1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now supports access to the guarded-storage-control registers and the
7 software-based guarded-storage broadcast control registers on IBM z14.
9 * On Unix systems, GDB now supports transmitting environment variables
10 that are to be set or unset to GDBserver. These variables will
11 affect the environment to be passed to the remote inferior.
13 To inform GDB of environment variables that are to be transmitted to
14 GDBserver, use the "set environment" command. Only user set
15 environment variables are sent to GDBserver.
17 To inform GDB of environment variables that are to be unset before
18 the remote inferior is started by the GDBserver, use the "unset
23 ** New events gdb.new_inferior, gdb.inferior_deleted, and
24 gdb.new_thread are emitted. See the manual for further
27 ** A new command, "rbreak" has been added to the Python API. This
28 command allows the setting of a large number of breakpoints via a
29 regex pattern in Python. See the manual for further details.
31 * New features in the GDB remote stub, GDBserver
33 ** GDBserver is now able to start inferior processes with a
34 specified initial working directory.
36 The user can set the desired working directory to be used from
37 GDB using the new "set cwd" command.
39 ** New "--selftest" command line option runs some GDBserver self
40 tests. These self tests are disabled in releases.
42 ** On Unix systems, GDBserver now does globbing expansion and variable
43 substitution in inferior command line arguments.
45 This is done by starting inferiors using a shell, like GDB does.
46 See "set startup-with-shell" in the user manual for how to disable
47 this from GDB when using "target extended-remote". When using
48 "target remote", you can disable the startup with shell by using the
49 new "--no-startup-with-shell" GDBserver command line option.
51 ** On Unix systems, GDBserver now supports receiving environment
52 variables that are to be set or unset from GDB. These variables
53 will affect the environment to be passed to the inferior.
57 QEnvironmentHexEncoded
58 Inform GDBserver of an environment variable that is to be passed to
59 the inferior when starting it.
62 Inform GDBserver of an environment variable that is to be unset
63 before starting the remote inferior.
66 Inform GDBserver that the environment should be reset (i.e.,
67 user-set environment variables should be unset).
70 Indicates whether the inferior must be started with a shell or not.
73 Tell GDBserver that the inferior to be started should use a specific
76 * The "maintenance print c-tdesc" command now takes an optional
77 argument which is the file name of XML target description.
79 * The "maintenance selftest" command now takes an optional argument to
80 filter the tests to be run.
82 * The "enable", and "disable" commands now accept a range of
83 breakpoint locations, e.g. "enable 1.3-5".
88 Set and show the current working directory for the inferior.
91 Set and show compilation command used for compiling and injecting code
92 with the 'compile' commands.
94 set debug separate-debug-file
95 show debug separate-debug-file
96 Control the display of debug output about separate debug file search.
99 List the registered selftests.
102 Start the debugged program stopping at the first instruction.
104 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
107 * Safer/improved support for debugging with no debug info
109 GDB no longer assumes functions with no debug information return
112 This means that GDB now refuses to call such functions unless you
113 tell it the function's type, by either casting the call to the
114 declared return type, or by casting the function to a function
115 pointer of the right type, and calling that:
117 (gdb) p getenv ("PATH")
118 'getenv' has unknown return type; cast the call to its declared return type
119 (gdb) p (char *) getenv ("PATH")
120 $1 = 0x7fffffffe "/usr/local/bin:/"...
121 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
122 $2 = 0x7fffffffe "/usr/local/bin:/"...
124 Similarly, GDB no longer assumes that global variables with no debug
125 info have type 'int', and refuses to print the variable's value
126 unless you tell it the variable's type:
129 'var' has unknown type; cast it to its declared type
133 * New native configurations
135 FreeBSD/aarch64 aarch64*-*-freebsd*
136 FreeBSD/arm arm*-*-freebsd*
140 FreeBSD/aarch64 aarch64*-*-freebsd*
141 FreeBSD/arm arm*-*-freebsd*
143 * Removed targets and native configurations
145 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
147 *** Changes in GDB 8.0
149 * GDB now supports access to the PKU register on GNU/Linux. The register is
150 added by the Memory Protection Keys for Userspace feature which will be
151 available in future Intel CPUs.
153 * GDB now supports C++11 rvalue references.
157 ** New functions to start, stop and access a running btrace recording.
158 ** Rvalue references are now supported in gdb.Type.
160 * GDB now supports recording and replaying rdrand and rdseed Intel 64
163 * Building GDB and GDBserver now requires a C++11 compiler.
165 For example, GCC 4.8 or later.
167 It is no longer possible to build GDB or GDBserver with a C
168 compiler. The --disable-build-with-cxx configure option has been
171 * Building GDB and GDBserver now requires GNU make >= 3.81.
173 It is no longer supported to build GDB or GDBserver with another
174 implementation of the make program or an earlier version of GNU make.
176 * Native debugging on MS-Windows supports command-line redirection
178 Command-line arguments used for starting programs on MS-Windows can
179 now include redirection symbols supported by native Windows shells,
180 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
181 as "run", "start", and "set args", as well as the corresponding MI
184 * Support for thread names on MS-Windows.
186 GDB now catches and handles the special exception that programs
187 running on MS-Windows use to assign names to threads in the
190 * Support for Java programs compiled with gcj has been removed.
192 * User commands now accept an unlimited number of arguments.
193 Previously, only up to 10 was accepted.
195 * The "eval" command now expands user-defined command arguments.
197 This makes it easier to process a variable number of arguments:
202 eval "print $arg%d", $i
207 * Target descriptions can now describe registers for sparc32 and sparc64.
209 * GDB now supports DWARF version 5 (debug information format).
210 Its .debug_names index is not yet supported.
212 * New native configurations
214 FreeBSD/mips mips*-*-freebsd
218 Synopsys ARC arc*-*-elf32
219 FreeBSD/mips mips*-*-freebsd
221 * Removed targets and native configurations
223 Alpha running FreeBSD alpha*-*-freebsd*
224 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
229 Erases all the flash memory regions reported by the target.
231 maint print arc arc-instruction address
232 Print internal disassembler information about instruction at a given address.
236 set disassembler-options
237 show disassembler-options
238 Controls the passing of target specific information to the disassembler.
239 If it is necessary to specify more than one disassembler option then
240 multiple options can be placed together into a comma separated list.
241 The default value is the empty string. Currently, the only supported
242 targets are ARM, PowerPC and S/390.
247 Erases all the flash memory regions reported by the target. This is
248 equivalent to the CLI command flash-erase.
250 -file-list-shared-libraries
251 List the shared libraries in the program. This is
252 equivalent to the CLI command "info shared".
254 *** Changes in GDB 7.12
256 * GDB and GDBserver now build with a C++ compiler by default.
258 The --enable-build-with-cxx configure option is now enabled by
259 default. One must now explicitly configure with
260 --disable-build-with-cxx in order to build with a C compiler. This
261 option will be removed in a future release.
263 * GDBserver now supports recording btrace without maintaining an active
266 * GDB now supports a negative repeat count in the 'x' command to examine
267 memory backward from the given address. For example:
270 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
271 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
272 (gdb) x/-5i 0x0000000000400580
273 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
274 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
275 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
276 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
277 0x40057b <main(int, char**)+25>:
278 callq 0x400536 <Func1(int, char const*)>
280 * Fortran: Support structures with fields of dynamic types and
281 arrays of dynamic types.
283 * The symbol dumping maintenance commands have new syntax.
284 maint print symbols [-pc address] [--] [filename]
285 maint print symbols [-objfile objfile] [-source source] [--] [filename]
286 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
287 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
288 maint print msymbols [-objfile objfile] [--] [filename]
290 * GDB now supports multibit bitfields and enums in target register
293 * New Python-based convenience function $_as_string(val), which returns
294 the textual representation of a value. This function is especially
295 useful to obtain the text label of an enum value.
297 * Intel MPX bound violation handling.
299 Segmentation faults caused by a Intel MPX boundary violation
300 now display the kind of violation (upper or lower), the memory
301 address accessed and the memory bounds, along with the usual
302 signal received and code location.
306 Program received signal SIGSEGV, Segmentation fault
307 Upper bound violation while accessing address 0x7fffffffc3b3
308 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
309 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
311 * Rust language support.
312 GDB now supports debugging programs written in the Rust programming
313 language. See https://www.rust-lang.org/ for more information about
316 * Support for running interpreters on specified input/output devices
318 GDB now supports a new mechanism that allows frontends to provide
319 fully featured GDB console views, as a better alternative to
320 building such views on top of the "-interpreter-exec console"
321 command. See the new "new-ui" command below. With that command,
322 frontends can now start GDB in the traditional command-line mode
323 running in an embedded terminal emulator widget, and create a
324 separate MI interpreter running on a specified i/o device. In this
325 way, GDB handles line editing, history, tab completion, etc. in the
326 console all by itself, and the GUI uses the separate MI interpreter
327 for its own control and synchronization, invisible to the command
330 * The "catch syscall" command catches groups of related syscalls.
332 The "catch syscall" command now supports catching a group of related
333 syscalls using the 'group:' or 'g:' prefix.
338 skip -gfile file-glob-pattern
339 skip -function function
340 skip -rfunction regular-expression
341 A generalized form of the skip command, with new support for
342 glob-style file names and regular expressions for function names.
343 Additionally, a file spec and a function spec may now be combined.
345 maint info line-table REGEXP
346 Display the contents of GDB's internal line table data struture.
349 Run any GDB unit tests that were compiled in.
352 Start a new user interface instance running INTERP as interpreter,
353 using the TTY file for input/output.
357 ** gdb.Breakpoint objects have a new attribute "pending", which
358 indicates whether the breakpoint is pending.
359 ** Three new breakpoint-related events have been added:
360 gdb.breakpoint_created, gdb.breakpoint_modified, and
361 gdb.breakpoint_deleted.
364 Signal ("set") the given MS-Windows event object. This is used in
365 conjunction with the Windows JIT debugging (AeDebug) support, where
366 the OS suspends a crashing process until a debugger can attach to
367 it. Resuming the crashing process, in order to debug it, is done by
370 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
371 was added in GDBserver, including JIT compiling fast tracepoint's
372 conditional expression bytecode into native code.
374 * Support for various remote target protocols and ROM monitors has
377 target m32rsdi Remote M32R debugging over SDI
378 target mips MIPS remote debugging protocol
379 target pmon PMON ROM monitor
380 target ddb NEC's DDB variant of PMON for Vr4300
381 target rockhopper NEC RockHopper variant of PMON
382 target lsi LSI variant of PMO
384 * Support for tracepoints and fast tracepoints on powerpc-linux,
385 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
386 including JIT compiling fast tracepoint's conditional expression
387 bytecode into native code.
389 * MI async record =record-started now includes the method and format used for
390 recording. For example:
392 =record-started,thread-group="i1",method="btrace",format="bts"
394 * MI async record =thread-selected now includes the frame field. For example:
396 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
400 Andes NDS32 nds32*-*-elf
402 *** Changes in GDB 7.11
404 * GDB now supports debugging kernel-based threads on FreeBSD.
406 * Per-inferior thread numbers
408 Thread numbers are now per inferior instead of global. If you're
409 debugging multiple inferiors, GDB displays thread IDs using a
410 qualified INF_NUM.THR_NUM form. For example:
414 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
415 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
416 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
417 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
419 As consequence, thread numbers as visible in the $_thread
420 convenience variable and in Python's InferiorThread.num attribute
421 are no longer unique between inferiors.
423 GDB now maintains a second thread ID per thread, referred to as the
424 global thread ID, which is the new equivalent of thread numbers in
425 previous releases. See also $_gthread below.
427 For backwards compatibility, MI's thread IDs always refer to global
430 * Commands that accept thread IDs now accept the qualified
431 INF_NUM.THR_NUM form as well. For example:
434 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
437 * In commands that accept a list of thread IDs, you can now refer to
438 all threads of an inferior using a star wildcard. GDB accepts
439 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
440 refer to all threads of the current inferior. For example, "info
443 * You can use "info threads -gid" to display the global thread ID of
446 * The new convenience variable $_gthread holds the global number of
449 * The new convenience variable $_inferior holds the number of the
452 * GDB now displays the ID and name of the thread that hit a breakpoint
453 or received a signal, if your program is multi-threaded. For
456 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
457 Thread 1 "main" received signal SIGINT, Interrupt.
459 * Record btrace now supports non-stop mode.
461 * Support for tracepoints on aarch64-linux was added in GDBserver.
463 * The 'record instruction-history' command now indicates speculative execution
464 when using the Intel Processor Trace recording format.
466 * GDB now allows users to specify explicit locations, bypassing
467 the linespec parser. This feature is also available to GDB/MI
470 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
471 GDB now is able to debug both AArch64 applications and ARM applications
474 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
475 including JIT compiling fast tracepoint's conditional expression bytecode
478 * GDB now supports displaced stepping on AArch64 GNU/Linux.
480 * "info threads", "info inferiors", "info display", "info checkpoints"
481 and "maint info program-spaces" now list the corresponding items in
482 ascending ID order, for consistency with all other "info" commands.
484 * In Ada, the overloads selection menu has been enhanced to display the
485 parameter types and the return types for the matching overloaded subprograms.
489 maint set target-non-stop (on|off|auto)
490 maint show target-non-stop
491 Control whether GDB targets always operate in non-stop mode even if
492 "set non-stop" is "off". The default is "auto", meaning non-stop
493 mode is enabled if supported by the target.
495 maint set bfd-sharing
496 maint show bfd-sharing
497 Control the reuse of bfd objects.
501 Control display of debugging info regarding bfd caching.
505 Control display of debugging info regarding FreeBSD threads.
507 set remote multiprocess-extensions-packet
508 show remote multiprocess-extensions-packet
509 Set/show the use of the remote protocol multiprocess extensions.
511 set remote thread-events
512 show remote thread-events
513 Set/show the use of thread create/exit events.
515 set ada print-signatures on|off
516 show ada print-signatures"
517 Control whether parameter types and return types are displayed in overloads
518 selection menus. It is activaled (@code{on}) by default.
522 Controls the maximum size of memory, in bytes, that GDB will
523 allocate for value contents. Prevents incorrect programs from
524 causing GDB to allocate overly large buffers. Default is 64k.
526 * The "disassemble" command accepts a new modifier: /s.
527 It prints mixed source+disassembly like /m with two differences:
528 - disassembled instructions are now printed in program order, and
529 - and source for all relevant files is now printed.
530 The "/m" option is now considered deprecated: its "source-centric"
531 output hasn't proved useful in practice.
533 * The "record instruction-history" command accepts a new modifier: /s.
534 It behaves exactly like /m and prints mixed source+disassembly.
536 * The "set scheduler-locking" command supports a new mode "replay".
537 It behaves like "off" in record mode and like "on" in replay mode.
539 * Support for various ROM monitors has been removed:
541 target dbug dBUG ROM monitor for Motorola ColdFire
542 target picobug Motorola picobug monitor
543 target dink32 DINK32 ROM monitor for PowerPC
544 target m32r Renesas M32R/D ROM monitor
545 target mon2000 mon2000 ROM monitor
546 target ppcbug PPCBUG ROM monitor for PowerPC
548 * Support for reading/writing memory and extracting values on architectures
549 whose memory is addressable in units of any integral multiple of 8 bits.
554 Indicates that an exec system call was executed.
556 exec-events feature in qSupported
557 The qSupported packet allows GDB to request support for exec
558 events using the new 'gdbfeature' exec-event, and the qSupported
559 response can contain the corresponding 'stubfeature'. Set and
560 show commands can be used to display whether these features are enabled.
563 Equivalent to interrupting with the ^C character, but works in
566 thread created stop reason (T05 create:...)
567 Indicates that the thread was just created and is stopped at entry.
569 thread exit stop reply (w exitcode;tid)
570 Indicates that the thread has terminated.
573 Enables/disables thread create and exit event reporting. For
574 example, this is used in non-stop mode when GDB stops a set of
575 threads and synchronously waits for the their corresponding stop
576 replies. Without exit events, if one of the threads exits, GDB
577 would hang forever not knowing that it should no longer expect a
578 stop for that same thread.
581 Indicates that there are no resumed threads left in the target (all
582 threads are stopped). The remote stub reports support for this stop
583 reply to GDB's qSupported query.
586 Enables/disables catching syscalls from the inferior process.
587 The remote stub reports support for this packet to GDB's qSupported query.
589 syscall_entry stop reason
590 Indicates that a syscall was just called.
592 syscall_return stop reason
593 Indicates that a syscall just returned.
595 * Extended-remote exec events
597 ** GDB now has support for exec events on extended-remote Linux targets.
598 For such targets with Linux kernels 2.5.46 and later, this enables
599 follow-exec-mode and exec catchpoints.
601 set remote exec-event-feature-packet
602 show remote exec-event-feature-packet
603 Set/show the use of the remote exec event feature.
605 * Thread names in remote protocol
607 The reply to qXfer:threads:read may now include a name attribute for each
610 * Target remote mode fork and exec events
612 ** GDB now has support for fork and exec events on target remote mode
613 Linux targets. For such targets with Linux kernels 2.5.46 and later,
614 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
615 fork and exec catchpoints.
617 * Remote syscall events
619 ** GDB now has support for catch syscall on remote Linux targets,
620 currently enabled on x86/x86_64 architectures.
622 set remote catch-syscall-packet
623 show remote catch-syscall-packet
624 Set/show the use of the remote catch syscall feature.
628 ** The -var-set-format command now accepts the zero-hexadecimal
629 format. It outputs data in hexadecimal format with zero-padding on the
634 ** gdb.InferiorThread objects have a new attribute "global_num",
635 which refers to the thread's global thread ID. The existing
636 "num" attribute now refers to the thread's per-inferior number.
637 See "Per-inferior thread numbers" above.
638 ** gdb.InferiorThread objects have a new attribute "inferior", which
639 is the Inferior object the thread belongs to.
641 *** Changes in GDB 7.10
643 * Support for process record-replay and reverse debugging on aarch64*-linux*
644 targets has been added. GDB now supports recording of A64 instruction set
645 including advance SIMD instructions.
647 * Support for Sun's version of the "stabs" debug file format has been removed.
649 * GDB now honors the content of the file /proc/PID/coredump_filter
650 (PID is the process ID) on GNU/Linux systems. This file can be used
651 to specify the types of memory mappings that will be included in a
652 corefile. For more information, please refer to the manual page of
653 "core(5)". GDB also has a new command: "set use-coredump-filter
654 on|off". It allows to set whether GDB will read the content of the
655 /proc/PID/coredump_filter file when generating a corefile.
