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*
99 GNU/Linux/RISC-V riscv*-*-linux*
101 CSKY GNU/LINUX csky*-*-linux
102 FreeBSD/riscv riscv*-*-freebsd*
106 ** The gdb.Inferior type has a new 'progspace' property, which is the program
107 space associated to that inferior.
109 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
110 of objfiles associated to that program space.
112 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
113 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
116 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
117 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
118 correct and did not work properly.
124 Enable or disable the undefined behavior sanitizer. Release
125 versions of GDB disable this by default if it is available, but
126 development versions enable it. Enabling this can cause a
127 performance penalty. The undefined behavior sanitizer was first
128 introduced in GCC 4.9.
130 *** Changes in GDB 8.2
132 * The 'set disassembler-options' command now supports specifying options
135 * The 'symbol-file' command now accepts an '-o' option to add a relative
136 offset to all sections.
138 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
139 a relative offset to all sections, but it allows to override the load
140 address of individual sections using '-s'.
142 * The 'add-symbol-file' command no longer requires the second argument
143 (address of the text section).
145 * The endianness used with the 'set endian auto' mode in the absence of
146 an executable selected for debugging is now the last endianness chosen
147 either by one of the 'set endian big' and 'set endian little' commands
148 or by inferring from the last executable used, rather than the startup
151 * The pager now allows a "c" response, meaning to disable the pager
152 for the rest of the current command.
154 * The commands 'info variables/functions/types' now show the source line
155 numbers of symbol definitions when available.
157 * 'info proc' now works on running processes on FreeBSD systems and core
158 files created on FreeBSD systems.
160 * C expressions can now use _Alignof, and C++ expressions can now use
163 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
164 the vector length while the process is running.
170 Control display of debugging info regarding the FreeBSD native target.
172 set|show varsize-limit
173 This new setting allows the user to control the maximum size of Ada
174 objects being printed when those objects have a variable type,
175 instead of that maximum size being hardcoded to 65536 bytes.
177 set|show record btrace cpu
178 Controls the processor to be used for enabling errata workarounds for
181 maint check libthread-db
182 Run integrity checks on the current inferior's thread debugging
185 maint set check-libthread-db (on|off)
186 maint show check-libthread-db
187 Control whether to run integrity checks on inferior specific thread
188 debugging libraries as they are loaded. The default is not to
193 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
195 ** The commands attached to a breakpoint can be set by assigning to
196 the breakpoint's "commands" field.
198 ** gdb.execute can now execute multi-line gdb commands.
200 ** The new functions gdb.convenience_variable and
201 gdb.set_convenience_variable can be used to get and set the value
202 of convenience variables.
204 ** A gdb.Parameter will no longer print the "set" help text on an
205 ordinary "set"; instead by default a "set" will be silent unless
206 the get_set_string method returns a non-empty string.
210 RiscV ELF riscv*-*-elf
212 * Removed targets and native configurations
214 m88k running OpenBSD m88*-*-openbsd*
215 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
216 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
217 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
219 * Aarch64/Linux hardware watchpoints improvements
221 Hardware watchpoints on unaligned addresses are now properly
222 supported when running Linux kernel 4.10 or higher: read and access
223 watchpoints are no longer spuriously missed, and all watchpoints
224 lengths between 1 and 8 bytes are supported. On older kernels,
225 watchpoints set on unaligned addresses are no longer missed, with
226 the tradeoff that there is a possibility of false hits being
231 --enable-codesign=CERT
232 This can be used to invoke "codesign -s CERT" after building gdb.
233 This option is useful on macOS, where code signing is required for
234 gdb to work properly.
236 --disable-gdbcli has been removed
237 This is now silently accepted, but does nothing.
239 *** Changes in GDB 8.1
241 * GDB now supports dynamically creating arbitrary register groups specified
242 in XML target descriptions. This allows for finer grain grouping of
243 registers on systems with a large amount of registers.
245 * The 'ptype' command now accepts a '/o' flag, which prints the
246 offsets and sizes of fields in a struct, like the pahole(1) tool.
248 * New "--readnever" command line option instructs GDB to not read each
249 symbol file's symbolic debug information. This makes startup faster
250 but at the expense of not being able to perform symbolic debugging.
251 This option is intended for use cases where symbolic debugging will
252 not be used, e.g., when you only need to dump the debuggee's core.
254 * GDB now uses the GNU MPFR library, if available, to emulate target
255 floating-point arithmetic during expression evaluation when the target
256 uses different floating-point formats than the host. At least version
257 3.1 of GNU MPFR is required.
259 * GDB now supports access to the guarded-storage-control registers and the
260 software-based guarded-storage broadcast control registers on IBM z14.
262 * On Unix systems, GDB now supports transmitting environment variables
263 that are to be set or unset to GDBserver. These variables will
264 affect the environment to be passed to the remote inferior.
266 To inform GDB of environment variables that are to be transmitted to
267 GDBserver, use the "set environment" command. Only user set
268 environment variables are sent to GDBserver.
270 To inform GDB of environment variables that are to be unset before
271 the remote inferior is started by the GDBserver, use the "unset
272 environment" command.
274 * Completion improvements
276 ** GDB can now complete function parameters in linespecs and
277 explicit locations without quoting. When setting breakpoints,
278 quoting around functions names to help with TAB-completion is
279 generally no longer necessary. For example, this now completes
282 (gdb) b function(in[TAB]
283 (gdb) b function(int)
285 Related, GDB is no longer confused with completing functions in
286 C++ anonymous namespaces:
289 (gdb) b (anonymous namespace)::[TAB][TAB]
290 (anonymous namespace)::a_function()
291 (anonymous namespace)::b_function()
293 ** GDB now has much improved linespec and explicit locations TAB
294 completion support, that better understands what you're
295 completing and offers better suggestions. For example, GDB no
296 longer offers data symbols as possible completions when you're
297 setting a breakpoint.
299 ** GDB now TAB-completes label symbol names.
301 ** The "complete" command now mimics TAB completion accurately.
303 * New command line options (gcore)
306 Dump all memory mappings.
308 * Breakpoints on C++ functions are now set on all scopes by default
310 By default, breakpoints on functions/methods are now interpreted as
311 specifying all functions with the given name ignoring missing
312 leading scopes (namespaces and classes).
314 For example, assuming a C++ program with symbols named:
319 both commands "break func()" and "break B::func()" set a breakpoint
322 You can use the new flag "-qualified" to override this. This makes
323 GDB interpret the specified function name as a complete
324 fully-qualified name instead. For example, using the same C++
325 program, the "break -q B::func" command sets a breakpoint on
326 "B::func", only. A parameter has been added to the Python
327 gdb.Breakpoint constructor to achieve the same result when creating
328 a breakpoint from Python.
330 * Breakpoints on functions marked with C++ ABI tags
332 GDB can now set breakpoints on functions marked with C++ ABI tags
333 (e.g., [abi:cxx11]). See here for a description of ABI tags:
334 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
336 Functions with a C++11 abi tag are demangled/displayed like this:
338 function[abi:cxx11](int)
341 You can now set a breakpoint on such functions simply as if they had
344 (gdb) b function(int)
346 Or if you need to disambiguate between tags, like:
348 (gdb) b function[abi:other_tag](int)
350 Tab completion was adjusted accordingly as well.
354 ** New events gdb.new_inferior, gdb.inferior_deleted, and
355 gdb.new_thread are emitted. See the manual for further
356 description of these.
358 ** A new function, "gdb.rbreak" has been added to the Python API.
359 This function allows the setting of a large number of breakpoints
360 via a regex pattern in Python. See the manual for further details.
362 ** Python breakpoints can now accept explicit locations. See the
363 manual for a further description of this feature.
366 * New features in the GDB remote stub, GDBserver
368 ** GDBserver is now able to start inferior processes with a
369 specified initial working directory.
371 The user can set the desired working directory to be used from
372 GDB using the new "set cwd" command.
374 ** New "--selftest" command line option runs some GDBserver self
375 tests. These self tests are disabled in releases.
377 ** On Unix systems, GDBserver now does globbing expansion and variable
378 substitution in inferior command line arguments.
380 This is done by starting inferiors using a shell, like GDB does.
381 See "set startup-with-shell" in the user manual for how to disable
382 this from GDB when using "target extended-remote". When using
383 "target remote", you can disable the startup with shell by using the
384 new "--no-startup-with-shell" GDBserver command line option.
386 ** On Unix systems, GDBserver now supports receiving environment
387 variables that are to be set or unset from GDB. These variables
388 will affect the environment to be passed to the inferior.
390 * When catching an Ada exception raised with a message, GDB now prints
391 the message in the catchpoint hit notification. In GDB/MI mode, that
392 information is provided as an extra field named "exception-message"
393 in the *stopped notification.
395 * Trait objects can now be inspected When debugging Rust code. This
396 requires compiler support which will appear in Rust 1.24.
400 QEnvironmentHexEncoded
401 Inform GDBserver of an environment variable that is to be passed to
402 the inferior when starting it.
405 Inform GDBserver of an environment variable that is to be unset
406 before starting the remote inferior.
409 Inform GDBserver that the environment should be reset (i.e.,
410 user-set environment variables should be unset).
413 Indicates whether the inferior must be started with a shell or not.
416 Tell GDBserver that the inferior to be started should use a specific
419 * The "maintenance print c-tdesc" command now takes an optional
420 argument which is the file name of XML target description.
422 * The "maintenance selftest" command now takes an optional argument to
423 filter the tests to be run.
425 * The "enable", and "disable" commands now accept a range of
426 breakpoint locations, e.g. "enable 1.3-5".
431 Set and show the current working directory for the inferior.
434 Set and show compilation command used for compiling and injecting code
435 with the 'compile' commands.
437 set debug separate-debug-file
438 show debug separate-debug-file
439 Control the display of debug output about separate debug file search.
441 set dump-excluded-mappings
442 show dump-excluded-mappings
443 Control whether mappings marked with the VM_DONTDUMP flag should be
444 dumped when generating a core file.
447 List the registered selftests.
450 Start the debugged program stopping at the first instruction.
453 Control display of debugging messages related to OpenRISC targets.
455 set|show print type nested-type-limit
456 Set and show the limit of nesting level for nested types that the
457 type printer will show.
459 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
462 * Safer/improved support for debugging with no debug info
464 GDB no longer assumes functions with no debug information return
467 This means that GDB now refuses to call such functions unless you
468 tell it the function's type, by either casting the call to the
469 declared return type, or by casting the function to a function
470 pointer of the right type, and calling that:
472 (gdb) p getenv ("PATH")
473 'getenv' has unknown return type; cast the call to its declared return type
474 (gdb) p (char *) getenv ("PATH")
475 $1 = 0x7fffffffe "/usr/local/bin:/"...
476 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
477 $2 = 0x7fffffffe "/usr/local/bin:/"...
479 Similarly, GDB no longer assumes that global variables with no debug
480 info have type 'int', and refuses to print the variable's value
481 unless you tell it the variable's type:
484 'var' has unknown type; cast it to its declared type
488 * New native configurations
490 FreeBSD/aarch64 aarch64*-*-freebsd*
491 FreeBSD/arm arm*-*-freebsd*
495 FreeBSD/aarch64 aarch64*-*-freebsd*
496 FreeBSD/arm arm*-*-freebsd*
497 OpenRISC ELF or1k*-*-elf
499 * Removed targets and native configurations
501 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
503 *** Changes in GDB 8.0
505 * GDB now supports access to the PKU register on GNU/Linux. The register is
506 added by the Memory Protection Keys for Userspace feature which will be
507 available in future Intel CPUs.
509 * GDB now supports C++11 rvalue references.
513 ** New functions to start, stop and access a running btrace recording.
514 ** Rvalue references are now supported in gdb.Type.
516 * GDB now supports recording and replaying rdrand and rdseed Intel 64
519 * Building GDB and GDBserver now requires a C++11 compiler.
521 For example, GCC 4.8 or later.
523 It is no longer possible to build GDB or GDBserver with a C
524 compiler. The --disable-build-with-cxx configure option has been
527 * Building GDB and GDBserver now requires GNU make >= 3.81.
529 It is no longer supported to build GDB or GDBserver with another
530 implementation of the make program or an earlier version of GNU make.
532 * Native debugging on MS-Windows supports command-line redirection
534 Command-line arguments used for starting programs on MS-Windows can
535 now include redirection symbols supported by native Windows shells,
536 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
537 as "run", "start", and "set args", as well as the corresponding MI
540 * Support for thread names on MS-Windows.
542 GDB now catches and handles the special exception that programs
543 running on MS-Windows use to assign names to threads in the
546 * Support for Java programs compiled with gcj has been removed.
548 * User commands now accept an unlimited number of arguments.
549 Previously, only up to 10 was accepted.
551 * The "eval" command now expands user-defined command arguments.
553 This makes it easier to process a variable number of arguments:
558 eval "print $arg%d", $i
563 * Target descriptions can now describe registers for sparc32 and sparc64.
565 * GDB now supports DWARF version 5 (debug information format).
566 Its .debug_names index is not yet supported.
568 * New native configurations
570 FreeBSD/mips mips*-*-freebsd
574 Synopsys ARC arc*-*-elf32
575 FreeBSD/mips mips*-*-freebsd
577 * Removed targets and native configurations
579 Alpha running FreeBSD alpha*-*-freebsd*
580 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
585 Erases all the flash memory regions reported by the target.
587 maint print arc arc-instruction address
588 Print internal disassembler information about instruction at a given address.
592 set disassembler-options
593 show disassembler-options
594 Controls the passing of target specific information to the disassembler.
595 If it is necessary to specify more than one disassembler option then
596 multiple options can be placed together into a comma separated list.
597 The default value is the empty string. Currently, the only supported
598 targets are ARM, PowerPC and S/390.
603 Erases all the flash memory regions reported by the target. This is
604 equivalent to the CLI command flash-erase.
606 -file-list-shared-libraries
607 List the shared libraries in the program. This is
608 equivalent to the CLI command "info shared".
611 Catchpoints stopping the program when Ada exceptions are
612 handled. This is equivalent to the CLI command "catch handlers".
614 *** Changes in GDB 7.12
616 * GDB and GDBserver now build with a C++ compiler by default.
618 The --enable-build-with-cxx configure option is now enabled by
619 default. One must now explicitly configure with
620 --disable-build-with-cxx in order to build with a C compiler. This
621 option will be removed in a future release.
623 * GDBserver now supports recording btrace without maintaining an active
626 * GDB now supports a negative repeat count in the 'x' command to examine
627 memory backward from the given address. For example:
630 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
631 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
632 (gdb) x/-5i 0x0000000000400580
633 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
634 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
635 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
636 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
637 0x40057b <main(int, char**)+25>:
638 callq 0x400536 <Func1(int, char const*)>
640 * Fortran: Support structures with fields of dynamic types and
641 arrays of dynamic types.
643 * The symbol dumping maintenance commands have new syntax.
644 maint print symbols [-pc address] [--] [filename]
645 maint print symbols [-objfile objfile] [-source source] [--] [filename]
646 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
647 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
648 maint print msymbols [-objfile objfile] [--] [filename]
650 * GDB now supports multibit bitfields and enums in target register
653 * New Python-based convenience function $_as_string(val), which returns
654 the textual representation of a value. This function is especially
655 useful to obtain the text label of an enum value.
657 * Intel MPX bound violation handling.
659 Segmentation faults caused by a Intel MPX boundary violation
660 now display the kind of violation (upper or lower), the memory
661 address accessed and the memory bounds, along with the usual
662 signal received and code location.
666 Program received signal SIGSEGV, Segmentation fault
667 Upper bound violation while accessing address 0x7fffffffc3b3
668 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
669 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
671 * Rust language support.
672 GDB now supports debugging programs written in the Rust programming
673 language. See https://www.rust-lang.org/ for more information about
676 * Support for running interpreters on specified input/output devices
678 GDB now supports a new mechanism that allows frontends to provide
679 fully featured GDB console views, as a better alternative to
680 building such views on top of the "-interpreter-exec console"
681 command. See the new "new-ui" command below. With that command,
682 frontends can now start GDB in the traditional command-line mode
683 running in an embedded terminal emulator widget, and create a
684 separate MI interpreter running on a specified i/o device. In this
685 way, GDB handles line editing, history, tab completion, etc. in the
686 console all by itself, and the GUI uses the separate MI interpreter
687 for its own control and synchronization, invisible to the command
690 * The "catch syscall" command catches groups of related syscalls.
692 The "catch syscall" command now supports catching a group of related
693 syscalls using the 'group:' or 'g:' prefix.
698 skip -gfile file-glob-pattern
699 skip -function function
700 skip -rfunction regular-expression
701 A generalized form of the skip command, with new support for
702 glob-style file names and regular expressions for function names.
703 Additionally, a file spec and a function spec may now be combined.
705 maint info line-table REGEXP
706 Display the contents of GDB's internal line table data struture.
709 Run any GDB unit tests that were compiled in.
712 Start a new user interface instance running INTERP as interpreter,
713 using the TTY file for input/output.
717 ** gdb.Breakpoint objects have a new attribute "pending", which
718 indicates whether the breakpoint is pending.
719 ** Three new breakpoint-related events have been added:
720 gdb.breakpoint_created, gdb.breakpoint_modified, and
721 gdb.breakpoint_deleted.
724 Signal ("set") the given MS-Windows event object. This is used in
725 conjunction with the Windows JIT debugging (AeDebug) support, where
726 the OS suspends a crashing process until a debugger can attach to
727 it. Resuming the crashing process, in order to debug it, is done by
730 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
731 was added in GDBserver, including JIT compiling fast tracepoint's
732 conditional expression bytecode into native code.
734 * Support for various remote target protocols and ROM monitors has
737 target m32rsdi Remote M32R debugging over SDI
738 target mips MIPS remote debugging protocol
739 target pmon PMON ROM monitor
740 target ddb NEC's DDB variant of PMON for Vr4300
741 target rockhopper NEC RockHopper variant of PMON
742 target lsi LSI variant of PMO
744 * Support for tracepoints and fast tracepoints on powerpc-linux,
745 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
746 including JIT compiling fast tracepoint's conditional expression
747 bytecode into native code.
749 * MI async record =record-started now includes the method and format used for
750 recording. For example:
752 =record-started,thread-group="i1",method="btrace",format="bts"
754 * MI async record =thread-selected now includes the frame field. For example:
756 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
760 Andes NDS32 nds32*-*-elf
762 *** Changes in GDB 7.11
764 * GDB now supports debugging kernel-based threads on FreeBSD.
766 * Per-inferior thread numbers
768 Thread numbers are now per inferior instead of global. If you're
769 debugging multiple inferiors, GDB displays thread IDs using a
770 qualified INF_NUM.THR_NUM form. For example:
774 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
775 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
776 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
777 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
779 As consequence, thread numbers as visible in the $_thread
780 convenience variable and in Python's InferiorThread.num attribute
781 are no longer unique between inferiors.
783 GDB now maintains a second thread ID per thread, referred to as the
784 global thread ID, which is the new equivalent of thread numbers in
785 previous releases. See also $_gthread below.
787 For backwards compatibility, MI's thread IDs always refer to global
790 * Commands that accept thread IDs now accept the qualified
791 INF_NUM.THR_NUM form as well. For example:
794 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
797 * In commands that accept a list of thread IDs, you can now refer to
798 all threads of an inferior using a star wildcard. GDB accepts
799 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
800 refer to all threads of the current inferior. For example, "info
803 * You can use "info threads -gid" to display the global thread ID of
806 * The new convenience variable $_gthread holds the global number of
809 * The new convenience variable $_inferior holds the number of the
812 * GDB now displays the ID and name of the thread that hit a breakpoint
813 or received a signal, if your program is multi-threaded. For
816 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
817 Thread 1 "main" received signal SIGINT, Interrupt.
819 * Record btrace now supports non-stop mode.
821 * Support for tracepoints on aarch64-linux was added in GDBserver.
823 * The 'record instruction-history' command now indicates speculative execution
824 when using the Intel Processor Trace recording format.
826 * GDB now allows users to specify explicit locations, bypassing
827 the linespec parser. This feature is also available to GDB/MI
830 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
831 GDB now is able to debug both AArch64 applications and ARM applications
834 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
835 including JIT compiling fast tracepoint's conditional expression bytecode
838 * GDB now supports displaced stepping on AArch64 GNU/Linux.
840 * "info threads", "info inferiors", "info display", "info checkpoints"
841 and "maint info program-spaces" now list the corresponding items in
842 ascending ID order, for consistency with all other "info" commands.
844 * In Ada, the overloads selection menu has been enhanced to display the
845 parameter types and the return types for the matching overloaded subprograms.
849 maint set target-non-stop (on|off|auto)
850 maint show target-non-stop
851 Control whether GDB targets always operate in non-stop mode even if
852 "set non-stop" is "off". The default is "auto", meaning non-stop
853 mode is enabled if supported by the target.
855 maint set bfd-sharing
856 maint show bfd-sharing
857 Control the reuse of bfd objects.
861 Control display of debugging info regarding bfd caching.
865 Control display of debugging info regarding FreeBSD threads.
867 set remote multiprocess-extensions-packet
868 show remote multiprocess-extensions-packet
869 Set/show the use of the remote protocol multiprocess extensions.
871 set remote thread-events
872 show remote thread-events
873 Set/show the use of thread create/exit events.
875 set ada print-signatures on|off
876 show ada print-signatures"
877 Control whether parameter types and return types are displayed in overloads
878 selection menus. It is activaled (@code{on}) by default.
882 Controls the maximum size of memory, in bytes, that GDB will
883 allocate for value contents. Prevents incorrect programs from
884 causing GDB to allocate overly large buffers. Default is 64k.
886 * The "disassemble" command accepts a new modifier: /s.
887 It prints mixed source+disassembly like /m with two differences:
888 - disassembled instructions are now printed in program order, and
889 - and source for all relevant files is now printed.
890 The "/m" option is now considered deprecated: its "source-centric"
891 output hasn't proved useful in practice.
893 * The "record instruction-history" command accepts a new modifier: /s.
894 It behaves exactly like /m and prints mixed source+disassembly.
896 * The "set scheduler-locking" command supports a new mode "replay".
897 It behaves like "off" in record mode and like "on" in replay mode.
899 * Support for various ROM monitors has been removed:
901 target dbug dBUG ROM monitor for Motorola ColdFire
902 target picobug Motorola picobug monitor
903 target dink32 DINK32 ROM monitor for PowerPC
904 target m32r Renesas M32R/D ROM monitor
905 target mon2000 mon2000 ROM monitor
906 target ppcbug PPCBUG ROM monitor for PowerPC
908 * Support for reading/writing memory and extracting values on architectures
909 whose memory is addressable in units of any integral multiple of 8 bits.
912 Allows to break when an Ada exception is handled.
917 Indicates that an exec system call was executed.
919 exec-events feature in qSupported
920 The qSupported packet allows GDB to request support for exec
921 events using the new 'gdbfeature' exec-event, and the qSupported
922 response can contain the corresponding 'stubfeature'. Set and
923 show commands can be used to display whether these features are enabled.
926 Equivalent to interrupting with the ^C character, but works in
929 thread created stop reason (T05 create:...)
930 Indicates that the thread was just created and is stopped at entry.
932 thread exit stop reply (w exitcode;tid)
933 Indicates that the thread has terminated.
936 Enables/disables thread create and exit event reporting. For
937 example, this is used in non-stop mode when GDB stops a set of
938 threads and synchronously waits for the their corresponding stop
939 replies. Without exit events, if one of the threads exits, GDB
940 would hang forever not knowing that it should no longer expect a
941 stop for that same thread.
944 Indicates that there are no resumed threads left in the target (all
945 threads are stopped). The remote stub reports support for this stop
946 reply to GDB's qSupported query.
949 Enables/disables catching syscalls from the inferior process.
950 The remote stub reports support for this packet to GDB's qSupported query.
952 syscall_entry stop reason
953 Indicates that a syscall was just called.
955 syscall_return stop reason
956 Indicates that a syscall just returned.
958 * Extended-remote exec events
960 ** GDB now has support for exec events on extended-remote Linux targets.
961 For such targets with Linux kernels 2.5.46 and later, this enables
962 follow-exec-mode and exec catchpoints.
964 set remote exec-event-feature-packet
965 show remote exec-event-feature-packet
966 Set/show the use of the remote exec event feature.
968 * Thread names in remote protocol
970 The reply to qXfer:threads:read may now include a name attribute for each
973 * Target remote mode fork and exec events
975 ** GDB now has support for fork and exec events on target remote mode
976 Linux targets. For such targets with Linux kernels 2.5.46 and later,
977 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
978 fork and exec catchpoints.
980 * Remote syscall events
982 ** GDB now has support for catch syscall on remote Linux targets,
983 currently enabled on x86/x86_64 architectures.
985 set remote catch-syscall-packet
986 show remote catch-syscall-packet
987 Set/show the use of the remote catch syscall feature.
991 ** The -var-set-format command now accepts the zero-hexadecimal
992 format. It outputs data in hexadecimal format with zero-padding on the
997 ** gdb.InferiorThread objects have a new attribute "global_num",
998 which refers to the thread's global thread ID. The existing
999 "num" attribute now refers to the thread's per-inferior number.
1000 See "Per-inferior thread numbers" above.
1001 ** gdb.InferiorThread objects have a new attribute "inferior", which
1002 is the Inferior object the thread belongs to.
1004 *** Changes in GDB 7.10
1006 * Support for process record-replay and reverse debugging on aarch64*-linux*
1007 targets has been added. GDB now supports recording of A64 instruction set
1008 including advance SIMD instructions.
1010 * Support for Sun's version of the "stabs" debug file format has been removed.
1012 * GDB now honors the content of the file /proc/PID/coredump_filter
1013 (PID is the process ID) on GNU/Linux systems. This file can be used
1014 to specify the types of memory mappings that will be included in a
1015 corefile. For more information, please refer to the manual page of
1016 "core(5)". GDB also has a new command: "set use-coredump-filter
1017 on|off". It allows to set whether GDB will read the content of the
1018 /proc/PID/coredump_filter file when generating a corefile.
1020 * The "info os" command on GNU/Linux can now display information on
1022 "info os cpus" Listing of all cpus/cores on the system
1024 * GDB has two new commands: "set serial parity odd|even|none" and
1025 "show serial parity". These allows to set or show parity for the
1028 * The "info source" command now displays the producer string if it was
1029 present in the debug info. This typically includes the compiler version
1030 and may include things like its command line arguments.
1032 * The "info dll", an alias of the "info sharedlibrary" command,
1033 is now available on all platforms.
