1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now uses the GNU MPFR library, if available, to emulate target
7 floating-point arithmetic during expression evaluation when the target
8 uses different floating-point formats than the host. At least version
9 3.1 of GNU MPFR is required.
11 * GDB now supports access to the guarded-storage-control registers and the
12 software-based guarded-storage broadcast control registers on IBM z14.
14 * On Unix systems, GDB now supports transmitting environment variables
15 that are to be set or unset to GDBserver. These variables will
16 affect the environment to be passed to the remote inferior.
18 To inform GDB of environment variables that are to be transmitted to
19 GDBserver, use the "set environment" command. Only user set
20 environment variables are sent to GDBserver.
22 To inform GDB of environment variables that are to be unset before
23 the remote inferior is started by the GDBserver, use the "unset
28 ** New events gdb.new_inferior, gdb.inferior_deleted, and
29 gdb.new_thread are emitted. See the manual for further
32 ** A new command, "rbreak" has been added to the Python API. This
33 command allows the setting of a large number of breakpoints via a
34 regex pattern in Python. See the manual for further details.
36 * New features in the GDB remote stub, GDBserver
38 ** GDBserver is now able to start inferior processes with a
39 specified initial working directory.
41 The user can set the desired working directory to be used from
42 GDB using the new "set cwd" command.
44 ** New "--selftest" command line option runs some GDBserver self
45 tests. These self tests are disabled in releases.
47 ** On Unix systems, GDBserver now does globbing expansion and variable
48 substitution in inferior command line arguments.
50 This is done by starting inferiors using a shell, like GDB does.
51 See "set startup-with-shell" in the user manual for how to disable
52 this from GDB when using "target extended-remote". When using
53 "target remote", you can disable the startup with shell by using the
54 new "--no-startup-with-shell" GDBserver command line option.
56 ** On Unix systems, GDBserver now supports receiving environment
57 variables that are to be set or unset from GDB. These variables
58 will affect the environment to be passed to the inferior.
62 QEnvironmentHexEncoded
63 Inform GDBserver of an environment variable that is to be passed to
64 the inferior when starting it.
67 Inform GDBserver of an environment variable that is to be unset
68 before starting the remote inferior.
71 Inform GDBserver that the environment should be reset (i.e.,
72 user-set environment variables should be unset).
75 Indicates whether the inferior must be started with a shell or not.
78 Tell GDBserver that the inferior to be started should use a specific
81 * The "maintenance print c-tdesc" command now takes an optional
82 argument which is the file name of XML target description.
84 * The "maintenance selftest" command now takes an optional argument to
85 filter the tests to be run.
87 * The "enable", and "disable" commands now accept a range of
88 breakpoint locations, e.g. "enable 1.3-5".
93 Set and show the current working directory for the inferior.
96 Set and show compilation command used for compiling and injecting code
97 with the 'compile' commands.
99 set debug separate-debug-file
100 show debug separate-debug-file
101 Control the display of debug output about separate debug file search.
104 List the registered selftests.
107 Start the debugged program stopping at the first instruction.
109 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
112 * Safer/improved support for debugging with no debug info
114 GDB no longer assumes functions with no debug information return
117 This means that GDB now refuses to call such functions unless you
118 tell it the function's type, by either casting the call to the
119 declared return type, or by casting the function to a function
120 pointer of the right type, and calling that:
122 (gdb) p getenv ("PATH")
123 'getenv' has unknown return type; cast the call to its declared return type
124 (gdb) p (char *) getenv ("PATH")
125 $1 = 0x7fffffffe "/usr/local/bin:/"...
126 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
127 $2 = 0x7fffffffe "/usr/local/bin:/"...
129 Similarly, GDB no longer assumes that global variables with no debug
130 info have type 'int', and refuses to print the variable's value
131 unless you tell it the variable's type:
134 'var' has unknown type; cast it to its declared type
138 * New native configurations
140 FreeBSD/aarch64 aarch64*-*-freebsd*
141 FreeBSD/arm arm*-*-freebsd*
145 FreeBSD/aarch64 aarch64*-*-freebsd*
146 FreeBSD/arm arm*-*-freebsd*
148 * Removed targets and native configurations
150 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
152 *** Changes in GDB 8.0
154 * GDB now supports access to the PKU register on GNU/Linux. The register is
155 added by the Memory Protection Keys for Userspace feature which will be
156 available in future Intel CPUs.
158 * GDB now supports C++11 rvalue references.
162 ** New functions to start, stop and access a running btrace recording.
163 ** Rvalue references are now supported in gdb.Type.
165 * GDB now supports recording and replaying rdrand and rdseed Intel 64
168 * Building GDB and GDBserver now requires a C++11 compiler.
170 For example, GCC 4.8 or later.
172 It is no longer possible to build GDB or GDBserver with a C
173 compiler. The --disable-build-with-cxx configure option has been
176 * Building GDB and GDBserver now requires GNU make >= 3.81.
178 It is no longer supported to build GDB or GDBserver with another
179 implementation of the make program or an earlier version of GNU make.
181 * Native debugging on MS-Windows supports command-line redirection
183 Command-line arguments used for starting programs on MS-Windows can
184 now include redirection symbols supported by native Windows shells,
185 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
186 as "run", "start", and "set args", as well as the corresponding MI
189 * Support for thread names on MS-Windows.
191 GDB now catches and handles the special exception that programs
192 running on MS-Windows use to assign names to threads in the
195 * Support for Java programs compiled with gcj has been removed.
197 * User commands now accept an unlimited number of arguments.
198 Previously, only up to 10 was accepted.
200 * The "eval" command now expands user-defined command arguments.
202 This makes it easier to process a variable number of arguments:
207 eval "print $arg%d", $i
212 * Target descriptions can now describe registers for sparc32 and sparc64.
214 * GDB now supports DWARF version 5 (debug information format).
215 Its .debug_names index is not yet supported.
217 * New native configurations
219 FreeBSD/mips mips*-*-freebsd
223 Synopsys ARC arc*-*-elf32
224 FreeBSD/mips mips*-*-freebsd
226 * Removed targets and native configurations
228 Alpha running FreeBSD alpha*-*-freebsd*
229 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
234 Erases all the flash memory regions reported by the target.
236 maint print arc arc-instruction address
237 Print internal disassembler information about instruction at a given address.
241 set disassembler-options
242 show disassembler-options
243 Controls the passing of target specific information to the disassembler.
244 If it is necessary to specify more than one disassembler option then
245 multiple options can be placed together into a comma separated list.
246 The default value is the empty string. Currently, the only supported
247 targets are ARM, PowerPC and S/390.
252 Erases all the flash memory regions reported by the target. This is
253 equivalent to the CLI command flash-erase.
255 -file-list-shared-libraries
256 List the shared libraries in the program. This is
257 equivalent to the CLI command "info shared".
259 *** Changes in GDB 7.12
261 * GDB and GDBserver now build with a C++ compiler by default.
263 The --enable-build-with-cxx configure option is now enabled by
264 default. One must now explicitly configure with
265 --disable-build-with-cxx in order to build with a C compiler. This
266 option will be removed in a future release.
268 * GDBserver now supports recording btrace without maintaining an active
271 * GDB now supports a negative repeat count in the 'x' command to examine
272 memory backward from the given address. For example:
275 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
276 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
277 (gdb) x/-5i 0x0000000000400580
278 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
279 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
280 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
281 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
282 0x40057b <main(int, char**)+25>:
283 callq 0x400536 <Func1(int, char const*)>
285 * Fortran: Support structures with fields of dynamic types and
286 arrays of dynamic types.
288 * The symbol dumping maintenance commands have new syntax.
289 maint print symbols [-pc address] [--] [filename]
290 maint print symbols [-objfile objfile] [-source source] [--] [filename]
291 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
292 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
293 maint print msymbols [-objfile objfile] [--] [filename]
295 * GDB now supports multibit bitfields and enums in target register
298 * New Python-based convenience function $_as_string(val), which returns
299 the textual representation of a value. This function is especially
300 useful to obtain the text label of an enum value.
302 * Intel MPX bound violation handling.
304 Segmentation faults caused by a Intel MPX boundary violation
305 now display the kind of violation (upper or lower), the memory
306 address accessed and the memory bounds, along with the usual
307 signal received and code location.
311 Program received signal SIGSEGV, Segmentation fault
312 Upper bound violation while accessing address 0x7fffffffc3b3
313 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
314 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
316 * Rust language support.
317 GDB now supports debugging programs written in the Rust programming
318 language. See https://www.rust-lang.org/ for more information about
321 * Support for running interpreters on specified input/output devices
323 GDB now supports a new mechanism that allows frontends to provide
324 fully featured GDB console views, as a better alternative to
325 building such views on top of the "-interpreter-exec console"
326 command. See the new "new-ui" command below. With that command,
327 frontends can now start GDB in the traditional command-line mode
328 running in an embedded terminal emulator widget, and create a
329 separate MI interpreter running on a specified i/o device. In this
330 way, GDB handles line editing, history, tab completion, etc. in the
331 console all by itself, and the GUI uses the separate MI interpreter
332 for its own control and synchronization, invisible to the command
335 * The "catch syscall" command catches groups of related syscalls.
337 The "catch syscall" command now supports catching a group of related
338 syscalls using the 'group:' or 'g:' prefix.
343 skip -gfile file-glob-pattern
344 skip -function function
345 skip -rfunction regular-expression
346 A generalized form of the skip command, with new support for
347 glob-style file names and regular expressions for function names.
348 Additionally, a file spec and a function spec may now be combined.
350 maint info line-table REGEXP
351 Display the contents of GDB's internal line table data struture.
354 Run any GDB unit tests that were compiled in.
357 Start a new user interface instance running INTERP as interpreter,
358 using the TTY file for input/output.
362 ** gdb.Breakpoint objects have a new attribute "pending", which
363 indicates whether the breakpoint is pending.
364 ** Three new breakpoint-related events have been added:
365 gdb.breakpoint_created, gdb.breakpoint_modified, and
366 gdb.breakpoint_deleted.
369 Signal ("set") the given MS-Windows event object. This is used in
370 conjunction with the Windows JIT debugging (AeDebug) support, where
371 the OS suspends a crashing process until a debugger can attach to
372 it. Resuming the crashing process, in order to debug it, is done by
375 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
376 was added in GDBserver, including JIT compiling fast tracepoint's
377 conditional expression bytecode into native code.
379 * Support for various remote target protocols and ROM monitors has
382 target m32rsdi Remote M32R debugging over SDI
383 target mips MIPS remote debugging protocol
384 target pmon PMON ROM monitor
385 target ddb NEC's DDB variant of PMON for Vr4300
386 target rockhopper NEC RockHopper variant of PMON
387 target lsi LSI variant of PMO
389 * Support for tracepoints and fast tracepoints on powerpc-linux,
390 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
391 including JIT compiling fast tracepoint's conditional expression
392 bytecode into native code.
394 * MI async record =record-started now includes the method and format used for
395 recording. For example:
397 =record-started,thread-group="i1",method="btrace",format="bts"
399 * MI async record =thread-selected now includes the frame field. For example:
401 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
405 Andes NDS32 nds32*-*-elf
407 *** Changes in GDB 7.11
409 * GDB now supports debugging kernel-based threads on FreeBSD.
411 * Per-inferior thread numbers
413 Thread numbers are now per inferior instead of global. If you're
414 debugging multiple inferiors, GDB displays thread IDs using a
415 qualified INF_NUM.THR_NUM form. For example:
419 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
420 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
421 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
422 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
424 As consequence, thread numbers as visible in the $_thread
425 convenience variable and in Python's InferiorThread.num attribute
426 are no longer unique between inferiors.
428 GDB now maintains a second thread ID per thread, referred to as the
429 global thread ID, which is the new equivalent of thread numbers in
430 previous releases. See also $_gthread below.
432 For backwards compatibility, MI's thread IDs always refer to global
435 * Commands that accept thread IDs now accept the qualified
436 INF_NUM.THR_NUM form as well. For example:
439 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
442 * In commands that accept a list of thread IDs, you can now refer to
443 all threads of an inferior using a star wildcard. GDB accepts
444 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
445 refer to all threads of the current inferior. For example, "info
448 * You can use "info threads -gid" to display the global thread ID of
451 * The new convenience variable $_gthread holds the global number of
454 * The new convenience variable $_inferior holds the number of the
457 * GDB now displays the ID and name of the thread that hit a breakpoint
458 or received a signal, if your program is multi-threaded. For
461 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
462 Thread 1 "main" received signal SIGINT, Interrupt.
464 * Record btrace now supports non-stop mode.
466 * Support for tracepoints on aarch64-linux was added in GDBserver.
468 * The 'record instruction-history' command now indicates speculative execution
469 when using the Intel Processor Trace recording format.
471 * GDB now allows users to specify explicit locations, bypassing
472 the linespec parser. This feature is also available to GDB/MI
475 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
476 GDB now is able to debug both AArch64 applications and ARM applications
479 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
480 including JIT compiling fast tracepoint's conditional expression bytecode
483 * GDB now supports displaced stepping on AArch64 GNU/Linux.
485 * "info threads", "info inferiors", "info display", "info checkpoints"
486 and "maint info program-spaces" now list the corresponding items in
487 ascending ID order, for consistency with all other "info" commands.
489 * In Ada, the overloads selection menu has been enhanced to display the
490 parameter types and the return types for the matching overloaded subprograms.
494 maint set target-non-stop (on|off|auto)
495 maint show target-non-stop
496 Control whether GDB targets always operate in non-stop mode even if
497 "set non-stop" is "off". The default is "auto", meaning non-stop
498 mode is enabled if supported by the target.
500 maint set bfd-sharing
501 maint show bfd-sharing
502 Control the reuse of bfd objects.
506 Control display of debugging info regarding bfd caching.
510 Control display of debugging info regarding FreeBSD threads.
512 set remote multiprocess-extensions-packet
513 show remote multiprocess-extensions-packet
514 Set/show the use of the remote protocol multiprocess extensions.
516 set remote thread-events
517 show remote thread-events
518 Set/show the use of thread create/exit events.
520 set ada print-signatures on|off
521 show ada print-signatures"
522 Control whether parameter types and return types are displayed in overloads
523 selection menus. It is activaled (@code{on}) by default.
527 Controls the maximum size of memory, in bytes, that GDB will
528 allocate for value contents. Prevents incorrect programs from
529 causing GDB to allocate overly large buffers. Default is 64k.
531 * The "disassemble" command accepts a new modifier: /s.
532 It prints mixed source+disassembly like /m with two differences:
533 - disassembled instructions are now printed in program order, and
534 - and source for all relevant files is now printed.
535 The "/m" option is now considered deprecated: its "source-centric"
536 output hasn't proved useful in practice.
538 * The "record instruction-history" command accepts a new modifier: /s.
539 It behaves exactly like /m and prints mixed source+disassembly.
541 * The "set scheduler-locking" command supports a new mode "replay".
542 It behaves like "off" in record mode and like "on" in replay mode.
544 * Support for various ROM monitors has been removed:
546 target dbug dBUG ROM monitor for Motorola ColdFire
547 target picobug Motorola picobug monitor
548 target dink32 DINK32 ROM monitor for PowerPC
549 target m32r Renesas M32R/D ROM monitor
550 target mon2000 mon2000 ROM monitor
551 target ppcbug PPCBUG ROM monitor for PowerPC
553 * Support for reading/writing memory and extracting values on architectures
554 whose memory is addressable in units of any integral multiple of 8 bits.
559 Indicates that an exec system call was executed.
561 exec-events feature in qSupported
562 The qSupported packet allows GDB to request support for exec
563 events using the new 'gdbfeature' exec-event, and the qSupported
564 response can contain the corresponding 'stubfeature'. Set and
565 show commands can be used to display whether these features are enabled.
568 Equivalent to interrupting with the ^C character, but works in
571 thread created stop reason (T05 create:...)
572 Indicates that the thread was just created and is stopped at entry.
574 thread exit stop reply (w exitcode;tid)
575 Indicates that the thread has terminated.
578 Enables/disables thread create and exit event reporting. For
579 example, this is used in non-stop mode when GDB stops a set of
580 threads and synchronously waits for the their corresponding stop
581 replies. Without exit events, if one of the threads exits, GDB
582 would hang forever not knowing that it should no longer expect a
583 stop for that same thread.
586 Indicates that there are no resumed threads left in the target (all
587 threads are stopped). The remote stub reports support for this stop
588 reply to GDB's qSupported query.
591 Enables/disables catching syscalls from the inferior process.
592 The remote stub reports support for this packet to GDB's qSupported query.
594 syscall_entry stop reason
595 Indicates that a syscall was just called.
597 syscall_return stop reason
598 Indicates that a syscall just returned.
600 * Extended-remote exec events
602 ** GDB now has support for exec events on extended-remote Linux targets.
603 For such targets with Linux kernels 2.5.46 and later, this enables
604 follow-exec-mode and exec catchpoints.
606 set remote exec-event-feature-packet
607 show remote exec-event-feature-packet
608 Set/show the use of the remote exec event feature.
610 * Thread names in remote protocol
612 The reply to qXfer:threads:read may now include a name attribute for each
615 * Target remote mode fork and exec events
617 ** GDB now has support for fork and exec events on target remote mode
618 Linux targets. For such targets with Linux kernels 2.5.46 and later,
619 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
620 fork and exec catchpoints.
622 * Remote syscall events
624 ** GDB now has support for catch syscall on remote Linux targets,
625 currently enabled on x86/x86_64 architectures.
627 set remote catch-syscall-packet
628 show remote catch-syscall-packet
629 Set/show the use of the remote catch syscall feature.
633 ** The -var-set-format command now accepts the zero-hexadecimal
634 format. It outputs data in hexadecimal format with zero-padding on the
639 ** gdb.InferiorThread objects have a new attribute "global_num",
640 which refers to the thread's global thread ID. The existing
641 "num" attribute now refers to the thread's per-inferior number.
642 See "Per-inferior thread numbers" above.
643 ** gdb.InferiorThread objects have a new attribute "inferior", which
644 is the Inferior object the thread belongs to.
646 *** Changes in GDB 7.10
648 * Support for process record-replay and reverse debugging on aarch64*-linux*
649 targets has been added. GDB now supports recording of A64 instruction set
650 including advance SIMD instructions.
652 * Support for Sun's version of the "stabs" debug file format has been removed.
654 * GDB now honors the content of the file /proc/PID/coredump_filter
655 (PID is the process ID) on GNU/Linux systems. This file can be used
656 to specify the types of memory mappings that will be included in a
657 corefile. For more information, please refer to the manual page of
658 "core(5)". GDB also has a new command: "set use-coredump-filter
659 on|off". It allows to set whether GDB will read the content of the
660 /proc/PID/coredump_filter file when generating a corefile.
662 * The "info os" command on GNU/Linux can now display information on
664 "info os cpus" Listing of all cpus/cores on the system
666 * GDB has two new commands: "set serial parity odd|even|none" and
667 "show serial parity". These allows to set or show parity for the
670 * The "info source" command now displays the producer string if it was
671 present in the debug info. This typically includes the compiler version
672 and may include things like its command line arguments.
674 * The "info dll", an alias of the "info sharedlibrary" command,
675 is now available on all platforms.
677 * Directory names supplied to the "set sysroot" commands may be
678 prefixed with "target:" to tell GDB to access shared libraries from
679 the target system, be it local or remote. This replaces the prefix
680 "remote:". The default sysroot has been changed from "" to
681 "target:". "remote:" is automatically converted to "target:" for
682 backward compatibility.
684 * The system root specified by "set sysroot" will be prepended to the
685 filename of the main executable (if reported to GDB as absolute by
686 the operating system) when starting processes remotely, and when
687 attaching to already-running local or remote processes.
689 * GDB now supports automatic location and retrieval of executable
690 files from remote targets. Remote debugging can now be initiated
691 using only a "target remote" or "target extended-remote" command
692 (no "set sysroot" or "file" commands are required). See "New remote
695 * The "dump" command now supports verilog hex format.
697 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
699 * On GNU/Linux, GDB and gdbserver are now able to access executable
700 and shared library files without a "set sysroot" command when
701 attaching to processes running in different mount namespaces from
702 the debugger. This makes it possible to attach to processes in
703 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
704 See "New remote packets" below.
706 * The "tui reg" command now provides completion for all of the
707 available register groups, including target specific groups.
709 * The HISTSIZE environment variable is no longer read when determining
710 the size of GDB's command history. GDB now instead reads the dedicated
711 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
712 disables truncation of command history. Non-numeric values of GDBHISTSIZE
717 ** Memory ports can now be unbuffered.
721 ** gdb.Objfile objects have a new attribute "username",
722 which is the name of the objfile as specified by the user,
723 without, for example, resolving symlinks.
724 ** You can now write frame unwinders in Python.
725 ** gdb.Type objects have a new method "optimized_out",
726 returning optimized out gdb.Value instance of this type.
727 ** gdb.Value objects have new methods "reference_value" and
728 "const_value" which return a reference to the value and a
729 "const" version of the value respectively.
733 maint print symbol-cache
734 Print the contents of the symbol cache.
736 maint print symbol-cache-statistics
737 Print statistics of symbol cache usage.
739 maint flush-symbol-cache
740 Flush the contents of the symbol cache.
744 Start branch trace recording using Branch Trace Store (BTS) format.
747 Evaluate expression by using the compiler and print result.
751 Explicit commands for enabling and disabling tui mode.
754 set mpx bound on i386 and amd64
755 Support for bound table investigation on Intel MPX enabled applications.
759 Start branch trace recording using Intel Processor Trace format.
762 Print information about branch tracing internals.
764 maint btrace packet-history
765 Print the raw branch tracing data.
767 maint btrace clear-packet-history
768 Discard the stored raw branch tracing data.
771 Discard all branch tracing data. It will be fetched and processed
772 anew by the next "record" command.
777 Renamed from "set debug dwarf2-die".
779 Renamed from "show debug dwarf2-die".
782 Renamed from "set debug dwarf2-read".
783 show debug dwarf-read
784 Renamed from "show debug dwarf2-read".
786 maint set dwarf always-disassemble
787 Renamed from "maint set dwarf2 always-disassemble".
788 maint show dwarf always-disassemble
789 Renamed from "maint show dwarf2 always-disassemble".
791 maint set dwarf max-cache-age
792 Renamed from "maint set dwarf2 max-cache-age".
793 maint show dwarf max-cache-age
794 Renamed from "maint show dwarf2 max-cache-age".
797 show debug dwarf-line
798 Control display of debugging info regarding DWARF line processing.
802 Set the maximum number of candidates to be considered during
803 completion. The default value is 200. This limit allows GDB
804 to avoid generating large completion lists, the computation of
805 which can cause the debugger to become temporarily unresponsive.
807 set history remove-duplicates
808 show history remove-duplicates
809 Control the removal of duplicate history entries.
811 maint set symbol-cache-size
812 maint show symbol-cache-size
813 Control the size of the symbol cache.
815 set|show record btrace bts buffer-size
816 Set and show the size of the ring buffer used for branch tracing in
818 The obtained size may differ from the requested size. Use "info
819 record" to see the obtained buffer size.
821 set debug linux-namespaces
822 show debug linux-namespaces
823 Control display of debugging info regarding Linux namespaces.
825 set|show record btrace pt buffer-size
826 Set and show the size of the ring buffer used for branch tracing in
827 Intel Processor Trace format.
828 The obtained size may differ from the requested size. Use "info
829 record" to see the obtained buffer size.
831 maint set|show btrace pt skip-pad
832 Set and show whether PAD packets are skipped when computing the
835 * The command 'thread apply all' can now support new option '-ascending'
836 to call its specified command for all threads in ascending order.
838 * Python/Guile scripting
840 ** GDB now supports auto-loading of Python/Guile scripts contained in the
841 special section named `.debug_gdb_scripts'.
845 qXfer:btrace-conf:read
846 Return the branch trace configuration for the current thread.
848 Qbtrace-conf:bts:size
849 Set the requested ring buffer size for branch tracing in BTS format.
852 Enable Intel Procesor Trace-based branch tracing for the current
853 process. The remote stub reports support for this packet to GDB's
857 Set the requested ring buffer size for branch tracing in Intel Processor
861 Indicates a memory breakpoint instruction was executed, irrespective
862 of whether it was GDB that planted the breakpoint or the breakpoint
863 is hardcoded in the program. This is required for correct non-stop
867 Indicates the target stopped for a hardware breakpoint. This is
868 required for correct non-stop mode operation.
871 Return information about files on the remote system.
874 Return the full absolute name of the file that was executed to
875 create a process running on the remote system.
878 Select the filesystem on which vFile: operations with filename
879 arguments will operate. This is required for GDB to be able to
880 access files on remote targets where the remote stub does not
881 share a common filesystem with the inferior(s).
884 Indicates that a fork system call was executed.
887 Indicates that a vfork system call was executed.
889 vforkdone stop reason
890 Indicates that a vfork child of the specified process has executed
891 an exec or exit, allowing the vfork parent to resume execution.
893 fork-events and vfork-events features in qSupported
894 The qSupported packet allows GDB to request support for fork and
895 vfork events using new 'gdbfeatures' fork-events and vfork-events,
896 and the qSupported response can contain the corresponding
897 'stubfeatures'. Set and show commands can be used to display
898 whether these features are enabled.
900 * Extended-remote fork events
902 ** GDB now has support for fork events on extended-remote Linux
903 targets. For targets with Linux kernels 2.5.60 and later, this
904 enables follow-fork-mode and detach-on-fork for both fork and
905 vfork, as well as fork and vfork catchpoints.
907 * The info record command now shows the recording format and the
908 branch tracing configuration for the current thread when using
909 the btrace record target.
