1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * New "--readnever" command line option instructs GDB to not read each
7 symbol file's symbolic debug information. This makes startup faster
8 but at the expense of not being able to perform symbolic debugging.
9 This option is intended for use cases where symbolic debugging will
10 not be used, e.g., when you only need to dump the debuggee's core.
12 * GDB now uses the GNU MPFR library, if available, to emulate target
13 floating-point arithmetic during expression evaluation when the target
14 uses different floating-point formats than the host. At least version
15 3.1 of GNU MPFR is required.
17 * GDB now supports access to the guarded-storage-control registers and the
18 software-based guarded-storage broadcast control registers on IBM z14.
20 * On Unix systems, GDB now supports transmitting environment variables
21 that are to be set or unset to GDBserver. These variables will
22 affect the environment to be passed to the remote inferior.
24 To inform GDB of environment variables that are to be transmitted to
25 GDBserver, use the "set environment" command. Only user set
26 environment variables are sent to GDBserver.
28 To inform GDB of environment variables that are to be unset before
29 the remote inferior is started by the GDBserver, use the "unset
32 * Completion improvements
34 ** GDB can now complete function parameters in linespecs and
35 explicit locations without quoting. When setting breakpoints,
36 quoting around functions names to help with TAB-completion is
37 generally no longer necessary. For example, this now completes
40 (gdb) b function(in[TAB]
43 Related, GDB is no longer confused with completing functions in
44 C++ anonymous namespaces:
47 (gdb) b (anonymous namespace)::[TAB][TAB]
48 (anonymous namespace)::a_function()
49 (anonymous namespace)::b_function()
51 ** GDB now has much improved linespec and explicit locations TAB
52 completion support, that better understands what you're
53 completing and offers better suggestions. For example, GDB no
54 longer offers data symbols as possible completions when you're
57 ** GDB now TAB-completes label symbol names.
59 ** The "complete" command now mimics TAB completion accurately.
61 * New command line options (gcore)
64 Dump all memory mappings.
66 * Breakpoints on C++ functions are now set on all scopes by default
68 By default, breakpoints on functions/methods are now interpreted as
69 specifying all functions with the given name ignoring missing
70 leading scopes (namespaces and classes).
72 For example, assuming a C++ program with symbols named:
77 both commands "break func()" and "break B::func()" set a breakpoint
80 You can use the new flag "-qualified" to override this. This makes
81 GDB interpret the specified function name as a complete
82 fully-qualified name instead. For example, using the same C++
83 program, the "break -q B::func" command sets a breakpoint on
86 * Breakpoints on functions marked with C++ ABI tags
88 GDB can now set breakpoints on functions marked with C++ ABI tags
89 (e.g., [abi:cxx11]). See here for a description of ABI tags:
90 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
92 Functions with a C++11 abi tag are demangled/displayed like this:
94 function[abi:cxx11](int)
97 You can now set a breakpoint on such functions simply as if they had
100 (gdb) b function(int)
102 Or if you need to disambiguate between tags, like:
104 (gdb) b function[abi:other_tag](int)
106 Tab completion was adjusted accordingly as well.
110 ** New events gdb.new_inferior, gdb.inferior_deleted, and
111 gdb.new_thread are emitted. See the manual for further
112 description of these.
114 ** A new command, "rbreak" has been added to the Python API. This
115 command allows the setting of a large number of breakpoints via a
116 regex pattern in Python. See the manual for further details.
118 ** Python breakpoints can now accept explicit locations. See the
119 manual for a further description of this feature.
122 * New features in the GDB remote stub, GDBserver
124 ** GDBserver is now able to start inferior processes with a
125 specified initial working directory.
127 The user can set the desired working directory to be used from
128 GDB using the new "set cwd" command.
130 ** New "--selftest" command line option runs some GDBserver self
131 tests. These self tests are disabled in releases.
133 ** On Unix systems, GDBserver now does globbing expansion and variable
134 substitution in inferior command line arguments.
136 This is done by starting inferiors using a shell, like GDB does.
137 See "set startup-with-shell" in the user manual for how to disable
138 this from GDB when using "target extended-remote". When using
139 "target remote", you can disable the startup with shell by using the
140 new "--no-startup-with-shell" GDBserver command line option.
142 ** On Unix systems, GDBserver now supports receiving environment
143 variables that are to be set or unset from GDB. These variables
144 will affect the environment to be passed to the inferior.
146 * When catching an Ada exception raised with a message, GDB now prints
147 the message in the catchpoint hit notification. In GDB/MI mode, that
148 information is provided as an extra field named "exception-message"
149 in the *stopped notification.
151 * Trait objects can now be inspected When debugging Rust code. This
152 requires compiler support which will appear in Rust 1.24.
156 QEnvironmentHexEncoded
157 Inform GDBserver of an environment variable that is to be passed to
158 the inferior when starting it.
161 Inform GDBserver of an environment variable that is to be unset
162 before starting the remote inferior.
165 Inform GDBserver that the environment should be reset (i.e.,
166 user-set environment variables should be unset).
169 Indicates whether the inferior must be started with a shell or not.
172 Tell GDBserver that the inferior to be started should use a specific
175 * The "maintenance print c-tdesc" command now takes an optional
176 argument which is the file name of XML target description.
178 * The "maintenance selftest" command now takes an optional argument to
179 filter the tests to be run.
181 * The "enable", and "disable" commands now accept a range of
182 breakpoint locations, e.g. "enable 1.3-5".
187 Set and show the current working directory for the inferior.
190 Set and show compilation command used for compiling and injecting code
191 with the 'compile' commands.
193 set debug separate-debug-file
194 show debug separate-debug-file
195 Control the display of debug output about separate debug file search.
197 set dump-excluded-mappings
198 show dump-excluded-mappings
199 Control whether mappings marked with the VM_DONTDUMP flag should be
200 dumped when generating a core file.
203 List the registered selftests.
206 Start the debugged program stopping at the first instruction.
208 set|show print type nested-type-limit
209 Set and show the limit of nesting level for nested types that the
210 type printer will show.
212 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
215 * Safer/improved support for debugging with no debug info
217 GDB no longer assumes functions with no debug information return
220 This means that GDB now refuses to call such functions unless you
221 tell it the function's type, by either casting the call to the
222 declared return type, or by casting the function to a function
223 pointer of the right type, and calling that:
225 (gdb) p getenv ("PATH")
226 'getenv' has unknown return type; cast the call to its declared return type
227 (gdb) p (char *) getenv ("PATH")
228 $1 = 0x7fffffffe "/usr/local/bin:/"...
229 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
230 $2 = 0x7fffffffe "/usr/local/bin:/"...
232 Similarly, GDB no longer assumes that global variables with no debug
233 info have type 'int', and refuses to print the variable's value
234 unless you tell it the variable's type:
237 'var' has unknown type; cast it to its declared type
241 * New native configurations
243 FreeBSD/aarch64 aarch64*-*-freebsd*
244 FreeBSD/arm arm*-*-freebsd*
248 FreeBSD/aarch64 aarch64*-*-freebsd*
249 FreeBSD/arm arm*-*-freebsd*
251 * Removed targets and native configurations
253 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
255 *** Changes in GDB 8.0
257 * GDB now supports access to the PKU register on GNU/Linux. The register is
258 added by the Memory Protection Keys for Userspace feature which will be
259 available in future Intel CPUs.
261 * GDB now supports C++11 rvalue references.
265 ** New functions to start, stop and access a running btrace recording.
266 ** Rvalue references are now supported in gdb.Type.
268 * GDB now supports recording and replaying rdrand and rdseed Intel 64
271 * Building GDB and GDBserver now requires a C++11 compiler.
273 For example, GCC 4.8 or later.
275 It is no longer possible to build GDB or GDBserver with a C
276 compiler. The --disable-build-with-cxx configure option has been
279 * Building GDB and GDBserver now requires GNU make >= 3.81.
281 It is no longer supported to build GDB or GDBserver with another
282 implementation of the make program or an earlier version of GNU make.
284 * Native debugging on MS-Windows supports command-line redirection
286 Command-line arguments used for starting programs on MS-Windows can
287 now include redirection symbols supported by native Windows shells,
288 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
289 as "run", "start", and "set args", as well as the corresponding MI
292 * Support for thread names on MS-Windows.
294 GDB now catches and handles the special exception that programs
295 running on MS-Windows use to assign names to threads in the
298 * Support for Java programs compiled with gcj has been removed.
300 * User commands now accept an unlimited number of arguments.
301 Previously, only up to 10 was accepted.
303 * The "eval" command now expands user-defined command arguments.
305 This makes it easier to process a variable number of arguments:
310 eval "print $arg%d", $i
315 * Target descriptions can now describe registers for sparc32 and sparc64.
317 * GDB now supports DWARF version 5 (debug information format).
318 Its .debug_names index is not yet supported.
320 * New native configurations
322 FreeBSD/mips mips*-*-freebsd
326 Synopsys ARC arc*-*-elf32
327 FreeBSD/mips mips*-*-freebsd
329 * Removed targets and native configurations
331 Alpha running FreeBSD alpha*-*-freebsd*
332 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
337 Erases all the flash memory regions reported by the target.
339 maint print arc arc-instruction address
340 Print internal disassembler information about instruction at a given address.
344 set disassembler-options
345 show disassembler-options
346 Controls the passing of target specific information to the disassembler.
347 If it is necessary to specify more than one disassembler option then
348 multiple options can be placed together into a comma separated list.
349 The default value is the empty string. Currently, the only supported
350 targets are ARM, PowerPC and S/390.
355 Erases all the flash memory regions reported by the target. This is
356 equivalent to the CLI command flash-erase.
358 -file-list-shared-libraries
359 List the shared libraries in the program. This is
360 equivalent to the CLI command "info shared".
362 *** Changes in GDB 7.12
364 * GDB and GDBserver now build with a C++ compiler by default.
366 The --enable-build-with-cxx configure option is now enabled by
367 default. One must now explicitly configure with
368 --disable-build-with-cxx in order to build with a C compiler. This
369 option will be removed in a future release.
371 * GDBserver now supports recording btrace without maintaining an active
374 * GDB now supports a negative repeat count in the 'x' command to examine
375 memory backward from the given address. For example:
378 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
379 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
380 (gdb) x/-5i 0x0000000000400580
381 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
382 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
383 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
384 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
385 0x40057b <main(int, char**)+25>:
386 callq 0x400536 <Func1(int, char const*)>
388 * Fortran: Support structures with fields of dynamic types and
389 arrays of dynamic types.
391 * The symbol dumping maintenance commands have new syntax.
392 maint print symbols [-pc address] [--] [filename]
393 maint print symbols [-objfile objfile] [-source source] [--] [filename]
394 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
395 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
396 maint print msymbols [-objfile objfile] [--] [filename]
398 * GDB now supports multibit bitfields and enums in target register
401 * New Python-based convenience function $_as_string(val), which returns
402 the textual representation of a value. This function is especially
403 useful to obtain the text label of an enum value.
405 * Intel MPX bound violation handling.
407 Segmentation faults caused by a Intel MPX boundary violation
408 now display the kind of violation (upper or lower), the memory
409 address accessed and the memory bounds, along with the usual
410 signal received and code location.
414 Program received signal SIGSEGV, Segmentation fault
415 Upper bound violation while accessing address 0x7fffffffc3b3
416 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
417 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
419 * Rust language support.
420 GDB now supports debugging programs written in the Rust programming
421 language. See https://www.rust-lang.org/ for more information about
424 * Support for running interpreters on specified input/output devices
426 GDB now supports a new mechanism that allows frontends to provide
427 fully featured GDB console views, as a better alternative to
428 building such views on top of the "-interpreter-exec console"
429 command. See the new "new-ui" command below. With that command,
430 frontends can now start GDB in the traditional command-line mode
431 running in an embedded terminal emulator widget, and create a
432 separate MI interpreter running on a specified i/o device. In this
433 way, GDB handles line editing, history, tab completion, etc. in the
434 console all by itself, and the GUI uses the separate MI interpreter
435 for its own control and synchronization, invisible to the command
438 * The "catch syscall" command catches groups of related syscalls.
440 The "catch syscall" command now supports catching a group of related
441 syscalls using the 'group:' or 'g:' prefix.
446 skip -gfile file-glob-pattern
447 skip -function function
448 skip -rfunction regular-expression
449 A generalized form of the skip command, with new support for
450 glob-style file names and regular expressions for function names.
451 Additionally, a file spec and a function spec may now be combined.
453 maint info line-table REGEXP
454 Display the contents of GDB's internal line table data struture.
457 Run any GDB unit tests that were compiled in.
460 Start a new user interface instance running INTERP as interpreter,
461 using the TTY file for input/output.
465 ** gdb.Breakpoint objects have a new attribute "pending", which
466 indicates whether the breakpoint is pending.
467 ** Three new breakpoint-related events have been added:
468 gdb.breakpoint_created, gdb.breakpoint_modified, and
469 gdb.breakpoint_deleted.
472 Signal ("set") the given MS-Windows event object. This is used in
473 conjunction with the Windows JIT debugging (AeDebug) support, where
474 the OS suspends a crashing process until a debugger can attach to
475 it. Resuming the crashing process, in order to debug it, is done by
478 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
479 was added in GDBserver, including JIT compiling fast tracepoint's
480 conditional expression bytecode into native code.
482 * Support for various remote target protocols and ROM monitors has
485 target m32rsdi Remote M32R debugging over SDI
486 target mips MIPS remote debugging protocol
487 target pmon PMON ROM monitor
488 target ddb NEC's DDB variant of PMON for Vr4300
489 target rockhopper NEC RockHopper variant of PMON
490 target lsi LSI variant of PMO
492 * Support for tracepoints and fast tracepoints on powerpc-linux,
493 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
494 including JIT compiling fast tracepoint's conditional expression
495 bytecode into native code.
497 * MI async record =record-started now includes the method and format used for
498 recording. For example:
500 =record-started,thread-group="i1",method="btrace",format="bts"
502 * MI async record =thread-selected now includes the frame field. For example:
504 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
508 Andes NDS32 nds32*-*-elf
510 *** Changes in GDB 7.11
512 * GDB now supports debugging kernel-based threads on FreeBSD.
514 * Per-inferior thread numbers
516 Thread numbers are now per inferior instead of global. If you're
517 debugging multiple inferiors, GDB displays thread IDs using a
518 qualified INF_NUM.THR_NUM form. For example:
522 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
523 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
524 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
525 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
527 As consequence, thread numbers as visible in the $_thread
528 convenience variable and in Python's InferiorThread.num attribute
529 are no longer unique between inferiors.
531 GDB now maintains a second thread ID per thread, referred to as the
532 global thread ID, which is the new equivalent of thread numbers in
533 previous releases. See also $_gthread below.
535 For backwards compatibility, MI's thread IDs always refer to global
538 * Commands that accept thread IDs now accept the qualified
539 INF_NUM.THR_NUM form as well. For example:
542 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
545 * In commands that accept a list of thread IDs, you can now refer to
546 all threads of an inferior using a star wildcard. GDB accepts
547 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
548 refer to all threads of the current inferior. For example, "info
551 * You can use "info threads -gid" to display the global thread ID of
554 * The new convenience variable $_gthread holds the global number of
557 * The new convenience variable $_inferior holds the number of the
560 * GDB now displays the ID and name of the thread that hit a breakpoint
561 or received a signal, if your program is multi-threaded. For
564 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
565 Thread 1 "main" received signal SIGINT, Interrupt.
567 * Record btrace now supports non-stop mode.
569 * Support for tracepoints on aarch64-linux was added in GDBserver.
571 * The 'record instruction-history' command now indicates speculative execution
572 when using the Intel Processor Trace recording format.
574 * GDB now allows users to specify explicit locations, bypassing
575 the linespec parser. This feature is also available to GDB/MI
578 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
579 GDB now is able to debug both AArch64 applications and ARM applications
582 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
583 including JIT compiling fast tracepoint's conditional expression bytecode
586 * GDB now supports displaced stepping on AArch64 GNU/Linux.
588 * "info threads", "info inferiors", "info display", "info checkpoints"
589 and "maint info program-spaces" now list the corresponding items in
590 ascending ID order, for consistency with all other "info" commands.
592 * In Ada, the overloads selection menu has been enhanced to display the
593 parameter types and the return types for the matching overloaded subprograms.
597 maint set target-non-stop (on|off|auto)
598 maint show target-non-stop
599 Control whether GDB targets always operate in non-stop mode even if
600 "set non-stop" is "off". The default is "auto", meaning non-stop
601 mode is enabled if supported by the target.
603 maint set bfd-sharing
604 maint show bfd-sharing
605 Control the reuse of bfd objects.
609 Control display of debugging info regarding bfd caching.
613 Control display of debugging info regarding FreeBSD threads.
615 set remote multiprocess-extensions-packet
616 show remote multiprocess-extensions-packet
617 Set/show the use of the remote protocol multiprocess extensions.
619 set remote thread-events
620 show remote thread-events
621 Set/show the use of thread create/exit events.
623 set ada print-signatures on|off
624 show ada print-signatures"
625 Control whether parameter types and return types are displayed in overloads
626 selection menus. It is activaled (@code{on}) by default.
630 Controls the maximum size of memory, in bytes, that GDB will
631 allocate for value contents. Prevents incorrect programs from
632 causing GDB to allocate overly large buffers. Default is 64k.
634 * The "disassemble" command accepts a new modifier: /s.
635 It prints mixed source+disassembly like /m with two differences:
636 - disassembled instructions are now printed in program order, and
637 - and source for all relevant files is now printed.
638 The "/m" option is now considered deprecated: its "source-centric"
639 output hasn't proved useful in practice.
641 * The "record instruction-history" command accepts a new modifier: /s.
642 It behaves exactly like /m and prints mixed source+disassembly.
644 * The "set scheduler-locking" command supports a new mode "replay".
645 It behaves like "off" in record mode and like "on" in replay mode.
647 * Support for various ROM monitors has been removed:
649 target dbug dBUG ROM monitor for Motorola ColdFire
650 target picobug Motorola picobug monitor
651 target dink32 DINK32 ROM monitor for PowerPC
652 target m32r Renesas M32R/D ROM monitor
653 target mon2000 mon2000 ROM monitor
654 target ppcbug PPCBUG ROM monitor for PowerPC
656 * Support for reading/writing memory and extracting values on architectures
657 whose memory is addressable in units of any integral multiple of 8 bits.
662 Indicates that an exec system call was executed.
664 exec-events feature in qSupported
665 The qSupported packet allows GDB to request support for exec
666 events using the new 'gdbfeature' exec-event, and the qSupported
667 response can contain the corresponding 'stubfeature'. Set and
668 show commands can be used to display whether these features are enabled.
671 Equivalent to interrupting with the ^C character, but works in
674 thread created stop reason (T05 create:...)
675 Indicates that the thread was just created and is stopped at entry.
677 thread exit stop reply (w exitcode;tid)
678 Indicates that the thread has terminated.
681 Enables/disables thread create and exit event reporting. For
682 example, this is used in non-stop mode when GDB stops a set of
683 threads and synchronously waits for the their corresponding stop
684 replies. Without exit events, if one of the threads exits, GDB
685 would hang forever not knowing that it should no longer expect a
686 stop for that same thread.
689 Indicates that there are no resumed threads left in the target (all
690 threads are stopped). The remote stub reports support for this stop
691 reply to GDB's qSupported query.
694 Enables/disables catching syscalls from the inferior process.
695 The remote stub reports support for this packet to GDB's qSupported query.
697 syscall_entry stop reason
698 Indicates that a syscall was just called.
700 syscall_return stop reason
701 Indicates that a syscall just returned.
703 * Extended-remote exec events
705 ** GDB now has support for exec events on extended-remote Linux targets.
706 For such targets with Linux kernels 2.5.46 and later, this enables
707 follow-exec-mode and exec catchpoints.
709 set remote exec-event-feature-packet
710 show remote exec-event-feature-packet
711 Set/show the use of the remote exec event feature.
713 * Thread names in remote protocol
715 The reply to qXfer:threads:read may now include a name attribute for each
718 * Target remote mode fork and exec events
720 ** GDB now has support for fork and exec events on target remote mode
721 Linux targets. For such targets with Linux kernels 2.5.46 and later,
722 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
723 fork and exec catchpoints.
725 * Remote syscall events
727 ** GDB now has support for catch syscall on remote Linux targets,
728 currently enabled on x86/x86_64 architectures.
730 set remote catch-syscall-packet
731 show remote catch-syscall-packet
732 Set/show the use of the remote catch syscall feature.
736 ** The -var-set-format command now accepts the zero-hexadecimal
737 format. It outputs data in hexadecimal format with zero-padding on the
742 ** gdb.InferiorThread objects have a new attribute "global_num",
743 which refers to the thread's global thread ID. The existing
744 "num" attribute now refers to the thread's per-inferior number.
745 See "Per-inferior thread numbers" above.
746 ** gdb.InferiorThread objects have a new attribute "inferior", which
747 is the Inferior object the thread belongs to.
749 *** Changes in GDB 7.10
751 * Support for process record-replay and reverse debugging on aarch64*-linux*
752 targets has been added. GDB now supports recording of A64 instruction set
753 including advance SIMD instructions.
755 * Support for Sun's version of the "stabs" debug file format has been removed.
757 * GDB now honors the content of the file /proc/PID/coredump_filter
758 (PID is the process ID) on GNU/Linux systems. This file can be used
759 to specify the types of memory mappings that will be included in a
760 corefile. For more information, please refer to the manual page of
761 "core(5)". GDB also has a new command: "set use-coredump-filter
762 on|off". It allows to set whether GDB will read the content of the
763 /proc/PID/coredump_filter file when generating a corefile.
765 * The "info os" command on GNU/Linux can now display information on
767 "info os cpus" Listing of all cpus/cores on the system
769 * GDB has two new commands: "set serial parity odd|even|none" and
770 "show serial parity". These allows to set or show parity for the
773 * The "info source" command now displays the producer string if it was
774 present in the debug info. This typically includes the compiler version
775 and may include things like its command line arguments.
777 * The "info dll", an alias of the "info sharedlibrary" command,
778 is now available on all platforms.
780 * Directory names supplied to the "set sysroot" commands may be
781 prefixed with "target:" to tell GDB to access shared libraries from
782 the target system, be it local or remote. This replaces the prefix
783 "remote:". The default sysroot has been changed from "" to
784 "target:". "remote:" is automatically converted to "target:" for
785 backward compatibility.
787 * The system root specified by "set sysroot" will be prepended to the
788 filename of the main executable (if reported to GDB as absolute by
789 the operating system) when starting processes remotely, and when
790 attaching to already-running local or remote processes.
792 * GDB now supports automatic location and retrieval of executable
793 files from remote targets. Remote debugging can now be initiated
794 using only a "target remote" or "target extended-remote" command
795 (no "set sysroot" or "file" commands are required). See "New remote
798 * The "dump" command now supports verilog hex format.
800 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
802 * On GNU/Linux, GDB and gdbserver are now able to access executable
803 and shared library files without a "set sysroot" command when
804 attaching to processes running in different mount namespaces from
805 the debugger. This makes it possible to attach to processes in
806 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
807 See "New remote packets" below.
809 * The "tui reg" command now provides completion for all of the
810 available register groups, including target specific groups.
812 * The HISTSIZE environment variable is no longer read when determining
813 the size of GDB's command history. GDB now instead reads the dedicated
814 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
815 disables truncation of command history. Non-numeric values of GDBHISTSIZE
820 ** Memory ports can now be unbuffered.
824 ** gdb.Objfile objects have a new attribute "username",
825 which is the name of the objfile as specified by the user,
826 without, for example, resolving symlinks.
827 ** You can now write frame unwinders in Python.
828 ** gdb.Type objects have a new method "optimized_out",
829 returning optimized out gdb.Value instance of this type.
830 ** gdb.Value objects have new methods "reference_value" and
831 "const_value" which return a reference to the value and a
832 "const" version of the value respectively.
836 maint print symbol-cache
837 Print the contents of the symbol cache.
839 maint print symbol-cache-statistics
840 Print statistics of symbol cache usage.
842 maint flush-symbol-cache
843 Flush the contents of the symbol cache.
847 Start branch trace recording using Branch Trace Store (BTS) format.
850 Evaluate expression by using the compiler and print result.
854 Explicit commands for enabling and disabling tui mode.
857 set mpx bound on i386 and amd64
858 Support for bound table investigation on Intel MPX enabled applications.
862 Start branch trace recording using Intel Processor Trace format.
865 Print information about branch tracing internals.
867 maint btrace packet-history
868 Print the raw branch tracing data.
870 maint btrace clear-packet-history
871 Discard the stored raw branch tracing data.
874 Discard all branch tracing data. It will be fetched and processed
875 anew by the next "record" command.
880 Renamed from "set debug dwarf2-die".
882 Renamed from "show debug dwarf2-die".
885 Renamed from "set debug dwarf2-read".
886 show debug dwarf-read
887 Renamed from "show debug dwarf2-read".
889 maint set dwarf always-disassemble
890 Renamed from "maint set dwarf2 always-disassemble".
891 maint show dwarf always-disassemble
892 Renamed from "maint show dwarf2 always-disassemble".
894 maint set dwarf max-cache-age
895 Renamed from "maint set dwarf2 max-cache-age".
896 maint show dwarf max-cache-age
897 Renamed from "maint show dwarf2 max-cache-age".
900 show debug dwarf-line
901 Control display of debugging info regarding DWARF line processing.
905 Set the maximum number of candidates to be considered during
906 completion. The default value is 200. This limit allows GDB
907 to avoid generating large completion lists, the computation of
908 which can cause the debugger to become temporarily unresponsive.
910 set history remove-duplicates
911 show history remove-duplicates
912 Control the removal of duplicate history entries.
914 maint set symbol-cache-size
915 maint show symbol-cache-size
916 Control the size of the symbol cache.
918 set|show record btrace bts buffer-size
919 Set and show the size of the ring buffer used for branch tracing in
921 The obtained size may differ from the requested size. Use "info
922 record" to see the obtained buffer size.