1035 * Directory names supplied to the "set sysroot" commands may be
1036 prefixed with "target:" to tell GDB to access shared libraries from
1037 the target system, be it local or remote. This replaces the prefix
1038 "remote:". The default sysroot has been changed from "" to
1039 "target:". "remote:" is automatically converted to "target:" for
1040 backward compatibility.
1042 * The system root specified by "set sysroot" will be prepended to the
1043 filename of the main executable (if reported to GDB as absolute by
1044 the operating system) when starting processes remotely, and when
1045 attaching to already-running local or remote processes.
1047 * GDB now supports automatic location and retrieval of executable
1048 files from remote targets. Remote debugging can now be initiated
1049 using only a "target remote" or "target extended-remote" command
1050 (no "set sysroot" or "file" commands are required). See "New remote
1053 * The "dump" command now supports verilog hex format.
1055 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1057 * On GNU/Linux, GDB and gdbserver are now able to access executable
1058 and shared library files without a "set sysroot" command when
1059 attaching to processes running in different mount namespaces from
1060 the debugger. This makes it possible to attach to processes in
1061 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1062 See "New remote packets" below.
1064 * The "tui reg" command now provides completion for all of the
1065 available register groups, including target specific groups.
1067 * The HISTSIZE environment variable is no longer read when determining
1068 the size of GDB's command history. GDB now instead reads the dedicated
1069 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1070 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1075 ** Memory ports can now be unbuffered.
1079 ** gdb.Objfile objects have a new attribute "username",
1080 which is the name of the objfile as specified by the user,
1081 without, for example, resolving symlinks.
1082 ** You can now write frame unwinders in Python.
1083 ** gdb.Type objects have a new method "optimized_out",
1084 returning optimized out gdb.Value instance of this type.
1085 ** gdb.Value objects have new methods "reference_value" and
1086 "const_value" which return a reference to the value and a
1087 "const" version of the value respectively.
1091 maint print symbol-cache
1092 Print the contents of the symbol cache.
1094 maint print symbol-cache-statistics
1095 Print statistics of symbol cache usage.
1097 maint flush-symbol-cache
1098 Flush the contents of the symbol cache.
1102 Start branch trace recording using Branch Trace Store (BTS) format.
1105 Evaluate expression by using the compiler and print result.
1109 Explicit commands for enabling and disabling tui mode.
1112 set mpx bound on i386 and amd64
1113 Support for bound table investigation on Intel MPX enabled applications.
1117 Start branch trace recording using Intel Processor Trace format.
1120 Print information about branch tracing internals.
1122 maint btrace packet-history
1123 Print the raw branch tracing data.
1125 maint btrace clear-packet-history
1126 Discard the stored raw branch tracing data.
1129 Discard all branch tracing data. It will be fetched and processed
1130 anew by the next "record" command.
1135 Renamed from "set debug dwarf2-die".
1136 show debug dwarf-die
1137 Renamed from "show debug dwarf2-die".
1139 set debug dwarf-read
1140 Renamed from "set debug dwarf2-read".
1141 show debug dwarf-read
1142 Renamed from "show debug dwarf2-read".
1144 maint set dwarf always-disassemble
1145 Renamed from "maint set dwarf2 always-disassemble".
1146 maint show dwarf always-disassemble
1147 Renamed from "maint show dwarf2 always-disassemble".
1149 maint set dwarf max-cache-age
1150 Renamed from "maint set dwarf2 max-cache-age".
1151 maint show dwarf max-cache-age
1152 Renamed from "maint show dwarf2 max-cache-age".
1154 set debug dwarf-line
1155 show debug dwarf-line
1156 Control display of debugging info regarding DWARF line processing.
1159 show max-completions
1160 Set the maximum number of candidates to be considered during
1161 completion. The default value is 200. This limit allows GDB
1162 to avoid generating large completion lists, the computation of
1163 which can cause the debugger to become temporarily unresponsive.
1165 set history remove-duplicates
1166 show history remove-duplicates
1167 Control the removal of duplicate history entries.
1169 maint set symbol-cache-size
1170 maint show symbol-cache-size
1171 Control the size of the symbol cache.
1173 set|show record btrace bts buffer-size
1174 Set and show the size of the ring buffer used for branch tracing in
1176 The obtained size may differ from the requested size. Use "info
1177 record" to see the obtained buffer size.
1179 set debug linux-namespaces
1180 show debug linux-namespaces
1181 Control display of debugging info regarding Linux namespaces.
1183 set|show record btrace pt buffer-size
1184 Set and show the size of the ring buffer used for branch tracing in
1185 Intel Processor Trace format.
1186 The obtained size may differ from the requested size. Use "info
1187 record" to see the obtained buffer size.
1189 maint set|show btrace pt skip-pad
1190 Set and show whether PAD packets are skipped when computing the
1193 * The command 'thread apply all' can now support new option '-ascending'
1194 to call its specified command for all threads in ascending order.
1196 * Python/Guile scripting
1198 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1199 special section named `.debug_gdb_scripts'.
1201 * New remote packets
1203 qXfer:btrace-conf:read
1204 Return the branch trace configuration for the current thread.
1206 Qbtrace-conf:bts:size
1207 Set the requested ring buffer size for branch tracing in BTS format.
1210 Enable Intel Procesor Trace-based branch tracing for the current
1211 process. The remote stub reports support for this packet to GDB's
1214 Qbtrace-conf:pt:size
1215 Set the requested ring buffer size for branch tracing in Intel Processor
1219 Indicates a memory breakpoint instruction was executed, irrespective
1220 of whether it was GDB that planted the breakpoint or the breakpoint
1221 is hardcoded in the program. This is required for correct non-stop
1225 Indicates the target stopped for a hardware breakpoint. This is
1226 required for correct non-stop mode operation.
1229 Return information about files on the remote system.
1231 qXfer:exec-file:read
1232 Return the full absolute name of the file that was executed to
1233 create a process running on the remote system.
1236 Select the filesystem on which vFile: operations with filename
1237 arguments will operate. This is required for GDB to be able to
1238 access files on remote targets where the remote stub does not
1239 share a common filesystem with the inferior(s).
1242 Indicates that a fork system call was executed.
1245 Indicates that a vfork system call was executed.
1247 vforkdone stop reason
1248 Indicates that a vfork child of the specified process has executed
1249 an exec or exit, allowing the vfork parent to resume execution.
1251 fork-events and vfork-events features in qSupported
1252 The qSupported packet allows GDB to request support for fork and
1253 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1254 and the qSupported response can contain the corresponding
1255 'stubfeatures'. Set and show commands can be used to display
1256 whether these features are enabled.
1258 * Extended-remote fork events
1260 ** GDB now has support for fork events on extended-remote Linux
1261 targets. For targets with Linux kernels 2.5.60 and later, this
1262 enables follow-fork-mode and detach-on-fork for both fork and
1263 vfork, as well as fork and vfork catchpoints.
1265 * The info record command now shows the recording format and the
1266 branch tracing configuration for the current thread when using
1267 the btrace record target.
1268 For the BTS format, it shows the ring buffer size.
1270 * GDB now has support for DTrace USDT (Userland Static Defined
1271 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1273 * GDB now supports access to vector registers on S/390 GNU/Linux
1276 * Removed command line options
1278 -xdb HP-UX XDB compatibility mode.
1280 * Removed targets and native configurations
1282 HP/PA running HP-UX hppa*-*-hpux*
1283 Itanium running HP-UX ia64-*-hpux*
1285 * New configure options
1288 This configure option allows the user to build GDB with support for
1289 Intel Processor Trace (default: auto). This requires libipt.
1291 --with-libipt-prefix=PATH
1292 Specify the path to the version of libipt that GDB should use.
1293 $PATH/include should contain the intel-pt.h header and
1294 $PATH/lib should contain the libipt.so library.
1296 *** Changes in GDB 7.9.1
1300 ** Xmethods can now specify a result type.
1302 *** Changes in GDB 7.9
1304 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1308 ** You can now access frame registers from Python scripts.
1309 ** New attribute 'producer' for gdb.Symtab objects.
1310 ** gdb.Objfile objects have a new attribute "progspace",
1311 which is the gdb.Progspace object of the containing program space.
1312 ** gdb.Objfile objects have a new attribute "owner".
1313 ** gdb.Objfile objects have a new attribute "build_id",
1314 which is the build ID generated when the file was built.
1315 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1316 ** A new event "gdb.clear_objfiles" has been added, triggered when
1317 selecting a new file to debug.
1318 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1319 ** New function gdb.lookup_objfile.
1321 New events which are triggered when GDB modifies the state of the
1324 ** gdb.events.inferior_call_pre: Function call is about to be made.
1325 ** gdb.events.inferior_call_post: Function call has just been made.
1326 ** gdb.events.memory_changed: A memory location has been altered.
1327 ** gdb.events.register_changed: A register has been altered.
1329 * New Python-based convenience functions:
1331 ** $_caller_is(name [, number_of_frames])
1332 ** $_caller_matches(regexp [, number_of_frames])
1333 ** $_any_caller_is(name [, number_of_frames])
1334 ** $_any_caller_matches(regexp [, number_of_frames])
1336 * GDB now supports the compilation and injection of source code into
1337 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1338 to compile the source code to object code, and if successful, inject
1339 and execute that code within the current context of the inferior.
1340 Currently the C language is supported. The commands used to
1341 interface with this new feature are:
1343 compile code [-raw|-r] [--] [source code]
1344 compile file [-raw|-r] filename
1348 demangle [-l language] [--] name
1349 Demangle "name" in the specified language, or the current language
1350 if elided. This command is renamed from the "maint demangle" command.
1351 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1352 as "maint demangler-warning".
1354 queue-signal signal-name-or-number
1355 Queue a signal to be delivered to the thread when it is resumed.
1357 add-auto-load-scripts-directory directory
1358 Add entries to the list of directories from which to load auto-loaded
1361 maint print user-registers
1362 List all currently available "user" registers.
1364 compile code [-r|-raw] [--] [source code]
1365 Compile, inject, and execute in the inferior the executable object
1366 code produced by compiling the provided source code.
1368 compile file [-r|-raw] filename
1369 Compile and inject into the inferior the executable object code
1370 produced by compiling the source code stored in the filename
1373 * On resume, GDB now always passes the signal the program had stopped
1374 for to the thread the signal was sent to, even if the user changed
1375 threads before resuming. Previously GDB would often (but not
1376 always) deliver the signal to the thread that happens to be current
1379 * Conversely, the "signal" command now consistently delivers the
1380 requested signal to the current thread. GDB now asks for
1381 confirmation if the program had stopped for a signal and the user
1382 switched threads meanwhile.
1384 * "breakpoint always-inserted" modes "off" and "auto" merged.
1386 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1387 won't remove breakpoints from the target until all threads stop,
1388 even in non-stop mode. The "auto" mode has been removed, and "off"
1389 is now the default mode.
1393 set debug symbol-lookup
1394 show debug symbol-lookup
1395 Control display of debugging info regarding symbol lookup.
1399 ** The -list-thread-groups command outputs an exit-code field for
1400 inferiors that have exited.
1404 MIPS SDE mips*-sde*-elf*
1408 Support for these obsolete configurations has been removed.
1410 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1411 SGI Irix-5.x mips-*-irix5*
1412 SGI Irix-6.x mips-*-irix6*
1413 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1414 VAX running Ultrix vax-*-ultrix*
1416 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1417 and "assf"), have been removed. Use the "sharedlibrary" command, or
1418 its alias "share", instead.
1420 *** Changes in GDB 7.8
1422 * New command line options
1425 This is an alias for the --data-directory option.
1427 * GDB supports printing and modifying of variable length automatic arrays
1428 as specified in ISO C99.
1430 * The ARM simulator now supports instruction level tracing
1431 with or without disassembly.
1435 GDB now has support for scripting using Guile. Whether this is
1436 available is determined at configure time.
1437 Guile version 2.0 or greater is required.
1438 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1440 * New commands (for set/show, see "New options" below)
1444 Invoke CODE by passing it to the Guile interpreter.
1448 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1450 info auto-load guile-scripts [regexp]
1451 Print the list of automatically loaded Guile scripts.
1453 * The source command is now capable of sourcing Guile scripts.
1454 This feature is dependent on the debugger being built with Guile support.
1458 set print symbol-loading (off|brief|full)
1459 show print symbol-loading
1460 Control whether to print informational messages when loading symbol
1461 information for a file. The default is "full", but when debugging
1462 programs with large numbers of shared libraries the amount of output
1463 becomes less useful.
1465 set guile print-stack (none|message|full)
1466 show guile print-stack
1467 Show a stack trace when an error is encountered in a Guile script.
1469 set auto-load guile-scripts (on|off)
1470 show auto-load guile-scripts
1471 Control auto-loading of Guile script files.
1473 maint ada set ignore-descriptive-types (on|off)
1474 maint ada show ignore-descriptive-types
1475 Control whether the debugger should ignore descriptive types in Ada
1476 programs. The default is not to ignore the descriptive types. See
1477 the user manual for more details on descriptive types and the intended
1478 usage of this option.
1480 set auto-connect-native-target
1482 Control whether GDB is allowed to automatically connect to the
1483 native target for the run, attach, etc. commands when not connected
1484 to any target yet. See also "target native" below.
1486 set record btrace replay-memory-access (read-only|read-write)
1487 show record btrace replay-memory-access
1488 Control what memory accesses are allowed during replay.
1490 maint set target-async (on|off)
1491 maint show target-async
1492 This controls whether GDB targets operate in synchronous or
1493 asynchronous mode. Normally the default is asynchronous, if it is
1494 available; but this can be changed to more easily debug problems
1495 occurring only in synchronous mode.
1497 set mi-async (on|off)
1499 Control whether MI asynchronous mode is preferred. This supersedes
1500 "set target-async" of previous GDB versions.
1502 * "set target-async" is deprecated as a CLI option and is now an alias
1503 for "set mi-async" (only puts MI into async mode).
1505 * Background execution commands (e.g., "c&", "s&", etc.) are now
1506 possible ``out of the box'' if the target supports them. Previously
1507 the user would need to explicitly enable the possibility with the
1508 "set target-async on" command.
1510 * New features in the GDB remote stub, GDBserver
1512 ** New option --debug-format=option1[,option2,...] allows one to add
1513 additional text to each output. At present only timestamps
1514 are supported: --debug-format=timestamps.
1515 Timestamps can also be turned on with the
1516 "monitor set debug-format timestamps" command from GDB.
1518 * The 'record instruction-history' command now starts counting instructions
1519 at one. This also affects the instruction ranges reported by the
1520 'record function-call-history' command when given the /i modifier.
1522 * The command 'record function-call-history' supports a new modifier '/c' to
1523 indent the function names based on their call stack depth.
1524 The fields for the '/i' and '/l' modifier have been reordered.
1525 The source line range is now prefixed with 'at'.
1526 The instruction range is now prefixed with 'inst'.
1527 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1528 "record instruction-history" and "list" commands.
1530 * The ranges given as arguments to the 'record function-call-history' and
1531 'record instruction-history' commands are now inclusive.
1533 * The btrace record target now supports the 'record goto' command.
1534 For locations inside the execution trace, the back trace is computed
1535 based on the information stored in the execution trace.
1537 * The btrace record target supports limited reverse execution and replay.
1538 The target does not record data and therefore does not allow reading
1539 memory or registers.
1541 * The "catch syscall" command now works on s390*-linux* targets.
1543 * The "compare-sections" command is no longer specific to target
1544 remote. It now works with all targets.
1546 * All native targets are now consistently called "native".
1547 Consequently, the "target child", "target GNU", "target djgpp",
1548 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1549 commands have been replaced with "target native". The QNX/NTO port
1550 leaves the "procfs" target in place and adds a "native" target for
1551 consistency with other ports. The impact on users should be minimal
1552 as these commands previously either throwed an error, or were
1553 no-ops. The target's name is visible in the output of the following
1554 commands: "help target", "info target", "info files", "maint print
1557 * The "target native" command now connects to the native target. This
1558 can be used to launch native programs even when "set
1559 auto-connect-native-target" is set to off.
1561 * GDB now supports access to Intel MPX registers on GNU/Linux.
1563 * Support for Intel AVX-512 registers on GNU/Linux.
1564 Support displaying and modifying Intel AVX-512 registers
1565 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1567 * New remote packets
1569 qXfer:btrace:read's annex
1570 The qXfer:btrace:read packet supports a new annex 'delta' to read
1571 branch trace incrementally.
1575 ** Valid Python operations on gdb.Value objects representing
1576 structs/classes invoke the corresponding overloaded operators if
1578 ** New `Xmethods' feature in the Python API. Xmethods are
1579 additional methods or replacements for existing methods of a C++
1580 class. This feature is useful for those cases where a method
1581 defined in C++ source code could be inlined or optimized out by
1582 the compiler, making it unavailable to GDB.
1585 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1587 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1588 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1589 its alias "share", instead.
1591 * The commands "set remotebaud" and "show remotebaud" are no longer
1592 supported. Use "set serial baud" and "show serial baud" (respectively)
1597 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1598 target-async". The latter is left as a deprecated alias of the
1599 former for backward compatibility. If the target supports it,
1600 CLI background execution commands are now always possible by
1601 default, independently of whether the frontend stated a
1602 preference for asynchronous execution with "-gdb-set mi-async".
1603 Previously "-gdb-set target-async off" affected both MI execution
1604 commands and CLI execution commands.
1606 *** Changes in GDB 7.7
1608 * Improved support for process record-replay and reverse debugging on
1609 arm*-linux* targets. Support for thumb32 and syscall instruction
1610 recording has been added.
1612 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1614 * GDB now supports Fission DWP file format version 2.
1615 http://gcc.gnu.org/wiki/DebugFission
1617 * New convenience function "$_isvoid", to check whether an expression
1618 is void. A void expression is an expression where the type of the
1619 result is "void". For example, some convenience variables may be
1620 "void" when evaluated (e.g., "$_exitcode" before the execution of
1621 the program being debugged; or an undefined convenience variable).
1622 Another example, when calling a function whose return type is
1625 * The "maintenance print objfiles" command now takes an optional regexp.
1627 * The "catch syscall" command now works on arm*-linux* targets.
1629 * GDB now consistently shows "<not saved>" when printing values of
1630 registers the debug info indicates have not been saved in the frame
1631 and there's nowhere to retrieve them from
1632 (callee-saved/call-clobbered registers):
1637 (gdb) info registers rax
1640 Before, the former would print "<optimized out>", and the latter
1641 "*value not available*".
1643 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1648 ** Frame filters and frame decorators have been added.
1649 ** Temporary breakpoints are now supported.
1650 ** Line tables representation has been added.
1651 ** New attribute 'parent_type' for gdb.Field objects.
1652 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1653 ** New attribute 'name' for gdb.Type objects.
1657 Nios II ELF nios2*-*-elf
1658 Nios II GNU/Linux nios2*-*-linux
1659 Texas Instruments MSP430 msp430*-*-elf
1661 * Removed native configurations
1663 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1664 been removed. ELF variants of these configurations are kept supported.
1666 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1667 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1668 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1669 i[34567]86-*-openbsd3.[0-3]
1670 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1671 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1672 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1676 Like "catch throw", but catches a re-thrown exception.
1677 maint check-psymtabs
1678 Renamed from old "maint check-symtabs".
1680 Perform consistency checks on symtabs.
1681 maint expand-symtabs
1682 Expand symtabs matching an optional regexp.
1685 Display the details of GDB configure-time options.
1687 maint set|show per-command
1688 maint set|show per-command space
1689 maint set|show per-command time
1690 maint set|show per-command symtab
1691 Enable display of per-command gdb resource usage.
1693 remove-symbol-file FILENAME
1694 remove-symbol-file -a ADDRESS
1695 Remove a symbol file added via add-symbol-file. The file to remove
1696 can be identified by its filename or by an address that lies within
1697 the boundaries of this symbol file in memory.
1700 info exceptions REGEXP
1701 Display the list of Ada exceptions defined in the program being
1702 debugged. If provided, only the exceptions whose names match REGEXP
1707 set debug symfile off|on
1709 Control display of debugging info regarding reading symbol files and
1710 symbol tables within those files
1712 set print raw frame-arguments
1713 show print raw frame-arguments
1714 Set/show whether to print frame arguments in raw mode,
1715 disregarding any defined pretty-printers.
1717 set remote trace-status-packet
1718 show remote trace-status-packet
1719 Set/show the use of remote protocol qTStatus packet.
1723 Control display of debugging messages related to Nios II targets.
1727 Control whether target-assisted range stepping is enabled.
1729 set startup-with-shell
1730 show startup-with-shell
1731 Specifies whether Unix child processes are started via a shell or
1736 Use the target memory cache for accesses to the code segment. This
1737 improves performance of remote debugging (particularly disassembly).
1739 * You can now use a literal value 'unlimited' for options that
1740 interpret 0 or -1 as meaning "unlimited". E.g., "set
1741 trace-buffer-size unlimited" is now an alias for "set
1742 trace-buffer-size -1" and "set height unlimited" is now an alias for
1745 * The "set debug symtab-create" debugging option of GDB has been changed to
1746 accept a verbosity level. 0 means "off", 1 provides basic debugging
1747 output, and values of 2 or greater provides more verbose output.
1749 * New command-line options
1751 Display the details of GDB configure-time options.
1753 * The command 'tsave' can now support new option '-ctf' to save trace
1754 buffer in Common Trace Format.
1756 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1759 * GDB now implements the the C++ 'typeid' operator.
1761 * The new convenience variable $_exception holds the exception being
1762 thrown or caught at an exception-related catchpoint.
1764 * The exception-related catchpoints, like "catch throw", now accept a
1765 regular expression which can be used to filter exceptions by type.
1767 * The new convenience variable $_exitsignal is automatically set to
1768 the terminating signal number when the program being debugged dies
1769 due to an uncaught signal.
1773 ** All MI commands now accept an optional "--language" option.
1774 Support for this feature can be verified by using the "-list-features"
1775 command, which should contain "language-option".
1777 ** The new command -info-gdb-mi-command allows the user to determine
1778 whether a GDB/MI command is supported or not.
1780 ** The "^error" result record returned when trying to execute an undefined
1781 GDB/MI command now provides a variable named "code" whose content is the
1782 "undefined-command" error code. Support for this feature can be verified
1783 by using the "-list-features" command, which should contain
1784 "undefined-command-error-code".
1786 ** The -trace-save MI command can optionally save trace buffer in Common
1789 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1791 ** The command -data-list-register-values now accepts an optional
1792 "--skip-unavailable" option. When used, only the available registers
1795 ** The new command -trace-frame-collected dumps collected variables,
1796 computed expressions, tvars, memory and registers in a traceframe.
1798 ** The commands -stack-list-locals, -stack-list-arguments and
1799 -stack-list-variables now accept an option "--skip-unavailable".
1800 When used, only the available locals or arguments are displayed.
1802 ** The -exec-run command now accepts an optional "--start" option.
1803 When used, the command follows the same semantics as the "start"
1804 command, stopping the program's execution at the start of its
1805 main subprogram. Support for this feature can be verified using
1806 the "-list-features" command, which should contain
1807 "exec-run-start-option".
1809 ** The new commands -catch-assert and -catch-exceptions insert
1810 catchpoints stopping the program when Ada exceptions are raised.
1812 ** The new command -info-ada-exceptions provides the equivalent of
1813 the new "info exceptions" command.
1815 * New system-wide configuration scripts
1816 A GDB installation now provides scripts suitable for use as system-wide
1817 configuration scripts for the following systems:
1821 * GDB now supports target-assigned range stepping with remote targets.
1822 This improves the performance of stepping source lines by reducing
1823 the number of control packets from/to GDB. See "New remote packets"
1826 * GDB now understands the element 'tvar' in the XML traceframe info.
1827 It has the id of the collected trace state variables.
1829 * On S/390 targets that provide the transactional-execution feature,
1830 the program interruption transaction diagnostic block (TDB) is now
1831 represented as a number of additional "registers" in GDB.
1833 * New remote packets
1837 The vCont packet supports a new 'r' action, that tells the remote
1838 stub to step through an address range itself, without GDB
1839 involvemement at each single-step.
1841 qXfer:libraries-svr4:read's annex
1842 The previously unused annex of the qXfer:libraries-svr4:read packet
1843 is now used to support passing an argument list. The remote stub
1844 reports support for this argument list to GDB's qSupported query.
1845 The defined arguments are "start" and "prev", used to reduce work
1846 necessary for library list updating, resulting in significant
1849 * New features in the GDB remote stub, GDBserver
1851 ** GDBserver now supports target-assisted range stepping. Currently
1852 enabled on x86/x86_64 GNU/Linux targets.
1854 ** GDBserver now adds element 'tvar' in the XML in the reply to
1855 'qXfer:traceframe-info:read'. It has the id of the collected
1856 trace state variables.
1858 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1861 * New 'z' formatter for printing and examining memory, this displays the
1862 value as hexadecimal zero padded on the left to the size of the type.
1864 * GDB can now use Windows x64 unwinding data.
1866 * The "set remotebaud" command has been replaced by "set serial baud".
1867 Similarly, "show remotebaud" has been replaced by "show serial baud".
1868 The "set remotebaud" and "show remotebaud" commands are still available
1869 to provide backward compatibility with older versions of GDB.
1871 *** Changes in GDB 7.6
1873 * Target record has been renamed to record-full.
1874 Record/replay is now enabled with the "record full" command.
1875 This also affects settings that are associated with full record/replay
1876 that have been moved from "set/show record" to "set/show record full":
1878 set|show record full insn-number-max
1879 set|show record full stop-at-limit
1880 set|show record full memory-query
1882 * A new record target "record-btrace" has been added. The new target
1883 uses hardware support to record the control-flow of a process. It
1884 does not support replaying the execution, but it implements the
1885 below new commands for investigating the recorded execution log.
1886 This new recording method can be enabled using:
1890 The "record-btrace" target is only available on Intel Atom processors
1891 and requires a Linux kernel 2.6.32 or later.
1893 * Two new commands have been added for record/replay to give information
1894 about the recorded execution without having to replay the execution.
1895 The commands are only supported by "record btrace".
1897 record instruction-history prints the execution history at
1898 instruction granularity
1900 record function-call-history prints the execution history at
1901 function granularity
1903 * New native configurations
1905 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1906 FreeBSD/powerpc powerpc*-*-freebsd
1907 x86_64/Cygwin x86_64-*-cygwin*
1908 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1912 ARM AArch64 aarch64*-*-elf
1913 ARM AArch64 GNU/Linux aarch64*-*-linux
1914 Lynx 178 PowerPC powerpc-*-lynx*178
1915 x86_64/Cygwin x86_64-*-cygwin*
1916 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1918 * If the configured location of system.gdbinit file (as given by the
1919 --with-system-gdbinit option at configure time) is in the
1920 data-directory (as specified by --with-gdb-datadir at configure
1921 time) or in one of its subdirectories, then GDB will look for the
1922 system-wide init file in the directory specified by the
1923 --data-directory command-line option.
