed targets and native configurations
1283 HP/PA running HP-UX hppa*-*-hpux*
1284 Itanium running HP-UX ia64-*-hpux*
1286 * New configure options
1289 This configure option allows the user to build GDB with support for
1290 Intel Processor Trace (default: auto). This requires libipt.
1292 --with-libipt-prefix=PATH
1293 Specify the path to the version of libipt that GDB should use.
1294 $PATH/include should contain the intel-pt.h header and
1295 $PATH/lib should contain the libipt.so library.
1297 *** Changes in GDB 7.9.1
1301 ** Xmethods can now specify a result type.
1303 *** Changes in GDB 7.9
1305 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1309 ** You can now access frame registers from Python scripts.
1310 ** New attribute 'producer' for gdb.Symtab objects.
1311 ** gdb.Objfile objects have a new attribute "progspace",
1312 which is the gdb.Progspace object of the containing program space.
1313 ** gdb.Objfile objects have a new attribute "owner".
1314 ** gdb.Objfile objects have a new attribute "build_id",
1315 which is the build ID generated when the file was built.
1316 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1317 ** A new event "gdb.clear_objfiles" has been added, triggered when
1318 selecting a new file to debug.
1319 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1320 ** New function gdb.lookup_objfile.
1322 New events which are triggered when GDB modifies the state of the
1325 ** gdb.events.inferior_call_pre: Function call is about to be made.
1326 ** gdb.events.inferior_call_post: Function call has just been made.
1327 ** gdb.events.memory_changed: A memory location has been altered.
1328 ** gdb.events.register_changed: A register has been altered.
1330 * New Python-based convenience functions:
1332 ** $_caller_is(name [, number_of_frames])
1333 ** $_caller_matches(regexp [, number_of_frames])
1334 ** $_any_caller_is(name [, number_of_frames])
1335 ** $_any_caller_matches(regexp [, number_of_frames])
1337 * GDB now supports the compilation and injection of source code into
1338 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1339 to compile the source code to object code, and if successful, inject
1340 and execute that code within the current context of the inferior.
1341 Currently the C language is supported. The commands used to
1342 interface with this new feature are:
1344 compile code [-raw|-r] [--] [source code]
1345 compile file [-raw|-r] filename
1349 demangle [-l language] [--] name
1350 Demangle "name" in the specified language, or the current language
1351 if elided. This command is renamed from the "maint demangle" command.
1352 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1353 as "maint demangler-warning".
1355 queue-signal signal-name-or-number
1356 Queue a signal to be delivered to the thread when it is resumed.
1358 add-auto-load-scripts-directory directory
1359 Add entries to the list of directories from which to load auto-loaded
1362 maint print user-registers
1363 List all currently available "user" registers.
1365 compile code [-r|-raw] [--] [source code]
1366 Compile, inject, and execute in the inferior the executable object
1367 code produced by compiling the provided source code.
1369 compile file [-r|-raw] filename
1370 Compile and inject into the inferior the executable object code
1371 produced by compiling the source code stored in the filename
1374 * On resume, GDB now always passes the signal the program had stopped
1375 for to the thread the signal was sent to, even if the user changed
1376 threads before resuming. Previously GDB would often (but not
1377 always) deliver the signal to the thread that happens to be current
1380 * Conversely, the "signal" command now consistently delivers the
1381 requested signal to the current thread. GDB now asks for
1382 confirmation if the program had stopped for a signal and the user
1383 switched threads meanwhile.
1385 * "breakpoint always-inserted" modes "off" and "auto" merged.
1387 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1388 won't remove breakpoints from the target until all threads stop,
1389 even in non-stop mode. The "auto" mode has been removed, and "off"
1390 is now the default mode.
1394 set debug symbol-lookup
1395 show debug symbol-lookup
1396 Control display of debugging info regarding symbol lookup.
1400 ** The -list-thread-groups command outputs an exit-code field for
1401 inferiors that have exited.
1405 MIPS SDE mips*-sde*-elf*
1409 Support for these obsolete configurations has been removed.
1411 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1412 SGI Irix-5.x mips-*-irix5*
1413 SGI Irix-6.x mips-*-irix6*
1414 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1415 VAX running Ultrix vax-*-ultrix*
1417 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1418 and "assf"), have been removed. Use the "sharedlibrary" command, or
1419 its alias "share", instead.
1421 *** Changes in GDB 7.8
1423 * New command line options
1426 This is an alias for the --data-directory option.
1428 * GDB supports printing and modifying of variable length automatic arrays
1429 as specified in ISO C99.
1431 * The ARM simulator now supports instruction level tracing
1432 with or without disassembly.
1436 GDB now has support for scripting using Guile. Whether this is
1437 available is determined at configure time.
1438 Guile version 2.0 or greater is required.
1439 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1441 * New commands (for set/show, see "New options" below)
1445 Invoke CODE by passing it to the Guile interpreter.
1449 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1451 info auto-load guile-scripts [regexp]
1452 Print the list of automatically loaded Guile scripts.
1454 * The source command is now capable of sourcing Guile scripts.
1455 This feature is dependent on the debugger being built with Guile support.
1459 set print symbol-loading (off|brief|full)
1460 show print symbol-loading
1461 Control whether to print informational messages when loading symbol
1462 information for a file. The default is "full", but when debugging
1463 programs with large numbers of shared libraries the amount of output
1464 becomes less useful.
1466 set guile print-stack (none|message|full)
1467 show guile print-stack
1468 Show a stack trace when an error is encountered in a Guile script.
1470 set auto-load guile-scripts (on|off)
1471 show auto-load guile-scripts
1472 Control auto-loading of Guile script files.
1474 maint ada set ignore-descriptive-types (on|off)
1475 maint ada show ignore-descriptive-types
1476 Control whether the debugger should ignore descriptive types in Ada
1477 programs. The default is not to ignore the descriptive types. See
1478 the user manual for more details on descriptive types and the intended
1479 usage of this option.
1481 set auto-connect-native-target
1483 Control whether GDB is allowed to automatically connect to the
1484 native target for the run, attach, etc. commands when not connected
1485 to any target yet. See also "target native" below.
1487 set record btrace replay-memory-access (read-only|read-write)
1488 show record btrace replay-memory-access
1489 Control what memory accesses are allowed during replay.
1491 maint set target-async (on|off)
1492 maint show target-async
1493 This controls whether GDB targets operate in synchronous or
1494 asynchronous mode. Normally the default is asynchronous, if it is
1495 available; but this can be changed to more easily debug problems
1496 occurring only in synchronous mode.
1498 set mi-async (on|off)
1500 Control whether MI asynchronous mode is preferred. This supersedes
1501 "set target-async" of previous GDB versions.
1503 * "set target-async" is deprecated as a CLI option and is now an alias
1504 for "set mi-async" (only puts MI into async mode).
1506 * Background execution commands (e.g., "c&", "s&", etc.) are now
1507 possible ``out of the box'' if the target supports them. Previously
1508 the user would need to explicitly enable the possibility with the
1509 "set target-async on" command.
1511 * New features in the GDB remote stub, GDBserver
1513 ** New option --debug-format=option1[,option2,...] allows one to add
1514 additional text to each output. At present only timestamps
1515 are supported: --debug-format=timestamps.
1516 Timestamps can also be turned on with the
1517 "monitor set debug-format timestamps" command from GDB.
1519 * The 'record instruction-history' command now starts counting instructions
1520 at one. This also affects the instruction ranges reported by the
1521 'record function-call-history' command when given the /i modifier.
1523 * The command 'record function-call-history' supports a new modifier '/c' to
1524 indent the function names based on their call stack depth.
1525 The fields for the '/i' and '/l' modifier have been reordered.
1526 The source line range is now prefixed with 'at'.
1527 The instruction range is now prefixed with 'inst'.
1528 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1529 "record instruction-history" and "list" commands.
1531 * The ranges given as arguments to the 'record function-call-history' and
1532 'record instruction-history' commands are now inclusive.
1534 * The btrace record target now supports the 'record goto' command.
1535 For locations inside the execution trace, the back trace is computed
1536 based on the information stored in the execution trace.
1538 * The btrace record target supports limited reverse execution and replay.
1539 The target does not record data and therefore does not allow reading
1540 memory or registers.
1542 * The "catch syscall" command now works on s390*-linux* targets.
1544 * The "compare-sections" command is no longer specific to target
1545 remote. It now works with all targets.
1547 * All native targets are now consistently called "native".
1548 Consequently, the "target child", "target GNU", "target djgpp",
1549 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1550 commands have been replaced with "target native". The QNX/NTO port
1551 leaves the "procfs" target in place and adds a "native" target for
1552 consistency with other ports. The impact on users should be minimal
1553 as these commands previously either throwed an error, or were
1554 no-ops. The target's name is visible in the output of the following
1555 commands: "help target", "info target", "info files", "maint print
1558 * The "target native" command now connects to the native target. This
1559 can be used to launch native programs even when "set
1560 auto-connect-native-target" is set to off.
1562 * GDB now supports access to Intel MPX registers on GNU/Linux.
1564 * Support for Intel AVX-512 registers on GNU/Linux.
1565 Support displaying and modifying Intel AVX-512 registers
1566 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1568 * New remote packets
1570 qXfer:btrace:read's annex
1571 The qXfer:btrace:read packet supports a new annex 'delta' to read
1572 branch trace incrementally.
1576 ** Valid Python operations on gdb.Value objects representing
1577 structs/classes invoke the corresponding overloaded operators if
1579 ** New `Xmethods' feature in the Python API. Xmethods are
1580 additional methods or replacements for existing methods of a C++
1581 class. This feature is useful for those cases where a method
1582 defined in C++ source code could be inlined or optimized out by
1583 the compiler, making it unavailable to GDB.
1586 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1588 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1589 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1590 its alias "share", instead.
1592 * The commands "set remotebaud" and "show remotebaud" are no longer
1593 supported. Use "set serial baud" and "show serial baud" (respectively)
1598 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1599 target-async". The latter is left as a deprecated alias of the
1600 former for backward compatibility. If the target supports it,
1601 CLI background execution commands are now always possible by
1602 default, independently of whether the frontend stated a
1603 preference for asynchronous execution with "-gdb-set mi-async".
1604 Previously "-gdb-set target-async off" affected both MI execution
1605 commands and CLI execution commands.
1607 *** Changes in GDB 7.7
1609 * Improved support for process record-replay and reverse debugging on
1610 arm*-linux* targets. Support for thumb32 and syscall instruction
1611 recording has been added.
1613 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1615 * GDB now supports Fission DWP file format version 2.
1616 http://gcc.gnu.org/wiki/DebugFission
1618 * New convenience function "$_isvoid", to check whether an expression
1619 is void. A void expression is an expression where the type of the
1620 result is "void". For example, some convenience variables may be
1621 "void" when evaluated (e.g., "$_exitcode" before the execution of
1622 the program being debugged; or an undefined convenience variable).
1623 Another example, when calling a function whose return type is
1626 * The "maintenance print objfiles" command now takes an optional regexp.
1628 * The "catch syscall" command now works on arm*-linux* targets.
1630 * GDB now consistently shows "<not saved>" when printing values of
1631 registers the debug info indicates have not been saved in the frame
1632 and there's nowhere to retrieve them from
1633 (callee-saved/call-clobbered registers):
1638 (gdb) info registers rax
1641 Before, the former would print "<optimized out>", and the latter
1642 "*value not available*".
1644 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1649 ** Frame filters and frame decorators have been added.
1650 ** Temporary breakpoints are now supported.
1651 ** Line tables representation has been added.
1652 ** New attribute 'parent_type' for gdb.Field objects.
1653 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1654 ** New attribute 'name' for gdb.Type objects.
1658 Nios II ELF nios2*-*-elf
1659 Nios II GNU/Linux nios2*-*-linux
1660 Texas Instruments MSP430 msp430*-*-elf
1662 * Removed native configurations
1664 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1665 been removed. ELF variants of these configurations are kept supported.
1667 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1668 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1669 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1670 i[34567]86-*-openbsd3.[0-3]
1671 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1672 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1673 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1677 Like "catch throw", but catches a re-thrown exception.
1678 maint check-psymtabs
1679 Renamed from old "maint check-symtabs".
1681 Perform consistency checks on symtabs.
1682 maint expand-symtabs
1683 Expand symtabs matching an optional regexp.
1686 Display the details of GDB configure-time options.
1688 maint set|show per-command
1689 maint set|show per-command space
1690 maint set|show per-command time
1691 maint set|show per-command symtab
1692 Enable display of per-command gdb resource usage.
1694 remove-symbol-file FILENAME
1695 remove-symbol-file -a ADDRESS
1696 Remove a symbol file added via add-symbol-file. The file to remove
1697 can be identified by its filename or by an address that lies within
1698 the boundaries of this symbol file in memory.
1701 info exceptions REGEXP
1702 Display the list of Ada exceptions defined in the program being
1703 debugged. If provided, only the exceptions whose names match REGEXP
1708 set debug symfile off|on
1710 Control display of debugging info regarding reading symbol files and
1711 symbol tables within those files
1713 set print raw frame-arguments
1714 show print raw frame-arguments
1715 Set/show whether to print frame arguments in raw mode,
1716 disregarding any defined pretty-printers.
1718 set remote trace-status-packet
1719 show remote trace-status-packet
1720 Set/show the use of remote protocol qTStatus packet.
1724 Control display of debugging messages related to Nios II targets.
1728 Control whether target-assisted range stepping is enabled.
1730 set startup-with-shell
1731 show startup-with-shell
1732 Specifies whether Unix child processes are started via a shell or
1737 Use the target memory cache for accesses to the code segment. This
1738 improves performance of remote debugging (particularly disassembly).
1740 * You can now use a literal value 'unlimited' for options that
1741 interpret 0 or -1 as meaning "unlimited". E.g., "set
1742 trace-buffer-size unlimited" is now an alias for "set
1743 trace-buffer-size -1" and "set height unlimited" is now an alias for
1746 * The "set debug symtab-create" debugging option of GDB has been changed to
1747 accept a verbosity level. 0 means "off", 1 provides basic debugging
1748 output, and values of 2 or greater provides more verbose output.
1750 * New command-line options
1752 Display the details of GDB configure-time options.
1754 * The command 'tsave' can now support new option '-ctf' to save trace
1755 buffer in Common Trace Format.
1757 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1760 * GDB now implements the the C++ 'typeid' operator.
1762 * The new convenience variable $_exception holds the exception being
1763 thrown or caught at an exception-related catchpoint.
1765 * The exception-related catchpoints, like "catch throw", now accept a
1766 regular expression which can be used to filter exceptions by type.
1768 * The new convenience variable $_exitsignal is automatically set to
1769 the terminating signal number when the program being debugged dies
1770 due to an uncaught signal.
1774 ** All MI commands now accept an optional "--language" option.
1775 Support for this feature can be verified by using the "-list-features"
1776 command, which should contain "language-option".
1778 ** The new command -info-gdb-mi-command allows the user to determine
1779 whether a GDB/MI command is supported or not.
1781 ** The "^error" result record returned when trying to execute an undefined
1782 GDB/MI command now provides a variable named "code" whose content is the
1783 "undefined-command" error code. Support for this feature can be verified
1784 by using the "-list-features" command, which should contain
1785 "undefined-command-error-code".
1787 ** The -trace-save MI command can optionally save trace buffer in Common
1790 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1792 ** The command -data-list-register-values now accepts an optional
1793 "--skip-unavailable" option. When used, only the available registers
1796 ** The new command -trace-frame-collected dumps collected variables,
1797 computed expressions, tvars, memory and registers in a traceframe.
1799 ** The commands -stack-list-locals, -stack-list-arguments and
1800 -stack-list-variables now accept an option "--skip-unavailable".
1801 When used, only the available locals or arguments are displayed.
1803 ** The -exec-run command now accepts an optional "--start" option.
1804 When used, the command follows the same semantics as the "start"
1805 command, stopping the program's execution at the start of its
1806 main subprogram. Support for this feature can be verified using
1807 the "-list-features" command, which should contain
1808 "exec-run-start-option".
1810 ** The new commands -catch-assert and -catch-exceptions insert
1811 catchpoints stopping the program when Ada exceptions are raised.
1813 ** The new command -info-ada-exceptions provides the equivalent of
1814 the new "info exceptions" command.
1816 * New system-wide configuration scripts
1817 A GDB installation now provides scripts suitable for use as system-wide
1818 configuration scripts for the following systems:
1822 * GDB now supports target-assigned range stepping with remote targets.
1823 This improves the performance of stepping source lines by reducing
1824 the number of control packets from/to GDB. See "New remote packets"
1827 * GDB now understands the element 'tvar' in the XML traceframe info.
1828 It has the id of the collected trace state variables.
1830 * On S/390 targets that provide the transactional-execution feature,
1831 the program interruption transaction diagnostic block (TDB) is now
1832 represented as a number of additional "registers" in GDB.
1834 * New remote packets
1838 The vCont packet supports a new 'r' action, that tells the remote
1839 stub to step through an address range itself, without GDB
1840 involvemement at each single-step.
1842 qXfer:libraries-svr4:read's annex
1843 The previously unused annex of the qXfer:libraries-svr4:read packet
1844 is now used to support passing an argument list. The remote stub
1845 reports support for this argument list to GDB's qSupported query.
1846 The defined arguments are "start" and "prev", used to reduce work
1847 necessary for library list updating, resulting in significant
1850 * New features in the GDB remote stub, GDBserver
1852 ** GDBserver now supports target-assisted range stepping. Currently
1853 enabled on x86/x86_64 GNU/Linux targets.
1855 ** GDBserver now adds element 'tvar' in the XML in the reply to
1856 'qXfer:traceframe-info:read'. It has the id of the collected
1857 trace state variables.
1859 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1862 * New 'z' formatter for printing and examining memory, this displays the
1863 value as hexadecimal zero padded on the left to the size of the type.
1865 * GDB can now use Windows x64 unwinding data.
1867 * The "set remotebaud" command has been replaced by "set serial baud".
1868 Similarly, "show remotebaud" has been replaced by "show serial baud".
1869 The "set remotebaud" and "show remotebaud" commands are still available
1870 to provide backward compatibility with older versions of GDB.
1872 *** Changes in GDB 7.6
1874 * Target record has been renamed to record-full.
1875 Record/replay is now enabled with the "record full" command.
1876 This also affects settings that are associated with full record/replay
1877 that have been moved from "set/show record" to "set/show record full":
1879 set|show record full insn-number-max
1880 set|show record full stop-at-limit
1881 set|show record full memory-query
1883 * A new record target "record-btrace" has been added. The new target
1884 uses hardware support to record the control-flow of a process. It
1885 does not support replaying the execution, but it implements the
1886 below new commands for investigating the recorded execution log.
1887 This new recording method can be enabled using:
1891 The "record-btrace" target is only available on Intel Atom processors
1892 and requires a Linux kernel 2.6.32 or later.
1894 * Two new commands have been added for record/replay to give information
1895 about the recorded execution without having to replay the execution.
1896 The commands are only supported by "record btrace".
1898 record instruction-history prints the execution history at
1899 instruction granularity
1901 record function-call-history prints the execution history at
1902 function granularity
1904 * New native configurations
1906 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1907 FreeBSD/powerpc powerpc*-*-freebsd
1908 x86_64/Cygwin x86_64-*-cygwin*
1909 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1913 ARM AArch64 aarch64*-*-elf
1914 ARM AArch64 GNU/Linux aarch64*-*-linux
1915 Lynx 178 PowerPC powerpc-*-lynx*178
1916 x86_64/Cygwin x86_64-*-cygwin*
1917 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1919 * If the configured location of system.gdbinit file (as given by the
1920 --with-system-gdbinit option at configure time) is in the
1921 data-directory (as specified by --with-gdb-datadir at configure
1922 time) or in one of its subdirectories, then GDB will look for the
1923 system-wide init file in the directory specified by the
1924 --data-directory command-line option.
1926 * New command line options:
1928 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1929 other initialization files, unlike -nx which disables all of them.
1931 * Removed command line options
1933 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1936 * The 'ptype' and 'whatis' commands now accept an argument to control
1939 * 'info proc' now works on some core files.
1943 ** Vectors can be created with gdb.Type.vector.
1945 ** Python's atexit.register now works in GDB.
1947 ** Types can be pretty-printed via a Python API.
1949 ** Python 3 is now supported (in addition to Python 2.4 or later)
1951 ** New class gdb.Architecture exposes GDB's internal representation
1952 of architecture in the Python API.
1954 ** New method Frame.architecture returns the gdb.Architecture object
1955 corresponding to the frame's architecture.
1957 * New Python-based convenience functions:
1959 ** $_memeq(buf1, buf2, length)
1960 ** $_streq(str1, str2)
1962 ** $_regex(str, regex)
1964 * The 'cd' command now defaults to using '~' (the home directory) if not
1967 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1968 default for GCC since November 2000.
1970 * The command 'forward-search' can now be abbreviated as 'fo'.
1972 * The command 'info tracepoints' can now display 'installed on target'
1973 or 'not installed on target' for each non-pending location of tracepoint.
1975 * New configure options
1977 --enable-libmcheck/--disable-libmcheck
1978 By default, development versions are built with -lmcheck on hosts
1979 that support it, in order to help track memory corruption issues.
1980 Release versions, on the other hand, are built without -lmcheck
1981 by default. The --enable-libmcheck/--disable-libmcheck configure
1982 options allow the user to override that default.
1983 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1984 This configure option allows the user to build GDB with
1985 libbabeltrace using which GDB can read Common Trace Format data.
1987 * New commands (for set/show, see "New options" below)
1990 Catch signals. This is similar to "handle", but allows commands and
1991 conditions to be attached.
1994 List the BFDs known to GDB.
1996 python-interactive [command]
1998 Start a Python interactive prompt, or evaluate the optional command
1999 and print the result of expressions.
2002 "py" is a new alias for "python".
2004 enable type-printer [name]...
2005 disable type-printer [name]...