910 For the BTS format, it shows the ring buffer size.
912 * GDB now has support for DTrace USDT (Userland Static Defined
913 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
915 * GDB now supports access to vector registers on S/390 GNU/Linux
918 * Removed command line options
920 -xdb HP-UX XDB compatibility mode.
922 * Removed targets and native configurations
924 HP/PA running HP-UX hppa*-*-hpux*
925 Itanium running HP-UX ia64-*-hpux*
927 * New configure options
930 This configure option allows the user to build GDB with support for
931 Intel Processor Trace (default: auto). This requires libipt.
933 --with-libipt-prefix=PATH
934 Specify the path to the version of libipt that GDB should use.
935 $PATH/include should contain the intel-pt.h header and
936 $PATH/lib should contain the libipt.so library.
938 *** Changes in GDB 7.9.1
942 ** Xmethods can now specify a result type.
944 *** Changes in GDB 7.9
946 * GDB now supports hardware watchpoints on x86 GNU Hurd.
950 ** You can now access frame registers from Python scripts.
951 ** New attribute 'producer' for gdb.Symtab objects.
952 ** gdb.Objfile objects have a new attribute "progspace",
953 which is the gdb.Progspace object of the containing program space.
954 ** gdb.Objfile objects have a new attribute "owner".
955 ** gdb.Objfile objects have a new attribute "build_id",
956 which is the build ID generated when the file was built.
957 ** gdb.Objfile objects have a new method "add_separate_debug_file".
958 ** A new event "gdb.clear_objfiles" has been added, triggered when
959 selecting a new file to debug.
960 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
961 ** New function gdb.lookup_objfile.
963 New events which are triggered when GDB modifies the state of the
966 ** gdb.events.inferior_call_pre: Function call is about to be made.
967 ** gdb.events.inferior_call_post: Function call has just been made.
968 ** gdb.events.memory_changed: A memory location has been altered.
969 ** gdb.events.register_changed: A register has been altered.
971 * New Python-based convenience functions:
973 ** $_caller_is(name [, number_of_frames])
974 ** $_caller_matches(regexp [, number_of_frames])
975 ** $_any_caller_is(name [, number_of_frames])
976 ** $_any_caller_matches(regexp [, number_of_frames])
978 * GDB now supports the compilation and injection of source code into
979 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
980 to compile the source code to object code, and if successful, inject
981 and execute that code within the current context of the inferior.
982 Currently the C language is supported. The commands used to
983 interface with this new feature are:
985 compile code [-raw|-r] [--] [source code]
986 compile file [-raw|-r] filename
990 demangle [-l language] [--] name
991 Demangle "name" in the specified language, or the current language
992 if elided. This command is renamed from the "maint demangle" command.
993 The latter is kept as a no-op to avoid "maint demangle" being interpreted
994 as "maint demangler-warning".
996 queue-signal signal-name-or-number
997 Queue a signal to be delivered to the thread when it is resumed.
999 add-auto-load-scripts-directory directory
1000 Add entries to the list of directories from which to load auto-loaded
1003 maint print user-registers
1004 List all currently available "user" registers.
1006 compile code [-r|-raw] [--] [source code]
1007 Compile, inject, and execute in the inferior the executable object
1008 code produced by compiling the provided source code.
1010 compile file [-r|-raw] filename
1011 Compile and inject into the inferior the executable object code
1012 produced by compiling the source code stored in the filename
1015 * On resume, GDB now always passes the signal the program had stopped
1016 for to the thread the signal was sent to, even if the user changed
1017 threads before resuming. Previously GDB would often (but not
1018 always) deliver the signal to the thread that happens to be current
1021 * Conversely, the "signal" command now consistently delivers the
1022 requested signal to the current thread. GDB now asks for
1023 confirmation if the program had stopped for a signal and the user
1024 switched threads meanwhile.
1026 * "breakpoint always-inserted" modes "off" and "auto" merged.
1028 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1029 won't remove breakpoints from the target until all threads stop,
1030 even in non-stop mode. The "auto" mode has been removed, and "off"
1031 is now the default mode.
1035 set debug symbol-lookup
1036 show debug symbol-lookup
1037 Control display of debugging info regarding symbol lookup.
1041 ** The -list-thread-groups command outputs an exit-code field for
1042 inferiors that have exited.
1046 MIPS SDE mips*-sde*-elf*
1050 Support for these obsolete configurations has been removed.
1052 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1053 SGI Irix-5.x mips-*-irix5*
1054 SGI Irix-6.x mips-*-irix6*
1055 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1056 VAX running Ultrix vax-*-ultrix*
1058 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1059 and "assf"), have been removed. Use the "sharedlibrary" command, or
1060 its alias "share", instead.
1062 *** Changes in GDB 7.8
1064 * New command line options
1067 This is an alias for the --data-directory option.
1069 * GDB supports printing and modifying of variable length automatic arrays
1070 as specified in ISO C99.
1072 * The ARM simulator now supports instruction level tracing
1073 with or without disassembly.
1077 GDB now has support for scripting using Guile. Whether this is
1078 available is determined at configure time.
1079 Guile version 2.0 or greater is required.
1080 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1082 * New commands (for set/show, see "New options" below)
1086 Invoke CODE by passing it to the Guile interpreter.
1090 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1092 info auto-load guile-scripts [regexp]
1093 Print the list of automatically loaded Guile scripts.
1095 * The source command is now capable of sourcing Guile scripts.
1096 This feature is dependent on the debugger being built with Guile support.
1100 set print symbol-loading (off|brief|full)
1101 show print symbol-loading
1102 Control whether to print informational messages when loading symbol
1103 information for a file. The default is "full", but when debugging
1104 programs with large numbers of shared libraries the amount of output
1105 becomes less useful.
1107 set guile print-stack (none|message|full)
1108 show guile print-stack
1109 Show a stack trace when an error is encountered in a Guile script.
1111 set auto-load guile-scripts (on|off)
1112 show auto-load guile-scripts
1113 Control auto-loading of Guile script files.
1115 maint ada set ignore-descriptive-types (on|off)
1116 maint ada show ignore-descriptive-types
1117 Control whether the debugger should ignore descriptive types in Ada
1118 programs. The default is not to ignore the descriptive types. See
1119 the user manual for more details on descriptive types and the intended
1120 usage of this option.
1122 set auto-connect-native-target
1124 Control whether GDB is allowed to automatically connect to the
1125 native target for the run, attach, etc. commands when not connected
1126 to any target yet. See also "target native" below.
1128 set record btrace replay-memory-access (read-only|read-write)
1129 show record btrace replay-memory-access
1130 Control what memory accesses are allowed during replay.
1132 maint set target-async (on|off)
1133 maint show target-async
1134 This controls whether GDB targets operate in synchronous or
1135 asynchronous mode. Normally the default is asynchronous, if it is
1136 available; but this can be changed to more easily debug problems
1137 occurring only in synchronous mode.
1139 set mi-async (on|off)
1141 Control whether MI asynchronous mode is preferred. This supersedes
1142 "set target-async" of previous GDB versions.
1144 * "set target-async" is deprecated as a CLI option and is now an alias
1145 for "set mi-async" (only puts MI into async mode).
1147 * Background execution commands (e.g., "c&", "s&", etc.) are now
1148 possible ``out of the box'' if the target supports them. Previously
1149 the user would need to explicitly enable the possibility with the
1150 "set target-async on" command.
1152 * New features in the GDB remote stub, GDBserver
1154 ** New option --debug-format=option1[,option2,...] allows one to add
1155 additional text to each output. At present only timestamps
1156 are supported: --debug-format=timestamps.
1157 Timestamps can also be turned on with the
1158 "monitor set debug-format timestamps" command from GDB.
1160 * The 'record instruction-history' command now starts counting instructions
1161 at one. This also affects the instruction ranges reported by the
1162 'record function-call-history' command when given the /i modifier.
1164 * The command 'record function-call-history' supports a new modifier '/c' to
1165 indent the function names based on their call stack depth.
1166 The fields for the '/i' and '/l' modifier have been reordered.
1167 The source line range is now prefixed with 'at'.
1168 The instruction range is now prefixed with 'inst'.
1169 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1170 "record instruction-history" and "list" commands.
1172 * The ranges given as arguments to the 'record function-call-history' and
1173 'record instruction-history' commands are now inclusive.
1175 * The btrace record target now supports the 'record goto' command.
1176 For locations inside the execution trace, the back trace is computed
1177 based on the information stored in the execution trace.
1179 * The btrace record target supports limited reverse execution and replay.
1180 The target does not record data and therefore does not allow reading
1181 memory or registers.
1183 * The "catch syscall" command now works on s390*-linux* targets.
1185 * The "compare-sections" command is no longer specific to target
1186 remote. It now works with all targets.
1188 * All native targets are now consistently called "native".
1189 Consequently, the "target child", "target GNU", "target djgpp",
1190 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1191 commands have been replaced with "target native". The QNX/NTO port
1192 leaves the "procfs" target in place and adds a "native" target for
1193 consistency with other ports. The impact on users should be minimal
1194 as these commands previously either throwed an error, or were
1195 no-ops. The target's name is visible in the output of the following
1196 commands: "help target", "info target", "info files", "maint print
1199 * The "target native" command now connects to the native target. This
1200 can be used to launch native programs even when "set
1201 auto-connect-native-target" is set to off.
1203 * GDB now supports access to Intel MPX registers on GNU/Linux.
1205 * Support for Intel AVX-512 registers on GNU/Linux.
1206 Support displaying and modifying Intel AVX-512 registers
1207 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1209 * New remote packets
1211 qXfer:btrace:read's annex
1212 The qXfer:btrace:read packet supports a new annex 'delta' to read
1213 branch trace incrementally.
1217 ** Valid Python operations on gdb.Value objects representing
1218 structs/classes invoke the corresponding overloaded operators if
1220 ** New `Xmethods' feature in the Python API. Xmethods are
1221 additional methods or replacements for existing methods of a C++
1222 class. This feature is useful for those cases where a method
1223 defined in C++ source code could be inlined or optimized out by
1224 the compiler, making it unavailable to GDB.
1227 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1229 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1230 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1231 its alias "share", instead.
1233 * The commands "set remotebaud" and "show remotebaud" are no longer
1234 supported. Use "set serial baud" and "show serial baud" (respectively)
1239 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1240 target-async". The latter is left as a deprecated alias of the
1241 former for backward compatibility. If the target supports it,
1242 CLI background execution commands are now always possible by
1243 default, independently of whether the frontend stated a
1244 preference for asynchronous execution with "-gdb-set mi-async".
1245 Previously "-gdb-set target-async off" affected both MI execution
1246 commands and CLI execution commands.
1248 *** Changes in GDB 7.7
1250 * Improved support for process record-replay and reverse debugging on
1251 arm*-linux* targets. Support for thumb32 and syscall instruction
1252 recording has been added.
1254 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1256 * GDB now supports Fission DWP file format version 2.
1257 http://gcc.gnu.org/wiki/DebugFission
1259 * New convenience function "$_isvoid", to check whether an expression
1260 is void. A void expression is an expression where the type of the
1261 result is "void". For example, some convenience variables may be
1262 "void" when evaluated (e.g., "$_exitcode" before the execution of
1263 the program being debugged; or an undefined convenience variable).
1264 Another example, when calling a function whose return type is
1267 * The "maintenance print objfiles" command now takes an optional regexp.
1269 * The "catch syscall" command now works on arm*-linux* targets.
1271 * GDB now consistently shows "<not saved>" when printing values of
1272 registers the debug info indicates have not been saved in the frame
1273 and there's nowhere to retrieve them from
1274 (callee-saved/call-clobbered registers):
1279 (gdb) info registers rax
1282 Before, the former would print "<optimized out>", and the latter
1283 "*value not available*".
1285 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1290 ** Frame filters and frame decorators have been added.
1291 ** Temporary breakpoints are now supported.
1292 ** Line tables representation has been added.
1293 ** New attribute 'parent_type' for gdb.Field objects.
1294 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1295 ** New attribute 'name' for gdb.Type objects.
1299 Nios II ELF nios2*-*-elf
1300 Nios II GNU/Linux nios2*-*-linux
1301 Texas Instruments MSP430 msp430*-*-elf
1303 * Removed native configurations
1305 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1306 been removed. ELF variants of these configurations are kept supported.
1308 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1309 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1310 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1311 i[34567]86-*-openbsd3.[0-3]
1312 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1313 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1314 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1318 Like "catch throw", but catches a re-thrown exception.
1319 maint check-psymtabs
1320 Renamed from old "maint check-symtabs".
1322 Perform consistency checks on symtabs.
1323 maint expand-symtabs
1324 Expand symtabs matching an optional regexp.
1327 Display the details of GDB configure-time options.
1329 maint set|show per-command
1330 maint set|show per-command space
1331 maint set|show per-command time
1332 maint set|show per-command symtab
1333 Enable display of per-command gdb resource usage.
1335 remove-symbol-file FILENAME
1336 remove-symbol-file -a ADDRESS
1337 Remove a symbol file added via add-symbol-file. The file to remove
1338 can be identified by its filename or by an address that lies within
1339 the boundaries of this symbol file in memory.
1342 info exceptions REGEXP
1343 Display the list of Ada exceptions defined in the program being
1344 debugged. If provided, only the exceptions whose names match REGEXP
1349 set debug symfile off|on
1351 Control display of debugging info regarding reading symbol files and
1352 symbol tables within those files
1354 set print raw frame-arguments
1355 show print raw frame-arguments
1356 Set/show whether to print frame arguments in raw mode,
1357 disregarding any defined pretty-printers.
1359 set remote trace-status-packet
1360 show remote trace-status-packet
1361 Set/show the use of remote protocol qTStatus packet.
1365 Control display of debugging messages related to Nios II targets.
1369 Control whether target-assisted range stepping is enabled.
1371 set startup-with-shell
1372 show startup-with-shell
1373 Specifies whether Unix child processes are started via a shell or
1378 Use the target memory cache for accesses to the code segment. This
1379 improves performance of remote debugging (particularly disassembly).
1381 * You can now use a literal value 'unlimited' for options that
1382 interpret 0 or -1 as meaning "unlimited". E.g., "set
1383 trace-buffer-size unlimited" is now an alias for "set
1384 trace-buffer-size -1" and "set height unlimited" is now an alias for
1387 * The "set debug symtab-create" debugging option of GDB has been changed to
1388 accept a verbosity level. 0 means "off", 1 provides basic debugging
1389 output, and values of 2 or greater provides more verbose output.
1391 * New command-line options
1393 Display the details of GDB configure-time options.
1395 * The command 'tsave' can now support new option '-ctf' to save trace
1396 buffer in Common Trace Format.
1398 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1401 * GDB now implements the the C++ 'typeid' operator.
1403 * The new convenience variable $_exception holds the exception being
1404 thrown or caught at an exception-related catchpoint.
1406 * The exception-related catchpoints, like "catch throw", now accept a
1407 regular expression which can be used to filter exceptions by type.
1409 * The new convenience variable $_exitsignal is automatically set to
1410 the terminating signal number when the program being debugged dies
1411 due to an uncaught signal.
1415 ** All MI commands now accept an optional "--language" option.
1416 Support for this feature can be verified by using the "-list-features"
1417 command, which should contain "language-option".
1419 ** The new command -info-gdb-mi-command allows the user to determine
1420 whether a GDB/MI command is supported or not.
1422 ** The "^error" result record returned when trying to execute an undefined
1423 GDB/MI command now provides a variable named "code" whose content is the
1424 "undefined-command" error code. Support for this feature can be verified
1425 by using the "-list-features" command, which should contain
1426 "undefined-command-error-code".
1428 ** The -trace-save MI command can optionally save trace buffer in Common
1431 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1433 ** The command -data-list-register-values now accepts an optional
1434 "--skip-unavailable" option. When used, only the available registers
1437 ** The new command -trace-frame-collected dumps collected variables,
1438 computed expressions, tvars, memory and registers in a traceframe.
1440 ** The commands -stack-list-locals, -stack-list-arguments and
1441 -stack-list-variables now accept an option "--skip-unavailable".
1442 When used, only the available locals or arguments are displayed.
1444 ** The -exec-run command now accepts an optional "--start" option.
1445 When used, the command follows the same semantics as the "start"
1446 command, stopping the program's execution at the start of its
1447 main subprogram. Support for this feature can be verified using
1448 the "-list-features" command, which should contain
1449 "exec-run-start-option".
1451 ** The new commands -catch-assert and -catch-exceptions insert
1452 catchpoints stopping the program when Ada exceptions are raised.
1454 ** The new command -info-ada-exceptions provides the equivalent of
1455 the new "info exceptions" command.
1457 * New system-wide configuration scripts
1458 A GDB installation now provides scripts suitable for use as system-wide
1459 configuration scripts for the following systems:
1463 * GDB now supports target-assigned range stepping with remote targets.
1464 This improves the performance of stepping source lines by reducing
1465 the number of control packets from/to GDB. See "New remote packets"
1468 * GDB now understands the element 'tvar' in the XML traceframe info.
1469 It has the id of the collected trace state variables.
1471 * On S/390 targets that provide the transactional-execution feature,
1472 the program interruption transaction diagnostic block (TDB) is now
1473 represented as a number of additional "registers" in GDB.
1475 * New remote packets
1479 The vCont packet supports a new 'r' action, that tells the remote
1480 stub to step through an address range itself, without GDB
1481 involvemement at each single-step.
1483 qXfer:libraries-svr4:read's annex
1484 The previously unused annex of the qXfer:libraries-svr4:read packet
1485 is now used to support passing an argument list. The remote stub
1486 reports support for this argument list to GDB's qSupported query.
1487 The defined arguments are "start" and "prev", used to reduce work
1488 necessary for library list updating, resulting in significant
1491 * New features in the GDB remote stub, GDBserver
1493 ** GDBserver now supports target-assisted range stepping. Currently
1494 enabled on x86/x86_64 GNU/Linux targets.
1496 ** GDBserver now adds element 'tvar' in the XML in the reply to
1497 'qXfer:traceframe-info:read'. It has the id of the collected
1498 trace state variables.
1500 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1503 * New 'z' formatter for printing and examining memory, this displays the
1504 value as hexadecimal zero padded on the left to the size of the type.
1506 * GDB can now use Windows x64 unwinding data.
1508 * The "set remotebaud" command has been replaced by "set serial baud".
1509 Similarly, "show remotebaud" has been replaced by "show serial baud".
1510 The "set remotebaud" and "show remotebaud" commands are still available
1511 to provide backward compatibility with older versions of GDB.
1513 *** Changes in GDB 7.6
1515 * Target record has been renamed to record-full.
1516 Record/replay is now enabled with the "record full" command.
1517 This also affects settings that are associated with full record/replay
1518 that have been moved from "set/show record" to "set/show record full":
1520 set|show record full insn-number-max
1521 set|show record full stop-at-limit
1522 set|show record full memory-query
1524 * A new record target "record-btrace" has been added. The new target
1525 uses hardware support to record the control-flow of a process. It
1526 does not support replaying the execution, but it implements the
1527 below new commands for investigating the recorded execution log.
1528 This new recording method can be enabled using:
1532 The "record-btrace" target is only available on Intel Atom processors
1533 and requires a Linux kernel 2.6.32 or later.
1535 * Two new commands have been added for record/replay to give information
1536 about the recorded execution without having to replay the execution.
1537 The commands are only supported by "record btrace".
1539 record instruction-history prints the execution history at
1540 instruction granularity
1542 record function-call-history prints the execution history at
1543 function granularity
1545 * New native configurations
1547 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1548 FreeBSD/powerpc powerpc*-*-freebsd
1549 x86_64/Cygwin x86_64-*-cygwin*
1550 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1554 ARM AArch64 aarch64*-*-elf
1555 ARM AArch64 GNU/Linux aarch64*-*-linux
1556 Lynx 178 PowerPC powerpc-*-lynx*178
1557 x86_64/Cygwin x86_64-*-cygwin*
1558 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1560 * If the configured location of system.gdbinit file (as given by the
1561 --with-system-gdbinit option at configure time) is in the
1562 data-directory (as specified by --with-gdb-datadir at configure
1563 time) or in one of its subdirectories, then GDB will look for the
1564 system-wide init file in the directory specified by the
1565 --data-directory command-line option.
1567 * New command line options:
1569 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1570 other initialization files, unlike -nx which disables all of them.
1572 * Removed command line options
1574 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1577 * The 'ptype' and 'whatis' commands now accept an argument to control
1580 * 'info proc' now works on some core files.
1584 ** Vectors can be created with gdb.Type.vector.
1586 ** Python's atexit.register now works in GDB.
1588 ** Types can be pretty-printed via a Python API.
1590 ** Python 3 is now supported (in addition to Python 2.4 or later)
1592 ** New class gdb.Architecture exposes GDB's internal representation
1593 of architecture in the Python API.
1595 ** New method Frame.architecture returns the gdb.Architecture object
1596 corresponding to the frame's architecture.
1598 * New Python-based convenience functions:
1600 ** $_memeq(buf1, buf2, length)
1601 ** $_streq(str1, str2)
1603 ** $_regex(str, regex)
1605 * The 'cd' command now defaults to using '~' (the home directory) if not
1608 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1609 default for GCC since November 2000.
1611 * The command 'forward-search' can now be abbreviated as 'fo'.
1613 * The command 'info tracepoints' can now display 'installed on target'
1614 or 'not installed on target' for each non-pending location of tracepoint.
1616 * New configure options
1618 --enable-libmcheck/--disable-libmcheck
1619 By default, development versions are built with -lmcheck on hosts
1620 that support it, in order to help track memory corruption issues.
1621 Release versions, on the other hand, are built without -lmcheck
1622 by default. The --enable-libmcheck/--disable-libmcheck configure
1623 options allow the user to override that default.
1624 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1625 This configure option allows the user to build GDB with
1626 libbabeltrace using which GDB can read Common Trace Format data.
1628 * New commands (for set/show, see "New options" below)
1631 Catch signals. This is similar to "handle", but allows commands and
1632 conditions to be attached.
1635 List the BFDs known to GDB.
1637 python-interactive [command]
1639 Start a Python interactive prompt, or evaluate the optional command
1640 and print the result of expressions.
1643 "py" is a new alias for "python".
1645 enable type-printer [name]...
1646 disable type-printer [name]...
1647 Enable or disable type printers.
1651 ** For the Renesas Super-H architecture, the "regs" command has been removed
1652 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1657 set print type methods (on|off)
1658 show print type methods
1659 Control whether method declarations are displayed by "ptype".
1660 The default is to show them.
1662 set print type typedefs (on|off)
1663 show print type typedefs
1664 Control whether typedef definitions are displayed by "ptype".
1665 The default is to show them.
1667 set filename-display basename|relative|absolute
1668 show filename-display
1669 Control the way in which filenames is displayed.
1670 The default is "relative", which preserves previous behavior.
1672 set trace-buffer-size
1673 show trace-buffer-size
1674 Request target to change the size of trace buffer.
1676 set remote trace-buffer-size-packet auto|on|off
1677 show remote trace-buffer-size-packet
1678 Control the use of the remote protocol `QTBuffer:size' packet.
1682 Control display of debugging messages related to ARM AArch64.
1685 set debug coff-pe-read
1686 show debug coff-pe-read
1687 Control display of debugging messages related to reading of COFF/PE
1692 Control display of debugging messages related to Mach-O symbols
1695 set debug notification
1696 show debug notification
1697 Control display of debugging info for async remote notification.
1701 ** Command parameter changes are now notified using new async record
1702 "=cmd-param-changed".
1703 ** Trace frame changes caused by command "tfind" are now notified using
1704 new async record "=traceframe-changed".
1705 ** The creation, deletion and modification of trace state variables
1706 are now notified using new async records "=tsv-created",
1707 "=tsv-deleted" and "=tsv-modified".
1708 ** The start and stop of process record are now notified using new
1709 async record "=record-started" and "=record-stopped".
1710 ** Memory changes are now notified using new async record
1712 ** The data-disassemble command response will include a "fullname" field
1713 containing the absolute file name when source has been requested.
1714 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1715 command, to allow pattern filling of memory areas.
1716 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1717 library load/unload events.
1718 ** The response to breakpoint commands and breakpoint async records
1719 includes an "installed" field containing a boolean state about each
1720 non-pending tracepoint location is whether installed on target or not.
1721 ** Output of the "-trace-status" command includes a "trace-file" field
1722 containing the name of the trace file being examined. This field is
1723 optional, and only present when examining a trace file.
1724 ** The "fullname" field is now always present along with the "file" field,
1725 even if the file cannot be found by GDB.
1727 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1728 You must have the LZMA library available when configuring GDB for this
1729 feature to be enabled. For more information, see:
1730 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1732 * New remote packets
1735 Set the size of trace buffer. The remote stub reports support for this
1736 packet to gdb's qSupported query.
1739 Enable Branch Trace Store (BTS)-based branch tracing for the current
1740 thread. The remote stub reports support for this packet to gdb's
1744 Disable branch tracing for the current thread. The remote stub reports
1745 support for this packet to gdb's qSupported query.
1748 Read the traced branches for the current thread. The remote stub
1749 reports support for this packet to gdb's qSupported query.
1751 *** Changes in GDB 7.5
1753 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1754 for more x32 ABI info.
1756 * GDB now supports access to MIPS DSP registers on Linux targets.
1758 * GDB now supports debugging microMIPS binaries.
1760 * The "info os" command on GNU/Linux can now display information on
1761 several new classes of objects managed by the operating system:
1762 "info os procgroups" lists process groups
1763 "info os files" lists file descriptors
1764 "info os sockets" lists internet-domain sockets
1765 "info os shm" lists shared-memory regions
1766 "info os semaphores" lists semaphores
1767 "info os msg" lists message queues
1768 "info os modules" lists loaded kernel modules
1770 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1771 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1772 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1773 options and inspect the probe arguments using the new $_probe_arg family
1774 of convenience variables. You can obtain more information about SystemTap
1775 in <http://sourceware.org/systemtap/>.