1925 * New command line options:
1927 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1928 other initialization files, unlike -nx which disables all of them.
1930 * Removed command line options
1932 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1935 * The 'ptype' and 'whatis' commands now accept an argument to control
1938 * 'info proc' now works on some core files.
1942 ** Vectors can be created with gdb.Type.vector.
1944 ** Python's atexit.register now works in GDB.
1946 ** Types can be pretty-printed via a Python API.
1948 ** Python 3 is now supported (in addition to Python 2.4 or later)
1950 ** New class gdb.Architecture exposes GDB's internal representation
1951 of architecture in the Python API.
1953 ** New method Frame.architecture returns the gdb.Architecture object
1954 corresponding to the frame's architecture.
1956 * New Python-based convenience functions:
1958 ** $_memeq(buf1, buf2, length)
1959 ** $_streq(str1, str2)
1961 ** $_regex(str, regex)
1963 * The 'cd' command now defaults to using '~' (the home directory) if not
1966 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1967 default for GCC since November 2000.
1969 * The command 'forward-search' can now be abbreviated as 'fo'.
1971 * The command 'info tracepoints' can now display 'installed on target'
1972 or 'not installed on target' for each non-pending location of tracepoint.
1974 * New configure options
1976 --enable-libmcheck/--disable-libmcheck
1977 By default, development versions are built with -lmcheck on hosts
1978 that support it, in order to help track memory corruption issues.
1979 Release versions, on the other hand, are built without -lmcheck
1980 by default. The --enable-libmcheck/--disable-libmcheck configure
1981 options allow the user to override that default.
1982 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1983 This configure option allows the user to build GDB with
1984 libbabeltrace using which GDB can read Common Trace Format data.
1986 * New commands (for set/show, see "New options" below)
1989 Catch signals. This is similar to "handle", but allows commands and
1990 conditions to be attached.
1993 List the BFDs known to GDB.
1995 python-interactive [command]
1997 Start a Python interactive prompt, or evaluate the optional command
1998 and print the result of expressions.
2001 "py" is a new alias for "python".
2003 enable type-printer [name]...
2004 disable type-printer [name]...
2005 Enable or disable type printers.
2009 ** For the Renesas Super-H architecture, the "regs" command has been removed
2010 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2015 set print type methods (on|off)
2016 show print type methods
2017 Control whether method declarations are displayed by "ptype".
2018 The default is to show them.
2020 set print type typedefs (on|off)
2021 show print type typedefs
2022 Control whether typedef definitions are displayed by "ptype".
2023 The default is to show them.
2025 set filename-display basename|relative|absolute
2026 show filename-display
2027 Control the way in which filenames is displayed.
2028 The default is "relative", which preserves previous behavior.
2030 set trace-buffer-size
2031 show trace-buffer-size
2032 Request target to change the size of trace buffer.
2034 set remote trace-buffer-size-packet auto|on|off
2035 show remote trace-buffer-size-packet
2036 Control the use of the remote protocol `QTBuffer:size' packet.
2040 Control display of debugging messages related to ARM AArch64.
2043 set debug coff-pe-read
2044 show debug coff-pe-read
2045 Control display of debugging messages related to reading of COFF/PE
2050 Control display of debugging messages related to Mach-O symbols
2053 set debug notification
2054 show debug notification
2055 Control display of debugging info for async remote notification.
2059 ** Command parameter changes are now notified using new async record
2060 "=cmd-param-changed".
2061 ** Trace frame changes caused by command "tfind" are now notified using
2062 new async record "=traceframe-changed".
2063 ** The creation, deletion and modification of trace state variables
2064 are now notified using new async records "=tsv-created",
2065 "=tsv-deleted" and "=tsv-modified".
2066 ** The start and stop of process record are now notified using new
2067 async record "=record-started" and "=record-stopped".
2068 ** Memory changes are now notified using new async record
2070 ** The data-disassemble command response will include a "fullname" field
2071 containing the absolute file name when source has been requested.
2072 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2073 command, to allow pattern filling of memory areas.
2074 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2075 library load/unload events.
2076 ** The response to breakpoint commands and breakpoint async records
2077 includes an "installed" field containing a boolean state about each
2078 non-pending tracepoint location is whether installed on target or not.
2079 ** Output of the "-trace-status" command includes a "trace-file" field
2080 containing the name of the trace file being examined. This field is
2081 optional, and only present when examining a trace file.
2082 ** The "fullname" field is now always present along with the "file" field,
2083 even if the file cannot be found by GDB.
2085 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2086 You must have the LZMA library available when configuring GDB for this
2087 feature to be enabled. For more information, see:
2088 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2090 * New remote packets
2093 Set the size of trace buffer. The remote stub reports support for this
2094 packet to gdb's qSupported query.
2097 Enable Branch Trace Store (BTS)-based branch tracing for the current
2098 thread. The remote stub reports support for this packet to gdb's
2102 Disable branch tracing for the current thread. The remote stub reports
2103 support for this packet to gdb's qSupported query.
2106 Read the traced branches for the current thread. The remote stub
2107 reports support for this packet to gdb's qSupported query.
2109 *** Changes in GDB 7.5
2111 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2112 for more x32 ABI info.
2114 * GDB now supports access to MIPS DSP registers on Linux targets.
2116 * GDB now supports debugging microMIPS binaries.
2118 * The "info os" command on GNU/Linux can now display information on
2119 several new classes of objects managed by the operating system:
2120 "info os procgroups" lists process groups
2121 "info os files" lists file descriptors
2122 "info os sockets" lists internet-domain sockets
2123 "info os shm" lists shared-memory regions
2124 "info os semaphores" lists semaphores
2125 "info os msg" lists message queues
2126 "info os modules" lists loaded kernel modules
2128 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2129 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2130 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2131 options and inspect the probe arguments using the new $_probe_arg family
2132 of convenience variables. You can obtain more information about SystemTap
2133 in <http://sourceware.org/systemtap/>.
2135 * GDB now supports reversible debugging on ARM, it allows you to
2136 debug basic ARM and THUMB instructions, and provides
2137 record/replay support.
2139 * The option "symbol-reloading" has been deleted as it is no longer used.
2143 ** GDB commands implemented in Python can now be put in command class
2146 ** The "maint set python print-stack on|off" is now deleted.
2148 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2149 apply "flag enum"-style pretty-printing to any enum.
2151 ** gdb.lookup_symbol can now work when there is no current frame.
2153 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2154 the source at which the symbol was defined.
2156 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2157 method 'value'. The former indicates whether the symbol needs a
2158 frame in order to compute its value, and the latter computes the
2161 ** A new method 'referenced_value' on gdb.Value objects which can
2162 dereference pointer as well as C++ reference values.
2164 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2165 which return the global and static blocks (as gdb.Block objects),
2166 of the underlying symbol table, respectively.
2168 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2169 object associated with a PC value.
2171 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2172 of the address range occupied by code for the current source line.
2174 * Go language support.
2175 GDB now supports debugging programs written in the Go programming
2178 * GDBserver now supports stdio connections.
2179 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2181 * The binary "gdbtui" can no longer be built or installed.
2182 Use "gdb -tui" instead.
2184 * GDB will now print "flag" enums specially. A flag enum is one where
2185 all the enumerator values have no bits in common when pairwise
2186 "and"ed. When printing a value whose type is a flag enum, GDB will
2187 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2188 (gdb) print (enum E) 3
2191 * The filename part of a linespec will now match trailing components
2192 of a source file name. For example, "break gcc/expr.c:1000" will
2193 now set a breakpoint in build/gcc/expr.c, but not
2194 build/libcpp/expr.c.
2196 * The "info proc" and "generate-core-file" commands will now also
2197 work on remote targets connected to GDBserver on Linux.
2199 * The command "info catch" has been removed. It has been disabled
2200 since December 2007.
2202 * The "catch exception" and "catch assert" commands now accept
2203 a condition at the end of the command, much like the "break"
2204 command does. For instance:
2206 (gdb) catch exception Constraint_Error if Barrier = True
2208 Previously, it was possible to add a condition to such catchpoints,
2209 but it had to be done as a second step, after the catchpoint had been
2210 created, using the "condition" command.
2212 * The "info static-tracepoint-marker" command will now also work on
2213 native Linux targets with in-process agent.
2215 * GDB can now set breakpoints on inlined functions.
2217 * The .gdb_index section has been updated to include symbols for
2218 inlined functions. GDB will ignore older .gdb_index sections by
2219 default, which could cause symbol files to be loaded more slowly
2220 until their .gdb_index sections can be recreated. The new command
2221 "set use-deprecated-index-sections on" will cause GDB to use any older
2222 .gdb_index sections it finds. This will restore performance, but the
2223 ability to set breakpoints on inlined functions will be lost in symbol
2224 files with older .gdb_index sections.
2226 The .gdb_index section has also been updated to record more information
2227 about each symbol. This speeds up the "info variables", "info functions"
2228 and "info types" commands when used with programs having the .gdb_index
2229 section, as well as speeding up debugging with shared libraries using
2230 the .gdb_index section.
2232 * Ada support for GDB/MI Variable Objects has been added.
2234 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2239 ** New command -info-os is the MI equivalent of "info os".
2241 ** Output logs ("set logging" and related) now include MI output.
2245 ** "set use-deprecated-index-sections on|off"
2246 "show use-deprecated-index-sections on|off"
2247 Controls the use of deprecated .gdb_index sections.
2249 ** "catch load" and "catch unload" can be used to stop when a shared
2250 library is loaded or unloaded, respectively.
2252 ** "enable count" can be used to auto-disable a breakpoint after
2255 ** "info vtbl" can be used to show the virtual method tables for
2256 C++ and Java objects.
2258 ** "explore" and its sub commands "explore value" and "explore type"
2259 can be used to recursively explore values and types of
2260 expressions. These commands are available only if GDB is
2261 configured with '--with-python'.
2263 ** "info auto-load" shows status of all kinds of auto-loaded files,
2264 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2265 sequences of commands files, "info auto-load python-scripts"
2266 shows status of auto-loading Python script files,
2267 "info auto-load local-gdbinit" shows status of loading init file
2268 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2269 status of inferior specific thread debugging shared library loading.
2271 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2272 and "show auto-load-scripts" commands have been deprecated, use their
2273 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2274 and "show auto-load python-scripts" counterparts instead.
2276 ** "dprintf location,format,args..." creates a dynamic printf, which
2277 is basically a breakpoint that does a printf and immediately
2278 resumes your program's execution, so it is like a printf that you
2279 can insert dynamically at runtime instead of at compiletime.
2281 ** "set print symbol"
2283 Controls whether GDB attempts to display the symbol, if any,
2284 corresponding to addresses it prints. This defaults to "on", but
2285 you can set it to "off" to restore GDB's previous behavior.
2287 * Deprecated commands
2289 ** For the Renesas Super-H architecture, the "regs" command has been
2290 deprecated, and "info all-registers" should be used instead.
2294 Renesas RL78 rl78-*-elf
2295 HP OpenVMS ia64 ia64-hp-openvms*
2297 * GDBserver supports evaluation of breakpoint conditions. When
2298 support is advertised by GDBserver, GDB may be told to send the
2299 breakpoint conditions in bytecode form to GDBserver. GDBserver
2300 will only report the breakpoint trigger to GDB when its condition
2305 set mips compression
2306 show mips compression
2307 Select the compressed ISA encoding used in functions that have no symbol
2308 information available. The encoding can be set to either of:
2311 and is updated automatically from ELF file flags if available.
2313 set breakpoint condition-evaluation
2314 show breakpoint condition-evaluation
2315 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2316 GDBserver ("target"). Default option "auto" chooses the most efficient
2318 This option can improve debugger efficiency depending on the speed of the
2322 Disable auto-loading globally.
2325 Show auto-loading setting of all kinds of auto-loaded files.
2327 set auto-load gdb-scripts on|off
2328 show auto-load gdb-scripts
2329 Control auto-loading of GDB canned sequences of commands files.
2331 set auto-load python-scripts on|off
2332 show auto-load python-scripts
2333 Control auto-loading of Python script files.
2335 set auto-load local-gdbinit on|off
2336 show auto-load local-gdbinit
2337 Control loading of init file (.gdbinit) from current directory.
2339 set auto-load libthread-db on|off
2340 show auto-load libthread-db
2341 Control auto-loading of inferior specific thread debugging shared library.
2343 set auto-load scripts-directory <dir1>[:<dir2>...]
2344 show auto-load scripts-directory
2345 Set a list of directories from which to load auto-loaded scripts.
2346 Automatically loaded Python scripts and GDB scripts are located in one
2347 of the directories listed by this option.
2348 The delimiter (':' above) may differ according to the host platform.
2350 set auto-load safe-path <dir1>[:<dir2>...]
2351 show auto-load safe-path
2352 Set a list of directories from which it is safe to auto-load files.
2353 The delimiter (':' above) may differ according to the host platform.
2355 set debug auto-load on|off
2356 show debug auto-load
2357 Control display of debugging info for auto-loading the files above.
2359 set dprintf-style gdb|call|agent
2361 Control the way in which a dynamic printf is performed; "gdb"
2362 requests a GDB printf command, while "call" causes dprintf to call a
2363 function in the inferior. "agent" requests that the target agent
2364 (such as GDBserver) do the printing.
2366 set dprintf-function <expr>
2367 show dprintf-function
2368 set dprintf-channel <expr>
2369 show dprintf-channel
2370 Set the function and optional first argument to the call when using
2371 the "call" style of dynamic printf.
2373 set disconnected-dprintf on|off
2374 show disconnected-dprintf
2375 Control whether agent-style dynamic printfs continue to be in effect
2376 after GDB disconnects.
2378 * New configure options
2380 --with-auto-load-dir
2381 Configure default value for the 'set auto-load scripts-directory'
2382 setting above. It defaults to '$debugdir:$datadir/auto-load',
2383 $debugdir representing global debugging info directories (available
2384 via 'show debug-file-directory') and $datadir representing GDB's data
2385 directory (available via 'show data-directory').
2387 --with-auto-load-safe-path
2388 Configure default value for the 'set auto-load safe-path' setting
2389 above. It defaults to the --with-auto-load-dir setting.
2391 --without-auto-load-safe-path
2392 Set 'set auto-load safe-path' to '/', effectively disabling this
2395 * New remote packets
2397 z0/z1 conditional breakpoints extension
2399 The z0/z1 breakpoint insertion packets have been extended to carry
2400 a list of conditional expressions over to the remote stub depending on the
2401 condition evaluation mode. The use of this extension can be controlled
2402 via the "set remote conditional-breakpoints-packet" command.
2406 Specify the signals which the remote stub may pass to the debugged
2407 program without GDB involvement.
2409 * New command line options
2411 --init-command=FILE, -ix Like --command, -x but execute it
2412 before loading inferior.
2413 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2414 execute it before loading inferior.
2416 *** Changes in GDB 7.4
2418 * GDB now handles ambiguous linespecs more consistently; the existing
2419 FILE:LINE support has been expanded to other types of linespecs. A
2420 breakpoint will now be set on all matching locations in all
2421 inferiors, and locations will be added or removed according to
2424 * GDB now allows you to skip uninteresting functions and files when
2425 stepping with the "skip function" and "skip file" commands.
2427 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2428 and "show remote hardware-watchpoint-length-limit". These allows to
2429 set or show the maximum length limit (in bytes) of a remote
2430 target hardware watchpoint.
2432 This allows e.g. to use "unlimited" hardware watchpoints with the
2433 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2434 watchpoints are slower than real hardware watchpoints but are
2435 significantly faster than gdb software watchpoints.
2439 ** The register_pretty_printer function in module gdb.printing now takes
2440 an optional `replace' argument. If True, the new printer replaces any
2443 ** The "maint set python print-stack on|off" command has been
2444 deprecated and will be deleted in GDB 7.5.
2445 A new command: "set python print-stack none|full|message" has
2446 replaced it. Additionally, the default for "print-stack" is
2447 now "message", which just prints the error message without
2450 ** A prompt substitution hook (prompt_hook) is now available to the
2453 ** A new Python module, gdb.prompt has been added to the GDB Python
2454 modules library. This module provides functionality for
2455 escape sequences in prompts (used by set/show
2456 extended-prompt). These escape sequences are replaced by their
2457 corresponding value.
2459 ** Python commands and convenience-functions located in
2460 'data-directory'/python/gdb/command and
2461 'data-directory'/python/gdb/function are now automatically loaded
2464 ** Blocks now provide four new attributes. global_block and
2465 static_block will return the global and static blocks
2466 respectively. is_static and is_global are boolean attributes
2467 that indicate if the block is one of those two types.
2469 ** Symbols now provide the "type" attribute, the type of the symbol.
2471 ** The "gdb.breakpoint" function has been deprecated in favor of
2474 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2475 of a function. This class is based on the "finish" command
2476 available in the CLI.
2478 ** Type objects for struct and union types now allow access to
2479 the fields using standard Python dictionary (mapping) methods.
2480 For example, "some_type['myfield']" now works, as does
2481 "some_type.items()".
2483 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2486 ** A new function, "deep_items" has been added to the gdb.types
2487 module in the GDB Python modules library. This function returns
2488 an iterator over the fields of a struct or union type. Unlike
2489 the standard Python "iteritems" method, it will recursively traverse
2490 any anonymous fields.
2494 ** "*stopped" events can report several new "reason"s, such as
2497 ** Breakpoint changes are now notified using new async records, like
2498 "=breakpoint-modified".
2500 ** New command -ada-task-info.
2502 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2503 $sdir specifies the default system locations of shared libraries.
2504 $pdir specifies the directory where the libpthread used by the application
2507 GDB no longer looks in $sdir and $pdir after it has searched the directories
2508 mentioned in libthread-db-search-path. If you want to search those
2509 directories, they must be specified in libthread-db-search-path.
2510 The default value of libthread-db-search-path on GNU/Linux and Solaris
2511 systems is now "$sdir:$pdir".
2513 $pdir is not supported by gdbserver, it is currently ignored.
2514 $sdir is supported by gdbserver.
2516 * New configure option --with-iconv-bin.
2517 When using the internationalization support like the one in the GNU C
2518 library, GDB will invoke the "iconv" program to get a list of supported
2519 character sets. If this program lives in a non-standard location, one can
2520 use this option to specify where to find it.
2522 * When natively debugging programs on PowerPC BookE processors running
2523 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2524 watchpoints, which specify a mask in addition to an address to watch.
2525 The mask specifies that some bits of an address (the bits which are
2526 reset in the mask) should be ignored when matching the address accessed
2527 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2528 section in the user manual for more details.
2530 * The new option --once causes GDBserver to stop listening for connections once
2531 the first connection is made. The listening port used by GDBserver will
2532 become available after that.
2534 * New commands "info macros" and "alias" have been added.
2536 * New function parameters suffix @entry specifies value of function parameter
2537 at the time the function got called. Entry values are available only since
2543 "!" is now an alias of the "shell" command.
2544 Note that no space is needed between "!" and SHELL COMMAND.
2548 watch EXPRESSION mask MASK_VALUE
2549 The watch command now supports the mask argument which allows creation
2550 of masked watchpoints, if the current architecture supports this feature.
2552 info auto-load-scripts [REGEXP]
2553 This command was formerly named "maintenance print section-scripts".
2554 It is now generally useful and is no longer a maintenance-only command.
2556 info macro [-all] [--] MACRO
2557 The info macro command has new options `-all' and `--'. The first for
2558 printing all definitions of a macro. The second for explicitly specifying
2559 the end of arguments and the beginning of the macro name in case the macro
2560 name starts with a hyphen.
2562 collect[/s] EXPRESSIONS
2563 The tracepoint collect command now takes an optional modifier "/s"
2564 that directs it to dereference pointer-to-character types and
2565 collect the bytes of memory up to a zero byte. The behavior is
2566 similar to what you see when you use the regular print command on a
2567 string. An optional integer following the "/s" sets a bound on the
2568 number of bytes that will be collected.
2571 The trace start command now interprets any supplied arguments as a
2572 note to be recorded with the trace run, with an effect similar to
2573 setting the variable trace-notes.
2576 The trace stop command now interprets any arguments as a note to be
2577 mentioned along with the tstatus report that the trace was stopped
2578 with a command. The effect is similar to setting the variable
2581 * Tracepoints can now be enabled and disabled at any time after a trace
2582 experiment has been started using the standard "enable" and "disable"
2583 commands. It is now possible to start a trace experiment with no enabled
2584 tracepoints; GDB will display a warning, but will allow the experiment to
2585 begin, assuming that tracepoints will be enabled as needed while the trace
2588 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2589 locations with 4-byte instructions, when they were previously
2590 limited to locations with instructions of 5 bytes or longer.
2594 set debug dwarf2-read
2595 show debug dwarf2-read
2596 Turns on or off display of debugging messages related to reading
2597 DWARF debug info. The default is off.
2599 set debug symtab-create
2600 show debug symtab-create
2601 Turns on or off display of debugging messages related to symbol table
2602 creation. The default is off.
2605 show extended-prompt
2606 Set the GDB prompt, and allow escape sequences to be inserted to
2607 display miscellaneous information (see 'help set extended-prompt'
2608 for the list of sequences). This prompt (and any information
2609 accessed through the escape sequences) is updated every time the
2610 prompt is displayed.
2612 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2613 show print entry-values
2614 Set printing of frame argument values at function entry. In some cases
2615 GDB can determine the value of function argument which was passed by the
2616 function caller, even if the value was modified inside the called function.
2618 set debug entry-values
2619 show debug entry-values
2620 Control display of debugging info for determining frame argument values at
2621 function entry and virtual tail call frames.
2623 set basenames-may-differ
2624 show basenames-may-differ
2625 Set whether a source file may have multiple base names.
2626 (A "base name" is the name of a file with the directory part removed.
2627 Example: The base name of "/home/user/hello.c" is "hello.c".)
2628 If set, GDB will canonicalize file names (e.g., expand symlinks)
2629 before comparing them. Canonicalization is an expensive operation,
2630 but it allows the same file be known by more than one base name.
2631 If not set (the default), all source files are assumed to have just
2632 one base name, and gdb will do file name comparisons more efficiently.
2638 Set a user name and notes for the current and any future trace runs.
2639 This is useful for long-running and/or disconnected traces, to
2640 inform others (or yourself) as to who is running the trace, supply
2641 contact information, or otherwise explain what is going on.
2643 set trace-stop-notes
2644 show trace-stop-notes
2645 Set a note attached to the trace run, that is displayed when the
2646 trace has been stopped by a tstop command. This is useful for
2647 instance as an explanation, if you are stopping a trace run that was
2648 started by someone else.
2650 * New remote packets
2654 Dynamically enable a tracepoint in a started trace experiment.
2658 Dynamically disable a tracepoint in a started trace experiment.
2662 Set the user and notes of the trace run.
2666 Query the current status of a tracepoint.
2670 Query the minimum length of instruction at which a fast tracepoint may
2673 * Dcache size (number of lines) and line-size are now runtime-configurable
2674 via "set dcache line" and "set dcache line-size" commands.
2678 Texas Instruments TMS320C6x tic6x-*-*
2682 Renesas RL78 rl78-*-elf
2684 *** Changes in GDB 7.3.1
2686 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2688 *** Changes in GDB 7.3
2690 * GDB has a new command: "thread find [REGEXP]".
2691 It finds the thread id whose name, target id, or thread extra info
2692 matches the given regular expression.
2694 * The "catch syscall" command now works on mips*-linux* targets.
2696 * The -data-disassemble MI command now supports modes 2 and 3 for
2697 dumping the instruction opcodes.
2699 * New command line options
2701 -data-directory DIR Specify DIR as the "data-directory".
2702 This is mostly for testing purposes.
2704 * The "maint set python auto-load on|off" command has been renamed to
2705 "set auto-load-scripts on|off".
2707 * GDB has a new command: "set directories".
2708 It is like the "dir" command except that it replaces the
2709 source path list instead of augmenting it.
2711 * GDB now understands thread names.
2713 On GNU/Linux, "info threads" will display the thread name as set by
2714 prctl or pthread_setname_np.
2716 There is also a new command, "thread name", which can be used to
2717 assign a name internally for GDB to display.
2720 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2721 has been integrated into GDB.
2725 ** The function gdb.Write now accepts an optional keyword 'stream'.
2726 This keyword, when provided, will direct the output to either
2727 stdout, stderr, or GDB's logging output.
2729 ** Parameters can now be be sub-classed in Python, and in particular
2730 you may implement the get_set_doc and get_show_doc functions.
2731 This improves how Parameter set/show documentation is processed
2732 and allows for more dynamic content.
2734 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2735 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2736 have an is_valid method.
2738 ** Breakpoints can now be sub-classed in Python, and in particular
2739 you may implement a 'stop' function that is executed each time
2740 the inferior reaches that breakpoint.
2742 ** New function gdb.lookup_global_symbol looks up a global symbol.
2744 ** GDB values in Python are now callable if the value represents a
2745 function. For example, if 'some_value' represents a function that
2746 takes two integer parameters and returns a value, you can call
2747 that function like so:
2749 result = some_value (10,20)
2751 ** Module gdb.types has been added.
2752 It contains a collection of utilities for working with gdb.Types objects:
2753 get_basic_type, has_field, make_enum_dict.
2755 ** Module gdb.printing has been added.
2756 It contains utilities for writing and registering pretty-printers.
2757 New classes: PrettyPrinter, SubPrettyPrinter,
2758 RegexpCollectionPrettyPrinter.
2759 New function: register_pretty_printer.
2761 ** New commands "info pretty-printers", "enable pretty-printer" and
2762 "disable pretty-printer" have been added.
2764 ** gdb.parameter("directories") is now available.
2766 ** New function gdb.newest_frame returns the newest frame in the
2769 ** The gdb.InferiorThread class has a new "name" attribute. This
2770 holds the thread's name.
2772 ** Python Support for Inferior events.
2773 Python scripts can add observers to be notified of events
2774 occurring in the process being debugged.
2775 The following events are currently supported:
2776 - gdb.events.cont Continue event.
2777 - gdb.events.exited Inferior exited event.
2778 - gdb.events.stop Signal received, and Breakpoint hit events.
2782 ** GDB now puts template parameters in scope when debugging in an
2783 instantiation. For example, if you have:
2785 template<int X> int func (void) { return X; }
2787 then if you step into func<5>, "print X" will show "5". This
2788 feature requires proper debuginfo support from the compiler; it
2789 was added to GCC 4.5.