657 * The "info os" command on GNU/Linux can now display information on
659 "info os cpus" Listing of all cpus/cores on the system
661 * GDB has two new commands: "set serial parity odd|even|none" and
662 "show serial parity". These allows to set or show parity for the
665 * The "info source" command now displays the producer string if it was
666 present in the debug info. This typically includes the compiler version
667 and may include things like its command line arguments.
669 * The "info dll", an alias of the "info sharedlibrary" command,
670 is now available on all platforms.
672 * Directory names supplied to the "set sysroot" commands may be
673 prefixed with "target:" to tell GDB to access shared libraries from
674 the target system, be it local or remote. This replaces the prefix
675 "remote:". The default sysroot has been changed from "" to
676 "target:". "remote:" is automatically converted to "target:" for
677 backward compatibility.
679 * The system root specified by "set sysroot" will be prepended to the
680 filename of the main executable (if reported to GDB as absolute by
681 the operating system) when starting processes remotely, and when
682 attaching to already-running local or remote processes.
684 * GDB now supports automatic location and retrieval of executable
685 files from remote targets. Remote debugging can now be initiated
686 using only a "target remote" or "target extended-remote" command
687 (no "set sysroot" or "file" commands are required). See "New remote
690 * The "dump" command now supports verilog hex format.
692 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
694 * On GNU/Linux, GDB and gdbserver are now able to access executable
695 and shared library files without a "set sysroot" command when
696 attaching to processes running in different mount namespaces from
697 the debugger. This makes it possible to attach to processes in
698 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
699 See "New remote packets" below.
701 * The "tui reg" command now provides completion for all of the
702 available register groups, including target specific groups.
704 * The HISTSIZE environment variable is no longer read when determining
705 the size of GDB's command history. GDB now instead reads the dedicated
706 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
707 disables truncation of command history. Non-numeric values of GDBHISTSIZE
712 ** Memory ports can now be unbuffered.
716 ** gdb.Objfile objects have a new attribute "username",
717 which is the name of the objfile as specified by the user,
718 without, for example, resolving symlinks.
719 ** You can now write frame unwinders in Python.
720 ** gdb.Type objects have a new method "optimized_out",
721 returning optimized out gdb.Value instance of this type.
722 ** gdb.Value objects have new methods "reference_value" and
723 "const_value" which return a reference to the value and a
724 "const" version of the value respectively.
728 maint print symbol-cache
729 Print the contents of the symbol cache.
731 maint print symbol-cache-statistics
732 Print statistics of symbol cache usage.
734 maint flush-symbol-cache
735 Flush the contents of the symbol cache.
739 Start branch trace recording using Branch Trace Store (BTS) format.
742 Evaluate expression by using the compiler and print result.
746 Explicit commands for enabling and disabling tui mode.
749 set mpx bound on i386 and amd64
750 Support for bound table investigation on Intel MPX enabled applications.
754 Start branch trace recording using Intel Processor Trace format.
757 Print information about branch tracing internals.
759 maint btrace packet-history
760 Print the raw branch tracing data.
762 maint btrace clear-packet-history
763 Discard the stored raw branch tracing data.
766 Discard all branch tracing data. It will be fetched and processed
767 anew by the next "record" command.
772 Renamed from "set debug dwarf2-die".
774 Renamed from "show debug dwarf2-die".
777 Renamed from "set debug dwarf2-read".
778 show debug dwarf-read
779 Renamed from "show debug dwarf2-read".
781 maint set dwarf always-disassemble
782 Renamed from "maint set dwarf2 always-disassemble".
783 maint show dwarf always-disassemble
784 Renamed from "maint show dwarf2 always-disassemble".
786 maint set dwarf max-cache-age
787 Renamed from "maint set dwarf2 max-cache-age".
788 maint show dwarf max-cache-age
789 Renamed from "maint show dwarf2 max-cache-age".
792 show debug dwarf-line
793 Control display of debugging info regarding DWARF line processing.
797 Set the maximum number of candidates to be considered during
798 completion. The default value is 200. This limit allows GDB
799 to avoid generating large completion lists, the computation of
800 which can cause the debugger to become temporarily unresponsive.
802 set history remove-duplicates
803 show history remove-duplicates
804 Control the removal of duplicate history entries.
806 maint set symbol-cache-size
807 maint show symbol-cache-size
808 Control the size of the symbol cache.
810 set|show record btrace bts buffer-size
811 Set and show the size of the ring buffer used for branch tracing in
813 The obtained size may differ from the requested size. Use "info
814 record" to see the obtained buffer size.
816 set debug linux-namespaces
817 show debug linux-namespaces
818 Control display of debugging info regarding Linux namespaces.
820 set|show record btrace pt buffer-size
821 Set and show the size of the ring buffer used for branch tracing in
822 Intel Processor Trace format.
823 The obtained size may differ from the requested size. Use "info
824 record" to see the obtained buffer size.
826 maint set|show btrace pt skip-pad
827 Set and show whether PAD packets are skipped when computing the
830 * The command 'thread apply all' can now support new option '-ascending'
831 to call its specified command for all threads in ascending order.
833 * Python/Guile scripting
835 ** GDB now supports auto-loading of Python/Guile scripts contained in the
836 special section named `.debug_gdb_scripts'.
840 qXfer:btrace-conf:read
841 Return the branch trace configuration for the current thread.
843 Qbtrace-conf:bts:size
844 Set the requested ring buffer size for branch tracing in BTS format.
847 Enable Intel Procesor Trace-based branch tracing for the current
848 process. The remote stub reports support for this packet to GDB's
852 Set the requested ring buffer size for branch tracing in Intel Processor
856 Indicates a memory breakpoint instruction was executed, irrespective
857 of whether it was GDB that planted the breakpoint or the breakpoint
858 is hardcoded in the program. This is required for correct non-stop
862 Indicates the target stopped for a hardware breakpoint. This is
863 required for correct non-stop mode operation.
866 Return information about files on the remote system.
869 Return the full absolute name of the file that was executed to
870 create a process running on the remote system.
873 Select the filesystem on which vFile: operations with filename
874 arguments will operate. This is required for GDB to be able to
875 access files on remote targets where the remote stub does not
876 share a common filesystem with the inferior(s).
879 Indicates that a fork system call was executed.
882 Indicates that a vfork system call was executed.
884 vforkdone stop reason
885 Indicates that a vfork child of the specified process has executed
886 an exec or exit, allowing the vfork parent to resume execution.
888 fork-events and vfork-events features in qSupported
889 The qSupported packet allows GDB to request support for fork and
890 vfork events using new 'gdbfeatures' fork-events and vfork-events,
891 and the qSupported response can contain the corresponding
892 'stubfeatures'. Set and show commands can be used to display
893 whether these features are enabled.
895 * Extended-remote fork events
897 ** GDB now has support for fork events on extended-remote Linux
898 targets. For targets with Linux kernels 2.5.60 and later, this
899 enables follow-fork-mode and detach-on-fork for both fork and
900 vfork, as well as fork and vfork catchpoints.
902 * The info record command now shows the recording format and the
903 branch tracing configuration for the current thread when using
904 the btrace record target.
905 For the BTS format, it shows the ring buffer size.
907 * GDB now has support for DTrace USDT (Userland Static Defined
908 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
910 * GDB now supports access to vector registers on S/390 GNU/Linux
913 * Removed command line options
915 -xdb HP-UX XDB compatibility mode.
917 * Removed targets and native configurations
919 HP/PA running HP-UX hppa*-*-hpux*
920 Itanium running HP-UX ia64-*-hpux*
922 * New configure options
925 This configure option allows the user to build GDB with support for
926 Intel Processor Trace (default: auto). This requires libipt.
928 --with-libipt-prefix=PATH
929 Specify the path to the version of libipt that GDB should use.
930 $PATH/include should contain the intel-pt.h header and
931 $PATH/lib should contain the libipt.so library.
933 *** Changes in GDB 7.9.1
937 ** Xmethods can now specify a result type.
939 *** Changes in GDB 7.9
941 * GDB now supports hardware watchpoints on x86 GNU Hurd.
945 ** You can now access frame registers from Python scripts.
946 ** New attribute 'producer' for gdb.Symtab objects.
947 ** gdb.Objfile objects have a new attribute "progspace",
948 which is the gdb.Progspace object of the containing program space.
949 ** gdb.Objfile objects have a new attribute "owner".
950 ** gdb.Objfile objects have a new attribute "build_id",
951 which is the build ID generated when the file was built.
952 ** gdb.Objfile objects have a new method "add_separate_debug_file".
953 ** A new event "gdb.clear_objfiles" has been added, triggered when
954 selecting a new file to debug.
955 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
956 ** New function gdb.lookup_objfile.
958 New events which are triggered when GDB modifies the state of the
961 ** gdb.events.inferior_call_pre: Function call is about to be made.
962 ** gdb.events.inferior_call_post: Function call has just been made.
963 ** gdb.events.memory_changed: A memory location has been altered.
964 ** gdb.events.register_changed: A register has been altered.
966 * New Python-based convenience functions:
968 ** $_caller_is(name [, number_of_frames])
969 ** $_caller_matches(regexp [, number_of_frames])
970 ** $_any_caller_is(name [, number_of_frames])
971 ** $_any_caller_matches(regexp [, number_of_frames])
973 * GDB now supports the compilation and injection of source code into
974 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
975 to compile the source code to object code, and if successful, inject
976 and execute that code within the current context of the inferior.
977 Currently the C language is supported. The commands used to
978 interface with this new feature are:
980 compile code [-raw|-r] [--] [source code]
981 compile file [-raw|-r] filename
985 demangle [-l language] [--] name
986 Demangle "name" in the specified language, or the current language
987 if elided. This command is renamed from the "maint demangle" command.
988 The latter is kept as a no-op to avoid "maint demangle" being interpreted
989 as "maint demangler-warning".
991 queue-signal signal-name-or-number
992 Queue a signal to be delivered to the thread when it is resumed.
994 add-auto-load-scripts-directory directory
995 Add entries to the list of directories from which to load auto-loaded
998 maint print user-registers
999 List all currently available "user" registers.
1001 compile code [-r|-raw] [--] [source code]
1002 Compile, inject, and execute in the inferior the executable object
1003 code produced by compiling the provided source code.
1005 compile file [-r|-raw] filename
1006 Compile and inject into the inferior the executable object code
1007 produced by compiling the source code stored in the filename
1010 * On resume, GDB now always passes the signal the program had stopped
1011 for to the thread the signal was sent to, even if the user changed
1012 threads before resuming. Previously GDB would often (but not
1013 always) deliver the signal to the thread that happens to be current
1016 * Conversely, the "signal" command now consistently delivers the
1017 requested signal to the current thread. GDB now asks for
1018 confirmation if the program had stopped for a signal and the user
1019 switched threads meanwhile.
1021 * "breakpoint always-inserted" modes "off" and "auto" merged.
1023 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1024 won't remove breakpoints from the target until all threads stop,
1025 even in non-stop mode. The "auto" mode has been removed, and "off"
1026 is now the default mode.
1030 set debug symbol-lookup
1031 show debug symbol-lookup
1032 Control display of debugging info regarding symbol lookup.
1036 ** The -list-thread-groups command outputs an exit-code field for
1037 inferiors that have exited.
1041 MIPS SDE mips*-sde*-elf*
1045 Support for these obsolete configurations has been removed.
1047 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1048 SGI Irix-5.x mips-*-irix5*
1049 SGI Irix-6.x mips-*-irix6*
1050 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1051 VAX running Ultrix vax-*-ultrix*
1053 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1054 and "assf"), have been removed. Use the "sharedlibrary" command, or
1055 its alias "share", instead.
1057 *** Changes in GDB 7.8
1059 * New command line options
1062 This is an alias for the --data-directory option.
1064 * GDB supports printing and modifying of variable length automatic arrays
1065 as specified in ISO C99.
1067 * The ARM simulator now supports instruction level tracing
1068 with or without disassembly.
1072 GDB now has support for scripting using Guile. Whether this is
1073 available is determined at configure time.
1074 Guile version 2.0 or greater is required.
1075 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1077 * New commands (for set/show, see "New options" below)
1081 Invoke CODE by passing it to the Guile interpreter.
1085 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1087 info auto-load guile-scripts [regexp]
1088 Print the list of automatically loaded Guile scripts.
1090 * The source command is now capable of sourcing Guile scripts.
1091 This feature is dependent on the debugger being built with Guile support.
1095 set print symbol-loading (off|brief|full)
1096 show print symbol-loading
1097 Control whether to print informational messages when loading symbol
1098 information for a file. The default is "full", but when debugging
1099 programs with large numbers of shared libraries the amount of output
1100 becomes less useful.
1102 set guile print-stack (none|message|full)
1103 show guile print-stack
1104 Show a stack trace when an error is encountered in a Guile script.
1106 set auto-load guile-scripts (on|off)
1107 show auto-load guile-scripts
1108 Control auto-loading of Guile script files.
1110 maint ada set ignore-descriptive-types (on|off)
1111 maint ada show ignore-descriptive-types
1112 Control whether the debugger should ignore descriptive types in Ada
1113 programs. The default is not to ignore the descriptive types. See
1114 the user manual for more details on descriptive types and the intended
1115 usage of this option.
1117 set auto-connect-native-target
1119 Control whether GDB is allowed to automatically connect to the
1120 native target for the run, attach, etc. commands when not connected
1121 to any target yet. See also "target native" below.
1123 set record btrace replay-memory-access (read-only|read-write)
1124 show record btrace replay-memory-access
1125 Control what memory accesses are allowed during replay.
1127 maint set target-async (on|off)
1128 maint show target-async
1129 This controls whether GDB targets operate in synchronous or
1130 asynchronous mode. Normally the default is asynchronous, if it is
1131 available; but this can be changed to more easily debug problems
1132 occurring only in synchronous mode.
1134 set mi-async (on|off)
1136 Control whether MI asynchronous mode is preferred. This supersedes
1137 "set target-async" of previous GDB versions.
1139 * "set target-async" is deprecated as a CLI option and is now an alias
1140 for "set mi-async" (only puts MI into async mode).
1142 * Background execution commands (e.g., "c&", "s&", etc.) are now
1143 possible ``out of the box'' if the target supports them. Previously
1144 the user would need to explicitly enable the possibility with the
1145 "set target-async on" command.
1147 * New features in the GDB remote stub, GDBserver
1149 ** New option --debug-format=option1[,option2,...] allows one to add
1150 additional text to each output. At present only timestamps
1151 are supported: --debug-format=timestamps.
1152 Timestamps can also be turned on with the
1153 "monitor set debug-format timestamps" command from GDB.
1155 * The 'record instruction-history' command now starts counting instructions
1156 at one. This also affects the instruction ranges reported by the
1157 'record function-call-history' command when given the /i modifier.
1159 * The command 'record function-call-history' supports a new modifier '/c' to
1160 indent the function names based on their call stack depth.
1161 The fields for the '/i' and '/l' modifier have been reordered.
1162 The source line range is now prefixed with 'at'.
1163 The instruction range is now prefixed with 'inst'.
1164 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1165 "record instruction-history" and "list" commands.
1167 * The ranges given as arguments to the 'record function-call-history' and
1168 'record instruction-history' commands are now inclusive.
1170 * The btrace record target now supports the 'record goto' command.
1171 For locations inside the execution trace, the back trace is computed
1172 based on the information stored in the execution trace.
1174 * The btrace record target supports limited reverse execution and replay.
1175 The target does not record data and therefore does not allow reading
1176 memory or registers.
1178 * The "catch syscall" command now works on s390*-linux* targets.
1180 * The "compare-sections" command is no longer specific to target
1181 remote. It now works with all targets.
1183 * All native targets are now consistently called "native".
1184 Consequently, the "target child", "target GNU", "target djgpp",
1185 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1186 commands have been replaced with "target native". The QNX/NTO port
1187 leaves the "procfs" target in place and adds a "native" target for
1188 consistency with other ports. The impact on users should be minimal
1189 as these commands previously either throwed an error, or were
1190 no-ops. The target's name is visible in the output of the following
1191 commands: "help target", "info target", "info files", "maint print
1194 * The "target native" command now connects to the native target. This
1195 can be used to launch native programs even when "set
1196 auto-connect-native-target" is set to off.
1198 * GDB now supports access to Intel MPX registers on GNU/Linux.
1200 * Support for Intel AVX-512 registers on GNU/Linux.
1201 Support displaying and modifying Intel AVX-512 registers
1202 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1204 * New remote packets
1206 qXfer:btrace:read's annex
1207 The qXfer:btrace:read packet supports a new annex 'delta' to read
1208 branch trace incrementally.
1212 ** Valid Python operations on gdb.Value objects representing
1213 structs/classes invoke the corresponding overloaded operators if
1215 ** New `Xmethods' feature in the Python API. Xmethods are
1216 additional methods or replacements for existing methods of a C++
1217 class. This feature is useful for those cases where a method
1218 defined in C++ source code could be inlined or optimized out by
1219 the compiler, making it unavailable to GDB.
1222 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1224 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1225 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1226 its alias "share", instead.
1228 * The commands "set remotebaud" and "show remotebaud" are no longer
1229 supported. Use "set serial baud" and "show serial baud" (respectively)
1234 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1235 target-async". The latter is left as a deprecated alias of the
1236 former for backward compatibility. If the target supports it,
1237 CLI background execution commands are now always possible by
1238 default, independently of whether the frontend stated a
1239 preference for asynchronous execution with "-gdb-set mi-async".
1240 Previously "-gdb-set target-async off" affected both MI execution
1241 commands and CLI execution commands.
1243 *** Changes in GDB 7.7
1245 * Improved support for process record-replay and reverse debugging on
1246 arm*-linux* targets. Support for thumb32 and syscall instruction
1247 recording has been added.
1249 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1251 * GDB now supports Fission DWP file format version 2.
1252 http://gcc.gnu.org/wiki/DebugFission
1254 * New convenience function "$_isvoid", to check whether an expression
1255 is void. A void expression is an expression where the type of the
1256 result is "void". For example, some convenience variables may be
1257 "void" when evaluated (e.g., "$_exitcode" before the execution of
1258 the program being debugged; or an undefined convenience variable).
1259 Another example, when calling a function whose return type is
1262 * The "maintenance print objfiles" command now takes an optional regexp.
1264 * The "catch syscall" command now works on arm*-linux* targets.
1266 * GDB now consistently shows "<not saved>" when printing values of
1267 registers the debug info indicates have not been saved in the frame
1268 and there's nowhere to retrieve them from
1269 (callee-saved/call-clobbered registers):
1274 (gdb) info registers rax
1277 Before, the former would print "<optimized out>", and the latter
1278 "*value not available*".
1280 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1285 ** Frame filters and frame decorators have been added.
1286 ** Temporary breakpoints are now supported.
1287 ** Line tables representation has been added.
1288 ** New attribute 'parent_type' for gdb.Field objects.