1777 * GDB now supports reversible debugging on ARM, it allows you to
1778 debug basic ARM and THUMB instructions, and provides
1779 record/replay support.
1781 * The option "symbol-reloading" has been deleted as it is no longer used.
1785 ** GDB commands implemented in Python can now be put in command class
1788 ** The "maint set python print-stack on|off" is now deleted.
1790 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1791 apply "flag enum"-style pretty-printing to any enum.
1793 ** gdb.lookup_symbol can now work when there is no current frame.
1795 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1796 the source at which the symbol was defined.
1798 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1799 method 'value'. The former indicates whether the symbol needs a
1800 frame in order to compute its value, and the latter computes the
1803 ** A new method 'referenced_value' on gdb.Value objects which can
1804 dereference pointer as well as C++ reference values.
1806 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1807 which return the global and static blocks (as gdb.Block objects),
1808 of the underlying symbol table, respectively.
1810 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1811 object associated with a PC value.
1813 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1814 of the address range occupied by code for the current source line.
1816 * Go language support.
1817 GDB now supports debugging programs written in the Go programming
1820 * GDBserver now supports stdio connections.
1821 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1823 * The binary "gdbtui" can no longer be built or installed.
1824 Use "gdb -tui" instead.
1826 * GDB will now print "flag" enums specially. A flag enum is one where
1827 all the enumerator values have no bits in common when pairwise
1828 "and"ed. When printing a value whose type is a flag enum, GDB will
1829 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1830 (gdb) print (enum E) 3
1833 * The filename part of a linespec will now match trailing components
1834 of a source file name. For example, "break gcc/expr.c:1000" will
1835 now set a breakpoint in build/gcc/expr.c, but not
1836 build/libcpp/expr.c.
1838 * The "info proc" and "generate-core-file" commands will now also
1839 work on remote targets connected to GDBserver on Linux.
1841 * The command "info catch" has been removed. It has been disabled
1842 since December 2007.
1844 * The "catch exception" and "catch assert" commands now accept
1845 a condition at the end of the command, much like the "break"
1846 command does. For instance:
1848 (gdb) catch exception Constraint_Error if Barrier = True
1850 Previously, it was possible to add a condition to such catchpoints,
1851 but it had to be done as a second step, after the catchpoint had been
1852 created, using the "condition" command.
1854 * The "info static-tracepoint-marker" command will now also work on
1855 native Linux targets with in-process agent.
1857 * GDB can now set breakpoints on inlined functions.
1859 * The .gdb_index section has been updated to include symbols for
1860 inlined functions. GDB will ignore older .gdb_index sections by
1861 default, which could cause symbol files to be loaded more slowly
1862 until their .gdb_index sections can be recreated. The new command
1863 "set use-deprecated-index-sections on" will cause GDB to use any older
1864 .gdb_index sections it finds. This will restore performance, but the
1865 ability to set breakpoints on inlined functions will be lost in symbol
1866 files with older .gdb_index sections.
1868 The .gdb_index section has also been updated to record more information
1869 about each symbol. This speeds up the "info variables", "info functions"
1870 and "info types" commands when used with programs having the .gdb_index
1871 section, as well as speeding up debugging with shared libraries using
1872 the .gdb_index section.
1874 * Ada support for GDB/MI Variable Objects has been added.
1876 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1881 ** New command -info-os is the MI equivalent of "info os".
1883 ** Output logs ("set logging" and related) now include MI output.
1887 ** "set use-deprecated-index-sections on|off"
1888 "show use-deprecated-index-sections on|off"
1889 Controls the use of deprecated .gdb_index sections.
1891 ** "catch load" and "catch unload" can be used to stop when a shared
1892 library is loaded or unloaded, respectively.
1894 ** "enable count" can be used to auto-disable a breakpoint after
1897 ** "info vtbl" can be used to show the virtual method tables for
1898 C++ and Java objects.
1900 ** "explore" and its sub commands "explore value" and "explore type"
1901 can be used to recursively explore values and types of
1902 expressions. These commands are available only if GDB is
1903 configured with '--with-python'.
1905 ** "info auto-load" shows status of all kinds of auto-loaded files,
1906 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1907 sequences of commands files, "info auto-load python-scripts"
1908 shows status of auto-loading Python script files,
1909 "info auto-load local-gdbinit" shows status of loading init file
1910 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1911 status of inferior specific thread debugging shared library loading.
1913 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1914 and "show auto-load-scripts" commands have been deprecated, use their
1915 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1916 and "show auto-load python-scripts" counterparts instead.
1918 ** "dprintf location,format,args..." creates a dynamic printf, which
1919 is basically a breakpoint that does a printf and immediately
1920 resumes your program's execution, so it is like a printf that you
1921 can insert dynamically at runtime instead of at compiletime.
1923 ** "set print symbol"
1925 Controls whether GDB attempts to display the symbol, if any,
1926 corresponding to addresses it prints. This defaults to "on", but
1927 you can set it to "off" to restore GDB's previous behavior.
1929 * Deprecated commands
1931 ** For the Renesas Super-H architecture, the "regs" command has been
1932 deprecated, and "info all-registers" should be used instead.
1936 Renesas RL78 rl78-*-elf
1937 HP OpenVMS ia64 ia64-hp-openvms*
1939 * GDBserver supports evaluation of breakpoint conditions. When
1940 support is advertised by GDBserver, GDB may be told to send the
1941 breakpoint conditions in bytecode form to GDBserver. GDBserver
1942 will only report the breakpoint trigger to GDB when its condition
1947 set mips compression
1948 show mips compression
1949 Select the compressed ISA encoding used in functions that have no symbol
1950 information available. The encoding can be set to either of:
1953 and is updated automatically from ELF file flags if available.
1955 set breakpoint condition-evaluation
1956 show breakpoint condition-evaluation
1957 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1958 GDBserver ("target"). Default option "auto" chooses the most efficient
1960 This option can improve debugger efficiency depending on the speed of the
1964 Disable auto-loading globally.
1967 Show auto-loading setting of all kinds of auto-loaded files.
1969 set auto-load gdb-scripts on|off
1970 show auto-load gdb-scripts
1971 Control auto-loading of GDB canned sequences of commands files.
1973 set auto-load python-scripts on|off
1974 show auto-load python-scripts
1975 Control auto-loading of Python script files.
1977 set auto-load local-gdbinit on|off
1978 show auto-load local-gdbinit
1979 Control loading of init file (.gdbinit) from current directory.
1981 set auto-load libthread-db on|off
1982 show auto-load libthread-db
1983 Control auto-loading of inferior specific thread debugging shared library.
1985 set auto-load scripts-directory <dir1>[:<dir2>...]
1986 show auto-load scripts-directory
1987 Set a list of directories from which to load auto-loaded scripts.
1988 Automatically loaded Python scripts and GDB scripts are located in one
1989 of the directories listed by this option.
1990 The delimiter (':' above) may differ according to the host platform.
1992 set auto-load safe-path <dir1>[:<dir2>...]
1993 show auto-load safe-path
1994 Set a list of directories from which it is safe to auto-load files.
1995 The delimiter (':' above) may differ according to the host platform.
1997 set debug auto-load on|off
1998 show debug auto-load
1999 Control display of debugging info for auto-loading the files above.
2001 set dprintf-style gdb|call|agent
2003 Control the way in which a dynamic printf is performed; "gdb"
2004 requests a GDB printf command, while "call" causes dprintf to call a
2005 function in the inferior. "agent" requests that the target agent
2006 (such as GDBserver) do the printing.
2008 set dprintf-function <expr>
2009 show dprintf-function
2010 set dprintf-channel <expr>
2011 show dprintf-channel
2012 Set the function and optional first argument to the call when using
2013 the "call" style of dynamic printf.
2015 set disconnected-dprintf on|off
2016 show disconnected-dprintf
2017 Control whether agent-style dynamic printfs continue to be in effect
2018 after GDB disconnects.
2020 * New configure options
2022 --with-auto-load-dir
2023 Configure default value for the 'set auto-load scripts-directory'
2024 setting above. It defaults to '$debugdir:$datadir/auto-load',
2025 $debugdir representing global debugging info directories (available
2026 via 'show debug-file-directory') and $datadir representing GDB's data
2027 directory (available via 'show data-directory').
2029 --with-auto-load-safe-path
2030 Configure default value for the 'set auto-load safe-path' setting
2031 above. It defaults to the --with-auto-load-dir setting.
2033 --without-auto-load-safe-path
2034 Set 'set auto-load safe-path' to '/', effectively disabling this
2037 * New remote packets
2039 z0/z1 conditional breakpoints extension
2041 The z0/z1 breakpoint insertion packets have been extended to carry
2042 a list of conditional expressions over to the remote stub depending on the
2043 condition evaluation mode. The use of this extension can be controlled
2044 via the "set remote conditional-breakpoints-packet" command.
2048 Specify the signals which the remote stub may pass to the debugged
2049 program without GDB involvement.
2051 * New command line options
2053 --init-command=FILE, -ix Like --command, -x but execute it
2054 before loading inferior.
2055 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2056 execute it before loading inferior.
2058 *** Changes in GDB 7.4
2060 * GDB now handles ambiguous linespecs more consistently; the existing
2061 FILE:LINE support has been expanded to other types of linespecs. A
2062 breakpoint will now be set on all matching locations in all
2063 inferiors, and locations will be added or removed according to
2066 * GDB now allows you to skip uninteresting functions and files when
2067 stepping with the "skip function" and "skip file" commands.
2069 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2070 and "show remote hardware-watchpoint-length-limit". These allows to
2071 set or show the maximum length limit (in bytes) of a remote
2072 target hardware watchpoint.
2074 This allows e.g. to use "unlimited" hardware watchpoints with the
2075 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2076 watchpoints are slower than real hardware watchpoints but are
2077 significantly faster than gdb software watchpoints.
2081 ** The register_pretty_printer function in module gdb.printing now takes
2082 an optional `replace' argument. If True, the new printer replaces any
2085 ** The "maint set python print-stack on|off" command has been
2086 deprecated and will be deleted in GDB 7.5.
2087 A new command: "set python print-stack none|full|message" has
2088 replaced it. Additionally, the default for "print-stack" is
2089 now "message", which just prints the error message without
2092 ** A prompt substitution hook (prompt_hook) is now available to the
2095 ** A new Python module, gdb.prompt has been added to the GDB Python
2096 modules library. This module provides functionality for
2097 escape sequences in prompts (used by set/show
2098 extended-prompt). These escape sequences are replaced by their
2099 corresponding value.
2101 ** Python commands and convenience-functions located in
2102 'data-directory'/python/gdb/command and
2103 'data-directory'/python/gdb/function are now automatically loaded
2106 ** Blocks now provide four new attributes. global_block and
2107 static_block will return the global and static blocks
2108 respectively. is_static and is_global are boolean attributes
2109 that indicate if the block is one of those two types.
2111 ** Symbols now provide the "type" attribute, the type of the symbol.
2113 ** The "gdb.breakpoint" function has been deprecated in favor of
2116 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2117 of a function. This class is based on the "finish" command
2118 available in the CLI.
2120 ** Type objects for struct and union types now allow access to
2121 the fields using standard Python dictionary (mapping) methods.
2122 For example, "some_type['myfield']" now works, as does
2123 "some_type.items()".
2125 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2128 ** A new function, "deep_items" has been added to the gdb.types
2129 module in the GDB Python modules library. This function returns
2130 an iterator over the fields of a struct or union type. Unlike
2131 the standard Python "iteritems" method, it will recursively traverse
2132 any anonymous fields.
2136 ** "*stopped" events can report several new "reason"s, such as
2139 ** Breakpoint changes are now notified using new async records, like
2140 "=breakpoint-modified".
2142 ** New command -ada-task-info.
2144 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2145 $sdir specifies the default system locations of shared libraries.
2146 $pdir specifies the directory where the libpthread used by the application
2149 GDB no longer looks in $sdir and $pdir after it has searched the directories
2150 mentioned in libthread-db-search-path. If you want to search those
2151 directories, they must be specified in libthread-db-search-path.
2152 The default value of libthread-db-search-path on GNU/Linux and Solaris
2153 systems is now "$sdir:$pdir".
2155 $pdir is not supported by gdbserver, it is currently ignored.
2156 $sdir is supported by gdbserver.
2158 * New configure option --with-iconv-bin.
2159 When using the internationalization support like the one in the GNU C
2160 library, GDB will invoke the "iconv" program to get a list of supported
2161 character sets. If this program lives in a non-standard location, one can
2162 use this option to specify where to find it.
2164 * When natively debugging programs on PowerPC BookE processors running
2165 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2166 watchpoints, which specify a mask in addition to an address to watch.
2167 The mask specifies that some bits of an address (the bits which are
2168 reset in the mask) should be ignored when matching the address accessed
2169 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2170 section in the user manual for more details.
2172 * The new option --once causes GDBserver to stop listening for connections once
2173 the first connection is made. The listening port used by GDBserver will
2174 become available after that.
2176 * New commands "info macros" and "alias" have been added.
2178 * New function parameters suffix @entry specifies value of function parameter
2179 at the time the function got called. Entry values are available only since
2185 "!" is now an alias of the "shell" command.
2186 Note that no space is needed between "!" and SHELL COMMAND.
2190 watch EXPRESSION mask MASK_VALUE
2191 The watch command now supports the mask argument which allows creation
2192 of masked watchpoints, if the current architecture supports this feature.
2194 info auto-load-scripts [REGEXP]
2195 This command was formerly named "maintenance print section-scripts".
2196 It is now generally useful and is no longer a maintenance-only command.
2198 info macro [-all] [--] MACRO
2199 The info macro command has new options `-all' and `--'. The first for
2200 printing all definitions of a macro. The second for explicitly specifying
2201 the end of arguments and the beginning of the macro name in case the macro
2202 name starts with a hyphen.
2204 collect[/s] EXPRESSIONS
2205 The tracepoint collect command now takes an optional modifier "/s"
2206 that directs it to dereference pointer-to-character types and
2207 collect the bytes of memory up to a zero byte. The behavior is
2208 similar to what you see when you use the regular print command on a
2209 string. An optional integer following the "/s" sets a bound on the
2210 number of bytes that will be collected.
2213 The trace start command now interprets any supplied arguments as a
2214 note to be recorded with the trace run, with an effect similar to
2215 setting the variable trace-notes.
2218 The trace stop command now interprets any arguments as a note to be
2219 mentioned along with the tstatus report that the trace was stopped
2220 with a command. The effect is similar to setting the variable
2223 * Tracepoints can now be enabled and disabled at any time after a trace
2224 experiment has been started using the standard "enable" and "disable"
2225 commands. It is now possible to start a trace experiment with no enabled
2226 tracepoints; GDB will display a warning, but will allow the experiment to
2227 begin, assuming that tracepoints will be enabled as needed while the trace
2230 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2231 locations with 4-byte instructions, when they were previously
2232 limited to locations with instructions of 5 bytes or longer.
2236 set debug dwarf2-read
2237 show debug dwarf2-read
2238 Turns on or off display of debugging messages related to reading
2239 DWARF debug info. The default is off.
2241 set debug symtab-create
2242 show debug symtab-create
2243 Turns on or off display of debugging messages related to symbol table
2244 creation. The default is off.
2247 show extended-prompt
2248 Set the GDB prompt, and allow escape sequences to be inserted to
2249 display miscellaneous information (see 'help set extended-prompt'
2250 for the list of sequences). This prompt (and any information
2251 accessed through the escape sequences) is updated every time the
2252 prompt is displayed.
2254 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2255 show print entry-values
2256 Set printing of frame argument values at function entry. In some cases
2257 GDB can determine the value of function argument which was passed by the
2258 function caller, even if the value was modified inside the called function.
2260 set debug entry-values
2261 show debug entry-values
2262 Control display of debugging info for determining frame argument values at
2263 function entry and virtual tail call frames.
2265 set basenames-may-differ
2266 show basenames-may-differ
2267 Set whether a source file may have multiple base names.
2268 (A "base name" is the name of a file with the directory part removed.
2269 Example: The base name of "/home/user/hello.c" is "hello.c".)
2270 If set, GDB will canonicalize file names (e.g., expand symlinks)
2271 before comparing them. Canonicalization is an expensive operation,
2272 but it allows the same file be known by more than one base name.
2273 If not set (the default), all source files are assumed to have just
2274 one base name, and gdb will do file name comparisons more efficiently.
2280 Set a user name and notes for the current and any future trace runs.
2281 This is useful for long-running and/or disconnected traces, to
2282 inform others (or yourself) as to who is running the trace, supply
2283 contact information, or otherwise explain what is going on.
2285 set trace-stop-notes
2286 show trace-stop-notes
2287 Set a note attached to the trace run, that is displayed when the
2288 trace has been stopped by a tstop command. This is useful for
2289 instance as an explanation, if you are stopping a trace run that was
2290 started by someone else.
2292 * New remote packets
2296 Dynamically enable a tracepoint in a started trace experiment.
2300 Dynamically disable a tracepoint in a started trace experiment.
2304 Set the user and notes of the trace run.
2308 Query the current status of a tracepoint.
2312 Query the minimum length of instruction at which a fast tracepoint may
2315 * Dcache size (number of lines) and line-size are now runtime-configurable
2316 via "set dcache line" and "set dcache line-size" commands.
2320 Texas Instruments TMS320C6x tic6x-*-*
2324 Renesas RL78 rl78-*-elf
2326 *** Changes in GDB 7.3.1
2328 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2330 *** Changes in GDB 7.3
2332 * GDB has a new command: "thread find [REGEXP]".
2333 It finds the thread id whose name, target id, or thread extra info
2334 matches the given regular expression.
2336 * The "catch syscall" command now works on mips*-linux* targets.
2338 * The -data-disassemble MI command now supports modes 2 and 3 for
2339 dumping the instruction opcodes.
2341 * New command line options
2343 -data-directory DIR Specify DIR as the "data-directory".
2344 This is mostly for testing purposes.
2346 * The "maint set python auto-load on|off" command has been renamed to
2347 "set auto-load-scripts on|off".
2349 * GDB has a new command: "set directories".
2350 It is like the "dir" command except that it replaces the
2351 source path list instead of augmenting it.
2353 * GDB now understands thread names.
2355 On GNU/Linux, "info threads" will display the thread name as set by
2356 prctl or pthread_setname_np.
2358 There is also a new command, "thread name", which can be used to
2359 assign a name internally for GDB to display.
2362 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2363 has been integrated into GDB.
2367 ** The function gdb.Write now accepts an optional keyword 'stream'.
2368 This keyword, when provided, will direct the output to either
2369 stdout, stderr, or GDB's logging output.
2371 ** Parameters can now be be sub-classed in Python, and in particular
2372 you may implement the get_set_doc and get_show_doc functions.
2373 This improves how Parameter set/show documentation is processed
2374 and allows for more dynamic content.
2376 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2377 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2378 have an is_valid method.
2380 ** Breakpoints can now be sub-classed in Python, and in particular
2381 you may implement a 'stop' function that is executed each time
2382 the inferior reaches that breakpoint.
2384 ** New function gdb.lookup_global_symbol looks up a global symbol.
2386 ** GDB values in Python are now callable if the value represents a
2387 function. For example, if 'some_value' represents a function that
2388 takes two integer parameters and returns a value, you can call
2389 that function like so:
2391 result = some_value (10,20)
2393 ** Module gdb.types has been added.
2394 It contains a collection of utilities for working with gdb.Types objects:
2395 get_basic_type, has_field, make_enum_dict.
2397 ** Module gdb.printing has been added.
2398 It contains utilities for writing and registering pretty-printers.
2399 New classes: PrettyPrinter, SubPrettyPrinter,
2400 RegexpCollectionPrettyPrinter.
2401 New function: register_pretty_printer.
2403 ** New commands "info pretty-printers", "enable pretty-printer" and
2404 "disable pretty-printer" have been added.
2406 ** gdb.parameter("directories") is now available.
2408 ** New function gdb.newest_frame returns the newest frame in the
2411 ** The gdb.InferiorThread class has a new "name" attribute. This
2412 holds the thread's name.
2414 ** Python Support for Inferior events.
2415 Python scripts can add observers to be notified of events
2416 occurring in the process being debugged.
2417 The following events are currently supported:
2418 - gdb.events.cont Continue event.
2419 - gdb.events.exited Inferior exited event.
2420 - gdb.events.stop Signal received, and Breakpoint hit events.
2424 ** GDB now puts template parameters in scope when debugging in an
2425 instantiation. For example, if you have:
2427 template<int X> int func (void) { return X; }
2429 then if you step into func<5>, "print X" will show "5". This
2430 feature requires proper debuginfo support from the compiler; it
2431 was added to GCC 4.5.
2433 ** The motion commands "next", "finish", "until", and "advance" now
2434 work better when exceptions are thrown. In particular, GDB will
2435 no longer lose control of the inferior; instead, the GDB will
2436 stop the inferior at the point at which the exception is caught.
2437 This functionality requires a change in the exception handling
2438 code that was introduced in GCC 4.5.
2440 * GDB now follows GCC's rules on accessing volatile objects when
2441 reading or writing target state during expression evaluation.
2442 One notable difference to prior behavior is that "print x = 0"
2443 no longer generates a read of x; the value of the assignment is
2444 now always taken directly from the value being assigned.
2446 * GDB now has some support for using labels in the program's source in
2447 linespecs. For instance, you can use "advance label" to continue
2448 execution to a label.
2450 * GDB now has support for reading and writing a new .gdb_index
2451 section. This section holds a fast index of DWARF debugging
2452 information and can be used to greatly speed up GDB startup and
2453 operation. See the documentation for `save gdb-index' for details.
2455 * The "watch" command now accepts an optional "-location" argument.
2456 When used, this causes GDB to watch the memory referred to by the
2457 expression. Such a watchpoint is never deleted due to it going out
2460 * GDB now supports thread debugging of core dumps on GNU/Linux.
2462 GDB now activates thread debugging using the libthread_db library
2463 when debugging GNU/Linux core dumps, similarly to when debugging
2464 live processes. As a result, when debugging a core dump file, GDB
2465 is now able to display pthread_t ids of threads. For example, "info
2466 threads" shows the same output as when debugging the process when it
2467 was live. In earlier releases, you'd see something like this:
2470 * 1 LWP 6780 main () at main.c:10
2472 While now you see this:
2475 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2477 It is also now possible to inspect TLS variables when debugging core
2480 When debugging a core dump generated on a machine other than the one
2481 used to run GDB, you may need to point GDB at the correct
2482 libthread_db library with the "set libthread-db-search-path"
2483 command. See the user manual for more details on this command.
2485 * When natively debugging programs on PowerPC BookE processors running
2486 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2487 which stop execution of the inferior whenever it executes an instruction
2488 at any address within the specified range. See the "PowerPC Embedded"
2489 section in the user manual for more details.
2491 * New features in the GDB remote stub, GDBserver
2493 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2494 and i686 LynxOS (version 5.x).
2496 ** GDBserver is now supported on Blackfin Linux.
2498 * New native configurations
2500 ia64 HP-UX ia64-*-hpux*
2504 Analog Devices, Inc. Blackfin Processor bfin-*
2506 * Ada task switching is now supported on sparc-elf targets when
2507 debugging a program using the Ravenscar Profile. For more information,
2508 see the "Tasking Support when using the Ravenscar Profile" section
2509 in the GDB user manual.
2511 * Guile support was removed.
2513 * New features in the GNU simulator
2515 ** The --map-info flag lists all known core mappings.
2517 ** CFI flashes may be simulated via the "cfi" device.
2519 *** Changes in GDB 7.2
2521 * Shared library support for remote targets by default
2523 When GDB is configured for a generic, non-OS specific target, like
2524 for example, --target=arm-eabi or one of the many *-*-elf targets,
2525 GDB now queries remote stubs for loaded shared libraries using the
2526 `qXfer:libraries:read' packet. Previously, shared library support
2527 was always disabled for such configurations.
2531 ** Argument Dependent Lookup (ADL)
2533 In C++ ADL lookup directs function search to the namespaces of its
2534 arguments even if the namespace has not been imported.
2544 Here the compiler will search for `foo' in the namespace of 'b'
2545 and find A::foo. GDB now supports this. This construct is commonly
2546 used in the Standard Template Library for operators.
2548 ** Improved User Defined Operator Support
2550 In addition to member operators, GDB now supports lookup of operators
2551 defined in a namespace and imported with a `using' directive, operators
2552 defined in the global scope, operators imported implicitly from an
2553 anonymous namespace, and the ADL operators mentioned in the previous
2555 GDB now also supports proper overload resolution for all the previously
2556 mentioned flavors of operators.
2558 ** static const class members
2560 Printing of static const class members that are initialized in the
2561 class definition has been fixed.
2563 * Windows Thread Information Block access.
2565 On Windows targets, GDB now supports displaying the Windows Thread
2566 Information Block (TIB) structure. This structure is visible either
2567 by using the new command `info w32 thread-information-block' or, by
2568 dereferencing the new convenience variable named `$_tlb', a
2569 thread-specific pointer to the TIB. This feature is also supported
2570 when remote debugging using GDBserver.