2791 ** The motion commands "next", "finish", "until", and "advance" now
2792 work better when exceptions are thrown. In particular, GDB will
2793 no longer lose control of the inferior; instead, the GDB will
2794 stop the inferior at the point at which the exception is caught.
2795 This functionality requires a change in the exception handling
2796 code that was introduced in GCC 4.5.
2798 * GDB now follows GCC's rules on accessing volatile objects when
2799 reading or writing target state during expression evaluation.
2800 One notable difference to prior behavior is that "print x = 0"
2801 no longer generates a read of x; the value of the assignment is
2802 now always taken directly from the value being assigned.
2804 * GDB now has some support for using labels in the program's source in
2805 linespecs. For instance, you can use "advance label" to continue
2806 execution to a label.
2808 * GDB now has support for reading and writing a new .gdb_index
2809 section. This section holds a fast index of DWARF debugging
2810 information and can be used to greatly speed up GDB startup and
2811 operation. See the documentation for `save gdb-index' for details.
2813 * The "watch" command now accepts an optional "-location" argument.
2814 When used, this causes GDB to watch the memory referred to by the
2815 expression. Such a watchpoint is never deleted due to it going out
2818 * GDB now supports thread debugging of core dumps on GNU/Linux.
2820 GDB now activates thread debugging using the libthread_db library
2821 when debugging GNU/Linux core dumps, similarly to when debugging
2822 live processes. As a result, when debugging a core dump file, GDB
2823 is now able to display pthread_t ids of threads. For example, "info
2824 threads" shows the same output as when debugging the process when it
2825 was live. In earlier releases, you'd see something like this:
2828 * 1 LWP 6780 main () at main.c:10
2830 While now you see this:
2833 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2835 It is also now possible to inspect TLS variables when debugging core
2838 When debugging a core dump generated on a machine other than the one
2839 used to run GDB, you may need to point GDB at the correct
2840 libthread_db library with the "set libthread-db-search-path"
2841 command. See the user manual for more details on this command.
2843 * When natively debugging programs on PowerPC BookE processors running
2844 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2845 which stop execution of the inferior whenever it executes an instruction
2846 at any address within the specified range. See the "PowerPC Embedded"
2847 section in the user manual for more details.
2849 * New features in the GDB remote stub, GDBserver
2851 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2852 and i686 LynxOS (version 5.x).
2854 ** GDBserver is now supported on Blackfin Linux.
2856 * New native configurations
2858 ia64 HP-UX ia64-*-hpux*
2862 Analog Devices, Inc. Blackfin Processor bfin-*
2864 * Ada task switching is now supported on sparc-elf targets when
2865 debugging a program using the Ravenscar Profile. For more information,
2866 see the "Tasking Support when using the Ravenscar Profile" section
2867 in the GDB user manual.
2869 * Guile support was removed.
2871 * New features in the GNU simulator
2873 ** The --map-info flag lists all known core mappings.
2875 ** CFI flashes may be simulated via the "cfi" device.
2877 *** Changes in GDB 7.2
2879 * Shared library support for remote targets by default
2881 When GDB is configured for a generic, non-OS specific target, like
2882 for example, --target=arm-eabi or one of the many *-*-elf targets,
2883 GDB now queries remote stubs for loaded shared libraries using the
2884 `qXfer:libraries:read' packet. Previously, shared library support
2885 was always disabled for such configurations.
2889 ** Argument Dependent Lookup (ADL)
2891 In C++ ADL lookup directs function search to the namespaces of its
2892 arguments even if the namespace has not been imported.
2902 Here the compiler will search for `foo' in the namespace of 'b'
2903 and find A::foo. GDB now supports this. This construct is commonly
2904 used in the Standard Template Library for operators.
2906 ** Improved User Defined Operator Support
2908 In addition to member operators, GDB now supports lookup of operators
2909 defined in a namespace and imported with a `using' directive, operators
2910 defined in the global scope, operators imported implicitly from an
2911 anonymous namespace, and the ADL operators mentioned in the previous
2913 GDB now also supports proper overload resolution for all the previously
2914 mentioned flavors of operators.
2916 ** static const class members
2918 Printing of static const class members that are initialized in the
2919 class definition has been fixed.
2921 * Windows Thread Information Block access.
2923 On Windows targets, GDB now supports displaying the Windows Thread
2924 Information Block (TIB) structure. This structure is visible either
2925 by using the new command `info w32 thread-information-block' or, by
2926 dereferencing the new convenience variable named `$_tlb', a
2927 thread-specific pointer to the TIB. This feature is also supported
2928 when remote debugging using GDBserver.
2930 * Static tracepoints
2932 Static tracepoints are calls in the user program into a tracing
2933 library. One such library is a port of the LTTng kernel tracer to
2934 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2935 When debugging with GDBserver, GDB now supports combining the GDB
2936 tracepoint machinery with such libraries. For example: the user can
2937 use GDB to probe a static tracepoint marker (a call from the user
2938 program into the tracing library) with the new "strace" command (see
2939 "New commands" below). This creates a "static tracepoint" in the
2940 breakpoint list, that can be manipulated with the same feature set
2941 as fast and regular tracepoints. E.g., collect registers, local and
2942 global variables, collect trace state variables, and define
2943 tracepoint conditions. In addition, the user can collect extra
2944 static tracepoint marker specific data, by collecting the new
2945 $_sdata internal variable. When analyzing the trace buffer, you can
2946 inspect $_sdata like any other variable available to GDB. For more
2947 information, see the "Tracepoints" chapter in GDB user manual. New
2948 remote packets have been defined to support static tracepoints, see
2949 the "New remote packets" section below.
2951 * Better reconstruction of tracepoints after disconnected tracing
2953 GDB will attempt to download the original source form of tracepoint
2954 definitions when starting a trace run, and then will upload these
2955 upon reconnection to the target, resulting in a more accurate
2956 reconstruction of the tracepoints that are in use on the target.
2960 You can now exercise direct control over the ways that GDB can
2961 affect your program. For instance, you can disallow the setting of
2962 breakpoints, so that the program can run continuously (assuming
2963 non-stop mode). In addition, the "observer" variable is available
2964 to switch all of the different controls; in observer mode, GDB
2965 cannot affect the target's behavior at all, which is useful for
2966 tasks like diagnosing live systems in the field.
2968 * The new convenience variable $_thread holds the number of the
2971 * New remote packets
2975 Return the address of the Windows Thread Information Block of a given thread.
2979 In response to several of the tracepoint packets, the target may now
2980 also respond with a number of intermediate `qRelocInsn' request
2981 packets before the final result packet, to have GDB handle
2982 relocating an instruction to execute at a different address. This
2983 is particularly useful for stubs that support fast tracepoints. GDB
2984 reports support for this feature in the qSupported packet.
2988 List static tracepoint markers in the target program.
2992 List static tracepoint markers at a given address in the target
2995 qXfer:statictrace:read
2997 Read the static trace data collected (by a `collect $_sdata'
2998 tracepoint action). The remote stub reports support for this packet
2999 to gdb's qSupported query.
3003 Send the current settings of GDB's permission flags.
3007 Send part of the source (textual) form of a tracepoint definition,
3008 which includes location, conditional, and action list.
3010 * The source command now accepts a -s option to force searching for the
3011 script in the source search path even if the script name specifies
3014 * New features in the GDB remote stub, GDBserver
3016 - GDBserver now support tracepoints (including fast tracepoints, and
3017 static tracepoints). The feature is currently supported by the
3018 i386-linux and amd64-linux builds. See the "Tracepoints support
3019 in gdbserver" section in the manual for more information.
3021 GDBserver JIT compiles the tracepoint's conditional agent
3022 expression bytecode into native code whenever possible for low
3023 overhead dynamic tracepoints conditionals. For such tracepoints,
3024 an expression that examines program state is evaluated when the
3025 tracepoint is reached, in order to determine whether to capture
3026 trace data. If the condition is simple and false, processing the
3027 tracepoint finishes very quickly and no data is gathered.
3029 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3030 for static tracepoints support.
3032 - GDBserver now supports x86_64 Windows 64-bit debugging.
3034 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3035 it understands register description.
3037 * The --batch flag now disables pagination and queries.
3039 * X86 general purpose registers
3041 GDB now supports reading/writing byte, word and double-word x86
3042 general purpose registers directly. This means you can use, say,
3043 $ah or $ax to refer, respectively, to the byte register AH and
3044 16-bit word register AX that are actually portions of the 32-bit
3045 register EAX or 64-bit register RAX.
3047 * The `commands' command now accepts a range of breakpoints to modify.
3048 A plain `commands' following a command that creates multiple
3049 breakpoints affects all the breakpoints set by that command. This
3050 applies to breakpoints set by `rbreak', and also applies when a
3051 single `break' command creates multiple breakpoints (e.g.,
3052 breakpoints on overloaded c++ functions).
3054 * The `rbreak' command now accepts a filename specification as part of
3055 its argument, limiting the functions selected by the regex to those
3056 in the specified file.
3058 * Support for remote debugging Windows and SymbianOS shared libraries
3059 from Unix hosts has been improved. Non Windows GDB builds now can
3060 understand target reported file names that follow MS-DOS based file
3061 system semantics, such as file names that include drive letters and
3062 use the backslash character as directory separator. This makes it
3063 possible to transparently use the "set sysroot" and "set
3064 solib-search-path" on Unix hosts to point as host copies of the
3065 target's shared libraries. See the new command "set
3066 target-file-system-kind" described below, and the "Commands to
3067 specify files" section in the user manual for more information.
3071 eval template, expressions...
3072 Convert the values of one or more expressions under the control
3073 of the string template to a command line, and call it.
3075 set target-file-system-kind unix|dos-based|auto
3076 show target-file-system-kind
3077 Set or show the assumed file system kind for target reported file
3080 save breakpoints <filename>
3081 Save all current breakpoint definitions to a file suitable for use
3082 in a later debugging session. To read the saved breakpoint
3083 definitions, use the `source' command.
3085 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3088 info static-tracepoint-markers
3089 Display information about static tracepoint markers in the target.
3091 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3092 Define a static tracepoint by probing a marker at the given
3093 function, line, address, or marker ID.
3097 Enable and disable observer mode.
3099 set may-write-registers on|off
3100 set may-write-memory on|off
3101 set may-insert-breakpoints on|off
3102 set may-insert-tracepoints on|off
3103 set may-insert-fast-tracepoints on|off
3104 set may-interrupt on|off
3105 Set individual permissions for GDB effects on the target. Note that
3106 some of these settings can have undesirable or surprising
3107 consequences, particularly when changed in the middle of a session.
3108 For instance, disabling the writing of memory can prevent
3109 breakpoints from being inserted, cause single-stepping to fail, or
3110 even crash your program, if you disable after breakpoints have been
3111 inserted. However, GDB should not crash.
3113 set record memory-query on|off
3114 show record memory-query
3115 Control whether to stop the inferior if memory changes caused
3116 by an instruction cannot be recorded.
3121 The disassemble command now supports "start,+length" form of two arguments.
3125 ** GDB now provides a new directory location, called the python directory,
3126 where Python scripts written for GDB can be installed. The location
3127 of that directory is <data-directory>/python, where <data-directory>
3128 is the GDB data directory. For more details, see section `Scripting
3129 GDB using Python' in the manual.
3131 ** The GDB Python API now has access to breakpoints, symbols, symbol
3132 tables, program spaces, inferiors, threads and frame's code blocks.
3133 Additionally, GDB Parameters can now be created from the API, and
3134 manipulated via set/show in the CLI.
3136 ** New functions gdb.target_charset, gdb.target_wide_charset,
3137 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3139 ** New exception gdb.GdbError.
3141 ** Pretty-printers are now also looked up in the current program space.
3143 ** Pretty-printers can now be individually enabled and disabled.
3145 ** GDB now looks for names of Python scripts to auto-load in a
3146 special section named `.debug_gdb_scripts', in addition to looking
3147 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3149 * Tracepoint actions were unified with breakpoint commands. In particular,
3150 there are no longer differences in "info break" output for breakpoints and
3151 tracepoints and the "commands" command can be used for both tracepoints and
3152 regular breakpoints.
3156 ARM Symbian arm*-*-symbianelf*
3158 * D language support.
3159 GDB now supports debugging programs written in the D programming
3162 * GDB now supports the extended ptrace interface for PowerPC which is
3163 available since Linux kernel version 2.6.34. This automatically enables
3164 any hardware breakpoints and additional hardware watchpoints available in
3165 the processor. The old ptrace interface exposes just one hardware
3166 watchpoint and no hardware breakpoints.
3168 * GDB is now able to use the Data Value Compare (DVC) register available on
3169 embedded PowerPC processors to implement in hardware simple watchpoint
3170 conditions of the form:
3172 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3174 This works in native GDB running on Linux kernels with the extended ptrace
3175 interface mentioned above.
3177 *** Changes in GDB 7.1
3181 ** Namespace Support
3183 GDB now supports importing of namespaces in C++. This enables the
3184 user to inspect variables from imported namespaces. Support for
3185 namepace aliasing has also been added. So, if a namespace is
3186 aliased in the current scope (e.g. namepace C=A; ) the user can
3187 print variables using the alias (e.g. (gdb) print C::x).
3191 All known bugs relating to the printing of virtual base class were
3192 fixed. It is now possible to call overloaded static methods using a
3197 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3198 and reinterpret_cast<> are now handled by the C++ expression parser.
3202 Xilinx MicroBlaze microblaze-*-*
3207 Xilinx MicroBlaze microblaze
3210 * Multi-program debugging.
3212 GDB now has support for multi-program (a.k.a. multi-executable or
3213 multi-exec) debugging. This allows for debugging multiple inferiors
3214 simultaneously each running a different program under the same GDB
3215 session. See "Debugging Multiple Inferiors and Programs" in the
3216 manual for more information. This implied some user visible changes
3217 in the multi-inferior support. For example, "info inferiors" now
3218 lists inferiors that are not running yet or that have exited
3219 already. See also "New commands" and "New options" below.
3221 * New tracing features
3223 GDB's tracepoint facility now includes several new features:
3225 ** Trace state variables
3227 GDB tracepoints now include support for trace state variables, which
3228 are variables managed by the target agent during a tracing
3229 experiment. They are useful for tracepoints that trigger each
3230 other, so for instance one tracepoint can count hits in a variable,
3231 and then a second tracepoint has a condition that is true when the
3232 count reaches a particular value. Trace state variables share the
3233 $-syntax of GDB convenience variables, and can appear in both
3234 tracepoint actions and condition expressions. Use the "tvariable"
3235 command to create, and "info tvariables" to view; see "Trace State
3236 Variables" in the manual for more detail.
3240 GDB now includes an option for defining fast tracepoints, which
3241 targets may implement more efficiently, such as by installing a jump
3242 into the target agent rather than a trap instruction. The resulting
3243 speedup can be by two orders of magnitude or more, although the
3244 tradeoff is that some program locations on some target architectures
3245 might not allow fast tracepoint installation, for instance if the
3246 instruction to be replaced is shorter than the jump. To request a
3247 fast tracepoint, use the "ftrace" command, with syntax identical to
3248 the regular trace command.
3250 ** Disconnected tracing
3252 It is now possible to detach GDB from the target while it is running
3253 a trace experiment, then reconnect later to see how the experiment
3254 is going. In addition, a new variable disconnected-tracing lets you
3255 tell the target agent whether to continue running a trace if the
3256 connection is lost unexpectedly.
3260 GDB now has the ability to save the trace buffer into a file, and
3261 then use that file as a target, similarly to you can do with
3262 corefiles. You can select trace frames, print data that was
3263 collected in them, and use tstatus to display the state of the
3264 tracing run at the moment that it was saved. To create a trace
3265 file, use "tsave <filename>", and to use it, do "target tfile
3268 ** Circular trace buffer
3270 You can ask the target agent to handle the trace buffer as a
3271 circular buffer, discarding the oldest trace frames to make room for
3272 newer ones, by setting circular-trace-buffer to on. This feature may
3273 not be available for all target agents.
3278 The disassemble command, when invoked with two arguments, now requires
3279 the arguments to be comma-separated.
3282 The info variables command now displays variable definitions. Files
3283 which only declare a variable are not shown.
3286 The source command is now capable of sourcing Python scripts.
3287 This feature is dependent on the debugger being build with Python
3290 Related to this enhancement is also the introduction of a new command
3291 "set script-extension" (see below).
3293 * New commands (for set/show, see "New options" below)
3295 record save [<FILENAME>]
3296 Save a file (in core file format) containing the process record
3297 execution log for replay debugging at a later time.
3299 record restore <FILENAME>
3300 Restore the process record execution log that was saved at an
3301 earlier time, for replay debugging.
3303 add-inferior [-copies <N>] [-exec <FILENAME>]
3306 clone-inferior [-copies <N>] [ID]
3307 Make a new inferior ready to execute the same program another
3308 inferior has loaded.
3313 maint info program-spaces
3314 List the program spaces loaded into GDB.
3316 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3317 show remote interrupt-sequence
3318 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3319 as the sequence to the remote target in order to interrupt the execution.
3320 Ctrl-C is a default. Some system prefers BREAK which is high level of
3321 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3322 Magic SysRq g. It is BREAK signal and character 'g'.
3324 set remote interrupt-on-connect [on | off]
3325 show remote interrupt-on-connect
3326 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3327 remote target when gdb connects to it. This is needed when you debug
3330 set remotebreak [on | off]
3332 Deprecated. Use "set/show remote interrupt-sequence" instead.
3334 tvariable $NAME [ = EXP ]
3335 Create or modify a trace state variable.
3338 List trace state variables and their values.
3340 delete tvariable $NAME ...
3341 Delete one or more trace state variables.
3344 Evaluate the given expressions without collecting anything into the
3345 trace buffer. (Valid in tracepoint actions only.)
3347 ftrace FN / FILE:LINE / *ADDR
3348 Define a fast tracepoint at the given function, line, or address.
3350 * New expression syntax
3352 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3353 GDB now parses 0b101010 identically with 42.
3357 set follow-exec-mode new|same
3358 show follow-exec-mode
3359 Control whether GDB reuses the same inferior across an exec call or
3360 creates a new one. This is useful to be able to restart the old
3361 executable after the inferior having done an exec call.
3363 set default-collect EXPR, ...
3364 show default-collect
3365 Define a list of expressions to be collected at each tracepoint.
3366 This is a useful way to ensure essential items are not overlooked,
3367 such as registers or a critical global variable.
3369 set disconnected-tracing
3370 show disconnected-tracing
3371 If set to 1, the target is instructed to continue tracing if it
3372 loses its connection to GDB. If 0, the target is to stop tracing
3375 set circular-trace-buffer
3376 show circular-trace-buffer
3377 If set to on, the target is instructed to use a circular trace buffer
3378 and discard the oldest trace frames instead of stopping the trace due
3379 to a full trace buffer. If set to off, the trace stops when the buffer
3380 fills up. Some targets may not support this.
3382 set script-extension off|soft|strict
3383 show script-extension
3384 If set to "off", the debugger does not perform any script language
3385 recognition, and all sourced files are assumed to be GDB scripts.
3386 If set to "soft" (the default), files are sourced according to
3387 filename extension, falling back to GDB scripts if the first
3389 If set to "strict", files are sourced according to filename extension.
3391 set ada trust-PAD-over-XVS on|off
3392 show ada trust-PAD-over-XVS
3393 If off, activate a workaround against a bug in the debugging information
3394 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3395 the GCC sources for more information about the GNAT encoding and
3396 PAD types in particular). It is always safe to set this option to
3397 off, but this introduces a slight performance penalty. The default
3400 * Python API Improvements
3402 ** GDB provides the new class gdb.LazyString. This is useful in
3403 some pretty-printing cases. The new method gdb.Value.lazy_string
3404 provides a simple way to create objects of this type.
3406 ** The fields returned by gdb.Type.fields now have an
3407 `is_base_class' attribute.
3409 ** The new method gdb.Type.range returns the range of an array type.
3411 ** The new method gdb.parse_and_eval can be used to parse and
3412 evaluate an expression.
3414 * New remote packets
3417 Define a trace state variable.
3420 Get the current value of a trace state variable.
3423 Set desired tracing behavior upon disconnection.
3426 Set the trace buffer to be linear or circular.
3429 Get data about the tracepoints currently in use.
3433 Process record now works correctly with hardware watchpoints.
3435 Multiple bug fixes have been made to the mips-irix port, making it
3436 much more reliable. In particular:
3437 - Debugging threaded applications is now possible again. Previously,
3438 GDB would hang while starting the program, or while waiting for
3439 the program to stop at a breakpoint.
3440 - Attaching to a running process no longer hangs.
3441 - An error occurring while loading a core file has been fixed.
3442 - Changing the value of the PC register now works again. This fixes
3443 problems observed when using the "jump" command, or when calling
3444 a function from GDB, or even when assigning a new value to $pc.
3445 - With the "finish" and "return" commands, the return value for functions
3446 returning a small array is now correctly printed.
3447 - It is now possible to break on shared library code which gets executed
3448 during a shared library init phase (code executed while executing
3449 their .init section). Previously, the breakpoint would have no effect.
3450 - GDB is now able to backtrace through the signal handler for
3451 non-threaded programs.
3453 PIE (Position Independent Executable) programs debugging is now supported.
3454 This includes debugging execution of PIC (Position Independent Code) shared
3455 libraries although for that, it should be possible to run such libraries as an
3458 *** Changes in GDB 7.0
3460 * GDB now has an interface for JIT compilation. Applications that
3461 dynamically generate code can create symbol files in memory and register
3462 them with GDB. For users, the feature should work transparently, and
3463 for JIT developers, the interface is documented in the GDB manual in the
3464 "JIT Compilation Interface" chapter.
3466 * Tracepoints may now be conditional. The syntax is as for
3467 breakpoints; either an "if" clause appended to the "trace" command,
3468 or the "condition" command is available. GDB sends the condition to
3469 the target for evaluation using the same bytecode format as is used
3470 for tracepoint actions.
3472 * The disassemble command now supports: an optional /r modifier, print the
3473 raw instructions in hex as well as in symbolic form, and an optional /m
3474 modifier to print mixed source+assembly.
3476 * Process record and replay
3478 In a architecture environment that supports ``process record and
3479 replay'', ``process record and replay'' target can record a log of
3480 the process execution, and replay it with both forward and reverse
3483 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3484 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3485 set execution-direction {forward|reverse}, for targets that support
3488 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3489 feature is available with a native GDB running on kernel version
3492 * GDB now has support for multi-byte and wide character sets on the
3493 target. Strings whose character type is wchar_t, char16_t, or
3494 char32_t are now correctly printed. GDB supports wide- and unicode-
3495 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3496 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3497 `printf'. This feature requires iconv to work properly; if your
3498 system does not have a working iconv, GDB can use GNU libiconv. See
3499 the installation instructions for more information.
3501 * GDB now supports automatic retrieval of shared library files from
3502 remote targets. To use this feature, specify a system root that begins
3503 with the `remote:' prefix, either via the `set sysroot' command or via
3504 the `--with-sysroot' configure-time option.
3506 * "info sharedlibrary" now takes an optional regex of libraries to show,
3507 and it now reports if a shared library has no debugging information.
3509 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3510 now complete on file names.
3512 * When completing in expressions, gdb will attempt to limit
3513 completions to allowable structure or union fields, where appropriate.
3514 For instance, consider:
3516 # struct example { int f1; double f2; };
3517 # struct example variable;
3520 If the user types TAB at the end of this command line, the available
3521 completions will be "f1" and "f2".
3523 * Inlined functions are now supported. They show up in backtraces, and
3524 the "step", "next", and "finish" commands handle them automatically.
3526 * GDB now supports the token-splicing (##) and stringification (#)
3527 operators when expanding macros. It also supports variable-arity
3530 * GDB now supports inspecting extra signal information, exported by
3531 the new $_siginfo convenience variable. The feature is currently
3532 implemented on linux ARM, i386 and amd64.
3534 * GDB can now display the VFP floating point registers and NEON vector
3535 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3536 can provide these registers (requires Linux 2.6.30 or later). Remote
3537 and simulator targets may also provide them.
3539 * New remote packets
3542 Search memory for a sequence of bytes.
3545 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3546 operation over reliable transport links. Use of this packet is
3547 controlled by the `set remote noack-packet' command.
3550 Kill the process with the specified process ID. Use this in preference
3551 to `k' when multiprocess protocol extensions are supported.
3554 Obtains additional operating system information
3558 Read or write additional signal information.
3560 * Removed remote protocol undocumented extension
3562 An undocumented extension to the remote protocol's `S' stop reply
3563 packet that permited the stub to pass a process id was removed.
3564 Remote servers should use the `T' stop reply packet instead.
3566 * GDB now supports multiple function calling conventions according to the
3567 DWARF-2 DW_AT_calling_convention function attribute.
3569 * The SH target utilizes the aforementioned change to distinguish between gcc
3570 and Renesas calling convention. It also adds the new CLI commands
3571 `set/show sh calling-convention'.
3573 * GDB can now read compressed debug sections, as produced by GNU gold
3574 with the --compress-debug-sections=zlib flag.
3576 * 64-bit core files are now supported on AIX.
3578 * Thread switching is now supported on Tru64.
3580 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3581 which will be allocated using malloc later in program execution.
3583 * The qXfer:libraries:read remote procotol packet now allows passing a
3584 list of section offsets.
3586 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3587 conditions handling signals delivered during attach or thread creation
3588 have also been fixed.
3590 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3591 From the user's standpoint, all unqualified instances of True and False
3592 are treated as the standard definitions, regardless of context.
3594 * GDB now parses C++ symbol and type names more flexibly. For
3597 template<typename T> class C { };
3600 GDB will now correctly handle all of:
3602 ptype C<char const *>
3603 ptype C<char const*>
3604 ptype C<const char *>
3605 ptype C<const char*>
3607 * New features in the GDB remote stub, gdbserver
3609 - The "--wrapper" command-line argument tells gdbserver to use a
3610 wrapper program to launch programs for debugging.
3612 - On PowerPC and S/390 targets, it is now possible to use a single
3613 gdbserver executable to debug both 32-bit and 64-bit programs.
3614 (This requires gdbserver itself to be built as a 64-bit executable.)
3616 - gdbserver uses the new noack protocol mode for TCP connections to
3617 reduce communications latency, if also supported and enabled in GDB.
3619 - Support for the sparc64-linux-gnu target is now included in
3622 - The amd64-linux build of gdbserver now supports debugging both
3623 32-bit and 64-bit programs.