1289 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1290 ** New attribute 'name' for gdb.Type objects.
1294 Nios II ELF nios2*-*-elf
1295 Nios II GNU/Linux nios2*-*-linux
1296 Texas Instruments MSP430 msp430*-*-elf
1298 * Removed native configurations
1300 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1301 been removed. ELF variants of these configurations are kept supported.
1303 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1304 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1305 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1306 i[34567]86-*-openbsd3.[0-3]
1307 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1308 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1309 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1313 Like "catch throw", but catches a re-thrown exception.
1314 maint check-psymtabs
1315 Renamed from old "maint check-symtabs".
1317 Perform consistency checks on symtabs.
1318 maint expand-symtabs
1319 Expand symtabs matching an optional regexp.
1322 Display the details of GDB configure-time options.
1324 maint set|show per-command
1325 maint set|show per-command space
1326 maint set|show per-command time
1327 maint set|show per-command symtab
1328 Enable display of per-command gdb resource usage.
1330 remove-symbol-file FILENAME
1331 remove-symbol-file -a ADDRESS
1332 Remove a symbol file added via add-symbol-file. The file to remove
1333 can be identified by its filename or by an address that lies within
1334 the boundaries of this symbol file in memory.
1337 info exceptions REGEXP
1338 Display the list of Ada exceptions defined in the program being
1339 debugged. If provided, only the exceptions whose names match REGEXP
1344 set debug symfile off|on
1346 Control display of debugging info regarding reading symbol files and
1347 symbol tables within those files
1349 set print raw frame-arguments
1350 show print raw frame-arguments
1351 Set/show whether to print frame arguments in raw mode,
1352 disregarding any defined pretty-printers.
1354 set remote trace-status-packet
1355 show remote trace-status-packet
1356 Set/show the use of remote protocol qTStatus packet.
1360 Control display of debugging messages related to Nios II targets.
1364 Control whether target-assisted range stepping is enabled.
1366 set startup-with-shell
1367 show startup-with-shell
1368 Specifies whether Unix child processes are started via a shell or
1373 Use the target memory cache for accesses to the code segment. This
1374 improves performance of remote debugging (particularly disassembly).
1376 * You can now use a literal value 'unlimited' for options that
1377 interpret 0 or -1 as meaning "unlimited". E.g., "set
1378 trace-buffer-size unlimited" is now an alias for "set
1379 trace-buffer-size -1" and "set height unlimited" is now an alias for
1382 * The "set debug symtab-create" debugging option of GDB has been changed to
1383 accept a verbosity level. 0 means "off", 1 provides basic debugging
1384 output, and values of 2 or greater provides more verbose output.
1386 * New command-line options
1388 Display the details of GDB configure-time options.
1390 * The command 'tsave' can now support new option '-ctf' to save trace
1391 buffer in Common Trace Format.
1393 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1396 * GDB now implements the the C++ 'typeid' operator.
1398 * The new convenience variable $_exception holds the exception being
1399 thrown or caught at an exception-related catchpoint.
1401 * The exception-related catchpoints, like "catch throw", now accept a
1402 regular expression which can be used to filter exceptions by type.
1404 * The new convenience variable $_exitsignal is automatically set to
1405 the terminating signal number when the program being debugged dies
1406 due to an uncaught signal.
1410 ** All MI commands now accept an optional "--language" option.
1411 Support for this feature can be verified by using the "-list-features"
1412 command, which should contain "language-option".
1414 ** The new command -info-gdb-mi-command allows the user to determine
1415 whether a GDB/MI command is supported or not.
1417 ** The "^error" result record returned when trying to execute an undefined
1418 GDB/MI command now provides a variable named "code" whose content is the
1419 "undefined-command" error code. Support for this feature can be verified
1420 by using the "-list-features" command, which should contain
1421 "undefined-command-error-code".
1423 ** The -trace-save MI command can optionally save trace buffer in Common
1426 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1428 ** The command -data-list-register-values now accepts an optional
1429 "--skip-unavailable" option. When used, only the available registers
1432 ** The new command -trace-frame-collected dumps collected variables,
1433 computed expressions, tvars, memory and registers in a traceframe.
1435 ** The commands -stack-list-locals, -stack-list-arguments and
1436 -stack-list-variables now accept an option "--skip-unavailable".
1437 When used, only the available locals or arguments are displayed.
1439 ** The -exec-run command now accepts an optional "--start" option.
1440 When used, the command follows the same semantics as the "start"
1441 command, stopping the program's execution at the start of its
1442 main subprogram. Support for this feature can be verified using
1443 the "-list-features" command, which should contain
1444 "exec-run-start-option".
1446 ** The new commands -catch-assert and -catch-exceptions insert
1447 catchpoints stopping the program when Ada exceptions are raised.
1449 ** The new command -info-ada-exceptions provides the equivalent of
1450 the new "info exceptions" command.
1452 * New system-wide configuration scripts
1453 A GDB installation now provides scripts suitable for use as system-wide
1454 configuration scripts for the following systems:
1458 * GDB now supports target-assigned range stepping with remote targets.
1459 This improves the performance of stepping source lines by reducing
1460 the number of control packets from/to GDB. See "New remote packets"
1463 * GDB now understands the element 'tvar' in the XML traceframe info.
1464 It has the id of the collected trace state variables.
1466 * On S/390 targets that provide the transactional-execution feature,
1467 the program interruption transaction diagnostic block (TDB) is now
1468 represented as a number of additional "registers" in GDB.
1470 * New remote packets
1474 The vCont packet supports a new 'r' action, that tells the remote
1475 stub to step through an address range itself, without GDB
1476 involvemement at each single-step.
1478 qXfer:libraries-svr4:read's annex
1479 The previously unused annex of the qXfer:libraries-svr4:read packet
1480 is now used to support passing an argument list. The remote stub
1481 reports support for this argument list to GDB's qSupported query.
1482 The defined arguments are "start" and "prev", used to reduce work
1483 necessary for library list updating, resulting in significant
1486 * New features in the GDB remote stub, GDBserver
1488 ** GDBserver now supports target-assisted range stepping. Currently
1489 enabled on x86/x86_64 GNU/Linux targets.
1491 ** GDBserver now adds element 'tvar' in the XML in the reply to
1492 'qXfer:traceframe-info:read'. It has the id of the collected
1493 trace state variables.
1495 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1498 * New 'z' formatter for printing and examining memory, this displays the
1499 value as hexadecimal zero padded on the left to the size of the type.
1501 * GDB can now use Windows x64 unwinding data.
1503 * The "set remotebaud" command has been replaced by "set serial baud".
1504 Similarly, "show remotebaud" has been replaced by "show serial baud".
1505 The "set remotebaud" and "show remotebaud" commands are still available
1506 to provide backward compatibility with older versions of GDB.
1508 *** Changes in GDB 7.6
1510 * Target record has been renamed to record-full.
1511 Record/replay is now enabled with the "record full" command.
1512 This also affects settings that are associated with full record/replay
1513 that have been moved from "set/show record" to "set/show record full":
1515 set|show record full insn-number-max
1516 set|show record full stop-at-limit
1517 set|show record full memory-query
1519 * A new record target "record-btrace" has been added. The new target
1520 uses hardware support to record the control-flow of a process. It
1521 does not support replaying the execution, but it implements the
1522 below new commands for investigating the recorded execution log.
1523 This new recording method can be enabled using:
1527 The "record-btrace" target is only available on Intel Atom processors
1528 and requires a Linux kernel 2.6.32 or later.
1530 * Two new commands have been added for record/replay to give information
1531 about the recorded execution without having to replay the execution.
1532 The commands are only supported by "record btrace".
1534 record instruction-history prints the execution history at
1535 instruction granularity
1537 record function-call-history prints the execution history at
1538 function granularity
1540 * New native configurations
1542 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1543 FreeBSD/powerpc powerpc*-*-freebsd
1544 x86_64/Cygwin x86_64-*-cygwin*
1545 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1549 ARM AArch64 aarch64*-*-elf
1550 ARM AArch64 GNU/Linux aarch64*-*-linux
1551 Lynx 178 PowerPC powerpc-*-lynx*178
1552 x86_64/Cygwin x86_64-*-cygwin*
1553 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1555 * If the configured location of system.gdbinit file (as given by the
1556 --with-system-gdbinit option at configure time) is in the
1557 data-directory (as specified by --with-gdb-datadir at configure
1558 time) or in one of its subdirectories, then GDB will look for the
1559 system-wide init file in the directory specified by the
1560 --data-directory command-line option.
1562 * New command line options:
1564 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1565 other initialization files, unlike -nx which disables all of them.
1567 * Removed command line options
1569 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1572 * The 'ptype' and 'whatis' commands now accept an argument to control
1575 * 'info proc' now works on some core files.
1579 ** Vectors can be created with gdb.Type.vector.
1581 ** Python's atexit.register now works in GDB.
1583 ** Types can be pretty-printed via a Python API.
1585 ** Python 3 is now supported (in addition to Python 2.4 or later)
1587 ** New class gdb.Architecture exposes GDB's internal representation
1588 of architecture in the Python API.
1590 ** New method Frame.architecture returns the gdb.Architecture object
1591 corresponding to the frame's architecture.
1593 * New Python-based convenience functions:
1595 ** $_memeq(buf1, buf2, length)
1596 ** $_streq(str1, str2)
1598 ** $_regex(str, regex)
1600 * The 'cd' command now defaults to using '~' (the home directory) if not
1603 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1604 default for GCC since November 2000.
1606 * The command 'forward-search' can now be abbreviated as 'fo'.
1608 * The command 'info tracepoints' can now display 'installed on target'
1609 or 'not installed on target' for each non-pending location of tracepoint.
1611 * New configure options
1613 --enable-libmcheck/--disable-libmcheck
1614 By default, development versions are built with -lmcheck on hosts
1615 that support it, in order to help track memory corruption issues.
1616 Release versions, on the other hand, are built without -lmcheck
1617 by default. The --enable-libmcheck/--disable-libmcheck configure
1618 options allow the user to override that default.
1619 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1620 This configure option allows the user to build GDB with
1621 libbabeltrace using which GDB can read Common Trace Format data.
1623 * New commands (for set/show, see "New options" below)
1626 Catch signals. This is similar to "handle", but allows commands and
1627 conditions to be attached.
1630 List the BFDs known to GDB.
1632 python-interactive [command]
1634 Start a Python interactive prompt, or evaluate the optional command
1635 and print the result of expressions.
1638 "py" is a new alias for "python".
1640 enable type-printer [name]...
1641 disable type-printer [name]...
1642 Enable or disable type printers.
1646 ** For the Renesas Super-H architecture, the "regs" command has been removed
1647 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1652 set print type methods (on|off)
1653 show print type methods
1654 Control whether method declarations are displayed by "ptype".
1655 The default is to show them.
1657 set print type typedefs (on|off)
1658 show print type typedefs
1659 Control whether typedef definitions are displayed by "ptype".
1660 The default is to show them.
1662 set filename-display basename|relative|absolute
1663 show filename-display
1664 Control the way in which filenames is displayed.
1665 The default is "relative", which preserves previous behavior.
1667 set trace-buffer-size
1668 show trace-buffer-size
1669 Request target to change the size of trace buffer.
1671 set remote trace-buffer-size-packet auto|on|off
1672 show remote trace-buffer-size-packet
1673 Control the use of the remote protocol `QTBuffer:size' packet.
1677 Control display of debugging messages related to ARM AArch64.
1680 set debug coff-pe-read
1681 show debug coff-pe-read
1682 Control display of debugging messages related to reading of COFF/PE
1687 Control display of debugging messages related to Mach-O symbols
1690 set debug notification
1691 show debug notification
1692 Control display of debugging info for async remote notification.
1696 ** Command parameter changes are now notified using new async record
1697 "=cmd-param-changed".
1698 ** Trace frame changes caused by command "tfind" are now notified using
1699 new async record "=traceframe-changed".
1700 ** The creation, deletion and modification of trace state variables
1701 are now notified using new async records "=tsv-created",
1702 "=tsv-deleted" and "=tsv-modified".
1703 ** The start and stop of process record are now notified using new
1704 async record "=record-started" and "=record-stopped".
1705 ** Memory changes are now notified using new async record
1707 ** The data-disassemble command response will include a "fullname" field
1708 containing the absolute file name when source has been requested.
1709 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1710 command, to allow pattern filling of memory areas.
1711 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1712 library load/unload events.
1713 ** The response to breakpoint commands and breakpoint async records
1714 includes an "installed" field containing a boolean state about each
1715 non-pending tracepoint location is whether installed on target or not.
1716 ** Output of the "-trace-status" command includes a "trace-file" field
1717 containing the name of the trace file being examined. This field is
1718 optional, and only present when examining a trace file.
1719 ** The "fullname" field is now always present along with the "file" field,
1720 even if the file cannot be found by GDB.
1722 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1723 You must have the LZMA library available when configuring GDB for this
1724 feature to be enabled. For more information, see:
1725 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1727 * New remote packets
1730 Set the size of trace buffer. The remote stub reports support for this
1731 packet to gdb's qSupported query.
1734 Enable Branch Trace Store (BTS)-based branch tracing for the current
1735 thread. The remote stub reports support for this packet to gdb's
1739 Disable branch tracing for the current thread. The remote stub reports
1740 support for this packet to gdb's qSupported query.
1743 Read the traced branches for the current thread. The remote stub
1744 reports support for this packet to gdb's qSupported query.
1746 *** Changes in GDB 7.5
1748 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1749 for more x32 ABI info.
1751 * GDB now supports access to MIPS DSP registers on Linux targets.
1753 * GDB now supports debugging microMIPS binaries.
1755 * The "info os" command on GNU/Linux can now display information on
1756 several new classes of objects managed by the operating system:
1757 "info os procgroups" lists process groups
1758 "info os files" lists file descriptors
1759 "info os sockets" lists internet-domain sockets
1760 "info os shm" lists shared-memory regions
1761 "info os semaphores" lists semaphores
1762 "info os msg" lists message queues
1763 "info os modules" lists loaded kernel modules
1765 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1766 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1767 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1768 options and inspect the probe arguments using the new $_probe_arg family
1769 of convenience variables. You can obtain more information about SystemTap
1770 in <http://sourceware.org/systemtap/>.
1772 * GDB now supports reversible debugging on ARM, it allows you to
1773 debug basic ARM and THUMB instructions, and provides
1774 record/replay support.
1776 * The option "symbol-reloading" has been deleted as it is no longer used.
1780 ** GDB commands implemented in Python can now be put in command class
1783 ** The "maint set python print-stack on|off" is now deleted.
1785 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1786 apply "flag enum"-style pretty-printing to any enum.
1788 ** gdb.lookup_symbol can now work when there is no current frame.
1790 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1791 the source at which the symbol was defined.
1793 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1794 method 'value'. The former indicates whether the symbol needs a
1795 frame in order to compute its value, and the latter computes the
1798 ** A new method 'referenced_value' on gdb.Value objects which can
1799 dereference pointer as well as C++ reference values.
1801 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1802 which return the global and static blocks (as gdb.Block objects),
1803 of the underlying symbol table, respectively.
1805 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1806 object associated with a PC value.
1808 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1809 of the address range occupied by code for the current source line.
1811 * Go language support.
1812 GDB now supports debugging programs written in the Go programming
1815 * GDBserver now supports stdio connections.
1816 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1818 * The binary "gdbtui" can no longer be built or installed.
1819 Use "gdb -tui" instead.
1821 * GDB will now print "flag" enums specially. A flag enum is one where
1822 all the enumerator values have no bits in common when pairwise
1823 "and"ed. When printing a value whose type is a flag enum, GDB will
1824 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1825 (gdb) print (enum E) 3
1828 * The filename part of a linespec will now match trailing components
1829 of a source file name. For example, "break gcc/expr.c:1000" will
1830 now set a breakpoint in build/gcc/expr.c, but not
1831 build/libcpp/expr.c.
1833 * The "info proc" and "generate-core-file" commands will now also
1834 work on remote targets connected to GDBserver on Linux.
1836 * The command "info catch" has been removed. It has been disabled
1837 since December 2007.
1839 * The "catch exception" and "catch assert" commands now accept
1840 a condition at the end of the command, much like the "break"
1841 command does. For instance:
1843 (gdb) catch exception Constraint_Error if Barrier = True
1845 Previously, it was possible to add a condition to such catchpoints,
1846 but it had to be done as a second step, after the catchpoint had been
1847 created, using the "condition" command.
1849 * The "info static-tracepoint-marker" command will now also work on
1850 native Linux targets with in-process agent.
1852 * GDB can now set breakpoints on inlined functions.
1854 * The .gdb_index section has been updated to include symbols for
1855 inlined functions. GDB will ignore older .gdb_index sections by
1856 default, which could cause symbol files to be loaded more slowly
1857 until their .gdb_index sections can be recreated. The new command
1858 "set use-deprecated-index-sections on" will cause GDB to use any older
1859 .gdb_index sections it finds. This will restore performance, but the
1860 ability to set breakpoints on inlined functions will be lost in symbol
1861 files with older .gdb_index sections.
1863 The .gdb_index section has also been updated to record more information
1864 about each symbol. This speeds up the "info variables", "info functions"
1865 and "info types" commands when used with programs having the .gdb_index
1866 section, as well as speeding up debugging with shared libraries using
1867 the .gdb_index section.
1869 * Ada support for GDB/MI Variable Objects has been added.
1871 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1876 ** New command -info-os is the MI equivalent of "info os".
1878 ** Output logs ("set logging" and related) now include MI output.
1882 ** "set use-deprecated-index-sections on|off"
1883 "show use-deprecated-index-sections on|off"
1884 Controls the use of deprecated .gdb_index sections.
1886 ** "catch load" and "catch unload" can be used to stop when a shared
1887 library is loaded or unloaded, respectively.
1889 ** "enable count" can be used to auto-disable a breakpoint after
1892 ** "info vtbl" can be used to show the virtual method tables for
1893 C++ and Java objects.
1895 ** "explore" and its sub commands "explore value" and "explore type"
1896 can be used to recursively explore values and types of
1897 expressions. These commands are available only if GDB is
1898 configured with '--with-python'.
1900 ** "info auto-load" shows status of all kinds of auto-loaded files,
1901 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1902 sequences of commands files, "info auto-load python-scripts"
1903 shows status of auto-loading Python script files,
1904 "info auto-load local-gdbinit" shows status of loading init file
1905 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1906 status of inferior specific thread debugging shared library loading.
1908 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1909 and "show auto-load-scripts" commands have been deprecated, use their
1910 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1911 and "show auto-load python-scripts" counterparts instead.