2572 * Static tracepoints
2574 Static tracepoints are calls in the user program into a tracing
2575 library. One such library is a port of the LTTng kernel tracer to
2576 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2577 When debugging with GDBserver, GDB now supports combining the GDB
2578 tracepoint machinery with such libraries. For example: the user can
2579 use GDB to probe a static tracepoint marker (a call from the user
2580 program into the tracing library) with the new "strace" command (see
2581 "New commands" below). This creates a "static tracepoint" in the
2582 breakpoint list, that can be manipulated with the same feature set
2583 as fast and regular tracepoints. E.g., collect registers, local and
2584 global variables, collect trace state variables, and define
2585 tracepoint conditions. In addition, the user can collect extra
2586 static tracepoint marker specific data, by collecting the new
2587 $_sdata internal variable. When analyzing the trace buffer, you can
2588 inspect $_sdata like any other variable available to GDB. For more
2589 information, see the "Tracepoints" chapter in GDB user manual. New
2590 remote packets have been defined to support static tracepoints, see
2591 the "New remote packets" section below.
2593 * Better reconstruction of tracepoints after disconnected tracing
2595 GDB will attempt to download the original source form of tracepoint
2596 definitions when starting a trace run, and then will upload these
2597 upon reconnection to the target, resulting in a more accurate
2598 reconstruction of the tracepoints that are in use on the target.
2602 You can now exercise direct control over the ways that GDB can
2603 affect your program. For instance, you can disallow the setting of
2604 breakpoints, so that the program can run continuously (assuming
2605 non-stop mode). In addition, the "observer" variable is available
2606 to switch all of the different controls; in observer mode, GDB
2607 cannot affect the target's behavior at all, which is useful for
2608 tasks like diagnosing live systems in the field.
2610 * The new convenience variable $_thread holds the number of the
2613 * New remote packets
2617 Return the address of the Windows Thread Information Block of a given thread.
2621 In response to several of the tracepoint packets, the target may now
2622 also respond with a number of intermediate `qRelocInsn' request
2623 packets before the final result packet, to have GDB handle
2624 relocating an instruction to execute at a different address. This
2625 is particularly useful for stubs that support fast tracepoints. GDB
2626 reports support for this feature in the qSupported packet.
2630 List static tracepoint markers in the target program.
2634 List static tracepoint markers at a given address in the target
2637 qXfer:statictrace:read
2639 Read the static trace data collected (by a `collect $_sdata'
2640 tracepoint action). The remote stub reports support for this packet
2641 to gdb's qSupported query.
2645 Send the current settings of GDB's permission flags.
2649 Send part of the source (textual) form of a tracepoint definition,
2650 which includes location, conditional, and action list.
2652 * The source command now accepts a -s option to force searching for the
2653 script in the source search path even if the script name specifies
2656 * New features in the GDB remote stub, GDBserver
2658 - GDBserver now support tracepoints (including fast tracepoints, and
2659 static tracepoints). The feature is currently supported by the
2660 i386-linux and amd64-linux builds. See the "Tracepoints support
2661 in gdbserver" section in the manual for more information.
2663 GDBserver JIT compiles the tracepoint's conditional agent
2664 expression bytecode into native code whenever possible for low
2665 overhead dynamic tracepoints conditionals. For such tracepoints,
2666 an expression that examines program state is evaluated when the
2667 tracepoint is reached, in order to determine whether to capture
2668 trace data. If the condition is simple and false, processing the
2669 tracepoint finishes very quickly and no data is gathered.
2671 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2672 for static tracepoints support.
2674 - GDBserver now supports x86_64 Windows 64-bit debugging.
2676 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2677 it understands register description.
2679 * The --batch flag now disables pagination and queries.
2681 * X86 general purpose registers
2683 GDB now supports reading/writing byte, word and double-word x86
2684 general purpose registers directly. This means you can use, say,
2685 $ah or $ax to refer, respectively, to the byte register AH and
2686 16-bit word register AX that are actually portions of the 32-bit
2687 register EAX or 64-bit register RAX.
2689 * The `commands' command now accepts a range of breakpoints to modify.
2690 A plain `commands' following a command that creates multiple
2691 breakpoints affects all the breakpoints set by that command. This
2692 applies to breakpoints set by `rbreak', and also applies when a
2693 single `break' command creates multiple breakpoints (e.g.,
2694 breakpoints on overloaded c++ functions).
2696 * The `rbreak' command now accepts a filename specification as part of
2697 its argument, limiting the functions selected by the regex to those
2698 in the specified file.
2700 * Support for remote debugging Windows and SymbianOS shared libraries
2701 from Unix hosts has been improved. Non Windows GDB builds now can
2702 understand target reported file names that follow MS-DOS based file
2703 system semantics, such as file names that include drive letters and
2704 use the backslash character as directory separator. This makes it
2705 possible to transparently use the "set sysroot" and "set
2706 solib-search-path" on Unix hosts to point as host copies of the
2707 target's shared libraries. See the new command "set
2708 target-file-system-kind" described below, and the "Commands to
2709 specify files" section in the user manual for more information.
2713 eval template, expressions...
2714 Convert the values of one or more expressions under the control
2715 of the string template to a command line, and call it.
2717 set target-file-system-kind unix|dos-based|auto
2718 show target-file-system-kind
2719 Set or show the assumed file system kind for target reported file
2722 save breakpoints <filename>
2723 Save all current breakpoint definitions to a file suitable for use
2724 in a later debugging session. To read the saved breakpoint
2725 definitions, use the `source' command.
2727 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2730 info static-tracepoint-markers
2731 Display information about static tracepoint markers in the target.
2733 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2734 Define a static tracepoint by probing a marker at the given
2735 function, line, address, or marker ID.
2739 Enable and disable observer mode.
2741 set may-write-registers on|off
2742 set may-write-memory on|off
2743 set may-insert-breakpoints on|off
2744 set may-insert-tracepoints on|off
2745 set may-insert-fast-tracepoints on|off
2746 set may-interrupt on|off
2747 Set individual permissions for GDB effects on the target. Note that
2748 some of these settings can have undesirable or surprising
2749 consequences, particularly when changed in the middle of a session.
2750 For instance, disabling the writing of memory can prevent
2751 breakpoints from being inserted, cause single-stepping to fail, or
2752 even crash your program, if you disable after breakpoints have been
2753 inserted. However, GDB should not crash.
2755 set record memory-query on|off
2756 show record memory-query
2757 Control whether to stop the inferior if memory changes caused
2758 by an instruction cannot be recorded.
2763 The disassemble command now supports "start,+length" form of two arguments.
2767 ** GDB now provides a new directory location, called the python directory,
2768 where Python scripts written for GDB can be installed. The location
2769 of that directory is <data-directory>/python, where <data-directory>
2770 is the GDB data directory. For more details, see section `Scripting
2771 GDB using Python' in the manual.
2773 ** The GDB Python API now has access to breakpoints, symbols, symbol
2774 tables, program spaces, inferiors, threads and frame's code blocks.
2775 Additionally, GDB Parameters can now be created from the API, and
2776 manipulated via set/show in the CLI.
2778 ** New functions gdb.target_charset, gdb.target_wide_charset,
2779 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2781 ** New exception gdb.GdbError.
2783 ** Pretty-printers are now also looked up in the current program space.
2785 ** Pretty-printers can now be individually enabled and disabled.
2787 ** GDB now looks for names of Python scripts to auto-load in a
2788 special section named `.debug_gdb_scripts', in addition to looking
2789 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2791 * Tracepoint actions were unified with breakpoint commands. In particular,
2792 there are no longer differences in "info break" output for breakpoints and
2793 tracepoints and the "commands" command can be used for both tracepoints and
2794 regular breakpoints.
2798 ARM Symbian arm*-*-symbianelf*
2800 * D language support.
2801 GDB now supports debugging programs written in the D programming
2804 * GDB now supports the extended ptrace interface for PowerPC which is
2805 available since Linux kernel version 2.6.34. This automatically enables
2806 any hardware breakpoints and additional hardware watchpoints available in
2807 the processor. The old ptrace interface exposes just one hardware
2808 watchpoint and no hardware breakpoints.
2810 * GDB is now able to use the Data Value Compare (DVC) register available on
2811 embedded PowerPC processors to implement in hardware simple watchpoint
2812 conditions of the form:
2814 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2816 This works in native GDB running on Linux kernels with the extended ptrace
2817 interface mentioned above.
2819 *** Changes in GDB 7.1
2823 ** Namespace Support
2825 GDB now supports importing of namespaces in C++. This enables the
2826 user to inspect variables from imported namespaces. Support for
2827 namepace aliasing has also been added. So, if a namespace is
2828 aliased in the current scope (e.g. namepace C=A; ) the user can
2829 print variables using the alias (e.g. (gdb) print C::x).
2833 All known bugs relating to the printing of virtual base class were
2834 fixed. It is now possible to call overloaded static methods using a
2839 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2840 and reinterpret_cast<> are now handled by the C++ expression parser.
2844 Xilinx MicroBlaze microblaze-*-*
2849 Xilinx MicroBlaze microblaze
2852 * Multi-program debugging.
2854 GDB now has support for multi-program (a.k.a. multi-executable or
2855 multi-exec) debugging. This allows for debugging multiple inferiors
2856 simultaneously each running a different program under the same GDB
2857 session. See "Debugging Multiple Inferiors and Programs" in the
2858 manual for more information. This implied some user visible changes
2859 in the multi-inferior support. For example, "info inferiors" now
2860 lists inferiors that are not running yet or that have exited
2861 already. See also "New commands" and "New options" below.
2863 * New tracing features
2865 GDB's tracepoint facility now includes several new features:
2867 ** Trace state variables
2869 GDB tracepoints now include support for trace state variables, which
2870 are variables managed by the target agent during a tracing
2871 experiment. They are useful for tracepoints that trigger each
2872 other, so for instance one tracepoint can count hits in a variable,
2873 and then a second tracepoint has a condition that is true when the
2874 count reaches a particular value. Trace state variables share the
2875 $-syntax of GDB convenience variables, and can appear in both
2876 tracepoint actions and condition expressions. Use the "tvariable"
2877 command to create, and "info tvariables" to view; see "Trace State
2878 Variables" in the manual for more detail.
2882 GDB now includes an option for defining fast tracepoints, which
2883 targets may implement more efficiently, such as by installing a jump
2884 into the target agent rather than a trap instruction. The resulting
2885 speedup can be by two orders of magnitude or more, although the
2886 tradeoff is that some program locations on some target architectures
2887 might not allow fast tracepoint installation, for instance if the
2888 instruction to be replaced is shorter than the jump. To request a
2889 fast tracepoint, use the "ftrace" command, with syntax identical to
2890 the regular trace command.
2892 ** Disconnected tracing
2894 It is now possible to detach GDB from the target while it is running
2895 a trace experiment, then reconnect later to see how the experiment
2896 is going. In addition, a new variable disconnected-tracing lets you
2897 tell the target agent whether to continue running a trace if the
2898 connection is lost unexpectedly.
2902 GDB now has the ability to save the trace buffer into a file, and
2903 then use that file as a target, similarly to you can do with
2904 corefiles. You can select trace frames, print data that was
2905 collected in them, and use tstatus to display the state of the
2906 tracing run at the moment that it was saved. To create a trace
2907 file, use "tsave <filename>", and to use it, do "target tfile
2910 ** Circular trace buffer
2912 You can ask the target agent to handle the trace buffer as a
2913 circular buffer, discarding the oldest trace frames to make room for
2914 newer ones, by setting circular-trace-buffer to on. This feature may
2915 not be available for all target agents.
2920 The disassemble command, when invoked with two arguments, now requires
2921 the arguments to be comma-separated.
2924 The info variables command now displays variable definitions. Files
2925 which only declare a variable are not shown.
2928 The source command is now capable of sourcing Python scripts.
2929 This feature is dependent on the debugger being build with Python
2932 Related to this enhancement is also the introduction of a new command
2933 "set script-extension" (see below).
2935 * New commands (for set/show, see "New options" below)
2937 record save [<FILENAME>]
2938 Save a file (in core file format) containing the process record
2939 execution log for replay debugging at a later time.
2941 record restore <FILENAME>
2942 Restore the process record execution log that was saved at an
2943 earlier time, for replay debugging.
2945 add-inferior [-copies <N>] [-exec <FILENAME>]
2948 clone-inferior [-copies <N>] [ID]
2949 Make a new inferior ready to execute the same program another
2950 inferior has loaded.
2955 maint info program-spaces
2956 List the program spaces loaded into GDB.
2958 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2959 show remote interrupt-sequence
2960 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2961 as the sequence to the remote target in order to interrupt the execution.
2962 Ctrl-C is a default. Some system prefers BREAK which is high level of
2963 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2964 Magic SysRq g. It is BREAK signal and character 'g'.
2966 set remote interrupt-on-connect [on | off]
2967 show remote interrupt-on-connect
2968 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2969 remote target when gdb connects to it. This is needed when you debug
2972 set remotebreak [on | off]
2974 Deprecated. Use "set/show remote interrupt-sequence" instead.
2976 tvariable $NAME [ = EXP ]
2977 Create or modify a trace state variable.
2980 List trace state variables and their values.
2982 delete tvariable $NAME ...
2983 Delete one or more trace state variables.
2986 Evaluate the given expressions without collecting anything into the
2987 trace buffer. (Valid in tracepoint actions only.)
2989 ftrace FN / FILE:LINE / *ADDR
2990 Define a fast tracepoint at the given function, line, or address.
2992 * New expression syntax
2994 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2995 GDB now parses 0b101010 identically with 42.
2999 set follow-exec-mode new|same
3000 show follow-exec-mode
3001 Control whether GDB reuses the same inferior across an exec call or
3002 creates a new one. This is useful to be able to restart the old
3003 executable after the inferior having done an exec call.
3005 set default-collect EXPR, ...
3006 show default-collect
3007 Define a list of expressions to be collected at each tracepoint.
3008 This is a useful way to ensure essential items are not overlooked,
3009 such as registers or a critical global variable.
3011 set disconnected-tracing
3012 show disconnected-tracing
3013 If set to 1, the target is instructed to continue tracing if it
3014 loses its connection to GDB. If 0, the target is to stop tracing
3017 set circular-trace-buffer
3018 show circular-trace-buffer
3019 If set to on, the target is instructed to use a circular trace buffer
3020 and discard the oldest trace frames instead of stopping the trace due
3021 to a full trace buffer. If set to off, the trace stops when the buffer
3022 fills up. Some targets may not support this.
3024 set script-extension off|soft|strict
3025 show script-extension
3026 If set to "off", the debugger does not perform any script language
3027 recognition, and all sourced files are assumed to be GDB scripts.
3028 If set to "soft" (the default), files are sourced according to
3029 filename extension, falling back to GDB scripts if the first
3031 If set to "strict", files are sourced according to filename extension.
3033 set ada trust-PAD-over-XVS on|off
3034 show ada trust-PAD-over-XVS
3035 If off, activate a workaround against a bug in the debugging information
3036 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3037 the GCC sources for more information about the GNAT encoding and
3038 PAD types in particular). It is always safe to set this option to
3039 off, but this introduces a slight performance penalty. The default
3042 * Python API Improvements
3044 ** GDB provides the new class gdb.LazyString. This is useful in
3045 some pretty-printing cases. The new method gdb.Value.lazy_string
3046 provides a simple way to create objects of this type.
3048 ** The fields returned by gdb.Type.fields now have an
3049 `is_base_class' attribute.
3051 ** The new method gdb.Type.range returns the range of an array type.
3053 ** The new method gdb.parse_and_eval can be used to parse and
3054 evaluate an expression.
3056 * New remote packets
3059 Define a trace state variable.
3062 Get the current value of a trace state variable.
3065 Set desired tracing behavior upon disconnection.
3068 Set the trace buffer to be linear or circular.
3071 Get data about the tracepoints currently in use.
3075 Process record now works correctly with hardware watchpoints.
3077 Multiple bug fixes have been made to the mips-irix port, making it
3078 much more reliable. In particular:
3079 - Debugging threaded applications is now possible again. Previously,
3080 GDB would hang while starting the program, or while waiting for
3081 the program to stop at a breakpoint.
3082 - Attaching to a running process no longer hangs.
3083 - An error occurring while loading a core file has been fixed.
3084 - Changing the value of the PC register now works again. This fixes
3085 problems observed when using the "jump" command, or when calling
3086 a function from GDB, or even when assigning a new value to $pc.
3087 - With the "finish" and "return" commands, the return value for functions
3088 returning a small array is now correctly printed.
3089 - It is now possible to break on shared library code which gets executed
3090 during a shared library init phase (code executed while executing
3091 their .init section). Previously, the breakpoint would have no effect.
3092 - GDB is now able to backtrace through the signal handler for
3093 non-threaded programs.
3095 PIE (Position Independent Executable) programs debugging is now supported.
3096 This includes debugging execution of PIC (Position Independent Code) shared
3097 libraries although for that, it should be possible to run such libraries as an
3100 *** Changes in GDB 7.0
3102 * GDB now has an interface for JIT compilation. Applications that
3103 dynamically generate code can create symbol files in memory and register
3104 them with GDB. For users, the feature should work transparently, and
3105 for JIT developers, the interface is documented in the GDB manual in the
3106 "JIT Compilation Interface" chapter.
3108 * Tracepoints may now be conditional. The syntax is as for
3109 breakpoints; either an "if" clause appended to the "trace" command,
3110 or the "condition" command is available. GDB sends the condition to
3111 the target for evaluation using the same bytecode format as is used
3112 for tracepoint actions.
3114 * The disassemble command now supports: an optional /r modifier, print the
3115 raw instructions in hex as well as in symbolic form, and an optional /m
3116 modifier to print mixed source+assembly.
3118 * Process record and replay
3120 In a architecture environment that supports ``process record and
3121 replay'', ``process record and replay'' target can record a log of
3122 the process execution, and replay it with both forward and reverse
3125 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3126 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3127 set execution-direction {forward|reverse}, for targets that support
3130 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3131 feature is available with a native GDB running on kernel version
3134 * GDB now has support for multi-byte and wide character sets on the
3135 target. Strings whose character type is wchar_t, char16_t, or
3136 char32_t are now correctly printed. GDB supports wide- and unicode-
3137 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3138 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3139 `printf'. This feature requires iconv to work properly; if your
3140 system does not have a working iconv, GDB can use GNU libiconv. See
3141 the installation instructions for more information.
3143 * GDB now supports automatic retrieval of shared library files from
3144 remote targets. To use this feature, specify a system root that begins
3145 with the `remote:' prefix, either via the `set sysroot' command or via
3146 the `--with-sysroot' configure-time option.
3148 * "info sharedlibrary" now takes an optional regex of libraries to show,
3149 and it now reports if a shared library has no debugging information.
3151 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3152 now complete on file names.
3154 * When completing in expressions, gdb will attempt to limit
3155 completions to allowable structure or union fields, where appropriate.
3156 For instance, consider:
3158 # struct example { int f1; double f2; };
3159 # struct example variable;
3162 If the user types TAB at the end of this command line, the available
3163 completions will be "f1" and "f2".
3165 * Inlined functions are now supported. They show up in backtraces, and
3166 the "step", "next", and "finish" commands handle them automatically.
3168 * GDB now supports the token-splicing (##) and stringification (#)
3169 operators when expanding macros. It also supports variable-arity
3172 * GDB now supports inspecting extra signal information, exported by
3173 the new $_siginfo convenience variable. The feature is currently
3174 implemented on linux ARM, i386 and amd64.
3176 * GDB can now display the VFP floating point registers and NEON vector
3177 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3178 can provide these registers (requires Linux 2.6.30 or later). Remote
3179 and simulator targets may also provide them.
3181 * New remote packets
3184 Search memory for a sequence of bytes.
3187 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3188 operation over reliable transport links. Use of this packet is
3189 controlled by the `set remote noack-packet' command.
3192 Kill the process with the specified process ID. Use this in preference
3193 to `k' when multiprocess protocol extensions are supported.
3196 Obtains additional operating system information
3200 Read or write additional signal information.
3202 * Removed remote protocol undocumented extension
3204 An undocumented extension to the remote protocol's `S' stop reply
3205 packet that permited the stub to pass a process id was removed.
3206 Remote servers should use the `T' stop reply packet instead.
3208 * GDB now supports multiple function calling conventions according to the
3209 DWARF-2 DW_AT_calling_convention function attribute.
3211 * The SH target utilizes the aforementioned change to distinguish between gcc
3212 and Renesas calling convention. It also adds the new CLI commands
3213 `set/show sh calling-convention'.
3215 * GDB can now read compressed debug sections, as produced by GNU gold
3216 with the --compress-debug-sections=zlib flag.
3218 * 64-bit core files are now supported on AIX.
3220 * Thread switching is now supported on Tru64.
3222 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3223 which will be allocated using malloc later in program execution.
3225 * The qXfer:libraries:read remote procotol packet now allows passing a
3226 list of section offsets.
3228 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3229 conditions handling signals delivered during attach or thread creation
3230 have also been fixed.
3232 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3233 From the user's standpoint, all unqualified instances of True and False
3234 are treated as the standard definitions, regardless of context.
3236 * GDB now parses C++ symbol and type names more flexibly. For
3239 template<typename T> class C { };
3242 GDB will now correctly handle all of:
3244 ptype C<char const *>
3245 ptype C<char const*>
3246 ptype C<const char *>
3247 ptype C<const char*>
3249 * New features in the GDB remote stub, gdbserver
3251 - The "--wrapper" command-line argument tells gdbserver to use a
3252 wrapper program to launch programs for debugging.
3254 - On PowerPC and S/390 targets, it is now possible to use a single
3255 gdbserver executable to debug both 32-bit and 64-bit programs.
3256 (This requires gdbserver itself to be built as a 64-bit executable.)
3258 - gdbserver uses the new noack protocol mode for TCP connections to
3259 reduce communications latency, if also supported and enabled in GDB.
3261 - Support for the sparc64-linux-gnu target is now included in
3264 - The amd64-linux build of gdbserver now supports debugging both
3265 32-bit and 64-bit programs.
3267 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3268 now support hardware watchpoints, and will use them automatically
3273 GDB now has support for scripting using Python. Whether this is
3274 available is determined at configure time.
3276 New GDB commands can now be written in Python.
3278 * Ada tasking support
3280 Ada tasks can now be inspected in GDB. The following commands have
3284 Print the list of Ada tasks.
3286 Print detailed information about task number N.
3288 Print the task number of the current task.
3290 Switch the context of debugging to task number N.
3292 * Support for user-defined prefixed commands. The "define" command can
3293 add new commands to existing prefixes, e.g. "target".
3295 * Multi-inferior, multi-process debugging.
3297 GDB now has generalized support for multi-inferior debugging. See
3298 "Debugging Multiple Inferiors" in the manual for more information.
3299 Although availability still depends on target support, the command
3300 set is more uniform now. The GNU/Linux specific multi-forks support
3301 has been migrated to this new framework. This implied some user
3302 visible changes; see "New commands" and also "Removed commands"
3305 * Target descriptions can now describe the target OS ABI. See the
3306 "Target Description Format" section in the user manual for more
3309 * Target descriptions can now describe "compatible" architectures
3310 to indicate that the target can execute applications for a different
3311 architecture in addition to those for the main target architecture.
3312 See the "Target Description Format" section in the user manual for
3315 * Multi-architecture debugging.
3317 GDB now includes general supports for debugging applications on
3318 hybrid systems that use more than one single processor architecture
3319 at the same time. Each such hybrid architecture still requires
3320 specific support to be added. The only hybrid architecture supported
3321 in this version of GDB is the Cell Broadband Engine.
3323 * GDB now supports integrated debugging of Cell/B.E. applications that
3324 use both the PPU and SPU architectures. To enable support for hybrid
3325 Cell/B.E. debugging, you need to configure GDB to support both the
3326 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3327 --enable-targets configure option.
3329 * Non-stop mode debugging.
3331 For some targets, GDB now supports an optional mode of operation in
3332 which you can examine stopped threads while other threads continue
3333 to execute freely. This is referred to as non-stop mode, with the
3334 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3335 section in the user manual for more information.
3337 To be able to support remote non-stop debugging, a remote stub needs
3338 to implement the non-stop mode remote protocol extensions, as
3339 described in the "Remote Non-Stop" section of the user manual. The
3340 GDB remote stub, gdbserver, has been adjusted to support these
3341 extensions on linux targets.
3343 * New commands (for set/show, see "New options" below)
3345 catch syscall [NAME(S) | NUMBER(S)]
3346 Catch system calls. Arguments, which should be names of system
3347 calls or their numbers, mean catch only those syscalls. Without
3348 arguments, every syscall will be caught. When the inferior issues
3349 any of the specified syscalls, GDB will stop and announce the system
3350 call, both when it is called and when its call returns. This
3351 feature is currently available with a native GDB running on the
3352 Linux Kernel, under the following architectures: x86, x86_64,
3353 PowerPC and PowerPC64.
3355 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3357 Search memory for a sequence of bytes.
3359 maint set python print-stack
3360 maint show python print-stack
3361 Show a stack trace when an error is encountered in a Python script.
3364 Invoke CODE by passing it to the Python interpreter.
3369 These allow macros to be defined, undefined, and listed
3373 Show operating system information about processes.
3376 List the inferiors currently under GDB's control.
3379 Switch focus to inferior number NUM.
3382 Detach from inferior number NUM.
3385 Kill inferior number NUM.
3389 set spu stop-on-load
3390 show spu stop-on-load
3391 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3393 set spu auto-flush-cache
3394 show spu auto-flush-cache
3395 Control whether to automatically flush the software-managed cache
3396 during Cell/B.E. debugging.
3398 set sh calling-convention
3399 show sh calling-convention
3400 Control the calling convention used when calling SH target functions.
3403 show debug timestamp
3404 Control display of timestamps with GDB debugging output.
3406 set disassemble-next-line
3407 show disassemble-next-line
3408 Control display of disassembled source lines or instructions when
3411 set remote noack-packet
3412 show remote noack-packet
3413 Set/show the use of remote protocol QStartNoAckMode packet. See above
3414 under "New remote packets."