3625 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3626 now support hardware watchpoints, and will use them automatically
3631 GDB now has support for scripting using Python. Whether this is
3632 available is determined at configure time.
3634 New GDB commands can now be written in Python.
3636 * Ada tasking support
3638 Ada tasks can now be inspected in GDB. The following commands have
3642 Print the list of Ada tasks.
3644 Print detailed information about task number N.
3646 Print the task number of the current task.
3648 Switch the context of debugging to task number N.
3650 * Support for user-defined prefixed commands. The "define" command can
3651 add new commands to existing prefixes, e.g. "target".
3653 * Multi-inferior, multi-process debugging.
3655 GDB now has generalized support for multi-inferior debugging. See
3656 "Debugging Multiple Inferiors" in the manual for more information.
3657 Although availability still depends on target support, the command
3658 set is more uniform now. The GNU/Linux specific multi-forks support
3659 has been migrated to this new framework. This implied some user
3660 visible changes; see "New commands" and also "Removed commands"
3663 * Target descriptions can now describe the target OS ABI. See the
3664 "Target Description Format" section in the user manual for more
3667 * Target descriptions can now describe "compatible" architectures
3668 to indicate that the target can execute applications for a different
3669 architecture in addition to those for the main target architecture.
3670 See the "Target Description Format" section in the user manual for
3673 * Multi-architecture debugging.
3675 GDB now includes general supports for debugging applications on
3676 hybrid systems that use more than one single processor architecture
3677 at the same time. Each such hybrid architecture still requires
3678 specific support to be added. The only hybrid architecture supported
3679 in this version of GDB is the Cell Broadband Engine.
3681 * GDB now supports integrated debugging of Cell/B.E. applications that
3682 use both the PPU and SPU architectures. To enable support for hybrid
3683 Cell/B.E. debugging, you need to configure GDB to support both the
3684 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3685 --enable-targets configure option.
3687 * Non-stop mode debugging.
3689 For some targets, GDB now supports an optional mode of operation in
3690 which you can examine stopped threads while other threads continue
3691 to execute freely. This is referred to as non-stop mode, with the
3692 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3693 section in the user manual for more information.
3695 To be able to support remote non-stop debugging, a remote stub needs
3696 to implement the non-stop mode remote protocol extensions, as
3697 described in the "Remote Non-Stop" section of the user manual. The
3698 GDB remote stub, gdbserver, has been adjusted to support these
3699 extensions on linux targets.
3701 * New commands (for set/show, see "New options" below)
3703 catch syscall [NAME(S) | NUMBER(S)]
3704 Catch system calls. Arguments, which should be names of system
3705 calls or their numbers, mean catch only those syscalls. Without
3706 arguments, every syscall will be caught. When the inferior issues
3707 any of the specified syscalls, GDB will stop and announce the system
3708 call, both when it is called and when its call returns. This
3709 feature is currently available with a native GDB running on the
3710 Linux Kernel, under the following architectures: x86, x86_64,
3711 PowerPC and PowerPC64.
3713 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3715 Search memory for a sequence of bytes.
3717 maint set python print-stack
3718 maint show python print-stack
3719 Show a stack trace when an error is encountered in a Python script.
3722 Invoke CODE by passing it to the Python interpreter.
3727 These allow macros to be defined, undefined, and listed
3731 Show operating system information about processes.
3734 List the inferiors currently under GDB's control.
3737 Switch focus to inferior number NUM.
3740 Detach from inferior number NUM.
3743 Kill inferior number NUM.
3747 set spu stop-on-load
3748 show spu stop-on-load
3749 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3751 set spu auto-flush-cache
3752 show spu auto-flush-cache
3753 Control whether to automatically flush the software-managed cache
3754 during Cell/B.E. debugging.
3756 set sh calling-convention
3757 show sh calling-convention
3758 Control the calling convention used when calling SH target functions.
3761 show debug timestamp
3762 Control display of timestamps with GDB debugging output.
3764 set disassemble-next-line
3765 show disassemble-next-line
3766 Control display of disassembled source lines or instructions when
3769 set remote noack-packet
3770 show remote noack-packet
3771 Set/show the use of remote protocol QStartNoAckMode packet. See above
3772 under "New remote packets."
3774 set remote query-attached-packet
3775 show remote query-attached-packet
3776 Control use of remote protocol `qAttached' (query-attached) packet.
3778 set remote read-siginfo-object
3779 show remote read-siginfo-object
3780 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3783 set remote write-siginfo-object
3784 show remote write-siginfo-object
3785 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3788 set remote reverse-continue
3789 show remote reverse-continue
3790 Control use of remote protocol 'bc' (reverse-continue) packet.
3792 set remote reverse-step
3793 show remote reverse-step
3794 Control use of remote protocol 'bs' (reverse-step) packet.
3796 set displaced-stepping
3797 show displaced-stepping
3798 Control displaced stepping mode. Displaced stepping is a way to
3799 single-step over breakpoints without removing them from the debuggee.
3800 Also known as "out-of-line single-stepping".
3803 show debug displaced
3804 Control display of debugging info for displaced stepping.
3806 maint set internal-error
3807 maint show internal-error
3808 Control what GDB does when an internal error is detected.
3810 maint set internal-warning
3811 maint show internal-warning
3812 Control what GDB does when an internal warning is detected.
3817 Use a wrapper program to launch programs for debugging.
3819 set multiple-symbols (all|ask|cancel)
3820 show multiple-symbols
3821 The value of this variable can be changed to adjust the debugger behavior
3822 when an expression or a breakpoint location contains an ambiguous symbol
3823 name (an overloaded function name, for instance).
3825 set breakpoint always-inserted
3826 show breakpoint always-inserted
3827 Keep breakpoints always inserted in the target, as opposed to inserting
3828 them when resuming the target, and removing them when the target stops.
3829 This option can improve debugger performance on slow remote targets.
3831 set arm fallback-mode (arm|thumb|auto)
3832 show arm fallback-mode
3833 set arm force-mode (arm|thumb|auto)
3835 These commands control how ARM GDB determines whether instructions
3836 are ARM or Thumb. The default for both settings is auto, which uses
3837 the current CPSR value for instructions without symbols; previous
3838 versions of GDB behaved as if "set arm fallback-mode arm".
3840 set disable-randomization
3841 show disable-randomization
3842 Standalone programs run with the virtual address space randomization enabled
3843 by default on some platforms. This option keeps the addresses stable across
3844 multiple debugging sessions.
3848 Control whether other threads are stopped or not when some thread hits
3853 Requests that asynchronous execution is enabled in the target, if available.
3854 In this case, it's possible to resume target in the background, and interact
3855 with GDB while the target is running. "show target-async" displays the
3856 current state of asynchronous execution of the target.
3858 set target-wide-charset
3859 show target-wide-charset
3860 The target-wide-charset is the name of the character set that GDB
3861 uses when printing characters whose type is wchar_t.
3863 set tcp auto-retry (on|off)
3865 set tcp connect-timeout
3866 show tcp connect-timeout
3867 These commands allow GDB to retry failed TCP connections to a remote stub
3868 with a specified timeout period; this is useful if the stub is launched
3869 in parallel with GDB but may not be ready to accept connections immediately.
3871 set libthread-db-search-path
3872 show libthread-db-search-path
3873 Control list of directories which GDB will search for appropriate
3876 set schedule-multiple (on|off)
3877 show schedule-multiple
3878 Allow GDB to resume all threads of all processes or only threads of
3879 the current process.
3883 Use more aggressive caching for accesses to the stack. This improves
3884 performance of remote debugging (particularly backtraces) without
3885 affecting correctness.
3887 set interactive-mode (on|off|auto)
3888 show interactive-mode
3889 Control whether GDB runs in interactive mode (on) or not (off).
3890 When in interactive mode, GDB waits for the user to answer all
3891 queries. Otherwise, GDB does not wait and assumes the default
3892 answer. When set to auto (the default), GDB determines which
3893 mode to use based on the stdin settings.
3898 For program forks, this is replaced by the new more generic `info
3899 inferiors' command. To list checkpoints, you can still use the
3900 `info checkpoints' command, which was an alias for the `info forks'
3904 Replaced by the new `inferior' command. To switch between
3905 checkpoints, you can still use the `restart' command, which was an
3906 alias for the `fork' command.
3909 This is removed, since some targets don't have a notion of
3910 processes. To switch between processes, you can still use the
3911 `inferior' command using GDB's own inferior number.
3914 For program forks, this is replaced by the new more generic `kill
3915 inferior' command. To delete a checkpoint, you can still use the
3916 `delete checkpoint' command, which was an alias for the `delete
3920 For program forks, this is replaced by the new more generic `detach
3921 inferior' command. To detach a checkpoint, you can still use the
3922 `detach checkpoint' command, which was an alias for the `detach
3925 * New native configurations
3927 x86/x86_64 Darwin i[34567]86-*-darwin*
3929 x86_64 MinGW x86_64-*-mingw*
3933 Lattice Mico32 lm32-*
3934 x86 DICOS i[34567]86-*-dicos*
3935 x86_64 DICOS x86_64-*-dicos*
3938 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3939 (mingw32ce) debugging.
3945 These commands were actually not implemented on any target.
3947 *** Changes in GDB 6.8
3949 * New native configurations
3951 NetBSD/hppa hppa*-*netbsd*
3952 Xtensa GNU/Linux xtensa*-*-linux*
3956 NetBSD/hppa hppa*-*-netbsd*
3957 Xtensa GNU/Lunux xtensa*-*-linux*
3959 * Change in command line behavior -- corefiles vs. process ids.
3961 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3962 attaching to process NUMBER fails, GDB no longer attempts to open a
3963 core file named NUMBER. Attaching to a program using the -c option
3964 is no longer supported. Instead, use the '-p' or '--pid' options.
3966 * GDB can now be built as a native debugger for debugging Windows x86
3967 (mingw32) Portable Executable (PE) programs.
3969 * Pending breakpoints no longer change their number when their address
3972 * GDB now supports breakpoints with multiple locations,
3973 including breakpoints on C++ constructors, inside C++ templates,
3974 and in inlined functions.
3976 * GDB's ability to debug optimized code has been improved. GDB more
3977 accurately identifies function bodies and lexical blocks that occupy
3978 more than one contiguous range of addresses.
3980 * Target descriptions can now describe registers for PowerPC.
3982 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3983 registers on PowerPC targets.
3985 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3986 targets even when the libthread_db library is not available.
3988 * The GDB remote stub, gdbserver, now supports the new file transfer
3989 commands (remote put, remote get, and remote delete).
3991 * The GDB remote stub, gdbserver, now supports run and attach in
3992 extended-remote mode.
3994 * hppa*64*-*-hpux11* target broken
3995 The debugger is unable to start a program and fails with the following
3996 error: "Error trying to get information about dynamic linker".
3997 The gdb-6.7 release is also affected.
3999 * GDB now supports the --enable-targets= configure option to allow
4000 building a single GDB executable that supports multiple remote
4001 target architectures.
4003 * GDB now supports debugging C and C++ programs which use the
4004 Decimal Floating Point extension. In addition, the PowerPC target
4005 now has a set of pseudo-registers to inspect decimal float values
4006 stored in two consecutive float registers.
4008 * The -break-insert MI command can optionally create pending
4011 * Improved support for debugging Ada
4012 Many improvements to the Ada language support have been made. These
4014 - Better support for Ada2005 interface types
4015 - Improved handling of arrays and slices in general
4016 - Better support for Taft-amendment types
4017 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4019 - Improved command completion in Ada
4022 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4027 set print frame-arguments (all|scalars|none)
4028 show print frame-arguments
4029 The value of this variable can be changed to control which argument
4030 values should be printed by the debugger when displaying a frame.
4035 Transfer files to and from a remote target, and delete remote files.
4042 Transfer files to and from a remote target, and delete remote files.
4044 * New remote packets
4051 Open, close, read, write, and delete files on the remote system.
4054 Attach to an existing process on the remote system, in extended-remote
4058 Run a new process on the remote system, in extended-remote mode.
4060 *** Changes in GDB 6.7
4062 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4063 bfd, libiberty and opcodes, as revealed by static analysis donated by
4064 Coverity, Inc. (http://scan.coverity.com).
4066 * When looking up multiply-defined global symbols, GDB will now prefer the
4067 symbol definition in the current shared library if it was built using the
4068 -Bsymbolic linker option.
4070 * When the Text User Interface (TUI) is not configured, GDB will now
4071 recognize the -tui command-line option and print a message that the TUI
4074 * The GDB remote stub, gdbserver, now has lower overhead for high
4075 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4077 * GDB for MIPS targets now autodetects whether a remote target provides
4078 32-bit or 64-bit register values.
4080 * Support for C++ member pointers has been improved.
4082 * GDB now understands XML target descriptions, which specify the
4083 target's overall architecture. GDB can read a description from
4084 a local file or over the remote serial protocol.
4086 * Vectors of single-byte data use a new integer type which is not
4087 automatically displayed as character or string data.
4089 * The /s format now works with the print command. It displays
4090 arrays of single-byte integers and pointers to single-byte integers
4093 * Target descriptions can now describe target-specific registers,
4094 for architectures which have implemented the support (currently
4095 only ARM, M68K, and MIPS).
4097 * GDB and the GDB remote stub, gdbserver, now support the XScale
4100 * The GDB remote stub, gdbserver, has been updated to support
4101 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4102 has been rewritten to use the standard GDB remote protocol.
4104 * GDB can now step into C++ functions which are called through thunks.
4106 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4108 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4109 layout. It also supports a TextSeg= and DataSeg= response when only
4110 segment base addresses (rather than offsets) are available.
4112 * The /i format now outputs any trailing branch delay slot instructions
4113 immediately following the last instruction within the count specified.
4115 * The GDB remote protocol "T" stop reply packet now supports a
4116 "library" response. Combined with the new "qXfer:libraries:read"
4117 packet, this response allows GDB to debug shared libraries on targets
4118 where the operating system manages the list of loaded libraries (e.g.
4119 Windows and SymbianOS).
4121 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4122 (DLLs) on Windows and Windows CE targets.
4124 * GDB now supports a faster verification that a .debug file matches its binary
4125 according to its build-id signature, if the signature is present.
4131 Enable or disable hardware flow control (RTS/CTS) on the serial port
4132 when debugging using remote targets.
4134 set mem inaccessible-by-default
4135 show mem inaccessible-by-default
4136 If the target supplies a memory map, for instance via the remote
4137 protocol's "qXfer:memory-map:read" packet, setting this variable
4138 prevents GDB from accessing memory outside the memory map. This
4139 is useful for targets with memory mapped registers or which react
4140 badly to accesses of unmapped address space.
4142 set breakpoint auto-hw
4143 show breakpoint auto-hw
4144 If the target supplies a memory map, for instance via the remote
4145 protocol's "qXfer:memory-map:read" packet, setting this variable
4146 lets GDB use hardware breakpoints automatically for memory regions
4147 where it can not use software breakpoints. This covers both the
4148 "break" command and internal breakpoints used for other commands
4149 including "next" and "finish".
4152 catch exception unhandled
4153 Stop the program execution when Ada exceptions are raised.
4156 Stop the program execution when an Ada assertion failed.
4160 Set an alternate system root for target files. This is a more
4161 general version of "set solib-absolute-prefix", which is now
4162 an alias to "set sysroot".
4165 Provide extended SPU facility status information. This set of
4166 commands is available only when debugging the Cell/B.E. SPU
4169 * New native configurations
4171 OpenBSD/sh sh*-*openbsd*
4174 unset tdesc filename
4176 Use the specified local file as an XML target description, and do
4177 not query the target for its built-in description.
4181 OpenBSD/sh sh*-*-openbsd*
4182 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4183 Toshiba Media Processor mep-elf
4185 * New remote packets
4188 Ignore the specified signals; pass them directly to the debugged program
4189 without stopping other threads or reporting them to GDB.
4191 qXfer:features:read:
4192 Read an XML target description from the target, which describes its
4197 Read or write contents of an spufs file on the target system. These
4198 packets are available only on the Cell/B.E. SPU architecture.
4200 qXfer:libraries:read:
4201 Report the loaded shared libraries. Combined with new "T" packet
4202 response, this packet allows GDB to debug shared libraries on
4203 targets where the operating system manages the list of loaded
4204 libraries (e.g. Windows and SymbianOS).
4208 Support for these obsolete configurations has been removed.
4216 i[34567]86-*-lynxos*
4217 i[34567]86-*-netware*
4218 i[34567]86-*-sco3.2v5*
4219 i[34567]86-*-sco3.2v4*
4221 i[34567]86-*-sysv4.2*
4224 i[34567]86-*-unixware2*
4225 i[34567]86-*-unixware*
4234 * Other removed features
4241 Various m68k-only ROM monitors.
4248 Various Renesas ROM monitors and debugging interfaces for SH and
4253 Support for a Macraigor serial interface to on-chip debugging.
4254 GDB does not directly support the newer parallel or USB
4259 A debug information format. The predecessor to DWARF 2 and
4260 DWARF 3, which are still supported.
4262 Support for the HP aCC compiler on HP-UX/PA-RISC
4264 SOM-encapsulated symbolic debugging information, automatic
4265 invocation of pxdb, and the aCC custom C++ ABI. This does not
4266 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4267 with aCC can still be debugged on an assembly level.
4269 MIPS ".pdr" sections
4271 A MIPS-specific format used to describe stack frame layout
4272 in debugging information.
4276 GDB could work with an older version of Guile to debug
4277 the interpreter and Scheme programs running in it.
4279 set mips stack-arg-size
4280 set mips saved-gpreg-size
4282 Use "set mips abi" to control parameter passing for MIPS.
4284 *** Changes in GDB 6.6
4289 Cell Broadband Engine SPU spu-elf
4291 * GDB can now be configured as a cross-debugger targeting native Windows
4292 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4293 running on a Windows system over TCP/IP to debug Windows programs.
4295 * The GDB remote stub, gdbserver, has been updated to support Windows and
4296 Cygwin debugging. Both single-threaded and multi-threaded programs are
4299 * The "set trust-readonly-sections" command works again. This command was
4300 broken in GDB 6.3, 6.4, and 6.5.
4302 * The "load" command now supports writing to flash memory, if the remote
4303 stub provides the required support.
4305 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4306 longer requires symbolic debug information (e.g. DWARF-2).
4311 unset substitute-path
4312 show substitute-path
4313 Manage a list of substitution rules that GDB uses to rewrite the name
4314 of the directories where the sources are located. This can be useful
4315 for instance when the sources were moved to a different location
4316 between compilation and debugging.
4320 Print each CLI command as it is executed. Each command is prefixed with
4321 a number of `+' symbols representing the nesting depth.
4322 The source command now has a `-v' option to enable the same feature.
4326 The ARM Demon monitor support (RDP protocol, "target rdp").
4328 Kernel Object Display, an embedded debugging feature which only worked with
4329 an obsolete version of Cisco IOS.
4331 The 'set download-write-size' and 'show download-write-size' commands.
4333 * New remote packets
4336 Tell a stub about GDB client features, and request remote target features.
4337 The first feature implemented is PacketSize, which allows the target to
4338 specify the size of packets it can handle - to minimize the number of
4339 packets required and improve performance when connected to a remote
4343 Fetch an OS auxilliary vector from the remote stub. This packet is a
4344 more efficient replacement for qPart:auxv:read.
4346 qXfer:memory-map:read:
4347 Fetch a memory map from the remote stub, including information about
4348 RAM, ROM, and flash memory devices.
4353 Erase and program a flash memory device.
4355 * Removed remote packets
4358 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4359 used it, and only gdbserver implemented it.
4361 *** Changes in GDB 6.5
4365 Renesas M32C/M16C m32c-elf
4367 Morpho Technologies ms1 ms1-elf
4371 init-if-undefined Initialize a convenience variable, but
4372 only if it doesn't already have a value.
4374 The following commands are presently only implemented for native GNU/Linux:
4376 checkpoint Save a snapshot of the program state.
4378 restart <n> Return the program state to a
4379 previously saved state.
4381 info checkpoints List currently saved checkpoints.
4383 delete-checkpoint <n> Delete a previously saved checkpoint.
4385 set|show detach-on-fork Tell gdb whether to detach from a newly
4386 forked process, or to keep debugging it.
4388 info forks List forks of the user program that
4389 are available to be debugged.
4391 fork <n> Switch to debugging one of several
4392 forks of the user program that are
4393 available to be debugged.
4395 delete-fork <n> Delete a fork from the list of forks
4396 that are available to be debugged (and
4397 kill the forked process).
4399 detach-fork <n> Delete a fork from the list of forks
4400 that are available to be debugged (and
4401 allow the process to continue).
4405 Morpho Technologies ms2 ms1-elf
4407 * Improved Windows host support
4409 GDB now builds as a cross debugger hosted on i686-mingw32, including
4410 native console support, and remote communications using either
4411 network sockets or serial ports.
4413 * Improved Modula-2 language support
4415 GDB can now print most types in the Modula-2 syntax. This includes:
4416 basic types, set types, record types, enumerated types, range types,
4417 pointer types and ARRAY types. Procedure var parameters are correctly
4418 printed and hexadecimal addresses and character constants are also
4419 written in the Modula-2 syntax. Best results can be obtained by using
4420 GNU Modula-2 together with the -gdwarf-2 command line option.
4424 The ARM rdi-share module.
4426 The Netware NLM debug server.
4428 *** Changes in GDB 6.4
4430 * New native configurations
4432 OpenBSD/arm arm*-*-openbsd*
4433 OpenBSD/mips64 mips64-*-openbsd*
4437 Morpho Technologies ms1 ms1-elf
4439 * New command line options
4441 --batch-silent As for --batch, but totally silent.
4442 --return-child-result The debugger will exist with the same value
4443 the child (debugged) program exited with.
4444 --eval-command COMMAND, -ex COMMAND
4445 Execute a single GDB CLI command. This may be
4446 specified multiple times and in conjunction
4447 with the --command (-x) option.
4449 * Deprecated commands removed
4451 The following commands, that were deprecated in 2000, have been
4455 set|show arm disassembly-flavor set|show arm disassembler
4456 othernames set arm disassembler
4457 set|show remotedebug set|show debug remote
4458 set|show archdebug set|show debug arch
4459 set|show eventdebug set|show debug event
4462 * New BSD user-level threads support
4464 It is now possible to debug programs using the user-level threads
4465 library on OpenBSD and FreeBSD. Currently supported (target)
4468 FreeBSD/amd64 x86_64-*-freebsd*
4469 FreeBSD/i386 i386-*-freebsd*
4470 OpenBSD/i386 i386-*-openbsd*
4472 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4473 are not yet supported.
4475 * New support for Matsushita MN10300 w/sim added
4476 (Work in progress). mn10300-elf.
4478 * REMOVED configurations and files
4480 VxWorks and the XDR protocol *-*-vxworks
4481 Motorola MCORE mcore-*-*
4482 National Semiconductor NS32000 ns32k-*-*
4484 * New "set print array-indexes" command
4486 After turning this setting "on", GDB prints the index of each element
4487 when displaying arrays. The default is "off" to preserve the previous
4490 * VAX floating point support
4492 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4494 * User-defined command support
4496 In addition to using $arg0..$arg9 for argument passing, it is now possible
4497 to use $argc to determine now many arguments have been passed. See the
4498 section on user-defined commands in the user manual for more information.
4500 *** Changes in GDB 6.3:
4502 * New command line option
4504 GDB now accepts -l followed by a number to set the timeout for remote
4507 * GDB works with GCC -feliminate-dwarf2-dups
4509 GDB now supports a more compact representation of DWARF-2 debug
4510 information using DW_FORM_ref_addr references. These are produced
4511 by GCC with the option -feliminate-dwarf2-dups and also by some
4512 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4513 to use -feliminate-dwarf2-dups.
4515 * Internationalization
4517 When supported by the host system, GDB will be built with
4518 internationalization (libintl). The task of marking up the sources is
4519 continued, we're looking forward to our first translation.
4523 Initial support for debugging programs compiled with the GNAT
4524 implementation of the Ada programming language has been integrated
4525 into GDB. In this release, support is limited to expression evaluation.
4527 * New native configurations
4529 GNU/Linux/m32r m32r-*-linux-gnu
4533 GDB's remote protocol now includes support for the 'p' packet. This
4534 packet is used to fetch individual registers from a remote inferior.
4536 * END-OF-LIFE registers[] compatibility module
4538 GDB's internal register infrastructure has been completely rewritten.
4539 The new infrastructure making possible the implementation of key new
4540 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4543 GDB 6.3 will be the last release to include the the registers[]
4544 compatibility module that allowed out-of-date configurations to
4545 continue to work. This change directly impacts the following
4555 powerpc bdm protocol
4557 Unless there is activity to revive these configurations, they will be
4558 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4560 * OBSOLETE configurations and files
4562 Configurations that have been declared obsolete in this release have
4563 been commented out. Unless there is activity to revive these
4564 configurations, the next release of GDB will have their sources
4565 permanently REMOVED.
4574 *** Changes in GDB 6.2.1:
4576 * MIPS `break main; run' gave an heuristic-fence-post warning
4578 When attempting to run even a simple program, a warning about
4579 heuristic-fence-post being hit would be reported. This problem has
4582 * MIPS IRIX 'long double' crashed GDB
4584 When examining a long double variable, GDB would get a segmentation
4585 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4586 IRIX long double values).
4590 A bug in the VAX stack code was causing problems with the "next"
4591 command. This problem has been fixed.
4593 *** Changes in GDB 6.2:
4595 * Fix for ``many threads''
4597 On GNU/Linux systems that use the NPTL threads library, a program
4598 rapidly creating and deleting threads would confuse GDB leading to the
4601 ptrace: No such process.
4602 thread_db_get_info: cannot get thread info: generic error
4604 This problem has been fixed.
4606 * "-async" and "-noasync" options removed.
4608 Support for the broken "-noasync" option has been removed (it caused
4611 * New ``start'' command.
4613 This command runs the program until the begining of the main procedure.
4615 * New BSD Kernel Data Access Library (libkvm) interface
4617 Using ``target kvm'' it is now possible to debug kernel core dumps and
4618 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4619 platforms. Currently supported (native-only) configurations are:
4621 FreeBSD/amd64 x86_64-*-freebsd*
4622 FreeBSD/i386 i?86-*-freebsd*
4623 NetBSD/i386 i?86-*-netbsd*
4624 NetBSD/m68k m68*-*-netbsd*
4625 NetBSD/sparc sparc-*-netbsd*
4626 OpenBSD/amd64 x86_64-*-openbsd*
4627 OpenBSD/i386 i?86-*-openbsd*
4628 OpenBSD/m68k m68*-openbsd*
4629 OpenBSD/sparc sparc-*-openbsd*
4631 * Signal trampoline code overhauled
4633 Many generic problems with GDB's signal handling code have been fixed.
4634 These include: backtraces through non-contiguous stacks; recognition
4635 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4636 call; backtrace through a signal trampoline; step into and out of
4637 signal handlers; and single-stepping in the signal trampoline.