1913 ** "dprintf location,format,args..." creates a dynamic printf, which
1914 is basically a breakpoint that does a printf and immediately
1915 resumes your program's execution, so it is like a printf that you
1916 can insert dynamically at runtime instead of at compiletime.
1918 ** "set print symbol"
1920 Controls whether GDB attempts to display the symbol, if any,
1921 corresponding to addresses it prints. This defaults to "on", but
1922 you can set it to "off" to restore GDB's previous behavior.
1924 * Deprecated commands
1926 ** For the Renesas Super-H architecture, the "regs" command has been
1927 deprecated, and "info all-registers" should be used instead.
1931 Renesas RL78 rl78-*-elf
1932 HP OpenVMS ia64 ia64-hp-openvms*
1934 * GDBserver supports evaluation of breakpoint conditions. When
1935 support is advertised by GDBserver, GDB may be told to send the
1936 breakpoint conditions in bytecode form to GDBserver. GDBserver
1937 will only report the breakpoint trigger to GDB when its condition
1942 set mips compression
1943 show mips compression
1944 Select the compressed ISA encoding used in functions that have no symbol
1945 information available. The encoding can be set to either of:
1948 and is updated automatically from ELF file flags if available.
1950 set breakpoint condition-evaluation
1951 show breakpoint condition-evaluation
1952 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1953 GDBserver ("target"). Default option "auto" chooses the most efficient
1955 This option can improve debugger efficiency depending on the speed of the
1959 Disable auto-loading globally.
1962 Show auto-loading setting of all kinds of auto-loaded files.
1964 set auto-load gdb-scripts on|off
1965 show auto-load gdb-scripts
1966 Control auto-loading of GDB canned sequences of commands files.
1968 set auto-load python-scripts on|off
1969 show auto-load python-scripts
1970 Control auto-loading of Python script files.
1972 set auto-load local-gdbinit on|off
1973 show auto-load local-gdbinit
1974 Control loading of init file (.gdbinit) from current directory.
1976 set auto-load libthread-db on|off
1977 show auto-load libthread-db
1978 Control auto-loading of inferior specific thread debugging shared library.
1980 set auto-load scripts-directory <dir1>[:<dir2>...]
1981 show auto-load scripts-directory
1982 Set a list of directories from which to load auto-loaded scripts.
1983 Automatically loaded Python scripts and GDB scripts are located in one
1984 of the directories listed by this option.
1985 The delimiter (':' above) may differ according to the host platform.
1987 set auto-load safe-path <dir1>[:<dir2>...]
1988 show auto-load safe-path
1989 Set a list of directories from which it is safe to auto-load files.
1990 The delimiter (':' above) may differ according to the host platform.
1992 set debug auto-load on|off
1993 show debug auto-load
1994 Control display of debugging info for auto-loading the files above.
1996 set dprintf-style gdb|call|agent
1998 Control the way in which a dynamic printf is performed; "gdb"
1999 requests a GDB printf command, while "call" causes dprintf to call a
2000 function in the inferior. "agent" requests that the target agent
2001 (such as GDBserver) do the printing.
2003 set dprintf-function <expr>
2004 show dprintf-function
2005 set dprintf-channel <expr>
2006 show dprintf-channel
2007 Set the function and optional first argument to the call when using
2008 the "call" style of dynamic printf.
2010 set disconnected-dprintf on|off
2011 show disconnected-dprintf
2012 Control whether agent-style dynamic printfs continue to be in effect
2013 after GDB disconnects.
2015 * New configure options
2017 --with-auto-load-dir
2018 Configure default value for the 'set auto-load scripts-directory'
2019 setting above. It defaults to '$debugdir:$datadir/auto-load',
2020 $debugdir representing global debugging info directories (available
2021 via 'show debug-file-directory') and $datadir representing GDB's data
2022 directory (available via 'show data-directory').
2024 --with-auto-load-safe-path
2025 Configure default value for the 'set auto-load safe-path' setting
2026 above. It defaults to the --with-auto-load-dir setting.
2028 --without-auto-load-safe-path
2029 Set 'set auto-load safe-path' to '/', effectively disabling this
2032 * New remote packets
2034 z0/z1 conditional breakpoints extension
2036 The z0/z1 breakpoint insertion packets have been extended to carry
2037 a list of conditional expressions over to the remote stub depending on the
2038 condition evaluation mode. The use of this extension can be controlled
2039 via the "set remote conditional-breakpoints-packet" command.
2043 Specify the signals which the remote stub may pass to the debugged
2044 program without GDB involvement.
2046 * New command line options
2048 --init-command=FILE, -ix Like --command, -x but execute it
2049 before loading inferior.
2050 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2051 execute it before loading inferior.
2053 *** Changes in GDB 7.4
2055 * GDB now handles ambiguous linespecs more consistently; the existing
2056 FILE:LINE support has been expanded to other types of linespecs. A
2057 breakpoint will now be set on all matching locations in all
2058 inferiors, and locations will be added or removed according to
2061 * GDB now allows you to skip uninteresting functions and files when
2062 stepping with the "skip function" and "skip file" commands.
2064 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2065 and "show remote hardware-watchpoint-length-limit". These allows to
2066 set or show the maximum length limit (in bytes) of a remote
2067 target hardware watchpoint.
2069 This allows e.g. to use "unlimited" hardware watchpoints with the
2070 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2071 watchpoints are slower than real hardware watchpoints but are
2072 significantly faster than gdb software watchpoints.
2076 ** The register_pretty_printer function in module gdb.printing now takes
2077 an optional `replace' argument. If True, the new printer replaces any
2080 ** The "maint set python print-stack on|off" command has been
2081 deprecated and will be deleted in GDB 7.5.
2082 A new command: "set python print-stack none|full|message" has
2083 replaced it. Additionally, the default for "print-stack" is
2084 now "message", which just prints the error message without
2087 ** A prompt substitution hook (prompt_hook) is now available to the
2090 ** A new Python module, gdb.prompt has been added to the GDB Python
2091 modules library. This module provides functionality for
2092 escape sequences in prompts (used by set/show
2093 extended-prompt). These escape sequences are replaced by their
2094 corresponding value.
2096 ** Python commands and convenience-functions located in
2097 'data-directory'/python/gdb/command and
2098 'data-directory'/python/gdb/function are now automatically loaded
2101 ** Blocks now provide four new attributes. global_block and
2102 static_block will return the global and static blocks
2103 respectively. is_static and is_global are boolean attributes
2104 that indicate if the block is one of those two types.
2106 ** Symbols now provide the "type" attribute, the type of the symbol.
2108 ** The "gdb.breakpoint" function has been deprecated in favor of
2111 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2112 of a function. This class is based on the "finish" command
2113 available in the CLI.
2115 ** Type objects for struct and union types now allow access to
2116 the fields using standard Python dictionary (mapping) methods.
2117 For example, "some_type['myfield']" now works, as does
2118 "some_type.items()".
2120 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2123 ** A new function, "deep_items" has been added to the gdb.types
2124 module in the GDB Python modules library. This function returns
2125 an iterator over the fields of a struct or union type. Unlike
2126 the standard Python "iteritems" method, it will recursively traverse
2127 any anonymous fields.
2131 ** "*stopped" events can report several new "reason"s, such as
2134 ** Breakpoint changes are now notified using new async records, like
2135 "=breakpoint-modified".
2137 ** New command -ada-task-info.
2139 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2140 $sdir specifies the default system locations of shared libraries.
2141 $pdir specifies the directory where the libpthread used by the application
2144 GDB no longer looks in $sdir and $pdir after it has searched the directories
2145 mentioned in libthread-db-search-path. If you want to search those
2146 directories, they must be specified in libthread-db-search-path.
2147 The default value of libthread-db-search-path on GNU/Linux and Solaris
2148 systems is now "$sdir:$pdir".
2150 $pdir is not supported by gdbserver, it is currently ignored.
2151 $sdir is supported by gdbserver.
2153 * New configure option --with-iconv-bin.
2154 When using the internationalization support like the one in the GNU C
2155 library, GDB will invoke the "iconv" program to get a list of supported
2156 character sets. If this program lives in a non-standard location, one can
2157 use this option to specify where to find it.
2159 * When natively debugging programs on PowerPC BookE processors running
2160 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2161 watchpoints, which specify a mask in addition to an address to watch.
2162 The mask specifies that some bits of an address (the bits which are
2163 reset in the mask) should be ignored when matching the address accessed
2164 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2165 section in the user manual for more details.
2167 * The new option --once causes GDBserver to stop listening for connections once
2168 the first connection is made. The listening port used by GDBserver will
2169 become available after that.
2171 * New commands "info macros" and "alias" have been added.
2173 * New function parameters suffix @entry specifies value of function parameter
2174 at the time the function got called. Entry values are available only since
2180 "!" is now an alias of the "shell" command.
2181 Note that no space is needed between "!" and SHELL COMMAND.
2185 watch EXPRESSION mask MASK_VALUE
2186 The watch command now supports the mask argument which allows creation
2187 of masked watchpoints, if the current architecture supports this feature.
2189 info auto-load-scripts [REGEXP]
2190 This command was formerly named "maintenance print section-scripts".
2191 It is now generally useful and is no longer a maintenance-only command.
2193 info macro [-all] [--] MACRO
2194 The info macro command has new options `-all' and `--'. The first for
2195 printing all definitions of a macro. The second for explicitly specifying
2196 the end of arguments and the beginning of the macro name in case the macro
2197 name starts with a hyphen.
2199 collect[/s] EXPRESSIONS
2200 The tracepoint collect command now takes an optional modifier "/s"
2201 that directs it to dereference pointer-to-character types and
2202 collect the bytes of memory up to a zero byte. The behavior is
2203 similar to what you see when you use the regular print command on a
2204 string. An optional integer following the "/s" sets a bound on the
2205 number of bytes that will be collected.
2208 The trace start command now interprets any supplied arguments as a
2209 note to be recorded with the trace run, with an effect similar to
2210 setting the variable trace-notes.
2213 The trace stop command now interprets any arguments as a note to be
2214 mentioned along with the tstatus report that the trace was stopped
2215 with a command. The effect is similar to setting the variable
2218 * Tracepoints can now be enabled and disabled at any time after a trace
2219 experiment has been started using the standard "enable" and "disable"
2220 commands. It is now possible to start a trace experiment with no enabled
2221 tracepoints; GDB will display a warning, but will allow the experiment to
2222 begin, assuming that tracepoints will be enabled as needed while the trace
2225 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2226 locations with 4-byte instructions, when they were previously
2227 limited to locations with instructions of 5 bytes or longer.
2231 set debug dwarf2-read
2232 show debug dwarf2-read
2233 Turns on or off display of debugging messages related to reading
2234 DWARF debug info. The default is off.
2236 set debug symtab-create
2237 show debug symtab-create
2238 Turns on or off display of debugging messages related to symbol table
2239 creation. The default is off.
2242 show extended-prompt
2243 Set the GDB prompt, and allow escape sequences to be inserted to
2244 display miscellaneous information (see 'help set extended-prompt'
2245 for the list of sequences). This prompt (and any information
2246 accessed through the escape sequences) is updated every time the
2247 prompt is displayed.
2249 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2250 show print entry-values
2251 Set printing of frame argument values at function entry. In some cases
2252 GDB can determine the value of function argument which was passed by the
2253 function caller, even if the value was modified inside the called function.
2255 set debug entry-values
2256 show debug entry-values
2257 Control display of debugging info for determining frame argument values at
2258 function entry and virtual tail call frames.
2260 set basenames-may-differ
2261 show basenames-may-differ
2262 Set whether a source file may have multiple base names.
2263 (A "base name" is the name of a file with the directory part removed.
2264 Example: The base name of "/home/user/hello.c" is "hello.c".)
2265 If set, GDB will canonicalize file names (e.g., expand symlinks)
2266 before comparing them. Canonicalization is an expensive operation,
2267 but it allows the same file be known by more than one base name.
2268 If not set (the default), all source files are assumed to have just
2269 one base name, and gdb will do file name comparisons more efficiently.
2275 Set a user name and notes for the current and any future trace runs.
2276 This is useful for long-running and/or disconnected traces, to
2277 inform others (or yourself) as to who is running the trace, supply
2278 contact information, or otherwise explain what is going on.
2280 set trace-stop-notes
2281 show trace-stop-notes
2282 Set a note attached to the trace run, that is displayed when the
2283 trace has been stopped by a tstop command. This is useful for
2284 instance as an explanation, if you are stopping a trace run that was
2285 started by someone else.
2287 * New remote packets
2291 Dynamically enable a tracepoint in a started trace experiment.
2295 Dynamically disable a tracepoint in a started trace experiment.
2299 Set the user and notes of the trace run.
2303 Query the current status of a tracepoint.
2307 Query the minimum length of instruction at which a fast tracepoint may
2310 * Dcache size (number of lines) and line-size are now runtime-configurable
2311 via "set dcache line" and "set dcache line-size" commands.
2315 Texas Instruments TMS320C6x tic6x-*-*
2319 Renesas RL78 rl78-*-elf
2321 *** Changes in GDB 7.3.1
2323 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2325 *** Changes in GDB 7.3
2327 * GDB has a new command: "thread find [REGEXP]".
2328 It finds the thread id whose name, target id, or thread extra info
2329 matches the given regular expression.
2331 * The "catch syscall" command now works on mips*-linux* targets.
2333 * The -data-disassemble MI command now supports modes 2 and 3 for
2334 dumping the instruction opcodes.
2336 * New command line options
2338 -data-directory DIR Specify DIR as the "data-directory".
2339 This is mostly for testing purposes.
2341 * The "maint set python auto-load on|off" command has been renamed to
2342 "set auto-load-scripts on|off".
2344 * GDB has a new command: "set directories".
2345 It is like the "dir" command except that it replaces the
2346 source path list instead of augmenting it.
2348 * GDB now understands thread names.
2350 On GNU/Linux, "info threads" will display the thread name as set by
2351 prctl or pthread_setname_np.
2353 There is also a new command, "thread name", which can be used to
2354 assign a name internally for GDB to display.
2357 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2358 has been integrated into GDB.
2362 ** The function gdb.Write now accepts an optional keyword 'stream'.
2363 This keyword, when provided, will direct the output to either
2364 stdout, stderr, or GDB's logging output.
2366 ** Parameters can now be be sub-classed in Python, and in particular
2367 you may implement the get_set_doc and get_show_doc functions.
2368 This improves how Parameter set/show documentation is processed
2369 and allows for more dynamic content.
2371 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2372 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2373 have an is_valid method.
2375 ** Breakpoints can now be sub-classed in Python, and in particular
2376 you may implement a 'stop' function that is executed each time
2377 the inferior reaches that breakpoint.
2379 ** New function gdb.lookup_global_symbol looks up a global symbol.
2381 ** GDB values in Python are now callable if the value represents a
2382 function. For example, if 'some_value' represents a function that
2383 takes two integer parameters and returns a value, you can call
2384 that function like so:
2386 result = some_value (10,20)
2388 ** Module gdb.types has been added.
2389 It contains a collection of utilities for working with gdb.Types objects:
2390 get_basic_type, has_field, make_enum_dict.
2392 ** Module gdb.printing has been added.
2393 It contains utilities for writing and registering pretty-printers.
2394 New classes: PrettyPrinter, SubPrettyPrinter,
2395 RegexpCollectionPrettyPrinter.
2396 New function: register_pretty_printer.
2398 ** New commands "info pretty-printers", "enable pretty-printer" and
2399 "disable pretty-printer" have been added.
2401 ** gdb.parameter("directories") is now available.
2403 ** New function gdb.newest_frame returns the newest frame in the
2406 ** The gdb.InferiorThread class has a new "name" attribute. This
2407 holds the thread's name.
2409 ** Python Support for Inferior events.
2410 Python scripts can add observers to be notified of events
2411 occurring in the process being debugged.
2412 The following events are currently supported:
2413 - gdb.events.cont Continue event.
2414 - gdb.events.exited Inferior exited event.
2415 - gdb.events.stop Signal received, and Breakpoint hit events.
2419 ** GDB now puts template parameters in scope when debugging in an
2420 instantiation. For example, if you have:
2422 template<int X> int func (void) { return X; }
2424 then if you step into func<5>, "print X" will show "5". This
2425 feature requires proper debuginfo support from the compiler; it
2426 was added to GCC 4.5.
2428 ** The motion commands "next", "finish", "until", and "advance" now
2429 work better when exceptions are thrown. In particular, GDB will
2430 no longer lose control of the inferior; instead, the GDB will
2431 stop the inferior at the point at which the exception is caught.
2432 This functionality requires a change in the exception handling
2433 code that was introduced in GCC 4.5.
2435 * GDB now follows GCC's rules on accessing volatile objects when
2436 reading or writing target state during expression evaluation.
2437 One notable difference to prior behavior is that "print x = 0"
2438 no longer generates a read of x; the value of the assignment is
2439 now always taken directly from the value being assigned.
2441 * GDB now has some support for using labels in the program's source in
2442 linespecs. For instance, you can use "advance label" to continue
2443 execution to a label.
2445 * GDB now has support for reading and writing a new .gdb_index
2446 section. This section holds a fast index of DWARF debugging
2447 information and can be used to greatly speed up GDB startup and
2448 operation. See the documentation for `save gdb-index' for details.
2450 * The "watch" command now accepts an optional "-location" argument.
2451 When used, this causes GDB to watch the memory referred to by the
2452 expression. Such a watchpoint is never deleted due to it going out
2455 * GDB now supports thread debugging of core dumps on GNU/Linux.
2457 GDB now activates thread debugging using the libthread_db library
2458 when debugging GNU/Linux core dumps, similarly to when debugging
2459 live processes. As a result, when debugging a core dump file, GDB
2460 is now able to display pthread_t ids of threads. For example, "info
2461 threads" shows the same output as when debugging the process when it
2462 was live. In earlier releases, you'd see something like this:
2465 * 1 LWP 6780 main () at main.c:10
2467 While now you see this:
2470 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2472 It is also now possible to inspect TLS variables when debugging core
2475 When debugging a core dump generated on a machine other than the one
2476 used to run GDB, you may need to point GDB at the correct
2477 libthread_db library with the "set libthread-db-search-path"
2478 command. See the user manual for more details on this command.
2480 * When natively debugging programs on PowerPC BookE processors running
2481 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2482 which stop execution of the inferior whenever it executes an instruction
2483 at any address within the specified range. See the "PowerPC Embedded"
2484 section in the user manual for more details.
2486 * New features in the GDB remote stub, GDBserver
2488 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2489 and i686 LynxOS (version 5.x).
2491 ** GDBserver is now supported on Blackfin Linux.