3416 set remote query-attached-packet
3417 show remote query-attached-packet
3418 Control use of remote protocol `qAttached' (query-attached) packet.
3420 set remote read-siginfo-object
3421 show remote read-siginfo-object
3422 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3425 set remote write-siginfo-object
3426 show remote write-siginfo-object
3427 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3430 set remote reverse-continue
3431 show remote reverse-continue
3432 Control use of remote protocol 'bc' (reverse-continue) packet.
3434 set remote reverse-step
3435 show remote reverse-step
3436 Control use of remote protocol 'bs' (reverse-step) packet.
3438 set displaced-stepping
3439 show displaced-stepping
3440 Control displaced stepping mode. Displaced stepping is a way to
3441 single-step over breakpoints without removing them from the debuggee.
3442 Also known as "out-of-line single-stepping".
3445 show debug displaced
3446 Control display of debugging info for displaced stepping.
3448 maint set internal-error
3449 maint show internal-error
3450 Control what GDB does when an internal error is detected.
3452 maint set internal-warning
3453 maint show internal-warning
3454 Control what GDB does when an internal warning is detected.
3459 Use a wrapper program to launch programs for debugging.
3461 set multiple-symbols (all|ask|cancel)
3462 show multiple-symbols
3463 The value of this variable can be changed to adjust the debugger behavior
3464 when an expression or a breakpoint location contains an ambiguous symbol
3465 name (an overloaded function name, for instance).
3467 set breakpoint always-inserted
3468 show breakpoint always-inserted
3469 Keep breakpoints always inserted in the target, as opposed to inserting
3470 them when resuming the target, and removing them when the target stops.
3471 This option can improve debugger performance on slow remote targets.
3473 set arm fallback-mode (arm|thumb|auto)
3474 show arm fallback-mode
3475 set arm force-mode (arm|thumb|auto)
3477 These commands control how ARM GDB determines whether instructions
3478 are ARM or Thumb. The default for both settings is auto, which uses
3479 the current CPSR value for instructions without symbols; previous
3480 versions of GDB behaved as if "set arm fallback-mode arm".
3482 set disable-randomization
3483 show disable-randomization
3484 Standalone programs run with the virtual address space randomization enabled
3485 by default on some platforms. This option keeps the addresses stable across
3486 multiple debugging sessions.
3490 Control whether other threads are stopped or not when some thread hits
3495 Requests that asynchronous execution is enabled in the target, if available.
3496 In this case, it's possible to resume target in the background, and interact
3497 with GDB while the target is running. "show target-async" displays the
3498 current state of asynchronous execution of the target.
3500 set target-wide-charset
3501 show target-wide-charset
3502 The target-wide-charset is the name of the character set that GDB
3503 uses when printing characters whose type is wchar_t.
3505 set tcp auto-retry (on|off)
3507 set tcp connect-timeout
3508 show tcp connect-timeout
3509 These commands allow GDB to retry failed TCP connections to a remote stub
3510 with a specified timeout period; this is useful if the stub is launched
3511 in parallel with GDB but may not be ready to accept connections immediately.
3513 set libthread-db-search-path
3514 show libthread-db-search-path
3515 Control list of directories which GDB will search for appropriate
3518 set schedule-multiple (on|off)
3519 show schedule-multiple
3520 Allow GDB to resume all threads of all processes or only threads of
3521 the current process.
3525 Use more aggressive caching for accesses to the stack. This improves
3526 performance of remote debugging (particularly backtraces) without
3527 affecting correctness.
3529 set interactive-mode (on|off|auto)
3530 show interactive-mode
3531 Control whether GDB runs in interactive mode (on) or not (off).
3532 When in interactive mode, GDB waits for the user to answer all
3533 queries. Otherwise, GDB does not wait and assumes the default
3534 answer. When set to auto (the default), GDB determines which
3535 mode to use based on the stdin settings.
3540 For program forks, this is replaced by the new more generic `info
3541 inferiors' command. To list checkpoints, you can still use the
3542 `info checkpoints' command, which was an alias for the `info forks'
3546 Replaced by the new `inferior' command. To switch between
3547 checkpoints, you can still use the `restart' command, which was an
3548 alias for the `fork' command.
3551 This is removed, since some targets don't have a notion of
3552 processes. To switch between processes, you can still use the
3553 `inferior' command using GDB's own inferior number.
3556 For program forks, this is replaced by the new more generic `kill
3557 inferior' command. To delete a checkpoint, you can still use the
3558 `delete checkpoint' command, which was an alias for the `delete
3562 For program forks, this is replaced by the new more generic `detach
3563 inferior' command. To detach a checkpoint, you can still use the
3564 `detach checkpoint' command, which was an alias for the `detach
3567 * New native configurations
3569 x86/x86_64 Darwin i[34567]86-*-darwin*
3571 x86_64 MinGW x86_64-*-mingw*
3575 Lattice Mico32 lm32-*
3576 x86 DICOS i[34567]86-*-dicos*
3577 x86_64 DICOS x86_64-*-dicos*
3580 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3581 (mingw32ce) debugging.
3587 These commands were actually not implemented on any target.
3589 *** Changes in GDB 6.8
3591 * New native configurations
3593 NetBSD/hppa hppa*-*netbsd*
3594 Xtensa GNU/Linux xtensa*-*-linux*
3598 NetBSD/hppa hppa*-*-netbsd*
3599 Xtensa GNU/Lunux xtensa*-*-linux*
3601 * Change in command line behavior -- corefiles vs. process ids.
3603 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3604 attaching to process NUMBER fails, GDB no longer attempts to open a
3605 core file named NUMBER. Attaching to a program using the -c option
3606 is no longer supported. Instead, use the '-p' or '--pid' options.
3608 * GDB can now be built as a native debugger for debugging Windows x86
3609 (mingw32) Portable Executable (PE) programs.
3611 * Pending breakpoints no longer change their number when their address
3614 * GDB now supports breakpoints with multiple locations,
3615 including breakpoints on C++ constructors, inside C++ templates,
3616 and in inlined functions.
3618 * GDB's ability to debug optimized code has been improved. GDB more
3619 accurately identifies function bodies and lexical blocks that occupy
3620 more than one contiguous range of addresses.
3622 * Target descriptions can now describe registers for PowerPC.
3624 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3625 registers on PowerPC targets.
3627 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3628 targets even when the libthread_db library is not available.
3630 * The GDB remote stub, gdbserver, now supports the new file transfer
3631 commands (remote put, remote get, and remote delete).
3633 * The GDB remote stub, gdbserver, now supports run and attach in
3634 extended-remote mode.
3636 * hppa*64*-*-hpux11* target broken
3637 The debugger is unable to start a program and fails with the following
3638 error: "Error trying to get information about dynamic linker".
3639 The gdb-6.7 release is also affected.
3641 * GDB now supports the --enable-targets= configure option to allow
3642 building a single GDB executable that supports multiple remote
3643 target architectures.
3645 * GDB now supports debugging C and C++ programs which use the
3646 Decimal Floating Point extension. In addition, the PowerPC target
3647 now has a set of pseudo-registers to inspect decimal float values
3648 stored in two consecutive float registers.
3650 * The -break-insert MI command can optionally create pending
3653 * Improved support for debugging Ada
3654 Many improvements to the Ada language support have been made. These
3656 - Better support for Ada2005 interface types
3657 - Improved handling of arrays and slices in general
3658 - Better support for Taft-amendment types
3659 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3661 - Improved command completion in Ada
3664 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3669 set print frame-arguments (all|scalars|none)
3670 show print frame-arguments
3671 The value of this variable can be changed to control which argument
3672 values should be printed by the debugger when displaying a frame.
3677 Transfer files to and from a remote target, and delete remote files.
3684 Transfer files to and from a remote target, and delete remote files.
3686 * New remote packets
3693 Open, close, read, write, and delete files on the remote system.
3696 Attach to an existing process on the remote system, in extended-remote
3700 Run a new process on the remote system, in extended-remote mode.
3702 *** Changes in GDB 6.7
3704 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3705 bfd, libiberty and opcodes, as revealed by static analysis donated by
3706 Coverity, Inc. (http://scan.coverity.com).
3708 * When looking up multiply-defined global symbols, GDB will now prefer the
3709 symbol definition in the current shared library if it was built using the
3710 -Bsymbolic linker option.
3712 * When the Text User Interface (TUI) is not configured, GDB will now
3713 recognize the -tui command-line option and print a message that the TUI
3716 * The GDB remote stub, gdbserver, now has lower overhead for high
3717 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3719 * GDB for MIPS targets now autodetects whether a remote target provides
3720 32-bit or 64-bit register values.
3722 * Support for C++ member pointers has been improved.
3724 * GDB now understands XML target descriptions, which specify the
3725 target's overall architecture. GDB can read a description from
3726 a local file or over the remote serial protocol.
3728 * Vectors of single-byte data use a new integer type which is not
3729 automatically displayed as character or string data.
3731 * The /s format now works with the print command. It displays
3732 arrays of single-byte integers and pointers to single-byte integers
3735 * Target descriptions can now describe target-specific registers,
3736 for architectures which have implemented the support (currently
3737 only ARM, M68K, and MIPS).
3739 * GDB and the GDB remote stub, gdbserver, now support the XScale
3742 * The GDB remote stub, gdbserver, has been updated to support
3743 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3744 has been rewritten to use the standard GDB remote protocol.
3746 * GDB can now step into C++ functions which are called through thunks.
3748 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3750 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3751 layout. It also supports a TextSeg= and DataSeg= response when only
3752 segment base addresses (rather than offsets) are available.
3754 * The /i format now outputs any trailing branch delay slot instructions
3755 immediately following the last instruction within the count specified.
3757 * The GDB remote protocol "T" stop reply packet now supports a
3758 "library" response. Combined with the new "qXfer:libraries:read"
3759 packet, this response allows GDB to debug shared libraries on targets
3760 where the operating system manages the list of loaded libraries (e.g.
3761 Windows and SymbianOS).
3763 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3764 (DLLs) on Windows and Windows CE targets.
3766 * GDB now supports a faster verification that a .debug file matches its binary
3767 according to its build-id signature, if the signature is present.
3773 Enable or disable hardware flow control (RTS/CTS) on the serial port
3774 when debugging using remote targets.
3776 set mem inaccessible-by-default
3777 show mem inaccessible-by-default
3778 If the target supplies a memory map, for instance via the remote
3779 protocol's "qXfer:memory-map:read" packet, setting this variable
3780 prevents GDB from accessing memory outside the memory map. This
3781 is useful for targets with memory mapped registers or which react
3782 badly to accesses of unmapped address space.
3784 set breakpoint auto-hw
3785 show breakpoint auto-hw
3786 If the target supplies a memory map, for instance via the remote
3787 protocol's "qXfer:memory-map:read" packet, setting this variable
3788 lets GDB use hardware breakpoints automatically for memory regions
3789 where it can not use software breakpoints. This covers both the
3790 "break" command and internal breakpoints used for other commands
3791 including "next" and "finish".
3794 catch exception unhandled
3795 Stop the program execution when Ada exceptions are raised.
3798 Stop the program execution when an Ada assertion failed.
3802 Set an alternate system root for target files. This is a more
3803 general version of "set solib-absolute-prefix", which is now
3804 an alias to "set sysroot".
3807 Provide extended SPU facility status information. This set of
3808 commands is available only when debugging the Cell/B.E. SPU
3811 * New native configurations
3813 OpenBSD/sh sh*-*openbsd*
3816 unset tdesc filename
3818 Use the specified local file as an XML target description, and do
3819 not query the target for its built-in description.
3823 OpenBSD/sh sh*-*-openbsd*
3824 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3825 Toshiba Media Processor mep-elf
3827 * New remote packets
3830 Ignore the specified signals; pass them directly to the debugged program
3831 without stopping other threads or reporting them to GDB.
3833 qXfer:features:read:
3834 Read an XML target description from the target, which describes its
3839 Read or write contents of an spufs file on the target system. These
3840 packets are available only on the Cell/B.E. SPU architecture.
3842 qXfer:libraries:read:
3843 Report the loaded shared libraries. Combined with new "T" packet
3844 response, this packet allows GDB to debug shared libraries on
3845 targets where the operating system manages the list of loaded
3846 libraries (e.g. Windows and SymbianOS).
3850 Support for these obsolete configurations has been removed.
3858 i[34567]86-*-lynxos*
3859 i[34567]86-*-netware*
3860 i[34567]86-*-sco3.2v5*
3861 i[34567]86-*-sco3.2v4*
3863 i[34567]86-*-sysv4.2*
3866 i[34567]86-*-unixware2*
3867 i[34567]86-*-unixware*
3876 * Other removed features
3883 Various m68k-only ROM monitors.
3890 Various Renesas ROM monitors and debugging interfaces for SH and
3895 Support for a Macraigor serial interface to on-chip debugging.
3896 GDB does not directly support the newer parallel or USB
3901 A debug information format. The predecessor to DWARF 2 and
3902 DWARF 3, which are still supported.
3904 Support for the HP aCC compiler on HP-UX/PA-RISC
3906 SOM-encapsulated symbolic debugging information, automatic
3907 invocation of pxdb, and the aCC custom C++ ABI. This does not
3908 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3909 with aCC can still be debugged on an assembly level.
3911 MIPS ".pdr" sections
3913 A MIPS-specific format used to describe stack frame layout
3914 in debugging information.
3918 GDB could work with an older version of Guile to debug
3919 the interpreter and Scheme programs running in it.
3921 set mips stack-arg-size
3922 set mips saved-gpreg-size
3924 Use "set mips abi" to control parameter passing for MIPS.
3926 *** Changes in GDB 6.6
3931 Cell Broadband Engine SPU spu-elf
3933 * GDB can now be configured as a cross-debugger targeting native Windows
3934 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3935 running on a Windows system over TCP/IP to debug Windows programs.
3937 * The GDB remote stub, gdbserver, has been updated to support Windows and
3938 Cygwin debugging. Both single-threaded and multi-threaded programs are
3941 * The "set trust-readonly-sections" command works again. This command was
3942 broken in GDB 6.3, 6.4, and 6.5.
3944 * The "load" command now supports writing to flash memory, if the remote
3945 stub provides the required support.
3947 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3948 longer requires symbolic debug information (e.g. DWARF-2).
3953 unset substitute-path
3954 show substitute-path
3955 Manage a list of substitution rules that GDB uses to rewrite the name
3956 of the directories where the sources are located. This can be useful
3957 for instance when the sources were moved to a different location
3958 between compilation and debugging.
3962 Print each CLI command as it is executed. Each command is prefixed with
3963 a number of `+' symbols representing the nesting depth.
3964 The source command now has a `-v' option to enable the same feature.
3968 The ARM Demon monitor support (RDP protocol, "target rdp").
3970 Kernel Object Display, an embedded debugging feature which only worked with
3971 an obsolete version of Cisco IOS.
3973 The 'set download-write-size' and 'show download-write-size' commands.
3975 * New remote packets
3978 Tell a stub about GDB client features, and request remote target features.
3979 The first feature implemented is PacketSize, which allows the target to
3980 specify the size of packets it can handle - to minimize the number of
3981 packets required and improve performance when connected to a remote
3985 Fetch an OS auxilliary vector from the remote stub. This packet is a
3986 more efficient replacement for qPart:auxv:read.
3988 qXfer:memory-map:read:
3989 Fetch a memory map from the remote stub, including information about
3990 RAM, ROM, and flash memory devices.
3995 Erase and program a flash memory device.
3997 * Removed remote packets
4000 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4001 used it, and only gdbserver implemented it.
4003 *** Changes in GDB 6.5
4007 Renesas M32C/M16C m32c-elf
4009 Morpho Technologies ms1 ms1-elf
4013 init-if-undefined Initialize a convenience variable, but
4014 only if it doesn't already have a value.
4016 The following commands are presently only implemented for native GNU/Linux:
4018 checkpoint Save a snapshot of the program state.
4020 restart <n> Return the program state to a
4021 previously saved state.
4023 info checkpoints List currently saved checkpoints.
4025 delete-checkpoint <n> Delete a previously saved checkpoint.
4027 set|show detach-on-fork Tell gdb whether to detach from a newly
4028 forked process, or to keep debugging it.
4030 info forks List forks of the user program that
4031 are available to be debugged.
4033 fork <n> Switch to debugging one of several
4034 forks of the user program that are
4035 available to be debugged.
4037 delete-fork <n> Delete a fork from the list of forks
4038 that are available to be debugged (and
4039 kill the forked process).
4041 detach-fork <n> Delete a fork from the list of forks
4042 that are available to be debugged (and
4043 allow the process to continue).
4047 Morpho Technologies ms2 ms1-elf
4049 * Improved Windows host support
4051 GDB now builds as a cross debugger hosted on i686-mingw32, including
4052 native console support, and remote communications using either
4053 network sockets or serial ports.
4055 * Improved Modula-2 language support
4057 GDB can now print most types in the Modula-2 syntax. This includes:
4058 basic types, set types, record types, enumerated types, range types,
4059 pointer types and ARRAY types. Procedure var parameters are correctly
4060 printed and hexadecimal addresses and character constants are also
4061 written in the Modula-2 syntax. Best results can be obtained by using
4062 GNU Modula-2 together with the -gdwarf-2 command line option.
4066 The ARM rdi-share module.
4068 The Netware NLM debug server.
4070 *** Changes in GDB 6.4
4072 * New native configurations
4074 OpenBSD/arm arm*-*-openbsd*
4075 OpenBSD/mips64 mips64-*-openbsd*
4079 Morpho Technologies ms1 ms1-elf
4081 * New command line options
4083 --batch-silent As for --batch, but totally silent.
4084 --return-child-result The debugger will exist with the same value
4085 the child (debugged) program exited with.
4086 --eval-command COMMAND, -ex COMMAND
4087 Execute a single GDB CLI command. This may be
4088 specified multiple times and in conjunction
4089 with the --command (-x) option.
4091 * Deprecated commands removed
4093 The following commands, that were deprecated in 2000, have been
4097 set|show arm disassembly-flavor set|show arm disassembler
4098 othernames set arm disassembler
4099 set|show remotedebug set|show debug remote
4100 set|show archdebug set|show debug arch
4101 set|show eventdebug set|show debug event
4104 * New BSD user-level threads support
4106 It is now possible to debug programs using the user-level threads
4107 library on OpenBSD and FreeBSD. Currently supported (target)
4110 FreeBSD/amd64 x86_64-*-freebsd*
4111 FreeBSD/i386 i386-*-freebsd*
4112 OpenBSD/i386 i386-*-openbsd*
4114 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4115 are not yet supported.
4117 * New support for Matsushita MN10300 w/sim added
4118 (Work in progress). mn10300-elf.
4120 * REMOVED configurations and files
4122 VxWorks and the XDR protocol *-*-vxworks
4123 Motorola MCORE mcore-*-*
4124 National Semiconductor NS32000 ns32k-*-*
4126 * New "set print array-indexes" command
4128 After turning this setting "on", GDB prints the index of each element
4129 when displaying arrays. The default is "off" to preserve the previous
4132 * VAX floating point support
4134 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4136 * User-defined command support
4138 In addition to using $arg0..$arg9 for argument passing, it is now possible
4139 to use $argc to determine now many arguments have been passed. See the
4140 section on user-defined commands in the user manual for more information.
4142 *** Changes in GDB 6.3:
4144 * New command line option
4146 GDB now accepts -l followed by a number to set the timeout for remote
4149 * GDB works with GCC -feliminate-dwarf2-dups
4151 GDB now supports a more compact representation of DWARF-2 debug
4152 information using DW_FORM_ref_addr references. These are produced
4153 by GCC with the option -feliminate-dwarf2-dups and also by some
4154 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4155 to use -feliminate-dwarf2-dups.
4157 * Internationalization
4159 When supported by the host system, GDB will be built with
4160 internationalization (libintl). The task of marking up the sources is
4161 continued, we're looking forward to our first translation.
4165 Initial support for debugging programs compiled with the GNAT
4166 implementation of the Ada programming language has been integrated
4167 into GDB. In this release, support is limited to expression evaluation.
4169 * New native configurations
4171 GNU/Linux/m32r m32r-*-linux-gnu
4175 GDB's remote protocol now includes support for the 'p' packet. This
4176 packet is used to fetch individual registers from a remote inferior.
4178 * END-OF-LIFE registers[] compatibility module
4180 GDB's internal register infrastructure has been completely rewritten.
4181 The new infrastructure making possible the implementation of key new
4182 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4185 GDB 6.3 will be the last release to include the the registers[]
4186 compatibility module that allowed out-of-date configurations to
4187 continue to work. This change directly impacts the following
4197 powerpc bdm protocol
4199 Unless there is activity to revive these configurations, they will be
4200 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4202 * OBSOLETE configurations and files
4204 Configurations that have been declared obsolete in this release have
4205 been commented out. Unless there is activity to revive these
4206 configurations, the next release of GDB will have their sources
4207 permanently REMOVED.
4216 *** Changes in GDB 6.2.1:
4218 * MIPS `break main; run' gave an heuristic-fence-post warning
4220 When attempting to run even a simple program, a warning about
4221 heuristic-fence-post being hit would be reported. This problem has
4224 * MIPS IRIX 'long double' crashed GDB
4226 When examining a long double variable, GDB would get a segmentation
4227 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4228 IRIX long double values).
4232 A bug in the VAX stack code was causing problems with the "next"
4233 command. This problem has been fixed.
4235 *** Changes in GDB 6.2:
4237 * Fix for ``many threads''
4239 On GNU/Linux systems that use the NPTL threads library, a program
4240 rapidly creating and deleting threads would confuse GDB leading to the
4243 ptrace: No such process.
4244 thread_db_get_info: cannot get thread info: generic error
4246 This problem has been fixed.
4248 * "-async" and "-noasync" options removed.
4250 Support for the broken "-noasync" option has been removed (it caused
4253 * New ``start'' command.
4255 This command runs the program until the begining of the main procedure.
4257 * New BSD Kernel Data Access Library (libkvm) interface
4259 Using ``target kvm'' it is now possible to debug kernel core dumps and
4260 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4261 platforms. Currently supported (native-only) configurations are:
4263 FreeBSD/amd64 x86_64-*-freebsd*
4264 FreeBSD/i386 i?86-*-freebsd*
4265 NetBSD/i386 i?86-*-netbsd*
4266 NetBSD/m68k m68*-*-netbsd*
4267 NetBSD/sparc sparc-*-netbsd*
4268 OpenBSD/amd64 x86_64-*-openbsd*
4269 OpenBSD/i386 i?86-*-openbsd*
4270 OpenBSD/m68k m68*-openbsd*
4271 OpenBSD/sparc sparc-*-openbsd*
4273 * Signal trampoline code overhauled
4275 Many generic problems with GDB's signal handling code have been fixed.
4276 These include: backtraces through non-contiguous stacks; recognition
4277 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4278 call; backtrace through a signal trampoline; step into and out of
4279 signal handlers; and single-stepping in the signal trampoline.
4281 Please note that kernel bugs are a limiting factor here. These
4282 features have been shown to work on an s390 GNU/Linux system that
4283 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4285 * Cygwin support for DWARF 2 added.
4287 * New native configurations
4289 GNU/Linux/hppa hppa*-*-linux*
4290 OpenBSD/hppa hppa*-*-openbsd*
4291 OpenBSD/m68k m68*-*-openbsd*
4292 OpenBSD/m88k m88*-*-openbsd*
4293 OpenBSD/powerpc powerpc-*-openbsd*
4294 NetBSD/vax vax-*-netbsd*
4295 OpenBSD/vax vax-*-openbsd*
4297 * END-OF-LIFE frame compatibility module
4299 GDB's internal frame infrastructure has been completely rewritten.
4300 The new infrastructure making it possible to support key new features
4301 including DWARF 2 Call Frame Information. To aid in the task of
4302 migrating old configurations to this new infrastructure, a
4303 compatibility module, that allowed old configurations to continue to
4304 work, was also included.
4306 GDB 6.2 will be the last release to include this frame compatibility
4307 module. This change directly impacts the following configurations:
4317 Unless there is activity to revive these configurations, they will be
4318 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4320 * REMOVED configurations and files
4322 Sun 3, running SunOS 3 m68*-*-sunos3*
4323 Sun 3, running SunOS 4 m68*-*-sunos4*
4324 Sun 2, running SunOS 3 m68000-*-sunos3*
4325 Sun 2, running SunOS 4 m68000-*-sunos4*
4326 Motorola 680x0 running LynxOS m68*-*-lynxos*
4327 AT&T 3b1/Unix pc m68*-att-*
4328 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4329 decstation mips-dec-* mips-little-*
4330 riscos mips-*-riscos* mips-*-sysv*
4331 sonymips mips-sony-*
4332 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4334 *** Changes in GDB 6.1.1:
4336 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4338 The TUI (Text-mode User Interface) is now built as part of a default
4339 GDB configuration. It is enabled by either selecting the TUI with the
4340 command line option "-i=tui" or by running the separate "gdbtui"
4341 program. For more information on the TUI, see the manual "Debugging
4344 * Pending breakpoint support (also included in GDB 6.1)
4346 Support has been added to allow you to specify breakpoints in shared
4347 libraries that have not yet been loaded. If a breakpoint location
4348 cannot be found, and the "breakpoint pending" option is set to auto,
4349 GDB queries you if you wish to make the breakpoint pending on a future
4350 shared-library load. If and when GDB resolves the breakpoint symbol,
4351 the pending breakpoint is removed as one or more regular breakpoints
4354 Pending breakpoints are very useful for GCJ Java debugging.
4356 * Fixed ISO-C build problems
4358 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4359 non ISO-C code that stopped them being built using a more strict ISO-C
4360 compiler (e.g., IBM's C compiler).