2006 Enable or disable type printers.
2010 ** For the Renesas Super-H architecture, the "regs" command has been removed
2011 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2016 set print type methods (on|off)
2017 show print type methods
2018 Control whether method declarations are displayed by "ptype".
2019 The default is to show them.
2021 set print type typedefs (on|off)
2022 show print type typedefs
2023 Control whether typedef definitions are displayed by "ptype".
2024 The default is to show them.
2026 set filename-display basename|relative|absolute
2027 show filename-display
2028 Control the way in which filenames is displayed.
2029 The default is "relative", which preserves previous behavior.
2031 set trace-buffer-size
2032 show trace-buffer-size
2033 Request target to change the size of trace buffer.
2035 set remote trace-buffer-size-packet auto|on|off
2036 show remote trace-buffer-size-packet
2037 Control the use of the remote protocol `QTBuffer:size' packet.
2041 Control display of debugging messages related to ARM AArch64.
2044 set debug coff-pe-read
2045 show debug coff-pe-read
2046 Control display of debugging messages related to reading of COFF/PE
2051 Control display of debugging messages related to Mach-O symbols
2054 set debug notification
2055 show debug notification
2056 Control display of debugging info for async remote notification.
2060 ** Command parameter changes are now notified using new async record
2061 "=cmd-param-changed".
2062 ** Trace frame changes caused by command "tfind" are now notified using
2063 new async record "=traceframe-changed".
2064 ** The creation, deletion and modification of trace state variables
2065 are now notified using new async records "=tsv-created",
2066 "=tsv-deleted" and "=tsv-modified".
2067 ** The start and stop of process record are now notified using new
2068 async record "=record-started" and "=record-stopped".
2069 ** Memory changes are now notified using new async record
2071 ** The data-disassemble command response will include a "fullname" field
2072 containing the absolute file name when source has been requested.
2073 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2074 command, to allow pattern filling of memory areas.
2075 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2076 library load/unload events.
2077 ** The response to breakpoint commands and breakpoint async records
2078 includes an "installed" field containing a boolean state about each
2079 non-pending tracepoint location is whether installed on target or not.
2080 ** Output of the "-trace-status" command includes a "trace-file" field
2081 containing the name of the trace file being examined. This field is
2082 optional, and only present when examining a trace file.
2083 ** The "fullname" field is now always present along with the "file" field,
2084 even if the file cannot be found by GDB.
2086 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2087 You must have the LZMA library available when configuring GDB for this
2088 feature to be enabled. For more information, see:
2089 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2091 * New remote packets
2094 Set the size of trace buffer. The remote stub reports support for this
2095 packet to gdb's qSupported query.
2098 Enable Branch Trace Store (BTS)-based branch tracing for the current
2099 thread. The remote stub reports support for this packet to gdb's
2103 Disable branch tracing for the current thread. The remote stub reports
2104 support for this packet to gdb's qSupported query.
2107 Read the traced branches for the current thread. The remote stub
2108 reports support for this packet to gdb's qSupported query.
2110 *** Changes in GDB 7.5
2112 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2113 for more x32 ABI info.
2115 * GDB now supports access to MIPS DSP registers on Linux targets.
2117 * GDB now supports debugging microMIPS binaries.
2119 * The "info os" command on GNU/Linux can now display information on
2120 several new classes of objects managed by the operating system:
2121 "info os procgroups" lists process groups
2122 "info os files" lists file descriptors
2123 "info os sockets" lists internet-domain sockets
2124 "info os shm" lists shared-memory regions
2125 "info os semaphores" lists semaphores
2126 "info os msg" lists message queues
2127 "info os modules" lists loaded kernel modules
2129 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2130 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2131 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2132 options and inspect the probe arguments using the new $_probe_arg family
2133 of convenience variables. You can obtain more information about SystemTap
2134 in <http://sourceware.org/systemtap/>.
2136 * GDB now supports reversible debugging on ARM, it allows you to
2137 debug basic ARM and THUMB instructions, and provides
2138 record/replay support.
2140 * The option "symbol-reloading" has been deleted as it is no longer used.
2144 ** GDB commands implemented in Python can now be put in command class
2147 ** The "maint set python print-stack on|off" is now deleted.
2149 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2150 apply "flag enum"-style pretty-printing to any enum.
2152 ** gdb.lookup_symbol can now work when there is no current frame.
2154 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2155 the source at which the symbol was defined.
2157 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2158 method 'value'. The former indicates whether the symbol needs a
2159 frame in order to compute its value, and the latter computes the
2162 ** A new method 'referenced_value' on gdb.Value objects which can
2163 dereference pointer as well as C++ reference values.
2165 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2166 which return the global and static blocks (as gdb.Block objects),
2167 of the underlying symbol table, respectively.
2169 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2170 object associated with a PC value.
2172 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2173 of the address range occupied by code for the current source line.
2175 * Go language support.
2176 GDB now supports debugging programs written in the Go programming
2179 * GDBserver now supports stdio connections.
2180 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2182 * The binary "gdbtui" can no longer be built or installed.
2183 Use "gdb -tui" instead.
2185 * GDB will now print "flag" enums specially. A flag enum is one where
2186 all the enumerator values have no bits in common when pairwise
2187 "and"ed. When printing a value whose type is a flag enum, GDB will
2188 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2189 (gdb) print (enum E) 3
2192 * The filename part of a linespec will now match trailing components
2193 of a source file name. For example, "break gcc/expr.c:1000" will
2194 now set a breakpoint in build/gcc/expr.c, but not
2195 build/libcpp/expr.c.
2197 * The "info proc" and "generate-core-file" commands will now also
2198 work on remote targets connected to GDBserver on Linux.
2200 * The command "info catch" has been removed. It has been disabled
2201 since December 2007.
2203 * The "catch exception" and "catch assert" commands now accept
2204 a condition at the end of the command, much like the "break"
2205 command does. For instance:
2207 (gdb) catch exception Constraint_Error if Barrier = True
2209 Previously, it was possible to add a condition to such catchpoints,
2210 but it had to be done as a second step, after the catchpoint had been
2211 created, using the "condition" command.
2213 * The "info static-tracepoint-marker" command will now also work on
2214 native Linux targets with in-process agent.
2216 * GDB can now set breakpoints on inlined functions.
2218 * The .gdb_index section has been updated to include symbols for
2219 inlined functions. GDB will ignore older .gdb_index sections by
2220 default, which could cause symbol files to be loaded more slowly
2221 until their .gdb_index sections can be recreated. The new command
2222 "set use-deprecated-index-sections on" will cause GDB to use any older
2223 .gdb_index sections it finds. This will restore performance, but the
2224 ability to set breakpoints on inlined functions will be lost in symbol
2225 files with older .gdb_index sections.
2227 The .gdb_index section has also been updated to record more information
2228 about each symbol. This speeds up the "info variables", "info functions"
2229 and "info types" commands when used with programs having the .gdb_index
2230 section, as well as speeding up debugging with shared libraries using
2231 the .gdb_index section.
2233 * Ada support for GDB/MI Variable Objects has been added.
2235 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2240 ** New command -info-os is the MI equivalent of "info os".
2242 ** Output logs ("set logging" and related) now include MI output.
2246 ** "set use-deprecated-index-sections on|off"
2247 "show use-deprecated-index-sections on|off"
2248 Controls the use of deprecated .gdb_index sections.
2250 ** "catch load" and "catch unload" can be used to stop when a shared
2251 library is loaded or unloaded, respectively.
2253 ** "enable count" can be used to auto-disable a breakpoint after
2256 ** "info vtbl" can be used to show the virtual method tables for
2257 C++ and Java objects.
2259 ** "explore" and its sub commands "explore value" and "explore type"
2260 can be used to recursively explore values and types of
2261 expressions. These commands are available only if GDB is
2262 configured with '--with-python'.
2264 ** "info auto-load" shows status of all kinds of auto-loaded files,
2265 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2266 sequences of commands files, "info auto-load python-scripts"
2267 shows status of auto-loading Python script files,
2268 "info auto-load local-gdbinit" shows status of loading init file
2269 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2270 status of inferior specific thread debugging shared library loading.
2272 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2273 and "show auto-load-scripts" commands have been deprecated, use their
2274 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2275 and "show auto-load python-scripts" counterparts instead.
2277 ** "dprintf location,format,args..." creates a dynamic printf, which
2278 is basically a breakpoint that does a printf and immediately
2279 resumes your program's execution, so it is like a printf that you
2280 can insert dynamically at runtime instead of at compiletime.
2282 ** "set print symbol"
2284 Controls whether GDB attempts to display the symbol, if any,
2285 corresponding to addresses it prints. This defaults to "on", but
2286 you can set it to "off" to restore GDB's previous behavior.
2288 * Deprecated commands
2290 ** For the Renesas Super-H architecture, the "regs" command has been
2291 deprecated, and "info all-registers" should be used instead.
2295 Renesas RL78 rl78-*-elf
2296 HP OpenVMS ia64 ia64-hp-openvms*
2298 * GDBserver supports evaluation of breakpoint conditions. When
2299 support is advertised by GDBserver, GDB may be told to send the
2300 breakpoint conditions in bytecode form to GDBserver. GDBserver
2301 will only report the breakpoint trigger to GDB when its condition
2306 set mips compression
2307 show mips compression
2308 Select the compressed ISA encoding used in functions that have no symbol
2309 information available. The encoding can be set to either of:
2312 and is updated automatically from ELF file flags if available.
2314 set breakpoint condition-evaluation
2315 show breakpoint condition-evaluation
2316 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2317 GDBserver ("target"). Default option "auto" chooses the most efficient
2319 This option can improve debugger efficiency depending on the speed of the
2323 Disable auto-loading globally.
2326 Show auto-loading setting of all kinds of auto-loaded files.
2328 set auto-load gdb-scripts on|off
2329 show auto-load gdb-scripts
2330 Control auto-loading of GDB canned sequences of commands files.
2332 set auto-load python-scripts on|off
2333 show auto-load python-scripts
2334 Control auto-loading of Python script files.
2336 set auto-load local-gdbinit on|off
2337 show auto-load local-gdbinit
2338 Control loading of init file (.gdbinit) from current directory.
2340 set auto-load libthread-db on|off
2341 show auto-load libthread-db
2342 Control auto-loading of inferior specific thread debugging shared library.
2344 set auto-load scripts-directory <dir1>[:<dir2>...]
2345 show auto-load scripts-directory
2346 Set a list of directories from which to load auto-loaded scripts.
2347 Automatically loaded Python scripts and GDB scripts are located in one
2348 of the directories listed by this option.
2349 The delimiter (':' above) may differ according to the host platform.
2351 set auto-load safe-path <dir1>[:<dir2>...]
2352 show auto-load safe-path
2353 Set a list of directories from which it is safe to auto-load files.
2354 The delimiter (':' above) may differ according to the host platform.
2356 set debug auto-load on|off
2357 show debug auto-load
2358 Control display of debugging info for auto-loading the files above.
2360 set dprintf-style gdb|call|agent
2362 Control the way in which a dynamic printf is performed; "gdb"
2363 requests a GDB printf command, while "call" causes dprintf to call a
2364 function in the inferior. "agent" requests that the target agent
2365 (such as GDBserver) do the printing.
2367 set dprintf-function <expr>
2368 show dprintf-function
2369 set dprintf-channel <expr>
2370 show dprintf-channel
2371 Set the function and optional first argument to the call when using
2372 the "call" style of dynamic printf.
2374 set disconnected-dprintf on|off
2375 show disconnected-dprintf
2376 Control whether agent-style dynamic printfs continue to be in effect
2377 after GDB disconnects.
2379 * New configure options
2381 --with-auto-load-dir
2382 Configure default value for the 'set auto-load scripts-directory'
2383 setting above. It defaults to '$debugdir:$datadir/auto-load',
2384 $debugdir representing global debugging info directories (available
2385 via 'show debug-file-directory') and $datadir representing GDB's data
2386 directory (available via 'show data-directory').
2388 --with-auto-load-safe-path
2389 Configure default value for the 'set auto-load safe-path' setting
2390 above. It defaults to the --with-auto-load-dir setting.
2392 --without-auto-load-safe-path
2393 Set 'set auto-load safe-path' to '/', effectively disabling this
2396 * New remote packets
2398 z0/z1 conditional breakpoints extension
2400 The z0/z1 breakpoint insertion packets have been extended to carry
2401 a list of conditional expressions over to the remote stub depending on the
2402 condition evaluation mode. The use of this extension can be controlled
2403 via the "set remote conditional-breakpoints-packet" command.
2407 Specify the signals which the remote stub may pass to the debugged
2408 program without GDB involvement.
2410 * New command line options
2412 --init-command=FILE, -ix Like --command, -x but execute it
2413 before loading inferior.
2414 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2415 execute it before loading inferior.
2417 *** Changes in GDB 7.4
2419 * GDB now handles ambiguous linespecs more consistently; the existing
2420 FILE:LINE support has been expanded to other types of linespecs. A
2421 breakpoint will now be set on all matching locations in all
2422 inferiors, and locations will be added or removed according to
2425 * GDB now allows you to skip uninteresting functions and files when
2426 stepping with the "skip function" and "skip file" commands.
2428 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2429 and "show remote hardware-watchpoint-length-limit". These allows to
2430 set or show the maximum length limit (in bytes) of a remote
2431 target hardware watchpoint.
2433 This allows e.g. to use "unlimited" hardware watchpoints with the
2434 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2435 watchpoints are slower than real hardware watchpoints but are
2436 significantly faster than gdb software watchpoints.
2440 ** The register_pretty_printer function in module gdb.printing now takes
2441 an optional `replace' argument. If True, the new printer replaces any
2444 ** The "maint set python print-stack on|off" command has been
2445 deprecated and will be deleted in GDB 7.5.
2446 A new command: "set python print-stack none|full|message" has
2447 replaced it. Additionally, the default for "print-stack" is
2448 now "message", which just prints the error message without
2451 ** A prompt substitution hook (prompt_hook) is now available to the
2454 ** A new Python module, gdb.prompt has been added to the GDB Python
2455 modules library. This module provides functionality for
2456 escape sequences in prompts (used by set/show
2457 extended-prompt). These escape sequences are replaced by their
2458 corresponding value.
2460 ** Python commands and convenience-functions located in
2461 'data-directory'/python/gdb/command and
2462 'data-directory'/python/gdb/function are now automatically loaded
2465 ** Blocks now provide four new attributes. global_block and
2466 static_block will return the global and static blocks
2467 respectively. is_static and is_global are boolean attributes
2468 that indicate if the block is one of those two types.
2470 ** Symbols now provide the "type" attribute, the type of the symbol.
2472 ** The "gdb.breakpoint" function has been deprecated in favor of
2475 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2476 of a function. This class is based on the "finish" command
2477 available in the CLI.
2479 ** Type objects for struct and union types now allow access to
2480 the fields using standard Python dictionary (mapping) methods.
2481 For example, "some_type['myfield']" now works, as does
2482 "some_type.items()".
2484 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2487 ** A new function, "deep_items" has been added to the gdb.types
2488 module in the GDB Python modules library. This function returns
2489 an iterator over the fields of a struct or union type. Unlike
2490 the standard Python "iteritems" method, it will recursively traverse
2491 any anonymous fields.
2495 ** "*stopped" events can report several new "reason"s, such as
2498 ** Breakpoint changes are now notified using new async records, like
2499 "=breakpoint-modified".
2501 ** New command -ada-task-info.
2503 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2504 $sdir specifies the default system locations of shared libraries.
2505 $pdir specifies the directory where the libpthread used by the application
2508 GDB no longer looks in $sdir and $pdir after it has searched the directories
2509 mentioned in libthread-db-search-path. If you want to search those
2510 directories, they must be specified in libthread-db-search-path.
2511 The default value of libthread-db-search-path on GNU/Linux and Solaris
2512 systems is now "$sdir:$pdir".
2514 $pdir is not supported by gdbserver, it is currently ignored.
2515 $sdir is supported by gdbserver.
2517 * New configure option --with-iconv-bin.
2518 When using the internationalization support like the one in the GNU C
2519 library, GDB will invoke the "iconv" program to get a list of supported
2520 character sets. If this program lives in a non-standard location, one can
2521 use this option to specify where to find it.
2523 * When natively debugging programs on PowerPC BookE processors running
2524 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2525 watchpoints, which specify a mask in addition to an address to watch.
2526 The mask specifies that some bits of an address (the bits which are
2527 reset in the mask) should be ignored when matching the address accessed
2528 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2529 section in the user manual for more details.
2531 * The new option --once causes GDBserver to stop listening for connections once
2532 the first connection is made. The listening port used by GDBserver will
2533 become available after that.
2535 * New commands "info macros" and "alias" have been added.
2537 * New function parameters suffix @entry specifies value of function parameter
2538 at the time the function got called. Entry values are available only since
2544 "!" is now an alias of the "shell" command.
2545 Note that no space is needed between "!" and SHELL COMMAND.
2549 watch EXPRESSION mask MASK_VALUE
2550 The watch command now supports the mask argument which allows creation
2551 of masked watchpoints, if the current architecture supports this feature.
2553 info auto-load-scripts [REGEXP]
2554 This command was formerly named "maintenance print section-scripts".
2555 It is now generally useful and is no longer a maintenance-only command.
2557 info macro [-all] [--] MACRO
2558 The info macro command has new options `-all' and `--'. The first for
2559 printing all definitions of a macro. The second for explicitly specifying
2560 the end of arguments and the beginning of the macro name in case the macro
2561 name starts with a hyphen.
2563 collect[/s] EXPRESSIONS
2564 The tracepoint collect command now takes an optional modifier "/s"
2565 that directs it to dereference pointer-to-character types and
2566 collect the bytes of memory up to a zero byte. The behavior is
2567 similar to what you see when you use the regular print command on a
2568 string. An optional integer following the "/s" sets a bound on the
2569 number of bytes that will be collected.
2572 The trace start command now interprets any supplied arguments as a
2573 note to be recorded with the trace run, with an effect similar to
2574 setting the variable trace-notes.
2577 The trace stop command now interprets any arguments as a note to be
2578 mentioned along with the tstatus report that the trace was stopped
2579 with a command. The effect is similar to setting the variable
2582 * Tracepoints can now be enabled and disabled at any time after a trace
2583 experiment has been started using the standard "enable" and "disable"
2584 commands. It is now possible to start a trace experiment with no enabled
2585 tracepoints; GDB will display a warning, but will allow the experiment to
2586 begin, assuming that tracepoints will be enabled as needed while the trace
2589 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2590 locations with 4-byte instructions, when they were previously
2591 limited to locations with instructions of 5 bytes or longer.
2595 set debug dwarf2-read
2596 show debug dwarf2-read
2597 Turns on or off display of debugging messages related to reading
2598 DWARF debug info. The default is off.
2600 set debug symtab-create
2601 show debug symtab-create
2602 Turns on or off display of debugging messages related to symbol table
2603 creation. The default is off.
2606 show extended-prompt
2607 Set the GDB prompt, and allow escape sequences to be inserted to
2608 display miscellaneous information (see 'help set extended-prompt'
2609 for the list of sequences). This prompt (and any information
2610 accessed through the escape sequences) is updated every time the
2611 prompt is displayed.
2613 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2614 show print entry-values
2615 Set printing of frame argument values at function entry. In some cases
2616 GDB can determine the value of function argument which was passed by the
2617 function caller, even if the value was modified inside the called function.
2619 set debug entry-values
2620 show debug entry-values
2621 Control display of debugging info for determining frame argument values at
2622 function entry and virtual tail call frames.
2624 set basenames-may-differ
2625 show basenames-may-differ
2626 Set whether a source file may have multiple base names.
2627 (A "base name" is the name of a file with the directory part removed.
2628 Example: The base name of "/home/user/hello.c" is "hello.c".)
2629 If set, GDB will canonicalize file names (e.g., expand symlinks)
2630 before comparing them. Canonicalization is an expensive operation,
2631 but it allows the same file be known by more than one base name.
2632 If not set (the default), all source files are assumed to have just
2633 one base name, and gdb will do file name comparisons more efficiently.
2639 Set a user name and notes for the current and any future trace runs.
2640 This is useful for long-running and/or disconnected traces, to
2641 inform others (or yourself) as to who is running the trace, supply
2642 contact information, or otherwise explain what is going on.
2644 set trace-stop-notes
2645 show trace-stop-notes
2646 Set a note attached to the trace run, that is displayed when the
2647 trace has been stopped by a tstop command. This is useful for
2648 instance as an explanation, if you are stopping a trace run that was
2649 started by someone else.
2651 * New remote packets
2655 Dynamically enable a tracepoint in a started trace experiment.
2659 Dynamically disable a tracepoint in a started trace experiment.
2663 Set the user and notes of the trace run.
2667 Query the current status of a tracepoint.
2671 Query the minimum length of instruction at which a fast tracepoint may
2674 * Dcache size (number of lines) and line-size are now runtime-configurable
2675 via "set dcache line" and "set dcache line-size" commands.
2679 Texas Instruments TMS320C6x tic6x-*-*
2683 Renesas RL78 rl78-*-elf
2685 *** Changes in GDB 7.3.1
2687 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2689 *** Changes in GDB 7.3
2691 * GDB has a new command: "thread find [REGEXP]".
2692 It finds the thread id whose name, target id, or thread extra info
2693 matches the given regular expression.
2695 * The "catch syscall" command now works on mips*-linux* targets.
2697 * The -data-disassemble MI command now supports modes 2 and 3 for
2698 dumping the instruction opcodes.
2700 * New command line options
2702 -data-directory DIR Specify DIR as the "data-directory".
2703 This is mostly for testing purposes.
2705 * The "maint set python auto-load on|off" command has been renamed to
2706 "set auto-load-scripts on|off".
2708 * GDB has a new command: "set directories".
2709 It is like the "dir" command except that it replaces the
2710 source path list instead of augmenting it.
2712 * GDB now understands thread names.
2714 On GNU/Linux, "info threads" will display the thread name as set by
2715 prctl or pthread_setname_np.
2717 There is also a new command, "thread name", which can be used to
2718 assign a name internally for GDB to display.
2721 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2722 has been integrated into GDB.
2726 ** The function gdb.Write now accepts an optional keyword 'stream'.
2727 This keyword, when provided, will direct the output to either
2728 stdout, stderr, or GDB's logging output.
2730 ** Parameters can now be be sub-classed in Python, and in particular
2731 you may implement the get_set_doc and get_show_doc functions.
2732 This improves how Parameter set/show documentation is processed
2733 and allows for more dynamic content.
2735 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2736 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2737 have an is_valid method.
2739 ** Breakpoints can now be sub-classed in Python, and in particular
2740 you may implement a 'stop' function that is executed each time
2741 the inferior reaches that breakpoint.
2743 ** New function gdb.lookup_global_symbol looks up a global symbol.
2745 ** GDB values in Python are now callable if the value represents a
2746 function. For example, if 'some_value' represents a function that
2747 takes two integer parameters and returns a value, you can call
2748 that function like so:
2750 result = some_value (10,20)
2752 ** Module gdb.types has been added.