4639 Please note that kernel bugs are a limiting factor here. These
4640 features have been shown to work on an s390 GNU/Linux system that
4641 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4643 * Cygwin support for DWARF 2 added.
4645 * New native configurations
4647 GNU/Linux/hppa hppa*-*-linux*
4648 OpenBSD/hppa hppa*-*-openbsd*
4649 OpenBSD/m68k m68*-*-openbsd*
4650 OpenBSD/m88k m88*-*-openbsd*
4651 OpenBSD/powerpc powerpc-*-openbsd*
4652 NetBSD/vax vax-*-netbsd*
4653 OpenBSD/vax vax-*-openbsd*
4655 * END-OF-LIFE frame compatibility module
4657 GDB's internal frame infrastructure has been completely rewritten.
4658 The new infrastructure making it possible to support key new features
4659 including DWARF 2 Call Frame Information. To aid in the task of
4660 migrating old configurations to this new infrastructure, a
4661 compatibility module, that allowed old configurations to continue to
4662 work, was also included.
4664 GDB 6.2 will be the last release to include this frame compatibility
4665 module. This change directly impacts the following configurations:
4675 Unless there is activity to revive these configurations, they will be
4676 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4678 * REMOVED configurations and files
4680 Sun 3, running SunOS 3 m68*-*-sunos3*
4681 Sun 3, running SunOS 4 m68*-*-sunos4*
4682 Sun 2, running SunOS 3 m68000-*-sunos3*
4683 Sun 2, running SunOS 4 m68000-*-sunos4*
4684 Motorola 680x0 running LynxOS m68*-*-lynxos*
4685 AT&T 3b1/Unix pc m68*-att-*
4686 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4687 decstation mips-dec-* mips-little-*
4688 riscos mips-*-riscos* mips-*-sysv*
4689 sonymips mips-sony-*
4690 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4692 *** Changes in GDB 6.1.1:
4694 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4696 The TUI (Text-mode User Interface) is now built as part of a default
4697 GDB configuration. It is enabled by either selecting the TUI with the
4698 command line option "-i=tui" or by running the separate "gdbtui"
4699 program. For more information on the TUI, see the manual "Debugging
4702 * Pending breakpoint support (also included in GDB 6.1)
4704 Support has been added to allow you to specify breakpoints in shared
4705 libraries that have not yet been loaded. If a breakpoint location
4706 cannot be found, and the "breakpoint pending" option is set to auto,
4707 GDB queries you if you wish to make the breakpoint pending on a future
4708 shared-library load. If and when GDB resolves the breakpoint symbol,
4709 the pending breakpoint is removed as one or more regular breakpoints
4712 Pending breakpoints are very useful for GCJ Java debugging.
4714 * Fixed ISO-C build problems
4716 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4717 non ISO-C code that stopped them being built using a more strict ISO-C
4718 compiler (e.g., IBM's C compiler).
4720 * Fixed build problem on IRIX 5
4722 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4723 wasn't able to compile compile on an IRIX 5 system.
4725 * Added execute permission to gdb/gdbserver/configure
4727 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4728 permission. This bug would cause configure to fail on a number of
4729 systems (Solaris, IRIX). Ref: server/519.
4731 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4733 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4734 has been updated to use constant array sizes.
4736 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4738 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4739 its generated DWARF Call Frame Info. This encoding was causing GDB to
4740 panic, that panic has been fixed. Ref: gdb/1628.
4742 * Fixed a problem when examining parameters in shared library code.
4744 When examining parameters in optimized shared library code generated
4745 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4746 not available''. GDB now correctly displays the variable's value.
4748 *** Changes in GDB 6.1:
4750 * Removed --with-mmalloc
4752 Support for the mmalloc memory manager has been removed, as it
4753 conflicted with the internal gdb byte cache.
4755 * Changes in AMD64 configurations
4757 The AMD64 target now includes the %cs and %ss registers. As a result
4758 the AMD64 remote protocol has changed; this affects the floating-point
4759 and SSE registers. If you rely on those registers for your debugging,
4760 you should upgrade gdbserver on the remote side.
4762 * Revised SPARC target
4764 The SPARC target has been completely revised, incorporating the
4765 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4766 support for LynxOS and SunOS 4 has been dropped. Calling functions
4767 from within GDB on operating systems with a non-executable stack
4768 (Solaris, OpenBSD) now works.
4772 GDB has a new C++ demangler which does a better job on the mangled
4773 names generated by current versions of g++. It also runs faster, so
4774 with this and other changes gdb should now start faster on large C++
4777 * DWARF 2 Location Expressions
4779 GDB support for location expressions has been extended to support function
4780 arguments and frame bases. Older versions of GDB could crash when they
4783 * C++ nested types and namespaces
4785 GDB's support for nested types and namespaces in C++ has been
4786 improved, especially if you use the DWARF 2 debugging format. (This
4787 is the default for recent versions of GCC on most platforms.)
4788 Specifically, if you have a class "Inner" defined within a class or
4789 namespace "Outer", then GDB realizes that the class's name is
4790 "Outer::Inner", not simply "Inner". This should greatly reduce the
4791 frequency of complaints about not finding RTTI symbols. In addition,
4792 if you are stopped at inside of a function defined within a namespace,
4793 GDB modifies its name lookup accordingly.
4795 * New native configurations
4797 NetBSD/amd64 x86_64-*-netbsd*
4798 OpenBSD/amd64 x86_64-*-openbsd*
4799 OpenBSD/alpha alpha*-*-openbsd*
4800 OpenBSD/sparc sparc-*-openbsd*
4801 OpenBSD/sparc64 sparc64-*-openbsd*
4803 * New debugging protocols
4805 M32R with SDI protocol m32r-*-elf*
4807 * "set prompt-escape-char" command deleted.
4809 The command "set prompt-escape-char" has been deleted. This command,
4810 and its very obscure effet on GDB's prompt, was never documented,
4811 tested, nor mentioned in the NEWS file.
4813 * OBSOLETE configurations and files
4815 Configurations that have been declared obsolete in this release have
4816 been commented out. Unless there is activity to revive these
4817 configurations, the next release of GDB will have their sources
4818 permanently REMOVED.
4820 Sun 3, running SunOS 3 m68*-*-sunos3*
4821 Sun 3, running SunOS 4 m68*-*-sunos4*
4822 Sun 2, running SunOS 3 m68000-*-sunos3*
4823 Sun 2, running SunOS 4 m68000-*-sunos4*
4824 Motorola 680x0 running LynxOS m68*-*-lynxos*
4825 AT&T 3b1/Unix pc m68*-att-*
4826 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4827 decstation mips-dec-* mips-little-*
4828 riscos mips-*-riscos* mips-*-sysv*
4829 sonymips mips-sony-*
4830 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4832 * REMOVED configurations and files
4834 SGI Irix-4.x mips-sgi-irix4 or iris4
4835 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4836 Z8000 simulator z8k-zilog-none or z8ksim
4837 Matsushita MN10200 w/simulator mn10200-*-*
4838 H8/500 simulator h8500-hitachi-hms or h8500hms
4839 HP/PA running BSD hppa*-*-bsd*
4840 HP/PA running OSF/1 hppa*-*-osf*
4841 HP/PA Pro target hppa*-*-pro*
4842 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4843 386BSD i[3456]86-*-bsd*
4844 Sequent family i[3456]86-sequent-sysv4*
4845 i[3456]86-sequent-sysv*
4846 i[3456]86-sequent-bsd*
4847 SPARC running LynxOS sparc-*-lynxos*
4848 SPARC running SunOS 4 sparc-*-sunos4*
4849 Tsqware Sparclet sparclet-*-*
4850 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4852 *** Changes in GDB 6.0:
4856 Support for debugging the Objective-C programming language has been
4857 integrated into GDB.
4859 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4861 DWARF 2's Call Frame Information makes available compiler generated
4862 information that more exactly describes the program's run-time stack.
4863 By using this information, GDB is able to provide more robust stack
4866 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4867 have been updated to use a new backtrace mechanism which includes
4868 DWARF 2 CFI support.
4872 GDB's remote protocol has been extended to include support for hosted
4873 file I/O (where the remote target uses GDB's file system). See GDB's
4874 remote protocol documentation for details.
4876 * All targets using the new architecture framework.
4878 All of GDB's targets have been updated to use the new internal
4879 architecture framework. The way is now open for future GDB releases
4880 to include cross-architecture native debugging support (i386 on amd64,
4883 * GNU/Linux's Thread Local Storage (TLS)
4885 GDB now includes support for for the GNU/Linux implementation of
4886 per-thread variables.
4888 * GNU/Linux's Native POSIX Thread Library (NPTL)
4890 GDB's thread code has been updated to work with either the new
4891 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4893 * Separate debug info.
4895 GDB, in conjunction with BINUTILS, now supports a mechanism for
4896 automatically loading debug information from a separate file. Instead
4897 of shipping full debug and non-debug versions of system libraries,
4898 system integrators can now instead ship just the stripped libraries
4899 and optional debug files.
4901 * DWARF 2 Location Expressions
4903 DWARF 2 Location Expressions allow the compiler to more completely
4904 describe the location of variables (even in optimized code) to the
4907 GDB now includes preliminary support for location expressions (support
4908 for DW_OP_piece is still missing).
4912 A number of long standing bugs that caused GDB to die while starting a
4913 Java application have been fixed. GDB's Java support is now
4914 considered "useable".
4916 * GNU/Linux support for fork, vfork, and exec.
4918 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4919 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4922 * GDB supports logging output to a file
4924 There are two new commands, "set logging" and "show logging", which can be
4925 used to capture GDB's output to a file.
4927 * The meaning of "detach" has changed for gdbserver
4929 The "detach" command will now resume the application, as documented. To
4930 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4933 * d10v, m68hc11 `regs' command deprecated
4935 The `info registers' command has been updated so that it displays the
4936 registers using a format identical to the old `regs' command.
4940 A new command, "maint set profile on/off", has been added. This command can
4941 be used to enable or disable profiling while running GDB, to profile a
4942 session or a set of commands. In addition there is a new configure switch,
4943 "--enable-profiling", which will cause GDB to be compiled with profiling
4944 data, for more informative profiling results.
4946 * Default MI syntax changed to "mi2".
4948 The default MI (machine interface) syntax, enabled by the command line
4949 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4950 "mi1", can be enabled by specifying the option "-i=mi1".
4952 Support for the original "mi0" syntax (included in GDB 5.0) has been
4955 Fix for gdb/192: removed extraneous space when displaying frame level.
4956 Fix for gdb/672: update changelist is now output in mi list format.
4957 Fix for gdb/702: a -var-assign that updates the value now shows up
4958 in a subsequent -var-update.
4960 * New native configurations.
4962 FreeBSD/amd64 x86_64-*-freebsd*
4964 * Multi-arched targets.
4966 HP/PA HPUX11 hppa*-*-hpux*
4967 Renesas M32R/D w/simulator m32r-*-elf*
4969 * OBSOLETE configurations and files
4971 Configurations that have been declared obsolete in this release have
4972 been commented out. Unless there is activity to revive these
4973 configurations, the next release of GDB will have their sources
4974 permanently REMOVED.
4976 Z8000 simulator z8k-zilog-none or z8ksim
4977 Matsushita MN10200 w/simulator mn10200-*-*
4978 H8/500 simulator h8500-hitachi-hms or h8500hms
4979 HP/PA running BSD hppa*-*-bsd*
4980 HP/PA running OSF/1 hppa*-*-osf*
4981 HP/PA Pro target hppa*-*-pro*
4982 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4983 Sequent family i[3456]86-sequent-sysv4*
4984 i[3456]86-sequent-sysv*
4985 i[3456]86-sequent-bsd*
4986 Tsqware Sparclet sparclet-*-*
4987 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4989 * REMOVED configurations and files
4992 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4993 IBM AIX PS/2 i[3456]86-*-aix
4994 i386 running Mach 3.0 i[3456]86-*-mach3*
4995 i386 running Mach i[3456]86-*-mach*
4996 i386 running OSF/1 i[3456]86-*osf1mk*
4997 HP/Apollo 68k Family m68*-apollo*-sysv*,
4999 m68*-hp-bsd*, m68*-hp-hpux*
5000 Argonaut Risc Chip (ARC) arc-*-*
5001 Mitsubishi D30V d30v-*-*
5002 Fujitsu FR30 fr30-*-elf*
5003 OS/9000 i[34]86-*-os9k
5004 I960 with MON960 i960-*-coff
5006 * MIPS $fp behavior changed
5008 The convenience variable $fp, for the MIPS, now consistently returns
5009 the address of the current frame's base. Previously, depending on the
5010 context, $fp could refer to either $sp or the current frame's base
5011 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5012 The GNU Source-Level Debugger''.
5014 *** Changes in GDB 5.3:
5016 * GNU/Linux shared library multi-threaded performance improved.
5018 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5019 `/proc', in preference to `ptrace' for memory reads. This may result
5020 in an improvement in the start-up time of multi-threaded, shared
5021 library applications when run under GDB. One GDB user writes: ``loads
5022 shared libs like mad''.
5024 * ``gdbserver'' now supports multi-threaded applications on some targets
5026 Support for debugging multi-threaded applications which use
5027 the GNU/Linux LinuxThreads package has been added for
5028 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5029 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5031 * GDB now supports C/C++ preprocessor macros.
5033 GDB now expands preprocessor macro invocations in C/C++ expressions,
5034 and provides various commands for showing macro definitions and how
5037 The new command `macro expand EXPRESSION' expands any macro
5038 invocations in expression, and shows the result.
5040 The new command `show macro MACRO-NAME' shows the definition of the
5041 macro named MACRO-NAME, and where it was defined.
5043 Most compilers don't include information about macros in the debugging
5044 information by default. In GCC 3.1, for example, you need to compile
5045 your program with the options `-gdwarf-2 -g3'. If the macro
5046 information is present in the executable, GDB will read it.
5048 * Multi-arched targets.
5050 DEC Alpha (partial) alpha*-*-*
5051 DEC VAX (partial) vax-*-*
5053 National Semiconductor NS32000 (partial) ns32k-*-*
5054 Motorola 68000 (partial) m68k-*-*
5055 Motorola MCORE mcore-*-*
5059 Fujitsu FRV architecture added by Red Hat frv*-*-*
5062 * New native configurations
5064 Alpha NetBSD alpha*-*-netbsd*
5065 SH NetBSD sh*-*-netbsdelf*
5066 MIPS NetBSD mips*-*-netbsd*
5067 UltraSPARC NetBSD sparc64-*-netbsd*
5069 * OBSOLETE configurations and files
5071 Configurations that have been declared obsolete in this release have
5072 been commented out. Unless there is activity to revive these
5073 configurations, the next release of GDB will have their sources
5074 permanently REMOVED.
5076 Mitsubishi D30V d30v-*-*
5077 OS/9000 i[34]86-*-os9k
5078 IBM AIX PS/2 i[3456]86-*-aix
5079 Fujitsu FR30 fr30-*-elf*
5080 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5081 Argonaut Risc Chip (ARC) arc-*-*
5082 i386 running Mach 3.0 i[3456]86-*-mach3*
5083 i386 running Mach i[3456]86-*-mach*
5084 i386 running OSF/1 i[3456]86-*osf1mk*
5085 HP/Apollo 68k Family m68*-apollo*-sysv*,
5087 m68*-hp-bsd*, m68*-hp-hpux*
5088 I960 with MON960 i960-*-coff
5090 * OBSOLETE languages
5092 CHILL, a Pascal like language used by telecommunications companies.
5094 * REMOVED configurations and files
5096 AMD 29k family via UDI a29k-amd-udi, udi29k
5097 A29K VxWorks a29k-*-vxworks
5098 AMD 29000 embedded, using EBMON a29k-none-none
5099 AMD 29000 embedded with COFF a29k-none-coff
5100 AMD 29000 embedded with a.out a29k-none-aout
5102 testsuite/gdb.hp/gdb.threads-hp/ directory
5104 * New command "set max-user-call-depth <nnn>"
5106 This command allows the user to limit the call depth of user-defined
5107 commands. The default is 1024.
5109 * Changes in FreeBSD/i386 native debugging.
5111 Support for the "generate-core-file" has been added.
5113 * New commands "dump", "append", and "restore".
5115 These commands allow data to be copied from target memory
5116 to a bfd-format or binary file (dump and append), and back
5117 from a file into memory (restore).
5119 * Improved "next/step" support on multi-processor Alpha Tru64.
5121 The previous single-step mechanism could cause unpredictable problems,
5122 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5123 of a software single-step mechanism prevents this.
5125 *** Changes in GDB 5.2.1:
5133 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5134 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5135 Fix, by Joel Brobecker imported from mainline.
5137 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5138 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5139 Fix, by Fred Fish, imported from mainline.
5141 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5142 Surprisingly enough, it works now.
5143 By Michal Ludvig, imported from mainline.
5145 i386 hardware watchpoint support:
5146 avoid misses on second run for some targets.
5147 By Pierre Muller, imported from mainline.
5149 *** Changes in GDB 5.2:
5151 * New command "set trust-readonly-sections on[off]".
5153 This command is a hint that tells gdb that read-only sections
5154 really are read-only (ie. that their contents will not change).
5155 In this mode, gdb will go to the object file rather than the
5156 target to read memory from read-only sections (such as ".text").
5157 This can be a significant performance improvement on some
5158 (notably embedded) targets.
5160 * New command "generate-core-file" (or "gcore").
5162 This new gdb command allows the user to drop a core file of the child
5163 process state at any time. So far it's been implemented only for
5164 GNU/Linux and Solaris, but should be relatively easily ported to other
5165 hosts. Argument is core file name (defaults to core.<pid>).
5167 * New command line option
5169 GDB now accepts --pid or -p followed by a process id.
5171 * Change in command line behavior -- corefiles vs. process ids.
5173 There is a subtle behavior in the way in which GDB handles
5174 command line arguments. The first non-flag argument is always
5175 a program to debug, but the second non-flag argument may either
5176 be a corefile or a process id. Previously, GDB would attempt to
5177 open the second argument as a corefile, and if that failed, would
5178 issue a superfluous error message and then attempt to attach it as
5179 a process. Now, if the second argument begins with a non-digit,
5180 it will be treated as a corefile. If it begins with a digit,
5181 GDB will attempt to attach it as a process, and if no such process
5182 is found, will then attempt to open it as a corefile.
5184 * Changes in ARM configurations.
5186 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5187 configuration is fully multi-arch.
5189 * New native configurations
5191 ARM NetBSD arm*-*-netbsd*
5192 x86 OpenBSD i[3456]86-*-openbsd*
5193 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5194 Sparc64 running FreeBSD sparc64-*-freebsd*
5198 Sanyo XStormy16 xstormy16-elf
5200 * OBSOLETE configurations and files
5202 Configurations that have been declared obsolete in this release have
5203 been commented out. Unless there is activity to revive these
5204 configurations, the next release of GDB will have their sources
5205 permanently REMOVED.
5207 AMD 29k family via UDI a29k-amd-udi, udi29k
5208 A29K VxWorks a29k-*-vxworks
5209 AMD 29000 embedded, using EBMON a29k-none-none
5210 AMD 29000 embedded with COFF a29k-none-coff
5211 AMD 29000 embedded with a.out a29k-none-aout
5213 testsuite/gdb.hp/gdb.threads-hp/ directory
5215 * REMOVED configurations and files
5217 TI TMS320C80 tic80-*-*
5219 PowerPC Solaris powerpcle-*-solaris*
5220 PowerPC Windows NT powerpcle-*-cygwin32
5221 PowerPC Netware powerpc-*-netware*
5222 Harris/CXUX m88k m88*-harris-cxux*
5223 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5224 ns32k-utek-sysv* ns32k-utek-*
5225 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5226 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5227 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5228 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5229 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5231 * Changes to command line processing
5233 The new `--args' feature can be used to specify command-line arguments
5234 for the inferior from gdb's command line.
5236 * Changes to key bindings
5238 There is a new `operate-and-get-next' function bound to `C-o'.
5240 *** Changes in GDB 5.1.1
5242 Fix compile problem on DJGPP.
5244 Fix a problem with floating-point registers on the i386 being
5247 Fix to stop GDB crashing on .debug_str debug info.
5249 Numerous documentation fixes.
5251 Numerous testsuite fixes.
5253 *** Changes in GDB 5.1:
5255 * New native configurations
5257 Alpha FreeBSD alpha*-*-freebsd*
5258 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5259 MIPS GNU/Linux mips*-*-linux*
5260 MIPS SGI Irix 6.x mips*-sgi-irix6*
5261 ia64 AIX ia64-*-aix*
5262 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5266 Motorola 68HC11 and 68HC12 m68hc11-elf
5268 UltraSparc running GNU/Linux sparc64-*-linux*
5270 * OBSOLETE configurations and files
5272 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5273 Harris/CXUX m88k m88*-harris-cxux*
5274 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5275 ns32k-utek-sysv* ns32k-utek-*
5276 TI TMS320C80 tic80-*-*
5278 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5279 PowerPC Solaris powerpcle-*-solaris*
5280 PowerPC Windows NT powerpcle-*-cygwin32
5281 PowerPC Netware powerpc-*-netware*
5282 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5283 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5284 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5285 Apple Macintosh (MPW) host N/A
5287 stuff.c (Program to stuff files into a specially prepared space in kdb)
5288 kdb-start.c (Main loop for the standalone kernel debugger)
5290 Configurations that have been declared obsolete in this release have
5291 been commented out. Unless there is activity to revive these
5292 configurations, the next release of GDB will have their sources
5293 permanently REMOVED.
5295 * REMOVED configurations and files
5297 Altos 3068 m68*-altos-*
5298 Convex c1-*-*, c2-*-*
5300 ARM RISCix arm-*-* (as host)
5304 * GDB has been converted to ISO C.
5306 GDB's source code has been converted to ISO C. In particular, the
5307 sources are fully protoized, and rely on standard headers being
5312 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5314 * The MI enabled by default.
5316 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5317 revised and enabled by default. Packages which use GDB as a debugging
5318 engine behind a UI or another front end are encouraged to switch to
5319 using the GDB/MI interface, instead of the old annotations interface
5320 which is now deprecated.
5322 * Support for debugging Pascal programs.
5324 GDB now includes support for debugging Pascal programs. The following
5325 main features are supported:
5327 - Pascal-specific data types such as sets;
5329 - automatic recognition of Pascal sources based on file-name
5332 - Pascal-style display of data types, variables, and functions;
5334 - a Pascal expression parser.
5336 However, some important features are not yet supported.
5338 - Pascal string operations are not supported at all;
5340 - there are some problems with boolean types;
5342 - Pascal type hexadecimal constants are not supported
5343 because they conflict with the internal variables format;
5345 - support for Pascal objects and classes is not full yet;
5347 - unlike Pascal, GDB is case-sensitive for symbol names.
5349 * Changes in completion.
5351 Commands such as `shell', `run' and `set args', which pass arguments
5352 to inferior programs, now complete on file names, similar to what
5353 users expect at the shell prompt.
5355 Commands which accept locations, such as `disassemble', `print',
5356 `breakpoint', `until', etc. now complete on filenames as well as
5357 program symbols. Thus, if you type "break foob TAB", and the source
5358 files linked into the programs include `foobar.c', that file name will
5359 be one of the candidates for completion. However, file names are not
5360 considered for completion after you typed a colon that delimits a file
5361 name from a name of a function in that file, as in "break foo.c:bar".
5363 `set demangle-style' completes on available demangling styles.
5365 * New platform-independent commands:
5367 It is now possible to define a post-hook for a command as well as a
5368 hook that runs before the command. For more details, see the
5369 documentation of `hookpost' in the GDB manual.
5371 * Changes in GNU/Linux native debugging.
5373 Support for debugging multi-threaded programs has been completely
5374 revised for all platforms except m68k and sparc. You can now debug as
5375 many threads as your system allows you to have.
5377 Attach/detach is supported for multi-threaded programs.
5379 Support for SSE registers was added for x86. This doesn't work for
5380 multi-threaded programs though.
5382 * Changes in MIPS configurations.
5384 Multi-arch support is enabled for all MIPS configurations.
5386 GDB can now be built as native debugger on SGI Irix 6.x systems for
5387 debugging n32 executables. (Debugging 64-bit executables is not yet
5390 * Unified support for hardware watchpoints in all x86 configurations.
5392 Most (if not all) native x86 configurations support hardware-assisted
5393 breakpoints and watchpoints in a unified manner. This support
5394 implements debug register sharing between watchpoints, which allows to
5395 put a virtually infinite number of watchpoints on the same address,
5396 and also supports watching regions up to 16 bytes with several debug
5399 The new maintenance command `maintenance show-debug-regs' toggles
5400 debugging print-outs in functions that insert, remove, and test
5401 watchpoints and hardware breakpoints.
5403 * Changes in the DJGPP native configuration.
5405 New command ``info dos sysinfo'' displays assorted information about
5406 the CPU, OS, memory, and DPMI server.
5408 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5409 display information about segment descriptors stored in GDT, LDT, and
5412 New commands ``info dos pde'' and ``info dos pte'' display entries
5413 from Page Directory and Page Tables (for now works with CWSDPMI only).
5414 New command ``info dos address-pte'' displays the Page Table entry for
5415 a given linear address.
5417 GDB can now pass command lines longer than 126 characters to the
5418 program being debugged (requires an update to the libdbg.a library
5419 which is part of the DJGPP development kit).
5421 DWARF2 debug info is now supported.
5423 It is now possible to `step' and `next' through calls to `longjmp'.
5425 * Changes in documentation.
5427 All GDB documentation was converted to GFDL, the GNU Free
5428 Documentation License.
5430 Tracepoints-related commands are now fully documented in the GDB
5433 TUI, the Text-mode User Interface, is now documented in the manual.
5435 Tracepoints-related commands are now fully documented in the GDB
5438 The "GDB Internals" manual now has an index. It also includes
5439 documentation of `ui_out' functions, GDB coding standards, x86
5440 hardware watchpoints, and memory region attributes.
5442 * GDB's version number moved to ``version.in''
5444 The Makefile variable VERSION has been replaced by the file
5445 ``version.in''. People creating GDB distributions should update the
5446 contents of this file.