4362 * Fixed build problem on IRIX 5
4364 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4365 wasn't able to compile compile on an IRIX 5 system.
4367 * Added execute permission to gdb/gdbserver/configure
4369 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4370 permission. This bug would cause configure to fail on a number of
4371 systems (Solaris, IRIX). Ref: server/519.
4373 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4375 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4376 has been updated to use constant array sizes.
4378 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4380 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4381 its generated DWARF Call Frame Info. This encoding was causing GDB to
4382 panic, that panic has been fixed. Ref: gdb/1628.
4384 * Fixed a problem when examining parameters in shared library code.
4386 When examining parameters in optimized shared library code generated
4387 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4388 not available''. GDB now correctly displays the variable's value.
4390 *** Changes in GDB 6.1:
4392 * Removed --with-mmalloc
4394 Support for the mmalloc memory manager has been removed, as it
4395 conflicted with the internal gdb byte cache.
4397 * Changes in AMD64 configurations
4399 The AMD64 target now includes the %cs and %ss registers. As a result
4400 the AMD64 remote protocol has changed; this affects the floating-point
4401 and SSE registers. If you rely on those registers for your debugging,
4402 you should upgrade gdbserver on the remote side.
4404 * Revised SPARC target
4406 The SPARC target has been completely revised, incorporating the
4407 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4408 support for LynxOS and SunOS 4 has been dropped. Calling functions
4409 from within GDB on operating systems with a non-executable stack
4410 (Solaris, OpenBSD) now works.
4414 GDB has a new C++ demangler which does a better job on the mangled
4415 names generated by current versions of g++. It also runs faster, so
4416 with this and other changes gdb should now start faster on large C++
4419 * DWARF 2 Location Expressions
4421 GDB support for location expressions has been extended to support function
4422 arguments and frame bases. Older versions of GDB could crash when they
4425 * C++ nested types and namespaces
4427 GDB's support for nested types and namespaces in C++ has been
4428 improved, especially if you use the DWARF 2 debugging format. (This
4429 is the default for recent versions of GCC on most platforms.)
4430 Specifically, if you have a class "Inner" defined within a class or
4431 namespace "Outer", then GDB realizes that the class's name is
4432 "Outer::Inner", not simply "Inner". This should greatly reduce the
4433 frequency of complaints about not finding RTTI symbols. In addition,
4434 if you are stopped at inside of a function defined within a namespace,
4435 GDB modifies its name lookup accordingly.
4437 * New native configurations
4439 NetBSD/amd64 x86_64-*-netbsd*
4440 OpenBSD/amd64 x86_64-*-openbsd*
4441 OpenBSD/alpha alpha*-*-openbsd*
4442 OpenBSD/sparc sparc-*-openbsd*
4443 OpenBSD/sparc64 sparc64-*-openbsd*
4445 * New debugging protocols
4447 M32R with SDI protocol m32r-*-elf*
4449 * "set prompt-escape-char" command deleted.
4451 The command "set prompt-escape-char" has been deleted. This command,
4452 and its very obscure effet on GDB's prompt, was never documented,
4453 tested, nor mentioned in the NEWS file.
4455 * OBSOLETE configurations and files
4457 Configurations that have been declared obsolete in this release have
4458 been commented out. Unless there is activity to revive these
4459 configurations, the next release of GDB will have their sources
4460 permanently REMOVED.
4462 Sun 3, running SunOS 3 m68*-*-sunos3*
4463 Sun 3, running SunOS 4 m68*-*-sunos4*
4464 Sun 2, running SunOS 3 m68000-*-sunos3*
4465 Sun 2, running SunOS 4 m68000-*-sunos4*
4466 Motorola 680x0 running LynxOS m68*-*-lynxos*
4467 AT&T 3b1/Unix pc m68*-att-*
4468 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4469 decstation mips-dec-* mips-little-*
4470 riscos mips-*-riscos* mips-*-sysv*
4471 sonymips mips-sony-*
4472 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4474 * REMOVED configurations and files
4476 SGI Irix-4.x mips-sgi-irix4 or iris4
4477 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4478 Z8000 simulator z8k-zilog-none or z8ksim
4479 Matsushita MN10200 w/simulator mn10200-*-*
4480 H8/500 simulator h8500-hitachi-hms or h8500hms
4481 HP/PA running BSD hppa*-*-bsd*
4482 HP/PA running OSF/1 hppa*-*-osf*
4483 HP/PA Pro target hppa*-*-pro*
4484 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4485 386BSD i[3456]86-*-bsd*
4486 Sequent family i[3456]86-sequent-sysv4*
4487 i[3456]86-sequent-sysv*
4488 i[3456]86-sequent-bsd*
4489 SPARC running LynxOS sparc-*-lynxos*
4490 SPARC running SunOS 4 sparc-*-sunos4*
4491 Tsqware Sparclet sparclet-*-*
4492 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4494 *** Changes in GDB 6.0:
4498 Support for debugging the Objective-C programming language has been
4499 integrated into GDB.
4501 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4503 DWARF 2's Call Frame Information makes available compiler generated
4504 information that more exactly describes the program's run-time stack.
4505 By using this information, GDB is able to provide more robust stack
4508 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4509 have been updated to use a new backtrace mechanism which includes
4510 DWARF 2 CFI support.
4514 GDB's remote protocol has been extended to include support for hosted
4515 file I/O (where the remote target uses GDB's file system). See GDB's
4516 remote protocol documentation for details.
4518 * All targets using the new architecture framework.
4520 All of GDB's targets have been updated to use the new internal
4521 architecture framework. The way is now open for future GDB releases
4522 to include cross-architecture native debugging support (i386 on amd64,
4525 * GNU/Linux's Thread Local Storage (TLS)
4527 GDB now includes support for for the GNU/Linux implementation of
4528 per-thread variables.
4530 * GNU/Linux's Native POSIX Thread Library (NPTL)
4532 GDB's thread code has been updated to work with either the new
4533 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4535 * Separate debug info.
4537 GDB, in conjunction with BINUTILS, now supports a mechanism for
4538 automatically loading debug information from a separate file. Instead
4539 of shipping full debug and non-debug versions of system libraries,
4540 system integrators can now instead ship just the stripped libraries
4541 and optional debug files.
4543 * DWARF 2 Location Expressions
4545 DWARF 2 Location Expressions allow the compiler to more completely
4546 describe the location of variables (even in optimized code) to the
4549 GDB now includes preliminary support for location expressions (support
4550 for DW_OP_piece is still missing).
4554 A number of long standing bugs that caused GDB to die while starting a
4555 Java application have been fixed. GDB's Java support is now
4556 considered "useable".
4558 * GNU/Linux support for fork, vfork, and exec.
4560 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4561 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4564 * GDB supports logging output to a file
4566 There are two new commands, "set logging" and "show logging", which can be
4567 used to capture GDB's output to a file.
4569 * The meaning of "detach" has changed for gdbserver
4571 The "detach" command will now resume the application, as documented. To
4572 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4575 * d10v, m68hc11 `regs' command deprecated
4577 The `info registers' command has been updated so that it displays the
4578 registers using a format identical to the old `regs' command.
4582 A new command, "maint set profile on/off", has been added. This command can
4583 be used to enable or disable profiling while running GDB, to profile a
4584 session or a set of commands. In addition there is a new configure switch,
4585 "--enable-profiling", which will cause GDB to be compiled with profiling
4586 data, for more informative profiling results.
4588 * Default MI syntax changed to "mi2".
4590 The default MI (machine interface) syntax, enabled by the command line
4591 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4592 "mi1", can be enabled by specifying the option "-i=mi1".
4594 Support for the original "mi0" syntax (included in GDB 5.0) has been
4597 Fix for gdb/192: removed extraneous space when displaying frame level.
4598 Fix for gdb/672: update changelist is now output in mi list format.
4599 Fix for gdb/702: a -var-assign that updates the value now shows up
4600 in a subsequent -var-update.
4602 * New native configurations.
4604 FreeBSD/amd64 x86_64-*-freebsd*
4606 * Multi-arched targets.
4608 HP/PA HPUX11 hppa*-*-hpux*
4609 Renesas M32R/D w/simulator m32r-*-elf*
4611 * OBSOLETE configurations and files
4613 Configurations that have been declared obsolete in this release have
4614 been commented out. Unless there is activity to revive these
4615 configurations, the next release of GDB will have their sources
4616 permanently REMOVED.
4618 Z8000 simulator z8k-zilog-none or z8ksim
4619 Matsushita MN10200 w/simulator mn10200-*-*
4620 H8/500 simulator h8500-hitachi-hms or h8500hms
4621 HP/PA running BSD hppa*-*-bsd*
4622 HP/PA running OSF/1 hppa*-*-osf*
4623 HP/PA Pro target hppa*-*-pro*
4624 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4625 Sequent family i[3456]86-sequent-sysv4*
4626 i[3456]86-sequent-sysv*
4627 i[3456]86-sequent-bsd*
4628 Tsqware Sparclet sparclet-*-*
4629 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4631 * REMOVED configurations and files
4634 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4635 IBM AIX PS/2 i[3456]86-*-aix
4636 i386 running Mach 3.0 i[3456]86-*-mach3*
4637 i386 running Mach i[3456]86-*-mach*
4638 i386 running OSF/1 i[3456]86-*osf1mk*
4639 HP/Apollo 68k Family m68*-apollo*-sysv*,
4641 m68*-hp-bsd*, m68*-hp-hpux*
4642 Argonaut Risc Chip (ARC) arc-*-*
4643 Mitsubishi D30V d30v-*-*
4644 Fujitsu FR30 fr30-*-elf*
4645 OS/9000 i[34]86-*-os9k
4646 I960 with MON960 i960-*-coff
4648 * MIPS $fp behavior changed
4650 The convenience variable $fp, for the MIPS, now consistently returns
4651 the address of the current frame's base. Previously, depending on the
4652 context, $fp could refer to either $sp or the current frame's base
4653 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4654 The GNU Source-Level Debugger''.
4656 *** Changes in GDB 5.3:
4658 * GNU/Linux shared library multi-threaded performance improved.
4660 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4661 `/proc', in preference to `ptrace' for memory reads. This may result
4662 in an improvement in the start-up time of multi-threaded, shared
4663 library applications when run under GDB. One GDB user writes: ``loads
4664 shared libs like mad''.
4666 * ``gdbserver'' now supports multi-threaded applications on some targets
4668 Support for debugging multi-threaded applications which use
4669 the GNU/Linux LinuxThreads package has been added for
4670 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4671 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4673 * GDB now supports C/C++ preprocessor macros.
4675 GDB now expands preprocessor macro invocations in C/C++ expressions,
4676 and provides various commands for showing macro definitions and how
4679 The new command `macro expand EXPRESSION' expands any macro
4680 invocations in expression, and shows the result.
4682 The new command `show macro MACRO-NAME' shows the definition of the
4683 macro named MACRO-NAME, and where it was defined.
4685 Most compilers don't include information about macros in the debugging
4686 information by default. In GCC 3.1, for example, you need to compile
4687 your program with the options `-gdwarf-2 -g3'. If the macro
4688 information is present in the executable, GDB will read it.
4690 * Multi-arched targets.
4692 DEC Alpha (partial) alpha*-*-*
4693 DEC VAX (partial) vax-*-*
4695 National Semiconductor NS32000 (partial) ns32k-*-*
4696 Motorola 68000 (partial) m68k-*-*
4697 Motorola MCORE mcore-*-*
4701 Fujitsu FRV architecture added by Red Hat frv*-*-*
4704 * New native configurations
4706 Alpha NetBSD alpha*-*-netbsd*
4707 SH NetBSD sh*-*-netbsdelf*
4708 MIPS NetBSD mips*-*-netbsd*
4709 UltraSPARC NetBSD sparc64-*-netbsd*
4711 * OBSOLETE configurations and files
4713 Configurations that have been declared obsolete in this release have
4714 been commented out. Unless there is activity to revive these
4715 configurations, the next release of GDB will have their sources
4716 permanently REMOVED.
4718 Mitsubishi D30V d30v-*-*
4719 OS/9000 i[34]86-*-os9k
4720 IBM AIX PS/2 i[3456]86-*-aix
4721 Fujitsu FR30 fr30-*-elf*
4722 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4723 Argonaut Risc Chip (ARC) arc-*-*
4724 i386 running Mach 3.0 i[3456]86-*-mach3*
4725 i386 running Mach i[3456]86-*-mach*
4726 i386 running OSF/1 i[3456]86-*osf1mk*
4727 HP/Apollo 68k Family m68*-apollo*-sysv*,
4729 m68*-hp-bsd*, m68*-hp-hpux*
4730 I960 with MON960 i960-*-coff
4732 * OBSOLETE languages
4734 CHILL, a Pascal like language used by telecommunications companies.
4736 * REMOVED configurations and files
4738 AMD 29k family via UDI a29k-amd-udi, udi29k
4739 A29K VxWorks a29k-*-vxworks
4740 AMD 29000 embedded, using EBMON a29k-none-none
4741 AMD 29000 embedded with COFF a29k-none-coff
4742 AMD 29000 embedded with a.out a29k-none-aout
4744 testsuite/gdb.hp/gdb.threads-hp/ directory
4746 * New command "set max-user-call-depth <nnn>"
4748 This command allows the user to limit the call depth of user-defined
4749 commands. The default is 1024.
4751 * Changes in FreeBSD/i386 native debugging.
4753 Support for the "generate-core-file" has been added.
4755 * New commands "dump", "append", and "restore".
4757 These commands allow data to be copied from target memory
4758 to a bfd-format or binary file (dump and append), and back
4759 from a file into memory (restore).
4761 * Improved "next/step" support on multi-processor Alpha Tru64.
4763 The previous single-step mechanism could cause unpredictable problems,
4764 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4765 of a software single-step mechanism prevents this.
4767 *** Changes in GDB 5.2.1:
4775 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4776 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4777 Fix, by Joel Brobecker imported from mainline.
4779 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4780 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4781 Fix, by Fred Fish, imported from mainline.
4783 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4784 Surprisingly enough, it works now.
4785 By Michal Ludvig, imported from mainline.
4787 i386 hardware watchpoint support:
4788 avoid misses on second run for some targets.
4789 By Pierre Muller, imported from mainline.
4791 *** Changes in GDB 5.2:
4793 * New command "set trust-readonly-sections on[off]".
4795 This command is a hint that tells gdb that read-only sections
4796 really are read-only (ie. that their contents will not change).
4797 In this mode, gdb will go to the object file rather than the
4798 target to read memory from read-only sections (such as ".text").
4799 This can be a significant performance improvement on some
4800 (notably embedded) targets.
4802 * New command "generate-core-file" (or "gcore").
4804 This new gdb command allows the user to drop a core file of the child
4805 process state at any time. So far it's been implemented only for
4806 GNU/Linux and Solaris, but should be relatively easily ported to other
4807 hosts. Argument is core file name (defaults to core.<pid>).
4809 * New command line option
4811 GDB now accepts --pid or -p followed by a process id.
4813 * Change in command line behavior -- corefiles vs. process ids.
4815 There is a subtle behavior in the way in which GDB handles
4816 command line arguments. The first non-flag argument is always
4817 a program to debug, but the second non-flag argument may either
4818 be a corefile or a process id. Previously, GDB would attempt to
4819 open the second argument as a corefile, and if that failed, would
4820 issue a superfluous error message and then attempt to attach it as
4821 a process. Now, if the second argument begins with a non-digit,
4822 it will be treated as a corefile. If it begins with a digit,
4823 GDB will attempt to attach it as a process, and if no such process
4824 is found, will then attempt to open it as a corefile.
4826 * Changes in ARM configurations.
4828 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4829 configuration is fully multi-arch.
4831 * New native configurations
4833 ARM NetBSD arm*-*-netbsd*
4834 x86 OpenBSD i[3456]86-*-openbsd*
4835 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4836 Sparc64 running FreeBSD sparc64-*-freebsd*
4840 Sanyo XStormy16 xstormy16-elf
4842 * OBSOLETE configurations and files
4844 Configurations that have been declared obsolete in this release have
4845 been commented out. Unless there is activity to revive these
4846 configurations, the next release of GDB will have their sources
4847 permanently REMOVED.
4849 AMD 29k family via UDI a29k-amd-udi, udi29k
4850 A29K VxWorks a29k-*-vxworks
4851 AMD 29000 embedded, using EBMON a29k-none-none
4852 AMD 29000 embedded with COFF a29k-none-coff
4853 AMD 29000 embedded with a.out a29k-none-aout
4855 testsuite/gdb.hp/gdb.threads-hp/ directory
4857 * REMOVED configurations and files
4859 TI TMS320C80 tic80-*-*
4861 PowerPC Solaris powerpcle-*-solaris*
4862 PowerPC Windows NT powerpcle-*-cygwin32
4863 PowerPC Netware powerpc-*-netware*
4864 Harris/CXUX m88k m88*-harris-cxux*
4865 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4866 ns32k-utek-sysv* ns32k-utek-*
4867 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4868 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4869 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4870 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4871 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4873 * Changes to command line processing
4875 The new `--args' feature can be used to specify command-line arguments
4876 for the inferior from gdb's command line.
4878 * Changes to key bindings
4880 There is a new `operate-and-get-next' function bound to `C-o'.
4882 *** Changes in GDB 5.1.1
4884 Fix compile problem on DJGPP.
4886 Fix a problem with floating-point registers on the i386 being
4889 Fix to stop GDB crashing on .debug_str debug info.
4891 Numerous documentation fixes.
4893 Numerous testsuite fixes.
4895 *** Changes in GDB 5.1:
4897 * New native configurations
4899 Alpha FreeBSD alpha*-*-freebsd*
4900 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4901 MIPS GNU/Linux mips*-*-linux*
4902 MIPS SGI Irix 6.x mips*-sgi-irix6*
4903 ia64 AIX ia64-*-aix*
4904 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4908 Motorola 68HC11 and 68HC12 m68hc11-elf
4910 UltraSparc running GNU/Linux sparc64-*-linux*
4912 * OBSOLETE configurations and files
4914 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4915 Harris/CXUX m88k m88*-harris-cxux*
4916 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4917 ns32k-utek-sysv* ns32k-utek-*
4918 TI TMS320C80 tic80-*-*
4920 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4921 PowerPC Solaris powerpcle-*-solaris*
4922 PowerPC Windows NT powerpcle-*-cygwin32
4923 PowerPC Netware powerpc-*-netware*
4924 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4925 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4926 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4927 Apple Macintosh (MPW) host N/A
4929 stuff.c (Program to stuff files into a specially prepared space in kdb)
4930 kdb-start.c (Main loop for the standalone kernel debugger)
4932 Configurations that have been declared obsolete in this release have
4933 been commented out. Unless there is activity to revive these
4934 configurations, the next release of GDB will have their sources
4935 permanently REMOVED.
4937 * REMOVED configurations and files
4939 Altos 3068 m68*-altos-*
4940 Convex c1-*-*, c2-*-*
4942 ARM RISCix arm-*-* (as host)
4946 * GDB has been converted to ISO C.
4948 GDB's source code has been converted to ISO C. In particular, the
4949 sources are fully protoized, and rely on standard headers being
4954 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4956 * The MI enabled by default.
4958 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4959 revised and enabled by default. Packages which use GDB as a debugging
4960 engine behind a UI or another front end are encouraged to switch to
4961 using the GDB/MI interface, instead of the old annotations interface
4962 which is now deprecated.
4964 * Support for debugging Pascal programs.
4966 GDB now includes support for debugging Pascal programs. The following
4967 main features are supported:
4969 - Pascal-specific data types such as sets;
4971 - automatic recognition of Pascal sources based on file-name
4974 - Pascal-style display of data types, variables, and functions;
4976 - a Pascal expression parser.
4978 However, some important features are not yet supported.
4980 - Pascal string operations are not supported at all;
4982 - there are some problems with boolean types;
4984 - Pascal type hexadecimal constants are not supported
4985 because they conflict with the internal variables format;
4987 - support for Pascal objects and classes is not full yet;
4989 - unlike Pascal, GDB is case-sensitive for symbol names.
4991 * Changes in completion.
4993 Commands such as `shell', `run' and `set args', which pass arguments
4994 to inferior programs, now complete on file names, similar to what
4995 users expect at the shell prompt.
4997 Commands which accept locations, such as `disassemble', `print',
4998 `breakpoint', `until', etc. now complete on filenames as well as
4999 program symbols. Thus, if you type "break foob TAB", and the source
5000 files linked into the programs include `foobar.c', that file name will
5001 be one of the candidates for completion. However, file names are not
5002 considered for completion after you typed a colon that delimits a file
5003 name from a name of a function in that file, as in "break foo.c:bar".
5005 `set demangle-style' completes on available demangling styles.
5007 * New platform-independent commands:
5009 It is now possible to define a post-hook for a command as well as a
5010 hook that runs before the command. For more details, see the
5011 documentation of `hookpost' in the GDB manual.
5013 * Changes in GNU/Linux native debugging.
5015 Support for debugging multi-threaded programs has been completely
5016 revised for all platforms except m68k and sparc. You can now debug as
5017 many threads as your system allows you to have.
5019 Attach/detach is supported for multi-threaded programs.
5021 Support for SSE registers was added for x86. This doesn't work for
5022 multi-threaded programs though.
5024 * Changes in MIPS configurations.
5026 Multi-arch support is enabled for all MIPS configurations.
5028 GDB can now be built as native debugger on SGI Irix 6.x systems for
5029 debugging n32 executables. (Debugging 64-bit executables is not yet
5032 * Unified support for hardware watchpoints in all x86 configurations.
5034 Most (if not all) native x86 configurations support hardware-assisted
5035 breakpoints and watchpoints in a unified manner. This support
5036 implements debug register sharing between watchpoints, which allows to
5037 put a virtually infinite number of watchpoints on the same address,
5038 and also supports watching regions up to 16 bytes with several debug
5041 The new maintenance command `maintenance show-debug-regs' toggles
5042 debugging print-outs in functions that insert, remove, and test
5043 watchpoints and hardware breakpoints.
5045 * Changes in the DJGPP native configuration.
5047 New command ``info dos sysinfo'' displays assorted information about
5048 the CPU, OS, memory, and DPMI server.
5050 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5051 display information about segment descriptors stored in GDT, LDT, and
5054 New commands ``info dos pde'' and ``info dos pte'' display entries
5055 from Page Directory and Page Tables (for now works with CWSDPMI only).
5056 New command ``info dos address-pte'' displays the Page Table entry for
5057 a given linear address.
5059 GDB can now pass command lines longer than 126 characters to the
5060 program being debugged (requires an update to the libdbg.a library
5061 which is part of the DJGPP development kit).
5063 DWARF2 debug info is now supported.
5065 It is now possible to `step' and `next' through calls to `longjmp'.
5067 * Changes in documentation.
5069 All GDB documentation was converted to GFDL, the GNU Free
5070 Documentation License.
5072 Tracepoints-related commands are now fully documented in the GDB
5075 TUI, the Text-mode User Interface, is now documented in the manual.
5077 Tracepoints-related commands are now fully documented in the GDB
5080 The "GDB Internals" manual now has an index. It also includes
5081 documentation of `ui_out' functions, GDB coding standards, x86
5082 hardware watchpoints, and memory region attributes.
5084 * GDB's version number moved to ``version.in''
5086 The Makefile variable VERSION has been replaced by the file
5087 ``version.in''. People creating GDB distributions should update the
5088 contents of this file.
5092 GUD support is now a standard part of the EMACS distribution.
5094 *** Changes in GDB 5.0:
5096 * Improved support for debugging FP programs on x86 targets
5098 Unified and much-improved support for debugging floating-point
5099 programs on all x86 targets. In particular, ``info float'' now
5100 displays the FP registers in the same format on all x86 targets, with
5101 greater level of detail.
5103 * Improvements and bugfixes in hardware-assisted watchpoints
5105 It is now possible to watch array elements, struct members, and
5106 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5107 on x86 targets no longer erroneously trigger when the address is
5110 * Improvements in the native DJGPP version of GDB
5112 The distribution now includes all the scripts and auxiliary files
5113 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5114 machines ``out of the box''.
5116 The DJGPP version can now debug programs that use signals. It is
5117 possible to catch signals that happened in the debuggee, deliver
5118 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5119 would kill the program being debugged.) Programs that hook hardware
5120 interrupts (keyboard, timer, etc.) can also be debugged.
5122 It is now possible to debug DJGPP programs that redirect their
5123 standard handles or switch them to raw (as opposed to cooked) mode, or
5124 even close them. The command ``run < foo > bar'' works as expected,
5125 and ``info terminal'' reports useful information about the debuggee's
5126 terminal, including raw/cooked mode, redirection, etc.
5128 The DJGPP version now uses termios functions for console I/O, which
5129 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5132 DOS-style file names with drive letters are now fully supported by
5135 It is now possible to debug DJGPP programs that switch their working
5136 directory. It is also possible to rerun the debuggee any number of
5137 times without restarting GDB; thus, you can use the same setup,
5138 breakpoints, etc. for many debugging sessions.
5140 * New native configurations
5142 ARM GNU/Linux arm*-*-linux*
5143 PowerPC GNU/Linux powerpc-*-linux*
5147 Motorola MCore mcore-*-*
5148 x86 VxWorks i[3456]86-*-vxworks*
5149 PowerPC VxWorks powerpc-*-vxworks*
5150 TI TMS320C80 tic80-*-*
5152 * OBSOLETE configurations
5154 Altos 3068 m68*-altos-*
5155 Convex c1-*-*, c2-*-*
5157 ARM RISCix arm-*-* (as host)
5160 Configurations that have been declared obsolete will be commented out,
5161 but the code will be left in place. If there is no activity to revive
5162 these configurations before the next release of GDB, the sources will
5163 be permanently REMOVED.