924 set debug linux-namespaces
925 show debug linux-namespaces
926 Control display of debugging info regarding Linux namespaces.
928 set|show record btrace pt buffer-size
929 Set and show the size of the ring buffer used for branch tracing in
930 Intel Processor Trace format.
931 The obtained size may differ from the requested size. Use "info
932 record" to see the obtained buffer size.
934 maint set|show btrace pt skip-pad
935 Set and show whether PAD packets are skipped when computing the
938 * The command 'thread apply all' can now support new option '-ascending'
939 to call its specified command for all threads in ascending order.
941 * Python/Guile scripting
943 ** GDB now supports auto-loading of Python/Guile scripts contained in the
944 special section named `.debug_gdb_scripts'.
948 qXfer:btrace-conf:read
949 Return the branch trace configuration for the current thread.
951 Qbtrace-conf:bts:size
952 Set the requested ring buffer size for branch tracing in BTS format.
955 Enable Intel Procesor Trace-based branch tracing for the current
956 process. The remote stub reports support for this packet to GDB's
960 Set the requested ring buffer size for branch tracing in Intel Processor
964 Indicates a memory breakpoint instruction was executed, irrespective
965 of whether it was GDB that planted the breakpoint or the breakpoint
966 is hardcoded in the program. This is required for correct non-stop
970 Indicates the target stopped for a hardware breakpoint. This is
971 required for correct non-stop mode operation.
974 Return information about files on the remote system.
977 Return the full absolute name of the file that was executed to
978 create a process running on the remote system.
981 Select the filesystem on which vFile: operations with filename
982 arguments will operate. This is required for GDB to be able to
983 access files on remote targets where the remote stub does not
984 share a common filesystem with the inferior(s).
987 Indicates that a fork system call was executed.
990 Indicates that a vfork system call was executed.
992 vforkdone stop reason
993 Indicates that a vfork child of the specified process has executed
994 an exec or exit, allowing the vfork parent to resume execution.
996 fork-events and vfork-events features in qSupported
997 The qSupported packet allows GDB to request support for fork and
998 vfork events using new 'gdbfeatures' fork-events and vfork-events,
999 and the qSupported response can contain the corresponding
1000 'stubfeatures'. Set and show commands can be used to display
1001 whether these features are enabled.
1003 * Extended-remote fork events
1005 ** GDB now has support for fork events on extended-remote Linux
1006 targets. For targets with Linux kernels 2.5.60 and later, this
1007 enables follow-fork-mode and detach-on-fork for both fork and
1008 vfork, as well as fork and vfork catchpoints.
1010 * The info record command now shows the recording format and the
1011 branch tracing configuration for the current thread when using
1012 the btrace record target.
1013 For the BTS format, it shows the ring buffer size.
1015 * GDB now has support for DTrace USDT (Userland Static Defined
1016 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1018 * GDB now supports access to vector registers on S/390 GNU/Linux
1021 * Removed command line options
1023 -xdb HP-UX XDB compatibility mode.
1025 * Removed targets and native configurations
1027 HP/PA running HP-UX hppa*-*-hpux*
1028 Itanium running HP-UX ia64-*-hpux*
1030 * New configure options
1033 This configure option allows the user to build GDB with support for
1034 Intel Processor Trace (default: auto). This requires libipt.
1036 --with-libipt-prefix=PATH
1037 Specify the path to the version of libipt that GDB should use.
1038 $PATH/include should contain the intel-pt.h header and
1039 $PATH/lib should contain the libipt.so library.
1041 *** Changes in GDB 7.9.1
1045 ** Xmethods can now specify a result type.
1047 *** Changes in GDB 7.9
1049 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1053 ** You can now access frame registers from Python scripts.
1054 ** New attribute 'producer' for gdb.Symtab objects.
1055 ** gdb.Objfile objects have a new attribute "progspace",
1056 which is the gdb.Progspace object of the containing program space.
1057 ** gdb.Objfile objects have a new attribute "owner".
1058 ** gdb.Objfile objects have a new attribute "build_id",
1059 which is the build ID generated when the file was built.
1060 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1061 ** A new event "gdb.clear_objfiles" has been added, triggered when
1062 selecting a new file to debug.
1063 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1064 ** New function gdb.lookup_objfile.
1066 New events which are triggered when GDB modifies the state of the
1069 ** gdb.events.inferior_call_pre: Function call is about to be made.
1070 ** gdb.events.inferior_call_post: Function call has just been made.
1071 ** gdb.events.memory_changed: A memory location has been altered.
1072 ** gdb.events.register_changed: A register has been altered.
1074 * New Python-based convenience functions:
1076 ** $_caller_is(name [, number_of_frames])
1077 ** $_caller_matches(regexp [, number_of_frames])
1078 ** $_any_caller_is(name [, number_of_frames])
1079 ** $_any_caller_matches(regexp [, number_of_frames])
1081 * GDB now supports the compilation and injection of source code into
1082 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1083 to compile the source code to object code, and if successful, inject
1084 and execute that code within the current context of the inferior.
1085 Currently the C language is supported. The commands used to
1086 interface with this new feature are:
1088 compile code [-raw|-r] [--] [source code]
1089 compile file [-raw|-r] filename
1093 demangle [-l language] [--] name
1094 Demangle "name" in the specified language, or the current language
1095 if elided. This command is renamed from the "maint demangle" command.
1096 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1097 as "maint demangler-warning".
1099 queue-signal signal-name-or-number
1100 Queue a signal to be delivered to the thread when it is resumed.
1102 add-auto-load-scripts-directory directory
1103 Add entries to the list of directories from which to load auto-loaded
1106 maint print user-registers
1107 List all currently available "user" registers.
1109 compile code [-r|-raw] [--] [source code]
1110 Compile, inject, and execute in the inferior the executable object
1111 code produced by compiling the provided source code.
1113 compile file [-r|-raw] filename
1114 Compile and inject into the inferior the executable object code
1115 produced by compiling the source code stored in the filename
1118 * On resume, GDB now always passes the signal the program had stopped
1119 for to the thread the signal was sent to, even if the user changed
1120 threads before resuming. Previously GDB would often (but not
1121 always) deliver the signal to the thread that happens to be current
1124 * Conversely, the "signal" command now consistently delivers the
1125 requested signal to the current thread. GDB now asks for
1126 confirmation if the program had stopped for a signal and the user
1127 switched threads meanwhile.
1129 * "breakpoint always-inserted" modes "off" and "auto" merged.
1131 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1132 won't remove breakpoints from the target until all threads stop,
1133 even in non-stop mode. The "auto" mode has been removed, and "off"
1134 is now the default mode.
1138 set debug symbol-lookup
1139 show debug symbol-lookup
1140 Control display of debugging info regarding symbol lookup.
1144 ** The -list-thread-groups command outputs an exit-code field for
1145 inferiors that have exited.
1149 MIPS SDE mips*-sde*-elf*
1153 Support for these obsolete configurations has been removed.
1155 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1156 SGI Irix-5.x mips-*-irix5*
1157 SGI Irix-6.x mips-*-irix6*
1158 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1159 VAX running Ultrix vax-*-ultrix*
1161 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1162 and "assf"), have been removed. Use the "sharedlibrary" command, or
1163 its alias "share", instead.
1165 *** Changes in GDB 7.8
1167 * New command line options
1170 This is an alias for the --data-directory option.
1172 * GDB supports printing and modifying of variable length automatic arrays
1173 as specified in ISO C99.
1175 * The ARM simulator now supports instruction level tracing
1176 with or without disassembly.
1180 GDB now has support for scripting using Guile. Whether this is
1181 available is determined at configure time.
1182 Guile version 2.0 or greater is required.
1183 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1185 * New commands (for set/show, see "New options" below)
1189 Invoke CODE by passing it to the Guile interpreter.
1193 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1195 info auto-load guile-scripts [regexp]
1196 Print the list of automatically loaded Guile scripts.
1198 * The source command is now capable of sourcing Guile scripts.
1199 This feature is dependent on the debugger being built with Guile support.
1203 set print symbol-loading (off|brief|full)
1204 show print symbol-loading
1205 Control whether to print informational messages when loading symbol
1206 information for a file. The default is "full", but when debugging
1207 programs with large numbers of shared libraries the amount of output
1208 becomes less useful.
1210 set guile print-stack (none|message|full)
1211 show guile print-stack
1212 Show a stack trace when an error is encountered in a Guile script.
1214 set auto-load guile-scripts (on|off)
1215 show auto-load guile-scripts
1216 Control auto-loading of Guile script files.
1218 maint ada set ignore-descriptive-types (on|off)
1219 maint ada show ignore-descriptive-types
1220 Control whether the debugger should ignore descriptive types in Ada
1221 programs. The default is not to ignore the descriptive types. See
1222 the user manual for more details on descriptive types and the intended
1223 usage of this option.
1225 set auto-connect-native-target
1227 Control whether GDB is allowed to automatically connect to the
1228 native target for the run, attach, etc. commands when not connected
1229 to any target yet. See also "target native" below.
1231 set record btrace replay-memory-access (read-only|read-write)
1232 show record btrace replay-memory-access
1233 Control what memory accesses are allowed during replay.
1235 maint set target-async (on|off)
1236 maint show target-async
1237 This controls whether GDB targets operate in synchronous or
1238 asynchronous mode. Normally the default is asynchronous, if it is
1239 available; but this can be changed to more easily debug problems
1240 occurring only in synchronous mode.
1242 set mi-async (on|off)
1244 Control whether MI asynchronous mode is preferred. This supersedes
1245 "set target-async" of previous GDB versions.
1247 * "set target-async" is deprecated as a CLI option and is now an alias
1248 for "set mi-async" (only puts MI into async mode).
1250 * Background execution commands (e.g., "c&", "s&", etc.) are now
1251 possible ``out of the box'' if the target supports them. Previously
1252 the user would need to explicitly enable the possibility with the
1253 "set target-async on" command.
1255 * New features in the GDB remote stub, GDBserver
1257 ** New option --debug-format=option1[,option2,...] allows one to add
1258 additional text to each output. At present only timestamps
1259 are supported: --debug-format=timestamps.
1260 Timestamps can also be turned on with the
1261 "monitor set debug-format timestamps" command from GDB.
1263 * The 'record instruction-history' command now starts counting instructions
1264 at one. This also affects the instruction ranges reported by the
1265 'record function-call-history' command when given the /i modifier.
1267 * The command 'record function-call-history' supports a new modifier '/c' to
1268 indent the function names based on their call stack depth.
1269 The fields for the '/i' and '/l' modifier have been reordered.
1270 The source line range is now prefixed with 'at'.
1271 The instruction range is now prefixed with 'inst'.
1272 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1273 "record instruction-history" and "list" commands.
1275 * The ranges given as arguments to the 'record function-call-history' and
1276 'record instruction-history' commands are now inclusive.
1278 * The btrace record target now supports the 'record goto' command.
1279 For locations inside the execution trace, the back trace is computed
1280 based on the information stored in the execution trace.
1282 * The btrace record target supports limited reverse execution and replay.
1283 The target does not record data and therefore does not allow reading
1284 memory or registers.
1286 * The "catch syscall" command now works on s390*-linux* targets.
1288 * The "compare-sections" command is no longer specific to target
1289 remote. It now works with all targets.
1291 * All native targets are now consistently called "native".
1292 Consequently, the "target child", "target GNU", "target djgpp",
1293 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1294 commands have been replaced with "target native". The QNX/NTO port
1295 leaves the "procfs" target in place and adds a "native" target for
1296 consistency with other ports. The impact on users should be minimal
1297 as these commands previously either throwed an error, or were
1298 no-ops. The target's name is visible in the output of the following
1299 commands: "help target", "info target", "info files", "maint print
1302 * The "target native" command now connects to the native target. This
1303 can be used to launch native programs even when "set
1304 auto-connect-native-target" is set to off.
1306 * GDB now supports access to Intel MPX registers on GNU/Linux.
1308 * Support for Intel AVX-512 registers on GNU/Linux.
1309 Support displaying and modifying Intel AVX-512 registers
1310 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1312 * New remote packets
1314 qXfer:btrace:read's annex
1315 The qXfer:btrace:read packet supports a new annex 'delta' to read
1316 branch trace incrementally.
1320 ** Valid Python operations on gdb.Value objects representing
1321 structs/classes invoke the corresponding overloaded operators if
1323 ** New `Xmethods' feature in the Python API. Xmethods are
1324 additional methods or replacements for existing methods of a C++
1325 class. This feature is useful for those cases where a method
1326 defined in C++ source code could be inlined or optimized out by
1327 the compiler, making it unavailable to GDB.
1330 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1332 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1333 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1334 its alias "share", instead.
1336 * The commands "set remotebaud" and "show remotebaud" are no longer
1337 supported. Use "set serial baud" and "show serial baud" (respectively)
1342 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1343 target-async". The latter is left as a deprecated alias of the
1344 former for backward compatibility. If the target supports it,
1345 CLI background execution commands are now always possible by
1346 default, independently of whether the frontend stated a
1347 preference for asynchronous execution with "-gdb-set mi-async".
1348 Previously "-gdb-set target-async off" affected both MI execution
1349 commands and CLI execution commands.
1351 *** Changes in GDB 7.7
1353 * Improved support for process record-replay and reverse debugging on
1354 arm*-linux* targets. Support for thumb32 and syscall instruction
1355 recording has been added.
1357 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1359 * GDB now supports Fission DWP file format version 2.
1360 http://gcc.gnu.org/wiki/DebugFission
1362 * New convenience function "$_isvoid", to check whether an expression
1363 is void. A void expression is an expression where the type of the
1364 result is "void". For example, some convenience variables may be
1365 "void" when evaluated (e.g., "$_exitcode" before the execution of
1366 the program being debugged; or an undefined convenience variable).
1367 Another example, when calling a function whose return type is
1370 * The "maintenance print objfiles" command now takes an optional regexp.
1372 * The "catch syscall" command now works on arm*-linux* targets.
1374 * GDB now consistently shows "<not saved>" when printing values of
1375 registers the debug info indicates have not been saved in the frame
1376 and there's nowhere to retrieve them from
1377 (callee-saved/call-clobbered registers):
1382 (gdb) info registers rax
1385 Before, the former would print "<optimized out>", and the latter
1386 "*value not available*".
1388 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1393 ** Frame filters and frame decorators have been added.
1394 ** Temporary breakpoints are now supported.
1395 ** Line tables representation has been added.
1396 ** New attribute 'parent_type' for gdb.Field objects.
1397 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1398 ** New attribute 'name' for gdb.Type objects.
1402 Nios II ELF nios2*-*-elf
1403 Nios II GNU/Linux nios2*-*-linux
1404 Texas Instruments MSP430 msp430*-*-elf
1406 * Removed native configurations
1408 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1409 been removed. ELF variants of these configurations are kept supported.
1411 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1412 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1413 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1414 i[34567]86-*-openbsd3.[0-3]
1415 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1416 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1417 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1421 Like "catch throw", but catches a re-thrown exception.
1422 maint check-psymtabs
1423 Renamed from old "maint check-symtabs".
1425 Perform consistency checks on symtabs.
1426 maint expand-symtabs
1427 Expand symtabs matching an optional regexp.
1430 Display the details of GDB configure-time options.
1432 maint set|show per-command
1433 maint set|show per-command space
1434 maint set|show per-command time
1435 maint set|show per-command symtab
1436 Enable display of per-command gdb resource usage.
1438 remove-symbol-file FILENAME
1439 remove-symbol-file -a ADDRESS
1440 Remove a symbol file added via add-symbol-file. The file to remove
1441 can be identified by its filename or by an address that lies within
1442 the boundaries of this symbol file in memory.
1445 info exceptions REGEXP
1446 Display the list of Ada exceptions defined in the program being
1447 debugged. If provided, only the exceptions whose names match REGEXP
1452 set debug symfile off|on
1454 Control display of debugging info regarding reading symbol files and
1455 symbol tables within those files
1457 set print raw frame-arguments
1458 show print raw frame-arguments
1459 Set/show whether to print frame arguments in raw mode,
1460 disregarding any defined pretty-printers.
1462 set remote trace-status-packet
1463 show remote trace-status-packet
1464 Set/show the use of remote protocol qTStatus packet.
1468 Control display of debugging messages related to Nios II targets.
1472 Control whether target-assisted range stepping is enabled.
1474 set startup-with-shell
1475 show startup-with-shell
1476 Specifies whether Unix child processes are started via a shell or
1481 Use the target memory cache for accesses to the code segment. This
1482 improves performance of remote debugging (particularly disassembly).
1484 * You can now use a literal value 'unlimited' for options that
1485 interpret 0 or -1 as meaning "unlimited". E.g., "set
1486 trace-buffer-size unlimited" is now an alias for "set
1487 trace-buffer-size -1" and "set height unlimited" is now an alias for
1490 * The "set debug symtab-create" debugging option of GDB has been changed to
1491 accept a verbosity level. 0 means "off", 1 provides basic debugging
1492 output, and values of 2 or greater provides more verbose output.
1494 * New command-line options
1496 Display the details of GDB configure-time options.
1498 * The command 'tsave' can now support new option '-ctf' to save trace
1499 buffer in Common Trace Format.
1501 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1504 * GDB now implements the the C++ 'typeid' operator.
1506 * The new convenience variable $_exception holds the exception being
1507 thrown or caught at an exception-related catchpoint.
1509 * The exception-related catchpoints, like "catch throw", now accept a
1510 regular expression which can be used to filter exceptions by type.
1512 * The new convenience variable $_exitsignal is automatically set to
1513 the terminating signal number when the program being debugged dies
1514 due to an uncaught signal.
1518 ** All MI commands now accept an optional "--language" option.
1519 Support for this feature can be verified by using the "-list-features"
1520 command, which should contain "language-option".
1522 ** The new command -info-gdb-mi-command allows the user to determine
1523 whether a GDB/MI command is supported or not.
1525 ** The "^error" result record returned when trying to execute an undefined
1526 GDB/MI command now provides a variable named "code" whose content is the
1527 "undefined-command" error code. Support for this feature can be verified
1528 by using the "-list-features" command, which should contain
1529 "undefined-command-error-code".
1531 ** The -trace-save MI command can optionally save trace buffer in Common
1534 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1536 ** The command -data-list-register-values now accepts an optional
1537 "--skip-unavailable" option. When used, only the available registers
1540 ** The new command -trace-frame-collected dumps collected variables,
1541 computed expressions, tvars, memory and registers in a traceframe.
1543 ** The commands -stack-list-locals, -stack-list-arguments and
1544 -stack-list-variables now accept an option "--skip-unavailable".
1545 When used, only the available locals or arguments are displayed.
1547 ** The -exec-run command now accepts an optional "--start" option.
1548 When used, the command follows the same semantics as the "start"
1549 command, stopping the program's execution at the start of its
1550 main subprogram. Support for this feature can be verified using
1551 the "-list-features" command, which should contain
1552 "exec-run-start-option".
1554 ** The new commands -catch-assert and -catch-exceptions insert
1555 catchpoints stopping the program when Ada exceptions are raised.
1557 ** The new command -info-ada-exceptions provides the equivalent of
1558 the new "info exceptions" command.
1560 * New system-wide configuration scripts
1561 A GDB installation now provides scripts suitable for use as system-wide
1562 configuration scripts for the following systems:
1566 * GDB now supports target-assigned range stepping with remote targets.
1567 This improves the performance of stepping source lines by reducing
1568 the number of control packets from/to GDB. See "New remote packets"
1571 * GDB now understands the element 'tvar' in the XML traceframe info.
1572 It has the id of the collected trace state variables.
1574 * On S/390 targets that provide the transactional-execution feature,
1575 the program interruption transaction diagnostic block (TDB) is now
1576 represented as a number of additional "registers" in GDB.
1578 * New remote packets
1582 The vCont packet supports a new 'r' action, that tells the remote
1583 stub to step through an address range itself, without GDB
1584 involvemement at each single-step.
1586 qXfer:libraries-svr4:read's annex
1587 The previously unused annex of the qXfer:libraries-svr4:read packet
1588 is now used to support passing an argument list. The remote stub
1589 reports support for this argument list to GDB's qSupported query.
1590 The defined arguments are "start" and "prev", used to reduce work
1591 necessary for library list updating, resulting in significant
1594 * New features in the GDB remote stub, GDBserver
1596 ** GDBserver now supports target-assisted range stepping. Currently
1597 enabled on x86/x86_64 GNU/Linux targets.
1599 ** GDBserver now adds element 'tvar' in the XML in the reply to
1600 'qXfer:traceframe-info:read'. It has the id of the collected
1601 trace state variables.
1603 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1606 * New 'z' formatter for printing and examining memory, this displays the
1607 value as hexadecimal zero padded on the left to the size of the type.
1609 * GDB can now use Windows x64 unwinding data.
1611 * The "set remotebaud" command has been replaced by "set serial baud".
1612 Similarly, "show remotebaud" has been replaced by "show serial baud".
1613 The "set remotebaud" and "show remotebaud" commands are still available
1614 to provide backward compatibility with older versions of GDB.
1616 *** Changes in GDB 7.6
1618 * Target record has been renamed to record-full.
1619 Record/replay is now enabled with the "record full" command.
1620 This also affects settings that are associated with full record/replay
1621 that have been moved from "set/show record" to "set/show record full":
1623 set|show record full insn-number-max
1624 set|show record full stop-at-limit
1625 set|show record full memory-query
1627 * A new record target "record-btrace" has been added. The new target
1628 uses hardware support to record the control-flow of a process. It
1629 does not support replaying the execution, but it implements the
1630 below new commands for investigating the recorded execution log.
1631 This new recording method can be enabled using:
1635 The "record-btrace" target is only available on Intel Atom processors
1636 and requires a Linux kernel 2.6.32 or later.
1638 * Two new commands have been added for record/replay to give information
1639 about the recorded execution without having to replay the execution.
1640 The commands are only supported by "record btrace".
1642 record instruction-history prints the execution history at
1643 instruction granularity
1645 record function-call-history prints the execution history at
1646 function granularity
1648 * New native configurations
1650 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1651 FreeBSD/powerpc powerpc*-*-freebsd
1652 x86_64/Cygwin x86_64-*-cygwin*
1653 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1657 ARM AArch64 aarch64*-*-elf
1658 ARM AArch64 GNU/Linux aarch64*-*-linux
1659 Lynx 178 PowerPC powerpc-*-lynx*178
1660 x86_64/Cygwin x86_64-*-cygwin*
1661 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1663 * If the configured location of system.gdbinit file (as given by the
1664 --with-system-gdbinit option at configure time) is in the
1665 data-directory (as specified by --with-gdb-datadir at configure
1666 time) or in one of its subdirectories, then GDB will look for the
1667 system-wide init file in the directory specified by the
1668 --data-directory command-line option.
1670 * New command line options:
1672 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1673 other initialization files, unlike -nx which disables all of them.
1675 * Removed command line options
1677 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1680 * The 'ptype' and 'whatis' commands now accept an argument to control
1683 * 'info proc' now works on some core files.
1687 ** Vectors can be created with gdb.Type.vector.
1689 ** Python's atexit.register now works in GDB.
1691 ** Types can be pretty-printed via a Python API.
1693 ** Python 3 is now supported (in addition to Python 2.4 or later)
1695 ** New class gdb.Architecture exposes GDB's internal representation
1696 of architecture in the Python API.
1698 ** New method Frame.architecture returns the gdb.Architecture object
1699 corresponding to the frame's architecture.
1701 * New Python-based convenience functions:
1703 ** $_memeq(buf1, buf2, length)
1704 ** $_streq(str1, str2)
1706 ** $_regex(str, regex)
1708 * The 'cd' command now defaults to using '~' (the home directory) if not
1711 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1712 default for GCC since November 2000.
1714 * The command 'forward-search' can now be abbreviated as 'fo'.
1716 * The command 'info tracepoints' can now display 'installed on target'
1717 or 'not installed on target' for each non-pending location of tracepoint.
1719 * New configure options
1721 --enable-libmcheck/--disable-libmcheck
1722 By default, development versions are built with -lmcheck on hosts
1723 that support it, in order to help track memory corruption issues.
1724 Release versions, on the other hand, are built without -lmcheck
1725 by default. The --enable-libmcheck/--disable-libmcheck configure
1726 options allow the user to override that default.
1727 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1728 This configure option allows the user to build GDB with
1729 libbabeltrace using which GDB can read Common Trace Format data.
1731 * New commands (for set/show, see "New options" below)
1734 Catch signals. This is similar to "handle", but allows commands and
1735 conditions to be attached.
1738 List the BFDs known to GDB.
1740 python-interactive [command]
1742 Start a Python interactive prompt, or evaluate the optional command
1743 and print the result of expressions.
1746 "py" is a new alias for "python".
1748 enable type-printer [name]...
1749 disable type-printer [name]...
1750 Enable or disable type printers.
1754 ** For the Renesas Super-H architecture, the "regs" command has been removed
1755 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1760 set print type methods (on|off)
1761 show print type methods
1762 Control whether method declarations are displayed by "ptype".
1763 The default is to show them.
1765 set print type typedefs (on|off)
1766 show print type typedefs
1767 Control whether typedef definitions are displayed by "ptype".
1768 The default is to show them.
1770 set filename-display basename|relative|absolute
1771 show filename-display
1772 Control the way in which filenames is displayed.
1773 The default is "relative", which preserves previous behavior.
1775 set trace-buffer-size
1776 show trace-buffer-size
1777 Request target to change the size of trace buffer.
1779 set remote trace-buffer-size-packet auto|on|off
1780 show remote trace-buffer-size-packet
1781 Control the use of the remote protocol `QTBuffer:size' packet.
1785 Control display of debugging messages related to ARM AArch64.
1788 set debug coff-pe-read
1789 show debug coff-pe-read
1790 Control display of debugging messages related to reading of COFF/PE
1795 Control display of debugging messages related to Mach-O symbols
1798 set debug notification
1799 show debug notification
1800 Control display of debugging info for async remote notification.
1804 ** Command parameter changes are now notified using new async record
1805 "=cmd-param-changed".