2753 It contains a collection of utilities for working with gdb.Types objects:
2754 get_basic_type, has_field, make_enum_dict.
2756 ** Module gdb.printing has been added.
2757 It contains utilities for writing and registering pretty-printers.
2758 New classes: PrettyPrinter, SubPrettyPrinter,
2759 RegexpCollectionPrettyPrinter.
2760 New function: register_pretty_printer.
2762 ** New commands "info pretty-printers", "enable pretty-printer" and
2763 "disable pretty-printer" have been added.
2765 ** gdb.parameter("directories") is now available.
2767 ** New function gdb.newest_frame returns the newest frame in the
2770 ** The gdb.InferiorThread class has a new "name" attribute. This
2771 holds the thread's name.
2773 ** Python Support for Inferior events.
2774 Python scripts can add observers to be notified of events
2775 occurring in the process being debugged.
2776 The following events are currently supported:
2777 - gdb.events.cont Continue event.
2778 - gdb.events.exited Inferior exited event.
2779 - gdb.events.stop Signal received, and Breakpoint hit events.
2783 ** GDB now puts template parameters in scope when debugging in an
2784 instantiation. For example, if you have:
2786 template<int X> int func (void) { return X; }
2788 then if you step into func<5>, "print X" will show "5". This
2789 feature requires proper debuginfo support from the compiler; it
2790 was added to GCC 4.5.
2792 ** The motion commands "next", "finish", "until", and "advance" now
2793 work better when exceptions are thrown. In particular, GDB will
2794 no longer lose control of the inferior; instead, the GDB will
2795 stop the inferior at the point at which the exception is caught.
2796 This functionality requires a change in the exception handling
2797 code that was introduced in GCC 4.5.
2799 * GDB now follows GCC's rules on accessing volatile objects when
2800 reading or writing target state during expression evaluation.
2801 One notable difference to prior behavior is that "print x = 0"
2802 no longer generates a read of x; the value of the assignment is
2803 now always taken directly from the value being assigned.
2805 * GDB now has some support for using labels in the program's source in
2806 linespecs. For instance, you can use "advance label" to continue
2807 execution to a label.
2809 * GDB now has support for reading and writing a new .gdb_index
2810 section. This section holds a fast index of DWARF debugging
2811 information and can be used to greatly speed up GDB startup and
2812 operation. See the documentation for `save gdb-index' for details.
2814 * The "watch" command now accepts an optional "-location" argument.
2815 When used, this causes GDB to watch the memory referred to by the
2816 expression. Such a watchpoint is never deleted due to it going out
2819 * GDB now supports thread debugging of core dumps on GNU/Linux.
2821 GDB now activates thread debugging using the libthread_db library
2822 when debugging GNU/Linux core dumps, similarly to when debugging
2823 live processes. As a result, when debugging a core dump file, GDB
2824 is now able to display pthread_t ids of threads. For example, "info
2825 threads" shows the same output as when debugging the process when it
2826 was live. In earlier releases, you'd see something like this:
2829 * 1 LWP 6780 main () at main.c:10
2831 While now you see this:
2834 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2836 It is also now possible to inspect TLS variables when debugging core
2839 When debugging a core dump generated on a machine other than the one
2840 used to run GDB, you may need to point GDB at the correct
2841 libthread_db library with the "set libthread-db-search-path"
2842 command. See the user manual for more details on this command.
2844 * When natively debugging programs on PowerPC BookE processors running
2845 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2846 which stop execution of the inferior whenever it executes an instruction
2847 at any address within the specified range. See the "PowerPC Embedded"
2848 section in the user manual for more details.
2850 * New features in the GDB remote stub, GDBserver
2852 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2853 and i686 LynxOS (version 5.x).
2855 ** GDBserver is now supported on Blackfin Linux.
2857 * New native configurations
2859 ia64 HP-UX ia64-*-hpux*
2863 Analog Devices, Inc. Blackfin Processor bfin-*
2865 * Ada task switching is now supported on sparc-elf targets when
2866 debugging a program using the Ravenscar Profile. For more information,
2867 see the "Tasking Support when using the Ravenscar Profile" section
2868 in the GDB user manual.
2870 * Guile support was removed.
2872 * New features in the GNU simulator
2874 ** The --map-info flag lists all known core mappings.
2876 ** CFI flashes may be simulated via the "cfi" device.
2878 *** Changes in GDB 7.2
2880 * Shared library support for remote targets by default
2882 When GDB is configured for a generic, non-OS specific target, like
2883 for example, --target=arm-eabi or one of the many *-*-elf targets,
2884 GDB now queries remote stubs for loaded shared libraries using the
2885 `qXfer:libraries:read' packet. Previously, shared library support
2886 was always disabled for such configurations.
2890 ** Argument Dependent Lookup (ADL)
2892 In C++ ADL lookup directs function search to the namespaces of its
2893 arguments even if the namespace has not been imported.
2903 Here the compiler will search for `foo' in the namespace of 'b'
2904 and find A::foo. GDB now supports this. This construct is commonly
2905 used in the Standard Template Library for operators.
2907 ** Improved User Defined Operator Support
2909 In addition to member operators, GDB now supports lookup of operators
2910 defined in a namespace and imported with a `using' directive, operators
2911 defined in the global scope, operators imported implicitly from an
2912 anonymous namespace, and the ADL operators mentioned in the previous
2914 GDB now also supports proper overload resolution for all the previously
2915 mentioned flavors of operators.
2917 ** static const class members
2919 Printing of static const class members that are initialized in the
2920 class definition has been fixed.
2922 * Windows Thread Information Block access.
2924 On Windows targets, GDB now supports displaying the Windows Thread
2925 Information Block (TIB) structure. This structure is visible either
2926 by using the new command `info w32 thread-information-block' or, by
2927 dereferencing the new convenience variable named `$_tlb', a
2928 thread-specific pointer to the TIB. This feature is also supported
2929 when remote debugging using GDBserver.
2931 * Static tracepoints
2933 Static tracepoints are calls in the user program into a tracing
2934 library. One such library is a port of the LTTng kernel tracer to
2935 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2936 When debugging with GDBserver, GDB now supports combining the GDB
2937 tracepoint machinery with such libraries. For example: the user can
2938 use GDB to probe a static tracepoint marker (a call from the user
2939 program into the tracing library) with the new "strace" command (see
2940 "New commands" below). This creates a "static tracepoint" in the
2941 breakpoint list, that can be manipulated with the same feature set
2942 as fast and regular tracepoints. E.g., collect registers, local and
2943 global variables, collect trace state variables, and define
2944 tracepoint conditions. In addition, the user can collect extra
2945 static tracepoint marker specific data, by collecting the new
2946 $_sdata internal variable. When analyzing the trace buffer, you can
2947 inspect $_sdata like any other variable available to GDB. For more
2948 information, see the "Tracepoints" chapter in GDB user manual. New
2949 remote packets have been defined to support static tracepoints, see
2950 the "New remote packets" section below.
2952 * Better reconstruction of tracepoints after disconnected tracing
2954 GDB will attempt to download the original source form of tracepoint
2955 definitions when starting a trace run, and then will upload these
2956 upon reconnection to the target, resulting in a more accurate
2957 reconstruction of the tracepoints that are in use on the target.
2961 You can now exercise direct control over the ways that GDB can
2962 affect your program. For instance, you can disallow the setting of
2963 breakpoints, so that the program can run continuously (assuming
2964 non-stop mode). In addition, the "observer" variable is available
2965 to switch all of the different controls; in observer mode, GDB
2966 cannot affect the target's behavior at all, which is useful for
2967 tasks like diagnosing live systems in the field.
2969 * The new convenience variable $_thread holds the number of the
2972 * New remote packets
2976 Return the address of the Windows Thread Information Block of a given thread.
2980 In response to several of the tracepoint packets, the target may now
2981 also respond with a number of intermediate `qRelocInsn' request
2982 packets before the final result packet, to have GDB handle
2983 relocating an instruction to execute at a different address. This
2984 is particularly useful for stubs that support fast tracepoints. GDB
2985 reports support for this feature in the qSupported packet.
2989 List static tracepoint markers in the target program.
2993 List static tracepoint markers at a given address in the target
2996 qXfer:statictrace:read
2998 Read the static trace data collected (by a `collect $_sdata'
2999 tracepoint action). The remote stub reports support for this packet
3000 to gdb's qSupported query.
3004 Send the current settings of GDB's permission flags.
3008 Send part of the source (textual) form of a tracepoint definition,
3009 which includes location, conditional, and action list.
3011 * The source command now accepts a -s option to force searching for the
3012 script in the source search path even if the script name specifies
3015 * New features in the GDB remote stub, GDBserver
3017 - GDBserver now support tracepoints (including fast tracepoints, and
3018 static tracepoints). The feature is currently supported by the
3019 i386-linux and amd64-linux builds. See the "Tracepoints support
3020 in gdbserver" section in the manual for more information.
3022 GDBserver JIT compiles the tracepoint's conditional agent
3023 expression bytecode into native code whenever possible for low
3024 overhead dynamic tracepoints conditionals. For such tracepoints,
3025 an expression that examines program state is evaluated when the
3026 tracepoint is reached, in order to determine whether to capture
3027 trace data. If the condition is simple and false, processing the
3028 tracepoint finishes very quickly and no data is gathered.
3030 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3031 for static tracepoints support.
3033 - GDBserver now supports x86_64 Windows 64-bit debugging.
3035 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3036 it understands register description.
3038 * The --batch flag now disables pagination and queries.
3040 * X86 general purpose registers
3042 GDB now supports reading/writing byte, word and double-word x86
3043 general purpose registers directly. This means you can use, say,
3044 $ah or $ax to refer, respectively, to the byte register AH and
3045 16-bit word register AX that are actually portions of the 32-bit
3046 register EAX or 64-bit register RAX.
3048 * The `commands' command now accepts a range of breakpoints to modify.
3049 A plain `commands' following a command that creates multiple
3050 breakpoints affects all the breakpoints set by that command. This
3051 applies to breakpoints set by `rbreak', and also applies when a
3052 single `break' command creates multiple breakpoints (e.g.,
3053 breakpoints on overloaded c++ functions).
3055 * The `rbreak' command now accepts a filename specification as part of
3056 its argument, limiting the functions selected by the regex to those
3057 in the specified file.
3059 * Support for remote debugging Windows and SymbianOS shared libraries
3060 from Unix hosts has been improved. Non Windows GDB builds now can
3061 understand target reported file names that follow MS-DOS based file
3062 system semantics, such as file names that include drive letters and
3063 use the backslash character as directory separator. This makes it
3064 possible to transparently use the "set sysroot" and "set
3065 solib-search-path" on Unix hosts to point as host copies of the
3066 target's shared libraries. See the new command "set
3067 target-file-system-kind" described below, and the "Commands to
3068 specify files" section in the user manual for more information.
3072 eval template, expressions...
3073 Convert the values of one or more expressions under the control
3074 of the string template to a command line, and call it.
3076 set target-file-system-kind unix|dos-based|auto
3077 show target-file-system-kind
3078 Set or show the assumed file system kind for target reported file
3081 save breakpoints <filename>
3082 Save all current breakpoint definitions to a file suitable for use
3083 in a later debugging session. To read the saved breakpoint
3084 definitions, use the `source' command.
3086 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3089 info static-tracepoint-markers
3090 Display information about static tracepoint markers in the target.
3092 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3093 Define a static tracepoint by probing a marker at the given
3094 function, line, address, or marker ID.
3098 Enable and disable observer mode.
3100 set may-write-registers on|off
3101 set may-write-memory on|off
3102 set may-insert-breakpoints on|off
3103 set may-insert-tracepoints on|off
3104 set may-insert-fast-tracepoints on|off
3105 set may-interrupt on|off
3106 Set individual permissions for GDB effects on the target. Note that
3107 some of these settings can have undesirable or surprising
3108 consequences, particularly when changed in the middle of a session.
3109 For instance, disabling the writing of memory can prevent
3110 breakpoints from being inserted, cause single-stepping to fail, or
3111 even crash your program, if you disable after breakpoints have been
3112 inserted. However, GDB should not crash.
3114 set record memory-query on|off
3115 show record memory-query
3116 Control whether to stop the inferior if memory changes caused
3117 by an instruction cannot be recorded.
3122 The disassemble command now supports "start,+length" form of two arguments.
3126 ** GDB now provides a new directory location, called the python directory,
3127 where Python scripts written for GDB can be installed. The location
3128 of that directory is <data-directory>/python, where <data-directory>
3129 is the GDB data directory. For more details, see section `Scripting
3130 GDB using Python' in the manual.
3132 ** The GDB Python API now has access to breakpoints, symbols, symbol
3133 tables, program spaces, inferiors, threads and frame's code blocks.
3134 Additionally, GDB Parameters can now be created from the API, and
3135 manipulated via set/show in the CLI.
3137 ** New functions gdb.target_charset, gdb.target_wide_charset,
3138 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3140 ** New exception gdb.GdbError.
3142 ** Pretty-printers are now also looked up in the current program space.
3144 ** Pretty-printers can now be individually enabled and disabled.
3146 ** GDB now looks for names of Python scripts to auto-load in a
3147 special section named `.debug_gdb_scripts', in addition to looking
3148 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3150 * Tracepoint actions were unified with breakpoint commands. In particular,
3151 there are no longer differences in "info break" output for breakpoints and
3152 tracepoints and the "commands" command can be used for both tracepoints and
3153 regular breakpoints.
3157 ARM Symbian arm*-*-symbianelf*
3159 * D language support.
3160 GDB now supports debugging programs written in the D programming
3163 * GDB now supports the extended ptrace interface for PowerPC which is
3164 available since Linux kernel version 2.6.34. This automatically enables
3165 any hardware breakpoints and additional hardware watchpoints available in
3166 the processor. The old ptrace interface exposes just one hardware
3167 watchpoint and no hardware breakpoints.
3169 * GDB is now able to use the Data Value Compare (DVC) register available on
3170 embedded PowerPC processors to implement in hardware simple watchpoint
3171 conditions of the form:
3173 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3175 This works in native GDB running on Linux kernels with the extended ptrace
3176 interface mentioned above.
3178 *** Changes in GDB 7.1
3182 ** Namespace Support
3184 GDB now supports importing of namespaces in C++. This enables the
3185 user to inspect variables from imported namespaces. Support for
3186 namepace aliasing has also been added. So, if a namespace is
3187 aliased in the current scope (e.g. namepace C=A; ) the user can
3188 print variables using the alias (e.g. (gdb) print C::x).
3192 All known bugs relating to the printing of virtual base class were
3193 fixed. It is now possible to call overloaded static methods using a
3198 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3199 and reinterpret_cast<> are now handled by the C++ expression parser.
3203 Xilinx MicroBlaze microblaze-*-*
3208 Xilinx MicroBlaze microblaze
3211 * Multi-program debugging.
3213 GDB now has support for multi-program (a.k.a. multi-executable or
3214 multi-exec) debugging. This allows for debugging multiple inferiors
3215 simultaneously each running a different program under the same GDB
3216 session. See "Debugging Multiple Inferiors and Programs" in the
3217 manual for more information. This implied some user visible changes
3218 in the multi-inferior support. For example, "info inferiors" now
3219 lists inferiors that are not running yet or that have exited
3220 already. See also "New commands" and "New options" below.
3222 * New tracing features
3224 GDB's tracepoint facility now includes several new features:
3226 ** Trace state variables
3228 GDB tracepoints now include support for trace state variables, which
3229 are variables managed by the target agent during a tracing
3230 experiment. They are useful for tracepoints that trigger each
3231 other, so for instance one tracepoint can count hits in a variable,
3232 and then a second tracepoint has a condition that is true when the
3233 count reaches a particular value. Trace state variables share the
3234 $-syntax of GDB convenience variables, and can appear in both
3235 tracepoint actions and condition expressions. Use the "tvariable"
3236 command to create, and "info tvariables" to view; see "Trace State
3237 Variables" in the manual for more detail.
3241 GDB now includes an option for defining fast tracepoints, which
3242 targets may implement more efficiently, such as by installing a jump
3243 into the target agent rather than a trap instruction. The resulting
3244 speedup can be by two orders of magnitude or more, although the
3245 tradeoff is that some program locations on some target architectures
3246 might not allow fast tracepoint installation, for instance if the
3247 instruction to be replaced is shorter than the jump. To request a
3248 fast tracepoint, use the "ftrace" command, with syntax identical to
3249 the regular trace command.
3251 ** Disconnected tracing
3253 It is now possible to detach GDB from the target while it is running
3254 a trace experiment, then reconnect later to see how the experiment
3255 is going. In addition, a new variable disconnected-tracing lets you
3256 tell the target agent whether to continue running a trace if the
3257 connection is lost unexpectedly.
3261 GDB now has the ability to save the trace buffer into a file, and
3262 then use that file as a target, similarly to you can do with
3263 corefiles. You can select trace frames, print data that was
3264 collected in them, and use tstatus to display the state of the
3265 tracing run at the moment that it was saved. To create a trace
3266 file, use "tsave <filename>", and to use it, do "target tfile
3269 ** Circular trace buffer
3271 You can ask the target agent to handle the trace buffer as a
3272 circular buffer, discarding the oldest trace frames to make room for
3273 newer ones, by setting circular-trace-buffer to on. This feature may
3274 not be available for all target agents.
3279 The disassemble command, when invoked with two arguments, now requires
3280 the arguments to be comma-separated.
3283 The info variables command now displays variable definitions. Files
3284 which only declare a variable are not shown.
3287 The source command is now capable of sourcing Python scripts.
3288 This feature is dependent on the debugger being build with Python
3291 Related to this enhancement is also the introduction of a new command
3292 "set script-extension" (see below).
3294 * New commands (for set/show, see "New options" below)
3296 record save [<FILENAME>]
3297 Save a file (in core file format) containing the process record
3298 execution log for replay debugging at a later time.
3300 record restore <FILENAME>
3301 Restore the process record execution log that was saved at an
3302 earlier time, for replay debugging.
3304 add-inferior [-copies <N>] [-exec <FILENAME>]
3307 clone-inferior [-copies <N>] [ID]
3308 Make a new inferior ready to execute the same program another
3309 inferior has loaded.
3314 maint info program-spaces
3315 List the program spaces loaded into GDB.
3317 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3318 show remote interrupt-sequence
3319 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3320 as the sequence to the remote target in order to interrupt the execution.
3321 Ctrl-C is a default. Some system prefers BREAK which is high level of
3322 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3323 Magic SysRq g. It is BREAK signal and character 'g'.
3325 set remote interrupt-on-connect [on | off]
3326 show remote interrupt-on-connect
3327 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3328 remote target when gdb connects to it. This is needed when you debug
3331 set remotebreak [on | off]
3333 Deprecated. Use "set/show remote interrupt-sequence" instead.
3335 tvariable $NAME [ = EXP ]
3336 Create or modify a trace state variable.
3339 List trace state variables and their values.
3341 delete tvariable $NAME ...
3342 Delete one or more trace state variables.
3345 Evaluate the given expressions without collecting anything into the
3346 trace buffer. (Valid in tracepoint actions only.)
3348 ftrace FN / FILE:LINE / *ADDR
3349 Define a fast tracepoint at the given function, line, or address.
3351 * New expression syntax
3353 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3354 GDB now parses 0b101010 identically with 42.
3358 set follow-exec-mode new|same
3359 show follow-exec-mode
3360 Control whether GDB reuses the same inferior across an exec call or
3361 creates a new one. This is useful to be able to restart the old
3362 executable after the inferior having done an exec call.
3364 set default-collect EXPR, ...
3365 show default-collect
3366 Define a list of expressions to be collected at each tracepoint.
3367 This is a useful way to ensure essential items are not overlooked,
3368 such as registers or a critical global variable.
3370 set disconnected-tracing
3371 show disconnected-tracing
3372 If set to 1, the target is instructed to continue tracing if it
3373 loses its connection to GDB. If 0, the target is to stop tracing
3376 set circular-trace-buffer
3377 show circular-trace-buffer
3378 If set to on, the target is instructed to use a circular trace buffer
3379 and discard the oldest trace frames instead of stopping the trace due
3380 to a full trace buffer. If set to off, the trace stops when the buffer
3381 fills up. Some targets may not support this.
3383 set script-extension off|soft|strict
3384 show script-extension
3385 If set to "off", the debugger does not perform any script language
3386 recognition, and all sourced files are assumed to be GDB scripts.
3387 If set to "soft" (the default), files are sourced according to
3388 filename extension, falling back to GDB scripts if the first
3390 If set to "strict", files are sourced according to filename extension.
3392 set ada trust-PAD-over-XVS on|off
3393 show ada trust-PAD-over-XVS
3394 If off, activate a workaround against a bug in the debugging information
3395 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3396 the GCC sources for more information about the GNAT encoding and
3397 PAD types in particular). It is always safe to set this option to
3398 off, but this introduces a slight performance penalty. The default
3401 * Python API Improvements
3403 ** GDB provides the new class gdb.LazyString. This is useful in
3404 some pretty-printing cases. The new method gdb.Value.lazy_string
3405 provides a simple way to create objects of this type.
3407 ** The fields returned by gdb.Type.fields now have an
3408 `is_base_class' attribute.
3410 ** The new method gdb.Type.range returns the range of an array type.
3412 ** The new method gdb.parse_and_eval can be used to parse and
3413 evaluate an expression.
3415 * New remote packets
3418 Define a trace state variable.
3421 Get the current value of a trace state variable.
3424 Set desired tracing behavior upon disconnection.
3427 Set the trace buffer to be linear or circular.
3430 Get data about the tracepoints currently in use.
3434 Process record now works correctly with hardware watchpoints.
3436 Multiple bug fixes have been made to the mips-irix port, making it
3437 much more reliable. In particular:
3438 - Debugging threaded applications is now possible again. Previously,
3439 GDB would hang while starting the program, or while waiting for
3440 the program to stop at a breakpoint.
3441 - Attaching to a running process no longer hangs.
3442 - An error occurring while loading a core file has been fixed.
3443 - Changing the value of the PC register now works again. This fixes
3444 problems observed when using the "jump" command, or when calling
3445 a function from GDB, or even when assigning a new value to $pc.
3446 - With the "finish" and "return" commands, the return value for functions
3447 returning a small array is now correctly printed.