5165 * Gould support removed
5167 Support for the Gould PowerNode and NP1 has been removed.
5169 * New features for SVR4
5171 On SVR4 native platforms (such as Solaris), if you attach to a process
5172 without first loading a symbol file, GDB will now attempt to locate and
5173 load symbols from the running process's executable file.
5175 * Many C++ enhancements
5177 C++ support has been greatly improved. Overload resolution now works properly
5178 in almost all cases. RTTI support is on the way.
5180 * Remote targets can connect to a sub-program
5182 A popen(3) style serial-device has been added. This device starts a
5183 sub-process (such as a stand-alone simulator) and then communicates
5184 with that. The sub-program to run is specified using the syntax
5185 ``|<program> <args>'' vis:
5187 (gdb) set remotedebug 1
5188 (gdb) target extended-remote |mn10300-elf-sim program-args
5190 * MIPS 64 remote protocol
5192 A long standing bug in the mips64 remote protocol where by GDB
5193 expected certain 32 bit registers (ex SR) to be transfered as 32
5194 instead of 64 bits has been fixed.
5196 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5197 added to provide backward compatibility with older versions of GDB.
5199 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5201 The command ``set remotebinarydownload'' command has been replaced by
5202 ``set remote X-packet''. Other commands in ``set remote'' family
5203 include ``set remote P-packet''.
5205 * Breakpoint commands accept ranges.
5207 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5208 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5209 ``tracepoint passcount'' also accepts a range of tracepoints.
5211 * ``apropos'' command added.
5213 The ``apropos'' command searches through command names and
5214 documentation strings, printing out matches, making it much easier to
5215 try to find a command that does what you are looking for.
5219 A new machine oriented interface (MI) has been added to GDB. This
5220 interface is designed for debug environments running GDB as a separate
5221 process. This is part of the long term libGDB project. See the
5222 "GDB/MI" chapter of the GDB manual for further information. It can be
5223 enabled by configuring with:
5225 .../configure --enable-gdbmi
5227 *** Changes in GDB-4.18:
5229 * New native configurations
5231 HP-UX 10.20 hppa*-*-hpux10.20
5232 HP-UX 11.x hppa*-*-hpux11.0*
5233 M68K GNU/Linux m68*-*-linux*
5237 Fujitsu FR30 fr30-*-elf*
5238 Intel StrongARM strongarm-*-*
5239 Mitsubishi D30V d30v-*-*
5241 * OBSOLETE configurations
5243 Gould PowerNode, NP1 np1-*-*, pn-*-*
5245 Configurations that have been declared obsolete will be commented out,
5246 but the code will be left in place. If there is no activity to revive
5247 these configurations before the next release of GDB, the sources will
5248 be permanently REMOVED.
5252 As a compatibility experiment, GDB's source files buildsym.h and
5253 buildsym.c have been converted to pure standard C, no longer
5254 containing any K&R compatibility code. We believe that all systems in
5255 use today either come with a standard C compiler, or have a GCC port
5256 available. If this is not true, please report the affected
5257 configuration to bug-gdb@gnu.org immediately. See the README file for
5258 information about getting a standard C compiler if you don't have one
5263 GDB now uses readline 2.2.
5265 * set extension-language
5267 You can now control the mapping between filename extensions and source
5268 languages by using the `set extension-language' command. For instance,
5269 you can ask GDB to treat .c files as C++ by saying
5270 set extension-language .c c++
5271 The command `info extensions' lists all of the recognized extensions
5272 and their associated languages.
5274 * Setting processor type for PowerPC and RS/6000
5276 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5277 you can use the `set processor' command to specify what variant of the
5278 PowerPC family you are debugging. The command
5282 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5283 following PowerPC and RS6000 variants:
5285 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5286 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5288 403GC IBM PowerPC 403GC
5289 505 Motorola PowerPC 505
5290 860 Motorola PowerPC 860 or 850
5291 601 Motorola PowerPC 601
5292 602 Motorola PowerPC 602
5293 603 Motorola/IBM PowerPC 603 or 603e
5294 604 Motorola PowerPC 604 or 604e
5295 750 Motorola/IBM PowerPC 750 or 750
5297 At the moment, this command just tells GDB what to name the
5298 special-purpose processor registers. Since almost all the affected
5299 registers are inaccessible to user-level programs, this command is
5300 only useful for remote debugging in its present form.
5304 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5305 more extensive support for HP-UX. Added features include shared
5306 library support, kernel threads and hardware watchpoints for 11.00,
5307 support for HP's ANSI C and C++ compilers, and a compatibility mode
5308 for xdb and dbx commands.
5312 HP's donation includes the new concept of catchpoints, which is a
5313 generalization of the old catch command. On HP-UX, it is now possible
5314 to catch exec, fork, and vfork, as well as library loading.
5316 This means that the existing catch command has changed; its first
5317 argument now specifies the type of catch to be set up. See the
5318 output of "help catch" for a list of catchpoint types.
5320 * Debugging across forks
5322 On HP-UX, you can choose which process to debug when a fork() happens
5327 HP has donated a curses-based terminal user interface (TUI). To get
5328 it, build with --enable-tui. Although this can be enabled for any
5329 configuration, at present it only works for native HP debugging.
5331 * GDB remote protocol additions
5333 A new protocol packet 'X' that writes binary data is now available.
5334 Default behavior is to try 'X', then drop back to 'M' if the stub
5335 fails to respond. The settable variable `remotebinarydownload'
5336 allows explicit control over the use of 'X'.
5338 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5339 full 64-bit address. The command
5341 set remoteaddresssize 32
5343 can be used to revert to the old behaviour. For existing remote stubs
5344 the change should not be noticed, as the additional address information
5347 In order to assist in debugging stubs, you may use the maintenance
5348 command `packet' to send any text string to the stub. For instance,
5350 maint packet heythere
5352 sends the packet "$heythere#<checksum>". Note that it is very easy to
5353 disrupt a debugging session by sending the wrong packet at the wrong
5356 The compare-sections command allows you to compare section data on the
5357 target to what is in the executable file without uploading or
5358 downloading, by comparing CRC checksums.
5360 * Tracing can collect general expressions
5362 You may now collect general expressions at tracepoints. This requires
5363 further additions to the target-side stub; see tracepoint.c and
5364 doc/agentexpr.texi for further details.
5366 * mask-address variable for Mips
5368 For Mips targets, you may control the zeroing of the upper 32 bits of
5369 a 64-bit address by entering `set mask-address on'. This is mainly
5370 of interest to users of embedded R4xxx and R5xxx processors.
5372 * Higher serial baud rates
5374 GDB's serial code now allows you to specify baud rates 57600, 115200,
5375 230400, and 460800 baud. (Note that your host system may not be able
5376 to achieve all of these rates.)
5380 The i960 configuration now includes an initial implementation of a
5381 builtin simulator, contributed by Jim Wilson.
5384 *** Changes in GDB-4.17:
5386 * New native configurations
5388 Alpha GNU/Linux alpha*-*-linux*
5389 Unixware 2.x i[3456]86-unixware2*
5390 Irix 6.x mips*-sgi-irix6*
5391 PowerPC GNU/Linux powerpc-*-linux*
5392 PowerPC Solaris powerpcle-*-solaris*
5393 Sparc GNU/Linux sparc-*-linux*
5394 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5398 Argonaut Risc Chip (ARC) arc-*-*
5399 Hitachi H8/300S h8300*-*-*
5400 Matsushita MN10200 w/simulator mn10200-*-*
5401 Matsushita MN10300 w/simulator mn10300-*-*
5402 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5403 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5404 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5405 Mitsubishi D10V w/simulator d10v-*-*
5406 Mitsubishi M32R/D w/simulator m32r-*-elf*
5407 Tsqware Sparclet sparclet-*-*
5408 NEC V850 w/simulator v850-*-*
5410 * New debugging protocols
5412 ARM with RDI protocol arm*-*-*
5413 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5414 DDB and LSI variants of PMON protocol mips*-*-*
5415 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5416 PowerPC with SDS protocol powerpc{,le}-*-eabi
5417 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5421 All configurations can now understand and use the DWARF 2 debugging
5422 format. The choice is automatic, if the symbol file contains DWARF 2
5427 GDB now includes basic Java language support. This support is
5428 only useful with Java compilers that produce native machine code.
5430 * solib-absolute-prefix and solib-search-path
5432 For SunOS and SVR4 shared libraries, you may now set the prefix for
5433 loading absolute shared library symbol files, and the search path for
5434 locating non-absolute shared library symbol files.
5436 * Live range splitting
5438 GDB can now effectively debug code for which GCC has performed live
5439 range splitting as part of its optimization. See gdb/doc/LRS for
5440 more details on the expected format of the stabs information.
5444 GDB's support for the GNU Hurd, including thread debugging, has been
5445 updated to work with current versions of the Hurd.
5449 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5450 instruction set. ARM GDB automatically detects when Thumb
5451 instructions are in use, and adjusts disassembly and backtracing
5456 GDB's MIPS target configurations now handle the MIP16 16-bit
5461 GDB now includes support for overlays; if an executable has been
5462 linked such that multiple sections are based at the same address, GDB
5463 will decide which section to use for symbolic info. You can choose to
5464 control the decision manually, using overlay commands, or implement
5465 additional target-side support and use "overlay load-target" to bring
5466 in the overlay mapping. Do "help overlay" for more detail.
5470 The command "info symbol <address>" displays information about
5471 the symbol at the specified address.
5475 The standard remote protocol now includes an extension that allows
5476 asynchronous collection and display of trace data. This requires
5477 extensive support in the target-side debugging stub. Tracing mode
5478 includes a new interaction mode in GDB and new commands: see the
5479 file tracepoint.c for more details.
5483 Configurations for embedded MIPS now include a simulator contributed
5484 by Cygnus Solutions. The simulator supports the instruction sets
5485 of most MIPS variants.
5489 Sparc configurations may now include the ERC32 simulator contributed
5490 by the European Space Agency. The simulator is not built into
5491 Sparc targets by default; configure with --enable-sim to include it.
5495 For target configurations that may include multiple variants of a
5496 basic architecture (such as MIPS and SH), you may now set the
5497 architecture explicitly. "set arch" sets, "info arch" lists
5498 the possible architectures.
5500 *** Changes in GDB-4.16:
5502 * New native configurations
5504 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5505 M68K NetBSD m68k-*-netbsd*
5506 PowerPC AIX 4.x powerpc-*-aix*
5507 PowerPC MacOS powerpc-*-macos*
5508 PowerPC Windows NT powerpcle-*-cygwin32
5509 RS/6000 AIX 4.x rs6000-*-aix4*
5513 ARM with RDP protocol arm-*-*
5514 I960 with MON960 i960-*-coff
5515 MIPS VxWorks mips*-*-vxworks*
5516 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5517 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5519 Matra Sparclet sparclet-*-*
5523 The powerpc-eabi configuration now includes the PSIM simulator,
5524 contributed by Andrew Cagney, with assistance from Mike Meissner.
5525 PSIM is a very elaborate model of the PowerPC, including not only
5526 basic instruction set execution, but also details of execution unit
5527 performance and I/O hardware. See sim/ppc/README for more details.
5531 GDB now works with Solaris 2.5.
5533 * Windows 95/NT native
5535 GDB will now work as a native debugger on Windows 95 and Windows NT.
5536 To build it from source, you must use the "gnu-win32" environment,
5537 which uses a DLL to emulate enough of Unix to run the GNU tools.
5538 Further information, binaries, and sources are available at
5539 ftp.cygnus.com, under pub/gnu-win32.
5541 * dont-repeat command
5543 If a user-defined command includes the command `dont-repeat', then the
5544 command will not be repeated if the user just types return. This is
5545 useful if the command is time-consuming to run, so that accidental
5546 extra keystrokes don't run the same command many times.
5548 * Send break instead of ^C
5550 The standard remote protocol now includes an option to send a break
5551 rather than a ^C to the target in order to interrupt it. By default,
5552 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5554 * Remote protocol timeout
5556 The standard remote protocol includes a new variable `remotetimeout'
5557 that allows you to set the number of seconds before GDB gives up trying
5558 to read from the target. The default value is 2.
5560 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5562 By default GDB will automatically keep track of objects as they are
5563 loaded and unloaded by the dynamic linker. By using the command `set
5564 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5565 when shared library events occur, thus allowing you to set breakpoints
5566 in shared libraries which are explicitly loaded by the inferior.
5568 Note this feature does not work on hpux8. On hpux9 you must link
5569 /usr/lib/end.o into your program. This feature should work
5570 automatically on hpux10.
5572 * Irix 5.x hardware watchpoint support
5574 Irix 5 configurations now support the use of hardware watchpoints.
5576 * Mips protocol "SYN garbage limit"
5578 When debugging a Mips target using the `target mips' protocol, you
5579 may set the number of characters that GDB will ignore by setting
5580 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5581 every character. The default value is 1050.
5583 * Recording and replaying remote debug sessions
5585 If you set `remotelogfile' to the name of a file, gdb will write to it
5586 a recording of a remote debug session. This recording may then be
5587 replayed back to gdb using "gdbreplay". See gdbserver/README for
5588 details. This is useful when you have a problem with GDB while doing
5589 remote debugging; you can make a recording of the session and send it
5590 to someone else, who can then recreate the problem.
5592 * Speedups for remote debugging
5594 GDB includes speedups for downloading and stepping MIPS systems using
5595 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5596 and more efficient S-record downloading.
5598 * Memory use reductions and statistics collection
5600 GDB now uses less memory and reports statistics about memory usage.
5601 Try the `maint print statistics' command, for example.
5603 *** Changes in GDB-4.15:
5605 * Psymtabs for XCOFF
5607 The symbol reader for AIX GDB now uses partial symbol tables. This
5608 can greatly improve startup time, especially for large executables.
5610 * Remote targets use caching
5612 Remote targets now use a data cache to speed up communication with the
5613 remote side. The data cache could lead to incorrect results because
5614 it doesn't know about volatile variables, thus making it impossible to
5615 debug targets which use memory mapped I/O devices. `set remotecache
5616 off' turns the the data cache off.
5618 * Remote targets may have threads
5620 The standard remote protocol now includes support for multiple threads
5621 in the target system, using new protocol commands 'H' and 'T'. See
5622 gdb/remote.c for details.
5626 If GDB is configured with `--enable-netrom', then it will include
5627 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5628 acts as though it is a bank of ROM on the target board, but you can
5629 write into it over the network. GDB's support consists only of
5630 support for fast loading into the emulated ROM; to debug, you must use
5631 another protocol, such as standard remote protocol. The usual
5632 sequence is something like
5634 target nrom <netrom-hostname>
5636 target remote <netrom-hostname>:1235
5640 GDB now includes support for the Apple Macintosh, as a host only. It
5641 may be run as either an MPW tool or as a standalone application, and
5642 it can debug through the serial port. All the usual GDB commands are
5643 available, but to the target command, you must supply "serial" as the
5644 device type instead of "/dev/ttyXX". See mpw-README in the main
5645 directory for more information on how to build. The MPW configuration
5646 scripts */mpw-config.in support only a few targets, and only the
5647 mips-idt-ecoff target has been tested.
5651 GDB configuration now uses autoconf. This is not user-visible,
5652 but does simplify configuration and building.
5656 GDB now supports hpux10.
5658 *** Changes in GDB-4.14:
5660 * New native configurations
5662 x86 FreeBSD i[345]86-*-freebsd
5663 x86 NetBSD i[345]86-*-netbsd
5664 NS32k NetBSD ns32k-*-netbsd
5665 Sparc NetBSD sparc-*-netbsd
5669 A29K VxWorks a29k-*-vxworks
5670 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5671 CPU32 EST-300 emulator m68*-*-est*
5672 PowerPC ELF powerpc-*-elf
5675 * Alpha OSF/1 support for procfs
5677 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5678 possible to attach to running processes. As the mounting of the /proc
5679 filesystem is optional on the Alpha, GDB automatically determines
5680 the availability of /proc during startup. This can lead to problems
5681 if /proc is unmounted after GDB has been started.
5683 * Arguments to user-defined commands
5685 User commands may accept up to 10 arguments separated by whitespace.
5686 Arguments are accessed within the user command via $arg0..$arg9. A
5689 print $arg0 + $arg1 + $arg2
5691 To execute the command use:
5694 Defines the command "adder" which prints the sum of its three arguments.
5695 Note the arguments are text substitutions, so they may reference variables,
5696 use complex expressions, or even perform inferior function calls.
5698 * New `if' and `while' commands
5700 This makes it possible to write more sophisticated user-defined
5701 commands. Both commands take a single argument, which is the
5702 expression to evaluate, and must be followed by the commands to
5703 execute, one per line, if the expression is nonzero, the list being
5704 terminated by the word `end'. The `if' command list may include an
5705 `else' word, which causes the following commands to be executed only
5706 if the expression is zero.
5708 * Fortran source language mode
5710 GDB now includes partial support for Fortran 77. It will recognize
5711 Fortran programs and can evaluate a subset of Fortran expressions, but
5712 variables and functions may not be handled correctly. GDB will work
5713 with G77, but does not yet know much about symbols emitted by other
5716 * Better HPUX support
5718 Most debugging facilities now work on dynamic executables for HPPAs
5719 running hpux9 or later. You can attach to running dynamically linked
5720 processes, but by default the dynamic libraries will be read-only, so
5721 for instance you won't be able to put breakpoints in them. To change
5722 that behavior do the following before running the program:
5728 This will cause the libraries to be mapped private and read-write.
5729 To revert to the normal behavior, do this:
5735 You cannot set breakpoints or examine data in the library until after
5736 the library is loaded if the function/data symbols do not have
5739 GDB can now also read debug symbols produced by the HP C compiler on
5740 HPPAs (sorry, no C++, Fortran or 68k support).
5742 * Target byte order now dynamically selectable
5744 You can choose which byte order to use with a target system, via the
5745 commands "set endian big" and "set endian little", and you can see the
5746 current setting by using "show endian". You can also give the command
5747 "set endian auto", in which case GDB will use the byte order
5748 associated with the executable. Currently, only embedded MIPS
5749 configurations support dynamic selection of target byte order.
5751 * New DOS host serial code
5753 This version uses DPMI interrupts to handle buffered I/O, so you
5754 no longer need to run asynctsr when debugging boards connected to
5757 *** Changes in GDB-4.13:
5759 * New "complete" command
5761 This lists all the possible completions for the rest of the line, if it
5762 were to be given as a command itself. This is intended for use by emacs.
5764 * Trailing space optional in prompt
5766 "set prompt" no longer adds a space for you after the prompt you set. This
5767 allows you to set a prompt which ends in a space or one that does not.
5769 * Breakpoint hit counts
5771 "info break" now displays a count of the number of times the breakpoint
5772 has been hit. This is especially useful in conjunction with "ignore"; you
5773 can ignore a large number of breakpoint hits, look at the breakpoint info
5774 to see how many times the breakpoint was hit, then run again, ignoring one
5775 less than that number, and this will get you quickly to the last hit of
5778 * Ability to stop printing at NULL character
5780 "set print null-stop" will cause GDB to stop printing the characters of
5781 an array when the first NULL is encountered. This is useful when large
5782 arrays actually contain only short strings.
5784 * Shared library breakpoints
5786 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5787 breakpoints in shared libraries before the executable is run.
5789 * Hardware watchpoints
5791 There is a new hardware breakpoint for the watch command for sparclite
5792 targets. See gdb/sparclite/hw_breakpoint.note.
5794 Hardware watchpoints are also now supported under GNU/Linux.
5798 Annotations have been added. These are for use with graphical interfaces,
5799 and are still experimental. Currently only gdba.el uses these.
5801 * Improved Irix 5 support
5803 GDB now works properly with Irix 5.2.
5805 * Improved HPPA support
5807 GDB now works properly with the latest GCC and GAS.
5809 * New native configurations
5811 Sequent PTX4 i[34]86-sequent-ptx4
5812 HPPA running OSF/1 hppa*-*-osf*
5813 Atari TT running SVR4 m68*-*-sysv4*
5814 RS/6000 LynxOS rs6000-*-lynxos*
5818 OS/9000 i[34]86-*-os9k
5819 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5822 * Hitachi SH7000 and E7000-PC ICE support
5824 There is now support for communicating with the Hitachi E7000-PC ICE.
5825 This is available automatically when GDB is configured for the SH.
5829 As usual, a variety of small fixes and improvements, both generic
5830 and configuration-specific. See the ChangeLog for more detail.
5832 *** Changes in GDB-4.12:
5834 * Irix 5 is now supported
5838 GDB-4.12 on the HPPA has a number of changes which make it unable
5839 to debug the output from the currently released versions of GCC and
5840 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5841 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5842 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5845 *** Changes in GDB-4.11:
5847 * User visible changes:
5851 The "set remotedebug" option is now consistent between the mips remote
5852 target, remote targets using the gdb-specific protocol, UDI (AMD's
5853 debug protocol for the 29k) and the 88k bug monitor. It is now an
5854 integer specifying a debug level (normally 0 or 1, but 2 means more
5855 debugging info for the mips target).
5857 * DEC Alpha native support
5859 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5860 debug info, but GDB works fairly well with the DEC compiler and should
5861 work with a future GCC release. See the README file for a few
5862 Alpha-specific notes.
5864 * Preliminary thread implementation
5866 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5868 * LynxOS native and target support for 386
5870 This release has been hosted on LynxOS 2.2, and also can be configured
5871 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5874 * Improvements in C++ mangling/demangling.
5876 This release has much better g++ debugging, specifically in name
5877 mangling/demangling, virtual function calls, print virtual table,
5878 call methods, ...etc.
5880 *** Changes in GDB-4.10:
5882 * User visible changes:
5884 Remote debugging using the GDB-specific (`target remote') protocol now
5885 supports the `load' command. This is only useful if you have some
5886 other way of getting the stub to the target system, and you can put it
5887 somewhere in memory where it won't get clobbered by the download.
5889 Filename completion now works.
5891 When run under emacs mode, the "info line" command now causes the
5892 arrow to point to the line specified. Also, "info line" prints
5893 addresses in symbolic form (as well as hex).
5895 All vxworks based targets now support a user settable option, called
5896 vxworks-timeout. This option represents the number of seconds gdb
5897 should wait for responses to rpc's. You might want to use this if
5898 your vxworks target is, perhaps, a slow software simulator or happens
5899 to be on the far side of a thin network line.
5903 This release contains support for using a DEC alpha as a GDB host for
5904 cross debugging. Native alpha debugging is not supported yet.
5907 *** Changes in GDB-4.9:
5911 This is the first GDB release which is accompanied by a matching testsuite.
5912 The testsuite requires installation of dejagnu, which should be available
5913 via ftp from most sites that carry GNU software.
5917 'Cfront' style demangling has had its name changed to 'ARM' style, to
5918 emphasize that it was written from the specifications in the C++ Annotated
5919 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5920 disclaimers, it still generated too much confusion with users attempting to
5921 use gdb with AT&T cfront.
5925 GDB now uses a standard remote interface to a simulator library.
5926 So far, the library contains simulators for the Zilog Z8001/2, the
5927 Hitachi H8/300, H8/500 and Super-H.
5929 * New targets supported
5931 H8/300 simulator h8300-hitachi-hms or h8300hms
5932 H8/500 simulator h8500-hitachi-hms or h8500hms
5933 SH simulator sh-hitachi-hms or sh
5934 Z8000 simulator z8k-zilog-none or z8ksim
5935 IDT MIPS board over serial line mips-idt-ecoff
5937 Cross-debugging to GO32 targets is supported. It requires a custom
5938 version of the i386-stub.c module which is integrated with the
5939 GO32 memory extender.
5941 * New remote protocols
5943 MIPS remote debugging protocol.
5945 * New source languages supported
5947 This version includes preliminary support for Chill, a Pascal like language
5948 used by telecommunications companies. Chill support is also being integrated
5949 into the GNU compiler, but we don't know when it will be publically available.
5952 *** Changes in GDB-4.8:
5954 * HP Precision Architecture supported
5956 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5957 version of this support was available as a set of patches from the
5958 University of Utah. GDB does not support debugging of programs
5959 compiled with the HP compiler, because HP will not document their file
5960 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5961 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5963 Many problems in the preliminary version have been fixed.
5965 * Faster and better demangling
5967 We have improved template demangling and fixed numerous bugs in the GNU style
5968 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5969 character types (wchar_t) are now supported. Demangling of each symbol is now
5970 only done once, and is cached when the symbol table for a file is read in.
5971 This results in a small increase in memory usage for C programs, a moderate
5972 increase in memory usage for C++ programs, and a fantastic speedup in
5975 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5976 from the specifications in the Annotated Reference Manual, which AT&T's
5977 compiler does not actually implement.
5979 * G++ multiple inheritance compiler problem
5981 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5982 inheritance lattices was reworked to properly discover ambiguities. We
5983 recently found an example which causes this new algorithm to fail in a
5984 very subtle way, producing bad debug information for those classes.
5985 The file 'gcc.patch' (in this directory) can be applied to gcc to
5986 circumvent the problem. A future GCC release will contain a complete
5989 The previous G++ debug info problem (mentioned below for the gdb-4.7
5990 release) is fixed in gcc version 2.3.2.
5992 * Improved configure script
5994 The `configure' script will now attempt to guess your system type if
5995 you don't supply a host system type. The old scheme of supplying a
5996 host system triplet is preferable over using this. All the magic is
5997 done in the new `config.guess' script. Examine it for details.