1806 ** Trace frame changes caused by command "tfind" are now notified using
1807 new async record "=traceframe-changed".
1808 ** The creation, deletion and modification of trace state variables
1809 are now notified using new async records "=tsv-created",
1810 "=tsv-deleted" and "=tsv-modified".
1811 ** The start and stop of process record are now notified using new
1812 async record "=record-started" and "=record-stopped".
1813 ** Memory changes are now notified using new async record
1815 ** The data-disassemble command response will include a "fullname" field
1816 containing the absolute file name when source has been requested.
1817 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1818 command, to allow pattern filling of memory areas.
1819 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1820 library load/unload events.
1821 ** The response to breakpoint commands and breakpoint async records
1822 includes an "installed" field containing a boolean state about each
1823 non-pending tracepoint location is whether installed on target or not.
1824 ** Output of the "-trace-status" command includes a "trace-file" field
1825 containing the name of the trace file being examined. This field is
1826 optional, and only present when examining a trace file.
1827 ** The "fullname" field is now always present along with the "file" field,
1828 even if the file cannot be found by GDB.
1830 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1831 You must have the LZMA library available when configuring GDB for this
1832 feature to be enabled. For more information, see:
1833 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1835 * New remote packets
1838 Set the size of trace buffer. The remote stub reports support for this
1839 packet to gdb's qSupported query.
1842 Enable Branch Trace Store (BTS)-based branch tracing for the current
1843 thread. The remote stub reports support for this packet to gdb's
1847 Disable branch tracing for the current thread. The remote stub reports
1848 support for this packet to gdb's qSupported query.
1851 Read the traced branches for the current thread. The remote stub
1852 reports support for this packet to gdb's qSupported query.
1854 *** Changes in GDB 7.5
1856 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1857 for more x32 ABI info.
1859 * GDB now supports access to MIPS DSP registers on Linux targets.
1861 * GDB now supports debugging microMIPS binaries.
1863 * The "info os" command on GNU/Linux can now display information on
1864 several new classes of objects managed by the operating system:
1865 "info os procgroups" lists process groups
1866 "info os files" lists file descriptors
1867 "info os sockets" lists internet-domain sockets
1868 "info os shm" lists shared-memory regions
1869 "info os semaphores" lists semaphores
1870 "info os msg" lists message queues
1871 "info os modules" lists loaded kernel modules
1873 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1874 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1875 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1876 options and inspect the probe arguments using the new $_probe_arg family
1877 of convenience variables. You can obtain more information about SystemTap
1878 in <http://sourceware.org/systemtap/>.
1880 * GDB now supports reversible debugging on ARM, it allows you to
1881 debug basic ARM and THUMB instructions, and provides
1882 record/replay support.
1884 * The option "symbol-reloading" has been deleted as it is no longer used.
1888 ** GDB commands implemented in Python can now be put in command class
1891 ** The "maint set python print-stack on|off" is now deleted.
1893 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1894 apply "flag enum"-style pretty-printing to any enum.
1896 ** gdb.lookup_symbol can now work when there is no current frame.
1898 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1899 the source at which the symbol was defined.
1901 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1902 method 'value'. The former indicates whether the symbol needs a
1903 frame in order to compute its value, and the latter computes the
1906 ** A new method 'referenced_value' on gdb.Value objects which can
1907 dereference pointer as well as C++ reference values.
1909 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1910 which return the global and static blocks (as gdb.Block objects),
1911 of the underlying symbol table, respectively.
1913 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1914 object associated with a PC value.
1916 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1917 of the address range occupied by code for the current source line.
1919 * Go language support.
1920 GDB now supports debugging programs written in the Go programming
1923 * GDBserver now supports stdio connections.
1924 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1926 * The binary "gdbtui" can no longer be built or installed.
1927 Use "gdb -tui" instead.
1929 * GDB will now print "flag" enums specially. A flag enum is one where
1930 all the enumerator values have no bits in common when pairwise
1931 "and"ed. When printing a value whose type is a flag enum, GDB will
1932 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1933 (gdb) print (enum E) 3
1936 * The filename part of a linespec will now match trailing components
1937 of a source file name. For example, "break gcc/expr.c:1000" will
1938 now set a breakpoint in build/gcc/expr.c, but not
1939 build/libcpp/expr.c.
1941 * The "info proc" and "generate-core-file" commands will now also
1942 work on remote targets connected to GDBserver on Linux.
1944 * The command "info catch" has been removed. It has been disabled
1945 since December 2007.
1947 * The "catch exception" and "catch assert" commands now accept
1948 a condition at the end of the command, much like the "break"
1949 command does. For instance:
1951 (gdb) catch exception Constraint_Error if Barrier = True
1953 Previously, it was possible to add a condition to such catchpoints,
1954 but it had to be done as a second step, after the catchpoint had been
1955 created, using the "condition" command.
1957 * The "info static-tracepoint-marker" command will now also work on
1958 native Linux targets with in-process agent.
1960 * GDB can now set breakpoints on inlined functions.
1962 * The .gdb_index section has been updated to include symbols for
1963 inlined functions. GDB will ignore older .gdb_index sections by
1964 default, which could cause symbol files to be loaded more slowly
1965 until their .gdb_index sections can be recreated. The new command
1966 "set use-deprecated-index-sections on" will cause GDB to use any older
1967 .gdb_index sections it finds. This will restore performance, but the
1968 ability to set breakpoints on inlined functions will be lost in symbol
1969 files with older .gdb_index sections.
1971 The .gdb_index section has also been updated to record more information
1972 about each symbol. This speeds up the "info variables", "info functions"
1973 and "info types" commands when used with programs having the .gdb_index
1974 section, as well as speeding up debugging with shared libraries using
1975 the .gdb_index section.
1977 * Ada support for GDB/MI Variable Objects has been added.
1979 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1984 ** New command -info-os is the MI equivalent of "info os".
1986 ** Output logs ("set logging" and related) now include MI output.
1990 ** "set use-deprecated-index-sections on|off"
1991 "show use-deprecated-index-sections on|off"
1992 Controls the use of deprecated .gdb_index sections.
1994 ** "catch load" and "catch unload" can be used to stop when a shared
1995 library is loaded or unloaded, respectively.
1997 ** "enable count" can be used to auto-disable a breakpoint after
2000 ** "info vtbl" can be used to show the virtual method tables for
2001 C++ and Java objects.
2003 ** "explore" and its sub commands "explore value" and "explore type"
2004 can be used to recursively explore values and types of
2005 expressions. These commands are available only if GDB is
2006 configured with '--with-python'.
2008 ** "info auto-load" shows status of all kinds of auto-loaded files,
2009 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2010 sequences of commands files, "info auto-load python-scripts"
2011 shows status of auto-loading Python script files,
2012 "info auto-load local-gdbinit" shows status of loading init file
2013 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2014 status of inferior specific thread debugging shared library loading.
2016 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2017 and "show auto-load-scripts" commands have been deprecated, use their
2018 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2019 and "show auto-load python-scripts" counterparts instead.
2021 ** "dprintf location,format,args..." creates a dynamic printf, which
2022 is basically a breakpoint that does a printf and immediately
2023 resumes your program's execution, so it is like a printf that you
2024 can insert dynamically at runtime instead of at compiletime.
2026 ** "set print symbol"
2028 Controls whether GDB attempts to display the symbol, if any,
2029 corresponding to addresses it prints. This defaults to "on", but
2030 you can set it to "off" to restore GDB's previous behavior.
2032 * Deprecated commands
2034 ** For the Renesas Super-H architecture, the "regs" command has been
2035 deprecated, and "info all-registers" should be used instead.
2039 Renesas RL78 rl78-*-elf
2040 HP OpenVMS ia64 ia64-hp-openvms*
2042 * GDBserver supports evaluation of breakpoint conditions. When
2043 support is advertised by GDBserver, GDB may be told to send the
2044 breakpoint conditions in bytecode form to GDBserver. GDBserver
2045 will only report the breakpoint trigger to GDB when its condition
2050 set mips compression
2051 show mips compression
2052 Select the compressed ISA encoding used in functions that have no symbol
2053 information available. The encoding can be set to either of:
2056 and is updated automatically from ELF file flags if available.
2058 set breakpoint condition-evaluation
2059 show breakpoint condition-evaluation
2060 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2061 GDBserver ("target"). Default option "auto" chooses the most efficient
2063 This option can improve debugger efficiency depending on the speed of the
2067 Disable auto-loading globally.
2070 Show auto-loading setting of all kinds of auto-loaded files.
2072 set auto-load gdb-scripts on|off
2073 show auto-load gdb-scripts
2074 Control auto-loading of GDB canned sequences of commands files.
2076 set auto-load python-scripts on|off
2077 show auto-load python-scripts
2078 Control auto-loading of Python script files.
2080 set auto-load local-gdbinit on|off
2081 show auto-load local-gdbinit
2082 Control loading of init file (.gdbinit) from current directory.
2084 set auto-load libthread-db on|off
2085 show auto-load libthread-db
2086 Control auto-loading of inferior specific thread debugging shared library.
2088 set auto-load scripts-directory <dir1>[:<dir2>...]
2089 show auto-load scripts-directory
2090 Set a list of directories from which to load auto-loaded scripts.
2091 Automatically loaded Python scripts and GDB scripts are located in one
2092 of the directories listed by this option.
2093 The delimiter (':' above) may differ according to the host platform.
2095 set auto-load safe-path <dir1>[:<dir2>...]
2096 show auto-load safe-path
2097 Set a list of directories from which it is safe to auto-load files.
2098 The delimiter (':' above) may differ according to the host platform.
2100 set debug auto-load on|off
2101 show debug auto-load
2102 Control display of debugging info for auto-loading the files above.
2104 set dprintf-style gdb|call|agent
2106 Control the way in which a dynamic printf is performed; "gdb"
2107 requests a GDB printf command, while "call" causes dprintf to call a
2108 function in the inferior. "agent" requests that the target agent
2109 (such as GDBserver) do the printing.
2111 set dprintf-function <expr>
2112 show dprintf-function
2113 set dprintf-channel <expr>
2114 show dprintf-channel
2115 Set the function and optional first argument to the call when using
2116 the "call" style of dynamic printf.
2118 set disconnected-dprintf on|off
2119 show disconnected-dprintf
2120 Control whether agent-style dynamic printfs continue to be in effect
2121 after GDB disconnects.
2123 * New configure options
2125 --with-auto-load-dir
2126 Configure default value for the 'set auto-load scripts-directory'
2127 setting above. It defaults to '$debugdir:$datadir/auto-load',
2128 $debugdir representing global debugging info directories (available
2129 via 'show debug-file-directory') and $datadir representing GDB's data
2130 directory (available via 'show data-directory').
2132 --with-auto-load-safe-path
2133 Configure default value for the 'set auto-load safe-path' setting
2134 above. It defaults to the --with-auto-load-dir setting.
2136 --without-auto-load-safe-path
2137 Set 'set auto-load safe-path' to '/', effectively disabling this
2140 * New remote packets
2142 z0/z1 conditional breakpoints extension
2144 The z0/z1 breakpoint insertion packets have been extended to carry
2145 a list of conditional expressions over to the remote stub depending on the
2146 condition evaluation mode. The use of this extension can be controlled
2147 via the "set remote conditional-breakpoints-packet" command.
2151 Specify the signals which the remote stub may pass to the debugged
2152 program without GDB involvement.
2154 * New command line options
2156 --init-command=FILE, -ix Like --command, -x but execute it
2157 before loading inferior.
2158 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2159 execute it before loading inferior.
2161 *** Changes in GDB 7.4
2163 * GDB now handles ambiguous linespecs more consistently; the existing
2164 FILE:LINE support has been expanded to other types of linespecs. A
2165 breakpoint will now be set on all matching locations in all
2166 inferiors, and locations will be added or removed according to
2169 * GDB now allows you to skip uninteresting functions and files when
2170 stepping with the "skip function" and "skip file" commands.
2172 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2173 and "show remote hardware-watchpoint-length-limit". These allows to
2174 set or show the maximum length limit (in bytes) of a remote
2175 target hardware watchpoint.
2177 This allows e.g. to use "unlimited" hardware watchpoints with the
2178 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2179 watchpoints are slower than real hardware watchpoints but are
2180 significantly faster than gdb software watchpoints.
2184 ** The register_pretty_printer function in module gdb.printing now takes
2185 an optional `replace' argument. If True, the new printer replaces any
2188 ** The "maint set python print-stack on|off" command has been
2189 deprecated and will be deleted in GDB 7.5.
2190 A new command: "set python print-stack none|full|message" has
2191 replaced it. Additionally, the default for "print-stack" is
2192 now "message", which just prints the error message without
2195 ** A prompt substitution hook (prompt_hook) is now available to the
2198 ** A new Python module, gdb.prompt has been added to the GDB Python
2199 modules library. This module provides functionality for
2200 escape sequences in prompts (used by set/show
2201 extended-prompt). These escape sequences are replaced by their
2202 corresponding value.
2204 ** Python commands and convenience-functions located in
2205 'data-directory'/python/gdb/command and
2206 'data-directory'/python/gdb/function are now automatically loaded
2209 ** Blocks now provide four new attributes. global_block and
2210 static_block will return the global and static blocks
2211 respectively. is_static and is_global are boolean attributes
2212 that indicate if the block is one of those two types.
2214 ** Symbols now provide the "type" attribute, the type of the symbol.
2216 ** The "gdb.breakpoint" function has been deprecated in favor of
2219 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2220 of a function. This class is based on the "finish" command
2221 available in the CLI.
2223 ** Type objects for struct and union types now allow access to
2224 the fields using standard Python dictionary (mapping) methods.
2225 For example, "some_type['myfield']" now works, as does
2226 "some_type.items()".
2228 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2231 ** A new function, "deep_items" has been added to the gdb.types
2232 module in the GDB Python modules library. This function returns
2233 an iterator over the fields of a struct or union type. Unlike
2234 the standard Python "iteritems" method, it will recursively traverse
2235 any anonymous fields.
2239 ** "*stopped" events can report several new "reason"s, such as
2242 ** Breakpoint changes are now notified using new async records, like
2243 "=breakpoint-modified".
2245 ** New command -ada-task-info.
2247 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2248 $sdir specifies the default system locations of shared libraries.
2249 $pdir specifies the directory where the libpthread used by the application
2252 GDB no longer looks in $sdir and $pdir after it has searched the directories
2253 mentioned in libthread-db-search-path. If you want to search those
2254 directories, they must be specified in libthread-db-search-path.
2255 The default value of libthread-db-search-path on GNU/Linux and Solaris
2256 systems is now "$sdir:$pdir".
2258 $pdir is not supported by gdbserver, it is currently ignored.
2259 $sdir is supported by gdbserver.
2261 * New configure option --with-iconv-bin.
2262 When using the internationalization support like the one in the GNU C
2263 library, GDB will invoke the "iconv" program to get a list of supported
2264 character sets. If this program lives in a non-standard location, one can
2265 use this option to specify where to find it.
2267 * When natively debugging programs on PowerPC BookE processors running
2268 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2269 watchpoints, which specify a mask in addition to an address to watch.
2270 The mask specifies that some bits of an address (the bits which are
2271 reset in the mask) should be ignored when matching the address accessed
2272 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2273 section in the user manual for more details.
2275 * The new option --once causes GDBserver to stop listening for connections once
2276 the first connection is made. The listening port used by GDBserver will
2277 become available after that.
2279 * New commands "info macros" and "alias" have been added.
2281 * New function parameters suffix @entry specifies value of function parameter
2282 at the time the function got called. Entry values are available only since
2288 "!" is now an alias of the "shell" command.
2289 Note that no space is needed between "!" and SHELL COMMAND.
2293 watch EXPRESSION mask MASK_VALUE
2294 The watch command now supports the mask argument which allows creation
2295 of masked watchpoints, if the current architecture supports this feature.
2297 info auto-load-scripts [REGEXP]
2298 This command was formerly named "maintenance print section-scripts".
2299 It is now generally useful and is no longer a maintenance-only command.
2301 info macro [-all] [--] MACRO
2302 The info macro command has new options `-all' and `--'. The first for
2303 printing all definitions of a macro. The second for explicitly specifying
2304 the end of arguments and the beginning of the macro name in case the macro
2305 name starts with a hyphen.
2307 collect[/s] EXPRESSIONS
2308 The tracepoint collect command now takes an optional modifier "/s"
2309 that directs it to dereference pointer-to-character types and
2310 collect the bytes of memory up to a zero byte. The behavior is
2311 similar to what you see when you use the regular print command on a
2312 string. An optional integer following the "/s" sets a bound on the
2313 number of bytes that will be collected.
2316 The trace start command now interprets any supplied arguments as a
2317 note to be recorded with the trace run, with an effect similar to
2318 setting the variable trace-notes.
2321 The trace stop command now interprets any arguments as a note to be
2322 mentioned along with the tstatus report that the trace was stopped
2323 with a command. The effect is similar to setting the variable
2326 * Tracepoints can now be enabled and disabled at any time after a trace
2327 experiment has been started using the standard "enable" and "disable"
2328 commands. It is now possible to start a trace experiment with no enabled
2329 tracepoints; GDB will display a warning, but will allow the experiment to
2330 begin, assuming that tracepoints will be enabled as needed while the trace
2333 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2334 locations with 4-byte instructions, when they were previously
2335 limited to locations with instructions of 5 bytes or longer.
2339 set debug dwarf2-read
2340 show debug dwarf2-read
2341 Turns on or off display of debugging messages related to reading
2342 DWARF debug info. The default is off.
2344 set debug symtab-create
2345 show debug symtab-create
2346 Turns on or off display of debugging messages related to symbol table
2347 creation. The default is off.
2350 show extended-prompt
2351 Set the GDB prompt, and allow escape sequences to be inserted to
2352 display miscellaneous information (see 'help set extended-prompt'
2353 for the list of sequences). This prompt (and any information
2354 accessed through the escape sequences) is updated every time the
2355 prompt is displayed.
2357 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2358 show print entry-values
2359 Set printing of frame argument values at function entry. In some cases
2360 GDB can determine the value of function argument which was passed by the
2361 function caller, even if the value was modified inside the called function.
2363 set debug entry-values
2364 show debug entry-values
2365 Control display of debugging info for determining frame argument values at
2366 function entry and virtual tail call frames.
2368 set basenames-may-differ
2369 show basenames-may-differ
2370 Set whether a source file may have multiple base names.
2371 (A "base name" is the name of a file with the directory part removed.
2372 Example: The base name of "/home/user/hello.c" is "hello.c".)
2373 If set, GDB will canonicalize file names (e.g., expand symlinks)
2374 before comparing them. Canonicalization is an expensive operation,
2375 but it allows the same file be known by more than one base name.
2376 If not set (the default), all source files are assumed to have just
2377 one base name, and gdb will do file name comparisons more efficiently.
2383 Set a user name and notes for the current and any future trace runs.
2384 This is useful for long-running and/or disconnected traces, to
2385 inform others (or yourself) as to who is running the trace, supply
2386 contact information, or otherwise explain what is going on.
2388 set trace-stop-notes
2389 show trace-stop-notes
2390 Set a note attached to the trace run, that is displayed when the
2391 trace has been stopped by a tstop command. This is useful for
2392 instance as an explanation, if you are stopping a trace run that was
2393 started by someone else.
2395 * New remote packets
2399 Dynamically enable a tracepoint in a started trace experiment.
2403 Dynamically disable a tracepoint in a started trace experiment.
2407 Set the user and notes of the trace run.
2411 Query the current status of a tracepoint.
2415 Query the minimum length of instruction at which a fast tracepoint may
2418 * Dcache size (number of lines) and line-size are now runtime-configurable
2419 via "set dcache line" and "set dcache line-size" commands.
2423 Texas Instruments TMS320C6x tic6x-*-*
2427 Renesas RL78 rl78-*-elf
2429 *** Changes in GDB 7.3.1
2431 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2433 *** Changes in GDB 7.3
2435 * GDB has a new command: "thread find [REGEXP]".
2436 It finds the thread id whose name, target id, or thread extra info
2437 matches the given regular expression.
2439 * The "catch syscall" command now works on mips*-linux* targets.
2441 * The -data-disassemble MI command now supports modes 2 and 3 for
2442 dumping the instruction opcodes.
2444 * New command line options
2446 -data-directory DIR Specify DIR as the "data-directory".
2447 This is mostly for testing purposes.
2449 * The "maint set python auto-load on|off" command has been renamed to
2450 "set auto-load-scripts on|off".
2452 * GDB has a new command: "set directories".
2453 It is like the "dir" command except that it replaces the
2454 source path list instead of augmenting it.
2456 * GDB now understands thread names.
2458 On GNU/Linux, "info threads" will display the thread name as set by
2459 prctl or pthread_setname_np.
2461 There is also a new command, "thread name", which can be used to
2462 assign a name internally for GDB to display.
2465 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2466 has been integrated into GDB.
2470 ** The function gdb.Write now accepts an optional keyword 'stream'.
2471 This keyword, when provided, will direct the output to either
2472 stdout, stderr, or GDB's logging output.
2474 ** Parameters can now be be sub-classed in Python, and in particular
2475 you may implement the get_set_doc and get_show_doc functions.
2476 This improves how Parameter set/show documentation is processed
2477 and allows for more dynamic content.
2479 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2480 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2481 have an is_valid method.
2483 ** Breakpoints can now be sub-classed in Python, and in particular
2484 you may implement a 'stop' function that is executed each time
2485 the inferior reaches that breakpoint.
2487 ** New function gdb.lookup_global_symbol looks up a global symbol.
2489 ** GDB values in Python are now callable if the value represents a
2490 function. For example, if 'some_value' represents a function that
2491 takes two integer parameters and returns a value, you can call
2492 that function like so:
2494 result = some_value (10,20)
2496 ** Module gdb.types has been added.
2497 It contains a collection of utilities for working with gdb.Types objects:
2498 get_basic_type, has_field, make_enum_dict.
2500 ** Module gdb.printing has been added.
2501 It contains utilities for writing and registering pretty-printers.
2502 New classes: PrettyPrinter, SubPrettyPrinter,
2503 RegexpCollectionPrettyPrinter.
2504 New function: register_pretty_printer.
2506 ** New commands "info pretty-printers", "enable pretty-printer" and
2507 "disable pretty-printer" have been added.
2509 ** gdb.parameter("directories") is now available.
2511 ** New function gdb.newest_frame returns the newest frame in the
2514 ** The gdb.InferiorThread class has a new "name" attribute. This
2515 holds the thread's name.
2517 ** Python Support for Inferior events.
2518 Python scripts can add observers to be notified of events
2519 occurring in the process being debugged.
2520 The following events are currently supported:
2521 - gdb.events.cont Continue event.
2522 - gdb.events.exited Inferior exited event.
2523 - gdb.events.stop Signal received, and Breakpoint hit events.
2527 ** GDB now puts template parameters in scope when debugging in an
2528 instantiation. For example, if you have:
2530 template<int X> int func (void) { return X; }
2532 then if you step into func<5>, "print X" will show "5". This
2533 feature requires proper debuginfo support from the compiler; it
2534 was added to GCC 4.5.
2536 ** The motion commands "next", "finish", "until", and "advance" now
2537 work better when exceptions are thrown. In particular, GDB will
2538 no longer lose control of the inferior; instead, the GDB will
2539 stop the inferior at the point at which the exception is caught.
2540 This functionality requires a change in the exception handling
2541 code that was introduced in GCC 4.5.
2543 * GDB now follows GCC's rules on accessing volatile objects when
2544 reading or writing target state during expression evaluation.
2545 One notable difference to prior behavior is that "print x = 0"
2546 no longer generates a read of x; the value of the assignment is
2547 now always taken directly from the value being assigned.
2549 * GDB now has some support for using labels in the program's source in
2550 linespecs. For instance, you can use "advance label" to continue
2551 execution to a label.
2553 * GDB now has support for reading and writing a new .gdb_index
2554 section. This section holds a fast index of DWARF debugging
2555 information and can be used to greatly speed up GDB startup and
2556 operation. See the documentation for `save gdb-index' for details.
2558 * The "watch" command now accepts an optional "-location" argument.
2559 When used, this causes GDB to watch the memory referred to by the
2560 expression. Such a watchpoint is never deleted due to it going out
2563 * GDB now supports thread debugging of core dumps on GNU/Linux.
2565 GDB now activates thread debugging using the libthread_db library
2566 when debugging GNU/Linux core dumps, similarly to when debugging
2567 live processes. As a result, when debugging a core dump file, GDB
2568 is now able to display pthread_t ids of threads. For example, "info
2569 threads" shows the same output as when debugging the process when it
2570 was live. In earlier releases, you'd see something like this:
2573 * 1 LWP 6780 main () at main.c:10
2575 While now you see this:
2578 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2580 It is also now possible to inspect TLS variables when debugging core
2583 When debugging a core dump generated on a machine other than the one
2584 used to run GDB, you may need to point GDB at the correct
2585 libthread_db library with the "set libthread-db-search-path"
2586 command. See the user manual for more details on this command.
2588 * When natively debugging programs on PowerPC BookE processors running
2589 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2590 which stop execution of the inferior whenever it executes an instruction
2591 at any address within the specified range. See the "PowerPC Embedded"
2592 section in the user manual for more details.
2594 * New features in the GDB remote stub, GDBserver
2596 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2597 and i686 LynxOS (version 5.x).
2599 ** GDBserver is now supported on Blackfin Linux.
2601 * New native configurations
2603 ia64 HP-UX ia64-*-hpux*
2607 Analog Devices, Inc. Blackfin Processor bfin-*
2609 * Ada task switching is now supported on sparc-elf targets when
2610 debugging a program using the Ravenscar Profile. For more information,
2611 see the "Tasking Support when using the Ravenscar Profile" section
2612 in the GDB user manual.
2614 * Guile support was removed.
2616 * New features in the GNU simulator
2618 ** The --map-info flag lists all known core mappings.
2620 ** CFI flashes may be simulated via the "cfi" device.