3448 - It is now possible to break on shared library code which gets executed
3449 during a shared library init phase (code executed while executing
3450 their .init section). Previously, the breakpoint would have no effect.
3451 - GDB is now able to backtrace through the signal handler for
3452 non-threaded programs.
3454 PIE (Position Independent Executable) programs debugging is now supported.
3455 This includes debugging execution of PIC (Position Independent Code) shared
3456 libraries although for that, it should be possible to run such libraries as an
3459 *** Changes in GDB 7.0
3461 * GDB now has an interface for JIT compilation. Applications that
3462 dynamically generate code can create symbol files in memory and register
3463 them with GDB. For users, the feature should work transparently, and
3464 for JIT developers, the interface is documented in the GDB manual in the
3465 "JIT Compilation Interface" chapter.
3467 * Tracepoints may now be conditional. The syntax is as for
3468 breakpoints; either an "if" clause appended to the "trace" command,
3469 or the "condition" command is available. GDB sends the condition to
3470 the target for evaluation using the same bytecode format as is used
3471 for tracepoint actions.
3473 * The disassemble command now supports: an optional /r modifier, print the
3474 raw instructions in hex as well as in symbolic form, and an optional /m
3475 modifier to print mixed source+assembly.
3477 * Process record and replay
3479 In a architecture environment that supports ``process record and
3480 replay'', ``process record and replay'' target can record a log of
3481 the process execution, and replay it with both forward and reverse
3484 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3485 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3486 set execution-direction {forward|reverse}, for targets that support
3489 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3490 feature is available with a native GDB running on kernel version
3493 * GDB now has support for multi-byte and wide character sets on the
3494 target. Strings whose character type is wchar_t, char16_t, or
3495 char32_t are now correctly printed. GDB supports wide- and unicode-
3496 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3497 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3498 `printf'. This feature requires iconv to work properly; if your
3499 system does not have a working iconv, GDB can use GNU libiconv. See
3500 the installation instructions for more information.
3502 * GDB now supports automatic retrieval of shared library files from
3503 remote targets. To use this feature, specify a system root that begins
3504 with the `remote:' prefix, either via the `set sysroot' command or via
3505 the `--with-sysroot' configure-time option.
3507 * "info sharedlibrary" now takes an optional regex of libraries to show,
3508 and it now reports if a shared library has no debugging information.
3510 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3511 now complete on file names.
3513 * When completing in expressions, gdb will attempt to limit
3514 completions to allowable structure or union fields, where appropriate.
3515 For instance, consider:
3517 # struct example { int f1; double f2; };
3518 # struct example variable;
3521 If the user types TAB at the end of this command line, the available
3522 completions will be "f1" and "f2".
3524 * Inlined functions are now supported. They show up in backtraces, and
3525 the "step", "next", and "finish" commands handle them automatically.
3527 * GDB now supports the token-splicing (##) and stringification (#)
3528 operators when expanding macros. It also supports variable-arity
3531 * GDB now supports inspecting extra signal information, exported by
3532 the new $_siginfo convenience variable. The feature is currently
3533 implemented on linux ARM, i386 and amd64.
3535 * GDB can now display the VFP floating point registers and NEON vector
3536 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3537 can provide these registers (requires Linux 2.6.30 or later). Remote
3538 and simulator targets may also provide them.
3540 * New remote packets
3543 Search memory for a sequence of bytes.
3546 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3547 operation over reliable transport links. Use of this packet is
3548 controlled by the `set remote noack-packet' command.
3551 Kill the process with the specified process ID. Use this in preference
3552 to `k' when multiprocess protocol extensions are supported.
3555 Obtains additional operating system information
3559 Read or write additional signal information.
3561 * Removed remote protocol undocumented extension
3563 An undocumented extension to the remote protocol's `S' stop reply
3564 packet that permited the stub to pass a process id was removed.
3565 Remote servers should use the `T' stop reply packet instead.
3567 * GDB now supports multiple function calling conventions according to the
3568 DWARF-2 DW_AT_calling_convention function attribute.
3570 * The SH target utilizes the aforementioned change to distinguish between gcc
3571 and Renesas calling convention. It also adds the new CLI commands
3572 `set/show sh calling-convention'.
3574 * GDB can now read compressed debug sections, as produced by GNU gold
3575 with the --compress-debug-sections=zlib flag.
3577 * 64-bit core files are now supported on AIX.
3579 * Thread switching is now supported on Tru64.
3581 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3582 which will be allocated using malloc later in program execution.
3584 * The qXfer:libraries:read remote procotol packet now allows passing a
3585 list of section offsets.
3587 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3588 conditions handling signals delivered during attach or thread creation
3589 have also been fixed.
3591 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3592 From the user's standpoint, all unqualified instances of True and False
3593 are treated as the standard definitions, regardless of context.
3595 * GDB now parses C++ symbol and type names more flexibly. For
3598 template<typename T> class C { };
3601 GDB will now correctly handle all of:
3603 ptype C<char const *>
3604 ptype C<char const*>
3605 ptype C<const char *>
3606 ptype C<const char*>
3608 * New features in the GDB remote stub, gdbserver
3610 - The "--wrapper" command-line argument tells gdbserver to use a
3611 wrapper program to launch programs for debugging.
3613 - On PowerPC and S/390 targets, it is now possible to use a single
3614 gdbserver executable to debug both 32-bit and 64-bit programs.
3615 (This requires gdbserver itself to be built as a 64-bit executable.)
3617 - gdbserver uses the new noack protocol mode for TCP connections to
3618 reduce communications latency, if also supported and enabled in GDB.
3620 - Support for the sparc64-linux-gnu target is now included in
3623 - The amd64-linux build of gdbserver now supports debugging both
3624 32-bit and 64-bit programs.
3626 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3627 now support hardware watchpoints, and will use them automatically
3632 GDB now has support for scripting using Python. Whether this is
3633 available is determined at configure time.
3635 New GDB commands can now be written in Python.
3637 * Ada tasking support
3639 Ada tasks can now be inspected in GDB. The following commands have
3643 Print the list of Ada tasks.
3645 Print detailed information about task number N.
3647 Print the task number of the current task.
3649 Switch the context of debugging to task number N.
3651 * Support for user-defined prefixed commands. The "define" command can
3652 add new commands to existing prefixes, e.g. "target".
3654 * Multi-inferior, multi-process debugging.
3656 GDB now has generalized support for multi-inferior debugging. See
3657 "Debugging Multiple Inferiors" in the manual for more information.
3658 Although availability still depends on target support, the command
3659 set is more uniform now. The GNU/Linux specific multi-forks support
3660 has been migrated to this new framework. This implied some user
3661 visible changes; see "New commands" and also "Removed commands"
3664 * Target descriptions can now describe the target OS ABI. See the
3665 "Target Description Format" section in the user manual for more
3668 * Target descriptions can now describe "compatible" architectures
3669 to indicate that the target can execute applications for a different
3670 architecture in addition to those for the main target architecture.
3671 See the "Target Description Format" section in the user manual for
3674 * Multi-architecture debugging.
3676 GDB now includes general supports for debugging applications on
3677 hybrid systems that use more than one single processor architecture
3678 at the same time. Each such hybrid architecture still requires
3679 specific support to be added. The only hybrid architecture supported
3680 in this version of GDB is the Cell Broadband Engine.
3682 * GDB now supports integrated debugging of Cell/B.E. applications that
3683 use both the PPU and SPU architectures. To enable support for hybrid
3684 Cell/B.E. debugging, you need to configure GDB to support both the
3685 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3686 --enable-targets configure option.
3688 * Non-stop mode debugging.
3690 For some targets, GDB now supports an optional mode of operation in
3691 which you can examine stopped threads while other threads continue
3692 to execute freely. This is referred to as non-stop mode, with the
3693 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3694 section in the user manual for more information.
3696 To be able to support remote non-stop debugging, a remote stub needs
3697 to implement the non-stop mode remote protocol extensions, as
3698 described in the "Remote Non-Stop" section of the user manual. The
3699 GDB remote stub, gdbserver, has been adjusted to support these
3700 extensions on linux targets.
3702 * New commands (for set/show, see "New options" below)
3704 catch syscall [NAME(S) | NUMBER(S)]
3705 Catch system calls. Arguments, which should be names of system
3706 calls or their numbers, mean catch only those syscalls. Without
3707 arguments, every syscall will be caught. When the inferior issues
3708 any of the specified syscalls, GDB will stop and announce the system
3709 call, both when it is called and when its call returns. This
3710 feature is currently available with a native GDB running on the
3711 Linux Kernel, under the following architectures: x86, x86_64,
3712 PowerPC and PowerPC64.
3714 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3716 Search memory for a sequence of bytes.
3718 maint set python print-stack
3719 maint show python print-stack
3720 Show a stack trace when an error is encountered in a Python script.
3723 Invoke CODE by passing it to the Python interpreter.
3728 These allow macros to be defined, undefined, and listed
3732 Show operating system information about processes.
3735 List the inferiors currently under GDB's control.
3738 Switch focus to inferior number NUM.
3741 Detach from inferior number NUM.
3744 Kill inferior number NUM.
3748 set spu stop-on-load
3749 show spu stop-on-load
3750 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3752 set spu auto-flush-cache
3753 show spu auto-flush-cache
3754 Control whether to automatically flush the software-managed cache
3755 during Cell/B.E. debugging.
3757 set sh calling-convention
3758 show sh calling-convention
3759 Control the calling convention used when calling SH target functions.
3762 show debug timestamp
3763 Control display of timestamps with GDB debugging output.
3765 set disassemble-next-line
3766 show disassemble-next-line
3767 Control display of disassembled source lines or instructions when
3770 set remote noack-packet
3771 show remote noack-packet
3772 Set/show the use of remote protocol QStartNoAckMode packet. See above
3773 under "New remote packets."
3775 set remote query-attached-packet
3776 show remote query-attached-packet
3777 Control use of remote protocol `qAttached' (query-attached) packet.
3779 set remote read-siginfo-object
3780 show remote read-siginfo-object
3781 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3784 set remote write-siginfo-object
3785 show remote write-siginfo-object
3786 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3789 set remote reverse-continue
3790 show remote reverse-continue
3791 Control use of remote protocol 'bc' (reverse-continue) packet.
3793 set remote reverse-step
3794 show remote reverse-step
3795 Control use of remote protocol 'bs' (reverse-step) packet.
3797 set displaced-stepping
3798 show displaced-stepping
3799 Control displaced stepping mode. Displaced stepping is a way to
3800 single-step over breakpoints without removing them from the debuggee.
3801 Also known as "out-of-line single-stepping".
3804 show debug displaced
3805 Control display of debugging info for displaced stepping.
3807 maint set internal-error
3808 maint show internal-error
3809 Control what GDB does when an internal error is detected.
3811 maint set internal-warning
3812 maint show internal-warning
3813 Control what GDB does when an internal warning is detected.
3818 Use a wrapper program to launch programs for debugging.
3820 set multiple-symbols (all|ask|cancel)
3821 show multiple-symbols
3822 The value of this variable can be changed to adjust the debugger behavior
3823 when an expression or a breakpoint location contains an ambiguous symbol
3824 name (an overloaded function name, for instance).
3826 set breakpoint always-inserted
3827 show breakpoint always-inserted
3828 Keep breakpoints always inserted in the target, as opposed to inserting
3829 them when resuming the target, and removing them when the target stops.
3830 This option can improve debugger performance on slow remote targets.
3832 set arm fallback-mode (arm|thumb|auto)
3833 show arm fallback-mode
3834 set arm force-mode (arm|thumb|auto)
3836 These commands control how ARM GDB determines whether instructions
3837 are ARM or Thumb. The default for both settings is auto, which uses
3838 the current CPSR value for instructions without symbols; previous
3839 versions of GDB behaved as if "set arm fallback-mode arm".
3841 set disable-randomization
3842 show disable-randomization
3843 Standalone programs run with the virtual address space randomization enabled
3844 by default on some platforms. This option keeps the addresses stable across
3845 multiple debugging sessions.
3849 Control whether other threads are stopped or not when some thread hits
3854 Requests that asynchronous execution is enabled in the target, if available.
3855 In this case, it's possible to resume target in the background, and interact
3856 with GDB while the target is running. "show target-async" displays the
3857 current state of asynchronous execution of the target.
3859 set target-wide-charset
3860 show target-wide-charset
3861 The target-wide-charset is the name of the character set that GDB
3862 uses when printing characters whose type is wchar_t.
3864 set tcp auto-retry (on|off)
3866 set tcp connect-timeout
3867 show tcp connect-timeout
3868 These commands allow GDB to retry failed TCP connections to a remote stub
3869 with a specified timeout period; this is useful if the stub is launched
3870 in parallel with GDB but may not be ready to accept connections immediately.
3872 set libthread-db-search-path
3873 show libthread-db-search-path
3874 Control list of directories which GDB will search for appropriate
3877 set schedule-multiple (on|off)
3878 show schedule-multiple
3879 Allow GDB to resume all threads of all processes or only threads of
3880 the current process.
3884 Use more aggressive caching for accesses to the stack. This improves
3885 performance of remote debugging (particularly backtraces) without
3886 affecting correctness.
3888 set interactive-mode (on|off|auto)
3889 show interactive-mode
3890 Control whether GDB runs in interactive mode (on) or not (off).
3891 When in interactive mode, GDB waits for the user to answer all
3892 queries. Otherwise, GDB does not wait and assumes the default
3893 answer. When set to auto (the default), GDB determines which
3894 mode to use based on the stdin settings.
3899 For program forks, this is replaced by the new more generic `info
3900 inferiors' command. To list checkpoints, you can still use the
3901 `info checkpoints' command, which was an alias for the `info forks'
3905 Replaced by the new `inferior' command. To switch between
3906 checkpoints, you can still use the `restart' command, which was an
3907 alias for the `fork' command.
3910 This is removed, since some targets don't have a notion of
3911 processes. To switch between processes, you can still use the
3912 `inferior' command using GDB's own inferior number.
3915 For program forks, this is replaced by the new more generic `kill
3916 inferior' command. To delete a checkpoint, you can still use the
3917 `delete checkpoint' command, which was an alias for the `delete
3921 For program forks, this is replaced by the new more generic `detach
3922 inferior' command. To detach a checkpoint, you can still use the
3923 `detach checkpoint' command, which was an alias for the `detach
3926 * New native configurations
3928 x86/x86_64 Darwin i[34567]86-*-darwin*
3930 x86_64 MinGW x86_64-*-mingw*
3934 Lattice Mico32 lm32-*
3935 x86 DICOS i[34567]86-*-dicos*
3936 x86_64 DICOS x86_64-*-dicos*
3939 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3940 (mingw32ce) debugging.
3946 These commands were actually not implemented on any target.
3948 *** Changes in GDB 6.8
3950 * New native configurations
3952 NetBSD/hppa hppa*-*netbsd*
3953 Xtensa GNU/Linux xtensa*-*-linux*
3957 NetBSD/hppa hppa*-*-netbsd*
3958 Xtensa GNU/Lunux xtensa*-*-linux*
3960 * Change in command line behavior -- corefiles vs. process ids.
3962 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3963 attaching to process NUMBER fails, GDB no longer attempts to open a
3964 core file named NUMBER. Attaching to a program using the -c option
3965 is no longer supported. Instead, use the '-p' or '--pid' options.
3967 * GDB can now be built as a native debugger for debugging Windows x86
3968 (mingw32) Portable Executable (PE) programs.
3970 * Pending breakpoints no longer change their number when their address
3973 * GDB now supports breakpoints with multiple locations,
3974 including breakpoints on C++ constructors, inside C++ templates,
3975 and in inlined functions.
3977 * GDB's ability to debug optimized code has been improved. GDB more
3978 accurately identifies function bodies and lexical blocks that occupy
3979 more than one contiguous range of addresses.
3981 * Target descriptions can now describe registers for PowerPC.
3983 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3984 registers on PowerPC targets.
3986 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3987 targets even when the libthread_db library is not available.
3989 * The GDB remote stub, gdbserver, now supports the new file transfer
3990 commands (remote put, remote get, and remote delete).
3992 * The GDB remote stub, gdbserver, now supports run and attach in
3993 extended-remote mode.
3995 * hppa*64*-*-hpux11* target broken
3996 The debugger is unable to start a program and fails with the following
3997 error: "Error trying to get information about dynamic linker".
3998 The gdb-6.7 release is also affected.
4000 * GDB now supports the --enable-targets= configure option to allow
4001 building a single GDB executable that supports multiple remote
4002 target architectures.
4004 * GDB now supports debugging C and C++ programs which use the
4005 Decimal Floating Point extension. In addition, the PowerPC target
4006 now has a set of pseudo-registers to inspect decimal float values
4007 stored in two consecutive float registers.
4009 * The -break-insert MI command can optionally create pending
4012 * Improved support for debugging Ada
4013 Many improvements to the Ada language support have been made. These
4015 - Better support for Ada2005 interface types
4016 - Improved handling of arrays and slices in general
4017 - Better support for Taft-amendment types
4018 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4020 - Improved command completion in Ada
4023 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4028 set print frame-arguments (all|scalars|none)
4029 show print frame-arguments
4030 The value of this variable can be changed to control which argument
4031 values should be printed by the debugger when displaying a frame.
4036 Transfer files to and from a remote target, and delete remote files.
4043 Transfer files to and from a remote target, and delete remote files.
4045 * New remote packets
4052 Open, close, read, write, and delete files on the remote system.
4055 Attach to an existing process on the remote system, in extended-remote
4059 Run a new process on the remote system, in extended-remote mode.
4061 *** Changes in GDB 6.7
4063 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4064 bfd, libiberty and opcodes, as revealed by static analysis donated by
4065 Coverity, Inc. (http://scan.coverity.com).
4067 * When looking up multiply-defined global symbols, GDB will now prefer the
4068 symbol definition in the current shared library if it was built using the
4069 -Bsymbolic linker option.
4071 * When the Text User Interface (TUI) is not configured, GDB will now
4072 recognize the -tui command-line option and print a message that the TUI
4075 * The GDB remote stub, gdbserver, now has lower overhead for high
4076 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4078 * GDB for MIPS targets now autodetects whether a remote target provides
4079 32-bit or 64-bit register values.
4081 * Support for C++ member pointers has been improved.
4083 * GDB now understands XML target descriptions, which specify the
4084 target's overall architecture. GDB can read a description from
4085 a local file or over the remote serial protocol.
4087 * Vectors of single-byte data use a new integer type which is not
4088 automatically displayed as character or string data.
4090 * The /s format now works with the print command. It displays
4091 arrays of single-byte integers and pointers to single-byte integers
4094 * Target descriptions can now describe target-specific registers,
4095 for architectures which have implemented the support (currently
4096 only ARM, M68K, and MIPS).
4098 * GDB and the GDB remote stub, gdbserver, now support the XScale
4101 * The GDB remote stub, gdbserver, has been updated to support
4102 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4103 has been rewritten to use the standard GDB remote protocol.
4105 * GDB can now step into C++ functions which are called through thunks.
4107 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4109 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4110 layout. It also supports a TextSeg= and DataSeg= response when only
4111 segment base addresses (rather than offsets) are available.
4113 * The /i format now outputs any trailing branch delay slot instructions
4114 immediately following the last instruction within the count specified.
4116 * The GDB remote protocol "T" stop reply packet now supports a
4117 "library" response. Combined with the new "qXfer:libraries:read"
4118 packet, this response allows GDB to debug shared libraries on targets
4119 where the operating system manages the list of loaded libraries (e.g.
4120 Windows and SymbianOS).
4122 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4123 (DLLs) on Windows and Windows CE targets.
4125 * GDB now supports a faster verification that a .debug file matches its binary
4126 according to its build-id signature, if the signature is present.
4132 Enable or disable hardware flow control (RTS/CTS) on the serial port
4133 when debugging using remote targets.
4135 set mem inaccessible-by-default
4136 show mem inaccessible-by-default
4137 If the target supplies a memory map, for instance via the remote
4138 protocol's "qXfer:memory-map:read" packet, setting this variable
4139 prevents GDB from accessing memory outside the memory map. This
4140 is useful for targets with memory mapped registers or which react
4141 badly to accesses of unmapped address space.
4143 set breakpoint auto-hw
4144 show breakpoint auto-hw
4145 If the target supplies a memory map, for instance via the remote
4146 protocol's "qXfer:memory-map:read" packet, setting this variable
4147 lets GDB use hardware breakpoints automatically for memory regions
4148 where it can not use software breakpoints. This covers both the
4149 "break" command and internal breakpoints used for other commands
4150 including "next" and "finish".
4153 catch exception unhandled
4154 Stop the program execution when Ada exceptions are raised.
4157 Stop the program execution when an Ada assertion failed.
4161 Set an alternate system root for target files. This is a more
4162 general version of "set solib-absolute-prefix", which is now
4163 an alias to "set sysroot".
4166 Provide extended SPU facility status information. This set of
4167 commands is available only when debugging the Cell/B.E. SPU
4170 * New native configurations
4172 OpenBSD/sh sh*-*openbsd*
4175 unset tdesc filename
4177 Use the specified local file as an XML target description, and do
4178 not query the target for its built-in description.
4182 OpenBSD/sh sh*-*-openbsd*
4183 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4184 Toshiba Media Processor mep-elf
4186 * New remote packets
4189 Ignore the specified signals; pass them directly to the debugged program
4190 without stopping other threads or reporting them to GDB.
4192 qXfer:features:read:
4193 Read an XML target description from the target, which describes its
4198 Read or write contents of an spufs file on the target system. These
4199 packets are available only on the Cell/B.E. SPU architecture.
4201 qXfer:libraries:read:
4202 Report the loaded shared libraries. Combined with new "T" packet
4203 response, this packet allows GDB to debug shared libraries on
4204 targets where the operating system manages the list of loaded
4205 libraries (e.g. Windows and SymbianOS).
4209 Support for these obsolete configurations has been removed.
4217 i[34567]86-*-lynxos*
4218 i[34567]86-*-netware*
4219 i[34567]86-*-sco3.2v5*
4220 i[34567]86-*-sco3.2v4*
4222 i[34567]86-*-sysv4.2*
4225 i[34567]86-*-unixware2*
4226 i[34567]86-*-unixware*
4235 * Other removed features
4242 Various m68k-only ROM monitors.
4249 Various Renesas ROM monitors and debugging interfaces for SH and
4254 Support for a Macraigor serial interface to on-chip debugging.
4255 GDB does not directly support the newer parallel or USB
4260 A debug information format. The predecessor to DWARF 2 and
4261 DWARF 3, which are still supported.
4263 Support for the HP aCC compiler on HP-UX/PA-RISC
4265 SOM-encapsulated symbolic debugging information, automatic
4266 invocation of pxdb, and the aCC custom C++ ABI. This does not
4267 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4268 with aCC can still be debugged on an assembly level.