2493 * New native configurations
2495 ia64 HP-UX ia64-*-hpux*
2499 Analog Devices, Inc. Blackfin Processor bfin-*
2501 * Ada task switching is now supported on sparc-elf targets when
2502 debugging a program using the Ravenscar Profile. For more information,
2503 see the "Tasking Support when using the Ravenscar Profile" section
2504 in the GDB user manual.
2506 * Guile support was removed.
2508 * New features in the GNU simulator
2510 ** The --map-info flag lists all known core mappings.
2512 ** CFI flashes may be simulated via the "cfi" device.
2514 *** Changes in GDB 7.2
2516 * Shared library support for remote targets by default
2518 When GDB is configured for a generic, non-OS specific target, like
2519 for example, --target=arm-eabi or one of the many *-*-elf targets,
2520 GDB now queries remote stubs for loaded shared libraries using the
2521 `qXfer:libraries:read' packet. Previously, shared library support
2522 was always disabled for such configurations.
2526 ** Argument Dependent Lookup (ADL)
2528 In C++ ADL lookup directs function search to the namespaces of its
2529 arguments even if the namespace has not been imported.
2539 Here the compiler will search for `foo' in the namespace of 'b'
2540 and find A::foo. GDB now supports this. This construct is commonly
2541 used in the Standard Template Library for operators.
2543 ** Improved User Defined Operator Support
2545 In addition to member operators, GDB now supports lookup of operators
2546 defined in a namespace and imported with a `using' directive, operators
2547 defined in the global scope, operators imported implicitly from an
2548 anonymous namespace, and the ADL operators mentioned in the previous
2550 GDB now also supports proper overload resolution for all the previously
2551 mentioned flavors of operators.
2553 ** static const class members
2555 Printing of static const class members that are initialized in the
2556 class definition has been fixed.
2558 * Windows Thread Information Block access.
2560 On Windows targets, GDB now supports displaying the Windows Thread
2561 Information Block (TIB) structure. This structure is visible either
2562 by using the new command `info w32 thread-information-block' or, by
2563 dereferencing the new convenience variable named `$_tlb', a
2564 thread-specific pointer to the TIB. This feature is also supported
2565 when remote debugging using GDBserver.
2567 * Static tracepoints
2569 Static tracepoints are calls in the user program into a tracing
2570 library. One such library is a port of the LTTng kernel tracer to
2571 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2572 When debugging with GDBserver, GDB now supports combining the GDB
2573 tracepoint machinery with such libraries. For example: the user can
2574 use GDB to probe a static tracepoint marker (a call from the user
2575 program into the tracing library) with the new "strace" command (see
2576 "New commands" below). This creates a "static tracepoint" in the
2577 breakpoint list, that can be manipulated with the same feature set
2578 as fast and regular tracepoints. E.g., collect registers, local and
2579 global variables, collect trace state variables, and define
2580 tracepoint conditions. In addition, the user can collect extra
2581 static tracepoint marker specific data, by collecting the new
2582 $_sdata internal variable. When analyzing the trace buffer, you can
2583 inspect $_sdata like any other variable available to GDB. For more
2584 information, see the "Tracepoints" chapter in GDB user manual. New
2585 remote packets have been defined to support static tracepoints, see
2586 the "New remote packets" section below.
2588 * Better reconstruction of tracepoints after disconnected tracing
2590 GDB will attempt to download the original source form of tracepoint
2591 definitions when starting a trace run, and then will upload these
2592 upon reconnection to the target, resulting in a more accurate
2593 reconstruction of the tracepoints that are in use on the target.
2597 You can now exercise direct control over the ways that GDB can
2598 affect your program. For instance, you can disallow the setting of
2599 breakpoints, so that the program can run continuously (assuming
2600 non-stop mode). In addition, the "observer" variable is available
2601 to switch all of the different controls; in observer mode, GDB
2602 cannot affect the target's behavior at all, which is useful for
2603 tasks like diagnosing live systems in the field.
2605 * The new convenience variable $_thread holds the number of the
2608 * New remote packets
2612 Return the address of the Windows Thread Information Block of a given thread.
2616 In response to several of the tracepoint packets, the target may now
2617 also respond with a number of intermediate `qRelocInsn' request
2618 packets before the final result packet, to have GDB handle
2619 relocating an instruction to execute at a different address. This
2620 is particularly useful for stubs that support fast tracepoints. GDB
2621 reports support for this feature in the qSupported packet.
2625 List static tracepoint markers in the target program.
2629 List static tracepoint markers at a given address in the target
2632 qXfer:statictrace:read
2634 Read the static trace data collected (by a `collect $_sdata'
2635 tracepoint action). The remote stub reports support for this packet
2636 to gdb's qSupported query.
2640 Send the current settings of GDB's permission flags.
2644 Send part of the source (textual) form of a tracepoint definition,
2645 which includes location, conditional, and action list.
2647 * The source command now accepts a -s option to force searching for the
2648 script in the source search path even if the script name specifies
2651 * New features in the GDB remote stub, GDBserver
2653 - GDBserver now support tracepoints (including fast tracepoints, and
2654 static tracepoints). The feature is currently supported by the
2655 i386-linux and amd64-linux builds. See the "Tracepoints support
2656 in gdbserver" section in the manual for more information.
2658 GDBserver JIT compiles the tracepoint's conditional agent
2659 expression bytecode into native code whenever possible for low
2660 overhead dynamic tracepoints conditionals. For such tracepoints,
2661 an expression that examines program state is evaluated when the
2662 tracepoint is reached, in order to determine whether to capture
2663 trace data. If the condition is simple and false, processing the
2664 tracepoint finishes very quickly and no data is gathered.
2666 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2667 for static tracepoints support.
2669 - GDBserver now supports x86_64 Windows 64-bit debugging.
2671 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2672 it understands register description.
2674 * The --batch flag now disables pagination and queries.
2676 * X86 general purpose registers
2678 GDB now supports reading/writing byte, word and double-word x86
2679 general purpose registers directly. This means you can use, say,
2680 $ah or $ax to refer, respectively, to the byte register AH and
2681 16-bit word register AX that are actually portions of the 32-bit
2682 register EAX or 64-bit register RAX.
2684 * The `commands' command now accepts a range of breakpoints to modify.
2685 A plain `commands' following a command that creates multiple
2686 breakpoints affects all the breakpoints set by that command. This
2687 applies to breakpoints set by `rbreak', and also applies when a
2688 single `break' command creates multiple breakpoints (e.g.,
2689 breakpoints on overloaded c++ functions).
2691 * The `rbreak' command now accepts a filename specification as part of
2692 its argument, limiting the functions selected by the regex to those
2693 in the specified file.
2695 * Support for remote debugging Windows and SymbianOS shared libraries
2696 from Unix hosts has been improved. Non Windows GDB builds now can
2697 understand target reported file names that follow MS-DOS based file
2698 system semantics, such as file names that include drive letters and
2699 use the backslash character as directory separator. This makes it
2700 possible to transparently use the "set sysroot" and "set
2701 solib-search-path" on Unix hosts to point as host copies of the
2702 target's shared libraries. See the new command "set
2703 target-file-system-kind" described below, and the "Commands to
2704 specify files" section in the user manual for more information.
2708 eval template, expressions...
2709 Convert the values of one or more expressions under the control
2710 of the string template to a command line, and call it.
2712 set target-file-system-kind unix|dos-based|auto
2713 show target-file-system-kind
2714 Set or show the assumed file system kind for target reported file
2717 save breakpoints <filename>
2718 Save all current breakpoint definitions to a file suitable for use
2719 in a later debugging session. To read the saved breakpoint
2720 definitions, use the `source' command.
2722 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2725 info static-tracepoint-markers
2726 Display information about static tracepoint markers in the target.
2728 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2729 Define a static tracepoint by probing a marker at the given
2730 function, line, address, or marker ID.
2734 Enable and disable observer mode.
2736 set may-write-registers on|off
2737 set may-write-memory on|off
2738 set may-insert-breakpoints on|off
2739 set may-insert-tracepoints on|off
2740 set may-insert-fast-tracepoints on|off
2741 set may-interrupt on|off
2742 Set individual permissions for GDB effects on the target. Note that
2743 some of these settings can have undesirable or surprising
2744 consequences, particularly when changed in the middle of a session.
2745 For instance, disabling the writing of memory can prevent
2746 breakpoints from being inserted, cause single-stepping to fail, or
2747 even crash your program, if you disable after breakpoints have been
2748 inserted. However, GDB should not crash.
2750 set record memory-query on|off
2751 show record memory-query
2752 Control whether to stop the inferior if memory changes caused
2753 by an instruction cannot be recorded.
2758 The disassemble command now supports "start,+length" form of two arguments.
2762 ** GDB now provides a new directory location, called the python directory,
2763 where Python scripts written for GDB can be installed. The location
2764 of that directory is <data-directory>/python, where <data-directory>
2765 is the GDB data directory. For more details, see section `Scripting
2766 GDB using Python' in the manual.
2768 ** The GDB Python API now has access to breakpoints, symbols, symbol
2769 tables, program spaces, inferiors, threads and frame's code blocks.
2770 Additionally, GDB Parameters can now be created from the API, and
2771 manipulated via set/show in the CLI.
2773 ** New functions gdb.target_charset, gdb.target_wide_charset,
2774 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2776 ** New exception gdb.GdbError.
2778 ** Pretty-printers are now also looked up in the current program space.
2780 ** Pretty-printers can now be individually enabled and disabled.
2782 ** GDB now looks for names of Python scripts to auto-load in a
2783 special section named `.debug_gdb_scripts', in addition to looking
2784 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2786 * Tracepoint actions were unified with breakpoint commands. In particular,
2787 there are no longer differences in "info break" output for breakpoints and
2788 tracepoints and the "commands" command can be used for both tracepoints and
2789 regular breakpoints.
2793 ARM Symbian arm*-*-symbianelf*
2795 * D language support.
2796 GDB now supports debugging programs written in the D programming
2799 * GDB now supports the extended ptrace interface for PowerPC which is
2800 available since Linux kernel version 2.6.34. This automatically enables
2801 any hardware breakpoints and additional hardware watchpoints available in
2802 the processor. The old ptrace interface exposes just one hardware
2803 watchpoint and no hardware breakpoints.
2805 * GDB is now able to use the Data Value Compare (DVC) register available on
2806 embedded PowerPC processors to implement in hardware simple watchpoint
2807 conditions of the form:
2809 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2811 This works in native GDB running on Linux kernels with the extended ptrace
2812 interface mentioned above.
2814 *** Changes in GDB 7.1
2818 ** Namespace Support
2820 GDB now supports importing of namespaces in C++. This enables the
2821 user to inspect variables from imported namespaces. Support for
2822 namepace aliasing has also been added. So, if a namespace is
2823 aliased in the current scope (e.g. namepace C=A; ) the user can
2824 print variables using the alias (e.g. (gdb) print C::x).
2828 All known bugs relating to the printing of virtual base class were
2829 fixed. It is now possible to call overloaded static methods using a
2834 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2835 and reinterpret_cast<> are now handled by the C++ expression parser.
2839 Xilinx MicroBlaze microblaze-*-*
2844 Xilinx MicroBlaze microblaze
2847 * Multi-program debugging.
2849 GDB now has support for multi-program (a.k.a. multi-executable or
2850 multi-exec) debugging. This allows for debugging multiple inferiors
2851 simultaneously each running a different program under the same GDB
2852 session. See "Debugging Multiple Inferiors and Programs" in the
2853 manual for more information. This implied some user visible changes
2854 in the multi-inferior support. For example, "info inferiors" now
2855 lists inferiors that are not running yet or that have exited
2856 already. See also "New commands" and "New options" below.
2858 * New tracing features
2860 GDB's tracepoint facility now includes several new features:
2862 ** Trace state variables
2864 GDB tracepoints now include support for trace state variables, which
2865 are variables managed by the target agent during a tracing
2866 experiment. They are useful for tracepoints that trigger each
2867 other, so for instance one tracepoint can count hits in a variable,
2868 and then a second tracepoint has a condition that is true when the
2869 count reaches a particular value. Trace state variables share the
2870 $-syntax of GDB convenience variables, and can appear in both
2871 tracepoint actions and condition expressions. Use the "tvariable"
2872 command to create, and "info tvariables" to view; see "Trace State
2873 Variables" in the manual for more detail.
2877 GDB now includes an option for defining fast tracepoints, which
2878 targets may implement more efficiently, such as by installing a jump
2879 into the target agent rather than a trap instruction. The resulting
2880 speedup can be by two orders of magnitude or more, although the
2881 tradeoff is that some program locations on some target architectures
2882 might not allow fast tracepoint installation, for instance if the
2883 instruction to be replaced is shorter than the jump. To request a
2884 fast tracepoint, use the "ftrace" command, with syntax identical to
2885 the regular trace command.
2887 ** Disconnected tracing
2889 It is now possible to detach GDB from the target while it is running
2890 a trace experiment, then reconnect later to see how the experiment
2891 is going. In addition, a new variable disconnected-tracing lets you
2892 tell the target agent whether to continue running a trace if the
2893 connection is lost unexpectedly.
2897 GDB now has the ability to save the trace buffer into a file, and
2898 then use that file as a target, similarly to you can do with
2899 corefiles. You can select trace frames, print data that was
2900 collected in them, and use tstatus to display the state of the
2901 tracing run at the moment that it was saved. To create a trace
2902 file, use "tsave <filename>", and to use it, do "target tfile
2905 ** Circular trace buffer
2907 You can ask the target agent to handle the trace buffer as a
2908 circular buffer, discarding the oldest trace frames to make room for
2909 newer ones, by setting circular-trace-buffer to on. This feature may
2910 not be available for all target agents.
2915 The disassemble command, when invoked with two arguments, now requires
2916 the arguments to be comma-separated.
2919 The info variables command now displays variable definitions. Files
2920 which only declare a variable are not shown.
2923 The source command is now capable of sourcing Python scripts.
2924 This feature is dependent on the debugger being build with Python
2927 Related to this enhancement is also the introduction of a new command
2928 "set script-extension" (see below).
2930 * New commands (for set/show, see "New options" below)
2932 record save [<FILENAME>]
2933 Save a file (in core file format) containing the process record
2934 execution log for replay debugging at a later time.
2936 record restore <FILENAME>
2937 Restore the process record execution log that was saved at an
2938 earlier time, for replay debugging.
2940 add-inferior [-copies <N>] [-exec <FILENAME>]
2943 clone-inferior [-copies <N>] [ID]
2944 Make a new inferior ready to execute the same program another
2945 inferior has loaded.
2950 maint info program-spaces
2951 List the program spaces loaded into GDB.
2953 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2954 show remote interrupt-sequence
2955 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2956 as the sequence to the remote target in order to interrupt the execution.
2957 Ctrl-C is a default. Some system prefers BREAK which is high level of
2958 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2959 Magic SysRq g. It is BREAK signal and character 'g'.
2961 set remote interrupt-on-connect [on | off]
2962 show remote interrupt-on-connect
2963 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2964 remote target when gdb connects to it. This is needed when you debug
2967 set remotebreak [on | off]
2969 Deprecated. Use "set/show remote interrupt-sequence" instead.
2971 tvariable $NAME [ = EXP ]
2972 Create or modify a trace state variable.
2975 List trace state variables and their values.
2977 delete tvariable $NAME ...
2978 Delete one or more trace state variables.
2981 Evaluate the given expressions without collecting anything into the
2982 trace buffer. (Valid in tracepoint actions only.)
2984 ftrace FN / FILE:LINE / *ADDR
2985 Define a fast tracepoint at the given function, line, or address.
2987 * New expression syntax
2989 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2990 GDB now parses 0b101010 identically with 42.
2994 set follow-exec-mode new|same
2995 show follow-exec-mode
2996 Control whether GDB reuses the same inferior across an exec call or
2997 creates a new one. This is useful to be able to restart the old
2998 executable after the inferior having done an exec call.
3000 set default-collect EXPR, ...
3001 show default-collect
3002 Define a list of expressions to be collected at each tracepoint.
3003 This is a useful way to ensure essential items are not overlooked,
3004 such as registers or a critical global variable.
3006 set disconnected-tracing
3007 show disconnected-tracing
3008 If set to 1, the target is instructed to continue tracing if it
3009 loses its connection to GDB. If 0, the target is to stop tracing
3012 set circular-trace-buffer
3013 show circular-trace-buffer
3014 If set to on, the target is instructed to use a circular trace buffer
3015 and discard the oldest trace frames instead of stopping the trace due
3016 to a full trace buffer. If set to off, the trace stops when the buffer
3017 fills up. Some targets may not support this.
3019 set script-extension off|soft|strict
3020 show script-extension
3021 If set to "off", the debugger does not perform any script language
3022 recognition, and all sourced files are assumed to be GDB scripts.
3023 If set to "soft" (the default), files are sourced according to
3024 filename extension, falling back to GDB scripts if the first
3026 If set to "strict", files are sourced according to filename extension.
3028 set ada trust-PAD-over-XVS on|off
3029 show ada trust-PAD-over-XVS
3030 If off, activate a workaround against a bug in the debugging information
3031 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3032 the GCC sources for more information about the GNAT encoding and
3033 PAD types in particular). It is always safe to set this option to
3034 off, but this introduces a slight performance penalty. The default
3037 * Python API Improvements
3039 ** GDB provides the new class gdb.LazyString. This is useful in
3040 some pretty-printing cases. The new method gdb.Value.lazy_string
3041 provides a simple way to create objects of this type.
3043 ** The fields returned by gdb.Type.fields now have an
3044 `is_base_class' attribute.
3046 ** The new method gdb.Type.range returns the range of an array type.
3048 ** The new method gdb.parse_and_eval can be used to parse and
3049 evaluate an expression.
3051 * New remote packets
3054 Define a trace state variable.
3057 Get the current value of a trace state variable.
3060 Set desired tracing behavior upon disconnection.
3063 Set the trace buffer to be linear or circular.
3066 Get data about the tracepoints currently in use.
3070 Process record now works correctly with hardware watchpoints.
3072 Multiple bug fixes have been made to the mips-irix port, making it
3073 much more reliable. In particular:
3074 - Debugging threaded applications is now possible again. Previously,
3075 GDB would hang while starting the program, or while waiting for
3076 the program to stop at a breakpoint.
3077 - Attaching to a running process no longer hangs.
3078 - An error occurring while loading a core file has been fixed.
3079 - Changing the value of the PC register now works again. This fixes
3080 problems observed when using the "jump" command, or when calling
3081 a function from GDB, or even when assigning a new value to $pc.
3082 - With the "finish" and "return" commands, the return value for functions
3083 returning a small array is now correctly printed.
3084 - It is now possible to break on shared library code which gets executed
3085 during a shared library init phase (code executed while executing
3086 their .init section). Previously, the breakpoint would have no effect.