2622 *** Changes in GDB 7.2
2624 * Shared library support for remote targets by default
2626 When GDB is configured for a generic, non-OS specific target, like
2627 for example, --target=arm-eabi or one of the many *-*-elf targets,
2628 GDB now queries remote stubs for loaded shared libraries using the
2629 `qXfer:libraries:read' packet. Previously, shared library support
2630 was always disabled for such configurations.
2634 ** Argument Dependent Lookup (ADL)
2636 In C++ ADL lookup directs function search to the namespaces of its
2637 arguments even if the namespace has not been imported.
2647 Here the compiler will search for `foo' in the namespace of 'b'
2648 and find A::foo. GDB now supports this. This construct is commonly
2649 used in the Standard Template Library for operators.
2651 ** Improved User Defined Operator Support
2653 In addition to member operators, GDB now supports lookup of operators
2654 defined in a namespace and imported with a `using' directive, operators
2655 defined in the global scope, operators imported implicitly from an
2656 anonymous namespace, and the ADL operators mentioned in the previous
2658 GDB now also supports proper overload resolution for all the previously
2659 mentioned flavors of operators.
2661 ** static const class members
2663 Printing of static const class members that are initialized in the
2664 class definition has been fixed.
2666 * Windows Thread Information Block access.
2668 On Windows targets, GDB now supports displaying the Windows Thread
2669 Information Block (TIB) structure. This structure is visible either
2670 by using the new command `info w32 thread-information-block' or, by
2671 dereferencing the new convenience variable named `$_tlb', a
2672 thread-specific pointer to the TIB. This feature is also supported
2673 when remote debugging using GDBserver.
2675 * Static tracepoints
2677 Static tracepoints are calls in the user program into a tracing
2678 library. One such library is a port of the LTTng kernel tracer to
2679 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2680 When debugging with GDBserver, GDB now supports combining the GDB
2681 tracepoint machinery with such libraries. For example: the user can
2682 use GDB to probe a static tracepoint marker (a call from the user
2683 program into the tracing library) with the new "strace" command (see
2684 "New commands" below). This creates a "static tracepoint" in the
2685 breakpoint list, that can be manipulated with the same feature set
2686 as fast and regular tracepoints. E.g., collect registers, local and
2687 global variables, collect trace state variables, and define
2688 tracepoint conditions. In addition, the user can collect extra
2689 static tracepoint marker specific data, by collecting the new
2690 $_sdata internal variable. When analyzing the trace buffer, you can
2691 inspect $_sdata like any other variable available to GDB. For more
2692 information, see the "Tracepoints" chapter in GDB user manual. New
2693 remote packets have been defined to support static tracepoints, see
2694 the "New remote packets" section below.
2696 * Better reconstruction of tracepoints after disconnected tracing
2698 GDB will attempt to download the original source form of tracepoint
2699 definitions when starting a trace run, and then will upload these
2700 upon reconnection to the target, resulting in a more accurate
2701 reconstruction of the tracepoints that are in use on the target.
2705 You can now exercise direct control over the ways that GDB can
2706 affect your program. For instance, you can disallow the setting of
2707 breakpoints, so that the program can run continuously (assuming
2708 non-stop mode). In addition, the "observer" variable is available
2709 to switch all of the different controls; in observer mode, GDB
2710 cannot affect the target's behavior at all, which is useful for
2711 tasks like diagnosing live systems in the field.
2713 * The new convenience variable $_thread holds the number of the
2716 * New remote packets
2720 Return the address of the Windows Thread Information Block of a given thread.
2724 In response to several of the tracepoint packets, the target may now
2725 also respond with a number of intermediate `qRelocInsn' request
2726 packets before the final result packet, to have GDB handle
2727 relocating an instruction to execute at a different address. This
2728 is particularly useful for stubs that support fast tracepoints. GDB
2729 reports support for this feature in the qSupported packet.
2733 List static tracepoint markers in the target program.
2737 List static tracepoint markers at a given address in the target
2740 qXfer:statictrace:read
2742 Read the static trace data collected (by a `collect $_sdata'
2743 tracepoint action). The remote stub reports support for this packet
2744 to gdb's qSupported query.
2748 Send the current settings of GDB's permission flags.
2752 Send part of the source (textual) form of a tracepoint definition,
2753 which includes location, conditional, and action list.
2755 * The source command now accepts a -s option to force searching for the
2756 script in the source search path even if the script name specifies
2759 * New features in the GDB remote stub, GDBserver
2761 - GDBserver now support tracepoints (including fast tracepoints, and
2762 static tracepoints). The feature is currently supported by the
2763 i386-linux and amd64-linux builds. See the "Tracepoints support
2764 in gdbserver" section in the manual for more information.
2766 GDBserver JIT compiles the tracepoint's conditional agent
2767 expression bytecode into native code whenever possible for low
2768 overhead dynamic tracepoints conditionals. For such tracepoints,
2769 an expression that examines program state is evaluated when the
2770 tracepoint is reached, in order to determine whether to capture
2771 trace data. If the condition is simple and false, processing the
2772 tracepoint finishes very quickly and no data is gathered.
2774 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2775 for static tracepoints support.
2777 - GDBserver now supports x86_64 Windows 64-bit debugging.
2779 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2780 it understands register description.
2782 * The --batch flag now disables pagination and queries.
2784 * X86 general purpose registers
2786 GDB now supports reading/writing byte, word and double-word x86
2787 general purpose registers directly. This means you can use, say,
2788 $ah or $ax to refer, respectively, to the byte register AH and
2789 16-bit word register AX that are actually portions of the 32-bit
2790 register EAX or 64-bit register RAX.
2792 * The `commands' command now accepts a range of breakpoints to modify.
2793 A plain `commands' following a command that creates multiple
2794 breakpoints affects all the breakpoints set by that command. This
2795 applies to breakpoints set by `rbreak', and also applies when a
2796 single `break' command creates multiple breakpoints (e.g.,
2797 breakpoints on overloaded c++ functions).
2799 * The `rbreak' command now accepts a filename specification as part of
2800 its argument, limiting the functions selected by the regex to those
2801 in the specified file.
2803 * Support for remote debugging Windows and SymbianOS shared libraries
2804 from Unix hosts has been improved. Non Windows GDB builds now can
2805 understand target reported file names that follow MS-DOS based file
2806 system semantics, such as file names that include drive letters and
2807 use the backslash character as directory separator. This makes it
2808 possible to transparently use the "set sysroot" and "set
2809 solib-search-path" on Unix hosts to point as host copies of the
2810 target's shared libraries. See the new command "set
2811 target-file-system-kind" described below, and the "Commands to
2812 specify files" section in the user manual for more information.
2816 eval template, expressions...
2817 Convert the values of one or more expressions under the control
2818 of the string template to a command line, and call it.
2820 set target-file-system-kind unix|dos-based|auto
2821 show target-file-system-kind
2822 Set or show the assumed file system kind for target reported file
2825 save breakpoints <filename>
2826 Save all current breakpoint definitions to a file suitable for use
2827 in a later debugging session. To read the saved breakpoint
2828 definitions, use the `source' command.
2830 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2833 info static-tracepoint-markers
2834 Display information about static tracepoint markers in the target.
2836 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2837 Define a static tracepoint by probing a marker at the given
2838 function, line, address, or marker ID.
2842 Enable and disable observer mode.
2844 set may-write-registers on|off
2845 set may-write-memory on|off
2846 set may-insert-breakpoints on|off
2847 set may-insert-tracepoints on|off
2848 set may-insert-fast-tracepoints on|off
2849 set may-interrupt on|off
2850 Set individual permissions for GDB effects on the target. Note that
2851 some of these settings can have undesirable or surprising
2852 consequences, particularly when changed in the middle of a session.
2853 For instance, disabling the writing of memory can prevent
2854 breakpoints from being inserted, cause single-stepping to fail, or
2855 even crash your program, if you disable after breakpoints have been
2856 inserted. However, GDB should not crash.
2858 set record memory-query on|off
2859 show record memory-query
2860 Control whether to stop the inferior if memory changes caused
2861 by an instruction cannot be recorded.
2866 The disassemble command now supports "start,+length" form of two arguments.
2870 ** GDB now provides a new directory location, called the python directory,
2871 where Python scripts written for GDB can be installed. The location
2872 of that directory is <data-directory>/python, where <data-directory>
2873 is the GDB data directory. For more details, see section `Scripting
2874 GDB using Python' in the manual.
2876 ** The GDB Python API now has access to breakpoints, symbols, symbol
2877 tables, program spaces, inferiors, threads and frame's code blocks.
2878 Additionally, GDB Parameters can now be created from the API, and
2879 manipulated via set/show in the CLI.
2881 ** New functions gdb.target_charset, gdb.target_wide_charset,
2882 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2884 ** New exception gdb.GdbError.
2886 ** Pretty-printers are now also looked up in the current program space.
2888 ** Pretty-printers can now be individually enabled and disabled.
2890 ** GDB now looks for names of Python scripts to auto-load in a
2891 special section named `.debug_gdb_scripts', in addition to looking
2892 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2894 * Tracepoint actions were unified with breakpoint commands. In particular,
2895 there are no longer differences in "info break" output for breakpoints and
2896 tracepoints and the "commands" command can be used for both tracepoints and
2897 regular breakpoints.
2901 ARM Symbian arm*-*-symbianelf*
2903 * D language support.
2904 GDB now supports debugging programs written in the D programming
2907 * GDB now supports the extended ptrace interface for PowerPC which is
2908 available since Linux kernel version 2.6.34. This automatically enables
2909 any hardware breakpoints and additional hardware watchpoints available in
2910 the processor. The old ptrace interface exposes just one hardware
2911 watchpoint and no hardware breakpoints.
2913 * GDB is now able to use the Data Value Compare (DVC) register available on
2914 embedded PowerPC processors to implement in hardware simple watchpoint
2915 conditions of the form:
2917 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2919 This works in native GDB running on Linux kernels with the extended ptrace
2920 interface mentioned above.
2922 *** Changes in GDB 7.1
2926 ** Namespace Support
2928 GDB now supports importing of namespaces in C++. This enables the
2929 user to inspect variables from imported namespaces. Support for
2930 namepace aliasing has also been added. So, if a namespace is
2931 aliased in the current scope (e.g. namepace C=A; ) the user can
2932 print variables using the alias (e.g. (gdb) print C::x).
2936 All known bugs relating to the printing of virtual base class were
2937 fixed. It is now possible to call overloaded static methods using a
2942 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2943 and reinterpret_cast<> are now handled by the C++ expression parser.
2947 Xilinx MicroBlaze microblaze-*-*
2952 Xilinx MicroBlaze microblaze
2955 * Multi-program debugging.
2957 GDB now has support for multi-program (a.k.a. multi-executable or
2958 multi-exec) debugging. This allows for debugging multiple inferiors
2959 simultaneously each running a different program under the same GDB
2960 session. See "Debugging Multiple Inferiors and Programs" in the
2961 manual for more information. This implied some user visible changes
2962 in the multi-inferior support. For example, "info inferiors" now
2963 lists inferiors that are not running yet or that have exited
2964 already. See also "New commands" and "New options" below.
2966 * New tracing features
2968 GDB's tracepoint facility now includes several new features:
2970 ** Trace state variables
2972 GDB tracepoints now include support for trace state variables, which
2973 are variables managed by the target agent during a tracing
2974 experiment. They are useful for tracepoints that trigger each
2975 other, so for instance one tracepoint can count hits in a variable,
2976 and then a second tracepoint has a condition that is true when the
2977 count reaches a particular value. Trace state variables share the
2978 $-syntax of GDB convenience variables, and can appear in both
2979 tracepoint actions and condition expressions. Use the "tvariable"
2980 command to create, and "info tvariables" to view; see "Trace State
2981 Variables" in the manual for more detail.
2985 GDB now includes an option for defining fast tracepoints, which
2986 targets may implement more efficiently, such as by installing a jump
2987 into the target agent rather than a trap instruction. The resulting
2988 speedup can be by two orders of magnitude or more, although the
2989 tradeoff is that some program locations on some target architectures
2990 might not allow fast tracepoint installation, for instance if the
2991 instruction to be replaced is shorter than the jump. To request a
2992 fast tracepoint, use the "ftrace" command, with syntax identical to
2993 the regular trace command.
2995 ** Disconnected tracing
2997 It is now possible to detach GDB from the target while it is running
2998 a trace experiment, then reconnect later to see how the experiment
2999 is going. In addition, a new variable disconnected-tracing lets you
3000 tell the target agent whether to continue running a trace if the
3001 connection is lost unexpectedly.
3005 GDB now has the ability to save the trace buffer into a file, and
3006 then use that file as a target, similarly to you can do with
3007 corefiles. You can select trace frames, print data that was
3008 collected in them, and use tstatus to display the state of the
3009 tracing run at the moment that it was saved. To create a trace
3010 file, use "tsave <filename>", and to use it, do "target tfile
3013 ** Circular trace buffer
3015 You can ask the target agent to handle the trace buffer as a
3016 circular buffer, discarding the oldest trace frames to make room for
3017 newer ones, by setting circular-trace-buffer to on. This feature may
3018 not be available for all target agents.
3023 The disassemble command, when invoked with two arguments, now requires
3024 the arguments to be comma-separated.
3027 The info variables command now displays variable definitions. Files
3028 which only declare a variable are not shown.
3031 The source command is now capable of sourcing Python scripts.
3032 This feature is dependent on the debugger being build with Python
3035 Related to this enhancement is also the introduction of a new command
3036 "set script-extension" (see below).
3038 * New commands (for set/show, see "New options" below)
3040 record save [<FILENAME>]
3041 Save a file (in core file format) containing the process record
3042 execution log for replay debugging at a later time.
3044 record restore <FILENAME>
3045 Restore the process record execution log that was saved at an
3046 earlier time, for replay debugging.
3048 add-inferior [-copies <N>] [-exec <FILENAME>]
3051 clone-inferior [-copies <N>] [ID]
3052 Make a new inferior ready to execute the same program another
3053 inferior has loaded.
3058 maint info program-spaces
3059 List the program spaces loaded into GDB.
3061 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3062 show remote interrupt-sequence
3063 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3064 as the sequence to the remote target in order to interrupt the execution.
3065 Ctrl-C is a default. Some system prefers BREAK which is high level of
3066 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3067 Magic SysRq g. It is BREAK signal and character 'g'.
3069 set remote interrupt-on-connect [on | off]
3070 show remote interrupt-on-connect
3071 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3072 remote target when gdb connects to it. This is needed when you debug
3075 set remotebreak [on | off]
3077 Deprecated. Use "set/show remote interrupt-sequence" instead.
3079 tvariable $NAME [ = EXP ]
3080 Create or modify a trace state variable.
3083 List trace state variables and their values.
3085 delete tvariable $NAME ...
3086 Delete one or more trace state variables.
3089 Evaluate the given expressions without collecting anything into the
3090 trace buffer. (Valid in tracepoint actions only.)
3092 ftrace FN / FILE:LINE / *ADDR
3093 Define a fast tracepoint at the given function, line, or address.
3095 * New expression syntax
3097 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3098 GDB now parses 0b101010 identically with 42.
3102 set follow-exec-mode new|same
3103 show follow-exec-mode
3104 Control whether GDB reuses the same inferior across an exec call or
3105 creates a new one. This is useful to be able to restart the old
3106 executable after the inferior having done an exec call.
3108 set default-collect EXPR, ...
3109 show default-collect
3110 Define a list of expressions to be collected at each tracepoint.
3111 This is a useful way to ensure essential items are not overlooked,
3112 such as registers or a critical global variable.
3114 set disconnected-tracing
3115 show disconnected-tracing
3116 If set to 1, the target is instructed to continue tracing if it
3117 loses its connection to GDB. If 0, the target is to stop tracing
3120 set circular-trace-buffer
3121 show circular-trace-buffer
3122 If set to on, the target is instructed to use a circular trace buffer
3123 and discard the oldest trace frames instead of stopping the trace due
3124 to a full trace buffer. If set to off, the trace stops when the buffer
3125 fills up. Some targets may not support this.
3127 set script-extension off|soft|strict
3128 show script-extension
3129 If set to "off", the debugger does not perform any script language
3130 recognition, and all sourced files are assumed to be GDB scripts.
3131 If set to "soft" (the default), files are sourced according to
3132 filename extension, falling back to GDB scripts if the first
3134 If set to "strict", files are sourced according to filename extension.
3136 set ada trust-PAD-over-XVS on|off
3137 show ada trust-PAD-over-XVS
3138 If off, activate a workaround against a bug in the debugging information
3139 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3140 the GCC sources for more information about the GNAT encoding and
3141 PAD types in particular). It is always safe to set this option to
3142 off, but this introduces a slight performance penalty. The default
3145 * Python API Improvements
3147 ** GDB provides the new class gdb.LazyString. This is useful in
3148 some pretty-printing cases. The new method gdb.Value.lazy_string
3149 provides a simple way to create objects of this type.
3151 ** The fields returned by gdb.Type.fields now have an
3152 `is_base_class' attribute.
3154 ** The new method gdb.Type.range returns the range of an array type.
3156 ** The new method gdb.parse_and_eval can be used to parse and
3157 evaluate an expression.
3159 * New remote packets
3162 Define a trace state variable.
3165 Get the current value of a trace state variable.
3168 Set desired tracing behavior upon disconnection.
3171 Set the trace buffer to be linear or circular.
3174 Get data about the tracepoints currently in use.
3178 Process record now works correctly with hardware watchpoints.
3180 Multiple bug fixes have been made to the mips-irix port, making it
3181 much more reliable. In particular:
3182 - Debugging threaded applications is now possible again. Previously,
3183 GDB would hang while starting the program, or while waiting for
3184 the program to stop at a breakpoint.
3185 - Attaching to a running process no longer hangs.
3186 - An error occurring while loading a core file has been fixed.
3187 - Changing the value of the PC register now works again. This fixes
3188 problems observed when using the "jump" command, or when calling
3189 a function from GDB, or even when assigning a new value to $pc.
3190 - With the "finish" and "return" commands, the return value for functions
3191 returning a small array is now correctly printed.
3192 - It is now possible to break on shared library code which gets executed
3193 during a shared library init phase (code executed while executing
3194 their .init section). Previously, the breakpoint would have no effect.
3195 - GDB is now able to backtrace through the signal handler for
3196 non-threaded programs.
3198 PIE (Position Independent Executable) programs debugging is now supported.
3199 This includes debugging execution of PIC (Position Independent Code) shared
3200 libraries although for that, it should be possible to run such libraries as an
3203 *** Changes in GDB 7.0
3205 * GDB now has an interface for JIT compilation. Applications that
3206 dynamically generate code can create symbol files in memory and register
3207 them with GDB. For users, the feature should work transparently, and
3208 for JIT developers, the interface is documented in the GDB manual in the
3209 "JIT Compilation Interface" chapter.
3211 * Tracepoints may now be conditional. The syntax is as for
3212 breakpoints; either an "if" clause appended to the "trace" command,
3213 or the "condition" command is available. GDB sends the condition to
3214 the target for evaluation using the same bytecode format as is used
3215 for tracepoint actions.
3217 * The disassemble command now supports: an optional /r modifier, print the
3218 raw instructions in hex as well as in symbolic form, and an optional /m
3219 modifier to print mixed source+assembly.
3221 * Process record and replay
3223 In a architecture environment that supports ``process record and
3224 replay'', ``process record and replay'' target can record a log of
3225 the process execution, and replay it with both forward and reverse
3228 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3229 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3230 set execution-direction {forward|reverse}, for targets that support
3233 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3234 feature is available with a native GDB running on kernel version
3237 * GDB now has support for multi-byte and wide character sets on the
3238 target. Strings whose character type is wchar_t, char16_t, or
3239 char32_t are now correctly printed. GDB supports wide- and unicode-
3240 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3241 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3242 `printf'. This feature requires iconv to work properly; if your
3243 system does not have a working iconv, GDB can use GNU libiconv. See
3244 the installation instructions for more information.
3246 * GDB now supports automatic retrieval of shared library files from
3247 remote targets. To use this feature, specify a system root that begins
3248 with the `remote:' prefix, either via the `set sysroot' command or via
3249 the `--with-sysroot' configure-time option.
3251 * "info sharedlibrary" now takes an optional regex of libraries to show,
3252 and it now reports if a shared library has no debugging information.
3254 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3255 now complete on file names.
3257 * When completing in expressions, gdb will attempt to limit
3258 completions to allowable structure or union fields, where appropriate.
3259 For instance, consider:
3261 # struct example { int f1; double f2; };
3262 # struct example variable;
3265 If the user types TAB at the end of this command line, the available
3266 completions will be "f1" and "f2".
3268 * Inlined functions are now supported. They show up in backtraces, and
3269 the "step", "next", and "finish" commands handle them automatically.
3271 * GDB now supports the token-splicing (##) and stringification (#)
3272 operators when expanding macros. It also supports variable-arity
3275 * GDB now supports inspecting extra signal information, exported by
3276 the new $_siginfo convenience variable. The feature is currently
3277 implemented on linux ARM, i386 and amd64.
3279 * GDB can now display the VFP floating point registers and NEON vector
3280 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3281 can provide these registers (requires Linux 2.6.30 or later). Remote
3282 and simulator targets may also provide them.
3284 * New remote packets
3287 Search memory for a sequence of bytes.
3290 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3291 operation over reliable transport links. Use of this packet is
3292 controlled by the `set remote noack-packet' command.
3295 Kill the process with the specified process ID. Use this in preference
3296 to `k' when multiprocess protocol extensions are supported.
3299 Obtains additional operating system information
3303 Read or write additional signal information.
3305 * Removed remote protocol undocumented extension
3307 An undocumented extension to the remote protocol's `S' stop reply
3308 packet that permited the stub to pass a process id was removed.
3309 Remote servers should use the `T' stop reply packet instead.
3311 * GDB now supports multiple function calling conventions according to the
3312 DWARF-2 DW_AT_calling_convention function attribute.
3314 * The SH target utilizes the aforementioned change to distinguish between gcc
3315 and Renesas calling convention. It also adds the new CLI commands
3316 `set/show sh calling-convention'.
3318 * GDB can now read compressed debug sections, as produced by GNU gold
3319 with the --compress-debug-sections=zlib flag.
3321 * 64-bit core files are now supported on AIX.
3323 * Thread switching is now supported on Tru64.
3325 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3326 which will be allocated using malloc later in program execution.
3328 * The qXfer:libraries:read remote procotol packet now allows passing a
3329 list of section offsets.
3331 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3332 conditions handling signals delivered during attach or thread creation
3333 have also been fixed.
3335 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3336 From the user's standpoint, all unqualified instances of True and False
3337 are treated as the standard definitions, regardless of context.
3339 * GDB now parses C++ symbol and type names more flexibly. For
3342 template<typename T> class C { };
3345 GDB will now correctly handle all of:
3347 ptype C<char const *>
3348 ptype C<char const*>
3349 ptype C<const char *>
3350 ptype C<const char*>
3352 * New features in the GDB remote stub, gdbserver
3354 - The "--wrapper" command-line argument tells gdbserver to use a
3355 wrapper program to launch programs for debugging.
3357 - On PowerPC and S/390 targets, it is now possible to use a single
3358 gdbserver executable to debug both 32-bit and 64-bit programs.
3359 (This requires gdbserver itself to be built as a 64-bit executable.)
3361 - gdbserver uses the new noack protocol mode for TCP connections to
3362 reduce communications latency, if also supported and enabled in GDB.
3364 - Support for the sparc64-linux-gnu target is now included in
3367 - The amd64-linux build of gdbserver now supports debugging both
3368 32-bit and 64-bit programs.
3370 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3371 now support hardware watchpoints, and will use them automatically
3376 GDB now has support for scripting using Python. Whether this is
3377 available is determined at configure time.
3379 New GDB commands can now be written in Python.
3381 * Ada tasking support
3383 Ada tasks can now be inspected in GDB. The following commands have
3387 Print the list of Ada tasks.
3389 Print detailed information about task number N.
3391 Print the task number of the current task.
3393 Switch the context of debugging to task number N.
3395 * Support for user-defined prefixed commands. The "define" command can
3396 add new commands to existing prefixes, e.g. "target".
3398 * Multi-inferior, multi-process debugging.
3400 GDB now has generalized support for multi-inferior debugging. See
3401 "Debugging Multiple Inferiors" in the manual for more information.
3402 Although availability still depends on target support, the command
3403 set is more uniform now. The GNU/Linux specific multi-forks support
3404 has been migrated to this new framework. This implied some user
3405 visible changes; see "New commands" and also "Removed commands"
3408 * Target descriptions can now describe the target OS ABI. See the
3409 "Target Description Format" section in the user manual for more
3412 * Target descriptions can now describe "compatible" architectures
3413 to indicate that the target can execute applications for a different
3414 architecture in addition to those for the main target architecture.
3415 See the "Target Description Format" section in the user manual for
3418 * Multi-architecture debugging.
3420 GDB now includes general supports for debugging applications on
3421 hybrid systems that use more than one single processor architecture
3422 at the same time. Each such hybrid architecture still requires
3423 specific support to be added. The only hybrid architecture supported
3424 in this version of GDB is the Cell Broadband Engine.
3426 * GDB now supports integrated debugging of Cell/B.E. applications that
3427 use both the PPU and SPU architectures. To enable support for hybrid
3428 Cell/B.E. debugging, you need to configure GDB to support both the
3429 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3430 --enable-targets configure option.
3432 * Non-stop mode debugging.
3434 For some targets, GDB now supports an optional mode of operation in
3435 which you can examine stopped threads while other threads continue
3436 to execute freely. This is referred to as non-stop mode, with the
3437 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3438 section in the user manual for more information.
3440 To be able to support remote non-stop debugging, a remote stub needs
3441 to implement the non-stop mode remote protocol extensions, as
3442 described in the "Remote Non-Stop" section of the user manual. The
3443 GDB remote stub, gdbserver, has been adjusted to support these
3444 extensions on linux targets.