5450 GUD support is now a standard part of the EMACS distribution.
5452 *** Changes in GDB 5.0:
5454 * Improved support for debugging FP programs on x86 targets
5456 Unified and much-improved support for debugging floating-point
5457 programs on all x86 targets. In particular, ``info float'' now
5458 displays the FP registers in the same format on all x86 targets, with
5459 greater level of detail.
5461 * Improvements and bugfixes in hardware-assisted watchpoints
5463 It is now possible to watch array elements, struct members, and
5464 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5465 on x86 targets no longer erroneously trigger when the address is
5468 * Improvements in the native DJGPP version of GDB
5470 The distribution now includes all the scripts and auxiliary files
5471 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5472 machines ``out of the box''.
5474 The DJGPP version can now debug programs that use signals. It is
5475 possible to catch signals that happened in the debuggee, deliver
5476 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5477 would kill the program being debugged.) Programs that hook hardware
5478 interrupts (keyboard, timer, etc.) can also be debugged.
5480 It is now possible to debug DJGPP programs that redirect their
5481 standard handles or switch them to raw (as opposed to cooked) mode, or
5482 even close them. The command ``run < foo > bar'' works as expected,
5483 and ``info terminal'' reports useful information about the debuggee's
5484 terminal, including raw/cooked mode, redirection, etc.
5486 The DJGPP version now uses termios functions for console I/O, which
5487 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5490 DOS-style file names with drive letters are now fully supported by
5493 It is now possible to debug DJGPP programs that switch their working
5494 directory. It is also possible to rerun the debuggee any number of
5495 times without restarting GDB; thus, you can use the same setup,
5496 breakpoints, etc. for many debugging sessions.
5498 * New native configurations
5500 ARM GNU/Linux arm*-*-linux*
5501 PowerPC GNU/Linux powerpc-*-linux*
5505 Motorola MCore mcore-*-*
5506 x86 VxWorks i[3456]86-*-vxworks*
5507 PowerPC VxWorks powerpc-*-vxworks*
5508 TI TMS320C80 tic80-*-*
5510 * OBSOLETE configurations
5512 Altos 3068 m68*-altos-*
5513 Convex c1-*-*, c2-*-*
5515 ARM RISCix arm-*-* (as host)
5518 Configurations that have been declared obsolete will be commented out,
5519 but the code will be left in place. If there is no activity to revive
5520 these configurations before the next release of GDB, the sources will
5521 be permanently REMOVED.
5523 * Gould support removed
5525 Support for the Gould PowerNode and NP1 has been removed.
5527 * New features for SVR4
5529 On SVR4 native platforms (such as Solaris), if you attach to a process
5530 without first loading a symbol file, GDB will now attempt to locate and
5531 load symbols from the running process's executable file.
5533 * Many C++ enhancements
5535 C++ support has been greatly improved. Overload resolution now works properly
5536 in almost all cases. RTTI support is on the way.
5538 * Remote targets can connect to a sub-program
5540 A popen(3) style serial-device has been added. This device starts a
5541 sub-process (such as a stand-alone simulator) and then communicates
5542 with that. The sub-program to run is specified using the syntax
5543 ``|<program> <args>'' vis:
5545 (gdb) set remotedebug 1
5546 (gdb) target extended-remote |mn10300-elf-sim program-args
5548 * MIPS 64 remote protocol
5550 A long standing bug in the mips64 remote protocol where by GDB
5551 expected certain 32 bit registers (ex SR) to be transfered as 32
5552 instead of 64 bits has been fixed.
5554 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5555 added to provide backward compatibility with older versions of GDB.
5557 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5559 The command ``set remotebinarydownload'' command has been replaced by
5560 ``set remote X-packet''. Other commands in ``set remote'' family
5561 include ``set remote P-packet''.
5563 * Breakpoint commands accept ranges.
5565 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5566 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5567 ``tracepoint passcount'' also accepts a range of tracepoints.
5569 * ``apropos'' command added.
5571 The ``apropos'' command searches through command names and
5572 documentation strings, printing out matches, making it much easier to
5573 try to find a command that does what you are looking for.
5577 A new machine oriented interface (MI) has been added to GDB. This
5578 interface is designed for debug environments running GDB as a separate
5579 process. This is part of the long term libGDB project. See the
5580 "GDB/MI" chapter of the GDB manual for further information. It can be
5581 enabled by configuring with:
5583 .../configure --enable-gdbmi
5585 *** Changes in GDB-4.18:
5587 * New native configurations
5589 HP-UX 10.20 hppa*-*-hpux10.20
5590 HP-UX 11.x hppa*-*-hpux11.0*
5591 M68K GNU/Linux m68*-*-linux*
5595 Fujitsu FR30 fr30-*-elf*
5596 Intel StrongARM strongarm-*-*
5597 Mitsubishi D30V d30v-*-*
5599 * OBSOLETE configurations
5601 Gould PowerNode, NP1 np1-*-*, pn-*-*
5603 Configurations that have been declared obsolete will be commented out,
5604 but the code will be left in place. If there is no activity to revive
5605 these configurations before the next release of GDB, the sources will
5606 be permanently REMOVED.
5610 As a compatibility experiment, GDB's source files buildsym.h and
5611 buildsym.c have been converted to pure standard C, no longer
5612 containing any K&R compatibility code. We believe that all systems in
5613 use today either come with a standard C compiler, or have a GCC port
5614 available. If this is not true, please report the affected
5615 configuration to bug-gdb@gnu.org immediately. See the README file for
5616 information about getting a standard C compiler if you don't have one
5621 GDB now uses readline 2.2.
5623 * set extension-language
5625 You can now control the mapping between filename extensions and source
5626 languages by using the `set extension-language' command. For instance,
5627 you can ask GDB to treat .c files as C++ by saying
5628 set extension-language .c c++
5629 The command `info extensions' lists all of the recognized extensions
5630 and their associated languages.
5632 * Setting processor type for PowerPC and RS/6000
5634 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5635 you can use the `set processor' command to specify what variant of the
5636 PowerPC family you are debugging. The command
5640 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5641 following PowerPC and RS6000 variants:
5643 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5644 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5646 403GC IBM PowerPC 403GC
5647 505 Motorola PowerPC 505
5648 860 Motorola PowerPC 860 or 850
5649 601 Motorola PowerPC 601
5650 602 Motorola PowerPC 602
5651 603 Motorola/IBM PowerPC 603 or 603e
5652 604 Motorola PowerPC 604 or 604e
5653 750 Motorola/IBM PowerPC 750 or 750
5655 At the moment, this command just tells GDB what to name the
5656 special-purpose processor registers. Since almost all the affected
5657 registers are inaccessible to user-level programs, this command is
5658 only useful for remote debugging in its present form.
5662 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5663 more extensive support for HP-UX. Added features include shared
5664 library support, kernel threads and hardware watchpoints for 11.00,
5665 support for HP's ANSI C and C++ compilers, and a compatibility mode
5666 for xdb and dbx commands.
5670 HP's donation includes the new concept of catchpoints, which is a
5671 generalization of the old catch command. On HP-UX, it is now possible
5672 to catch exec, fork, and vfork, as well as library loading.
5674 This means that the existing catch command has changed; its first
5675 argument now specifies the type of catch to be set up. See the
5676 output of "help catch" for a list of catchpoint types.
5678 * Debugging across forks
5680 On HP-UX, you can choose which process to debug when a fork() happens
5685 HP has donated a curses-based terminal user interface (TUI). To get
5686 it, build with --enable-tui. Although this can be enabled for any
5687 configuration, at present it only works for native HP debugging.
5689 * GDB remote protocol additions
5691 A new protocol packet 'X' that writes binary data is now available.
5692 Default behavior is to try 'X', then drop back to 'M' if the stub
5693 fails to respond. The settable variable `remotebinarydownload'
5694 allows explicit control over the use of 'X'.
5696 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5697 full 64-bit address. The command
5699 set remoteaddresssize 32
5701 can be used to revert to the old behaviour. For existing remote stubs
5702 the change should not be noticed, as the additional address information
5705 In order to assist in debugging stubs, you may use the maintenance
5706 command `packet' to send any text string to the stub. For instance,
5708 maint packet heythere
5710 sends the packet "$heythere#<checksum>". Note that it is very easy to
5711 disrupt a debugging session by sending the wrong packet at the wrong
5714 The compare-sections command allows you to compare section data on the
5715 target to what is in the executable file without uploading or
5716 downloading, by comparing CRC checksums.
5718 * Tracing can collect general expressions
5720 You may now collect general expressions at tracepoints. This requires
5721 further additions to the target-side stub; see tracepoint.c and
5722 doc/agentexpr.texi for further details.
5724 * mask-address variable for Mips
5726 For Mips targets, you may control the zeroing of the upper 32 bits of
5727 a 64-bit address by entering `set mask-address on'. This is mainly
5728 of interest to users of embedded R4xxx and R5xxx processors.
5730 * Higher serial baud rates
5732 GDB's serial code now allows you to specify baud rates 57600, 115200,
5733 230400, and 460800 baud. (Note that your host system may not be able
5734 to achieve all of these rates.)
5738 The i960 configuration now includes an initial implementation of a
5739 builtin simulator, contributed by Jim Wilson.
5742 *** Changes in GDB-4.17:
5744 * New native configurations
5746 Alpha GNU/Linux alpha*-*-linux*
5747 Unixware 2.x i[3456]86-unixware2*
5748 Irix 6.x mips*-sgi-irix6*
5749 PowerPC GNU/Linux powerpc-*-linux*
5750 PowerPC Solaris powerpcle-*-solaris*
5751 Sparc GNU/Linux sparc-*-linux*
5752 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5756 Argonaut Risc Chip (ARC) arc-*-*
5757 Hitachi H8/300S h8300*-*-*
5758 Matsushita MN10200 w/simulator mn10200-*-*
5759 Matsushita MN10300 w/simulator mn10300-*-*
5760 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5761 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5762 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5763 Mitsubishi D10V w/simulator d10v-*-*
5764 Mitsubishi M32R/D w/simulator m32r-*-elf*
5765 Tsqware Sparclet sparclet-*-*
5766 NEC V850 w/simulator v850-*-*
5768 * New debugging protocols
5770 ARM with RDI protocol arm*-*-*
5771 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5772 DDB and LSI variants of PMON protocol mips*-*-*
5773 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5774 PowerPC with SDS protocol powerpc{,le}-*-eabi
5775 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5779 All configurations can now understand and use the DWARF 2 debugging
5780 format. The choice is automatic, if the symbol file contains DWARF 2
5785 GDB now includes basic Java language support. This support is
5786 only useful with Java compilers that produce native machine code.
5788 * solib-absolute-prefix and solib-search-path
5790 For SunOS and SVR4 shared libraries, you may now set the prefix for
5791 loading absolute shared library symbol files, and the search path for
5792 locating non-absolute shared library symbol files.
5794 * Live range splitting
5796 GDB can now effectively debug code for which GCC has performed live
5797 range splitting as part of its optimization. See gdb/doc/LRS for
5798 more details on the expected format of the stabs information.
5802 GDB's support for the GNU Hurd, including thread debugging, has been
5803 updated to work with current versions of the Hurd.
5807 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5808 instruction set. ARM GDB automatically detects when Thumb
5809 instructions are in use, and adjusts disassembly and backtracing
5814 GDB's MIPS target configurations now handle the MIP16 16-bit
5819 GDB now includes support for overlays; if an executable has been
5820 linked such that multiple sections are based at the same address, GDB
5821 will decide which section to use for symbolic info. You can choose to
5822 control the decision manually, using overlay commands, or implement
5823 additional target-side support and use "overlay load-target" to bring
5824 in the overlay mapping. Do "help overlay" for more detail.
5828 The command "info symbol <address>" displays information about
5829 the symbol at the specified address.
5833 The standard remote protocol now includes an extension that allows
5834 asynchronous collection and display of trace data. This requires
5835 extensive support in the target-side debugging stub. Tracing mode
5836 includes a new interaction mode in GDB and new commands: see the
5837 file tracepoint.c for more details.
5841 Configurations for embedded MIPS now include a simulator contributed
5842 by Cygnus Solutions. The simulator supports the instruction sets
5843 of most MIPS variants.
5847 Sparc configurations may now include the ERC32 simulator contributed
5848 by the European Space Agency. The simulator is not built into
5849 Sparc targets by default; configure with --enable-sim to include it.
5853 For target configurations that may include multiple variants of a
5854 basic architecture (such as MIPS and SH), you may now set the
5855 architecture explicitly. "set arch" sets, "info arch" lists
5856 the possible architectures.
5858 *** Changes in GDB-4.16:
5860 * New native configurations
5862 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5863 M68K NetBSD m68k-*-netbsd*
5864 PowerPC AIX 4.x powerpc-*-aix*
5865 PowerPC MacOS powerpc-*-macos*
5866 PowerPC Windows NT powerpcle-*-cygwin32
5867 RS/6000 AIX 4.x rs6000-*-aix4*
5871 ARM with RDP protocol arm-*-*
5872 I960 with MON960 i960-*-coff
5873 MIPS VxWorks mips*-*-vxworks*
5874 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5875 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5877 Matra Sparclet sparclet-*-*
5881 The powerpc-eabi configuration now includes the PSIM simulator,
5882 contributed by Andrew Cagney, with assistance from Mike Meissner.
5883 PSIM is a very elaborate model of the PowerPC, including not only
5884 basic instruction set execution, but also details of execution unit
5885 performance and I/O hardware. See sim/ppc/README for more details.
5889 GDB now works with Solaris 2.5.
5891 * Windows 95/NT native
5893 GDB will now work as a native debugger on Windows 95 and Windows NT.
5894 To build it from source, you must use the "gnu-win32" environment,
5895 which uses a DLL to emulate enough of Unix to run the GNU tools.
5896 Further information, binaries, and sources are available at
5897 ftp.cygnus.com, under pub/gnu-win32.
5899 * dont-repeat command
5901 If a user-defined command includes the command `dont-repeat', then the
5902 command will not be repeated if the user just types return. This is
5903 useful if the command is time-consuming to run, so that accidental
5904 extra keystrokes don't run the same command many times.
5906 * Send break instead of ^C
5908 The standard remote protocol now includes an option to send a break
5909 rather than a ^C to the target in order to interrupt it. By default,
5910 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5912 * Remote protocol timeout
5914 The standard remote protocol includes a new variable `remotetimeout'
5915 that allows you to set the number of seconds before GDB gives up trying
5916 to read from the target. The default value is 2.
5918 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5920 By default GDB will automatically keep track of objects as they are
5921 loaded and unloaded by the dynamic linker. By using the command `set
5922 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5923 when shared library events occur, thus allowing you to set breakpoints
5924 in shared libraries which are explicitly loaded by the inferior.
5926 Note this feature does not work on hpux8. On hpux9 you must link
5927 /usr/lib/end.o into your program. This feature should work
5928 automatically on hpux10.
5930 * Irix 5.x hardware watchpoint support
5932 Irix 5 configurations now support the use of hardware watchpoints.
5934 * Mips protocol "SYN garbage limit"
5936 When debugging a Mips target using the `target mips' protocol, you
5937 may set the number of characters that GDB will ignore by setting
5938 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5939 every character. The default value is 1050.
5941 * Recording and replaying remote debug sessions
5943 If you set `remotelogfile' to the name of a file, gdb will write to it
5944 a recording of a remote debug session. This recording may then be
5945 replayed back to gdb using "gdbreplay". See gdbserver/README for
5946 details. This is useful when you have a problem with GDB while doing
5947 remote debugging; you can make a recording of the session and send it
5948 to someone else, who can then recreate the problem.
5950 * Speedups for remote debugging
5952 GDB includes speedups for downloading and stepping MIPS systems using
5953 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5954 and more efficient S-record downloading.
5956 * Memory use reductions and statistics collection
5958 GDB now uses less memory and reports statistics about memory usage.
5959 Try the `maint print statistics' command, for example.
5961 *** Changes in GDB-4.15:
5963 * Psymtabs for XCOFF
5965 The symbol reader for AIX GDB now uses partial symbol tables. This
5966 can greatly improve startup time, especially for large executables.
5968 * Remote targets use caching
5970 Remote targets now use a data cache to speed up communication with the
5971 remote side. The data cache could lead to incorrect results because
5972 it doesn't know about volatile variables, thus making it impossible to
5973 debug targets which use memory mapped I/O devices. `set remotecache
5974 off' turns the the data cache off.
5976 * Remote targets may have threads
5978 The standard remote protocol now includes support for multiple threads
5979 in the target system, using new protocol commands 'H' and 'T'. See
5980 gdb/remote.c for details.
5984 If GDB is configured with `--enable-netrom', then it will include
5985 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5986 acts as though it is a bank of ROM on the target board, but you can
5987 write into it over the network. GDB's support consists only of
5988 support for fast loading into the emulated ROM; to debug, you must use
5989 another protocol, such as standard remote protocol. The usual
5990 sequence is something like
5992 target nrom <netrom-hostname>
5994 target remote <netrom-hostname>:1235
5998 GDB now includes support for the Apple Macintosh, as a host only. It
5999 may be run as either an MPW tool or as a standalone application, and
6000 it can debug through the serial port. All the usual GDB commands are
6001 available, but to the target command, you must supply "serial" as the
6002 device type instead of "/dev/ttyXX". See mpw-README in the main
6003 directory for more information on how to build. The MPW configuration
6004 scripts */mpw-config.in support only a few targets, and only the
6005 mips-idt-ecoff target has been tested.
6009 GDB configuration now uses autoconf. This is not user-visible,
6010 but does simplify configuration and building.
6014 GDB now supports hpux10.
6016 *** Changes in GDB-4.14:
6018 * New native configurations
6020 x86 FreeBSD i[345]86-*-freebsd
6021 x86 NetBSD i[345]86-*-netbsd
6022 NS32k NetBSD ns32k-*-netbsd
6023 Sparc NetBSD sparc-*-netbsd
6027 A29K VxWorks a29k-*-vxworks
6028 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6029 CPU32 EST-300 emulator m68*-*-est*
6030 PowerPC ELF powerpc-*-elf
6033 * Alpha OSF/1 support for procfs
6035 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6036 possible to attach to running processes. As the mounting of the /proc
6037 filesystem is optional on the Alpha, GDB automatically determines
6038 the availability of /proc during startup. This can lead to problems
6039 if /proc is unmounted after GDB has been started.
6041 * Arguments to user-defined commands
6043 User commands may accept up to 10 arguments separated by whitespace.
6044 Arguments are accessed within the user command via $arg0..$arg9. A
6047 print $arg0 + $arg1 + $arg2
6049 To execute the command use:
6052 Defines the command "adder" which prints the sum of its three arguments.
6053 Note the arguments are text substitutions, so they may reference variables,
6054 use complex expressions, or even perform inferior function calls.
6056 * New `if' and `while' commands
6058 This makes it possible to write more sophisticated user-defined
6059 commands. Both commands take a single argument, which is the
6060 expression to evaluate, and must be followed by the commands to
6061 execute, one per line, if the expression is nonzero, the list being
6062 terminated by the word `end'. The `if' command list may include an
6063 `else' word, which causes the following commands to be executed only
6064 if the expression is zero.
6066 * Fortran source language mode
6068 GDB now includes partial support for Fortran 77. It will recognize
6069 Fortran programs and can evaluate a subset of Fortran expressions, but
6070 variables and functions may not be handled correctly. GDB will work
6071 with G77, but does not yet know much about symbols emitted by other
6074 * Better HPUX support
6076 Most debugging facilities now work on dynamic executables for HPPAs
6077 running hpux9 or later. You can attach to running dynamically linked
6078 processes, but by default the dynamic libraries will be read-only, so
6079 for instance you won't be able to put breakpoints in them. To change
6080 that behavior do the following before running the program:
6086 This will cause the libraries to be mapped private and read-write.
6087 To revert to the normal behavior, do this:
6093 You cannot set breakpoints or examine data in the library until after
6094 the library is loaded if the function/data symbols do not have
6097 GDB can now also read debug symbols produced by the HP C compiler on
6098 HPPAs (sorry, no C++, Fortran or 68k support).
6100 * Target byte order now dynamically selectable
6102 You can choose which byte order to use with a target system, via the
6103 commands "set endian big" and "set endian little", and you can see the
6104 current setting by using "show endian". You can also give the command
6105 "set endian auto", in which case GDB will use the byte order
6106 associated with the executable. Currently, only embedded MIPS
6107 configurations support dynamic selection of target byte order.
6109 * New DOS host serial code
6111 This version uses DPMI interrupts to handle buffered I/O, so you
6112 no longer need to run asynctsr when debugging boards connected to
6115 *** Changes in GDB-4.13:
6117 * New "complete" command
6119 This lists all the possible completions for the rest of the line, if it
6120 were to be given as a command itself. This is intended for use by emacs.
6122 * Trailing space optional in prompt
6124 "set prompt" no longer adds a space for you after the prompt you set. This
6125 allows you to set a prompt which ends in a space or one that does not.
6127 * Breakpoint hit counts
6129 "info break" now displays a count of the number of times the breakpoint
6130 has been hit. This is especially useful in conjunction with "ignore"; you
6131 can ignore a large number of breakpoint hits, look at the breakpoint info
6132 to see how many times the breakpoint was hit, then run again, ignoring one
6133 less than that number, and this will get you quickly to the last hit of
6136 * Ability to stop printing at NULL character
6138 "set print null-stop" will cause GDB to stop printing the characters of
6139 an array when the first NULL is encountered. This is useful when large
6140 arrays actually contain only short strings.
6142 * Shared library breakpoints
6144 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6145 breakpoints in shared libraries before the executable is run.
6147 * Hardware watchpoints
6149 There is a new hardware breakpoint for the watch command for sparclite
6150 targets. See gdb/sparclite/hw_breakpoint.note.
6152 Hardware watchpoints are also now supported under GNU/Linux.
6156 Annotations have been added. These are for use with graphical interfaces,
6157 and are still experimental. Currently only gdba.el uses these.
6159 * Improved Irix 5 support
6161 GDB now works properly with Irix 5.2.
6163 * Improved HPPA support
6165 GDB now works properly with the latest GCC and GAS.
6167 * New native configurations
6169 Sequent PTX4 i[34]86-sequent-ptx4
6170 HPPA running OSF/1 hppa*-*-osf*
6171 Atari TT running SVR4 m68*-*-sysv4*
6172 RS/6000 LynxOS rs6000-*-lynxos*
6176 OS/9000 i[34]86-*-os9k
6177 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6180 * Hitachi SH7000 and E7000-PC ICE support
6182 There is now support for communicating with the Hitachi E7000-PC ICE.
6183 This is available automatically when GDB is configured for the SH.
6187 As usual, a variety of small fixes and improvements, both generic
6188 and configuration-specific. See the ChangeLog for more detail.
6190 *** Changes in GDB-4.12:
6192 * Irix 5 is now supported
6196 GDB-4.12 on the HPPA has a number of changes which make it unable
6197 to debug the output from the currently released versions of GCC and
6198 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6199 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6200 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6203 *** Changes in GDB-4.11:
6205 * User visible changes:
6209 The "set remotedebug" option is now consistent between the mips remote
6210 target, remote targets using the gdb-specific protocol, UDI (AMD's
6211 debug protocol for the 29k) and the 88k bug monitor. It is now an
6212 integer specifying a debug level (normally 0 or 1, but 2 means more
6213 debugging info for the mips target).
6215 * DEC Alpha native support
6217 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6218 debug info, but GDB works fairly well with the DEC compiler and should
6219 work with a future GCC release. See the README file for a few
6220 Alpha-specific notes.
6222 * Preliminary thread implementation
6224 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6226 * LynxOS native and target support for 386
6228 This release has been hosted on LynxOS 2.2, and also can be configured
6229 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6232 * Improvements in C++ mangling/demangling.
6234 This release has much better g++ debugging, specifically in name
6235 mangling/demangling, virtual function calls, print virtual table,
6236 call methods, ...etc.
6238 *** Changes in GDB-4.10:
6240 * User visible changes:
6242 Remote debugging using the GDB-specific (`target remote') protocol now
6243 supports the `load' command. This is only useful if you have some
6244 other way of getting the stub to the target system, and you can put it
6245 somewhere in memory where it won't get clobbered by the download.
6247 Filename completion now works.
6249 When run under emacs mode, the "info line" command now causes the
6250 arrow to point to the line specified. Also, "info line" prints
6251 addresses in symbolic form (as well as hex).
6253 All vxworks based targets now support a user settable option, called
6254 vxworks-timeout. This option represents the number of seconds gdb
6255 should wait for responses to rpc's. You might want to use this if
6256 your vxworks target is, perhaps, a slow software simulator or happens
6257 to be on the far side of a thin network line.
6261 This release contains support for using a DEC alpha as a GDB host for
6262 cross debugging. Native alpha debugging is not supported yet.
6265 *** Changes in GDB-4.9:
6269 This is the first GDB release which is accompanied by a matching testsuite.
6270 The testsuite requires installation of dejagnu, which should be available
6271 via ftp from most sites that carry GNU software.
6275 'Cfront' style demangling has had its name changed to 'ARM' style, to
6276 emphasize that it was written from the specifications in the C++ Annotated
6277 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6278 disclaimers, it still generated too much confusion with users attempting to
6279 use gdb with AT&T cfront.
6283 GDB now uses a standard remote interface to a simulator library.
6284 So far, the library contains simulators for the Zilog Z8001/2, the
6285 Hitachi H8/300, H8/500 and Super-H.
6287 * New targets supported
6289 H8/300 simulator h8300-hitachi-hms or h8300hms
6290 H8/500 simulator h8500-hitachi-hms or h8500hms
6291 SH simulator sh-hitachi-hms or sh
6292 Z8000 simulator z8k-zilog-none or z8ksim
6293 IDT MIPS board over serial line mips-idt-ecoff
6295 Cross-debugging to GO32 targets is supported. It requires a custom
6296 version of the i386-stub.c module which is integrated with the
6297 GO32 memory extender.
6299 * New remote protocols
6301 MIPS remote debugging protocol.
6303 * New source languages supported
6305 This version includes preliminary support for Chill, a Pascal like language
6306 used by telecommunications companies. Chill support is also being integrated
6307 into the GNU compiler, but we don't know when it will be publically available.
6310 *** Changes in GDB-4.8:
6312 * HP Precision Architecture supported
6314 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6315 version of this support was available as a set of patches from the
6316 University of Utah. GDB does not support debugging of programs
6317 compiled with the HP compiler, because HP will not document their file
6318 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6319 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6321 Many problems in the preliminary version have been fixed.
6323 * Faster and better demangling
6325 We have improved template demangling and fixed numerous bugs in the GNU style
6326 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6327 character types (wchar_t) are now supported. Demangling of each symbol is now
6328 only done once, and is cached when the symbol table for a file is read in.