3087 - GDB is now able to backtrace through the signal handler for
3088 non-threaded programs.
3090 PIE (Position Independent Executable) programs debugging is now supported.
3091 This includes debugging execution of PIC (Position Independent Code) shared
3092 libraries although for that, it should be possible to run such libraries as an
3095 *** Changes in GDB 7.0
3097 * GDB now has an interface for JIT compilation. Applications that
3098 dynamically generate code can create symbol files in memory and register
3099 them with GDB. For users, the feature should work transparently, and
3100 for JIT developers, the interface is documented in the GDB manual in the
3101 "JIT Compilation Interface" chapter.
3103 * Tracepoints may now be conditional. The syntax is as for
3104 breakpoints; either an "if" clause appended to the "trace" command,
3105 or the "condition" command is available. GDB sends the condition to
3106 the target for evaluation using the same bytecode format as is used
3107 for tracepoint actions.
3109 * The disassemble command now supports: an optional /r modifier, print the
3110 raw instructions in hex as well as in symbolic form, and an optional /m
3111 modifier to print mixed source+assembly.
3113 * Process record and replay
3115 In a architecture environment that supports ``process record and
3116 replay'', ``process record and replay'' target can record a log of
3117 the process execution, and replay it with both forward and reverse
3120 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3121 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3122 set execution-direction {forward|reverse}, for targets that support
3125 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3126 feature is available with a native GDB running on kernel version
3129 * GDB now has support for multi-byte and wide character sets on the
3130 target. Strings whose character type is wchar_t, char16_t, or
3131 char32_t are now correctly printed. GDB supports wide- and unicode-
3132 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3133 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3134 `printf'. This feature requires iconv to work properly; if your
3135 system does not have a working iconv, GDB can use GNU libiconv. See
3136 the installation instructions for more information.
3138 * GDB now supports automatic retrieval of shared library files from
3139 remote targets. To use this feature, specify a system root that begins
3140 with the `remote:' prefix, either via the `set sysroot' command or via
3141 the `--with-sysroot' configure-time option.
3143 * "info sharedlibrary" now takes an optional regex of libraries to show,
3144 and it now reports if a shared library has no debugging information.
3146 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3147 now complete on file names.
3149 * When completing in expressions, gdb will attempt to limit
3150 completions to allowable structure or union fields, where appropriate.
3151 For instance, consider:
3153 # struct example { int f1; double f2; };
3154 # struct example variable;
3157 If the user types TAB at the end of this command line, the available
3158 completions will be "f1" and "f2".
3160 * Inlined functions are now supported. They show up in backtraces, and
3161 the "step", "next", and "finish" commands handle them automatically.
3163 * GDB now supports the token-splicing (##) and stringification (#)
3164 operators when expanding macros. It also supports variable-arity
3167 * GDB now supports inspecting extra signal information, exported by
3168 the new $_siginfo convenience variable. The feature is currently
3169 implemented on linux ARM, i386 and amd64.
3171 * GDB can now display the VFP floating point registers and NEON vector
3172 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3173 can provide these registers (requires Linux 2.6.30 or later). Remote
3174 and simulator targets may also provide them.
3176 * New remote packets
3179 Search memory for a sequence of bytes.
3182 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3183 operation over reliable transport links. Use of this packet is
3184 controlled by the `set remote noack-packet' command.
3187 Kill the process with the specified process ID. Use this in preference
3188 to `k' when multiprocess protocol extensions are supported.
3191 Obtains additional operating system information
3195 Read or write additional signal information.
3197 * Removed remote protocol undocumented extension
3199 An undocumented extension to the remote protocol's `S' stop reply
3200 packet that permited the stub to pass a process id was removed.
3201 Remote servers should use the `T' stop reply packet instead.
3203 * GDB now supports multiple function calling conventions according to the
3204 DWARF-2 DW_AT_calling_convention function attribute.
3206 * The SH target utilizes the aforementioned change to distinguish between gcc
3207 and Renesas calling convention. It also adds the new CLI commands
3208 `set/show sh calling-convention'.
3210 * GDB can now read compressed debug sections, as produced by GNU gold
3211 with the --compress-debug-sections=zlib flag.
3213 * 64-bit core files are now supported on AIX.
3215 * Thread switching is now supported on Tru64.
3217 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3218 which will be allocated using malloc later in program execution.
3220 * The qXfer:libraries:read remote procotol packet now allows passing a
3221 list of section offsets.
3223 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3224 conditions handling signals delivered during attach or thread creation
3225 have also been fixed.
3227 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3228 From the user's standpoint, all unqualified instances of True and False
3229 are treated as the standard definitions, regardless of context.
3231 * GDB now parses C++ symbol and type names more flexibly. For
3234 template<typename T> class C { };
3237 GDB will now correctly handle all of:
3239 ptype C<char const *>
3240 ptype C<char const*>
3241 ptype C<const char *>
3242 ptype C<const char*>
3244 * New features in the GDB remote stub, gdbserver
3246 - The "--wrapper" command-line argument tells gdbserver to use a
3247 wrapper program to launch programs for debugging.
3249 - On PowerPC and S/390 targets, it is now possible to use a single
3250 gdbserver executable to debug both 32-bit and 64-bit programs.
3251 (This requires gdbserver itself to be built as a 64-bit executable.)
3253 - gdbserver uses the new noack protocol mode for TCP connections to
3254 reduce communications latency, if also supported and enabled in GDB.
3256 - Support for the sparc64-linux-gnu target is now included in
3259 - The amd64-linux build of gdbserver now supports debugging both
3260 32-bit and 64-bit programs.
3262 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3263 now support hardware watchpoints, and will use them automatically
3268 GDB now has support for scripting using Python. Whether this is
3269 available is determined at configure time.
3271 New GDB commands can now be written in Python.
3273 * Ada tasking support
3275 Ada tasks can now be inspected in GDB. The following commands have
3279 Print the list of Ada tasks.
3281 Print detailed information about task number N.
3283 Print the task number of the current task.
3285 Switch the context of debugging to task number N.
3287 * Support for user-defined prefixed commands. The "define" command can
3288 add new commands to existing prefixes, e.g. "target".
3290 * Multi-inferior, multi-process debugging.
3292 GDB now has generalized support for multi-inferior debugging. See
3293 "Debugging Multiple Inferiors" in the manual for more information.
3294 Although availability still depends on target support, the command
3295 set is more uniform now. The GNU/Linux specific multi-forks support
3296 has been migrated to this new framework. This implied some user
3297 visible changes; see "New commands" and also "Removed commands"
3300 * Target descriptions can now describe the target OS ABI. See the
3301 "Target Description Format" section in the user manual for more
3304 * Target descriptions can now describe "compatible" architectures
3305 to indicate that the target can execute applications for a different
3306 architecture in addition to those for the main target architecture.
3307 See the "Target Description Format" section in the user manual for
3310 * Multi-architecture debugging.
3312 GDB now includes general supports for debugging applications on
3313 hybrid systems that use more than one single processor architecture
3314 at the same time. Each such hybrid architecture still requires
3315 specific support to be added. The only hybrid architecture supported
3316 in this version of GDB is the Cell Broadband Engine.
3318 * GDB now supports integrated debugging of Cell/B.E. applications that
3319 use both the PPU and SPU architectures. To enable support for hybrid
3320 Cell/B.E. debugging, you need to configure GDB to support both the
3321 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3322 --enable-targets configure option.
3324 * Non-stop mode debugging.
3326 For some targets, GDB now supports an optional mode of operation in
3327 which you can examine stopped threads while other threads continue
3328 to execute freely. This is referred to as non-stop mode, with the
3329 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3330 section in the user manual for more information.
3332 To be able to support remote non-stop debugging, a remote stub needs
3333 to implement the non-stop mode remote protocol extensions, as
3334 described in the "Remote Non-Stop" section of the user manual. The
3335 GDB remote stub, gdbserver, has been adjusted to support these
3336 extensions on linux targets.
3338 * New commands (for set/show, see "New options" below)
3340 catch syscall [NAME(S) | NUMBER(S)]
3341 Catch system calls. Arguments, which should be names of system
3342 calls or their numbers, mean catch only those syscalls. Without
3343 arguments, every syscall will be caught. When the inferior issues
3344 any of the specified syscalls, GDB will stop and announce the system
3345 call, both when it is called and when its call returns. This
3346 feature is currently available with a native GDB running on the
3347 Linux Kernel, under the following architectures: x86, x86_64,
3348 PowerPC and PowerPC64.
3350 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3352 Search memory for a sequence of bytes.
3354 maint set python print-stack
3355 maint show python print-stack
3356 Show a stack trace when an error is encountered in a Python script.
3359 Invoke CODE by passing it to the Python interpreter.
3364 These allow macros to be defined, undefined, and listed
3368 Show operating system information about processes.
3371 List the inferiors currently under GDB's control.
3374 Switch focus to inferior number NUM.
3377 Detach from inferior number NUM.
3380 Kill inferior number NUM.
3384 set spu stop-on-load
3385 show spu stop-on-load
3386 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3388 set spu auto-flush-cache
3389 show spu auto-flush-cache
3390 Control whether to automatically flush the software-managed cache
3391 during Cell/B.E. debugging.
3393 set sh calling-convention
3394 show sh calling-convention
3395 Control the calling convention used when calling SH target functions.
3398 show debug timestamp
3399 Control display of timestamps with GDB debugging output.
3401 set disassemble-next-line
3402 show disassemble-next-line
3403 Control display of disassembled source lines or instructions when
3406 set remote noack-packet
3407 show remote noack-packet
3408 Set/show the use of remote protocol QStartNoAckMode packet. See above
3409 under "New remote packets."
3411 set remote query-attached-packet
3412 show remote query-attached-packet
3413 Control use of remote protocol `qAttached' (query-attached) packet.
3415 set remote read-siginfo-object
3416 show remote read-siginfo-object
3417 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3420 set remote write-siginfo-object
3421 show remote write-siginfo-object
3422 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3425 set remote reverse-continue
3426 show remote reverse-continue
3427 Control use of remote protocol 'bc' (reverse-continue) packet.
3429 set remote reverse-step
3430 show remote reverse-step
3431 Control use of remote protocol 'bs' (reverse-step) packet.
3433 set displaced-stepping
3434 show displaced-stepping
3435 Control displaced stepping mode. Displaced stepping is a way to
3436 single-step over breakpoints without removing them from the debuggee.
3437 Also known as "out-of-line single-stepping".
3440 show debug displaced
3441 Control display of debugging info for displaced stepping.
3443 maint set internal-error
3444 maint show internal-error
3445 Control what GDB does when an internal error is detected.
3447 maint set internal-warning
3448 maint show internal-warning
3449 Control what GDB does when an internal warning is detected.
3454 Use a wrapper program to launch programs for debugging.
3456 set multiple-symbols (all|ask|cancel)
3457 show multiple-symbols
3458 The value of this variable can be changed to adjust the debugger behavior
3459 when an expression or a breakpoint location contains an ambiguous symbol
3460 name (an overloaded function name, for instance).
3462 set breakpoint always-inserted
3463 show breakpoint always-inserted
3464 Keep breakpoints always inserted in the target, as opposed to inserting
3465 them when resuming the target, and removing them when the target stops.
3466 This option can improve debugger performance on slow remote targets.
3468 set arm fallback-mode (arm|thumb|auto)
3469 show arm fallback-mode
3470 set arm force-mode (arm|thumb|auto)
3472 These commands control how ARM GDB determines whether instructions
3473 are ARM or Thumb. The default for both settings is auto, which uses
3474 the current CPSR value for instructions without symbols; previous
3475 versions of GDB behaved as if "set arm fallback-mode arm".
3477 set disable-randomization
3478 show disable-randomization
3479 Standalone programs run with the virtual address space randomization enabled
3480 by default on some platforms. This option keeps the addresses stable across
3481 multiple debugging sessions.
3485 Control whether other threads are stopped or not when some thread hits
3490 Requests that asynchronous execution is enabled in the target, if available.
3491 In this case, it's possible to resume target in the background, and interact
3492 with GDB while the target is running. "show target-async" displays the
3493 current state of asynchronous execution of the target.
3495 set target-wide-charset
3496 show target-wide-charset
3497 The target-wide-charset is the name of the character set that GDB
3498 uses when printing characters whose type is wchar_t.
3500 set tcp auto-retry (on|off)
3502 set tcp connect-timeout
3503 show tcp connect-timeout
3504 These commands allow GDB to retry failed TCP connections to a remote stub
3505 with a specified timeout period; this is useful if the stub is launched
3506 in parallel with GDB but may not be ready to accept connections immediately.
3508 set libthread-db-search-path
3509 show libthread-db-search-path
3510 Control list of directories which GDB will search for appropriate
3513 set schedule-multiple (on|off)
3514 show schedule-multiple
3515 Allow GDB to resume all threads of all processes or only threads of
3516 the current process.
3520 Use more aggressive caching for accesses to the stack. This improves
3521 performance of remote debugging (particularly backtraces) without
3522 affecting correctness.
3524 set interactive-mode (on|off|auto)
3525 show interactive-mode
3526 Control whether GDB runs in interactive mode (on) or not (off).
3527 When in interactive mode, GDB waits for the user to answer all
3528 queries. Otherwise, GDB does not wait and assumes the default
3529 answer. When set to auto (the default), GDB determines which
3530 mode to use based on the stdin settings.
3535 For program forks, this is replaced by the new more generic `info
3536 inferiors' command. To list checkpoints, you can still use the
3537 `info checkpoints' command, which was an alias for the `info forks'
3541 Replaced by the new `inferior' command. To switch between
3542 checkpoints, you can still use the `restart' command, which was an
3543 alias for the `fork' command.
3546 This is removed, since some targets don't have a notion of
3547 processes. To switch between processes, you can still use the
3548 `inferior' command using GDB's own inferior number.
3551 For program forks, this is replaced by the new more generic `kill
3552 inferior' command. To delete a checkpoint, you can still use the
3553 `delete checkpoint' command, which was an alias for the `delete
3557 For program forks, this is replaced by the new more generic `detach
3558 inferior' command. To detach a checkpoint, you can still use the
3559 `detach checkpoint' command, which was an alias for the `detach
3562 * New native configurations
3564 x86/x86_64 Darwin i[34567]86-*-darwin*
3566 x86_64 MinGW x86_64-*-mingw*
3570 Lattice Mico32 lm32-*
3571 x86 DICOS i[34567]86-*-dicos*
3572 x86_64 DICOS x86_64-*-dicos*
3575 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3576 (mingw32ce) debugging.
3582 These commands were actually not implemented on any target.
3584 *** Changes in GDB 6.8
3586 * New native configurations
3588 NetBSD/hppa hppa*-*netbsd*
3589 Xtensa GNU/Linux xtensa*-*-linux*
3593 NetBSD/hppa hppa*-*-netbsd*
3594 Xtensa GNU/Lunux xtensa*-*-linux*
3596 * Change in command line behavior -- corefiles vs. process ids.
3598 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3599 attaching to process NUMBER fails, GDB no longer attempts to open a
3600 core file named NUMBER. Attaching to a program using the -c option
3601 is no longer supported. Instead, use the '-p' or '--pid' options.
3603 * GDB can now be built as a native debugger for debugging Windows x86
3604 (mingw32) Portable Executable (PE) programs.
3606 * Pending breakpoints no longer change their number when their address
3609 * GDB now supports breakpoints with multiple locations,
3610 including breakpoints on C++ constructors, inside C++ templates,
3611 and in inlined functions.
3613 * GDB's ability to debug optimized code has been improved. GDB more
3614 accurately identifies function bodies and lexical blocks that occupy
3615 more than one contiguous range of addresses.
3617 * Target descriptions can now describe registers for PowerPC.
3619 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3620 registers on PowerPC targets.
3622 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3623 targets even when the libthread_db library is not available.
3625 * The GDB remote stub, gdbserver, now supports the new file transfer
3626 commands (remote put, remote get, and remote delete).
3628 * The GDB remote stub, gdbserver, now supports run and attach in
3629 extended-remote mode.
3631 * hppa*64*-*-hpux11* target broken
3632 The debugger is unable to start a program and fails with the following
3633 error: "Error trying to get information about dynamic linker".
3634 The gdb-6.7 release is also affected.
3636 * GDB now supports the --enable-targets= configure option to allow
3637 building a single GDB executable that supports multiple remote
3638 target architectures.
3640 * GDB now supports debugging C and C++ programs which use the
3641 Decimal Floating Point extension. In addition, the PowerPC target
3642 now has a set of pseudo-registers to inspect decimal float values
3643 stored in two consecutive float registers.
3645 * The -break-insert MI command can optionally create pending
3648 * Improved support for debugging Ada
3649 Many improvements to the Ada language support have been made. These
3651 - Better support for Ada2005 interface types
3652 - Improved handling of arrays and slices in general
3653 - Better support for Taft-amendment types
3654 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3656 - Improved command completion in Ada
3659 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3664 set print frame-arguments (all|scalars|none)
3665 show print frame-arguments
3666 The value of this variable can be changed to control which argument
3667 values should be printed by the debugger when displaying a frame.
3672 Transfer files to and from a remote target, and delete remote files.
3679 Transfer files to and from a remote target, and delete remote files.
3681 * New remote packets
3688 Open, close, read, write, and delete files on the remote system.
3691 Attach to an existing process on the remote system, in extended-remote
3695 Run a new process on the remote system, in extended-remote mode.
3697 *** Changes in GDB 6.7
3699 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3700 bfd, libiberty and opcodes, as revealed by static analysis donated by
3701 Coverity, Inc. (http://scan.coverity.com).
3703 * When looking up multiply-defined global symbols, GDB will now prefer the
3704 symbol definition in the current shared library if it was built using the
3705 -Bsymbolic linker option.
3707 * When the Text User Interface (TUI) is not configured, GDB will now
3708 recognize the -tui command-line option and print a message that the TUI
3711 * The GDB remote stub, gdbserver, now has lower overhead for high
3712 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3714 * GDB for MIPS targets now autodetects whether a remote target provides
3715 32-bit or 64-bit register values.
3717 * Support for C++ member pointers has been improved.
3719 * GDB now understands XML target descriptions, which specify the
3720 target's overall architecture. GDB can read a description from
3721 a local file or over the remote serial protocol.
3723 * Vectors of single-byte data use a new integer type which is not
3724 automatically displayed as character or string data.
3726 * The /s format now works with the print command. It displays
3727 arrays of single-byte integers and pointers to single-byte integers
3730 * Target descriptions can now describe target-specific registers,
3731 for architectures which have implemented the support (currently
3732 only ARM, M68K, and MIPS).
3734 * GDB and the GDB remote stub, gdbserver, now support the XScale
3737 * The GDB remote stub, gdbserver, has been updated to support
3738 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3739 has been rewritten to use the standard GDB remote protocol.