3446 * New commands (for set/show, see "New options" below)
3448 catch syscall [NAME(S) | NUMBER(S)]
3449 Catch system calls. Arguments, which should be names of system
3450 calls or their numbers, mean catch only those syscalls. Without
3451 arguments, every syscall will be caught. When the inferior issues
3452 any of the specified syscalls, GDB will stop and announce the system
3453 call, both when it is called and when its call returns. This
3454 feature is currently available with a native GDB running on the
3455 Linux Kernel, under the following architectures: x86, x86_64,
3456 PowerPC and PowerPC64.
3458 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3460 Search memory for a sequence of bytes.
3462 maint set python print-stack
3463 maint show python print-stack
3464 Show a stack trace when an error is encountered in a Python script.
3467 Invoke CODE by passing it to the Python interpreter.
3472 These allow macros to be defined, undefined, and listed
3476 Show operating system information about processes.
3479 List the inferiors currently under GDB's control.
3482 Switch focus to inferior number NUM.
3485 Detach from inferior number NUM.
3488 Kill inferior number NUM.
3492 set spu stop-on-load
3493 show spu stop-on-load
3494 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3496 set spu auto-flush-cache
3497 show spu auto-flush-cache
3498 Control whether to automatically flush the software-managed cache
3499 during Cell/B.E. debugging.
3501 set sh calling-convention
3502 show sh calling-convention
3503 Control the calling convention used when calling SH target functions.
3506 show debug timestamp
3507 Control display of timestamps with GDB debugging output.
3509 set disassemble-next-line
3510 show disassemble-next-line
3511 Control display of disassembled source lines or instructions when
3514 set remote noack-packet
3515 show remote noack-packet
3516 Set/show the use of remote protocol QStartNoAckMode packet. See above
3517 under "New remote packets."
3519 set remote query-attached-packet
3520 show remote query-attached-packet
3521 Control use of remote protocol `qAttached' (query-attached) packet.
3523 set remote read-siginfo-object
3524 show remote read-siginfo-object
3525 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3528 set remote write-siginfo-object
3529 show remote write-siginfo-object
3530 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3533 set remote reverse-continue
3534 show remote reverse-continue
3535 Control use of remote protocol 'bc' (reverse-continue) packet.
3537 set remote reverse-step
3538 show remote reverse-step
3539 Control use of remote protocol 'bs' (reverse-step) packet.
3541 set displaced-stepping
3542 show displaced-stepping
3543 Control displaced stepping mode. Displaced stepping is a way to
3544 single-step over breakpoints without removing them from the debuggee.
3545 Also known as "out-of-line single-stepping".
3548 show debug displaced
3549 Control display of debugging info for displaced stepping.
3551 maint set internal-error
3552 maint show internal-error
3553 Control what GDB does when an internal error is detected.
3555 maint set internal-warning
3556 maint show internal-warning
3557 Control what GDB does when an internal warning is detected.
3562 Use a wrapper program to launch programs for debugging.
3564 set multiple-symbols (all|ask|cancel)
3565 show multiple-symbols
3566 The value of this variable can be changed to adjust the debugger behavior
3567 when an expression or a breakpoint location contains an ambiguous symbol
3568 name (an overloaded function name, for instance).
3570 set breakpoint always-inserted
3571 show breakpoint always-inserted
3572 Keep breakpoints always inserted in the target, as opposed to inserting
3573 them when resuming the target, and removing them when the target stops.
3574 This option can improve debugger performance on slow remote targets.
3576 set arm fallback-mode (arm|thumb|auto)
3577 show arm fallback-mode
3578 set arm force-mode (arm|thumb|auto)
3580 These commands control how ARM GDB determines whether instructions
3581 are ARM or Thumb. The default for both settings is auto, which uses
3582 the current CPSR value for instructions without symbols; previous
3583 versions of GDB behaved as if "set arm fallback-mode arm".
3585 set disable-randomization
3586 show disable-randomization
3587 Standalone programs run with the virtual address space randomization enabled
3588 by default on some platforms. This option keeps the addresses stable across
3589 multiple debugging sessions.
3593 Control whether other threads are stopped or not when some thread hits
3598 Requests that asynchronous execution is enabled in the target, if available.
3599 In this case, it's possible to resume target in the background, and interact
3600 with GDB while the target is running. "show target-async" displays the
3601 current state of asynchronous execution of the target.
3603 set target-wide-charset
3604 show target-wide-charset
3605 The target-wide-charset is the name of the character set that GDB
3606 uses when printing characters whose type is wchar_t.
3608 set tcp auto-retry (on|off)
3610 set tcp connect-timeout
3611 show tcp connect-timeout
3612 These commands allow GDB to retry failed TCP connections to a remote stub
3613 with a specified timeout period; this is useful if the stub is launched
3614 in parallel with GDB but may not be ready to accept connections immediately.
3616 set libthread-db-search-path
3617 show libthread-db-search-path
3618 Control list of directories which GDB will search for appropriate
3621 set schedule-multiple (on|off)
3622 show schedule-multiple
3623 Allow GDB to resume all threads of all processes or only threads of
3624 the current process.
3628 Use more aggressive caching for accesses to the stack. This improves
3629 performance of remote debugging (particularly backtraces) without
3630 affecting correctness.
3632 set interactive-mode (on|off|auto)
3633 show interactive-mode
3634 Control whether GDB runs in interactive mode (on) or not (off).
3635 When in interactive mode, GDB waits for the user to answer all
3636 queries. Otherwise, GDB does not wait and assumes the default
3637 answer. When set to auto (the default), GDB determines which
3638 mode to use based on the stdin settings.
3643 For program forks, this is replaced by the new more generic `info
3644 inferiors' command. To list checkpoints, you can still use the
3645 `info checkpoints' command, which was an alias for the `info forks'
3649 Replaced by the new `inferior' command. To switch between
3650 checkpoints, you can still use the `restart' command, which was an
3651 alias for the `fork' command.
3654 This is removed, since some targets don't have a notion of
3655 processes. To switch between processes, you can still use the
3656 `inferior' command using GDB's own inferior number.
3659 For program forks, this is replaced by the new more generic `kill
3660 inferior' command. To delete a checkpoint, you can still use the
3661 `delete checkpoint' command, which was an alias for the `delete
3665 For program forks, this is replaced by the new more generic `detach
3666 inferior' command. To detach a checkpoint, you can still use the
3667 `detach checkpoint' command, which was an alias for the `detach
3670 * New native configurations
3672 x86/x86_64 Darwin i[34567]86-*-darwin*
3674 x86_64 MinGW x86_64-*-mingw*
3678 Lattice Mico32 lm32-*
3679 x86 DICOS i[34567]86-*-dicos*
3680 x86_64 DICOS x86_64-*-dicos*
3683 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3684 (mingw32ce) debugging.
3690 These commands were actually not implemented on any target.
3692 *** Changes in GDB 6.8
3694 * New native configurations
3696 NetBSD/hppa hppa*-*netbsd*
3697 Xtensa GNU/Linux xtensa*-*-linux*
3701 NetBSD/hppa hppa*-*-netbsd*
3702 Xtensa GNU/Lunux xtensa*-*-linux*
3704 * Change in command line behavior -- corefiles vs. process ids.
3706 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3707 attaching to process NUMBER fails, GDB no longer attempts to open a
3708 core file named NUMBER. Attaching to a program using the -c option
3709 is no longer supported. Instead, use the '-p' or '--pid' options.
3711 * GDB can now be built as a native debugger for debugging Windows x86
3712 (mingw32) Portable Executable (PE) programs.
3714 * Pending breakpoints no longer change their number when their address
3717 * GDB now supports breakpoints with multiple locations,
3718 including breakpoints on C++ constructors, inside C++ templates,
3719 and in inlined functions.
3721 * GDB's ability to debug optimized code has been improved. GDB more
3722 accurately identifies function bodies and lexical blocks that occupy
3723 more than one contiguous range of addresses.
3725 * Target descriptions can now describe registers for PowerPC.
3727 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3728 registers on PowerPC targets.
3730 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3731 targets even when the libthread_db library is not available.
3733 * The GDB remote stub, gdbserver, now supports the new file transfer
3734 commands (remote put, remote get, and remote delete).
3736 * The GDB remote stub, gdbserver, now supports run and attach in
3737 extended-remote mode.
3739 * hppa*64*-*-hpux11* target broken
3740 The debugger is unable to start a program and fails with the following
3741 error: "Error trying to get information about dynamic linker".
3742 The gdb-6.7 release is also affected.
3744 * GDB now supports the --enable-targets= configure option to allow
3745 building a single GDB executable that supports multiple remote
3746 target architectures.
3748 * GDB now supports debugging C and C++ programs which use the
3749 Decimal Floating Point extension. In addition, the PowerPC target
3750 now has a set of pseudo-registers to inspect decimal float values
3751 stored in two consecutive float registers.
3753 * The -break-insert MI command can optionally create pending
3756 * Improved support for debugging Ada
3757 Many improvements to the Ada language support have been made. These
3759 - Better support for Ada2005 interface types
3760 - Improved handling of arrays and slices in general
3761 - Better support for Taft-amendment types
3762 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3764 - Improved command completion in Ada
3767 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3772 set print frame-arguments (all|scalars|none)
3773 show print frame-arguments
3774 The value of this variable can be changed to control which argument
3775 values should be printed by the debugger when displaying a frame.
3780 Transfer files to and from a remote target, and delete remote files.
3787 Transfer files to and from a remote target, and delete remote files.
3789 * New remote packets
3796 Open, close, read, write, and delete files on the remote system.
3799 Attach to an existing process on the remote system, in extended-remote
3803 Run a new process on the remote system, in extended-remote mode.
3805 *** Changes in GDB 6.7
3807 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3808 bfd, libiberty and opcodes, as revealed by static analysis donated by
3809 Coverity, Inc. (http://scan.coverity.com).
3811 * When looking up multiply-defined global symbols, GDB will now prefer the
3812 symbol definition in the current shared library if it was built using the
3813 -Bsymbolic linker option.
3815 * When the Text User Interface (TUI) is not configured, GDB will now
3816 recognize the -tui command-line option and print a message that the TUI
3819 * The GDB remote stub, gdbserver, now has lower overhead for high
3820 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3822 * GDB for MIPS targets now autodetects whether a remote target provides
3823 32-bit or 64-bit register values.
3825 * Support for C++ member pointers has been improved.
3827 * GDB now understands XML target descriptions, which specify the
3828 target's overall architecture. GDB can read a description from
3829 a local file or over the remote serial protocol.
3831 * Vectors of single-byte data use a new integer type which is not
3832 automatically displayed as character or string data.
3834 * The /s format now works with the print command. It displays
3835 arrays of single-byte integers and pointers to single-byte integers
3838 * Target descriptions can now describe target-specific registers,
3839 for architectures which have implemented the support (currently
3840 only ARM, M68K, and MIPS).
3842 * GDB and the GDB remote stub, gdbserver, now support the XScale
3845 * The GDB remote stub, gdbserver, has been updated to support
3846 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3847 has been rewritten to use the standard GDB remote protocol.
3849 * GDB can now step into C++ functions which are called through thunks.
3851 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3853 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3854 layout. It also supports a TextSeg= and DataSeg= response when only
3855 segment base addresses (rather than offsets) are available.
3857 * The /i format now outputs any trailing branch delay slot instructions
3858 immediately following the last instruction within the count specified.
3860 * The GDB remote protocol "T" stop reply packet now supports a
3861 "library" response. Combined with the new "qXfer:libraries:read"
3862 packet, this response allows GDB to debug shared libraries on targets
3863 where the operating system manages the list of loaded libraries (e.g.
3864 Windows and SymbianOS).
3866 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3867 (DLLs) on Windows and Windows CE targets.
3869 * GDB now supports a faster verification that a .debug file matches its binary
3870 according to its build-id signature, if the signature is present.
3876 Enable or disable hardware flow control (RTS/CTS) on the serial port
3877 when debugging using remote targets.
3879 set mem inaccessible-by-default
3880 show mem inaccessible-by-default
3881 If the target supplies a memory map, for instance via the remote
3882 protocol's "qXfer:memory-map:read" packet, setting this variable
3883 prevents GDB from accessing memory outside the memory map. This
3884 is useful for targets with memory mapped registers or which react
3885 badly to accesses of unmapped address space.
3887 set breakpoint auto-hw
3888 show breakpoint auto-hw
3889 If the target supplies a memory map, for instance via the remote
3890 protocol's "qXfer:memory-map:read" packet, setting this variable
3891 lets GDB use hardware breakpoints automatically for memory regions
3892 where it can not use software breakpoints. This covers both the
3893 "break" command and internal breakpoints used for other commands
3894 including "next" and "finish".
3897 catch exception unhandled
3898 Stop the program execution when Ada exceptions are raised.
3901 Stop the program execution when an Ada assertion failed.
3905 Set an alternate system root for target files. This is a more
3906 general version of "set solib-absolute-prefix", which is now
3907 an alias to "set sysroot".
3910 Provide extended SPU facility status information. This set of
3911 commands is available only when debugging the Cell/B.E. SPU
3914 * New native configurations
3916 OpenBSD/sh sh*-*openbsd*
3919 unset tdesc filename
3921 Use the specified local file as an XML target description, and do
3922 not query the target for its built-in description.
3926 OpenBSD/sh sh*-*-openbsd*
3927 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3928 Toshiba Media Processor mep-elf
3930 * New remote packets
3933 Ignore the specified signals; pass them directly to the debugged program
3934 without stopping other threads or reporting them to GDB.
3936 qXfer:features:read:
3937 Read an XML target description from the target, which describes its
3942 Read or write contents of an spufs file on the target system. These
3943 packets are available only on the Cell/B.E. SPU architecture.
3945 qXfer:libraries:read:
3946 Report the loaded shared libraries. Combined with new "T" packet
3947 response, this packet allows GDB to debug shared libraries on
3948 targets where the operating system manages the list of loaded
3949 libraries (e.g. Windows and SymbianOS).
3953 Support for these obsolete configurations has been removed.
3961 i[34567]86-*-lynxos*
3962 i[34567]86-*-netware*
3963 i[34567]86-*-sco3.2v5*
3964 i[34567]86-*-sco3.2v4*
3966 i[34567]86-*-sysv4.2*
3969 i[34567]86-*-unixware2*
3970 i[34567]86-*-unixware*
3979 * Other removed features
3986 Various m68k-only ROM monitors.
3993 Various Renesas ROM monitors and debugging interfaces for SH and
3998 Support for a Macraigor serial interface to on-chip debugging.
3999 GDB does not directly support the newer parallel or USB
4004 A debug information format. The predecessor to DWARF 2 and
4005 DWARF 3, which are still supported.
4007 Support for the HP aCC compiler on HP-UX/PA-RISC
4009 SOM-encapsulated symbolic debugging information, automatic
4010 invocation of pxdb, and the aCC custom C++ ABI. This does not
4011 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4012 with aCC can still be debugged on an assembly level.
4014 MIPS ".pdr" sections
4016 A MIPS-specific format used to describe stack frame layout
4017 in debugging information.
4021 GDB could work with an older version of Guile to debug
4022 the interpreter and Scheme programs running in it.
4024 set mips stack-arg-size
4025 set mips saved-gpreg-size
4027 Use "set mips abi" to control parameter passing for MIPS.
4029 *** Changes in GDB 6.6
4034 Cell Broadband Engine SPU spu-elf
4036 * GDB can now be configured as a cross-debugger targeting native Windows
4037 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4038 running on a Windows system over TCP/IP to debug Windows programs.
4040 * The GDB remote stub, gdbserver, has been updated to support Windows and
4041 Cygwin debugging. Both single-threaded and multi-threaded programs are
4044 * The "set trust-readonly-sections" command works again. This command was
4045 broken in GDB 6.3, 6.4, and 6.5.
4047 * The "load" command now supports writing to flash memory, if the remote
4048 stub provides the required support.
4050 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4051 longer requires symbolic debug information (e.g. DWARF-2).
4056 unset substitute-path
4057 show substitute-path
4058 Manage a list of substitution rules that GDB uses to rewrite the name
4059 of the directories where the sources are located. This can be useful
4060 for instance when the sources were moved to a different location
4061 between compilation and debugging.
4065 Print each CLI command as it is executed. Each command is prefixed with
4066 a number of `+' symbols representing the nesting depth.
4067 The source command now has a `-v' option to enable the same feature.
4071 The ARM Demon monitor support (RDP protocol, "target rdp").
4073 Kernel Object Display, an embedded debugging feature which only worked with
4074 an obsolete version of Cisco IOS.
4076 The 'set download-write-size' and 'show download-write-size' commands.
4078 * New remote packets
4081 Tell a stub about GDB client features, and request remote target features.
4082 The first feature implemented is PacketSize, which allows the target to
4083 specify the size of packets it can handle - to minimize the number of
4084 packets required and improve performance when connected to a remote
4088 Fetch an OS auxilliary vector from the remote stub. This packet is a
4089 more efficient replacement for qPart:auxv:read.
4091 qXfer:memory-map:read:
4092 Fetch a memory map from the remote stub, including information about
4093 RAM, ROM, and flash memory devices.
4098 Erase and program a flash memory device.
4100 * Removed remote packets
4103 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4104 used it, and only gdbserver implemented it.
4106 *** Changes in GDB 6.5
4110 Renesas M32C/M16C m32c-elf
4112 Morpho Technologies ms1 ms1-elf
4116 init-if-undefined Initialize a convenience variable, but
4117 only if it doesn't already have a value.
4119 The following commands are presently only implemented for native GNU/Linux:
4121 checkpoint Save a snapshot of the program state.
4123 restart <n> Return the program state to a
4124 previously saved state.
4126 info checkpoints List currently saved checkpoints.
4128 delete-checkpoint <n> Delete a previously saved checkpoint.
4130 set|show detach-on-fork Tell gdb whether to detach from a newly
4131 forked process, or to keep debugging it.
4133 info forks List forks of the user program that
4134 are available to be debugged.
4136 fork <n> Switch to debugging one of several
4137 forks of the user program that are
4138 available to be debugged.
4140 delete-fork <n> Delete a fork from the list of forks
4141 that are available to be debugged (and
4142 kill the forked process).
4144 detach-fork <n> Delete a fork from the list of forks
4145 that are available to be debugged (and
4146 allow the process to continue).
4150 Morpho Technologies ms2 ms1-elf
4152 * Improved Windows host support
4154 GDB now builds as a cross debugger hosted on i686-mingw32, including
4155 native console support, and remote communications using either
4156 network sockets or serial ports.
4158 * Improved Modula-2 language support
4160 GDB can now print most types in the Modula-2 syntax. This includes:
4161 basic types, set types, record types, enumerated types, range types,
4162 pointer types and ARRAY types. Procedure var parameters are correctly
4163 printed and hexadecimal addresses and character constants are also
4164 written in the Modula-2 syntax. Best results can be obtained by using
4165 GNU Modula-2 together with the -gdwarf-2 command line option.
4169 The ARM rdi-share module.
4171 The Netware NLM debug server.
4173 *** Changes in GDB 6.4
4175 * New native configurations
4177 OpenBSD/arm arm*-*-openbsd*
4178 OpenBSD/mips64 mips64-*-openbsd*
4182 Morpho Technologies ms1 ms1-elf
4184 * New command line options
4186 --batch-silent As for --batch, but totally silent.
4187 --return-child-result The debugger will exist with the same value
4188 the child (debugged) program exited with.
4189 --eval-command COMMAND, -ex COMMAND
4190 Execute a single GDB CLI command. This may be
4191 specified multiple times and in conjunction
4192 with the --command (-x) option.
4194 * Deprecated commands removed
4196 The following commands, that were deprecated in 2000, have been
4200 set|show arm disassembly-flavor set|show arm disassembler
4201 othernames set arm disassembler
4202 set|show remotedebug set|show debug remote
4203 set|show archdebug set|show debug arch
4204 set|show eventdebug set|show debug event
4207 * New BSD user-level threads support
4209 It is now possible to debug programs using the user-level threads
4210 library on OpenBSD and FreeBSD. Currently supported (target)
4213 FreeBSD/amd64 x86_64-*-freebsd*
4214 FreeBSD/i386 i386-*-freebsd*
4215 OpenBSD/i386 i386-*-openbsd*
4217 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4218 are not yet supported.
4220 * New support for Matsushita MN10300 w/sim added
4221 (Work in progress). mn10300-elf.
4223 * REMOVED configurations and files
4225 VxWorks and the XDR protocol *-*-vxworks
4226 Motorola MCORE mcore-*-*
4227 National Semiconductor NS32000 ns32k-*-*
4229 * New "set print array-indexes" command
4231 After turning this setting "on", GDB prints the index of each element
4232 when displaying arrays. The default is "off" to preserve the previous
4235 * VAX floating point support
4237 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4239 * User-defined command support
4241 In addition to using $arg0..$arg9 for argument passing, it is now possible
4242 to use $argc to determine now many arguments have been passed. See the
4243 section on user-defined commands in the user manual for more information.
4245 *** Changes in GDB 6.3:
4247 * New command line option
4249 GDB now accepts -l followed by a number to set the timeout for remote
4252 * GDB works with GCC -feliminate-dwarf2-dups
4254 GDB now supports a more compact representation of DWARF-2 debug
4255 information using DW_FORM_ref_addr references. These are produced
4256 by GCC with the option -feliminate-dwarf2-dups and also by some
4257 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4258 to use -feliminate-dwarf2-dups.
4260 * Internationalization
4262 When supported by the host system, GDB will be built with
4263 internationalization (libintl). The task of marking up the sources is
4264 continued, we're looking forward to our first translation.
4268 Initial support for debugging programs compiled with the GNAT
4269 implementation of the Ada programming language has been integrated
4270 into GDB. In this release, support is limited to expression evaluation.
4272 * New native configurations
4274 GNU/Linux/m32r m32r-*-linux-gnu
4278 GDB's remote protocol now includes support for the 'p' packet. This
4279 packet is used to fetch individual registers from a remote inferior.
4281 * END-OF-LIFE registers[] compatibility module
4283 GDB's internal register infrastructure has been completely rewritten.
4284 The new infrastructure making possible the implementation of key new
4285 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4288 GDB 6.3 will be the last release to include the the registers[]
4289 compatibility module that allowed out-of-date configurations to
4290 continue to work. This change directly impacts the following
4300 powerpc bdm protocol
4302 Unless there is activity to revive these configurations, they will be
4303 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4305 * OBSOLETE configurations and files
4307 Configurations that have been declared obsolete in this release have
4308 been commented out. Unless there is activity to revive these
4309 configurations, the next release of GDB will have their sources
4310 permanently REMOVED.
4319 *** Changes in GDB 6.2.1:
4321 * MIPS `break main; run' gave an heuristic-fence-post warning
4323 When attempting to run even a simple program, a warning about
4324 heuristic-fence-post being hit would be reported. This problem has
4327 * MIPS IRIX 'long double' crashed GDB
4329 When examining a long double variable, GDB would get a segmentation
4330 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4331 IRIX long double values).
4335 A bug in the VAX stack code was causing problems with the "next"
4336 command. This problem has been fixed.
4338 *** Changes in GDB 6.2:
4340 * Fix for ``many threads''
4342 On GNU/Linux systems that use the NPTL threads library, a program
4343 rapidly creating and deleting threads would confuse GDB leading to the
4346 ptrace: No such process.
4347 thread_db_get_info: cannot get thread info: generic error
4349 This problem has been fixed.
4351 * "-async" and "-noasync" options removed.
4353 Support for the broken "-noasync" option has been removed (it caused
4356 * New ``start'' command.
4358 This command runs the program until the begining of the main procedure.
4360 * New BSD Kernel Data Access Library (libkvm) interface
4362 Using ``target kvm'' it is now possible to debug kernel core dumps and
4363 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4364 platforms. Currently supported (native-only) configurations are:
4366 FreeBSD/amd64 x86_64-*-freebsd*
4367 FreeBSD/i386 i?86-*-freebsd*
4368 NetBSD/i386 i?86-*-netbsd*
4369 NetBSD/m68k m68*-*-netbsd*
4370 NetBSD/sparc sparc-*-netbsd*
4371 OpenBSD/amd64 x86_64-*-openbsd*
4372 OpenBSD/i386 i?86-*-openbsd*
4373 OpenBSD/m68k m68*-openbsd*
4374 OpenBSD/sparc sparc-*-openbsd*
4376 * Signal trampoline code overhauled
4378 Many generic problems with GDB's signal handling code have been fixed.
4379 These include: backtraces through non-contiguous stacks; recognition
4380 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4381 call; backtrace through a signal trampoline; step into and out of
4382 signal handlers; and single-stepping in the signal trampoline.
4384 Please note that kernel bugs are a limiting factor here. These
4385 features have been shown to work on an s390 GNU/Linux system that
4386 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4388 * Cygwin support for DWARF 2 added.
4390 * New native configurations
4392 GNU/Linux/hppa hppa*-*-linux*
4393 OpenBSD/hppa hppa*-*-openbsd*
4394 OpenBSD/m68k m68*-*-openbsd*
4395 OpenBSD/m88k m88*-*-openbsd*
4396 OpenBSD/powerpc powerpc-*-openbsd*
4397 NetBSD/vax vax-*-netbsd*
4398 OpenBSD/vax vax-*-openbsd*
4400 * END-OF-LIFE frame compatibility module
4402 GDB's internal frame infrastructure has been completely rewritten.
4403 The new infrastructure making it possible to support key new features
4404 including DWARF 2 Call Frame Information. To aid in the task of
4405 migrating old configurations to this new infrastructure, a
4406 compatibility module, that allowed old configurations to continue to
4407 work, was also included.