5999 We have also brought our configure script much more in line with the FSF's
6000 version. It now supports the --with-xxx options. In particular,
6001 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6002 The resulting GDB will not be able to read arbitrary object file formats --
6003 only the format ``expected'' to be used on the configured target system.
6004 We hope to make this the default in a future release.
6006 * Documentation improvements
6008 There's new internal documentation on how to modify GDB, and how to
6009 produce clean changes to the code. We implore people to read it
6010 before submitting changes.
6012 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6013 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6014 `info' files are also provided. To build `info' files from scratch,
6015 you will need the latest `makeinfo' release, which will be available in
6016 a future texinfo-X.Y release.
6018 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6019 We're not sure exactly which versions have this problem, but it has
6020 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6021 or better. If that isn't possible, there is a patch in
6022 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6023 around this problem.
6027 GDB now supports array constants that can be used in expressions typed in by
6028 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6029 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6032 The new directory `gdb/sparclite' contains a program that demonstrates
6033 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6035 * New native hosts supported
6037 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6038 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6040 * New targets supported
6042 AMD 29k family via UDI a29k-amd-udi or udi29k
6044 * New file formats supported
6046 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6047 HPUX core files, and SCO 3.2v2 core files.
6051 Attaching to processes now works again; thanks for the many bug reports.
6053 We have also stomped on a bunch of core dumps caused by
6054 printf_filtered("%s") problems.
6056 We eliminated a copyright problem on the rpc and ptrace header files
6057 for VxWorks, which was discovered at the last minute during the 4.7
6058 release. You should now be able to build a VxWorks GDB.
6060 You can now interrupt gdb while an attached process is running. This
6061 will cause the attached process to stop, and give control back to GDB.
6063 We fixed problems caused by using too many file descriptors
6064 for reading symbols from object files and libraries. This was
6065 especially a problem for programs that used many (~100) shared
6068 The `step' command now only enters a subroutine if there is line number
6069 information for the subroutine. Otherwise it acts like the `next'
6070 command. Previously, `step' would enter subroutines if there was
6071 any debugging information about the routine. This avoids problems
6072 when using `cc -g1' on MIPS machines.
6074 * Internal improvements
6076 GDB's internal interfaces have been improved to make it easier to support
6077 debugging of multiple languages in the future.
6079 GDB now uses a common structure for symbol information internally.
6080 Minimal symbols (derived from linkage symbols in object files), partial
6081 symbols (from a quick scan of debug information), and full symbols
6082 contain a common subset of information, making it easier to write
6083 shared code that handles any of them.
6085 * New command line options
6087 We now accept --silent as an alias for --quiet.
6091 The memory-mapped-malloc library is now licensed under the GNU Library
6092 General Public License.
6094 *** Changes in GDB-4.7:
6096 * Host/native/target split
6098 GDB has had some major internal surgery to untangle the support for
6099 hosts and remote targets. Now, when you configure GDB for a remote
6100 target, it will no longer load in all of the support for debugging
6101 local programs on the host. When fully completed and tested, this will
6102 ensure that arbitrary host/target combinations are possible.
6104 The primary conceptual shift is to separate the non-portable code in
6105 GDB into three categories. Host specific code is required any time GDB
6106 is compiled on that host, regardless of the target. Target specific
6107 code relates to the peculiarities of the target, but can be compiled on
6108 any host. Native specific code is everything else: it can only be
6109 built when the host and target are the same system. Child process
6110 handling and core file support are two common `native' examples.
6112 GDB's use of /proc for controlling Unix child processes is now cleaner.
6113 It has been split out into a single module under the `target_ops' vector,
6114 plus two native-dependent functions for each system that uses /proc.
6116 * New hosts supported
6118 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6119 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6120 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6122 * New targets supported
6124 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6125 68030 and CPU32 m68030-*-*, m68332-*-*
6127 * New native hosts supported
6129 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6130 (386bsd is not well tested yet)
6131 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6133 * New file formats supported
6135 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6136 supports reading of `a.out.adobe' object files, which are an a.out
6137 format extended with minimal information about multiple sections.
6141 `show copying' is the same as the old `info copying'.
6142 `show warranty' is the same as `info warrantee'.
6143 These were renamed for consistency. The old commands continue to work.
6145 `info handle' is a new alias for `info signals'.
6147 You can now define pre-command hooks, which attach arbitrary command
6148 scripts to any command. The commands in the hook will be executed
6149 prior to the user's command. You can also create a hook which will be
6150 executed whenever the program stops. See gdb.texinfo.
6154 We now deal with Cfront style name mangling, and can even extract type
6155 info from mangled symbols. GDB can automatically figure out which
6156 symbol mangling style your C++ compiler uses.
6158 Calling of methods and virtual functions has been improved as well.
6162 The crash that occured when debugging Sun Ansi-C compiled binaries is
6163 fixed. This was due to mishandling of the extra N_SO stabs output
6166 We also finally got Ultrix 4.2 running in house, and fixed core file
6167 support, with help from a dozen people on the net.
6169 John M. Farrell discovered that the reason that single-stepping was so
6170 slow on all of the Mips based platforms (primarily SGI and DEC) was
6171 that we were trying to demangle and lookup a symbol used for internal
6172 purposes on every instruction that was being stepped through. Changing
6173 the name of that symbol so that it couldn't be mistaken for a C++
6174 mangled symbol sped things up a great deal.
6176 Rich Pixley sped up symbol lookups in general by getting much smarter
6177 about when C++ symbol mangling is necessary. This should make symbol
6178 completion (TAB on the command line) much faster. It's not as fast as
6179 we'd like, but it's significantly faster than gdb-4.6.
6183 A new user controllable variable 'call_scratch_address' can
6184 specify the location of a scratch area to be used when GDB
6185 calls a function in the target. This is necessary because the
6186 usual method of putting the scratch area on the stack does not work
6187 in systems that have separate instruction and data spaces.
6189 We integrated changes to support the 29k UDI (Universal Debugger
6190 Interface), but discovered at the last minute that we didn't have all
6191 of the appropriate copyright paperwork. We are working with AMD to
6192 resolve this, and hope to have it available soon.
6196 We have sped up the remote serial line protocol, especially for targets
6197 with lots of registers. It now supports a new `expedited status' ('T')
6198 message which can be used in place of the existing 'S' status message.
6199 This allows the remote stub to send only the registers that GDB
6200 needs to make a quick decision about single-stepping or conditional
6201 breakpoints, eliminating the need to fetch the entire register set for
6202 each instruction being stepped through.
6204 The GDB remote serial protocol now implements a write-through cache for
6205 registers, only re-reading the registers if the target has run.
6207 There is also a new remote serial stub for SPARC processors. You can
6208 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6209 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6210 processor with a serial port.
6214 Configure.in files have become much easier to read and modify. A new
6215 `table driven' format makes it more obvious what configurations are
6216 supported, and what files each one uses.
6220 There is a new opcodes library which will eventually contain all of the
6221 disassembly routines and opcode tables. At present, it only contains
6222 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6223 disassembler (binutils/objdump) to share these routines.
6225 The libiberty library is now copylefted under the GNU Library General
6226 Public License. This allows more liberal use, and was done so libg++
6227 can use it. This makes no difference to GDB, since the Library License
6228 grants all the rights from the General Public License.
6232 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6233 reference to the stabs symbol info used by the debugger. It is (as far
6234 as we know) the only published document on this fascinating topic. We
6235 encourage you to read it, compare it to the stabs information on your
6236 system, and send improvements on the document in general (to
6237 bug-gdb@prep.ai.mit.edu).
6239 And, of course, many bugs have been fixed.
6242 *** Changes in GDB-4.6:
6244 * Better support for C++ function names
6246 GDB now accepts as input the "demangled form" of C++ overloaded function
6247 names and member function names, and can do command completion on such names
6248 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6249 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6250 Make use of command completion, it is your friend.
6252 GDB also now accepts a variety of C++ mangled symbol formats. They are
6253 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6254 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6255 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6256 for the list of formats.
6258 * G++ symbol mangling problem
6260 Recent versions of gcc have a bug in how they emit debugging information for
6261 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6262 directory) can be applied to gcc to fix the problem. Alternatively, if you
6263 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6264 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6265 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6268 * New 'maintenance' command
6270 All of the commands related to hacking GDB internals have been moved out of
6271 the main command set, and now live behind the 'maintenance' command. This
6272 can also be abbreviated as 'mt'. The following changes were made:
6274 dump-me -> maintenance dump-me
6275 info all-breakpoints -> maintenance info breakpoints
6276 printmsyms -> maintenance print msyms
6277 printobjfiles -> maintenance print objfiles
6278 printpsyms -> maintenance print psymbols
6279 printsyms -> maintenance print symbols
6281 The following commands are new:
6283 maintenance demangle Call internal GDB demangler routine to
6284 demangle a C++ link name and prints the result.
6285 maintenance print type Print a type chain for a given symbol
6287 * Change to .gdbinit file processing
6289 We now read the $HOME/.gdbinit file before processing the argv arguments
6290 (e.g. reading symbol files or core files). This allows global parameters to
6291 be set, which will apply during the symbol reading. The ./.gdbinit is still
6292 read after argv processing.
6294 * New hosts supported
6296 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6298 GNU/Linux support i386-unknown-linux or linux
6300 We are also including code to support the HP/PA running BSD and HPUX. This
6301 is almost guaranteed not to work, as we didn't have time to test or build it
6302 for this release. We are including it so that the more adventurous (or
6303 masochistic) of you can play with it. We also had major problems with the
6304 fact that the compiler that we got from HP doesn't support the -g option.
6307 * New targets supported
6309 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6311 * More smarts about finding #include files
6313 GDB now remembers the compilation directory for all include files, and for
6314 all files from which C is generated (like yacc and lex sources). This
6315 greatly improves GDB's ability to find yacc/lex sources, and include files,
6316 especially if you are debugging your program from a directory different from
6317 the one that contains your sources.
6319 We also fixed a bug which caused difficulty with listing and setting
6320 breakpoints in include files which contain C code. (In the past, you had to
6321 try twice in order to list an include file that you hadn't looked at before.)
6323 * Interesting infernals change
6325 GDB now deals with arbitrary numbers of sections, where the symbols for each
6326 section must be relocated relative to that section's landing place in the
6327 target's address space. This work was needed to support ELF with embedded
6328 stabs used by Solaris-2.0.
6330 * Bug fixes (of course!)
6332 There have been loads of fixes for the following things:
6333 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6334 i960, stabs, DOS(GO32), procfs, etc...
6336 See the ChangeLog for details.
6338 *** Changes in GDB-4.5:
6340 * New machines supported (host and target)
6342 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6344 SGI Irix-4.x mips-sgi-irix4 or iris4
6346 * New malloc package
6348 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6349 Mmalloc is capable of handling mutiple heaps of memory. It is also
6350 capable of saving a heap to a file, and then mapping it back in later.
6351 This can be used to greatly speedup the startup of GDB by using a
6352 pre-parsed symbol table which lives in a mmalloc managed heap. For
6353 more details, please read mmalloc/mmalloc.texi.
6357 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6358 'help info proc' for details.
6360 * MIPS ecoff symbol table format
6362 The code that reads MIPS symbol table format is now supported on all hosts.
6363 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6366 * File name changes for MS-DOS
6368 Many files in the config directories have been renamed to make it easier to
6369 support GDB on MS-DOSe systems (which have very restrictive file name
6370 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6371 environment) is close to working but has some remaining problems. Note
6372 that debugging of DOS programs is not supported, due to limitations
6373 in the ``operating system'', but it can be used to host cross-debugging.
6375 * Cross byte order fixes
6377 Many fixes have been made to support cross debugging of Sparc and MIPS
6378 targets from hosts whose byte order differs.
6380 * New -mapped and -readnow options
6382 If memory-mapped files are available on your system through the 'mmap'
6383 system call, you can use the -mapped option on the `file' or
6384 `symbol-file' commands to cause GDB to write the symbols from your
6385 program into a reusable file. If the program you are debugging is
6386 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6387 Future GDB debugging sessions will notice the presence of this file,
6388 and will quickly map in symbol information from it, rather than reading
6389 the symbol table from the executable program. Using the '-mapped'
6390 option in a GDB `file' or `symbol-file' command has the same effect as
6391 starting GDB with the '-mapped' command-line option.
6393 You can cause GDB to read the entire symbol table immediately by using
6394 the '-readnow' option with any of the commands that load symbol table
6395 information (or on the GDB command line). This makes the command
6396 slower, but makes future operations faster.
6398 The -mapped and -readnow options are typically combined in order to
6399 build a `fred.syms' file that contains complete symbol information.
6400 A simple GDB invocation to do nothing but build a `.syms' file for future
6403 gdb -batch -nx -mapped -readnow programname
6405 The `.syms' file is specific to the host machine on which GDB is run.
6406 It holds an exact image of GDB's internal symbol table. It cannot be
6407 shared across multiple host platforms.
6409 * longjmp() handling
6411 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6412 siglongjmp() without losing control. This feature has not yet been ported to
6413 all systems. It currently works on many 386 platforms, all MIPS-based
6414 platforms (SGI, DECstation, etc), and Sun3/4.
6418 Preliminary work has been put in to support the new Solaris OS from Sun. At
6419 this time, it can control and debug processes, but it is not capable of
6424 As always, many many bug fixes. The major areas were with g++, and mipsread.
6425 People using the MIPS-based platforms should experience fewer mysterious
6426 crashes and trashed symbol tables.
6428 *** Changes in GDB-4.4:
6430 * New machines supported (host and target)
6432 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6434 BSD Reno on Vax vax-dec-bsd
6435 Ultrix on Vax vax-dec-ultrix
6437 * New machines supported (target)
6439 AMD 29000 embedded, using EBMON a29k-none-none
6443 GDB continues to improve its handling of C++. `References' work better.
6444 The demangler has also been improved, and now deals with symbols mangled as
6445 per the Annotated C++ Reference Guide.
6447 GDB also now handles `stabs' symbol information embedded in MIPS
6448 `ecoff' symbol tables. Since the ecoff format was not easily
6449 extensible to handle new languages such as C++, this appeared to be a
6450 good way to put C++ debugging info into MIPS binaries. This option
6451 will be supported in the GNU C compiler, version 2, when it is
6454 * New features for SVR4
6456 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6457 shared libraries. Debugging dynamically linked programs should present
6458 only minor differences from debugging statically linked programs.
6460 The `info proc' command will print out information about any process
6461 on an SVR4 system (including the one you are debugging). At the moment,
6462 it prints the address mappings of the process.
6464 If you bring up GDB on another SVR4 system, please send mail to
6465 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6467 * Better dynamic linking support in SunOS
6469 Reading symbols from shared libraries which contain debugging symbols
6470 now works properly. However, there remain issues such as automatic
6471 skipping of `transfer vector' code during function calls, which
6472 make it harder to debug code in a shared library, than to debug the
6473 same code linked statically.
6477 GDB is now using the latest `getopt' routines from the FSF. This
6478 version accepts the -- prefix for options with long names. GDB will
6479 continue to accept the old forms (-option and +option) as well.
6480 Various single letter abbreviations for options have been explicity
6481 added to the option table so that they won't get overshadowed in the
6482 future by other options that begin with the same letter.
6486 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6487 Many assorted bugs have been handled. Many more remain to be handled.
6488 See the various ChangeLog files (primarily in gdb and bfd) for details.
6491 *** Changes in GDB-4.3:
6493 * New machines supported (host and target)
6495 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6496 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6497 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6499 * Almost SCO Unix support
6501 We had hoped to support:
6502 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6503 (except for core file support), but we discovered very late in the release
6504 that it has problems with process groups that render gdb unusable. Sorry
6505 about that. I encourage people to fix it and post the fixes.
6507 * Preliminary ELF and DWARF support
6509 GDB can read ELF object files on System V Release 4, and can handle
6510 debugging records for C, in DWARF format, in ELF files. This support
6511 is preliminary. If you bring up GDB on another SVR4 system, please
6512 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6517 GDB now uses the latest `readline' library. One user-visible change
6518 is that two tabs will list possible command completions, which previously
6519 required typing M-? (meta-question mark, or ESC ?).
6523 The `stepi' bug that many of you noticed has been squashed.
6524 Many bugs in C++ have been handled. Many more remain to be handled.
6525 See the various ChangeLog files (primarily in gdb and bfd) for details.
6527 * State of the MIPS world (in case you wondered):
6529 GDB can understand the symbol tables emitted by the compilers
6530 supplied by most vendors of MIPS-based machines, including DEC. These
6531 symbol tables are in a format that essentially nobody else uses.
6533 Some versions of gcc come with an assembler post-processor called
6534 mips-tfile. This program is required if you want to do source-level
6535 debugging of gcc-compiled programs. I believe FSF does not ship
6536 mips-tfile with gcc version 1, but it will eventually come with gcc
6539 Debugging of g++ output remains a problem. g++ version 1.xx does not
6540 really support it at all. (If you're lucky, you should be able to get
6541 line numbers and stack traces to work, but no parameters or local
6542 variables.) With some work it should be possible to improve the
6545 When gcc version 2 is released, you will have somewhat better luck.
6546 However, even then you will get confusing results for inheritance and
6549 We will eventually provide full debugging of g++ output on
6550 DECstations. This will probably involve some kind of stabs-in-ecoff
6551 encapulation, but the details have not been worked out yet.
6554 *** Changes in GDB-4.2:
6556 * Improved configuration
6558 Only one copy of `configure' exists now, and it is not self-modifying.
6559 Porting BFD is simpler.
6563 The `step' and `next' commands now only stop at the first instruction
6564 of a source line. This prevents the multiple stops that used to occur
6565 in switch statements, for-loops, etc. `Step' continues to stop if a
6566 function that has debugging information is called within the line.
6570 Lots of small bugs fixed. More remain.
6572 * New host supported (not target)
6574 Intel 386 PC clone running Mach i386-none-mach
6577 *** Changes in GDB-4.1:
6579 * Multiple source language support
6581 GDB now has internal scaffolding to handle several source languages.
6582 It determines the type of each source file from its filename extension,
6583 and will switch expression parsing and number formatting to match the
6584 language of the function in the currently selected stack frame.
6585 You can also specifically set the language to be used, with
6586 `set language c' or `set language modula-2'.
6590 GDB now has preliminary support for the GNU Modula-2 compiler,
6591 currently under development at the State University of New York at
6592 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6593 continue through the fall of 1991 and into 1992.
6595 Other Modula-2 compilers are currently not supported, and attempting to
6596 debug programs compiled with them will likely result in an error as the
6597 symbol table is read. Feel free to work on it, though!
6599 There are hooks in GDB for strict type checking and range checking,
6600 in the `Modula-2 philosophy', but they do not currently work.
6604 GDB can now write to executable and core files (e.g. patch
6605 a variable's value). You must turn this switch on, specify
6606 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6607 by assigning a new value to a variable. Modifications take
6610 * Automatic SunOS shared library reading
6612 When you run your program, GDB automatically determines where its
6613 shared libraries (if any) have been loaded, and reads their symbols.
6614 The `share' command is no longer needed. This also works when
6615 examining core files.
6619 You can specify the number of lines that the `list' command shows.
6622 * New machines supported (host and target)
6624 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6625 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6626 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6628 * New hosts supported (not targets)
6630 IBM RT/PC: romp-ibm-aix or rtpc
6632 * New targets supported (not hosts)
6634 AMD 29000 embedded with COFF a29k-none-coff
6635 AMD 29000 embedded with a.out a29k-none-aout
6636 Ultracomputer remote kernel debug a29k-nyu-kern
6638 * New remote interfaces
6644 *** Changes in GDB-4.0:
6648 Wide output is wrapped at good places to make the output more readable.
6650 Gdb now supports cross-debugging from a host machine of one type to a
6651 target machine of another type. Communication with the target system
6652 is over serial lines. The ``target'' command handles connecting to the
6653 remote system; the ``load'' command will download a program into the
6654 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6655 also supports debugging of realtime processes running under VxWorks,
6656 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6657 stub on the target system.
6659 New CPUs supported include the AMD 29000 and Intel 960.
6661 GDB now reads object files and symbol tables via a ``binary file''
6662 library, which allows a single copy of GDB to debug programs of multiple
6663 object file types such as a.out and coff.
6665 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6666 refcard.dvi and refcard.ps are available to format it).
6669 * Control-Variable user interface simplified
6671 All variables that control the operation of the debugger can be set
6672 by the ``set'' command, and displayed by the ``show'' command.
6674 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6675 ``Show prompt'' produces the response:
6676 Gdb's prompt is new-gdb=>.
6678 What follows are the NEW set commands. The command ``help set'' will
6679 print a complete list of old and new set commands. ``help set FOO''
6680 will give a longer description of the variable FOO. ``show'' will show
6681 all of the variable descriptions and their current settings.
6683 confirm on/off: Enables warning questions for operations that are
6684 hard to recover from, e.g. rerunning the program while
6685 it is already running. Default is ON.
6687 editing on/off: Enables EMACS style command line editing
6688 of input. Previous lines can be recalled with
6689 control-P, the current line can be edited with control-B,
6690 you can search for commands with control-R, etc.
6693 history filename NAME: NAME is where the gdb command history
6694 will be stored. The default is .gdb_history,
6695 or the value of the environment variable
6698 history size N: The size, in commands, of the command history. The
6699 default is 256, or the value of the environment variable
6702 history save on/off: If this value is set to ON, the history file will
6703 be saved after exiting gdb. If set to OFF, the
6704 file will not be saved. The default is OFF.
6706 history expansion on/off: If this value is set to ON, then csh-like
6707 history expansion will be performed on
6708 command line input. The default is OFF.
6710 radix N: Sets the default radix for input and output. It can be set
6711 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6712 in the current radix, so "set radix 10" is always a no-op.
6714 height N: This integer value is the number of lines on a page. Default
6715 is 24, the current `stty rows'' setting, or the ``li#''
6716 setting from the termcap entry matching the environment
6719 width N: This integer value is the number of characters on a line.
6720 Default is 80, the current `stty cols'' setting, or the ``co#''
6721 setting from the termcap entry matching the environment
6724 Note: ``set screensize'' is obsolete. Use ``set height'' and
6725 ``set width'' instead.
6727 print address on/off: Print memory addresses in various command displays,
6728 such as stack traces and structure values. Gdb looks
6729 more ``symbolic'' if you turn this off; it looks more
6730 ``machine level'' with it on. Default is ON.
6732 print array on/off: Prettyprint arrays. New convenient format! Default
6735 print demangle on/off: Print C++ symbols in "source" form if on,
6738 print asm-demangle on/off: Same, for assembler level printouts
6741 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6744 * Support for Epoch Environment.
6746 The epoch environment is a version of Emacs v18 with windowing. One
6747 new command, ``inspect'', is identical to ``print'', except that if you
6748 are running in the epoch environment, the value is printed in its own
6752 * Support for Shared Libraries
6754 GDB can now debug programs and core files that use SunOS shared libraries.
6755 Symbols from a shared library cannot be referenced
6756 before the shared library has been linked with the program (this
6757 happens after you type ``run'' and before the function main() is entered).
6758 At any time after this linking (including when examining core files
6759 from dynamically linked programs), gdb reads the symbols from each
6760 shared library when you type the ``sharedlibrary'' command.
6761 It can be abbreviated ``share''.
6763 sharedlibrary REGEXP: Load shared object library symbols for files
6764 matching a unix regular expression. No argument
6765 indicates to load symbols for all shared libraries.
6767 info sharedlibrary: Status of loaded shared libraries.
6772 A watchpoint stops execution of a program whenever the value of an
6773 expression changes. Checking for this slows down execution
6774 tremendously whenever you are in the scope of the expression, but is
6775 quite useful for catching tough ``bit-spreader'' or pointer misuse
6776 problems. Some machines such as the 386 have hardware for doing this
6777 more quickly, and future versions of gdb will use this hardware.
6779 watch EXP: Set a watchpoint (breakpoint) for an expression.
6781 info watchpoints: Information about your watchpoints.
6783 delete N: Deletes watchpoint number N (same as breakpoints).
6784 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6785 enable N: Re-enables watchpoint number N (same as breakpoints).
6788 * C++ multiple inheritance
6790 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6793 * C++ exception handling
6795 Gdb now supports limited C++ exception handling. Besides the existing
6796 ability to breakpoint on an exception handler, gdb can breakpoint on
6797 the raising of an exception (before the stack is peeled back to the
6800 catch FOO: If there is a FOO exception handler in the dynamic scope,
6801 set a breakpoint to catch exceptions which may be raised there.
6802 Multiple exceptions (``catch foo bar baz'') may be caught.
6804 info catch: Lists all exceptions which may be caught in the
6805 current stack frame.
6808 * Minor command changes
6810 The command ``call func (arg, arg, ...)'' now acts like the print
6811 command, except it does not print or save a value if the function's result
6812 is void. This is similar to dbx usage.
6814 The ``up'' and ``down'' commands now always print the frame they end up
6815 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6816 frames without printing.
6818 * New directory command
6820 'dir' now adds directories to the FRONT of the source search path.
6821 The path starts off empty. Source files that contain debug information
6822 about the directory in which they were compiled can be found even
6823 with an empty path; Sun CC and GCC include this information. If GDB can't
6824 find your source file in the current directory, type "dir .".
6826 * Configuring GDB for compilation
6828 For normal use, type ``./configure host''. See README or gdb.texinfo
6831 GDB now handles cross debugging. If you are remotely debugging between
6832 two different machines, type ``./configure host -target=targ''.
6833 Host is the machine where GDB will run; targ is the machine
6834 where the program that you are debugging will run.