3741 * GDB can now step into C++ functions which are called through thunks.
3743 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3745 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3746 layout. It also supports a TextSeg= and DataSeg= response when only
3747 segment base addresses (rather than offsets) are available.
3749 * The /i format now outputs any trailing branch delay slot instructions
3750 immediately following the last instruction within the count specified.
3752 * The GDB remote protocol "T" stop reply packet now supports a
3753 "library" response. Combined with the new "qXfer:libraries:read"
3754 packet, this response allows GDB to debug shared libraries on targets
3755 where the operating system manages the list of loaded libraries (e.g.
3756 Windows and SymbianOS).
3758 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3759 (DLLs) on Windows and Windows CE targets.
3761 * GDB now supports a faster verification that a .debug file matches its binary
3762 according to its build-id signature, if the signature is present.
3768 Enable or disable hardware flow control (RTS/CTS) on the serial port
3769 when debugging using remote targets.
3771 set mem inaccessible-by-default
3772 show mem inaccessible-by-default
3773 If the target supplies a memory map, for instance via the remote
3774 protocol's "qXfer:memory-map:read" packet, setting this variable
3775 prevents GDB from accessing memory outside the memory map. This
3776 is useful for targets with memory mapped registers or which react
3777 badly to accesses of unmapped address space.
3779 set breakpoint auto-hw
3780 show breakpoint auto-hw
3781 If the target supplies a memory map, for instance via the remote
3782 protocol's "qXfer:memory-map:read" packet, setting this variable
3783 lets GDB use hardware breakpoints automatically for memory regions
3784 where it can not use software breakpoints. This covers both the
3785 "break" command and internal breakpoints used for other commands
3786 including "next" and "finish".
3789 catch exception unhandled
3790 Stop the program execution when Ada exceptions are raised.
3793 Stop the program execution when an Ada assertion failed.
3797 Set an alternate system root for target files. This is a more
3798 general version of "set solib-absolute-prefix", which is now
3799 an alias to "set sysroot".
3802 Provide extended SPU facility status information. This set of
3803 commands is available only when debugging the Cell/B.E. SPU
3806 * New native configurations
3808 OpenBSD/sh sh*-*openbsd*
3811 unset tdesc filename
3813 Use the specified local file as an XML target description, and do
3814 not query the target for its built-in description.
3818 OpenBSD/sh sh*-*-openbsd*
3819 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3820 Toshiba Media Processor mep-elf
3822 * New remote packets
3825 Ignore the specified signals; pass them directly to the debugged program
3826 without stopping other threads or reporting them to GDB.
3828 qXfer:features:read:
3829 Read an XML target description from the target, which describes its
3834 Read or write contents of an spufs file on the target system. These
3835 packets are available only on the Cell/B.E. SPU architecture.
3837 qXfer:libraries:read:
3838 Report the loaded shared libraries. Combined with new "T" packet
3839 response, this packet allows GDB to debug shared libraries on
3840 targets where the operating system manages the list of loaded
3841 libraries (e.g. Windows and SymbianOS).
3845 Support for these obsolete configurations has been removed.
3853 i[34567]86-*-lynxos*
3854 i[34567]86-*-netware*
3855 i[34567]86-*-sco3.2v5*
3856 i[34567]86-*-sco3.2v4*
3858 i[34567]86-*-sysv4.2*
3861 i[34567]86-*-unixware2*
3862 i[34567]86-*-unixware*
3871 * Other removed features
3878 Various m68k-only ROM monitors.
3885 Various Renesas ROM monitors and debugging interfaces for SH and
3890 Support for a Macraigor serial interface to on-chip debugging.
3891 GDB does not directly support the newer parallel or USB
3896 A debug information format. The predecessor to DWARF 2 and
3897 DWARF 3, which are still supported.
3899 Support for the HP aCC compiler on HP-UX/PA-RISC
3901 SOM-encapsulated symbolic debugging information, automatic
3902 invocation of pxdb, and the aCC custom C++ ABI. This does not
3903 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3904 with aCC can still be debugged on an assembly level.
3906 MIPS ".pdr" sections
3908 A MIPS-specific format used to describe stack frame layout
3909 in debugging information.
3913 GDB could work with an older version of Guile to debug
3914 the interpreter and Scheme programs running in it.
3916 set mips stack-arg-size
3917 set mips saved-gpreg-size
3919 Use "set mips abi" to control parameter passing for MIPS.
3921 *** Changes in GDB 6.6
3926 Cell Broadband Engine SPU spu-elf
3928 * GDB can now be configured as a cross-debugger targeting native Windows
3929 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3930 running on a Windows system over TCP/IP to debug Windows programs.
3932 * The GDB remote stub, gdbserver, has been updated to support Windows and
3933 Cygwin debugging. Both single-threaded and multi-threaded programs are
3936 * The "set trust-readonly-sections" command works again. This command was
3937 broken in GDB 6.3, 6.4, and 6.5.
3939 * The "load" command now supports writing to flash memory, if the remote
3940 stub provides the required support.
3942 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3943 longer requires symbolic debug information (e.g. DWARF-2).
3948 unset substitute-path
3949 show substitute-path
3950 Manage a list of substitution rules that GDB uses to rewrite the name
3951 of the directories where the sources are located. This can be useful
3952 for instance when the sources were moved to a different location
3953 between compilation and debugging.
3957 Print each CLI command as it is executed. Each command is prefixed with
3958 a number of `+' symbols representing the nesting depth.
3959 The source command now has a `-v' option to enable the same feature.
3963 The ARM Demon monitor support (RDP protocol, "target rdp").
3965 Kernel Object Display, an embedded debugging feature which only worked with
3966 an obsolete version of Cisco IOS.
3968 The 'set download-write-size' and 'show download-write-size' commands.
3970 * New remote packets
3973 Tell a stub about GDB client features, and request remote target features.
3974 The first feature implemented is PacketSize, which allows the target to
3975 specify the size of packets it can handle - to minimize the number of
3976 packets required and improve performance when connected to a remote
3980 Fetch an OS auxilliary vector from the remote stub. This packet is a
3981 more efficient replacement for qPart:auxv:read.
3983 qXfer:memory-map:read:
3984 Fetch a memory map from the remote stub, including information about
3985 RAM, ROM, and flash memory devices.
3990 Erase and program a flash memory device.
3992 * Removed remote packets
3995 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3996 used it, and only gdbserver implemented it.
3998 *** Changes in GDB 6.5
4002 Renesas M32C/M16C m32c-elf
4004 Morpho Technologies ms1 ms1-elf
4008 init-if-undefined Initialize a convenience variable, but
4009 only if it doesn't already have a value.
4011 The following commands are presently only implemented for native GNU/Linux:
4013 checkpoint Save a snapshot of the program state.
4015 restart <n> Return the program state to a
4016 previously saved state.
4018 info checkpoints List currently saved checkpoints.
4020 delete-checkpoint <n> Delete a previously saved checkpoint.
4022 set|show detach-on-fork Tell gdb whether to detach from a newly
4023 forked process, or to keep debugging it.
4025 info forks List forks of the user program that
4026 are available to be debugged.
4028 fork <n> Switch to debugging one of several
4029 forks of the user program that are
4030 available to be debugged.
4032 delete-fork <n> Delete a fork from the list of forks
4033 that are available to be debugged (and
4034 kill the forked process).
4036 detach-fork <n> Delete a fork from the list of forks
4037 that are available to be debugged (and
4038 allow the process to continue).
4042 Morpho Technologies ms2 ms1-elf
4044 * Improved Windows host support
4046 GDB now builds as a cross debugger hosted on i686-mingw32, including
4047 native console support, and remote communications using either
4048 network sockets or serial ports.
4050 * Improved Modula-2 language support
4052 GDB can now print most types in the Modula-2 syntax. This includes:
4053 basic types, set types, record types, enumerated types, range types,
4054 pointer types and ARRAY types. Procedure var parameters are correctly
4055 printed and hexadecimal addresses and character constants are also
4056 written in the Modula-2 syntax. Best results can be obtained by using
4057 GNU Modula-2 together with the -gdwarf-2 command line option.
4061 The ARM rdi-share module.
4063 The Netware NLM debug server.
4065 *** Changes in GDB 6.4
4067 * New native configurations
4069 OpenBSD/arm arm*-*-openbsd*
4070 OpenBSD/mips64 mips64-*-openbsd*
4074 Morpho Technologies ms1 ms1-elf
4076 * New command line options
4078 --batch-silent As for --batch, but totally silent.
4079 --return-child-result The debugger will exist with the same value
4080 the child (debugged) program exited with.
4081 --eval-command COMMAND, -ex COMMAND
4082 Execute a single GDB CLI command. This may be
4083 specified multiple times and in conjunction
4084 with the --command (-x) option.
4086 * Deprecated commands removed
4088 The following commands, that were deprecated in 2000, have been
4092 set|show arm disassembly-flavor set|show arm disassembler
4093 othernames set arm disassembler
4094 set|show remotedebug set|show debug remote
4095 set|show archdebug set|show debug arch
4096 set|show eventdebug set|show debug event
4099 * New BSD user-level threads support
4101 It is now possible to debug programs using the user-level threads
4102 library on OpenBSD and FreeBSD. Currently supported (target)
4105 FreeBSD/amd64 x86_64-*-freebsd*
4106 FreeBSD/i386 i386-*-freebsd*
4107 OpenBSD/i386 i386-*-openbsd*
4109 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4110 are not yet supported.
4112 * New support for Matsushita MN10300 w/sim added
4113 (Work in progress). mn10300-elf.
4115 * REMOVED configurations and files
4117 VxWorks and the XDR protocol *-*-vxworks
4118 Motorola MCORE mcore-*-*
4119 National Semiconductor NS32000 ns32k-*-*
4121 * New "set print array-indexes" command
4123 After turning this setting "on", GDB prints the index of each element
4124 when displaying arrays. The default is "off" to preserve the previous
4127 * VAX floating point support
4129 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4131 * User-defined command support
4133 In addition to using $arg0..$arg9 for argument passing, it is now possible
4134 to use $argc to determine now many arguments have been passed. See the
4135 section on user-defined commands in the user manual for more information.
4137 *** Changes in GDB 6.3:
4139 * New command line option
4141 GDB now accepts -l followed by a number to set the timeout for remote
4144 * GDB works with GCC -feliminate-dwarf2-dups
4146 GDB now supports a more compact representation of DWARF-2 debug
4147 information using DW_FORM_ref_addr references. These are produced
4148 by GCC with the option -feliminate-dwarf2-dups and also by some
4149 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4150 to use -feliminate-dwarf2-dups.
4152 * Internationalization
4154 When supported by the host system, GDB will be built with
4155 internationalization (libintl). The task of marking up the sources is
4156 continued, we're looking forward to our first translation.
4160 Initial support for debugging programs compiled with the GNAT
4161 implementation of the Ada programming language has been integrated
4162 into GDB. In this release, support is limited to expression evaluation.
4164 * New native configurations
4166 GNU/Linux/m32r m32r-*-linux-gnu
4170 GDB's remote protocol now includes support for the 'p' packet. This
4171 packet is used to fetch individual registers from a remote inferior.
4173 * END-OF-LIFE registers[] compatibility module
4175 GDB's internal register infrastructure has been completely rewritten.
4176 The new infrastructure making possible the implementation of key new
4177 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4180 GDB 6.3 will be the last release to include the the registers[]
4181 compatibility module that allowed out-of-date configurations to
4182 continue to work. This change directly impacts the following
4192 powerpc bdm protocol
4194 Unless there is activity to revive these configurations, they will be
4195 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4197 * OBSOLETE configurations and files
4199 Configurations that have been declared obsolete in this release have
4200 been commented out. Unless there is activity to revive these
4201 configurations, the next release of GDB will have their sources
4202 permanently REMOVED.
4211 *** Changes in GDB 6.2.1:
4213 * MIPS `break main; run' gave an heuristic-fence-post warning
4215 When attempting to run even a simple program, a warning about
4216 heuristic-fence-post being hit would be reported. This problem has
4219 * MIPS IRIX 'long double' crashed GDB
4221 When examining a long double variable, GDB would get a segmentation
4222 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4223 IRIX long double values).
4227 A bug in the VAX stack code was causing problems with the "next"
4228 command. This problem has been fixed.
4230 *** Changes in GDB 6.2:
4232 * Fix for ``many threads''
4234 On GNU/Linux systems that use the NPTL threads library, a program
4235 rapidly creating and deleting threads would confuse GDB leading to the
4238 ptrace: No such process.
4239 thread_db_get_info: cannot get thread info: generic error
4241 This problem has been fixed.
4243 * "-async" and "-noasync" options removed.
4245 Support for the broken "-noasync" option has been removed (it caused
4248 * New ``start'' command.
4250 This command runs the program until the begining of the main procedure.
4252 * New BSD Kernel Data Access Library (libkvm) interface
4254 Using ``target kvm'' it is now possible to debug kernel core dumps and
4255 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4256 platforms. Currently supported (native-only) configurations are:
4258 FreeBSD/amd64 x86_64-*-freebsd*
4259 FreeBSD/i386 i?86-*-freebsd*
4260 NetBSD/i386 i?86-*-netbsd*
4261 NetBSD/m68k m68*-*-netbsd*
4262 NetBSD/sparc sparc-*-netbsd*
4263 OpenBSD/amd64 x86_64-*-openbsd*
4264 OpenBSD/i386 i?86-*-openbsd*
4265 OpenBSD/m68k m68*-openbsd*
4266 OpenBSD/sparc sparc-*-openbsd*
4268 * Signal trampoline code overhauled
4270 Many generic problems with GDB's signal handling code have been fixed.
4271 These include: backtraces through non-contiguous stacks; recognition
4272 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4273 call; backtrace through a signal trampoline; step into and out of
4274 signal handlers; and single-stepping in the signal trampoline.
4276 Please note that kernel bugs are a limiting factor here. These
4277 features have been shown to work on an s390 GNU/Linux system that
4278 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4280 * Cygwin support for DWARF 2 added.
4282 * New native configurations
4284 GNU/Linux/hppa hppa*-*-linux*
4285 OpenBSD/hppa hppa*-*-openbsd*
4286 OpenBSD/m68k m68*-*-openbsd*
4287 OpenBSD/m88k m88*-*-openbsd*
4288 OpenBSD/powerpc powerpc-*-openbsd*
4289 NetBSD/vax vax-*-netbsd*
4290 OpenBSD/vax vax-*-openbsd*
4292 * END-OF-LIFE frame compatibility module
4294 GDB's internal frame infrastructure has been completely rewritten.
4295 The new infrastructure making it possible to support key new features
4296 including DWARF 2 Call Frame Information. To aid in the task of
4297 migrating old configurations to this new infrastructure, a
4298 compatibility module, that allowed old configurations to continue to
4299 work, was also included.
4301 GDB 6.2 will be the last release to include this frame compatibility
4302 module. This change directly impacts the following configurations:
4312 Unless there is activity to revive these configurations, they will be
4313 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4315 * REMOVED configurations and files
4317 Sun 3, running SunOS 3 m68*-*-sunos3*
4318 Sun 3, running SunOS 4 m68*-*-sunos4*
4319 Sun 2, running SunOS 3 m68000-*-sunos3*
4320 Sun 2, running SunOS 4 m68000-*-sunos4*
4321 Motorola 680x0 running LynxOS m68*-*-lynxos*
4322 AT&T 3b1/Unix pc m68*-att-*
4323 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4324 decstation mips-dec-* mips-little-*
4325 riscos mips-*-riscos* mips-*-sysv*
4326 sonymips mips-sony-*
4327 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4329 *** Changes in GDB 6.1.1:
4331 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4333 The TUI (Text-mode User Interface) is now built as part of a default
4334 GDB configuration. It is enabled by either selecting the TUI with the
4335 command line option "-i=tui" or by running the separate "gdbtui"
4336 program. For more information on the TUI, see the manual "Debugging
4339 * Pending breakpoint support (also included in GDB 6.1)
4341 Support has been added to allow you to specify breakpoints in shared
4342 libraries that have not yet been loaded. If a breakpoint location
4343 cannot be found, and the "breakpoint pending" option is set to auto,
4344 GDB queries you if you wish to make the breakpoint pending on a future
4345 shared-library load. If and when GDB resolves the breakpoint symbol,
4346 the pending breakpoint is removed as one or more regular breakpoints
4349 Pending breakpoints are very useful for GCJ Java debugging.
4351 * Fixed ISO-C build problems
4353 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4354 non ISO-C code that stopped them being built using a more strict ISO-C
4355 compiler (e.g., IBM's C compiler).
4357 * Fixed build problem on IRIX 5
4359 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4360 wasn't able to compile compile on an IRIX 5 system.
4362 * Added execute permission to gdb/gdbserver/configure
4364 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4365 permission. This bug would cause configure to fail on a number of
4366 systems (Solaris, IRIX). Ref: server/519.
4368 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4370 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4371 has been updated to use constant array sizes.
4373 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4375 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4376 its generated DWARF Call Frame Info. This encoding was causing GDB to
4377 panic, that panic has been fixed. Ref: gdb/1628.
4379 * Fixed a problem when examining parameters in shared library code.
4381 When examining parameters in optimized shared library code generated
4382 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4383 not available''. GDB now correctly displays the variable's value.
4385 *** Changes in GDB 6.1:
4387 * Removed --with-mmalloc
4389 Support for the mmalloc memory manager has been removed, as it
4390 conflicted with the internal gdb byte cache.
4392 * Changes in AMD64 configurations
4394 The AMD64 target now includes the %cs and %ss registers. As a result
4395 the AMD64 remote protocol has changed; this affects the floating-point
4396 and SSE registers. If you rely on those registers for your debugging,
4397 you should upgrade gdbserver on the remote side.
4399 * Revised SPARC target
4401 The SPARC target has been completely revised, incorporating the
4402 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4403 support for LynxOS and SunOS 4 has been dropped. Calling functions
4404 from within GDB on operating systems with a non-executable stack
4405 (Solaris, OpenBSD) now works.
4409 GDB has a new C++ demangler which does a better job on the mangled
4410 names generated by current versions of g++. It also runs faster, so
4411 with this and other changes gdb should now start faster on large C++
4414 * DWARF 2 Location Expressions
4416 GDB support for location expressions has been extended to support function
4417 arguments and frame bases. Older versions of GDB could crash when they
4420 * C++ nested types and namespaces
4422 GDB's support for nested types and namespaces in C++ has been
4423 improved, especially if you use the DWARF 2 debugging format. (This
4424 is the default for recent versions of GCC on most platforms.)