4270 MIPS ".pdr" sections
4272 A MIPS-specific format used to describe stack frame layout
4273 in debugging information.
4277 GDB could work with an older version of Guile to debug
4278 the interpreter and Scheme programs running in it.
4280 set mips stack-arg-size
4281 set mips saved-gpreg-size
4283 Use "set mips abi" to control parameter passing for MIPS.
4285 *** Changes in GDB 6.6
4290 Cell Broadband Engine SPU spu-elf
4292 * GDB can now be configured as a cross-debugger targeting native Windows
4293 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4294 running on a Windows system over TCP/IP to debug Windows programs.
4296 * The GDB remote stub, gdbserver, has been updated to support Windows and
4297 Cygwin debugging. Both single-threaded and multi-threaded programs are
4300 * The "set trust-readonly-sections" command works again. This command was
4301 broken in GDB 6.3, 6.4, and 6.5.
4303 * The "load" command now supports writing to flash memory, if the remote
4304 stub provides the required support.
4306 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4307 longer requires symbolic debug information (e.g. DWARF-2).
4312 unset substitute-path
4313 show substitute-path
4314 Manage a list of substitution rules that GDB uses to rewrite the name
4315 of the directories where the sources are located. This can be useful
4316 for instance when the sources were moved to a different location
4317 between compilation and debugging.
4321 Print each CLI command as it is executed. Each command is prefixed with
4322 a number of `+' symbols representing the nesting depth.
4323 The source command now has a `-v' option to enable the same feature.
4327 The ARM Demon monitor support (RDP protocol, "target rdp").
4329 Kernel Object Display, an embedded debugging feature which only worked with
4330 an obsolete version of Cisco IOS.
4332 The 'set download-write-size' and 'show download-write-size' commands.
4334 * New remote packets
4337 Tell a stub about GDB client features, and request remote target features.
4338 The first feature implemented is PacketSize, which allows the target to
4339 specify the size of packets it can handle - to minimize the number of
4340 packets required and improve performance when connected to a remote
4344 Fetch an OS auxilliary vector from the remote stub. This packet is a
4345 more efficient replacement for qPart:auxv:read.
4347 qXfer:memory-map:read:
4348 Fetch a memory map from the remote stub, including information about
4349 RAM, ROM, and flash memory devices.
4354 Erase and program a flash memory device.
4356 * Removed remote packets
4359 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4360 used it, and only gdbserver implemented it.
4362 *** Changes in GDB 6.5
4366 Renesas M32C/M16C m32c-elf
4368 Morpho Technologies ms1 ms1-elf
4372 init-if-undefined Initialize a convenience variable, but
4373 only if it doesn't already have a value.
4375 The following commands are presently only implemented for native GNU/Linux:
4377 checkpoint Save a snapshot of the program state.
4379 restart <n> Return the program state to a
4380 previously saved state.
4382 info checkpoints List currently saved checkpoints.
4384 delete-checkpoint <n> Delete a previously saved checkpoint.
4386 set|show detach-on-fork Tell gdb whether to detach from a newly
4387 forked process, or to keep debugging it.
4389 info forks List forks of the user program that
4390 are available to be debugged.
4392 fork <n> Switch to debugging one of several
4393 forks of the user program that are
4394 available to be debugged.
4396 delete-fork <n> Delete a fork from the list of forks
4397 that are available to be debugged (and
4398 kill the forked process).
4400 detach-fork <n> Delete a fork from the list of forks
4401 that are available to be debugged (and
4402 allow the process to continue).
4406 Morpho Technologies ms2 ms1-elf
4408 * Improved Windows host support
4410 GDB now builds as a cross debugger hosted on i686-mingw32, including
4411 native console support, and remote communications using either
4412 network sockets or serial ports.
4414 * Improved Modula-2 language support
4416 GDB can now print most types in the Modula-2 syntax. This includes:
4417 basic types, set types, record types, enumerated types, range types,
4418 pointer types and ARRAY types. Procedure var parameters are correctly
4419 printed and hexadecimal addresses and character constants are also
4420 written in the Modula-2 syntax. Best results can be obtained by using
4421 GNU Modula-2 together with the -gdwarf-2 command line option.
4425 The ARM rdi-share module.
4427 The Netware NLM debug server.
4429 *** Changes in GDB 6.4
4431 * New native configurations
4433 OpenBSD/arm arm*-*-openbsd*
4434 OpenBSD/mips64 mips64-*-openbsd*
4438 Morpho Technologies ms1 ms1-elf
4440 * New command line options
4442 --batch-silent As for --batch, but totally silent.
4443 --return-child-result The debugger will exist with the same value
4444 the child (debugged) program exited with.
4445 --eval-command COMMAND, -ex COMMAND
4446 Execute a single GDB CLI command. This may be
4447 specified multiple times and in conjunction
4448 with the --command (-x) option.
4450 * Deprecated commands removed
4452 The following commands, that were deprecated in 2000, have been
4456 set|show arm disassembly-flavor set|show arm disassembler
4457 othernames set arm disassembler
4458 set|show remotedebug set|show debug remote
4459 set|show archdebug set|show debug arch
4460 set|show eventdebug set|show debug event
4463 * New BSD user-level threads support
4465 It is now possible to debug programs using the user-level threads
4466 library on OpenBSD and FreeBSD. Currently supported (target)
4469 FreeBSD/amd64 x86_64-*-freebsd*
4470 FreeBSD/i386 i386-*-freebsd*
4471 OpenBSD/i386 i386-*-openbsd*
4473 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4474 are not yet supported.
4476 * New support for Matsushita MN10300 w/sim added
4477 (Work in progress). mn10300-elf.
4479 * REMOVED configurations and files
4481 VxWorks and the XDR protocol *-*-vxworks
4482 Motorola MCORE mcore-*-*
4483 National Semiconductor NS32000 ns32k-*-*
4485 * New "set print array-indexes" command
4487 After turning this setting "on", GDB prints the index of each element
4488 when displaying arrays. The default is "off" to preserve the previous
4491 * VAX floating point support
4493 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4495 * User-defined command support
4497 In addition to using $arg0..$arg9 for argument passing, it is now possible
4498 to use $argc to determine now many arguments have been passed. See the
4499 section on user-defined commands in the user manual for more information.
4501 *** Changes in GDB 6.3:
4503 * New command line option
4505 GDB now accepts -l followed by a number to set the timeout for remote
4508 * GDB works with GCC -feliminate-dwarf2-dups
4510 GDB now supports a more compact representation of DWARF-2 debug
4511 information using DW_FORM_ref_addr references. These are produced
4512 by GCC with the option -feliminate-dwarf2-dups and also by some
4513 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4514 to use -feliminate-dwarf2-dups.
4516 * Internationalization
4518 When supported by the host system, GDB will be built with
4519 internationalization (libintl). The task of marking up the sources is
4520 continued, we're looking forward to our first translation.
4524 Initial support for debugging programs compiled with the GNAT
4525 implementation of the Ada programming language has been integrated
4526 into GDB. In this release, support is limited to expression evaluation.
4528 * New native configurations
4530 GNU/Linux/m32r m32r-*-linux-gnu
4534 GDB's remote protocol now includes support for the 'p' packet. This
4535 packet is used to fetch individual registers from a remote inferior.
4537 * END-OF-LIFE registers[] compatibility module
4539 GDB's internal register infrastructure has been completely rewritten.
4540 The new infrastructure making possible the implementation of key new
4541 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4544 GDB 6.3 will be the last release to include the the registers[]
4545 compatibility module that allowed out-of-date configurations to
4546 continue to work. This change directly impacts the following
4556 powerpc bdm protocol
4558 Unless there is activity to revive these configurations, they will be
4559 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4561 * OBSOLETE configurations and files
4563 Configurations that have been declared obsolete in this release have
4564 been commented out. Unless there is activity to revive these
4565 configurations, the next release of GDB will have their sources
4566 permanently REMOVED.
4575 *** Changes in GDB 6.2.1:
4577 * MIPS `break main; run' gave an heuristic-fence-post warning
4579 When attempting to run even a simple program, a warning about
4580 heuristic-fence-post being hit would be reported. This problem has
4583 * MIPS IRIX 'long double' crashed GDB
4585 When examining a long double variable, GDB would get a segmentation
4586 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4587 IRIX long double values).
4591 A bug in the VAX stack code was causing problems with the "next"
4592 command. This problem has been fixed.
4594 *** Changes in GDB 6.2:
4596 * Fix for ``many threads''
4598 On GNU/Linux systems that use the NPTL threads library, a program
4599 rapidly creating and deleting threads would confuse GDB leading to the
4602 ptrace: No such process.
4603 thread_db_get_info: cannot get thread info: generic error
4605 This problem has been fixed.
4607 * "-async" and "-noasync" options removed.
4609 Support for the broken "-noasync" option has been removed (it caused
4612 * New ``start'' command.
4614 This command runs the program until the begining of the main procedure.
4616 * New BSD Kernel Data Access Library (libkvm) interface
4618 Using ``target kvm'' it is now possible to debug kernel core dumps and
4619 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4620 platforms. Currently supported (native-only) configurations are:
4622 FreeBSD/amd64 x86_64-*-freebsd*
4623 FreeBSD/i386 i?86-*-freebsd*
4624 NetBSD/i386 i?86-*-netbsd*
4625 NetBSD/m68k m68*-*-netbsd*
4626 NetBSD/sparc sparc-*-netbsd*
4627 OpenBSD/amd64 x86_64-*-openbsd*
4628 OpenBSD/i386 i?86-*-openbsd*
4629 OpenBSD/m68k m68*-openbsd*
4630 OpenBSD/sparc sparc-*-openbsd*
4632 * Signal trampoline code overhauled
4634 Many generic problems with GDB's signal handling code have been fixed.
4635 These include: backtraces through non-contiguous stacks; recognition
4636 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4637 call; backtrace through a signal trampoline; step into and out of
4638 signal handlers; and single-stepping in the signal trampoline.
4640 Please note that kernel bugs are a limiting factor here. These
4641 features have been shown to work on an s390 GNU/Linux system that
4642 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4644 * Cygwin support for DWARF 2 added.
4646 * New native configurations
4648 GNU/Linux/hppa hppa*-*-linux*
4649 OpenBSD/hppa hppa*-*-openbsd*
4650 OpenBSD/m68k m68*-*-openbsd*
4651 OpenBSD/m88k m88*-*-openbsd*
4652 OpenBSD/powerpc powerpc-*-openbsd*
4653 NetBSD/vax vax-*-netbsd*
4654 OpenBSD/vax vax-*-openbsd*
4656 * END-OF-LIFE frame compatibility module
4658 GDB's internal frame infrastructure has been completely rewritten.
4659 The new infrastructure making it possible to support key new features
4660 including DWARF 2 Call Frame Information. To aid in the task of
4661 migrating old configurations to this new infrastructure, a
4662 compatibility module, that allowed old configurations to continue to
4663 work, was also included.
4665 GDB 6.2 will be the last release to include this frame compatibility
4666 module. This change directly impacts the following configurations:
4676 Unless there is activity to revive these configurations, they will be
4677 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4679 * REMOVED configurations and files
4681 Sun 3, running SunOS 3 m68*-*-sunos3*
4682 Sun 3, running SunOS 4 m68*-*-sunos4*
4683 Sun 2, running SunOS 3 m68000-*-sunos3*
4684 Sun 2, running SunOS 4 m68000-*-sunos4*
4685 Motorola 680x0 running LynxOS m68*-*-lynxos*
4686 AT&T 3b1/Unix pc m68*-att-*
4687 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4688 decstation mips-dec-* mips-little-*
4689 riscos mips-*-riscos* mips-*-sysv*
4690 sonymips mips-sony-*
4691 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4693 *** Changes in GDB 6.1.1:
4695 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4697 The TUI (Text-mode User Interface) is now built as part of a default
4698 GDB configuration. It is enabled by either selecting the TUI with the
4699 command line option "-i=tui" or by running the separate "gdbtui"
4700 program. For more information on the TUI, see the manual "Debugging
4703 * Pending breakpoint support (also included in GDB 6.1)
4705 Support has been added to allow you to specify breakpoints in shared
4706 libraries that have not yet been loaded. If a breakpoint location
4707 cannot be found, and the "breakpoint pending" option is set to auto,
4708 GDB queries you if you wish to make the breakpoint pending on a future
4709 shared-library load. If and when GDB resolves the breakpoint symbol,
4710 the pending breakpoint is removed as one or more regular breakpoints
4713 Pending breakpoints are very useful for GCJ Java debugging.
4715 * Fixed ISO-C build problems
4717 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4718 non ISO-C code that stopped them being built using a more strict ISO-C
4719 compiler (e.g., IBM's C compiler).
4721 * Fixed build problem on IRIX 5
4723 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4724 wasn't able to compile compile on an IRIX 5 system.
4726 * Added execute permission to gdb/gdbserver/configure
4728 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4729 permission. This bug would cause configure to fail on a number of
4730 systems (Solaris, IRIX). Ref: server/519.
4732 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4734 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4735 has been updated to use constant array sizes.
4737 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4739 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4740 its generated DWARF Call Frame Info. This encoding was causing GDB to
4741 panic, that panic has been fixed. Ref: gdb/1628.
4743 * Fixed a problem when examining parameters in shared library code.
4745 When examining parameters in optimized shared library code generated
4746 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4747 not available''. GDB now correctly displays the variable's value.
4749 *** Changes in GDB 6.1:
4751 * Removed --with-mmalloc
4753 Support for the mmalloc memory manager has been removed, as it
4754 conflicted with the internal gdb byte cache.
4756 * Changes in AMD64 configurations
4758 The AMD64 target now includes the %cs and %ss registers. As a result
4759 the AMD64 remote protocol has changed; this affects the floating-point
4760 and SSE registers. If you rely on those registers for your debugging,
4761 you should upgrade gdbserver on the remote side.
4763 * Revised SPARC target
4765 The SPARC target has been completely revised, incorporating the
4766 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4767 support for LynxOS and SunOS 4 has been dropped. Calling functions
4768 from within GDB on operating systems with a non-executable stack
4769 (Solaris, OpenBSD) now works.
4773 GDB has a new C++ demangler which does a better job on the mangled
4774 names generated by current versions of g++. It also runs faster, so
4775 with this and other changes gdb should now start faster on large C++
4778 * DWARF 2 Location Expressions
4780 GDB support for location expressions has been extended to support function
4781 arguments and frame bases. Older versions of GDB could crash when they
4784 * C++ nested types and namespaces
4786 GDB's support for nested types and namespaces in C++ has been
4787 improved, especially if you use the DWARF 2 debugging format. (This
4788 is the default for recent versions of GCC on most platforms.)
4789 Specifically, if you have a class "Inner" defined within a class or
4790 namespace "Outer", then GDB realizes that the class's name is
4791 "Outer::Inner", not simply "Inner". This should greatly reduce the
4792 frequency of complaints about not finding RTTI symbols. In addition,
4793 if you are stopped at inside of a function defined within a namespace,
4794 GDB modifies its name lookup accordingly.
4796 * New native configurations
4798 NetBSD/amd64 x86_64-*-netbsd*
4799 OpenBSD/amd64 x86_64-*-openbsd*
4800 OpenBSD/alpha alpha*-*-openbsd*
4801 OpenBSD/sparc sparc-*-openbsd*
4802 OpenBSD/sparc64 sparc64-*-openbsd*
4804 * New debugging protocols
4806 M32R with SDI protocol m32r-*-elf*
4808 * "set prompt-escape-char" command deleted.
4810 The command "set prompt-escape-char" has been deleted. This command,
4811 and its very obscure effet on GDB's prompt, was never documented,
4812 tested, nor mentioned in the NEWS file.
4814 * OBSOLETE configurations and files
4816 Configurations that have been declared obsolete in this release have
4817 been commented out. Unless there is activity to revive these
4818 configurations, the next release of GDB will have their sources
4819 permanently REMOVED.
4821 Sun 3, running SunOS 3 m68*-*-sunos3*
4822 Sun 3, running SunOS 4 m68*-*-sunos4*
4823 Sun 2, running SunOS 3 m68000-*-sunos3*
4824 Sun 2, running SunOS 4 m68000-*-sunos4*
4825 Motorola 680x0 running LynxOS m68*-*-lynxos*
4826 AT&T 3b1/Unix pc m68*-att-*
4827 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4828 decstation mips-dec-* mips-little-*
4829 riscos mips-*-riscos* mips-*-sysv*
4830 sonymips mips-sony-*
4831 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4833 * REMOVED configurations and files
4835 SGI Irix-4.x mips-sgi-irix4 or iris4
4836 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4837 Z8000 simulator z8k-zilog-none or z8ksim
4838 Matsushita MN10200 w/simulator mn10200-*-*
4839 H8/500 simulator h8500-hitachi-hms or h8500hms
4840 HP/PA running BSD hppa*-*-bsd*
4841 HP/PA running OSF/1 hppa*-*-osf*
4842 HP/PA Pro target hppa*-*-pro*
4843 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4844 386BSD i[3456]86-*-bsd*
4845 Sequent family i[3456]86-sequent-sysv4*
4846 i[3456]86-sequent-sysv*
4847 i[3456]86-sequent-bsd*
4848 SPARC running LynxOS sparc-*-lynxos*
4849 SPARC running SunOS 4 sparc-*-sunos4*
4850 Tsqware Sparclet sparclet-*-*
4851 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4853 *** Changes in GDB 6.0:
4857 Support for debugging the Objective-C programming language has been
4858 integrated into GDB.
4860 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4862 DWARF 2's Call Frame Information makes available compiler generated
4863 information that more exactly describes the program's run-time stack.
4864 By using this information, GDB is able to provide more robust stack
4867 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4868 have been updated to use a new backtrace mechanism which includes
4869 DWARF 2 CFI support.
4873 GDB's remote protocol has been extended to include support for hosted
4874 file I/O (where the remote target uses GDB's file system). See GDB's
4875 remote protocol documentation for details.
4877 * All targets using the new architecture framework.
4879 All of GDB's targets have been updated to use the new internal
4880 architecture framework. The way is now open for future GDB releases
4881 to include cross-architecture native debugging support (i386 on amd64,
4884 * GNU/Linux's Thread Local Storage (TLS)
4886 GDB now includes support for for the GNU/Linux implementation of
4887 per-thread variables.
4889 * GNU/Linux's Native POSIX Thread Library (NPTL)
4891 GDB's thread code has been updated to work with either the new
4892 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4894 * Separate debug info.
4896 GDB, in conjunction with BINUTILS, now supports a mechanism for
4897 automatically loading debug information from a separate file. Instead
4898 of shipping full debug and non-debug versions of system libraries,
4899 system integrators can now instead ship just the stripped libraries
4900 and optional debug files.
4902 * DWARF 2 Location Expressions
4904 DWARF 2 Location Expressions allow the compiler to more completely
4905 describe the location of variables (even in optimized code) to the
4908 GDB now includes preliminary support for location expressions (support
4909 for DW_OP_piece is still missing).
4913 A number of long standing bugs that caused GDB to die while starting a
4914 Java application have been fixed. GDB's Java support is now
4915 considered "useable".
4917 * GNU/Linux support for fork, vfork, and exec.
4919 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4920 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4923 * GDB supports logging output to a file
4925 There are two new commands, "set logging" and "show logging", which can be
4926 used to capture GDB's output to a file.
4928 * The meaning of "detach" has changed for gdbserver
4930 The "detach" command will now resume the application, as documented. To
4931 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4934 * d10v, m68hc11 `regs' command deprecated
4936 The `info registers' command has been updated so that it displays the
4937 registers using a format identical to the old `regs' command.
4941 A new command, "maint set profile on/off", has been added. This command can
4942 be used to enable or disable profiling while running GDB, to profile a
4943 session or a set of commands. In addition there is a new configure switch,
4944 "--enable-profiling", which will cause GDB to be compiled with profiling
4945 data, for more informative profiling results.
4947 * Default MI syntax changed to "mi2".
4949 The default MI (machine interface) syntax, enabled by the command line
4950 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4951 "mi1", can be enabled by specifying the option "-i=mi1".
4953 Support for the original "mi0" syntax (included in GDB 5.0) has been
4956 Fix for gdb/192: removed extraneous space when displaying frame level.
4957 Fix for gdb/672: update changelist is now output in mi list format.
4958 Fix for gdb/702: a -var-assign that updates the value now shows up
4959 in a subsequent -var-update.
4961 * New native configurations.
4963 FreeBSD/amd64 x86_64-*-freebsd*
4965 * Multi-arched targets.
4967 HP/PA HPUX11 hppa*-*-hpux*
4968 Renesas M32R/D w/simulator m32r-*-elf*
4970 * OBSOLETE configurations and files
4972 Configurations that have been declared obsolete in this release have
4973 been commented out. Unless there is activity to revive these
4974 configurations, the next release of GDB will have their sources
4975 permanently REMOVED.
4977 Z8000 simulator z8k-zilog-none or z8ksim
4978 Matsushita MN10200 w/simulator mn10200-*-*
4979 H8/500 simulator h8500-hitachi-hms or h8500hms
4980 HP/PA running BSD hppa*-*-bsd*
4981 HP/PA running OSF/1 hppa*-*-osf*
4982 HP/PA Pro target hppa*-*-pro*
4983 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4984 Sequent family i[3456]86-sequent-sysv4*
4985 i[3456]86-sequent-sysv*
4986 i[3456]86-sequent-bsd*
4987 Tsqware Sparclet sparclet-*-*
4988 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4990 * REMOVED configurations and files
4993 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4994 IBM AIX PS/2 i[3456]86-*-aix
4995 i386 running Mach 3.0 i[3456]86-*-mach3*
4996 i386 running Mach i[3456]86-*-mach*
4997 i386 running OSF/1 i[3456]86-*osf1mk*
4998 HP/Apollo 68k Family m68*-apollo*-sysv*,
5000 m68*-hp-bsd*, m68*-hp-hpux*
5001 Argonaut Risc Chip (ARC) arc-*-*
5002 Mitsubishi D30V d30v-*-*
5003 Fujitsu FR30 fr30-*-elf*
5004 OS/9000 i[34]86-*-os9k
5005 I960 with MON960 i960-*-coff
5007 * MIPS $fp behavior changed
5009 The convenience variable $fp, for the MIPS, now consistently returns
5010 the address of the current frame's base. Previously, depending on the
5011 context, $fp could refer to either $sp or the current frame's base
5012 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5013 The GNU Source-Level Debugger''.