4409 GDB 6.2 will be the last release to include this frame compatibility
4410 module. This change directly impacts the following configurations:
4420 Unless there is activity to revive these configurations, they will be
4421 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4423 * REMOVED configurations and files
4425 Sun 3, running SunOS 3 m68*-*-sunos3*
4426 Sun 3, running SunOS 4 m68*-*-sunos4*
4427 Sun 2, running SunOS 3 m68000-*-sunos3*
4428 Sun 2, running SunOS 4 m68000-*-sunos4*
4429 Motorola 680x0 running LynxOS m68*-*-lynxos*
4430 AT&T 3b1/Unix pc m68*-att-*
4431 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4432 decstation mips-dec-* mips-little-*
4433 riscos mips-*-riscos* mips-*-sysv*
4434 sonymips mips-sony-*
4435 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4437 *** Changes in GDB 6.1.1:
4439 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4441 The TUI (Text-mode User Interface) is now built as part of a default
4442 GDB configuration. It is enabled by either selecting the TUI with the
4443 command line option "-i=tui" or by running the separate "gdbtui"
4444 program. For more information on the TUI, see the manual "Debugging
4447 * Pending breakpoint support (also included in GDB 6.1)
4449 Support has been added to allow you to specify breakpoints in shared
4450 libraries that have not yet been loaded. If a breakpoint location
4451 cannot be found, and the "breakpoint pending" option is set to auto,
4452 GDB queries you if you wish to make the breakpoint pending on a future
4453 shared-library load. If and when GDB resolves the breakpoint symbol,
4454 the pending breakpoint is removed as one or more regular breakpoints
4457 Pending breakpoints are very useful for GCJ Java debugging.
4459 * Fixed ISO-C build problems
4461 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4462 non ISO-C code that stopped them being built using a more strict ISO-C
4463 compiler (e.g., IBM's C compiler).
4465 * Fixed build problem on IRIX 5
4467 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4468 wasn't able to compile compile on an IRIX 5 system.
4470 * Added execute permission to gdb/gdbserver/configure
4472 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4473 permission. This bug would cause configure to fail on a number of
4474 systems (Solaris, IRIX). Ref: server/519.
4476 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4478 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4479 has been updated to use constant array sizes.
4481 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4483 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4484 its generated DWARF Call Frame Info. This encoding was causing GDB to
4485 panic, that panic has been fixed. Ref: gdb/1628.
4487 * Fixed a problem when examining parameters in shared library code.
4489 When examining parameters in optimized shared library code generated
4490 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4491 not available''. GDB now correctly displays the variable's value.
4493 *** Changes in GDB 6.1:
4495 * Removed --with-mmalloc
4497 Support for the mmalloc memory manager has been removed, as it
4498 conflicted with the internal gdb byte cache.
4500 * Changes in AMD64 configurations
4502 The AMD64 target now includes the %cs and %ss registers. As a result
4503 the AMD64 remote protocol has changed; this affects the floating-point
4504 and SSE registers. If you rely on those registers for your debugging,
4505 you should upgrade gdbserver on the remote side.
4507 * Revised SPARC target
4509 The SPARC target has been completely revised, incorporating the
4510 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4511 support for LynxOS and SunOS 4 has been dropped. Calling functions
4512 from within GDB on operating systems with a non-executable stack
4513 (Solaris, OpenBSD) now works.
4517 GDB has a new C++ demangler which does a better job on the mangled
4518 names generated by current versions of g++. It also runs faster, so
4519 with this and other changes gdb should now start faster on large C++
4522 * DWARF 2 Location Expressions
4524 GDB support for location expressions has been extended to support function
4525 arguments and frame bases. Older versions of GDB could crash when they
4528 * C++ nested types and namespaces
4530 GDB's support for nested types and namespaces in C++ has been
4531 improved, especially if you use the DWARF 2 debugging format. (This
4532 is the default for recent versions of GCC on most platforms.)
4533 Specifically, if you have a class "Inner" defined within a class or
4534 namespace "Outer", then GDB realizes that the class's name is
4535 "Outer::Inner", not simply "Inner". This should greatly reduce the
4536 frequency of complaints about not finding RTTI symbols. In addition,
4537 if you are stopped at inside of a function defined within a namespace,
4538 GDB modifies its name lookup accordingly.
4540 * New native configurations
4542 NetBSD/amd64 x86_64-*-netbsd*
4543 OpenBSD/amd64 x86_64-*-openbsd*
4544 OpenBSD/alpha alpha*-*-openbsd*
4545 OpenBSD/sparc sparc-*-openbsd*
4546 OpenBSD/sparc64 sparc64-*-openbsd*
4548 * New debugging protocols
4550 M32R with SDI protocol m32r-*-elf*
4552 * "set prompt-escape-char" command deleted.
4554 The command "set prompt-escape-char" has been deleted. This command,
4555 and its very obscure effet on GDB's prompt, was never documented,
4556 tested, nor mentioned in the NEWS file.
4558 * OBSOLETE configurations and files
4560 Configurations that have been declared obsolete in this release have
4561 been commented out. Unless there is activity to revive these
4562 configurations, the next release of GDB will have their sources
4563 permanently REMOVED.
4565 Sun 3, running SunOS 3 m68*-*-sunos3*
4566 Sun 3, running SunOS 4 m68*-*-sunos4*
4567 Sun 2, running SunOS 3 m68000-*-sunos3*
4568 Sun 2, running SunOS 4 m68000-*-sunos4*
4569 Motorola 680x0 running LynxOS m68*-*-lynxos*
4570 AT&T 3b1/Unix pc m68*-att-*
4571 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4572 decstation mips-dec-* mips-little-*
4573 riscos mips-*-riscos* mips-*-sysv*
4574 sonymips mips-sony-*
4575 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4577 * REMOVED configurations and files
4579 SGI Irix-4.x mips-sgi-irix4 or iris4
4580 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4581 Z8000 simulator z8k-zilog-none or z8ksim
4582 Matsushita MN10200 w/simulator mn10200-*-*
4583 H8/500 simulator h8500-hitachi-hms or h8500hms
4584 HP/PA running BSD hppa*-*-bsd*
4585 HP/PA running OSF/1 hppa*-*-osf*
4586 HP/PA Pro target hppa*-*-pro*
4587 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4588 386BSD i[3456]86-*-bsd*
4589 Sequent family i[3456]86-sequent-sysv4*
4590 i[3456]86-sequent-sysv*
4591 i[3456]86-sequent-bsd*
4592 SPARC running LynxOS sparc-*-lynxos*
4593 SPARC running SunOS 4 sparc-*-sunos4*
4594 Tsqware Sparclet sparclet-*-*
4595 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4597 *** Changes in GDB 6.0:
4601 Support for debugging the Objective-C programming language has been
4602 integrated into GDB.
4604 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4606 DWARF 2's Call Frame Information makes available compiler generated
4607 information that more exactly describes the program's run-time stack.
4608 By using this information, GDB is able to provide more robust stack
4611 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4612 have been updated to use a new backtrace mechanism which includes
4613 DWARF 2 CFI support.
4617 GDB's remote protocol has been extended to include support for hosted
4618 file I/O (where the remote target uses GDB's file system). See GDB's
4619 remote protocol documentation for details.
4621 * All targets using the new architecture framework.
4623 All of GDB's targets have been updated to use the new internal
4624 architecture framework. The way is now open for future GDB releases
4625 to include cross-architecture native debugging support (i386 on amd64,
4628 * GNU/Linux's Thread Local Storage (TLS)
4630 GDB now includes support for for the GNU/Linux implementation of
4631 per-thread variables.
4633 * GNU/Linux's Native POSIX Thread Library (NPTL)
4635 GDB's thread code has been updated to work with either the new
4636 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4638 * Separate debug info.
4640 GDB, in conjunction with BINUTILS, now supports a mechanism for
4641 automatically loading debug information from a separate file. Instead
4642 of shipping full debug and non-debug versions of system libraries,
4643 system integrators can now instead ship just the stripped libraries
4644 and optional debug files.
4646 * DWARF 2 Location Expressions
4648 DWARF 2 Location Expressions allow the compiler to more completely
4649 describe the location of variables (even in optimized code) to the
4652 GDB now includes preliminary support for location expressions (support
4653 for DW_OP_piece is still missing).
4657 A number of long standing bugs that caused GDB to die while starting a
4658 Java application have been fixed. GDB's Java support is now
4659 considered "useable".
4661 * GNU/Linux support for fork, vfork, and exec.
4663 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4664 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4667 * GDB supports logging output to a file
4669 There are two new commands, "set logging" and "show logging", which can be
4670 used to capture GDB's output to a file.
4672 * The meaning of "detach" has changed for gdbserver
4674 The "detach" command will now resume the application, as documented. To
4675 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4678 * d10v, m68hc11 `regs' command deprecated
4680 The `info registers' command has been updated so that it displays the
4681 registers using a format identical to the old `regs' command.
4685 A new command, "maint set profile on/off", has been added. This command can
4686 be used to enable or disable profiling while running GDB, to profile a
4687 session or a set of commands. In addition there is a new configure switch,
4688 "--enable-profiling", which will cause GDB to be compiled with profiling
4689 data, for more informative profiling results.
4691 * Default MI syntax changed to "mi2".
4693 The default MI (machine interface) syntax, enabled by the command line
4694 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4695 "mi1", can be enabled by specifying the option "-i=mi1".
4697 Support for the original "mi0" syntax (included in GDB 5.0) has been
4700 Fix for gdb/192: removed extraneous space when displaying frame level.
4701 Fix for gdb/672: update changelist is now output in mi list format.
4702 Fix for gdb/702: a -var-assign that updates the value now shows up
4703 in a subsequent -var-update.
4705 * New native configurations.
4707 FreeBSD/amd64 x86_64-*-freebsd*
4709 * Multi-arched targets.
4711 HP/PA HPUX11 hppa*-*-hpux*
4712 Renesas M32R/D w/simulator m32r-*-elf*
4714 * OBSOLETE configurations and files
4716 Configurations that have been declared obsolete in this release have
4717 been commented out. Unless there is activity to revive these
4718 configurations, the next release of GDB will have their sources
4719 permanently REMOVED.
4721 Z8000 simulator z8k-zilog-none or z8ksim
4722 Matsushita MN10200 w/simulator mn10200-*-*
4723 H8/500 simulator h8500-hitachi-hms or h8500hms
4724 HP/PA running BSD hppa*-*-bsd*
4725 HP/PA running OSF/1 hppa*-*-osf*
4726 HP/PA Pro target hppa*-*-pro*
4727 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4728 Sequent family i[3456]86-sequent-sysv4*
4729 i[3456]86-sequent-sysv*
4730 i[3456]86-sequent-bsd*
4731 Tsqware Sparclet sparclet-*-*
4732 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4734 * REMOVED configurations and files
4737 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4738 IBM AIX PS/2 i[3456]86-*-aix
4739 i386 running Mach 3.0 i[3456]86-*-mach3*
4740 i386 running Mach i[3456]86-*-mach*
4741 i386 running OSF/1 i[3456]86-*osf1mk*
4742 HP/Apollo 68k Family m68*-apollo*-sysv*,
4744 m68*-hp-bsd*, m68*-hp-hpux*
4745 Argonaut Risc Chip (ARC) arc-*-*
4746 Mitsubishi D30V d30v-*-*
4747 Fujitsu FR30 fr30-*-elf*
4748 OS/9000 i[34]86-*-os9k
4749 I960 with MON960 i960-*-coff
4751 * MIPS $fp behavior changed
4753 The convenience variable $fp, for the MIPS, now consistently returns
4754 the address of the current frame's base. Previously, depending on the
4755 context, $fp could refer to either $sp or the current frame's base
4756 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4757 The GNU Source-Level Debugger''.
4759 *** Changes in GDB 5.3:
4761 * GNU/Linux shared library multi-threaded performance improved.
4763 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4764 `/proc', in preference to `ptrace' for memory reads. This may result
4765 in an improvement in the start-up time of multi-threaded, shared
4766 library applications when run under GDB. One GDB user writes: ``loads
4767 shared libs like mad''.
4769 * ``gdbserver'' now supports multi-threaded applications on some targets
4771 Support for debugging multi-threaded applications which use
4772 the GNU/Linux LinuxThreads package has been added for
4773 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4774 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4776 * GDB now supports C/C++ preprocessor macros.
4778 GDB now expands preprocessor macro invocations in C/C++ expressions,
4779 and provides various commands for showing macro definitions and how
4782 The new command `macro expand EXPRESSION' expands any macro
4783 invocations in expression, and shows the result.
4785 The new command `show macro MACRO-NAME' shows the definition of the
4786 macro named MACRO-NAME, and where it was defined.
4788 Most compilers don't include information about macros in the debugging
4789 information by default. In GCC 3.1, for example, you need to compile
4790 your program with the options `-gdwarf-2 -g3'. If the macro
4791 information is present in the executable, GDB will read it.
4793 * Multi-arched targets.
4795 DEC Alpha (partial) alpha*-*-*
4796 DEC VAX (partial) vax-*-*
4798 National Semiconductor NS32000 (partial) ns32k-*-*
4799 Motorola 68000 (partial) m68k-*-*
4800 Motorola MCORE mcore-*-*
4804 Fujitsu FRV architecture added by Red Hat frv*-*-*
4807 * New native configurations
4809 Alpha NetBSD alpha*-*-netbsd*
4810 SH NetBSD sh*-*-netbsdelf*
4811 MIPS NetBSD mips*-*-netbsd*
4812 UltraSPARC NetBSD sparc64-*-netbsd*
4814 * OBSOLETE configurations and files
4816 Configurations that have been declared obsolete in this release have
4817 been commented out. Unless there is activity to revive these
4818 configurations, the next release of GDB will have their sources
4819 permanently REMOVED.
4821 Mitsubishi D30V d30v-*-*
4822 OS/9000 i[34]86-*-os9k
4823 IBM AIX PS/2 i[3456]86-*-aix
4824 Fujitsu FR30 fr30-*-elf*
4825 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4826 Argonaut Risc Chip (ARC) arc-*-*
4827 i386 running Mach 3.0 i[3456]86-*-mach3*
4828 i386 running Mach i[3456]86-*-mach*
4829 i386 running OSF/1 i[3456]86-*osf1mk*
4830 HP/Apollo 68k Family m68*-apollo*-sysv*,
4832 m68*-hp-bsd*, m68*-hp-hpux*
4833 I960 with MON960 i960-*-coff
4835 * OBSOLETE languages
4837 CHILL, a Pascal like language used by telecommunications companies.
4839 * REMOVED configurations and files
4841 AMD 29k family via UDI a29k-amd-udi, udi29k
4842 A29K VxWorks a29k-*-vxworks
4843 AMD 29000 embedded, using EBMON a29k-none-none
4844 AMD 29000 embedded with COFF a29k-none-coff
4845 AMD 29000 embedded with a.out a29k-none-aout
4847 testsuite/gdb.hp/gdb.threads-hp/ directory
4849 * New command "set max-user-call-depth <nnn>"
4851 This command allows the user to limit the call depth of user-defined
4852 commands. The default is 1024.
4854 * Changes in FreeBSD/i386 native debugging.
4856 Support for the "generate-core-file" has been added.
4858 * New commands "dump", "append", and "restore".
4860 These commands allow data to be copied from target memory
4861 to a bfd-format or binary file (dump and append), and back
4862 from a file into memory (restore).
4864 * Improved "next/step" support on multi-processor Alpha Tru64.
4866 The previous single-step mechanism could cause unpredictable problems,
4867 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4868 of a software single-step mechanism prevents this.
4870 *** Changes in GDB 5.2.1:
4878 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4879 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4880 Fix, by Joel Brobecker imported from mainline.
4882 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4883 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4884 Fix, by Fred Fish, imported from mainline.
4886 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4887 Surprisingly enough, it works now.
4888 By Michal Ludvig, imported from mainline.
4890 i386 hardware watchpoint support:
4891 avoid misses on second run for some targets.
4892 By Pierre Muller, imported from mainline.
4894 *** Changes in GDB 5.2:
4896 * New command "set trust-readonly-sections on[off]".
4898 This command is a hint that tells gdb that read-only sections
4899 really are read-only (ie. that their contents will not change).
4900 In this mode, gdb will go to the object file rather than the
4901 target to read memory from read-only sections (such as ".text").
4902 This can be a significant performance improvement on some
4903 (notably embedded) targets.
4905 * New command "generate-core-file" (or "gcore").
4907 This new gdb command allows the user to drop a core file of the child
4908 process state at any time. So far it's been implemented only for
4909 GNU/Linux and Solaris, but should be relatively easily ported to other
4910 hosts. Argument is core file name (defaults to core.<pid>).
4912 * New command line option
4914 GDB now accepts --pid or -p followed by a process id.
4916 * Change in command line behavior -- corefiles vs. process ids.
4918 There is a subtle behavior in the way in which GDB handles
4919 command line arguments. The first non-flag argument is always
4920 a program to debug, but the second non-flag argument may either
4921 be a corefile or a process id. Previously, GDB would attempt to
4922 open the second argument as a corefile, and if that failed, would
4923 issue a superfluous error message and then attempt to attach it as
4924 a process. Now, if the second argument begins with a non-digit,
4925 it will be treated as a corefile. If it begins with a digit,
4926 GDB will attempt to attach it as a process, and if no such process
4927 is found, will then attempt to open it as a corefile.
4929 * Changes in ARM configurations.
4931 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4932 configuration is fully multi-arch.
4934 * New native configurations
4936 ARM NetBSD arm*-*-netbsd*
4937 x86 OpenBSD i[3456]86-*-openbsd*
4938 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4939 Sparc64 running FreeBSD sparc64-*-freebsd*
4943 Sanyo XStormy16 xstormy16-elf
4945 * OBSOLETE configurations and files
4947 Configurations that have been declared obsolete in this release have
4948 been commented out. Unless there is activity to revive these
4949 configurations, the next release of GDB will have their sources
4950 permanently REMOVED.
4952 AMD 29k family via UDI a29k-amd-udi, udi29k
4953 A29K VxWorks a29k-*-vxworks
4954 AMD 29000 embedded, using EBMON a29k-none-none
4955 AMD 29000 embedded with COFF a29k-none-coff
4956 AMD 29000 embedded with a.out a29k-none-aout
4958 testsuite/gdb.hp/gdb.threads-hp/ directory
4960 * REMOVED configurations and files
4962 TI TMS320C80 tic80-*-*
4964 PowerPC Solaris powerpcle-*-solaris*
4965 PowerPC Windows NT powerpcle-*-cygwin32
4966 PowerPC Netware powerpc-*-netware*
4967 Harris/CXUX m88k m88*-harris-cxux*
4968 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4969 ns32k-utek-sysv* ns32k-utek-*
4970 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4971 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4972 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4973 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4974 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4976 * Changes to command line processing
4978 The new `--args' feature can be used to specify command-line arguments
4979 for the inferior from gdb's command line.
4981 * Changes to key bindings
4983 There is a new `operate-and-get-next' function bound to `C-o'.
4985 *** Changes in GDB 5.1.1
4987 Fix compile problem on DJGPP.
4989 Fix a problem with floating-point registers on the i386 being
4992 Fix to stop GDB crashing on .debug_str debug info.
4994 Numerous documentation fixes.
4996 Numerous testsuite fixes.
4998 *** Changes in GDB 5.1:
5000 * New native configurations
5002 Alpha FreeBSD alpha*-*-freebsd*
5003 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5004 MIPS GNU/Linux mips*-*-linux*
5005 MIPS SGI Irix 6.x mips*-sgi-irix6*
5006 ia64 AIX ia64-*-aix*
5007 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5011 Motorola 68HC11 and 68HC12 m68hc11-elf
5013 UltraSparc running GNU/Linux sparc64-*-linux*
5015 * OBSOLETE configurations and files
5017 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5018 Harris/CXUX m88k m88*-harris-cxux*
5019 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5020 ns32k-utek-sysv* ns32k-utek-*
5021 TI TMS320C80 tic80-*-*
5023 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5024 PowerPC Solaris powerpcle-*-solaris*
5025 PowerPC Windows NT powerpcle-*-cygwin32
5026 PowerPC Netware powerpc-*-netware*
5027 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5028 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5029 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5030 Apple Macintosh (MPW) host N/A
5032 stuff.c (Program to stuff files into a specially prepared space in kdb)
5033 kdb-start.c (Main loop for the standalone kernel debugger)
5035 Configurations that have been declared obsolete in this release have
5036 been commented out. Unless there is activity to revive these
5037 configurations, the next release of GDB will have their sources
5038 permanently REMOVED.
5040 * REMOVED configurations and files
5042 Altos 3068 m68*-altos-*
5043 Convex c1-*-*, c2-*-*
5045 ARM RISCix arm-*-* (as host)
5049 * GDB has been converted to ISO C.
5051 GDB's source code has been converted to ISO C. In particular, the
5052 sources are fully protoized, and rely on standard headers being
5057 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5059 * The MI enabled by default.
5061 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5062 revised and enabled by default. Packages which use GDB as a debugging
5063 engine behind a UI or another front end are encouraged to switch to
5064 using the GDB/MI interface, instead of the old annotations interface
5065 which is now deprecated.
5067 * Support for debugging Pascal programs.
5069 GDB now includes support for debugging Pascal programs. The following
5070 main features are supported:
5072 - Pascal-specific data types such as sets;
5074 - automatic recognition of Pascal sources based on file-name
5077 - Pascal-style display of data types, variables, and functions;
5079 - a Pascal expression parser.
5081 However, some important features are not yet supported.
5083 - Pascal string operations are not supported at all;
5085 - there are some problems with boolean types;
5087 - Pascal type hexadecimal constants are not supported
5088 because they conflict with the internal variables format;
5090 - support for Pascal objects and classes is not full yet;
5092 - unlike Pascal, GDB is case-sensitive for symbol names.
5094 * Changes in completion.
5096 Commands such as `shell', `run' and `set args', which pass arguments
5097 to inferior programs, now complete on file names, similar to what
5098 users expect at the shell prompt.
5100 Commands which accept locations, such as `disassemble', `print',
5101 `breakpoint', `until', etc. now complete on filenames as well as
5102 program symbols. Thus, if you type "break foob TAB", and the source
5103 files linked into the programs include `foobar.c', that file name will
5104 be one of the candidates for completion. However, file names are not
5105 considered for completion after you typed a colon that delimits a file
5106 name from a name of a function in that file, as in "break foo.c:bar".
5108 `set demangle-style' completes on available demangling styles.
5110 * New platform-independent commands:
5112 It is now possible to define a post-hook for a command as well as a
5113 hook that runs before the command. For more details, see the
5114 documentation of `hookpost' in the GDB manual.
5116 * Changes in GNU/Linux native debugging.
5118 Support for debugging multi-threaded programs has been completely
5119 revised for all platforms except m68k and sparc. You can now debug as
5120 many threads as your system allows you to have.
5122 Attach/detach is supported for multi-threaded programs.
5124 Support for SSE registers was added for x86. This doesn't work for
5125 multi-threaded programs though.
5127 * Changes in MIPS configurations.
5129 Multi-arch support is enabled for all MIPS configurations.
5131 GDB can now be built as native debugger on SGI Irix 6.x systems for
5132 debugging n32 executables. (Debugging 64-bit executables is not yet
5135 * Unified support for hardware watchpoints in all x86 configurations.
5137 Most (if not all) native x86 configurations support hardware-assisted
5138 breakpoints and watchpoints in a unified manner. This support
5139 implements debug register sharing between watchpoints, which allows to
5140 put a virtually infinite number of watchpoints on the same address,
5141 and also supports watching regions up to 16 bytes with several debug
5144 The new maintenance command `maintenance show-debug-regs' toggles
5145 debugging print-outs in functions that insert, remove, and test
5146 watchpoints and hardware breakpoints.
5148 * Changes in the DJGPP native configuration.
5150 New command ``info dos sysinfo'' displays assorted information about
5151 the CPU, OS, memory, and DPMI server.
5153 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5154 display information about segment descriptors stored in GDT, LDT, and
5157 New commands ``info dos pde'' and ``info dos pte'' display entries
5158 from Page Directory and Page Tables (for now works with CWSDPMI only).
5159 New command ``info dos address-pte'' displays the Page Table entry for
5160 a given linear address.
5162 GDB can now pass command lines longer than 126 characters to the
5163 program being debugged (requires an update to the libdbg.a library
5164 which is part of the DJGPP development kit).
5166 DWARF2 debug info is now supported.
5168 It is now possible to `step' and `next' through calls to `longjmp'.
5170 * Changes in documentation.
5172 All GDB documentation was converted to GFDL, the GNU Free
5173 Documentation License.
5175 Tracepoints-related commands are now fully documented in the GDB
5178 TUI, the Text-mode User Interface, is now documented in the manual.
5180 Tracepoints-related commands are now fully documented in the GDB
5183 The "GDB Internals" manual now has an index. It also includes
5184 documentation of `ui_out' functions, GDB coding standards, x86
5185 hardware watchpoints, and memory region attributes.
5187 * GDB's version number moved to ``version.in''
5189 The Makefile variable VERSION has been replaced by the file
5190 ``version.in''. People creating GDB distributions should update the
5191 contents of this file.
5195 GUD support is now a standard part of the EMACS distribution.
5197 *** Changes in GDB 5.0:
5199 * Improved support for debugging FP programs on x86 targets
5201 Unified and much-improved support for debugging floating-point
5202 programs on all x86 targets. In particular, ``info float'' now
5203 displays the FP registers in the same format on all x86 targets, with
5204 greater level of detail.
5206 * Improvements and bugfixes in hardware-assisted watchpoints
5208 It is now possible to watch array elements, struct members, and
5209 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5210 on x86 targets no longer erroneously trigger when the address is
5213 * Improvements in the native DJGPP version of GDB
5215 The distribution now includes all the scripts and auxiliary files
5216 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5217 machines ``out of the box''.
5219 The DJGPP version can now debug programs that use signals. It is
5220 possible to catch signals that happened in the debuggee, deliver
5221 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5222 would kill the program being debugged.) Programs that hook hardware
5223 interrupts (keyboard, timer, etc.) can also be debugged.
5225 It is now possible to debug DJGPP programs that redirect their
5226 standard handles or switch them to raw (as opposed to cooked) mode, or
5227 even close them. The command ``run < foo > bar'' works as expected,
5228 and ``info terminal'' reports useful information about the debuggee's
5229 terminal, including raw/cooked mode, redirection, etc.