6329 This results in a small increase in memory usage for C programs, a moderate
6330 increase in memory usage for C++ programs, and a fantastic speedup in
6333 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6334 from the specifications in the Annotated Reference Manual, which AT&T's
6335 compiler does not actually implement.
6337 * G++ multiple inheritance compiler problem
6339 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6340 inheritance lattices was reworked to properly discover ambiguities. We
6341 recently found an example which causes this new algorithm to fail in a
6342 very subtle way, producing bad debug information for those classes.
6343 The file 'gcc.patch' (in this directory) can be applied to gcc to
6344 circumvent the problem. A future GCC release will contain a complete
6347 The previous G++ debug info problem (mentioned below for the gdb-4.7
6348 release) is fixed in gcc version 2.3.2.
6350 * Improved configure script
6352 The `configure' script will now attempt to guess your system type if
6353 you don't supply a host system type. The old scheme of supplying a
6354 host system triplet is preferable over using this. All the magic is
6355 done in the new `config.guess' script. Examine it for details.
6357 We have also brought our configure script much more in line with the FSF's
6358 version. It now supports the --with-xxx options. In particular,
6359 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6360 The resulting GDB will not be able to read arbitrary object file formats --
6361 only the format ``expected'' to be used on the configured target system.
6362 We hope to make this the default in a future release.
6364 * Documentation improvements
6366 There's new internal documentation on how to modify GDB, and how to
6367 produce clean changes to the code. We implore people to read it
6368 before submitting changes.
6370 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6371 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6372 `info' files are also provided. To build `info' files from scratch,
6373 you will need the latest `makeinfo' release, which will be available in
6374 a future texinfo-X.Y release.
6376 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6377 We're not sure exactly which versions have this problem, but it has
6378 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6379 or better. If that isn't possible, there is a patch in
6380 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6381 around this problem.
6385 GDB now supports array constants that can be used in expressions typed in by
6386 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6387 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6390 The new directory `gdb/sparclite' contains a program that demonstrates
6391 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6393 * New native hosts supported
6395 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6396 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6398 * New targets supported
6400 AMD 29k family via UDI a29k-amd-udi or udi29k
6402 * New file formats supported
6404 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6405 HPUX core files, and SCO 3.2v2 core files.
6409 Attaching to processes now works again; thanks for the many bug reports.
6411 We have also stomped on a bunch of core dumps caused by
6412 printf_filtered("%s") problems.
6414 We eliminated a copyright problem on the rpc and ptrace header files
6415 for VxWorks, which was discovered at the last minute during the 4.7
6416 release. You should now be able to build a VxWorks GDB.
6418 You can now interrupt gdb while an attached process is running. This
6419 will cause the attached process to stop, and give control back to GDB.
6421 We fixed problems caused by using too many file descriptors
6422 for reading symbols from object files and libraries. This was
6423 especially a problem for programs that used many (~100) shared
6426 The `step' command now only enters a subroutine if there is line number
6427 information for the subroutine. Otherwise it acts like the `next'
6428 command. Previously, `step' would enter subroutines if there was
6429 any debugging information about the routine. This avoids problems
6430 when using `cc -g1' on MIPS machines.
6432 * Internal improvements
6434 GDB's internal interfaces have been improved to make it easier to support
6435 debugging of multiple languages in the future.
6437 GDB now uses a common structure for symbol information internally.
6438 Minimal symbols (derived from linkage symbols in object files), partial
6439 symbols (from a quick scan of debug information), and full symbols
6440 contain a common subset of information, making it easier to write
6441 shared code that handles any of them.
6443 * New command line options
6445 We now accept --silent as an alias for --quiet.
6449 The memory-mapped-malloc library is now licensed under the GNU Library
6450 General Public License.
6452 *** Changes in GDB-4.7:
6454 * Host/native/target split
6456 GDB has had some major internal surgery to untangle the support for
6457 hosts and remote targets. Now, when you configure GDB for a remote
6458 target, it will no longer load in all of the support for debugging
6459 local programs on the host. When fully completed and tested, this will
6460 ensure that arbitrary host/target combinations are possible.
6462 The primary conceptual shift is to separate the non-portable code in
6463 GDB into three categories. Host specific code is required any time GDB
6464 is compiled on that host, regardless of the target. Target specific
6465 code relates to the peculiarities of the target, but can be compiled on
6466 any host. Native specific code is everything else: it can only be
6467 built when the host and target are the same system. Child process
6468 handling and core file support are two common `native' examples.
6470 GDB's use of /proc for controlling Unix child processes is now cleaner.
6471 It has been split out into a single module under the `target_ops' vector,
6472 plus two native-dependent functions for each system that uses /proc.
6474 * New hosts supported
6476 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6477 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6478 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6480 * New targets supported
6482 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6483 68030 and CPU32 m68030-*-*, m68332-*-*
6485 * New native hosts supported
6487 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6488 (386bsd is not well tested yet)
6489 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6491 * New file formats supported
6493 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6494 supports reading of `a.out.adobe' object files, which are an a.out
6495 format extended with minimal information about multiple sections.
6499 `show copying' is the same as the old `info copying'.
6500 `show warranty' is the same as `info warrantee'.
6501 These were renamed for consistency. The old commands continue to work.
6503 `info handle' is a new alias for `info signals'.
6505 You can now define pre-command hooks, which attach arbitrary command
6506 scripts to any command. The commands in the hook will be executed
6507 prior to the user's command. You can also create a hook which will be
6508 executed whenever the program stops. See gdb.texinfo.
6512 We now deal with Cfront style name mangling, and can even extract type
6513 info from mangled symbols. GDB can automatically figure out which
6514 symbol mangling style your C++ compiler uses.
6516 Calling of methods and virtual functions has been improved as well.
6520 The crash that occured when debugging Sun Ansi-C compiled binaries is
6521 fixed. This was due to mishandling of the extra N_SO stabs output
6524 We also finally got Ultrix 4.2 running in house, and fixed core file
6525 support, with help from a dozen people on the net.
6527 John M. Farrell discovered that the reason that single-stepping was so
6528 slow on all of the Mips based platforms (primarily SGI and DEC) was
6529 that we were trying to demangle and lookup a symbol used for internal
6530 purposes on every instruction that was being stepped through. Changing
6531 the name of that symbol so that it couldn't be mistaken for a C++
6532 mangled symbol sped things up a great deal.
6534 Rich Pixley sped up symbol lookups in general by getting much smarter
6535 about when C++ symbol mangling is necessary. This should make symbol
6536 completion (TAB on the command line) much faster. It's not as fast as
6537 we'd like, but it's significantly faster than gdb-4.6.
6541 A new user controllable variable 'call_scratch_address' can
6542 specify the location of a scratch area to be used when GDB
6543 calls a function in the target. This is necessary because the
6544 usual method of putting the scratch area on the stack does not work
6545 in systems that have separate instruction and data spaces.
6547 We integrated changes to support the 29k UDI (Universal Debugger
6548 Interface), but discovered at the last minute that we didn't have all
6549 of the appropriate copyright paperwork. We are working with AMD to
6550 resolve this, and hope to have it available soon.
6554 We have sped up the remote serial line protocol, especially for targets
6555 with lots of registers. It now supports a new `expedited status' ('T')
6556 message which can be used in place of the existing 'S' status message.
6557 This allows the remote stub to send only the registers that GDB
6558 needs to make a quick decision about single-stepping or conditional
6559 breakpoints, eliminating the need to fetch the entire register set for
6560 each instruction being stepped through.
6562 The GDB remote serial protocol now implements a write-through cache for
6563 registers, only re-reading the registers if the target has run.
6565 There is also a new remote serial stub for SPARC processors. You can
6566 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6567 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6568 processor with a serial port.
6572 Configure.in files have become much easier to read and modify. A new
6573 `table driven' format makes it more obvious what configurations are
6574 supported, and what files each one uses.
6578 There is a new opcodes library which will eventually contain all of the
6579 disassembly routines and opcode tables. At present, it only contains
6580 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6581 disassembler (binutils/objdump) to share these routines.
6583 The libiberty library is now copylefted under the GNU Library General
6584 Public License. This allows more liberal use, and was done so libg++
6585 can use it. This makes no difference to GDB, since the Library License
6586 grants all the rights from the General Public License.
6590 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6591 reference to the stabs symbol info used by the debugger. It is (as far
6592 as we know) the only published document on this fascinating topic. We
6593 encourage you to read it, compare it to the stabs information on your
6594 system, and send improvements on the document in general (to
6595 bug-gdb@prep.ai.mit.edu).
6597 And, of course, many bugs have been fixed.
6600 *** Changes in GDB-4.6:
6602 * Better support for C++ function names
6604 GDB now accepts as input the "demangled form" of C++ overloaded function
6605 names and member function names, and can do command completion on such names
6606 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6607 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6608 Make use of command completion, it is your friend.
6610 GDB also now accepts a variety of C++ mangled symbol formats. They are
6611 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6612 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6613 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6614 for the list of formats.
6616 * G++ symbol mangling problem
6618 Recent versions of gcc have a bug in how they emit debugging information for
6619 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6620 directory) can be applied to gcc to fix the problem. Alternatively, if you
6621 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6622 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6623 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6626 * New 'maintenance' command
6628 All of the commands related to hacking GDB internals have been moved out of
6629 the main command set, and now live behind the 'maintenance' command. This
6630 can also be abbreviated as 'mt'. The following changes were made:
6632 dump-me -> maintenance dump-me
6633 info all-breakpoints -> maintenance info breakpoints
6634 printmsyms -> maintenance print msyms
6635 printobjfiles -> maintenance print objfiles
6636 printpsyms -> maintenance print psymbols
6637 printsyms -> maintenance print symbols
6639 The following commands are new:
6641 maintenance demangle Call internal GDB demangler routine to
6642 demangle a C++ link name and prints the result.
6643 maintenance print type Print a type chain for a given symbol
6645 * Change to .gdbinit file processing
6647 We now read the $HOME/.gdbinit file before processing the argv arguments
6648 (e.g. reading symbol files or core files). This allows global parameters to
6649 be set, which will apply during the symbol reading. The ./.gdbinit is still
6650 read after argv processing.
6652 * New hosts supported
6654 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6656 GNU/Linux support i386-unknown-linux or linux
6658 We are also including code to support the HP/PA running BSD and HPUX. This
6659 is almost guaranteed not to work, as we didn't have time to test or build it
6660 for this release. We are including it so that the more adventurous (or
6661 masochistic) of you can play with it. We also had major problems with the
6662 fact that the compiler that we got from HP doesn't support the -g option.
6665 * New targets supported
6667 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6669 * More smarts about finding #include files
6671 GDB now remembers the compilation directory for all include files, and for
6672 all files from which C is generated (like yacc and lex sources). This
6673 greatly improves GDB's ability to find yacc/lex sources, and include files,
6674 especially if you are debugging your program from a directory different from
6675 the one that contains your sources.
6677 We also fixed a bug which caused difficulty with listing and setting
6678 breakpoints in include files which contain C code. (In the past, you had to
6679 try twice in order to list an include file that you hadn't looked at before.)
6681 * Interesting infernals change
6683 GDB now deals with arbitrary numbers of sections, where the symbols for each
6684 section must be relocated relative to that section's landing place in the
6685 target's address space. This work was needed to support ELF with embedded
6686 stabs used by Solaris-2.0.
6688 * Bug fixes (of course!)
6690 There have been loads of fixes for the following things:
6691 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6692 i960, stabs, DOS(GO32), procfs, etc...
6694 See the ChangeLog for details.
6696 *** Changes in GDB-4.5:
6698 * New machines supported (host and target)
6700 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6702 SGI Irix-4.x mips-sgi-irix4 or iris4
6704 * New malloc package
6706 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6707 Mmalloc is capable of handling mutiple heaps of memory. It is also
6708 capable of saving a heap to a file, and then mapping it back in later.
6709 This can be used to greatly speedup the startup of GDB by using a
6710 pre-parsed symbol table which lives in a mmalloc managed heap. For
6711 more details, please read mmalloc/mmalloc.texi.
6715 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6716 'help info proc' for details.
6718 * MIPS ecoff symbol table format
6720 The code that reads MIPS symbol table format is now supported on all hosts.
6721 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6724 * File name changes for MS-DOS
6726 Many files in the config directories have been renamed to make it easier to
6727 support GDB on MS-DOSe systems (which have very restrictive file name
6728 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6729 environment) is close to working but has some remaining problems. Note
6730 that debugging of DOS programs is not supported, due to limitations
6731 in the ``operating system'', but it can be used to host cross-debugging.
6733 * Cross byte order fixes
6735 Many fixes have been made to support cross debugging of Sparc and MIPS
6736 targets from hosts whose byte order differs.
6738 * New -mapped and -readnow options
6740 If memory-mapped files are available on your system through the 'mmap'
6741 system call, you can use the -mapped option on the `file' or
6742 `symbol-file' commands to cause GDB to write the symbols from your
6743 program into a reusable file. If the program you are debugging is
6744 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6745 Future GDB debugging sessions will notice the presence of this file,
6746 and will quickly map in symbol information from it, rather than reading
6747 the symbol table from the executable program. Using the '-mapped'
6748 option in a GDB `file' or `symbol-file' command has the same effect as
6749 starting GDB with the '-mapped' command-line option.
6751 You can cause GDB to read the entire symbol table immediately by using
6752 the '-readnow' option with any of the commands that load symbol table
6753 information (or on the GDB command line). This makes the command
6754 slower, but makes future operations faster.
6756 The -mapped and -readnow options are typically combined in order to
6757 build a `fred.syms' file that contains complete symbol information.
6758 A simple GDB invocation to do nothing but build a `.syms' file for future
6761 gdb -batch -nx -mapped -readnow programname
6763 The `.syms' file is specific to the host machine on which GDB is run.
6764 It holds an exact image of GDB's internal symbol table. It cannot be
6765 shared across multiple host platforms.
6767 * longjmp() handling
6769 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6770 siglongjmp() without losing control. This feature has not yet been ported to
6771 all systems. It currently works on many 386 platforms, all MIPS-based
6772 platforms (SGI, DECstation, etc), and Sun3/4.
6776 Preliminary work has been put in to support the new Solaris OS from Sun. At
6777 this time, it can control and debug processes, but it is not capable of
6782 As always, many many bug fixes. The major areas were with g++, and mipsread.
6783 People using the MIPS-based platforms should experience fewer mysterious
6784 crashes and trashed symbol tables.
6786 *** Changes in GDB-4.4:
6788 * New machines supported (host and target)
6790 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6792 BSD Reno on Vax vax-dec-bsd
6793 Ultrix on Vax vax-dec-ultrix
6795 * New machines supported (target)
6797 AMD 29000 embedded, using EBMON a29k-none-none
6801 GDB continues to improve its handling of C++. `References' work better.
6802 The demangler has also been improved, and now deals with symbols mangled as
6803 per the Annotated C++ Reference Guide.
6805 GDB also now handles `stabs' symbol information embedded in MIPS
6806 `ecoff' symbol tables. Since the ecoff format was not easily
6807 extensible to handle new languages such as C++, this appeared to be a
6808 good way to put C++ debugging info into MIPS binaries. This option
6809 will be supported in the GNU C compiler, version 2, when it is
6812 * New features for SVR4
6814 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6815 shared libraries. Debugging dynamically linked programs should present
6816 only minor differences from debugging statically linked programs.
6818 The `info proc' command will print out information about any process
6819 on an SVR4 system (including the one you are debugging). At the moment,
6820 it prints the address mappings of the process.
6822 If you bring up GDB on another SVR4 system, please send mail to
6823 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6825 * Better dynamic linking support in SunOS
6827 Reading symbols from shared libraries which contain debugging symbols
6828 now works properly. However, there remain issues such as automatic
6829 skipping of `transfer vector' code during function calls, which
6830 make it harder to debug code in a shared library, than to debug the
6831 same code linked statically.
6835 GDB is now using the latest `getopt' routines from the FSF. This
6836 version accepts the -- prefix for options with long names. GDB will
6837 continue to accept the old forms (-option and +option) as well.
6838 Various single letter abbreviations for options have been explicity
6839 added to the option table so that they won't get overshadowed in the
6840 future by other options that begin with the same letter.
6844 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6845 Many assorted bugs have been handled. Many more remain to be handled.
6846 See the various ChangeLog files (primarily in gdb and bfd) for details.
6849 *** Changes in GDB-4.3:
6851 * New machines supported (host and target)
6853 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6854 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6855 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6857 * Almost SCO Unix support
6859 We had hoped to support:
6860 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6861 (except for core file support), but we discovered very late in the release
6862 that it has problems with process groups that render gdb unusable. Sorry
6863 about that. I encourage people to fix it and post the fixes.
6865 * Preliminary ELF and DWARF support
6867 GDB can read ELF object files on System V Release 4, and can handle
6868 debugging records for C, in DWARF format, in ELF files. This support
6869 is preliminary. If you bring up GDB on another SVR4 system, please
6870 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6875 GDB now uses the latest `readline' library. One user-visible change
6876 is that two tabs will list possible command completions, which previously
6877 required typing M-? (meta-question mark, or ESC ?).
6881 The `stepi' bug that many of you noticed has been squashed.
6882 Many bugs in C++ have been handled. Many more remain to be handled.
6883 See the various ChangeLog files (primarily in gdb and bfd) for details.
6885 * State of the MIPS world (in case you wondered):
6887 GDB can understand the symbol tables emitted by the compilers
6888 supplied by most vendors of MIPS-based machines, including DEC. These
6889 symbol tables are in a format that essentially nobody else uses.
6891 Some versions of gcc come with an assembler post-processor called
6892 mips-tfile. This program is required if you want to do source-level
6893 debugging of gcc-compiled programs. I believe FSF does not ship
6894 mips-tfile with gcc version 1, but it will eventually come with gcc
6897 Debugging of g++ output remains a problem. g++ version 1.xx does not
6898 really support it at all. (If you're lucky, you should be able to get
6899 line numbers and stack traces to work, but no parameters or local
6900 variables.) With some work it should be possible to improve the
6903 When gcc version 2 is released, you will have somewhat better luck.
6904 However, even then you will get confusing results for inheritance and
6907 We will eventually provide full debugging of g++ output on
6908 DECstations. This will probably involve some kind of stabs-in-ecoff
6909 encapulation, but the details have not been worked out yet.
6912 *** Changes in GDB-4.2:
6914 * Improved configuration
6916 Only one copy of `configure' exists now, and it is not self-modifying.
6917 Porting BFD is simpler.
6921 The `step' and `next' commands now only stop at the first instruction
6922 of a source line. This prevents the multiple stops that used to occur
6923 in switch statements, for-loops, etc. `Step' continues to stop if a
6924 function that has debugging information is called within the line.
6928 Lots of small bugs fixed. More remain.
6930 * New host supported (not target)
6932 Intel 386 PC clone running Mach i386-none-mach
6935 *** Changes in GDB-4.1:
6937 * Multiple source language support
6939 GDB now has internal scaffolding to handle several source languages.
6940 It determines the type of each source file from its filename extension,
6941 and will switch expression parsing and number formatting to match the
6942 language of the function in the currently selected stack frame.
6943 You can also specifically set the language to be used, with
6944 `set language c' or `set language modula-2'.
6948 GDB now has preliminary support for the GNU Modula-2 compiler,
6949 currently under development at the State University of New York at
6950 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6951 continue through the fall of 1991 and into 1992.
6953 Other Modula-2 compilers are currently not supported, and attempting to
6954 debug programs compiled with them will likely result in an error as the
6955 symbol table is read. Feel free to work on it, though!
6957 There are hooks in GDB for strict type checking and range checking,
6958 in the `Modula-2 philosophy', but they do not currently work.
6962 GDB can now write to executable and core files (e.g. patch
6963 a variable's value). You must turn this switch on, specify
6964 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6965 by assigning a new value to a variable. Modifications take
6968 * Automatic SunOS shared library reading
6970 When you run your program, GDB automatically determines where its
6971 shared libraries (if any) have been loaded, and reads their symbols.
6972 The `share' command is no longer needed. This also works when
6973 examining core files.
6977 You can specify the number of lines that the `list' command shows.
6980 * New machines supported (host and target)
6982 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6983 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6984 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6986 * New hosts supported (not targets)
6988 IBM RT/PC: romp-ibm-aix or rtpc
6990 * New targets supported (not hosts)
6992 AMD 29000 embedded with COFF a29k-none-coff
6993 AMD 29000 embedded with a.out a29k-none-aout
6994 Ultracomputer remote kernel debug a29k-nyu-kern
6996 * New remote interfaces
7002 *** Changes in GDB-4.0:
7006 Wide output is wrapped at good places to make the output more readable.
7008 Gdb now supports cross-debugging from a host machine of one type to a
7009 target machine of another type. Communication with the target system
7010 is over serial lines. The ``target'' command handles connecting to the
7011 remote system; the ``load'' command will download a program into the
7012 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7013 also supports debugging of realtime processes running under VxWorks,
7014 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7015 stub on the target system.
7017 New CPUs supported include the AMD 29000 and Intel 960.
7019 GDB now reads object files and symbol tables via a ``binary file''
7020 library, which allows a single copy of GDB to debug programs of multiple
7021 object file types such as a.out and coff.
7023 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7024 refcard.dvi and refcard.ps are available to format it).
7027 * Control-Variable user interface simplified
7029 All variables that control the operation of the debugger can be set
7030 by the ``set'' command, and displayed by the ``show'' command.
7032 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7033 ``Show prompt'' produces the response:
7034 Gdb's prompt is new-gdb=>.
7036 What follows are the NEW set commands. The command ``help set'' will
7037 print a complete list of old and new set commands. ``help set FOO''
7038 will give a longer description of the variable FOO. ``show'' will show
7039 all of the variable descriptions and their current settings.
7041 confirm on/off: Enables warning questions for operations that are
7042 hard to recover from, e.g. rerunning the program while
7043 it is already running. Default is ON.
7045 editing on/off: Enables EMACS style command line editing
7046 of input. Previous lines can be recalled with
7047 control-P, the current line can be edited with control-B,
7048 you can search for commands with control-R, etc.
7051 history filename NAME: NAME is where the gdb command history
7052 will be stored. The default is .gdb_history,
7053 or the value of the environment variable
7056 history size N: The size, in commands, of the command history. The
7057 default is 256, or the value of the environment variable
7060 history save on/off: If this value is set to ON, the history file will
7061 be saved after exiting gdb. If set to OFF, the
7062 file will not be saved. The default is OFF.
7064 history expansion on/off: If this value is set to ON, then csh-like
7065 history expansion will be performed on
7066 command line input. The default is OFF.
7068 radix N: Sets the default radix for input and output. It can be set
7069 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7070 in the current radix, so "set radix 10" is always a no-op.
7072 height N: This integer value is the number of lines on a page. Default
7073 is 24, the current `stty rows'' setting, or the ``li#''
7074 setting from the termcap entry matching the environment
7077 width N: This integer value is the number of characters on a line.
7078 Default is 80, the current `stty cols'' setting, or the ``co#''
7079 setting from the termcap entry matching the environment
7082 Note: ``set screensize'' is obsolete. Use ``set height'' and
7083 ``set width'' instead.
7085 print address on/off: Print memory addresses in various command displays,
7086 such as stack traces and structure values. Gdb looks
7087 more ``symbolic'' if you turn this off; it looks more
7088 ``machine level'' with it on. Default is ON.
7090 print array on/off: Prettyprint arrays. New convenient format! Default
7093 print demangle on/off: Print C++ symbols in "source" form if on,
7096 print asm-demangle on/off: Same, for assembler level printouts
7099 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7102 * Support for Epoch Environment.
7104 The epoch environment is a version of Emacs v18 with windowing. One
7105 new command, ``inspect'', is identical to ``print'', except that if you
7106 are running in the epoch environment, the value is printed in its own
7110 * Support for Shared Libraries
7112 GDB can now debug programs and core files that use SunOS shared libraries.
7113 Symbols from a shared library cannot be referenced
7114 before the shared library has been linked with the program (this
7115 happens after you type ``run'' and before the function main() is entered).
7116 At any time after this linking (including when examining core files
7117 from dynamically linked programs), gdb reads the symbols from each
7118 shared library when you type the ``sharedlibrary'' command.
7119 It can be abbreviated ``share''.
7121 sharedlibrary REGEXP: Load shared object library symbols for files
7122 matching a unix regular expression. No argument
7123 indicates to load symbols for all shared libraries.
7125 info sharedlibrary: Status of loaded shared libraries.
7130 A watchpoint stops execution of a program whenever the value of an
7131 expression changes. Checking for this slows down execution
7132 tremendously whenever you are in the scope of the expression, but is
7133 quite useful for catching tough ``bit-spreader'' or pointer misuse
7134 problems. Some machines such as the 386 have hardware for doing this
7135 more quickly, and future versions of gdb will use this hardware.
7137 watch EXP: Set a watchpoint (breakpoint) for an expression.
7139 info watchpoints: Information about your watchpoints.
7141 delete N: Deletes watchpoint number N (same as breakpoints).
7142 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7143 enable N: Re-enables watchpoint number N (same as breakpoints).
7146 * C++ multiple inheritance
7148 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7151 * C++ exception handling
7153 Gdb now supports limited C++ exception handling. Besides the existing
7154 ability to breakpoint on an exception handler, gdb can breakpoint on
7155 the raising of an exception (before the stack is peeled back to the
7158 catch FOO: If there is a FOO exception handler in the dynamic scope,
7159 set a breakpoint to catch exceptions which may be raised there.
7160 Multiple exceptions (``catch foo bar baz'') may be caught.
7162 info catch: Lists all exceptions which may be caught in the
7163 current stack frame.
7166 * Minor command changes
7168 The command ``call func (arg, arg, ...)'' now acts like the print
7169 command, except it does not print or save a value if the function's result
7170 is void. This is similar to dbx usage.
7172 The ``up'' and ``down'' commands now always print the frame they end up
7173 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7174 frames without printing.
7176 * New directory command
7178 'dir' now adds directories to the FRONT of the source search path.
7179 The path starts off empty. Source files that contain debug information
7180 about the directory in which they were compiled can be found even
7181 with an empty path; Sun CC and GCC include this information. If GDB can't
7182 find your source file in the current directory, type "dir .".
7184 * Configuring GDB for compilation
7186 For normal use, type ``./configure host''. See README or gdb.texinfo
7189 GDB now handles cross debugging. If you are remotely debugging between
7190 two different machines, type ``./configure host -target=targ''.
7191 Host is the machine where GDB will run; targ is the machine
7192 where the program that you are debugging will run.