5015 *** Changes in GDB 5.3:
5017 * GNU/Linux shared library multi-threaded performance improved.
5019 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5020 `/proc', in preference to `ptrace' for memory reads. This may result
5021 in an improvement in the start-up time of multi-threaded, shared
5022 library applications when run under GDB. One GDB user writes: ``loads
5023 shared libs like mad''.
5025 * ``gdbserver'' now supports multi-threaded applications on some targets
5027 Support for debugging multi-threaded applications which use
5028 the GNU/Linux LinuxThreads package has been added for
5029 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5030 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5032 * GDB now supports C/C++ preprocessor macros.
5034 GDB now expands preprocessor macro invocations in C/C++ expressions,
5035 and provides various commands for showing macro definitions and how
5038 The new command `macro expand EXPRESSION' expands any macro
5039 invocations in expression, and shows the result.
5041 The new command `show macro MACRO-NAME' shows the definition of the
5042 macro named MACRO-NAME, and where it was defined.
5044 Most compilers don't include information about macros in the debugging
5045 information by default. In GCC 3.1, for example, you need to compile
5046 your program with the options `-gdwarf-2 -g3'. If the macro
5047 information is present in the executable, GDB will read it.
5049 * Multi-arched targets.
5051 DEC Alpha (partial) alpha*-*-*
5052 DEC VAX (partial) vax-*-*
5054 National Semiconductor NS32000 (partial) ns32k-*-*
5055 Motorola 68000 (partial) m68k-*-*
5056 Motorola MCORE mcore-*-*
5060 Fujitsu FRV architecture added by Red Hat frv*-*-*
5063 * New native configurations
5065 Alpha NetBSD alpha*-*-netbsd*
5066 SH NetBSD sh*-*-netbsdelf*
5067 MIPS NetBSD mips*-*-netbsd*
5068 UltraSPARC NetBSD sparc64-*-netbsd*
5070 * OBSOLETE configurations and files
5072 Configurations that have been declared obsolete in this release have
5073 been commented out. Unless there is activity to revive these
5074 configurations, the next release of GDB will have their sources
5075 permanently REMOVED.
5077 Mitsubishi D30V d30v-*-*
5078 OS/9000 i[34]86-*-os9k
5079 IBM AIX PS/2 i[3456]86-*-aix
5080 Fujitsu FR30 fr30-*-elf*
5081 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5082 Argonaut Risc Chip (ARC) arc-*-*
5083 i386 running Mach 3.0 i[3456]86-*-mach3*
5084 i386 running Mach i[3456]86-*-mach*
5085 i386 running OSF/1 i[3456]86-*osf1mk*
5086 HP/Apollo 68k Family m68*-apollo*-sysv*,
5088 m68*-hp-bsd*, m68*-hp-hpux*
5089 I960 with MON960 i960-*-coff
5091 * OBSOLETE languages
5093 CHILL, a Pascal like language used by telecommunications companies.
5095 * REMOVED configurations and files
5097 AMD 29k family via UDI a29k-amd-udi, udi29k
5098 A29K VxWorks a29k-*-vxworks
5099 AMD 29000 embedded, using EBMON a29k-none-none
5100 AMD 29000 embedded with COFF a29k-none-coff
5101 AMD 29000 embedded with a.out a29k-none-aout
5103 testsuite/gdb.hp/gdb.threads-hp/ directory
5105 * New command "set max-user-call-depth <nnn>"
5107 This command allows the user to limit the call depth of user-defined
5108 commands. The default is 1024.
5110 * Changes in FreeBSD/i386 native debugging.
5112 Support for the "generate-core-file" has been added.
5114 * New commands "dump", "append", and "restore".
5116 These commands allow data to be copied from target memory
5117 to a bfd-format or binary file (dump and append), and back
5118 from a file into memory (restore).
5120 * Improved "next/step" support on multi-processor Alpha Tru64.
5122 The previous single-step mechanism could cause unpredictable problems,
5123 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5124 of a software single-step mechanism prevents this.
5126 *** Changes in GDB 5.2.1:
5134 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5135 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5136 Fix, by Joel Brobecker imported from mainline.
5138 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5139 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5140 Fix, by Fred Fish, imported from mainline.
5142 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5143 Surprisingly enough, it works now.
5144 By Michal Ludvig, imported from mainline.
5146 i386 hardware watchpoint support:
5147 avoid misses on second run for some targets.
5148 By Pierre Muller, imported from mainline.
5150 *** Changes in GDB 5.2:
5152 * New command "set trust-readonly-sections on[off]".
5154 This command is a hint that tells gdb that read-only sections
5155 really are read-only (ie. that their contents will not change).
5156 In this mode, gdb will go to the object file rather than the
5157 target to read memory from read-only sections (such as ".text").
5158 This can be a significant performance improvement on some
5159 (notably embedded) targets.
5161 * New command "generate-core-file" (or "gcore").
5163 This new gdb command allows the user to drop a core file of the child
5164 process state at any time. So far it's been implemented only for
5165 GNU/Linux and Solaris, but should be relatively easily ported to other
5166 hosts. Argument is core file name (defaults to core.<pid>).
5168 * New command line option
5170 GDB now accepts --pid or -p followed by a process id.
5172 * Change in command line behavior -- corefiles vs. process ids.
5174 There is a subtle behavior in the way in which GDB handles
5175 command line arguments. The first non-flag argument is always
5176 a program to debug, but the second non-flag argument may either
5177 be a corefile or a process id. Previously, GDB would attempt to
5178 open the second argument as a corefile, and if that failed, would
5179 issue a superfluous error message and then attempt to attach it as
5180 a process. Now, if the second argument begins with a non-digit,
5181 it will be treated as a corefile. If it begins with a digit,
5182 GDB will attempt to attach it as a process, and if no such process
5183 is found, will then attempt to open it as a corefile.
5185 * Changes in ARM configurations.
5187 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5188 configuration is fully multi-arch.
5190 * New native configurations
5192 ARM NetBSD arm*-*-netbsd*
5193 x86 OpenBSD i[3456]86-*-openbsd*
5194 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5195 Sparc64 running FreeBSD sparc64-*-freebsd*
5199 Sanyo XStormy16 xstormy16-elf
5201 * OBSOLETE configurations and files
5203 Configurations that have been declared obsolete in this release have
5204 been commented out. Unless there is activity to revive these
5205 configurations, the next release of GDB will have their sources
5206 permanently REMOVED.
5208 AMD 29k family via UDI a29k-amd-udi, udi29k
5209 A29K VxWorks a29k-*-vxworks
5210 AMD 29000 embedded, using EBMON a29k-none-none
5211 AMD 29000 embedded with COFF a29k-none-coff
5212 AMD 29000 embedded with a.out a29k-none-aout
5214 testsuite/gdb.hp/gdb.threads-hp/ directory
5216 * REMOVED configurations and files
5218 TI TMS320C80 tic80-*-*
5220 PowerPC Solaris powerpcle-*-solaris*
5221 PowerPC Windows NT powerpcle-*-cygwin32
5222 PowerPC Netware powerpc-*-netware*
5223 Harris/CXUX m88k m88*-harris-cxux*
5224 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5225 ns32k-utek-sysv* ns32k-utek-*
5226 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5227 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5228 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5229 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5230 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5232 * Changes to command line processing
5234 The new `--args' feature can be used to specify command-line arguments
5235 for the inferior from gdb's command line.
5237 * Changes to key bindings
5239 There is a new `operate-and-get-next' function bound to `C-o'.
5241 *** Changes in GDB 5.1.1
5243 Fix compile problem on DJGPP.
5245 Fix a problem with floating-point registers on the i386 being
5248 Fix to stop GDB crashing on .debug_str debug info.
5250 Numerous documentation fixes.
5252 Numerous testsuite fixes.
5254 *** Changes in GDB 5.1:
5256 * New native configurations
5258 Alpha FreeBSD alpha*-*-freebsd*
5259 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5260 MIPS GNU/Linux mips*-*-linux*
5261 MIPS SGI Irix 6.x mips*-sgi-irix6*
5262 ia64 AIX ia64-*-aix*
5263 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5267 Motorola 68HC11 and 68HC12 m68hc11-elf
5269 UltraSparc running GNU/Linux sparc64-*-linux*
5271 * OBSOLETE configurations and files
5273 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5274 Harris/CXUX m88k m88*-harris-cxux*
5275 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5276 ns32k-utek-sysv* ns32k-utek-*
5277 TI TMS320C80 tic80-*-*
5279 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5280 PowerPC Solaris powerpcle-*-solaris*
5281 PowerPC Windows NT powerpcle-*-cygwin32
5282 PowerPC Netware powerpc-*-netware*
5283 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5284 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5285 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5286 Apple Macintosh (MPW) host N/A
5288 stuff.c (Program to stuff files into a specially prepared space in kdb)
5289 kdb-start.c (Main loop for the standalone kernel debugger)
5291 Configurations that have been declared obsolete in this release have
5292 been commented out. Unless there is activity to revive these
5293 configurations, the next release of GDB will have their sources
5294 permanently REMOVED.
5296 * REMOVED configurations and files
5298 Altos 3068 m68*-altos-*
5299 Convex c1-*-*, c2-*-*
5301 ARM RISCix arm-*-* (as host)
5305 * GDB has been converted to ISO C.
5307 GDB's source code has been converted to ISO C. In particular, the
5308 sources are fully protoized, and rely on standard headers being
5313 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5315 * The MI enabled by default.
5317 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5318 revised and enabled by default. Packages which use GDB as a debugging
5319 engine behind a UI or another front end are encouraged to switch to
5320 using the GDB/MI interface, instead of the old annotations interface
5321 which is now deprecated.
5323 * Support for debugging Pascal programs.
5325 GDB now includes support for debugging Pascal programs. The following
5326 main features are supported:
5328 - Pascal-specific data types such as sets;
5330 - automatic recognition of Pascal sources based on file-name
5333 - Pascal-style display of data types, variables, and functions;
5335 - a Pascal expression parser.
5337 However, some important features are not yet supported.
5339 - Pascal string operations are not supported at all;
5341 - there are some problems with boolean types;
5343 - Pascal type hexadecimal constants are not supported
5344 because they conflict with the internal variables format;
5346 - support for Pascal objects and classes is not full yet;
5348 - unlike Pascal, GDB is case-sensitive for symbol names.
5350 * Changes in completion.
5352 Commands such as `shell', `run' and `set args', which pass arguments
5353 to inferior programs, now complete on file names, similar to what
5354 users expect at the shell prompt.
5356 Commands which accept locations, such as `disassemble', `print',
5357 `breakpoint', `until', etc. now complete on filenames as well as
5358 program symbols. Thus, if you type "break foob TAB", and the source
5359 files linked into the programs include `foobar.c', that file name will
5360 be one of the candidates for completion. However, file names are not
5361 considered for completion after you typed a colon that delimits a file
5362 name from a name of a function in that file, as in "break foo.c:bar".
5364 `set demangle-style' completes on available demangling styles.
5366 * New platform-independent commands:
5368 It is now possible to define a post-hook for a command as well as a
5369 hook that runs before the command. For more details, see the
5370 documentation of `hookpost' in the GDB manual.
5372 * Changes in GNU/Linux native debugging.
5374 Support for debugging multi-threaded programs has been completely
5375 revised for all platforms except m68k and sparc. You can now debug as
5376 many threads as your system allows you to have.
5378 Attach/detach is supported for multi-threaded programs.
5380 Support for SSE registers was added for x86. This doesn't work for
5381 multi-threaded programs though.
5383 * Changes in MIPS configurations.
5385 Multi-arch support is enabled for all MIPS configurations.
5387 GDB can now be built as native debugger on SGI Irix 6.x systems for
5388 debugging n32 executables. (Debugging 64-bit executables is not yet
5391 * Unified support for hardware watchpoints in all x86 configurations.
5393 Most (if not all) native x86 configurations support hardware-assisted
5394 breakpoints and watchpoints in a unified manner. This support
5395 implements debug register sharing between watchpoints, which allows to
5396 put a virtually infinite number of watchpoints on the same address,
5397 and also supports watching regions up to 16 bytes with several debug
5400 The new maintenance command `maintenance show-debug-regs' toggles
5401 debugging print-outs in functions that insert, remove, and test
5402 watchpoints and hardware breakpoints.
5404 * Changes in the DJGPP native configuration.
5406 New command ``info dos sysinfo'' displays assorted information about
5407 the CPU, OS, memory, and DPMI server.
5409 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5410 display information about segment descriptors stored in GDT, LDT, and
5413 New commands ``info dos pde'' and ``info dos pte'' display entries
5414 from Page Directory and Page Tables (for now works with CWSDPMI only).
5415 New command ``info dos address-pte'' displays the Page Table entry for
5416 a given linear address.
5418 GDB can now pass command lines longer than 126 characters to the
5419 program being debugged (requires an update to the libdbg.a library
5420 which is part of the DJGPP development kit).
5422 DWARF2 debug info is now supported.
5424 It is now possible to `step' and `next' through calls to `longjmp'.
5426 * Changes in documentation.
5428 All GDB documentation was converted to GFDL, the GNU Free
5429 Documentation License.
5431 Tracepoints-related commands are now fully documented in the GDB
5434 TUI, the Text-mode User Interface, is now documented in the manual.
5436 Tracepoints-related commands are now fully documented in the GDB
5439 The "GDB Internals" manual now has an index. It also includes
5440 documentation of `ui_out' functions, GDB coding standards, x86
5441 hardware watchpoints, and memory region attributes.
5443 * GDB's version number moved to ``version.in''
5445 The Makefile variable VERSION has been replaced by the file
5446 ``version.in''. People creating GDB distributions should update the
5447 contents of this file.
5451 GUD support is now a standard part of the EMACS distribution.
5453 *** Changes in GDB 5.0:
5455 * Improved support for debugging FP programs on x86 targets
5457 Unified and much-improved support for debugging floating-point
5458 programs on all x86 targets. In particular, ``info float'' now
5459 displays the FP registers in the same format on all x86 targets, with
5460 greater level of detail.
5462 * Improvements and bugfixes in hardware-assisted watchpoints
5464 It is now possible to watch array elements, struct members, and
5465 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5466 on x86 targets no longer erroneously trigger when the address is
5469 * Improvements in the native DJGPP version of GDB
5471 The distribution now includes all the scripts and auxiliary files
5472 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5473 machines ``out of the box''.
5475 The DJGPP version can now debug programs that use signals. It is
5476 possible to catch signals that happened in the debuggee, deliver
5477 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5478 would kill the program being debugged.) Programs that hook hardware
5479 interrupts (keyboard, timer, etc.) can also be debugged.
5481 It is now possible to debug DJGPP programs that redirect their
5482 standard handles or switch them to raw (as opposed to cooked) mode, or
5483 even close them. The command ``run < foo > bar'' works as expected,
5484 and ``info terminal'' reports useful information about the debuggee's
5485 terminal, including raw/cooked mode, redirection, etc.
5487 The DJGPP version now uses termios functions for console I/O, which
5488 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5491 DOS-style file names with drive letters are now fully supported by
5494 It is now possible to debug DJGPP programs that switch their working
5495 directory. It is also possible to rerun the debuggee any number of
5496 times without restarting GDB; thus, you can use the same setup,
5497 breakpoints, etc. for many debugging sessions.
5499 * New native configurations
5501 ARM GNU/Linux arm*-*-linux*
5502 PowerPC GNU/Linux powerpc-*-linux*
5506 Motorola MCore mcore-*-*
5507 x86 VxWorks i[3456]86-*-vxworks*
5508 PowerPC VxWorks powerpc-*-vxworks*
5509 TI TMS320C80 tic80-*-*
5511 * OBSOLETE configurations
5513 Altos 3068 m68*-altos-*
5514 Convex c1-*-*, c2-*-*
5516 ARM RISCix arm-*-* (as host)
5519 Configurations that have been declared obsolete will be commented out,
5520 but the code will be left in place. If there is no activity to revive
5521 these configurations before the next release of GDB, the sources will
5522 be permanently REMOVED.
5524 * Gould support removed
5526 Support for the Gould PowerNode and NP1 has been removed.
5528 * New features for SVR4
5530 On SVR4 native platforms (such as Solaris), if you attach to a process
5531 without first loading a symbol file, GDB will now attempt to locate and
5532 load symbols from the running process's executable file.
5534 * Many C++ enhancements
5536 C++ support has been greatly improved. Overload resolution now works properly
5537 in almost all cases. RTTI support is on the way.
5539 * Remote targets can connect to a sub-program
5541 A popen(3) style serial-device has been added. This device starts a
5542 sub-process (such as a stand-alone simulator) and then communicates
5543 with that. The sub-program to run is specified using the syntax
5544 ``|<program> <args>'' vis:
5546 (gdb) set remotedebug 1
5547 (gdb) target extended-remote |mn10300-elf-sim program-args
5549 * MIPS 64 remote protocol
5551 A long standing bug in the mips64 remote protocol where by GDB
5552 expected certain 32 bit registers (ex SR) to be transfered as 32
5553 instead of 64 bits has been fixed.
5555 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5556 added to provide backward compatibility with older versions of GDB.
5558 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5560 The command ``set remotebinarydownload'' command has been replaced by
5561 ``set remote X-packet''. Other commands in ``set remote'' family
5562 include ``set remote P-packet''.
5564 * Breakpoint commands accept ranges.
5566 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5567 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5568 ``tracepoint passcount'' also accepts a range of tracepoints.
5570 * ``apropos'' command added.
5572 The ``apropos'' command searches through command names and
5573 documentation strings, printing out matches, making it much easier to
5574 try to find a command that does what you are looking for.
5578 A new machine oriented interface (MI) has been added to GDB. This
5579 interface is designed for debug environments running GDB as a separate
5580 process. This is part of the long term libGDB project. See the
5581 "GDB/MI" chapter of the GDB manual for further information. It can be
5582 enabled by configuring with:
5584 .../configure --enable-gdbmi
5586 *** Changes in GDB-4.18:
5588 * New native configurations
5590 HP-UX 10.20 hppa*-*-hpux10.20
5591 HP-UX 11.x hppa*-*-hpux11.0*
5592 M68K GNU/Linux m68*-*-linux*
5596 Fujitsu FR30 fr30-*-elf*
5597 Intel StrongARM strongarm-*-*
5598 Mitsubishi D30V d30v-*-*
5600 * OBSOLETE configurations
5602 Gould PowerNode, NP1 np1-*-*, pn-*-*
5604 Configurations that have been declared obsolete will be commented out,
5605 but the code will be left in place. If there is no activity to revive
5606 these configurations before the next release of GDB, the sources will
5607 be permanently REMOVED.
5611 As a compatibility experiment, GDB's source files buildsym.h and
5612 buildsym.c have been converted to pure standard C, no longer
5613 containing any K&R compatibility code. We believe that all systems in
5614 use today either come with a standard C compiler, or have a GCC port
5615 available. If this is not true, please report the affected
5616 configuration to bug-gdb@gnu.org immediately. See the README file for
5617 information about getting a standard C compiler if you don't have one
5622 GDB now uses readline 2.2.
5624 * set extension-language
5626 You can now control the mapping between filename extensions and source
5627 languages by using the `set extension-language' command. For instance,
5628 you can ask GDB to treat .c files as C++ by saying
5629 set extension-language .c c++
5630 The command `info extensions' lists all of the recognized extensions
5631 and their associated languages.
5633 * Setting processor type for PowerPC and RS/6000
5635 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5636 you can use the `set processor' command to specify what variant of the
5637 PowerPC family you are debugging. The command
5641 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5642 following PowerPC and RS6000 variants:
5644 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5645 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5647 403GC IBM PowerPC 403GC
5648 505 Motorola PowerPC 505
5649 860 Motorola PowerPC 860 or 850
5650 601 Motorola PowerPC 601
5651 602 Motorola PowerPC 602
5652 603 Motorola/IBM PowerPC 603 or 603e
5653 604 Motorola PowerPC 604 or 604e
5654 750 Motorola/IBM PowerPC 750 or 750
5656 At the moment, this command just tells GDB what to name the
5657 special-purpose processor registers. Since almost all the affected
5658 registers are inaccessible to user-level programs, this command is
5659 only useful for remote debugging in its present form.
5663 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5664 more extensive support for HP-UX. Added features include shared
5665 library support, kernel threads and hardware watchpoints for 11.00,
5666 support for HP's ANSI C and C++ compilers, and a compatibility mode
5667 for xdb and dbx commands.
5671 HP's donation includes the new concept of catchpoints, which is a
5672 generalization of the old catch command. On HP-UX, it is now possible
5673 to catch exec, fork, and vfork, as well as library loading.
5675 This means that the existing catch command has changed; its first
5676 argument now specifies the type of catch to be set up. See the
5677 output of "help catch" for a list of catchpoint types.
5679 * Debugging across forks
5681 On HP-UX, you can choose which process to debug when a fork() happens
5686 HP has donated a curses-based terminal user interface (TUI). To get
5687 it, build with --enable-tui. Although this can be enabled for any
5688 configuration, at present it only works for native HP debugging.
5690 * GDB remote protocol additions
5692 A new protocol packet 'X' that writes binary data is now available.
5693 Default behavior is to try 'X', then drop back to 'M' if the stub
5694 fails to respond. The settable variable `remotebinarydownload'
5695 allows explicit control over the use of 'X'.
5697 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5698 full 64-bit address. The command
5700 set remoteaddresssize 32
5702 can be used to revert to the old behaviour. For existing remote stubs
5703 the change should not be noticed, as the additional address information
5706 In order to assist in debugging stubs, you may use the maintenance
5707 command `packet' to send any text string to the stub. For instance,
5709 maint packet heythere
5711 sends the packet "$heythere#<checksum>". Note that it is very easy to
5712 disrupt a debugging session by sending the wrong packet at the wrong
5715 The compare-sections command allows you to compare section data on the
5716 target to what is in the executable file without uploading or
5717 downloading, by comparing CRC checksums.
5719 * Tracing can collect general expressions
5721 You may now collect general expressions at tracepoints. This requires
5722 further additions to the target-side stub; see tracepoint.c and
5723 doc/agentexpr.texi for further details.