5231 The DJGPP version now uses termios functions for console I/O, which
5232 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5235 DOS-style file names with drive letters are now fully supported by
5238 It is now possible to debug DJGPP programs that switch their working
5239 directory. It is also possible to rerun the debuggee any number of
5240 times without restarting GDB; thus, you can use the same setup,
5241 breakpoints, etc. for many debugging sessions.
5243 * New native configurations
5245 ARM GNU/Linux arm*-*-linux*
5246 PowerPC GNU/Linux powerpc-*-linux*
5250 Motorola MCore mcore-*-*
5251 x86 VxWorks i[3456]86-*-vxworks*
5252 PowerPC VxWorks powerpc-*-vxworks*
5253 TI TMS320C80 tic80-*-*
5255 * OBSOLETE configurations
5257 Altos 3068 m68*-altos-*
5258 Convex c1-*-*, c2-*-*
5260 ARM RISCix arm-*-* (as host)
5263 Configurations that have been declared obsolete will be commented out,
5264 but the code will be left in place. If there is no activity to revive
5265 these configurations before the next release of GDB, the sources will
5266 be permanently REMOVED.
5268 * Gould support removed
5270 Support for the Gould PowerNode and NP1 has been removed.
5272 * New features for SVR4
5274 On SVR4 native platforms (such as Solaris), if you attach to a process
5275 without first loading a symbol file, GDB will now attempt to locate and
5276 load symbols from the running process's executable file.
5278 * Many C++ enhancements
5280 C++ support has been greatly improved. Overload resolution now works properly
5281 in almost all cases. RTTI support is on the way.
5283 * Remote targets can connect to a sub-program
5285 A popen(3) style serial-device has been added. This device starts a
5286 sub-process (such as a stand-alone simulator) and then communicates
5287 with that. The sub-program to run is specified using the syntax
5288 ``|<program> <args>'' vis:
5290 (gdb) set remotedebug 1
5291 (gdb) target extended-remote |mn10300-elf-sim program-args
5293 * MIPS 64 remote protocol
5295 A long standing bug in the mips64 remote protocol where by GDB
5296 expected certain 32 bit registers (ex SR) to be transfered as 32
5297 instead of 64 bits has been fixed.
5299 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5300 added to provide backward compatibility with older versions of GDB.
5302 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5304 The command ``set remotebinarydownload'' command has been replaced by
5305 ``set remote X-packet''. Other commands in ``set remote'' family
5306 include ``set remote P-packet''.
5308 * Breakpoint commands accept ranges.
5310 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5311 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5312 ``tracepoint passcount'' also accepts a range of tracepoints.
5314 * ``apropos'' command added.
5316 The ``apropos'' command searches through command names and
5317 documentation strings, printing out matches, making it much easier to
5318 try to find a command that does what you are looking for.
5322 A new machine oriented interface (MI) has been added to GDB. This
5323 interface is designed for debug environments running GDB as a separate
5324 process. This is part of the long term libGDB project. See the
5325 "GDB/MI" chapter of the GDB manual for further information. It can be
5326 enabled by configuring with:
5328 .../configure --enable-gdbmi
5330 *** Changes in GDB-4.18:
5332 * New native configurations
5334 HP-UX 10.20 hppa*-*-hpux10.20
5335 HP-UX 11.x hppa*-*-hpux11.0*
5336 M68K GNU/Linux m68*-*-linux*
5340 Fujitsu FR30 fr30-*-elf*
5341 Intel StrongARM strongarm-*-*
5342 Mitsubishi D30V d30v-*-*
5344 * OBSOLETE configurations
5346 Gould PowerNode, NP1 np1-*-*, pn-*-*
5348 Configurations that have been declared obsolete will be commented out,
5349 but the code will be left in place. If there is no activity to revive
5350 these configurations before the next release of GDB, the sources will
5351 be permanently REMOVED.
5355 As a compatibility experiment, GDB's source files buildsym.h and
5356 buildsym.c have been converted to pure standard C, no longer
5357 containing any K&R compatibility code. We believe that all systems in
5358 use today either come with a standard C compiler, or have a GCC port
5359 available. If this is not true, please report the affected
5360 configuration to bug-gdb@gnu.org immediately. See the README file for
5361 information about getting a standard C compiler if you don't have one
5366 GDB now uses readline 2.2.
5368 * set extension-language
5370 You can now control the mapping between filename extensions and source
5371 languages by using the `set extension-language' command. For instance,
5372 you can ask GDB to treat .c files as C++ by saying
5373 set extension-language .c c++
5374 The command `info extensions' lists all of the recognized extensions
5375 and their associated languages.
5377 * Setting processor type for PowerPC and RS/6000
5379 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5380 you can use the `set processor' command to specify what variant of the
5381 PowerPC family you are debugging. The command
5385 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5386 following PowerPC and RS6000 variants:
5388 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5389 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5391 403GC IBM PowerPC 403GC
5392 505 Motorola PowerPC 505
5393 860 Motorola PowerPC 860 or 850
5394 601 Motorola PowerPC 601
5395 602 Motorola PowerPC 602
5396 603 Motorola/IBM PowerPC 603 or 603e
5397 604 Motorola PowerPC 604 or 604e
5398 750 Motorola/IBM PowerPC 750 or 750
5400 At the moment, this command just tells GDB what to name the
5401 special-purpose processor registers. Since almost all the affected
5402 registers are inaccessible to user-level programs, this command is
5403 only useful for remote debugging in its present form.
5407 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5408 more extensive support for HP-UX. Added features include shared
5409 library support, kernel threads and hardware watchpoints for 11.00,
5410 support for HP's ANSI C and C++ compilers, and a compatibility mode
5411 for xdb and dbx commands.
5415 HP's donation includes the new concept of catchpoints, which is a
5416 generalization of the old catch command. On HP-UX, it is now possible
5417 to catch exec, fork, and vfork, as well as library loading.
5419 This means that the existing catch command has changed; its first
5420 argument now specifies the type of catch to be set up. See the
5421 output of "help catch" for a list of catchpoint types.
5423 * Debugging across forks
5425 On HP-UX, you can choose which process to debug when a fork() happens
5430 HP has donated a curses-based terminal user interface (TUI). To get
5431 it, build with --enable-tui. Although this can be enabled for any
5432 configuration, at present it only works for native HP debugging.
5434 * GDB remote protocol additions
5436 A new protocol packet 'X' that writes binary data is now available.
5437 Default behavior is to try 'X', then drop back to 'M' if the stub
5438 fails to respond. The settable variable `remotebinarydownload'
5439 allows explicit control over the use of 'X'.
5441 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5442 full 64-bit address. The command
5444 set remoteaddresssize 32
5446 can be used to revert to the old behaviour. For existing remote stubs
5447 the change should not be noticed, as the additional address information
5450 In order to assist in debugging stubs, you may use the maintenance
5451 command `packet' to send any text string to the stub. For instance,
5453 maint packet heythere
5455 sends the packet "$heythere#<checksum>". Note that it is very easy to
5456 disrupt a debugging session by sending the wrong packet at the wrong
5459 The compare-sections command allows you to compare section data on the
5460 target to what is in the executable file without uploading or
5461 downloading, by comparing CRC checksums.
5463 * Tracing can collect general expressions
5465 You may now collect general expressions at tracepoints. This requires
5466 further additions to the target-side stub; see tracepoint.c and
5467 doc/agentexpr.texi for further details.
5469 * mask-address variable for Mips
5471 For Mips targets, you may control the zeroing of the upper 32 bits of
5472 a 64-bit address by entering `set mask-address on'. This is mainly
5473 of interest to users of embedded R4xxx and R5xxx processors.
5475 * Higher serial baud rates
5477 GDB's serial code now allows you to specify baud rates 57600, 115200,
5478 230400, and 460800 baud. (Note that your host system may not be able
5479 to achieve all of these rates.)
5483 The i960 configuration now includes an initial implementation of a
5484 builtin simulator, contributed by Jim Wilson.
5487 *** Changes in GDB-4.17:
5489 * New native configurations
5491 Alpha GNU/Linux alpha*-*-linux*
5492 Unixware 2.x i[3456]86-unixware2*
5493 Irix 6.x mips*-sgi-irix6*
5494 PowerPC GNU/Linux powerpc-*-linux*
5495 PowerPC Solaris powerpcle-*-solaris*
5496 Sparc GNU/Linux sparc-*-linux*
5497 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5501 Argonaut Risc Chip (ARC) arc-*-*
5502 Hitachi H8/300S h8300*-*-*
5503 Matsushita MN10200 w/simulator mn10200-*-*
5504 Matsushita MN10300 w/simulator mn10300-*-*
5505 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5506 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5507 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5508 Mitsubishi D10V w/simulator d10v-*-*
5509 Mitsubishi M32R/D w/simulator m32r-*-elf*
5510 Tsqware Sparclet sparclet-*-*
5511 NEC V850 w/simulator v850-*-*
5513 * New debugging protocols
5515 ARM with RDI protocol arm*-*-*
5516 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5517 DDB and LSI variants of PMON protocol mips*-*-*
5518 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5519 PowerPC with SDS protocol powerpc{,le}-*-eabi
5520 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5524 All configurations can now understand and use the DWARF 2 debugging
5525 format. The choice is automatic, if the symbol file contains DWARF 2
5530 GDB now includes basic Java language support. This support is
5531 only useful with Java compilers that produce native machine code.
5533 * solib-absolute-prefix and solib-search-path
5535 For SunOS and SVR4 shared libraries, you may now set the prefix for
5536 loading absolute shared library symbol files, and the search path for
5537 locating non-absolute shared library symbol files.
5539 * Live range splitting
5541 GDB can now effectively debug code for which GCC has performed live
5542 range splitting as part of its optimization. See gdb/doc/LRS for
5543 more details on the expected format of the stabs information.
5547 GDB's support for the GNU Hurd, including thread debugging, has been
5548 updated to work with current versions of the Hurd.
5552 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5553 instruction set. ARM GDB automatically detects when Thumb
5554 instructions are in use, and adjusts disassembly and backtracing
5559 GDB's MIPS target configurations now handle the MIP16 16-bit
5564 GDB now includes support for overlays; if an executable has been
5565 linked such that multiple sections are based at the same address, GDB
5566 will decide which section to use for symbolic info. You can choose to
5567 control the decision manually, using overlay commands, or implement
5568 additional target-side support and use "overlay load-target" to bring
5569 in the overlay mapping. Do "help overlay" for more detail.
5573 The command "info symbol <address>" displays information about
5574 the symbol at the specified address.
5578 The standard remote protocol now includes an extension that allows
5579 asynchronous collection and display of trace data. This requires
5580 extensive support in the target-side debugging stub. Tracing mode
5581 includes a new interaction mode in GDB and new commands: see the
5582 file tracepoint.c for more details.
5586 Configurations for embedded MIPS now include a simulator contributed
5587 by Cygnus Solutions. The simulator supports the instruction sets
5588 of most MIPS variants.
5592 Sparc configurations may now include the ERC32 simulator contributed
5593 by the European Space Agency. The simulator is not built into
5594 Sparc targets by default; configure with --enable-sim to include it.
5598 For target configurations that may include multiple variants of a
5599 basic architecture (such as MIPS and SH), you may now set the
5600 architecture explicitly. "set arch" sets, "info arch" lists
5601 the possible architectures.
5603 *** Changes in GDB-4.16:
5605 * New native configurations
5607 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5608 M68K NetBSD m68k-*-netbsd*
5609 PowerPC AIX 4.x powerpc-*-aix*
5610 PowerPC MacOS powerpc-*-macos*
5611 PowerPC Windows NT powerpcle-*-cygwin32
5612 RS/6000 AIX 4.x rs6000-*-aix4*
5616 ARM with RDP protocol arm-*-*
5617 I960 with MON960 i960-*-coff
5618 MIPS VxWorks mips*-*-vxworks*
5619 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5620 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5622 Matra Sparclet sparclet-*-*
5626 The powerpc-eabi configuration now includes the PSIM simulator,
5627 contributed by Andrew Cagney, with assistance from Mike Meissner.
5628 PSIM is a very elaborate model of the PowerPC, including not only
5629 basic instruction set execution, but also details of execution unit
5630 performance and I/O hardware. See sim/ppc/README for more details.
5634 GDB now works with Solaris 2.5.
5636 * Windows 95/NT native
5638 GDB will now work as a native debugger on Windows 95 and Windows NT.
5639 To build it from source, you must use the "gnu-win32" environment,
5640 which uses a DLL to emulate enough of Unix to run the GNU tools.
5641 Further information, binaries, and sources are available at
5642 ftp.cygnus.com, under pub/gnu-win32.
5644 * dont-repeat command
5646 If a user-defined command includes the command `dont-repeat', then the
5647 command will not be repeated if the user just types return. This is
5648 useful if the command is time-consuming to run, so that accidental
5649 extra keystrokes don't run the same command many times.
5651 * Send break instead of ^C
5653 The standard remote protocol now includes an option to send a break
5654 rather than a ^C to the target in order to interrupt it. By default,
5655 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5657 * Remote protocol timeout
5659 The standard remote protocol includes a new variable `remotetimeout'
5660 that allows you to set the number of seconds before GDB gives up trying
5661 to read from the target. The default value is 2.
5663 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5665 By default GDB will automatically keep track of objects as they are
5666 loaded and unloaded by the dynamic linker. By using the command `set
5667 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5668 when shared library events occur, thus allowing you to set breakpoints
5669 in shared libraries which are explicitly loaded by the inferior.
5671 Note this feature does not work on hpux8. On hpux9 you must link
5672 /usr/lib/end.o into your program. This feature should work
5673 automatically on hpux10.
5675 * Irix 5.x hardware watchpoint support
5677 Irix 5 configurations now support the use of hardware watchpoints.
5679 * Mips protocol "SYN garbage limit"
5681 When debugging a Mips target using the `target mips' protocol, you
5682 may set the number of characters that GDB will ignore by setting
5683 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5684 every character. The default value is 1050.
5686 * Recording and replaying remote debug sessions
5688 If you set `remotelogfile' to the name of a file, gdb will write to it
5689 a recording of a remote debug session. This recording may then be
5690 replayed back to gdb using "gdbreplay". See gdbserver/README for
5691 details. This is useful when you have a problem with GDB while doing
5692 remote debugging; you can make a recording of the session and send it
5693 to someone else, who can then recreate the problem.
5695 * Speedups for remote debugging
5697 GDB includes speedups for downloading and stepping MIPS systems using
5698 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5699 and more efficient S-record downloading.
5701 * Memory use reductions and statistics collection
5703 GDB now uses less memory and reports statistics about memory usage.
5704 Try the `maint print statistics' command, for example.
5706 *** Changes in GDB-4.15:
5708 * Psymtabs for XCOFF
5710 The symbol reader for AIX GDB now uses partial symbol tables. This
5711 can greatly improve startup time, especially for large executables.
5713 * Remote targets use caching
5715 Remote targets now use a data cache to speed up communication with the
5716 remote side. The data cache could lead to incorrect results because
5717 it doesn't know about volatile variables, thus making it impossible to
5718 debug targets which use memory mapped I/O devices. `set remotecache
5719 off' turns the the data cache off.
5721 * Remote targets may have threads
5723 The standard remote protocol now includes support for multiple threads
5724 in the target system, using new protocol commands 'H' and 'T'. See
5725 gdb/remote.c for details.
5729 If GDB is configured with `--enable-netrom', then it will include
5730 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5731 acts as though it is a bank of ROM on the target board, but you can
5732 write into it over the network. GDB's support consists only of
5733 support for fast loading into the emulated ROM; to debug, you must use
5734 another protocol, such as standard remote protocol. The usual
5735 sequence is something like
5737 target nrom <netrom-hostname>
5739 target remote <netrom-hostname>:1235
5743 GDB now includes support for the Apple Macintosh, as a host only. It
5744 may be run as either an MPW tool or as a standalone application, and
5745 it can debug through the serial port. All the usual GDB commands are
5746 available, but to the target command, you must supply "serial" as the
5747 device type instead of "/dev/ttyXX". See mpw-README in the main
5748 directory for more information on how to build. The MPW configuration
5749 scripts */mpw-config.in support only a few targets, and only the
5750 mips-idt-ecoff target has been tested.
5754 GDB configuration now uses autoconf. This is not user-visible,
5755 but does simplify configuration and building.
5759 GDB now supports hpux10.
5761 *** Changes in GDB-4.14:
5763 * New native configurations
5765 x86 FreeBSD i[345]86-*-freebsd
5766 x86 NetBSD i[345]86-*-netbsd
5767 NS32k NetBSD ns32k-*-netbsd
5768 Sparc NetBSD sparc-*-netbsd
5772 A29K VxWorks a29k-*-vxworks
5773 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5774 CPU32 EST-300 emulator m68*-*-est*
5775 PowerPC ELF powerpc-*-elf
5778 * Alpha OSF/1 support for procfs
5780 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5781 possible to attach to running processes. As the mounting of the /proc
5782 filesystem is optional on the Alpha, GDB automatically determines
5783 the availability of /proc during startup. This can lead to problems
5784 if /proc is unmounted after GDB has been started.
5786 * Arguments to user-defined commands
5788 User commands may accept up to 10 arguments separated by whitespace.
5789 Arguments are accessed within the user command via $arg0..$arg9. A
5792 print $arg0 + $arg1 + $arg2
5794 To execute the command use:
5797 Defines the command "adder" which prints the sum of its three arguments.
5798 Note the arguments are text substitutions, so they may reference variables,
5799 use complex expressions, or even perform inferior function calls.
5801 * New `if' and `while' commands
5803 This makes it possible to write more sophisticated user-defined
5804 commands. Both commands take a single argument, which is the
5805 expression to evaluate, and must be followed by the commands to
5806 execute, one per line, if the expression is nonzero, the list being
5807 terminated by the word `end'. The `if' command list may include an
5808 `else' word, which causes the following commands to be executed only
5809 if the expression is zero.
5811 * Fortran source language mode
5813 GDB now includes partial support for Fortran 77. It will recognize
5814 Fortran programs and can evaluate a subset of Fortran expressions, but
5815 variables and functions may not be handled correctly. GDB will work
5816 with G77, but does not yet know much about symbols emitted by other
5819 * Better HPUX support
5821 Most debugging facilities now work on dynamic executables for HPPAs
5822 running hpux9 or later. You can attach to running dynamically linked
5823 processes, but by default the dynamic libraries will be read-only, so
5824 for instance you won't be able to put breakpoints in them. To change
5825 that behavior do the following before running the program:
5831 This will cause the libraries to be mapped private and read-write.
5832 To revert to the normal behavior, do this:
5838 You cannot set breakpoints or examine data in the library until after
5839 the library is loaded if the function/data symbols do not have
5842 GDB can now also read debug symbols produced by the HP C compiler on
5843 HPPAs (sorry, no C++, Fortran or 68k support).
5845 * Target byte order now dynamically selectable
5847 You can choose which byte order to use with a target system, via the
5848 commands "set endian big" and "set endian little", and you can see the
5849 current setting by using "show endian". You can also give the command
5850 "set endian auto", in which case GDB will use the byte order
5851 associated with the executable. Currently, only embedded MIPS
5852 configurations support dynamic selection of target byte order.
5854 * New DOS host serial code
5856 This version uses DPMI interrupts to handle buffered I/O, so you
5857 no longer need to run asynctsr when debugging boards connected to
5860 *** Changes in GDB-4.13:
5862 * New "complete" command
5864 This lists all the possible completions for the rest of the line, if it
5865 were to be given as a command itself. This is intended for use by emacs.
5867 * Trailing space optional in prompt
5869 "set prompt" no longer adds a space for you after the prompt you set. This
5870 allows you to set a prompt which ends in a space or one that does not.
5872 * Breakpoint hit counts
5874 "info break" now displays a count of the number of times the breakpoint
5875 has been hit. This is especially useful in conjunction with "ignore"; you
5876 can ignore a large number of breakpoint hits, look at the breakpoint info
5877 to see how many times the breakpoint was hit, then run again, ignoring one
5878 less than that number, and this will get you quickly to the last hit of
5881 * Ability to stop printing at NULL character
5883 "set print null-stop" will cause GDB to stop printing the characters of
5884 an array when the first NULL is encountered. This is useful when large
5885 arrays actually contain only short strings.
5887 * Shared library breakpoints
5889 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5890 breakpoints in shared libraries before the executable is run.
5892 * Hardware watchpoints
5894 There is a new hardware breakpoint for the watch command for sparclite
5895 targets. See gdb/sparclite/hw_breakpoint.note.
5897 Hardware watchpoints are also now supported under GNU/Linux.
5901 Annotations have been added. These are for use with graphical interfaces,
5902 and are still experimental. Currently only gdba.el uses these.
5904 * Improved Irix 5 support
5906 GDB now works properly with Irix 5.2.
5908 * Improved HPPA support
5910 GDB now works properly with the latest GCC and GAS.
5912 * New native configurations
5914 Sequent PTX4 i[34]86-sequent-ptx4
5915 HPPA running OSF/1 hppa*-*-osf*
5916 Atari TT running SVR4 m68*-*-sysv4*
5917 RS/6000 LynxOS rs6000-*-lynxos*
5921 OS/9000 i[34]86-*-os9k
5922 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5925 * Hitachi SH7000 and E7000-PC ICE support
5927 There is now support for communicating with the Hitachi E7000-PC ICE.
5928 This is available automatically when GDB is configured for the SH.
5932 As usual, a variety of small fixes and improvements, both generic
5933 and configuration-specific. See the ChangeLog for more detail.
5935 *** Changes in GDB-4.12:
5937 * Irix 5 is now supported
5941 GDB-4.12 on the HPPA has a number of changes which make it unable
5942 to debug the output from the currently released versions of GCC and
5943 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5944 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5945 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5948 *** Changes in GDB-4.11:
5950 * User visible changes:
5954 The "set remotedebug" option is now consistent between the mips remote
5955 target, remote targets using the gdb-specific protocol, UDI (AMD's
5956 debug protocol for the 29k) and the 88k bug monitor. It is now an
5957 integer specifying a debug level (normally 0 or 1, but 2 means more
5958 debugging info for the mips target).
5960 * DEC Alpha native support
5962 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5963 debug info, but GDB works fairly well with the DEC compiler and should
5964 work with a future GCC release. See the README file for a few
5965 Alpha-specific notes.
5967 * Preliminary thread implementation
5969 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5971 * LynxOS native and target support for 386
5973 This release has been hosted on LynxOS 2.2, and also can be configured
5974 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5977 * Improvements in C++ mangling/demangling.
5979 This release has much better g++ debugging, specifically in name
5980 mangling/demangling, virtual function calls, print virtual table,
5981 call methods, ...etc.
5983 *** Changes in GDB-4.10:
5985 * User visible changes:
5987 Remote debugging using the GDB-specific (`target remote') protocol now
5988 supports the `load' command. This is only useful if you have some
5989 other way of getting the stub to the target system, and you can put it
5990 somewhere in memory where it won't get clobbered by the download.
5992 Filename completion now works.
5994 When run under emacs mode, the "info line" command now causes the
5995 arrow to point to the line specified. Also, "info line" prints
5996 addresses in symbolic form (as well as hex).
5998 All vxworks based targets now support a user settable option, called
5999 vxworks-timeout. This option represents the number of seconds gdb
6000 should wait for responses to rpc's. You might want to use this if
6001 your vxworks target is, perhaps, a slow software simulator or happens
6002 to be on the far side of a thin network line.
6006 This release contains support for using a DEC alpha as a GDB host for
6007 cross debugging. Native alpha debugging is not supported yet.
6010 *** Changes in GDB-4.9:
6014 This is the first GDB release which is accompanied by a matching testsuite.
6015 The testsuite requires installation of dejagnu, which should be available
6016 via ftp from most sites that carry GNU software.
6020 'Cfront' style demangling has had its name changed to 'ARM' style, to
6021 emphasize that it was written from the specifications in the C++ Annotated
6022 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6023 disclaimers, it still generated too much confusion with users attempting to
6024 use gdb with AT&T cfront.
6028 GDB now uses a standard remote interface to a simulator library.
6029 So far, the library contains simulators for the Zilog Z8001/2, the
6030 Hitachi H8/300, H8/500 and Super-H.
6032 * New targets supported
6034 H8/300 simulator h8300-hitachi-hms or h8300hms
6035 H8/500 simulator h8500-hitachi-hms or h8500hms
6036 SH simulator sh-hitachi-hms or sh
6037 Z8000 simulator z8k-zilog-none or z8ksim
6038 IDT MIPS board over serial line mips-idt-ecoff
6040 Cross-debugging to GO32 targets is supported. It requires a custom
6041 version of the i386-stub.c module which is integrated with the
6042 GO32 memory extender.
6044 * New remote protocols
6046 MIPS remote debugging protocol.
6048 * New source languages supported
6050 This version includes preliminary support for Chill, a Pascal like language
6051 used by telecommunications companies. Chill support is also being integrated
6052 into the GNU compiler, but we don't know when it will be publically available.
6055 *** Changes in GDB-4.8:
6057 * HP Precision Architecture supported
6059 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6060 version of this support was available as a set of patches from the
6061 University of Utah. GDB does not support debugging of programs
6062 compiled with the HP compiler, because HP will not document their file
6063 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6064 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6066 Many problems in the preliminary version have been fixed.
6068 * Faster and better demangling
6070 We have improved template demangling and fixed numerous bugs in the GNU style
6071 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6072 character types (wchar_t) are now supported. Demangling of each symbol is now
6073 only done once, and is cached when the symbol table for a file is read in.
6074 This results in a small increase in memory usage for C programs, a moderate
6075 increase in memory usage for C++ programs, and a fantastic speedup in
6078 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6079 from the specifications in the Annotated Reference Manual, which AT&T's
6080 compiler does not actually implement.
6082 * G++ multiple inheritance compiler problem
6084 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6085 inheritance lattices was reworked to properly discover ambiguities. We
6086 recently found an example which causes this new algorithm to fail in a
6087 very subtle way, producing bad debug information for those classes.