5725 * mask-address variable for Mips
5727 For Mips targets, you may control the zeroing of the upper 32 bits of
5728 a 64-bit address by entering `set mask-address on'. This is mainly
5729 of interest to users of embedded R4xxx and R5xxx processors.
5731 * Higher serial baud rates
5733 GDB's serial code now allows you to specify baud rates 57600, 115200,
5734 230400, and 460800 baud. (Note that your host system may not be able
5735 to achieve all of these rates.)
5739 The i960 configuration now includes an initial implementation of a
5740 builtin simulator, contributed by Jim Wilson.
5743 *** Changes in GDB-4.17:
5745 * New native configurations
5747 Alpha GNU/Linux alpha*-*-linux*
5748 Unixware 2.x i[3456]86-unixware2*
5749 Irix 6.x mips*-sgi-irix6*
5750 PowerPC GNU/Linux powerpc-*-linux*
5751 PowerPC Solaris powerpcle-*-solaris*
5752 Sparc GNU/Linux sparc-*-linux*
5753 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5757 Argonaut Risc Chip (ARC) arc-*-*
5758 Hitachi H8/300S h8300*-*-*
5759 Matsushita MN10200 w/simulator mn10200-*-*
5760 Matsushita MN10300 w/simulator mn10300-*-*
5761 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5762 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5763 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5764 Mitsubishi D10V w/simulator d10v-*-*
5765 Mitsubishi M32R/D w/simulator m32r-*-elf*
5766 Tsqware Sparclet sparclet-*-*
5767 NEC V850 w/simulator v850-*-*
5769 * New debugging protocols
5771 ARM with RDI protocol arm*-*-*
5772 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5773 DDB and LSI variants of PMON protocol mips*-*-*
5774 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5775 PowerPC with SDS protocol powerpc{,le}-*-eabi
5776 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5780 All configurations can now understand and use the DWARF 2 debugging
5781 format. The choice is automatic, if the symbol file contains DWARF 2
5786 GDB now includes basic Java language support. This support is
5787 only useful with Java compilers that produce native machine code.
5789 * solib-absolute-prefix and solib-search-path
5791 For SunOS and SVR4 shared libraries, you may now set the prefix for
5792 loading absolute shared library symbol files, and the search path for
5793 locating non-absolute shared library symbol files.
5795 * Live range splitting
5797 GDB can now effectively debug code for which GCC has performed live
5798 range splitting as part of its optimization. See gdb/doc/LRS for
5799 more details on the expected format of the stabs information.
5803 GDB's support for the GNU Hurd, including thread debugging, has been
5804 updated to work with current versions of the Hurd.
5808 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5809 instruction set. ARM GDB automatically detects when Thumb
5810 instructions are in use, and adjusts disassembly and backtracing
5815 GDB's MIPS target configurations now handle the MIP16 16-bit
5820 GDB now includes support for overlays; if an executable has been
5821 linked such that multiple sections are based at the same address, GDB
5822 will decide which section to use for symbolic info. You can choose to
5823 control the decision manually, using overlay commands, or implement
5824 additional target-side support and use "overlay load-target" to bring
5825 in the overlay mapping. Do "help overlay" for more detail.
5829 The command "info symbol <address>" displays information about
5830 the symbol at the specified address.
5834 The standard remote protocol now includes an extension that allows
5835 asynchronous collection and display of trace data. This requires
5836 extensive support in the target-side debugging stub. Tracing mode
5837 includes a new interaction mode in GDB and new commands: see the
5838 file tracepoint.c for more details.
5842 Configurations for embedded MIPS now include a simulator contributed
5843 by Cygnus Solutions. The simulator supports the instruction sets
5844 of most MIPS variants.
5848 Sparc configurations may now include the ERC32 simulator contributed
5849 by the European Space Agency. The simulator is not built into
5850 Sparc targets by default; configure with --enable-sim to include it.
5854 For target configurations that may include multiple variants of a
5855 basic architecture (such as MIPS and SH), you may now set the
5856 architecture explicitly. "set arch" sets, "info arch" lists
5857 the possible architectures.
5859 *** Changes in GDB-4.16:
5861 * New native configurations
5863 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5864 M68K NetBSD m68k-*-netbsd*
5865 PowerPC AIX 4.x powerpc-*-aix*
5866 PowerPC MacOS powerpc-*-macos*
5867 PowerPC Windows NT powerpcle-*-cygwin32
5868 RS/6000 AIX 4.x rs6000-*-aix4*
5872 ARM with RDP protocol arm-*-*
5873 I960 with MON960 i960-*-coff
5874 MIPS VxWorks mips*-*-vxworks*
5875 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5876 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5878 Matra Sparclet sparclet-*-*
5882 The powerpc-eabi configuration now includes the PSIM simulator,
5883 contributed by Andrew Cagney, with assistance from Mike Meissner.
5884 PSIM is a very elaborate model of the PowerPC, including not only
5885 basic instruction set execution, but also details of execution unit
5886 performance and I/O hardware. See sim/ppc/README for more details.
5890 GDB now works with Solaris 2.5.
5892 * Windows 95/NT native
5894 GDB will now work as a native debugger on Windows 95 and Windows NT.
5895 To build it from source, you must use the "gnu-win32" environment,
5896 which uses a DLL to emulate enough of Unix to run the GNU tools.
5897 Further information, binaries, and sources are available at
5898 ftp.cygnus.com, under pub/gnu-win32.
5900 * dont-repeat command
5902 If a user-defined command includes the command `dont-repeat', then the
5903 command will not be repeated if the user just types return. This is
5904 useful if the command is time-consuming to run, so that accidental
5905 extra keystrokes don't run the same command many times.
5907 * Send break instead of ^C
5909 The standard remote protocol now includes an option to send a break
5910 rather than a ^C to the target in order to interrupt it. By default,
5911 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5913 * Remote protocol timeout
5915 The standard remote protocol includes a new variable `remotetimeout'
5916 that allows you to set the number of seconds before GDB gives up trying
5917 to read from the target. The default value is 2.
5919 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5921 By default GDB will automatically keep track of objects as they are
5922 loaded and unloaded by the dynamic linker. By using the command `set
5923 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5924 when shared library events occur, thus allowing you to set breakpoints
5925 in shared libraries which are explicitly loaded by the inferior.
5927 Note this feature does not work on hpux8. On hpux9 you must link
5928 /usr/lib/end.o into your program. This feature should work
5929 automatically on hpux10.
5931 * Irix 5.x hardware watchpoint support
5933 Irix 5 configurations now support the use of hardware watchpoints.
5935 * Mips protocol "SYN garbage limit"
5937 When debugging a Mips target using the `target mips' protocol, you
5938 may set the number of characters that GDB will ignore by setting
5939 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5940 every character. The default value is 1050.
5942 * Recording and replaying remote debug sessions
5944 If you set `remotelogfile' to the name of a file, gdb will write to it
5945 a recording of a remote debug session. This recording may then be
5946 replayed back to gdb using "gdbreplay". See gdbserver/README for
5947 details. This is useful when you have a problem with GDB while doing
5948 remote debugging; you can make a recording of the session and send it
5949 to someone else, who can then recreate the problem.
5951 * Speedups for remote debugging
5953 GDB includes speedups for downloading and stepping MIPS systems using
5954 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5955 and more efficient S-record downloading.
5957 * Memory use reductions and statistics collection
5959 GDB now uses less memory and reports statistics about memory usage.
5960 Try the `maint print statistics' command, for example.
5962 *** Changes in GDB-4.15:
5964 * Psymtabs for XCOFF
5966 The symbol reader for AIX GDB now uses partial symbol tables. This
5967 can greatly improve startup time, especially for large executables.
5969 * Remote targets use caching
5971 Remote targets now use a data cache to speed up communication with the
5972 remote side. The data cache could lead to incorrect results because
5973 it doesn't know about volatile variables, thus making it impossible to
5974 debug targets which use memory mapped I/O devices. `set remotecache
5975 off' turns the the data cache off.
5977 * Remote targets may have threads
5979 The standard remote protocol now includes support for multiple threads
5980 in the target system, using new protocol commands 'H' and 'T'. See
5981 gdb/remote.c for details.
5985 If GDB is configured with `--enable-netrom', then it will include
5986 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5987 acts as though it is a bank of ROM on the target board, but you can
5988 write into it over the network. GDB's support consists only of
5989 support for fast loading into the emulated ROM; to debug, you must use
5990 another protocol, such as standard remote protocol. The usual
5991 sequence is something like
5993 target nrom <netrom-hostname>
5995 target remote <netrom-hostname>:1235
5999 GDB now includes support for the Apple Macintosh, as a host only. It
6000 may be run as either an MPW tool or as a standalone application, and
6001 it can debug through the serial port. All the usual GDB commands are
6002 available, but to the target command, you must supply "serial" as the
6003 device type instead of "/dev/ttyXX". See mpw-README in the main
6004 directory for more information on how to build. The MPW configuration
6005 scripts */mpw-config.in support only a few targets, and only the
6006 mips-idt-ecoff target has been tested.
6010 GDB configuration now uses autoconf. This is not user-visible,
6011 but does simplify configuration and building.
6015 GDB now supports hpux10.
6017 *** Changes in GDB-4.14:
6019 * New native configurations
6021 x86 FreeBSD i[345]86-*-freebsd
6022 x86 NetBSD i[345]86-*-netbsd
6023 NS32k NetBSD ns32k-*-netbsd
6024 Sparc NetBSD sparc-*-netbsd
6028 A29K VxWorks a29k-*-vxworks
6029 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6030 CPU32 EST-300 emulator m68*-*-est*
6031 PowerPC ELF powerpc-*-elf
6034 * Alpha OSF/1 support for procfs
6036 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6037 possible to attach to running processes. As the mounting of the /proc
6038 filesystem is optional on the Alpha, GDB automatically determines
6039 the availability of /proc during startup. This can lead to problems
6040 if /proc is unmounted after GDB has been started.
6042 * Arguments to user-defined commands
6044 User commands may accept up to 10 arguments separated by whitespace.
6045 Arguments are accessed within the user command via $arg0..$arg9. A
6048 print $arg0 + $arg1 + $arg2
6050 To execute the command use:
6053 Defines the command "adder" which prints the sum of its three arguments.
6054 Note the arguments are text substitutions, so they may reference variables,
6055 use complex expressions, or even perform inferior function calls.
6057 * New `if' and `while' commands
6059 This makes it possible to write more sophisticated user-defined
6060 commands. Both commands take a single argument, which is the
6061 expression to evaluate, and must be followed by the commands to
6062 execute, one per line, if the expression is nonzero, the list being
6063 terminated by the word `end'. The `if' command list may include an
6064 `else' word, which causes the following commands to be executed only
6065 if the expression is zero.
6067 * Fortran source language mode
6069 GDB now includes partial support for Fortran 77. It will recognize
6070 Fortran programs and can evaluate a subset of Fortran expressions, but
6071 variables and functions may not be handled correctly. GDB will work
6072 with G77, but does not yet know much about symbols emitted by other
6075 * Better HPUX support
6077 Most debugging facilities now work on dynamic executables for HPPAs
6078 running hpux9 or later. You can attach to running dynamically linked
6079 processes, but by default the dynamic libraries will be read-only, so
6080 for instance you won't be able to put breakpoints in them. To change
6081 that behavior do the following before running the program:
6087 This will cause the libraries to be mapped private and read-write.
6088 To revert to the normal behavior, do this:
6094 You cannot set breakpoints or examine data in the library until after
6095 the library is loaded if the function/data symbols do not have
6098 GDB can now also read debug symbols produced by the HP C compiler on
6099 HPPAs (sorry, no C++, Fortran or 68k support).
6101 * Target byte order now dynamically selectable
6103 You can choose which byte order to use with a target system, via the
6104 commands "set endian big" and "set endian little", and you can see the
6105 current setting by using "show endian". You can also give the command
6106 "set endian auto", in which case GDB will use the byte order
6107 associated with the executable. Currently, only embedded MIPS
6108 configurations support dynamic selection of target byte order.
6110 * New DOS host serial code
6112 This version uses DPMI interrupts to handle buffered I/O, so you
6113 no longer need to run asynctsr when debugging boards connected to
6116 *** Changes in GDB-4.13:
6118 * New "complete" command
6120 This lists all the possible completions for the rest of the line, if it
6121 were to be given as a command itself. This is intended for use by emacs.
6123 * Trailing space optional in prompt
6125 "set prompt" no longer adds a space for you after the prompt you set. This
6126 allows you to set a prompt which ends in a space or one that does not.
6128 * Breakpoint hit counts
6130 "info break" now displays a count of the number of times the breakpoint
6131 has been hit. This is especially useful in conjunction with "ignore"; you
6132 can ignore a large number of breakpoint hits, look at the breakpoint info
6133 to see how many times the breakpoint was hit, then run again, ignoring one
6134 less than that number, and this will get you quickly to the last hit of
6137 * Ability to stop printing at NULL character
6139 "set print null-stop" will cause GDB to stop printing the characters of
6140 an array when the first NULL is encountered. This is useful when large
6141 arrays actually contain only short strings.
6143 * Shared library breakpoints
6145 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6146 breakpoints in shared libraries before the executable is run.
6148 * Hardware watchpoints
6150 There is a new hardware breakpoint for the watch command for sparclite
6151 targets. See gdb/sparclite/hw_breakpoint.note.
6153 Hardware watchpoints are also now supported under GNU/Linux.
6157 Annotations have been added. These are for use with graphical interfaces,
6158 and are still experimental. Currently only gdba.el uses these.
6160 * Improved Irix 5 support
6162 GDB now works properly with Irix 5.2.
6164 * Improved HPPA support
6166 GDB now works properly with the latest GCC and GAS.
6168 * New native configurations
6170 Sequent PTX4 i[34]86-sequent-ptx4
6171 HPPA running OSF/1 hppa*-*-osf*
6172 Atari TT running SVR4 m68*-*-sysv4*
6173 RS/6000 LynxOS rs6000-*-lynxos*
6177 OS/9000 i[34]86-*-os9k
6178 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6181 * Hitachi SH7000 and E7000-PC ICE support
6183 There is now support for communicating with the Hitachi E7000-PC ICE.
6184 This is available automatically when GDB is configured for the SH.
6188 As usual, a variety of small fixes and improvements, both generic
6189 and configuration-specific. See the ChangeLog for more detail.
6191 *** Changes in GDB-4.12:
6193 * Irix 5 is now supported
6197 GDB-4.12 on the HPPA has a number of changes which make it unable
6198 to debug the output from the currently released versions of GCC and
6199 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6200 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6201 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6204 *** Changes in GDB-4.11:
6206 * User visible changes:
6210 The "set remotedebug" option is now consistent between the mips remote
6211 target, remote targets using the gdb-specific protocol, UDI (AMD's
6212 debug protocol for the 29k) and the 88k bug monitor. It is now an
6213 integer specifying a debug level (normally 0 or 1, but 2 means more
6214 debugging info for the mips target).
6216 * DEC Alpha native support
6218 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6219 debug info, but GDB works fairly well with the DEC compiler and should
6220 work with a future GCC release. See the README file for a few
6221 Alpha-specific notes.
6223 * Preliminary thread implementation
6225 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6227 * LynxOS native and target support for 386
6229 This release has been hosted on LynxOS 2.2, and also can be configured
6230 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6233 * Improvements in C++ mangling/demangling.
6235 This release has much better g++ debugging, specifically in name
6236 mangling/demangling, virtual function calls, print virtual table,
6237 call methods, ...etc.
6239 *** Changes in GDB-4.10:
6241 * User visible changes:
6243 Remote debugging using the GDB-specific (`target remote') protocol now
6244 supports the `load' command. This is only useful if you have some
6245 other way of getting the stub to the target system, and you can put it
6246 somewhere in memory where it won't get clobbered by the download.
6248 Filename completion now works.
6250 When run under emacs mode, the "info line" command now causes the
6251 arrow to point to the line specified. Also, "info line" prints
6252 addresses in symbolic form (as well as hex).
6254 All vxworks based targets now support a user settable option, called
6255 vxworks-timeout. This option represents the number of seconds gdb
6256 should wait for responses to rpc's. You might want to use this if
6257 your vxworks target is, perhaps, a slow software simulator or happens
6258 to be on the far side of a thin network line.
6262 This release contains support for using a DEC alpha as a GDB host for
6263 cross debugging. Native alpha debugging is not supported yet.
6266 *** Changes in GDB-4.9:
6270 This is the first GDB release which is accompanied by a matching testsuite.
6271 The testsuite requires installation of dejagnu, which should be available
6272 via ftp from most sites that carry GNU software.
6276 'Cfront' style demangling has had its name changed to 'ARM' style, to
6277 emphasize that it was written from the specifications in the C++ Annotated
6278 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6279 disclaimers, it still generated too much confusion with users attempting to
6280 use gdb with AT&T cfront.
6284 GDB now uses a standard remote interface to a simulator library.
6285 So far, the library contains simulators for the Zilog Z8001/2, the
6286 Hitachi H8/300, H8/500 and Super-H.
6288 * New targets supported
6290 H8/300 simulator h8300-hitachi-hms or h8300hms
6291 H8/500 simulator h8500-hitachi-hms or h8500hms
6292 SH simulator sh-hitachi-hms or sh
6293 Z8000 simulator z8k-zilog-none or z8ksim
6294 IDT MIPS board over serial line mips-idt-ecoff
6296 Cross-debugging to GO32 targets is supported. It requires a custom
6297 version of the i386-stub.c module which is integrated with the
6298 GO32 memory extender.
6300 * New remote protocols
6302 MIPS remote debugging protocol.
6304 * New source languages supported
6306 This version includes preliminary support for Chill, a Pascal like language
6307 used by telecommunications companies. Chill support is also being integrated
6308 into the GNU compiler, but we don't know when it will be publically available.
6311 *** Changes in GDB-4.8:
6313 * HP Precision Architecture supported
6315 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6316 version of this support was available as a set of patches from the
6317 University of Utah. GDB does not support debugging of programs
6318 compiled with the HP compiler, because HP will not document their file
6319 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6320 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6322 Many problems in the preliminary version have been fixed.
6324 * Faster and better demangling
6326 We have improved template demangling and fixed numerous bugs in the GNU style
6327 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6328 character types (wchar_t) are now supported. Demangling of each symbol is now
6329 only done once, and is cached when the symbol table for a file is read in.
6330 This results in a small increase in memory usage for C programs, a moderate
6331 increase in memory usage for C++ programs, and a fantastic speedup in
6334 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6335 from the specifications in the Annotated Reference Manual, which AT&T's
6336 compiler does not actually implement.
6338 * G++ multiple inheritance compiler problem
6340 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6341 inheritance lattices was reworked to properly discover ambiguities. We
6342 recently found an example which causes this new algorithm to fail in a
6343 very subtle way, producing bad debug information for those classes.
6344 The file 'gcc.patch' (in this directory) can be applied to gcc to
6345 circumvent the problem. A future GCC release will contain a complete
6348 The previous G++ debug info problem (mentioned below for the gdb-4.7
6349 release) is fixed in gcc version 2.3.2.
6351 * Improved configure script
6353 The `configure' script will now attempt to guess your system type if
6354 you don't supply a host system type. The old scheme of supplying a
6355 host system triplet is preferable over using this. All the magic is
6356 done in the new `config.guess' script. Examine it for details.
6358 We have also brought our configure script much more in line with the FSF's
6359 version. It now supports the --with-xxx options. In particular,
6360 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6361 The resulting GDB will not be able to read arbitrary object file formats --
6362 only the format ``expected'' to be used on the configured target system.
6363 We hope to make this the default in a future release.
6365 * Documentation improvements
6367 There's new internal documentation on how to modify GDB, and how to
6368 produce clean changes to the code. We implore people to read it
6369 before submitting changes.
6371 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6372 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6373 `info' files are also provided. To build `info' files from scratch,
6374 you will need the latest `makeinfo' release, which will be available in
6375 a future texinfo-X.Y release.
6377 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6378 We're not sure exactly which versions have this problem, but it has
6379 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6380 or better. If that isn't possible, there is a patch in
6381 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6382 around this problem.
6386 GDB now supports array constants that can be used in expressions typed in by
6387 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6388 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6391 The new directory `gdb/sparclite' contains a program that demonstrates
6392 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6394 * New native hosts supported
6396 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6397 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6399 * New targets supported
6401 AMD 29k family via UDI a29k-amd-udi or udi29k
6403 * New file formats supported
6405 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6406 HPUX core files, and SCO 3.2v2 core files.
6410 Attaching to processes now works again; thanks for the many bug reports.
6412 We have also stomped on a bunch of core dumps caused by
6413 printf_filtered("%s") problems.
6415 We eliminated a copyright problem on the rpc and ptrace header files
6416 for VxWorks, which was discovered at the last minute during the 4.7
6417 release. You should now be able to build a VxWorks GDB.
6419 You can now interrupt gdb while an attached process is running. This
6420 will cause the attached process to stop, and give control back to GDB.
6422 We fixed problems caused by using too many file descriptors
6423 for reading symbols from object files and libraries. This was
6424 especially a problem for programs that used many (~100) shared
6427 The `step' command now only enters a subroutine if there is line number
6428 information for the subroutine. Otherwise it acts like the `next'
6429 command. Previously, `step' would enter subroutines if there was
6430 any debugging information about the routine. This avoids problems
6431 when using `cc -g1' on MIPS machines.
6433 * Internal improvements
6435 GDB's internal interfaces have been improved to make it easier to support
6436 debugging of multiple languages in the future.
6438 GDB now uses a common structure for symbol information internally.
6439 Minimal symbols (derived from linkage symbols in object files), partial
6440 symbols (from a quick scan of debug information), and full symbols
6441 contain a common subset of information, making it easier to write
6442 shared code that handles any of them.
6444 * New command line options
6446 We now accept --silent as an alias for --quiet.
6450 The memory-mapped-malloc library is now licensed under the GNU Library
6451 General Public License.
6453 *** Changes in GDB-4.7:
6455 * Host/native/target split
6457 GDB has had some major internal surgery to untangle the support for
6458 hosts and remote targets. Now, when you configure GDB for a remote
6459 target, it will no longer load in all of the support for debugging
6460 local programs on the host. When fully completed and tested, this will
6461 ensure that arbitrary host/target combinations are possible.
6463 The primary conceptual shift is to separate the non-portable code in
6464 GDB into three categories. Host specific code is required any time GDB
6465 is compiled on that host, regardless of the target. Target specific
6466 code relates to the peculiarities of the target, but can be compiled on
6467 any host. Native specific code is everything else: it can only be
6468 built when the host and target are the same system. Child process
6469 handling and core file support are two common `native' examples.
6471 GDB's use of /proc for controlling Unix child processes is now cleaner.
6472 It has been split out into a single module under the `target_ops' vector,
6473 plus two native-dependent functions for each system that uses /proc.
6475 * New hosts supported
6477 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6478 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6479 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6481 * New targets supported
6483 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6484 68030 and CPU32 m68030-*-*, m68332-*-*
6486 * New native hosts supported
6488 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6489 (386bsd is not well tested yet)
6490 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6492 * New file formats supported
6494 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6495 supports reading of `a.out.adobe' object files, which are an a.out
6496 format extended with minimal information about multiple sections.
6500 `show copying' is the same as the old `info copying'.
6501 `show warranty' is the same as `info warrantee'.
6502 These were renamed for consistency. The old commands continue to work.
6504 `info handle' is a new alias for `info signals'.
6506 You can now define pre-command hooks, which attach arbitrary command
6507 scripts to any command. The commands in the hook will be executed
6508 prior to the user's command. You can also create a hook which will be
6509 executed whenever the program stops. See gdb.texinfo.
6513 We now deal with Cfront style name mangling, and can even extract type
6514 info from mangled symbols. GDB can automatically figure out which
6515 symbol mangling style your C++ compiler uses.
6517 Calling of methods and virtual functions has been improved as well.
6521 The crash that occured when debugging Sun Ansi-C compiled binaries is
6522 fixed. This was due to mishandling of the extra N_SO stabs output
6525 We also finally got Ultrix 4.2 running in house, and fixed core file
6526 support, with help from a dozen people on the net.
6528 John M. Farrell discovered that the reason that single-stepping was so
6529 slow on all of the Mips based platforms (primarily SGI and DEC) was
6530 that we were trying to demangle and lookup a symbol used for internal
6531 purposes on every instruction that was being stepped through. Changing
6532 the name of that symbol so that it couldn't be mistaken for a C++
6533 mangled symbol sped things up a great deal.
6535 Rich Pixley sped up symbol lookups in general by getting much smarter
6536 about when C++ symbol mangling is necessary. This should make symbol
6537 completion (TAB on the command line) much faster. It's not as fast as
6538 we'd like, but it's significantly faster than gdb-4.6.
6542 A new user controllable variable 'call_scratch_address' can
6543 specify the location of a scratch area to be used when GDB
6544 calls a function in the target. This is necessary because the
6545 usual method of putting the scratch area on the stack does not work
6546 in systems that have separate instruction and data spaces.
6548 We integrated changes to support the 29k UDI (Universal Debugger
6549 Interface), but discovered at the last minute that we didn't have all
6550 of the appropriate copyright paperwork. We are working with AMD to
6551 resolve this, and hope to have it available soon.
6555 We have sped up the remote serial line protocol, especially for targets
6556 with lots of registers. It now supports a new `expedited status' ('T')
6557 message which can be used in place of the existing 'S' status message.
6558 This allows the remote stub to send only the registers that GDB
6559 needs to make a quick decision about single-stepping or conditional
6560 breakpoints, eliminating the need to fetch the entire register set for
6561 each instruction being stepped through.
6563 The GDB remote serial protocol now implements a write-through cache for
6564 registers, only re-reading the registers if the target has run.
6566 There is also a new remote serial stub for SPARC processors. You can
6567 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6568 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6569 processor with a serial port.
6573 Configure.in files have become much easier to read and modify. A new
6574 `table driven' format makes it more obvious what configurations are
6575 supported, and what files each one uses.
6579 There is a new opcodes library which will eventually contain all of the
6580 disassembly routines and opcode tables. At present, it only contains
6581 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6582 disassembler (binutils/objdump) to share these routines.
6584 The libiberty library is now copylefted under the GNU Library General
6585 Public License. This allows more liberal use, and was done so libg++
6586 can use it. This makes no difference to GDB, since the Library License
6587 grants all the rights from the General Public License.
6591 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6592 reference to the stabs symbol info used by the debugger. It is (as far
6593 as we know) the only published document on this fascinating topic. We
6594 encourage you to read it, compare it to the stabs information on your
6595 system, and send improvements on the document in general (to
6596 bug-gdb@prep.ai.mit.edu).
6598 And, of course, many bugs have been fixed.
6601 *** Changes in GDB-4.6:
6603 * Better support for C++ function names
6605 GDB now accepts as input the "demangled form" of C++ overloaded function
6606 names and member function names, and can do command completion on such names
6607 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6608 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6609 Make use of command completion, it is your friend.
6611 GDB also now accepts a variety of C++ mangled symbol formats. They are
6612 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6613 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6614 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6615 for the list of formats.
6617 * G++ symbol mangling problem
6619 Recent versions of gcc have a bug in how they emit debugging information for
6620 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6621 directory) can be applied to gcc to fix the problem. Alternatively, if you
6622 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6623 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6624 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6627 * New 'maintenance' command
6629 All of the commands related to hacking GDB internals have been moved out of
6630 the main command set, and now live behind the 'maintenance' command. This
6631 can also be abbreviated as 'mt'. The following changes were made:
6633 dump-me -> maintenance dump-me
6634 info all-breakpoints -> maintenance info breakpoints
6635 printmsyms -> maintenance print msyms
6636 printobjfiles -> maintenance print objfiles
6637 printpsyms -> maintenance print psymbols
6638 printsyms -> maintenance print symbols
6640 The following commands are new:
6642 maintenance demangle Call internal GDB demangler routine to
6643 demangle a C++ link name and prints the result.
6644 maintenance print type Print a type chain for a given symbol
6646 * Change to .gdbinit file processing
6648 We now read the $HOME/.gdbinit file before processing the argv arguments
6649 (e.g. reading symbol files or core files). This allows global parameters to
6650 be set, which will apply during the symbol reading. The ./.gdbinit is still
6651 read after argv processing.
6653 * New hosts supported
6655 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6657 GNU/Linux support i386-unknown-linux or linux
6659 We are also including code to support the HP/PA running BSD and HPUX. This
6660 is almost guaranteed not to work, as we didn't have time to test or build it
6661 for this release. We are including it so that the more adventurous (or
6662 masochistic) of you can play with it. We also had major problems with the
6663 fact that the compiler that we got from HP doesn't support the -g option.
6666 * New targets supported
6668 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6670 * More smarts about finding #include files
6672 GDB now remembers the compilation directory for all include files, and for
6673 all files from which C is generated (like yacc and lex sources). This
6674 greatly improves GDB's ability to find yacc/lex sources, and include files,
6675 especially if you are debugging your program from a directory different from
6676 the one that contains your sources.
6678 We also fixed a bug which caused difficulty with listing and setting
6679 breakpoints in include files which contain C code. (In the past, you had to
6680 try twice in order to list an include file that you hadn't looked at before.)
6682 * Interesting infernals change
6684 GDB now deals with arbitrary numbers of sections, where the symbols for each
6685 section must be relocated relative to that section's landing place in the
6686 target's address space. This work was needed to support ELF with embedded
6687 stabs used by Solaris-2.0.
6689 * Bug fixes (of course!)
6691 There have been loads of fixes for the following things:
6692 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6693 i960, stabs, DOS(GO32), procfs, etc...
6695 See the ChangeLog for details.
6697 *** Changes in GDB-4.5:
6699 * New machines supported (host and target)
6701 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6703 SGI Irix-4.x mips-sgi-irix4 or iris4
6705 * New malloc package
6707 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6708 Mmalloc is capable of handling mutiple heaps of memory. It is also
6709 capable of saving a heap to a file, and then mapping it back in later.
6710 This can be used to greatly speedup the startup of GDB by using a
6711 pre-parsed symbol table which lives in a mmalloc managed heap. For
6712 more details, please read mmalloc/mmalloc.texi.
6716 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6717 'help info proc' for details.
6719 * MIPS ecoff symbol table format
6721 The code that reads MIPS symbol table format is now supported on all hosts.
6722 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6725 * File name changes for MS-DOS
6727 Many files in the config directories have been renamed to make it easier to
6728 support GDB on MS-DOSe systems (which have very restrictive file name
6729 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6730 environment) is close to working but has some remaining problems. Note
6731 that debugging of DOS programs is not supported, due to limitations
6732 in the ``operating system'', but it can be used to host cross-debugging.
6734 * Cross byte order fixes
6736 Many fixes have been made to support cross debugging of Sparc and MIPS
6737 targets from hosts whose byte order differs.
6739 * New -mapped and -readnow options
6741 If memory-mapped files are available on your system through the 'mmap'
6742 system call, you can use the -mapped option on the `file' or
6743 `symbol-file' commands to cause GDB to write the symbols from your
6744 program into a reusable file. If the program you are debugging is
6745 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6746 Future GDB debugging sessions will notice the presence of this file,
6747 and will quickly map in symbol information from it, rather than reading
6748 the symbol table from the executable program. Using the '-mapped'
6749 option in a GDB `file' or `symbol-file' command has the same effect as
6750 starting GDB with the '-mapped' command-line option.
6752 You can cause GDB to read the entire symbol table immediately by using
6753 the '-readnow' option with any of the commands that load symbol table
6754 information (or on the GDB command line). This makes the command
6755 slower, but makes future operations faster.
6757 The -mapped and -readnow options are typically combined in order to
6758 build a `fred.syms' file that contains complete symbol information.
6759 A simple GDB invocation to do nothing but build a `.syms' file for future
6762 gdb -batch -nx -mapped -readnow programname
6764 The `.syms' file is specific to the host machine on which GDB is run.
6765 It holds an exact image of GDB's internal symbol table. It cannot be
6766 shared across multiple host platforms.
6768 * longjmp() handling
6770 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6771 siglongjmp() without losing control. This feature has not yet been ported to
6772 all systems. It currently works on many 386 platforms, all MIPS-based
6773 platforms (SGI, DECstation, etc), and Sun3/4.
6777 Preliminary work has been put in to support the new Solaris OS from Sun. At
6778 this time, it can control and debug processes, but it is not capable of
6783 As always, many many bug fixes. The major areas were with g++, and mipsread.
6784 People using the MIPS-based platforms should experience fewer mysterious
6785 crashes and trashed symbol tables.
6787 *** Changes in GDB-4.4:
6789 * New machines supported (host and target)
6791 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6793 BSD Reno on Vax vax-dec-bsd
6794 Ultrix on Vax vax-dec-ultrix
6796 * New machines supported (target)
6798 AMD 29000 embedded, using EBMON a29k-none-none
6802 GDB continues to improve its handling of C++. `References' work better.
6803 The demangler has also been improved, and now deals with symbols mangled as
6804 per the Annotated C++ Reference Guide.
6806 GDB also now handles `stabs' symbol information embedded in MIPS
6807 `ecoff' symbol tables. Since the ecoff format was not easily
6808 extensible to handle new languages such as C++, this appeared to be a
6809 good way to put C++ debugging info into MIPS binaries. This option
6810 will be supported in the GNU C compiler, version 2, when it is
6813 * New features for SVR4
6815 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6816 shared libraries. Debugging dynamically linked programs should present
6817 only minor differences from debugging statically linked programs.
6819 The `info proc' command will print out information about any process
6820 on an SVR4 system (including the one you are debugging). At the moment,
6821 it prints the address mappings of the process.
6823 If you bring up GDB on another SVR4 system, please send mail to
6824 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6826 * Better dynamic linking support in SunOS
6828 Reading symbols from shared libraries which contain debugging symbols
6829 now works properly. However, there remain issues such as automatic
6830 skipping of `transfer vector' code during function calls, which
6831 make it harder to debug code in a shared library, than to debug the
6832 same code linked statically.
6836 GDB is now using the latest `getopt' routines from the FSF. This
6837 version accepts the -- prefix for options with long names. GDB will
6838 continue to accept the old forms (-option and +option) as well.
6839 Various single letter abbreviations for options have been explicity
6840 added to the option table so that they won't get overshadowed in the
6841 future by other options that begin with the same letter.
6845 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6846 Many assorted bugs have been handled. Many more remain to be handled.
6847 See the various ChangeLog files (primarily in gdb and bfd) for details.
6850 *** Changes in GDB-4.3:
6852 * New machines supported (host and target)
6854 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6855 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6856 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6858 * Almost SCO Unix support
6860 We had hoped to support:
6861 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6862 (except for core file support), but we discovered very late in the release
6863 that it has problems with process groups that render gdb unusable. Sorry
6864 about that. I encourage people to fix it and post the fixes.
6866 * Preliminary ELF and DWARF support
6868 GDB can read ELF object files on System V Release 4, and can handle
6869 debugging records for C, in DWARF format, in ELF files. This support
6870 is preliminary. If you bring up GDB on another SVR4 system, please
6871 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6876 GDB now uses the latest `readline' library. One user-visible change
6877 is that two tabs will list possible command completions, which previously
6878 required typing M-? (meta-question mark, or ESC ?).
6882 The `stepi' bug that many of you noticed has been squashed.
6883 Many bugs in C++ have been handled. Many more remain to be handled.
6884 See the various ChangeLog files (primarily in gdb and bfd) for details.
6886 * State of the MIPS world (in case you wondered):
6888 GDB can understand the symbol tables emitted by the compilers
6889 supplied by most vendors of MIPS-based machines, including DEC. These
6890 symbol tables are in a format that essentially nobody else uses.
6892 Some versions of gcc come with an assembler post-processor called
6893 mips-tfile. This program is required if you want to do source-level
6894 debugging of gcc-compiled programs. I believe FSF does not ship
6895 mips-tfile with gcc version 1, but it will eventually come with gcc
6898 Debugging of g++ output remains a problem. g++ version 1.xx does not
6899 really support it at all. (If you're lucky, you should be able to get
6900 line numbers and stack traces to work, but no parameters or local
6901 variables.) With some work it should be possible to improve the
6904 When gcc version 2 is released, you will have somewhat better luck.
6905 However, even then you will get confusing results for inheritance and
6908 We will eventually provide full debugging of g++ output on
6909 DECstations. This will probably involve some kind of stabs-in-ecoff
6910 encapulation, but the details have not been worked out yet.
6913 *** Changes in GDB-4.2:
6915 * Improved configuration
6917 Only one copy of `configure' exists now, and it is not self-modifying.
6918 Porting BFD is simpler.
6922 The `step' and `next' commands now only stop at the first instruction
6923 of a source line. This prevents the multiple stops that used to occur
6924 in switch statements, for-loops, etc. `Step' continues to stop if a
6925 function that has debugging information is called within the line.
6929 Lots of small bugs fixed. More remain.
6931 * New host supported (not target)
6933 Intel 386 PC clone running Mach i386-none-mach
6936 *** Changes in GDB-4.1:
6938 * Multiple source language support
6940 GDB now has internal scaffolding to handle several source languages.
6941 It determines the type of each source file from its filename extension,
6942 and will switch expression parsing and number formatting to match the
6943 language of the function in the currently selected stack frame.
6944 You can also specifically set the language to be used, with
6945 `set language c' or `set language modula-2'.
6949 GDB now has preliminary support for the GNU Modula-2 compiler,
6950 currently under development at the State University of New York at
6951 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6952 continue through the fall of 1991 and into 1992.
6954 Other Modula-2 compilers are currently not supported, and attempting to
6955 debug programs compiled with them will likely result in an error as the
6956 symbol table is read. Feel free to work on it, though!
6958 There are hooks in GDB for strict type checking and range checking,
6959 in the `Modula-2 philosophy', but they do not currently work.
6963 GDB can now write to executable and core files (e.g. patch
6964 a variable's value). You must turn this switch on, specify
6965 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6966 by assigning a new value to a variable. Modifications take
6969 * Automatic SunOS shared library reading
6971 When you run your program, GDB automatically determines where its
6972 shared libraries (if any) have been loaded, and reads their symbols.
6973 The `share' command is no longer needed. This also works when
6974 examining core files.
6978 You can specify the number of lines that the `list' command shows.
6981 * New machines supported (host and target)
6983 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6984 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6985 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6987 * New hosts supported (not targets)
6989 IBM RT/PC: romp-ibm-aix or rtpc
6991 * New targets supported (not hosts)
6993 AMD 29000 embedded with COFF a29k-none-coff
6994 AMD 29000 embedded with a.out a29k-none-aout
6995 Ultracomputer remote kernel debug a29k-nyu-kern
6997 * New remote interfaces
7003 *** Changes in GDB-4.0:
7007 Wide output is wrapped at good places to make the output more readable.
7009 Gdb now supports cross-debugging from a host machine of one type to a
7010 target machine of another type. Communication with the target system
7011 is over serial lines. The ``target'' command handles connecting to the
7012 remote system; the ``load'' command will download a program into the
7013 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7014 also supports debugging of realtime processes running under VxWorks,
7015 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7016 stub on the target system.
7018 New CPUs supported include the AMD 29000 and Intel 960.
7020 GDB now reads object files and symbol tables via a ``binary file''
7021 library, which allows a single copy of GDB to debug programs of multiple
7022 object file types such as a.out and coff.
7024 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7025 refcard.dvi and refcard.ps are available to format it).
7028 * Control-Variable user interface simplified
7030 All variables that control the operation of the debugger can be set
7031 by the ``set'' command, and displayed by the ``show'' command.
7033 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7034 ``Show prompt'' produces the response:
7035 Gdb's prompt is new-gdb=>.
7037 What follows are the NEW set commands. The command ``help set'' will
7038 print a complete list of old and new set commands. ``help set FOO''
7039 will give a longer description of the variable FOO. ``show'' will show
7040 all of the variable descriptions and their current settings.
7042 confirm on/off: Enables warning questions for operations that are
7043 hard to recover from, e.g. rerunning the program while
7044 it is already running. Default is ON.
7046 editing on/off: Enables EMACS style command line editing
7047 of input. Previous lines can be recalled with
7048 control-P, the current line can be edited with control-B,
7049 you can search for commands with control-R, etc.
7052 history filename NAME: NAME is where the gdb command history
7053 will be stored. The default is .gdb_history,
7054 or the value of the environment variable
7057 history size N: The size, in commands, of the command history. The
7058 default is 256, or the value of the environment variable
7061 history save on/off: If this value is set to ON, the history file will
7062 be saved after exiting gdb. If set to OFF, the
7063 file will not be saved. The default is OFF.
7065 history expansion on/off: If this value is set to ON, then csh-like
7066 history expansion will be performed on
7067 command line input. The default is OFF.
7069 radix N: Sets the default radix for input and output. It can be set
7070 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7071 in the current radix, so "set radix 10" is always a no-op.
7073 height N: This integer value is the number of lines on a page. Default
7074 is 24, the current `stty rows'' setting, or the ``li#''
7075 setting from the termcap entry matching the environment
7078 width N: This integer value is the number of characters on a line.
7079 Default is 80, the current `stty cols'' setting, or the ``co#''
7080 setting from the termcap entry matching the environment
7083 Note: ``set screensize'' is obsolete. Use ``set height'' and
7084 ``set width'' instead.
7086 print address on/off: Print memory addresses in various command displays,
7087 such as stack traces and structure values. Gdb looks
7088 more ``symbolic'' if you turn this off; it looks more
7089 ``machine level'' with it on. Default is ON.
7091 print array on/off: Prettyprint arrays. New convenient format! Default
7094 print demangle on/off: Print C++ symbols in "source" form if on,
7097 print asm-demangle on/off: Same, for assembler level printouts
7100 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7103 * Support for Epoch Environment.
7105 The epoch environment is a version of Emacs v18 with windowing. One
7106 new command, ``inspect'', is identical to ``print'', except that if you
7107 are running in the epoch environment, the value is printed in its own
7111 * Support for Shared Libraries
7113 GDB can now debug programs and core files that use SunOS shared libraries.
7114 Symbols from a shared library cannot be referenced
7115 before the shared library has been linked with the program (this
7116 happens after you type ``run'' and before the function main() is entered).
7117 At any time after this linking (including when examining core files
7118 from dynamically linked programs), gdb reads the symbols from each
7119 shared library when you type the ``sharedlibrary'' command.
7120 It can be abbreviated ``share''.
7122 sharedlibrary REGEXP: Load shared object library symbols for files
7123 matching a unix regular expression. No argument
7124 indicates to load symbols for all shared libraries.
7126 info sharedlibrary: Status of loaded shared libraries.
7131 A watchpoint stops execution of a program whenever the value of an
7132 expression changes. Checking for this slows down execution
7133 tremendously whenever you are in the scope of the expression, but is
7134 quite useful for catching tough ``bit-spreader'' or pointer misuse
7135 problems. Some machines such as the 386 have hardware for doing this
7136 more quickly, and future versions of gdb will use this hardware.
7138 watch EXP: Set a watchpoint (breakpoint) for an expression.
7140 info watchpoints: Information about your watchpoints.
7142 delete N: Deletes watchpoint number N (same as breakpoints).
7143 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7144 enable N: Re-enables watchpoint number N (same as breakpoints).
7147 * C++ multiple inheritance
7149 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7152 * C++ exception handling
7154 Gdb now supports limited C++ exception handling. Besides the existing
7155 ability to breakpoint on an exception handler, gdb can breakpoint on
7156 the raising of an exception (before the stack is peeled back to the
7159 catch FOO: If there is a FOO exception handler in the dynamic scope,
7160 set a breakpoint to catch exceptions which may be raised there.
7161 Multiple exceptions (``catch foo bar baz'') may be caught.
7163 info catch: Lists all exceptions which may be caught in the
7164 current stack frame.
7167 * Minor command changes
7169 The command ``call func (arg, arg, ...)'' now acts like the print
7170 command, except it does not print or save a value if the function's result
7171 is void. This is similar to dbx usage.
7173 The ``up'' and ``down'' commands now always print the frame they end up
7174 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7175 frames without printing.
7177 * New directory command
7179 'dir' now adds directories to the FRONT of the source search path.
7180 The path starts off empty. Source files that contain debug information
7181 about the directory in which they were compiled can be found even
7182 with an empty path; Sun CC and GCC include this information. If GDB can't
7183 find your source file in the current directory, type "dir .".
7185 * Configuring GDB for compilation
7187 For normal use, type ``./configure host''. See README or gdb.texinfo
7190 GDB now handles cross debugging. If you are remotely debugging between
7191 two different machines, type ``./configure host -target=targ''.
7192 Host is the machine where GDB will run; targ is the machine
7193 where the program that you are debugging will run.