6088 The file 'gcc.patch' (in this directory) can be applied to gcc to
6089 circumvent the problem. A future GCC release will contain a complete
6092 The previous G++ debug info problem (mentioned below for the gdb-4.7
6093 release) is fixed in gcc version 2.3.2.
6095 * Improved configure script
6097 The `configure' script will now attempt to guess your system type if
6098 you don't supply a host system type. The old scheme of supplying a
6099 host system triplet is preferable over using this. All the magic is
6100 done in the new `config.guess' script. Examine it for details.
6102 We have also brought our configure script much more in line with the FSF's
6103 version. It now supports the --with-xxx options. In particular,
6104 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6105 The resulting GDB will not be able to read arbitrary object file formats --
6106 only the format ``expected'' to be used on the configured target system.
6107 We hope to make this the default in a future release.
6109 * Documentation improvements
6111 There's new internal documentation on how to modify GDB, and how to
6112 produce clean changes to the code. We implore people to read it
6113 before submitting changes.
6115 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6116 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6117 `info' files are also provided. To build `info' files from scratch,
6118 you will need the latest `makeinfo' release, which will be available in
6119 a future texinfo-X.Y release.
6121 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6122 We're not sure exactly which versions have this problem, but it has
6123 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6124 or better. If that isn't possible, there is a patch in
6125 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6126 around this problem.
6130 GDB now supports array constants that can be used in expressions typed in by
6131 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6132 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6135 The new directory `gdb/sparclite' contains a program that demonstrates
6136 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6138 * New native hosts supported
6140 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6141 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6143 * New targets supported
6145 AMD 29k family via UDI a29k-amd-udi or udi29k
6147 * New file formats supported
6149 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6150 HPUX core files, and SCO 3.2v2 core files.
6154 Attaching to processes now works again; thanks for the many bug reports.
6156 We have also stomped on a bunch of core dumps caused by
6157 printf_filtered("%s") problems.
6159 We eliminated a copyright problem on the rpc and ptrace header files
6160 for VxWorks, which was discovered at the last minute during the 4.7
6161 release. You should now be able to build a VxWorks GDB.
6163 You can now interrupt gdb while an attached process is running. This
6164 will cause the attached process to stop, and give control back to GDB.
6166 We fixed problems caused by using too many file descriptors
6167 for reading symbols from object files and libraries. This was
6168 especially a problem for programs that used many (~100) shared
6171 The `step' command now only enters a subroutine if there is line number
6172 information for the subroutine. Otherwise it acts like the `next'
6173 command. Previously, `step' would enter subroutines if there was
6174 any debugging information about the routine. This avoids problems
6175 when using `cc -g1' on MIPS machines.
6177 * Internal improvements
6179 GDB's internal interfaces have been improved to make it easier to support
6180 debugging of multiple languages in the future.
6182 GDB now uses a common structure for symbol information internally.
6183 Minimal symbols (derived from linkage symbols in object files), partial
6184 symbols (from a quick scan of debug information), and full symbols
6185 contain a common subset of information, making it easier to write
6186 shared code that handles any of them.
6188 * New command line options
6190 We now accept --silent as an alias for --quiet.
6194 The memory-mapped-malloc library is now licensed under the GNU Library
6195 General Public License.
6197 *** Changes in GDB-4.7:
6199 * Host/native/target split
6201 GDB has had some major internal surgery to untangle the support for
6202 hosts and remote targets. Now, when you configure GDB for a remote
6203 target, it will no longer load in all of the support for debugging
6204 local programs on the host. When fully completed and tested, this will
6205 ensure that arbitrary host/target combinations are possible.
6207 The primary conceptual shift is to separate the non-portable code in
6208 GDB into three categories. Host specific code is required any time GDB
6209 is compiled on that host, regardless of the target. Target specific
6210 code relates to the peculiarities of the target, but can be compiled on
6211 any host. Native specific code is everything else: it can only be
6212 built when the host and target are the same system. Child process
6213 handling and core file support are two common `native' examples.
6215 GDB's use of /proc for controlling Unix child processes is now cleaner.
6216 It has been split out into a single module under the `target_ops' vector,
6217 plus two native-dependent functions for each system that uses /proc.
6219 * New hosts supported
6221 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6222 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6223 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6225 * New targets supported
6227 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6228 68030 and CPU32 m68030-*-*, m68332-*-*
6230 * New native hosts supported
6232 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6233 (386bsd is not well tested yet)
6234 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6236 * New file formats supported
6238 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6239 supports reading of `a.out.adobe' object files, which are an a.out
6240 format extended with minimal information about multiple sections.
6244 `show copying' is the same as the old `info copying'.
6245 `show warranty' is the same as `info warrantee'.
6246 These were renamed for consistency. The old commands continue to work.
6248 `info handle' is a new alias for `info signals'.
6250 You can now define pre-command hooks, which attach arbitrary command
6251 scripts to any command. The commands in the hook will be executed
6252 prior to the user's command. You can also create a hook which will be
6253 executed whenever the program stops. See gdb.texinfo.
6257 We now deal with Cfront style name mangling, and can even extract type
6258 info from mangled symbols. GDB can automatically figure out which
6259 symbol mangling style your C++ compiler uses.
6261 Calling of methods and virtual functions has been improved as well.
6265 The crash that occured when debugging Sun Ansi-C compiled binaries is
6266 fixed. This was due to mishandling of the extra N_SO stabs output
6269 We also finally got Ultrix 4.2 running in house, and fixed core file
6270 support, with help from a dozen people on the net.
6272 John M. Farrell discovered that the reason that single-stepping was so
6273 slow on all of the Mips based platforms (primarily SGI and DEC) was
6274 that we were trying to demangle and lookup a symbol used for internal
6275 purposes on every instruction that was being stepped through. Changing
6276 the name of that symbol so that it couldn't be mistaken for a C++
6277 mangled symbol sped things up a great deal.
6279 Rich Pixley sped up symbol lookups in general by getting much smarter
6280 about when C++ symbol mangling is necessary. This should make symbol
6281 completion (TAB on the command line) much faster. It's not as fast as
6282 we'd like, but it's significantly faster than gdb-4.6.
6286 A new user controllable variable 'call_scratch_address' can
6287 specify the location of a scratch area to be used when GDB
6288 calls a function in the target. This is necessary because the
6289 usual method of putting the scratch area on the stack does not work
6290 in systems that have separate instruction and data spaces.
6292 We integrated changes to support the 29k UDI (Universal Debugger
6293 Interface), but discovered at the last minute that we didn't have all
6294 of the appropriate copyright paperwork. We are working with AMD to
6295 resolve this, and hope to have it available soon.
6299 We have sped up the remote serial line protocol, especially for targets
6300 with lots of registers. It now supports a new `expedited status' ('T')
6301 message which can be used in place of the existing 'S' status message.
6302 This allows the remote stub to send only the registers that GDB
6303 needs to make a quick decision about single-stepping or conditional
6304 breakpoints, eliminating the need to fetch the entire register set for
6305 each instruction being stepped through.
6307 The GDB remote serial protocol now implements a write-through cache for
6308 registers, only re-reading the registers if the target has run.
6310 There is also a new remote serial stub for SPARC processors. You can
6311 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6312 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6313 processor with a serial port.
6317 Configure.in files have become much easier to read and modify. A new
6318 `table driven' format makes it more obvious what configurations are
6319 supported, and what files each one uses.
6323 There is a new opcodes library which will eventually contain all of the
6324 disassembly routines and opcode tables. At present, it only contains
6325 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6326 disassembler (binutils/objdump) to share these routines.
6328 The libiberty library is now copylefted under the GNU Library General
6329 Public License. This allows more liberal use, and was done so libg++
6330 can use it. This makes no difference to GDB, since the Library License
6331 grants all the rights from the General Public License.
6335 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6336 reference to the stabs symbol info used by the debugger. It is (as far
6337 as we know) the only published document on this fascinating topic. We
6338 encourage you to read it, compare it to the stabs information on your
6339 system, and send improvements on the document in general (to
6340 bug-gdb@prep.ai.mit.edu).
6342 And, of course, many bugs have been fixed.
6345 *** Changes in GDB-4.6:
6347 * Better support for C++ function names
6349 GDB now accepts as input the "demangled form" of C++ overloaded function
6350 names and member function names, and can do command completion on such names
6351 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6352 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6353 Make use of command completion, it is your friend.
6355 GDB also now accepts a variety of C++ mangled symbol formats. They are
6356 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6357 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6358 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6359 for the list of formats.
6361 * G++ symbol mangling problem
6363 Recent versions of gcc have a bug in how they emit debugging information for
6364 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6365 directory) can be applied to gcc to fix the problem. Alternatively, if you
6366 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6367 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6368 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6371 * New 'maintenance' command
6373 All of the commands related to hacking GDB internals have been moved out of
6374 the main command set, and now live behind the 'maintenance' command. This
6375 can also be abbreviated as 'mt'. The following changes were made:
6377 dump-me -> maintenance dump-me
6378 info all-breakpoints -> maintenance info breakpoints
6379 printmsyms -> maintenance print msyms
6380 printobjfiles -> maintenance print objfiles
6381 printpsyms -> maintenance print psymbols
6382 printsyms -> maintenance print symbols
6384 The following commands are new:
6386 maintenance demangle Call internal GDB demangler routine to
6387 demangle a C++ link name and prints the result.
6388 maintenance print type Print a type chain for a given symbol
6390 * Change to .gdbinit file processing
6392 We now read the $HOME/.gdbinit file before processing the argv arguments
6393 (e.g. reading symbol files or core files). This allows global parameters to
6394 be set, which will apply during the symbol reading. The ./.gdbinit is still
6395 read after argv processing.
6397 * New hosts supported
6399 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6401 GNU/Linux support i386-unknown-linux or linux
6403 We are also including code to support the HP/PA running BSD and HPUX. This
6404 is almost guaranteed not to work, as we didn't have time to test or build it
6405 for this release. We are including it so that the more adventurous (or
6406 masochistic) of you can play with it. We also had major problems with the
6407 fact that the compiler that we got from HP doesn't support the -g option.
6410 * New targets supported
6412 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6414 * More smarts about finding #include files
6416 GDB now remembers the compilation directory for all include files, and for
6417 all files from which C is generated (like yacc and lex sources). This
6418 greatly improves GDB's ability to find yacc/lex sources, and include files,
6419 especially if you are debugging your program from a directory different from
6420 the one that contains your sources.
6422 We also fixed a bug which caused difficulty with listing and setting
6423 breakpoints in include files which contain C code. (In the past, you had to
6424 try twice in order to list an include file that you hadn't looked at before.)
6426 * Interesting infernals change
6428 GDB now deals with arbitrary numbers of sections, where the symbols for each
6429 section must be relocated relative to that section's landing place in the
6430 target's address space. This work was needed to support ELF with embedded
6431 stabs used by Solaris-2.0.
6433 * Bug fixes (of course!)
6435 There have been loads of fixes for the following things:
6436 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6437 i960, stabs, DOS(GO32), procfs, etc...
6439 See the ChangeLog for details.
6441 *** Changes in GDB-4.5:
6443 * New machines supported (host and target)
6445 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6447 SGI Irix-4.x mips-sgi-irix4 or iris4
6449 * New malloc package
6451 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6452 Mmalloc is capable of handling mutiple heaps of memory. It is also
6453 capable of saving a heap to a file, and then mapping it back in later.
6454 This can be used to greatly speedup the startup of GDB by using a
6455 pre-parsed symbol table which lives in a mmalloc managed heap. For
6456 more details, please read mmalloc/mmalloc.texi.
6460 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6461 'help info proc' for details.
6463 * MIPS ecoff symbol table format
6465 The code that reads MIPS symbol table format is now supported on all hosts.
6466 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6469 * File name changes for MS-DOS
6471 Many files in the config directories have been renamed to make it easier to
6472 support GDB on MS-DOSe systems (which have very restrictive file name
6473 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6474 environment) is close to working but has some remaining problems. Note
6475 that debugging of DOS programs is not supported, due to limitations
6476 in the ``operating system'', but it can be used to host cross-debugging.
6478 * Cross byte order fixes
6480 Many fixes have been made to support cross debugging of Sparc and MIPS
6481 targets from hosts whose byte order differs.
6483 * New -mapped and -readnow options
6485 If memory-mapped files are available on your system through the 'mmap'
6486 system call, you can use the -mapped option on the `file' or
6487 `symbol-file' commands to cause GDB to write the symbols from your
6488 program into a reusable file. If the program you are debugging is
6489 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6490 Future GDB debugging sessions will notice the presence of this file,
6491 and will quickly map in symbol information from it, rather than reading
6492 the symbol table from the executable program. Using the '-mapped'
6493 option in a GDB `file' or `symbol-file' command has the same effect as
6494 starting GDB with the '-mapped' command-line option.
6496 You can cause GDB to read the entire symbol table immediately by using
6497 the '-readnow' option with any of the commands that load symbol table
6498 information (or on the GDB command line). This makes the command
6499 slower, but makes future operations faster.
6501 The -mapped and -readnow options are typically combined in order to
6502 build a `fred.syms' file that contains complete symbol information.
6503 A simple GDB invocation to do nothing but build a `.syms' file for future
6506 gdb -batch -nx -mapped -readnow programname
6508 The `.syms' file is specific to the host machine on which GDB is run.
6509 It holds an exact image of GDB's internal symbol table. It cannot be
6510 shared across multiple host platforms.
6512 * longjmp() handling
6514 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6515 siglongjmp() without losing control. This feature has not yet been ported to
6516 all systems. It currently works on many 386 platforms, all MIPS-based
6517 platforms (SGI, DECstation, etc), and Sun3/4.
6521 Preliminary work has been put in to support the new Solaris OS from Sun. At
6522 this time, it can control and debug processes, but it is not capable of
6527 As always, many many bug fixes. The major areas were with g++, and mipsread.
6528 People using the MIPS-based platforms should experience fewer mysterious
6529 crashes and trashed symbol tables.
6531 *** Changes in GDB-4.4:
6533 * New machines supported (host and target)
6535 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6537 BSD Reno on Vax vax-dec-bsd
6538 Ultrix on Vax vax-dec-ultrix
6540 * New machines supported (target)
6542 AMD 29000 embedded, using EBMON a29k-none-none
6546 GDB continues to improve its handling of C++. `References' work better.
6547 The demangler has also been improved, and now deals with symbols mangled as
6548 per the Annotated C++ Reference Guide.
6550 GDB also now handles `stabs' symbol information embedded in MIPS
6551 `ecoff' symbol tables. Since the ecoff format was not easily
6552 extensible to handle new languages such as C++, this appeared to be a
6553 good way to put C++ debugging info into MIPS binaries. This option
6554 will be supported in the GNU C compiler, version 2, when it is
6557 * New features for SVR4
6559 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6560 shared libraries. Debugging dynamically linked programs should present
6561 only minor differences from debugging statically linked programs.
6563 The `info proc' command will print out information about any process
6564 on an SVR4 system (including the one you are debugging). At the moment,
6565 it prints the address mappings of the process.
6567 If you bring up GDB on another SVR4 system, please send mail to
6568 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6570 * Better dynamic linking support in SunOS
6572 Reading symbols from shared libraries which contain debugging symbols
6573 now works properly. However, there remain issues such as automatic
6574 skipping of `transfer vector' code during function calls, which
6575 make it harder to debug code in a shared library, than to debug the
6576 same code linked statically.
6580 GDB is now using the latest `getopt' routines from the FSF. This
6581 version accepts the -- prefix for options with long names. GDB will
6582 continue to accept the old forms (-option and +option) as well.
6583 Various single letter abbreviations for options have been explicity
6584 added to the option table so that they won't get overshadowed in the
6585 future by other options that begin with the same letter.
6589 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6590 Many assorted bugs have been handled. Many more remain to be handled.
6591 See the various ChangeLog files (primarily in gdb and bfd) for details.
6594 *** Changes in GDB-4.3:
6596 * New machines supported (host and target)
6598 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6599 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6600 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6602 * Almost SCO Unix support
6604 We had hoped to support:
6605 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6606 (except for core file support), but we discovered very late in the release
6607 that it has problems with process groups that render gdb unusable. Sorry
6608 about that. I encourage people to fix it and post the fixes.
6610 * Preliminary ELF and DWARF support
6612 GDB can read ELF object files on System V Release 4, and can handle
6613 debugging records for C, in DWARF format, in ELF files. This support
6614 is preliminary. If you bring up GDB on another SVR4 system, please
6615 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6620 GDB now uses the latest `readline' library. One user-visible change
6621 is that two tabs will list possible command completions, which previously
6622 required typing M-? (meta-question mark, or ESC ?).
6626 The `stepi' bug that many of you noticed has been squashed.
6627 Many bugs in C++ have been handled. Many more remain to be handled.
6628 See the various ChangeLog files (primarily in gdb and bfd) for details.
6630 * State of the MIPS world (in case you wondered):
6632 GDB can understand the symbol tables emitted by the compilers
6633 supplied by most vendors of MIPS-based machines, including DEC. These
6634 symbol tables are in a format that essentially nobody else uses.
6636 Some versions of gcc come with an assembler post-processor called
6637 mips-tfile. This program is required if you want to do source-level
6638 debugging of gcc-compiled programs. I believe FSF does not ship
6639 mips-tfile with gcc version 1, but it will eventually come with gcc
6642 Debugging of g++ output remains a problem. g++ version 1.xx does not
6643 really support it at all. (If you're lucky, you should be able to get
6644 line numbers and stack traces to work, but no parameters or local
6645 variables.) With some work it should be possible to improve the
6648 When gcc version 2 is released, you will have somewhat better luck.
6649 However, even then you will get confusing results for inheritance and
6652 We will eventually provide full debugging of g++ output on
6653 DECstations. This will probably involve some kind of stabs-in-ecoff
6654 encapulation, but the details have not been worked out yet.
6657 *** Changes in GDB-4.2:
6659 * Improved configuration
6661 Only one copy of `configure' exists now, and it is not self-modifying.
6662 Porting BFD is simpler.
6666 The `step' and `next' commands now only stop at the first instruction
6667 of a source line. This prevents the multiple stops that used to occur
6668 in switch statements, for-loops, etc. `Step' continues to stop if a
6669 function that has debugging information is called within the line.
6673 Lots of small bugs fixed. More remain.
6675 * New host supported (not target)
6677 Intel 386 PC clone running Mach i386-none-mach
6680 *** Changes in GDB-4.1:
6682 * Multiple source language support
6684 GDB now has internal scaffolding to handle several source languages.
6685 It determines the type of each source file from its filename extension,
6686 and will switch expression parsing and number formatting to match the
6687 language of the function in the currently selected stack frame.
6688 You can also specifically set the language to be used, with
6689 `set language c' or `set language modula-2'.
6693 GDB now has preliminary support for the GNU Modula-2 compiler,
6694 currently under development at the State University of New York at
6695 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6696 continue through the fall of 1991 and into 1992.
6698 Other Modula-2 compilers are currently not supported, and attempting to
6699 debug programs compiled with them will likely result in an error as the
6700 symbol table is read. Feel free to work on it, though!
6702 There are hooks in GDB for strict type checking and range checking,
6703 in the `Modula-2 philosophy', but they do not currently work.
6707 GDB can now write to executable and core files (e.g. patch
6708 a variable's value). You must turn this switch on, specify
6709 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6710 by assigning a new value to a variable. Modifications take
6713 * Automatic SunOS shared library reading
6715 When you run your program, GDB automatically determines where its
6716 shared libraries (if any) have been loaded, and reads their symbols.
6717 The `share' command is no longer needed. This also works when
6718 examining core files.
6722 You can specify the number of lines that the `list' command shows.
6725 * New machines supported (host and target)
6727 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6728 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6729 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6731 * New hosts supported (not targets)
6733 IBM RT/PC: romp-ibm-aix or rtpc
6735 * New targets supported (not hosts)
6737 AMD 29000 embedded with COFF a29k-none-coff
6738 AMD 29000 embedded with a.out a29k-none-aout
6739 Ultracomputer remote kernel debug a29k-nyu-kern
6741 * New remote interfaces
6747 *** Changes in GDB-4.0:
6751 Wide output is wrapped at good places to make the output more readable.
6753 Gdb now supports cross-debugging from a host machine of one type to a
6754 target machine of another type. Communication with the target system
6755 is over serial lines. The ``target'' command handles connecting to the
6756 remote system; the ``load'' command will download a program into the
6757 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6758 also supports debugging of realtime processes running under VxWorks,
6759 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6760 stub on the target system.
6762 New CPUs supported include the AMD 29000 and Intel 960.
6764 GDB now reads object files and symbol tables via a ``binary file''
6765 library, which allows a single copy of GDB to debug programs of multiple
6766 object file types such as a.out and coff.
6768 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6769 refcard.dvi and refcard.ps are available to format it).
6772 * Control-Variable user interface simplified
6774 All variables that control the operation of the debugger can be set
6775 by the ``set'' command, and displayed by the ``show'' command.
6777 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6778 ``Show prompt'' produces the response:
6779 Gdb's prompt is new-gdb=>.
6781 What follows are the NEW set commands. The command ``help set'' will
6782 print a complete list of old and new set commands. ``help set FOO''
6783 will give a longer description of the variable FOO. ``show'' will show
6784 all of the variable descriptions and their current settings.
6786 confirm on/off: Enables warning questions for operations that are
6787 hard to recover from, e.g. rerunning the program while
6788 it is already running. Default is ON.
6790 editing on/off: Enables EMACS style command line editing
6791 of input. Previous lines can be recalled with
6792 control-P, the current line can be edited with control-B,
6793 you can search for commands with control-R, etc.
6796 history filename NAME: NAME is where the gdb command history
6797 will be stored. The default is .gdb_history,
6798 or the value of the environment variable
6801 history size N: The size, in commands, of the command history. The
6802 default is 256, or the value of the environment variable
6805 history save on/off: If this value is set to ON, the history file will
6806 be saved after exiting gdb. If set to OFF, the
6807 file will not be saved. The default is OFF.
6809 history expansion on/off: If this value is set to ON, then csh-like
6810 history expansion will be performed on
6811 command line input. The default is OFF.
6813 radix N: Sets the default radix for input and output. It can be set
6814 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6815 in the current radix, so "set radix 10" is always a no-op.
6817 height N: This integer value is the number of lines on a page. Default
6818 is 24, the current `stty rows'' setting, or the ``li#''
6819 setting from the termcap entry matching the environment
6822 width N: This integer value is the number of characters on a line.
6823 Default is 80, the current `stty cols'' setting, or the ``co#''
6824 setting from the termcap entry matching the environment
6827 Note: ``set screensize'' is obsolete. Use ``set height'' and
6828 ``set width'' instead.
6830 print address on/off: Print memory addresses in various command displays,
6831 such as stack traces and structure values. Gdb looks
6832 more ``symbolic'' if you turn this off; it looks more
6833 ``machine level'' with it on. Default is ON.
6835 print array on/off: Prettyprint arrays. New convenient format! Default
6838 print demangle on/off: Print C++ symbols in "source" form if on,
6841 print asm-demangle on/off: Same, for assembler level printouts
6844 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6847 * Support for Epoch Environment.
6849 The epoch environment is a version of Emacs v18 with windowing. One
6850 new command, ``inspect'', is identical to ``print'', except that if you
6851 are running in the epoch environment, the value is printed in its own
6855 * Support for Shared Libraries
6857 GDB can now debug programs and core files that use SunOS shared libraries.
6858 Symbols from a shared library cannot be referenced
6859 before the shared library has been linked with the program (this
6860 happens after you type ``run'' and before the function main() is entered).
6861 At any time after this linking (including when examining core files
6862 from dynamically linked programs), gdb reads the symbols from each
6863 shared library when you type the ``sharedlibrary'' command.
6864 It can be abbreviated ``share''.
6866 sharedlibrary REGEXP: Load shared object library symbols for files
6867 matching a unix regular expression. No argument
6868 indicates to load symbols for all shared libraries.
6870 info sharedlibrary: Status of loaded shared libraries.
6875 A watchpoint stops execution of a program whenever the value of an
6876 expression changes. Checking for this slows down execution
6877 tremendously whenever you are in the scope of the expression, but is
6878 quite useful for catching tough ``bit-spreader'' or pointer misuse
6879 problems. Some machines such as the 386 have hardware for doing this
6880 more quickly, and future versions of gdb will use this hardware.
6882 watch EXP: Set a watchpoint (breakpoint) for an expression.
6884 info watchpoints: Information about your watchpoints.
6886 delete N: Deletes watchpoint number N (same as breakpoints).
6887 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6888 enable N: Re-enables watchpoint number N (same as breakpoints).
6891 * C++ multiple inheritance
6893 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6896 * C++ exception handling
6898 Gdb now supports limited C++ exception handling. Besides the existing
6899 ability to breakpoint on an exception handler, gdb can breakpoint on
6900 the raising of an exception (before the stack is peeled back to the
6903 catch FOO: If there is a FOO exception handler in the dynamic scope,
6904 set a breakpoint to catch exceptions which may be raised there.
6905 Multiple exceptions (``catch foo bar baz'') may be caught.
6907 info catch: Lists all exceptions which may be caught in the
6908 current stack frame.
6911 * Minor command changes
6913 The command ``call func (arg, arg, ...)'' now acts like the print
6914 command, except it does not print or save a value if the function's result
6915 is void. This is similar to dbx usage.
6917 The ``up'' and ``down'' commands now always print the frame they end up
6918 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6919 frames without printing.
6921 * New directory command
6923 'dir' now adds directories to the FRONT of the source search path.
6924 The path starts off empty. Source files that contain debug information
6925 about the directory in which they were compiled can be found even
6926 with an empty path; Sun CC and GCC include this information. If GDB can't
6927 find your source file in the current directory, type "dir .".
6929 * Configuring GDB for compilation
6931 For normal use, type ``./configure host''. See README or gdb.texinfo
6934 GDB now handles cross debugging. If you are remotely debugging between
6935 two different machines, type ``./configure host -target=targ''.
6936 Host is the machine where GDB will run; targ is the machine
6937 where the program that you are debugging will run.