4425 Specifically, if you have a class "Inner" defined within a class or
4426 namespace "Outer", then GDB realizes that the class's name is
4427 "Outer::Inner", not simply "Inner". This should greatly reduce the
4428 frequency of complaints about not finding RTTI symbols. In addition,
4429 if you are stopped at inside of a function defined within a namespace,
4430 GDB modifies its name lookup accordingly.
4432 * New native configurations
4434 NetBSD/amd64 x86_64-*-netbsd*
4435 OpenBSD/amd64 x86_64-*-openbsd*
4436 OpenBSD/alpha alpha*-*-openbsd*
4437 OpenBSD/sparc sparc-*-openbsd*
4438 OpenBSD/sparc64 sparc64-*-openbsd*
4440 * New debugging protocols
4442 M32R with SDI protocol m32r-*-elf*
4444 * "set prompt-escape-char" command deleted.
4446 The command "set prompt-escape-char" has been deleted. This command,
4447 and its very obscure effet on GDB's prompt, was never documented,
4448 tested, nor mentioned in the NEWS file.
4450 * OBSOLETE configurations and files
4452 Configurations that have been declared obsolete in this release have
4453 been commented out. Unless there is activity to revive these
4454 configurations, the next release of GDB will have their sources
4455 permanently REMOVED.
4457 Sun 3, running SunOS 3 m68*-*-sunos3*
4458 Sun 3, running SunOS 4 m68*-*-sunos4*
4459 Sun 2, running SunOS 3 m68000-*-sunos3*
4460 Sun 2, running SunOS 4 m68000-*-sunos4*
4461 Motorola 680x0 running LynxOS m68*-*-lynxos*
4462 AT&T 3b1/Unix pc m68*-att-*
4463 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4464 decstation mips-dec-* mips-little-*
4465 riscos mips-*-riscos* mips-*-sysv*
4466 sonymips mips-sony-*
4467 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4469 * REMOVED configurations and files
4471 SGI Irix-4.x mips-sgi-irix4 or iris4
4472 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4473 Z8000 simulator z8k-zilog-none or z8ksim
4474 Matsushita MN10200 w/simulator mn10200-*-*
4475 H8/500 simulator h8500-hitachi-hms or h8500hms
4476 HP/PA running BSD hppa*-*-bsd*
4477 HP/PA running OSF/1 hppa*-*-osf*
4478 HP/PA Pro target hppa*-*-pro*
4479 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4480 386BSD i[3456]86-*-bsd*
4481 Sequent family i[3456]86-sequent-sysv4*
4482 i[3456]86-sequent-sysv*
4483 i[3456]86-sequent-bsd*
4484 SPARC running LynxOS sparc-*-lynxos*
4485 SPARC running SunOS 4 sparc-*-sunos4*
4486 Tsqware Sparclet sparclet-*-*
4487 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4489 *** Changes in GDB 6.0:
4493 Support for debugging the Objective-C programming language has been
4494 integrated into GDB.
4496 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4498 DWARF 2's Call Frame Information makes available compiler generated
4499 information that more exactly describes the program's run-time stack.
4500 By using this information, GDB is able to provide more robust stack
4503 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4504 have been updated to use a new backtrace mechanism which includes
4505 DWARF 2 CFI support.
4509 GDB's remote protocol has been extended to include support for hosted
4510 file I/O (where the remote target uses GDB's file system). See GDB's
4511 remote protocol documentation for details.
4513 * All targets using the new architecture framework.
4515 All of GDB's targets have been updated to use the new internal
4516 architecture framework. The way is now open for future GDB releases
4517 to include cross-architecture native debugging support (i386 on amd64,
4520 * GNU/Linux's Thread Local Storage (TLS)
4522 GDB now includes support for for the GNU/Linux implementation of
4523 per-thread variables.
4525 * GNU/Linux's Native POSIX Thread Library (NPTL)
4527 GDB's thread code has been updated to work with either the new
4528 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4530 * Separate debug info.
4532 GDB, in conjunction with BINUTILS, now supports a mechanism for
4533 automatically loading debug information from a separate file. Instead
4534 of shipping full debug and non-debug versions of system libraries,
4535 system integrators can now instead ship just the stripped libraries
4536 and optional debug files.
4538 * DWARF 2 Location Expressions
4540 DWARF 2 Location Expressions allow the compiler to more completely
4541 describe the location of variables (even in optimized code) to the
4544 GDB now includes preliminary support for location expressions (support
4545 for DW_OP_piece is still missing).
4549 A number of long standing bugs that caused GDB to die while starting a
4550 Java application have been fixed. GDB's Java support is now
4551 considered "useable".
4553 * GNU/Linux support for fork, vfork, and exec.
4555 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4556 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4559 * GDB supports logging output to a file
4561 There are two new commands, "set logging" and "show logging", which can be
4562 used to capture GDB's output to a file.
4564 * The meaning of "detach" has changed for gdbserver
4566 The "detach" command will now resume the application, as documented. To
4567 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4570 * d10v, m68hc11 `regs' command deprecated
4572 The `info registers' command has been updated so that it displays the
4573 registers using a format identical to the old `regs' command.
4577 A new command, "maint set profile on/off", has been added. This command can
4578 be used to enable or disable profiling while running GDB, to profile a
4579 session or a set of commands. In addition there is a new configure switch,
4580 "--enable-profiling", which will cause GDB to be compiled with profiling
4581 data, for more informative profiling results.
4583 * Default MI syntax changed to "mi2".
4585 The default MI (machine interface) syntax, enabled by the command line
4586 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4587 "mi1", can be enabled by specifying the option "-i=mi1".
4589 Support for the original "mi0" syntax (included in GDB 5.0) has been
4592 Fix for gdb/192: removed extraneous space when displaying frame level.
4593 Fix for gdb/672: update changelist is now output in mi list format.
4594 Fix for gdb/702: a -var-assign that updates the value now shows up
4595 in a subsequent -var-update.
4597 * New native configurations.
4599 FreeBSD/amd64 x86_64-*-freebsd*
4601 * Multi-arched targets.
4603 HP/PA HPUX11 hppa*-*-hpux*
4604 Renesas M32R/D w/simulator m32r-*-elf*
4606 * OBSOLETE configurations and files
4608 Configurations that have been declared obsolete in this release have
4609 been commented out. Unless there is activity to revive these
4610 configurations, the next release of GDB will have their sources
4611 permanently REMOVED.
4613 Z8000 simulator z8k-zilog-none or z8ksim
4614 Matsushita MN10200 w/simulator mn10200-*-*
4615 H8/500 simulator h8500-hitachi-hms or h8500hms
4616 HP/PA running BSD hppa*-*-bsd*
4617 HP/PA running OSF/1 hppa*-*-osf*
4618 HP/PA Pro target hppa*-*-pro*
4619 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4620 Sequent family i[3456]86-sequent-sysv4*
4621 i[3456]86-sequent-sysv*
4622 i[3456]86-sequent-bsd*
4623 Tsqware Sparclet sparclet-*-*
4624 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4626 * REMOVED configurations and files
4629 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4630 IBM AIX PS/2 i[3456]86-*-aix
4631 i386 running Mach 3.0 i[3456]86-*-mach3*
4632 i386 running Mach i[3456]86-*-mach*
4633 i386 running OSF/1 i[3456]86-*osf1mk*
4634 HP/Apollo 68k Family m68*-apollo*-sysv*,
4636 m68*-hp-bsd*, m68*-hp-hpux*
4637 Argonaut Risc Chip (ARC) arc-*-*
4638 Mitsubishi D30V d30v-*-*
4639 Fujitsu FR30 fr30-*-elf*
4640 OS/9000 i[34]86-*-os9k
4641 I960 with MON960 i960-*-coff
4643 * MIPS $fp behavior changed
4645 The convenience variable $fp, for the MIPS, now consistently returns
4646 the address of the current frame's base. Previously, depending on the
4647 context, $fp could refer to either $sp or the current frame's base
4648 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4649 The GNU Source-Level Debugger''.
4651 *** Changes in GDB 5.3:
4653 * GNU/Linux shared library multi-threaded performance improved.
4655 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4656 `/proc', in preference to `ptrace' for memory reads. This may result
4657 in an improvement in the start-up time of multi-threaded, shared
4658 library applications when run under GDB. One GDB user writes: ``loads
4659 shared libs like mad''.
4661 * ``gdbserver'' now supports multi-threaded applications on some targets
4663 Support for debugging multi-threaded applications which use
4664 the GNU/Linux LinuxThreads package has been added for
4665 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4666 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4668 * GDB now supports C/C++ preprocessor macros.
4670 GDB now expands preprocessor macro invocations in C/C++ expressions,
4671 and provides various commands for showing macro definitions and how
4674 The new command `macro expand EXPRESSION' expands any macro
4675 invocations in expression, and shows the result.
4677 The new command `show macro MACRO-NAME' shows the definition of the
4678 macro named MACRO-NAME, and where it was defined.
4680 Most compilers don't include information about macros in the debugging
4681 information by default. In GCC 3.1, for example, you need to compile
4682 your program with the options `-gdwarf-2 -g3'. If the macro
4683 information is present in the executable, GDB will read it.
4685 * Multi-arched targets.
4687 DEC Alpha (partial) alpha*-*-*
4688 DEC VAX (partial) vax-*-*
4690 National Semiconductor NS32000 (partial) ns32k-*-*
4691 Motorola 68000 (partial) m68k-*-*
4692 Motorola MCORE mcore-*-*
4696 Fujitsu FRV architecture added by Red Hat frv*-*-*
4699 * New native configurations
4701 Alpha NetBSD alpha*-*-netbsd*
4702 SH NetBSD sh*-*-netbsdelf*
4703 MIPS NetBSD mips*-*-netbsd*
4704 UltraSPARC NetBSD sparc64-*-netbsd*
4706 * OBSOLETE configurations and files
4708 Configurations that have been declared obsolete in this release have
4709 been commented out. Unless there is activity to revive these
4710 configurations, the next release of GDB will have their sources
4711 permanently REMOVED.
4713 Mitsubishi D30V d30v-*-*
4714 OS/9000 i[34]86-*-os9k
4715 IBM AIX PS/2 i[3456]86-*-aix
4716 Fujitsu FR30 fr30-*-elf*
4717 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4718 Argonaut Risc Chip (ARC) arc-*-*
4719 i386 running Mach 3.0 i[3456]86-*-mach3*
4720 i386 running Mach i[3456]86-*-mach*
4721 i386 running OSF/1 i[3456]86-*osf1mk*
4722 HP/Apollo 68k Family m68*-apollo*-sysv*,
4724 m68*-hp-bsd*, m68*-hp-hpux*
4725 I960 with MON960 i960-*-coff
4727 * OBSOLETE languages
4729 CHILL, a Pascal like language used by telecommunications companies.
4731 * REMOVED configurations and files
4733 AMD 29k family via UDI a29k-amd-udi, udi29k
4734 A29K VxWorks a29k-*-vxworks
4735 AMD 29000 embedded, using EBMON a29k-none-none
4736 AMD 29000 embedded with COFF a29k-none-coff
4737 AMD 29000 embedded with a.out a29k-none-aout
4739 testsuite/gdb.hp/gdb.threads-hp/ directory
4741 * New command "set max-user-call-depth <nnn>"
4743 This command allows the user to limit the call depth of user-defined
4744 commands. The default is 1024.
4746 * Changes in FreeBSD/i386 native debugging.
4748 Support for the "generate-core-file" has been added.
4750 * New commands "dump", "append", and "restore".
4752 These commands allow data to be copied from target memory
4753 to a bfd-format or binary file (dump and append), and back
4754 from a file into memory (restore).
4756 * Improved "next/step" support on multi-processor Alpha Tru64.
4758 The previous single-step mechanism could cause unpredictable problems,
4759 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4760 of a software single-step mechanism prevents this.
4762 *** Changes in GDB 5.2.1:
4770 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4771 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4772 Fix, by Joel Brobecker imported from mainline.
4774 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4775 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4776 Fix, by Fred Fish, imported from mainline.
4778 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4779 Surprisingly enough, it works now.
4780 By Michal Ludvig, imported from mainline.
4782 i386 hardware watchpoint support:
4783 avoid misses on second run for some targets.
4784 By Pierre Muller, imported from mainline.
4786 *** Changes in GDB 5.2:
4788 * New command "set trust-readonly-sections on[off]".
4790 This command is a hint that tells gdb that read-only sections
4791 really are read-only (ie. that their contents will not change).
4792 In this mode, gdb will go to the object file rather than the
4793 target to read memory from read-only sections (such as ".text").
4794 This can be a significant performance improvement on some
4795 (notably embedded) targets.
4797 * New command "generate-core-file" (or "gcore").
4799 This new gdb command allows the user to drop a core file of the child
4800 process state at any time. So far it's been implemented only for
4801 GNU/Linux and Solaris, but should be relatively easily ported to other
4802 hosts. Argument is core file name (defaults to core.<pid>).
4804 * New command line option
4806 GDB now accepts --pid or -p followed by a process id.
4808 * Change in command line behavior -- corefiles vs. process ids.
4810 There is a subtle behavior in the way in which GDB handles
4811 command line arguments. The first non-flag argument is always
4812 a program to debug, but the second non-flag argument may either
4813 be a corefile or a process id. Previously, GDB would attempt to
4814 open the second argument as a corefile, and if that failed, would
4815 issue a superfluous error message and then attempt to attach it as
4816 a process. Now, if the second argument begins with a non-digit,
4817 it will be treated as a corefile. If it begins with a digit,
4818 GDB will attempt to attach it as a process, and if no such process
4819 is found, will then attempt to open it as a corefile.
4821 * Changes in ARM configurations.
4823 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4824 configuration is fully multi-arch.
4826 * New native configurations
4828 ARM NetBSD arm*-*-netbsd*
4829 x86 OpenBSD i[3456]86-*-openbsd*
4830 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4831 Sparc64 running FreeBSD sparc64-*-freebsd*
4835 Sanyo XStormy16 xstormy16-elf
4837 * OBSOLETE configurations and files
4839 Configurations that have been declared obsolete in this release have
4840 been commented out. Unless there is activity to revive these
4841 configurations, the next release of GDB will have their sources
4842 permanently REMOVED.
4844 AMD 29k family via UDI a29k-amd-udi, udi29k
4845 A29K VxWorks a29k-*-vxworks
4846 AMD 29000 embedded, using EBMON a29k-none-none
4847 AMD 29000 embedded with COFF a29k-none-coff
4848 AMD 29000 embedded with a.out a29k-none-aout
4850 testsuite/gdb.hp/gdb.threads-hp/ directory
4852 * REMOVED configurations and files
4854 TI TMS320C80 tic80-*-*
4856 PowerPC Solaris powerpcle-*-solaris*
4857 PowerPC Windows NT powerpcle-*-cygwin32
4858 PowerPC Netware powerpc-*-netware*
4859 Harris/CXUX m88k m88*-harris-cxux*
4860 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4861 ns32k-utek-sysv* ns32k-utek-*
4862 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4863 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4864 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4865 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4866 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4868 * Changes to command line processing
4870 The new `--args' feature can be used to specify command-line arguments
4871 for the inferior from gdb's command line.
4873 * Changes to key bindings
4875 There is a new `operate-and-get-next' function bound to `C-o'.
4877 *** Changes in GDB 5.1.1
4879 Fix compile problem on DJGPP.
4881 Fix a problem with floating-point registers on the i386 being
4884 Fix to stop GDB crashing on .debug_str debug info.
4886 Numerous documentation fixes.
4888 Numerous testsuite fixes.
4890 *** Changes in GDB 5.1:
4892 * New native configurations
4894 Alpha FreeBSD alpha*-*-freebsd*
4895 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4896 MIPS GNU/Linux mips*-*-linux*
4897 MIPS SGI Irix 6.x mips*-sgi-irix6*
4898 ia64 AIX ia64-*-aix*
4899 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4903 Motorola 68HC11 and 68HC12 m68hc11-elf
4905 UltraSparc running GNU/Linux sparc64-*-linux*
4907 * OBSOLETE configurations and files
4909 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4910 Harris/CXUX m88k m88*-harris-cxux*
4911 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4912 ns32k-utek-sysv* ns32k-utek-*
4913 TI TMS320C80 tic80-*-*
4915 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4916 PowerPC Solaris powerpcle-*-solaris*
4917 PowerPC Windows NT powerpcle-*-cygwin32
4918 PowerPC Netware powerpc-*-netware*
4919 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4920 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4921 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4922 Apple Macintosh (MPW) host N/A
4924 stuff.c (Program to stuff files into a specially prepared space in kdb)
4925 kdb-start.c (Main loop for the standalone kernel debugger)
4927 Configurations that have been declared obsolete in this release have
4928 been commented out. Unless there is activity to revive these
4929 configurations, the next release of GDB will have their sources
4930 permanently REMOVED.
4932 * REMOVED configurations and files
4934 Altos 3068 m68*-altos-*
4935 Convex c1-*-*, c2-*-*
4937 ARM RISCix arm-*-* (as host)
4941 * GDB has been converted to ISO C.
4943 GDB's source code has been converted to ISO C. In particular, the
4944 sources are fully protoized, and rely on standard headers being
4949 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4951 * The MI enabled by default.
4953 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4954 revised and enabled by default. Packages which use GDB as a debugging
4955 engine behind a UI or another front end are encouraged to switch to
4956 using the GDB/MI interface, instead of the old annotations interface
4957 which is now deprecated.
4959 * Support for debugging Pascal programs.
4961 GDB now includes support for debugging Pascal programs. The following
4962 main features are supported:
4964 - Pascal-specific data types such as sets;
4966 - automatic recognition of Pascal sources based on file-name
4969 - Pascal-style display of data types, variables, and functions;
4971 - a Pascal expression parser.
4973 However, some important features are not yet supported.
4975 - Pascal string operations are not supported at all;
4977 - there are some problems with boolean types;
4979 - Pascal type hexadecimal constants are not supported
4980 because they conflict with the internal variables format;
4982 - support for Pascal objects and classes is not full yet;
4984 - unlike Pascal, GDB is case-sensitive for symbol names.
4986 * Changes in completion.
4988 Commands such as `shell', `run' and `set args', which pass arguments
4989 to inferior programs, now complete on file names, similar to what
4990 users expect at the shell prompt.
4992 Commands which accept locations, such as `disassemble', `print',
4993 `breakpoint', `until', etc. now complete on filenames as well as
4994 program symbols. Thus, if you type "break foob TAB", and the source
4995 files linked into the programs include `foobar.c', that file name will
4996 be one of the candidates for completion. However, file names are not
4997 considered for completion after you typed a colon that delimits a file
4998 name from a name of a function in that file, as in "break foo.c:bar".
5000 `set demangle-style' completes on available demangling styles.
5002 * New platform-independent commands:
5004 It is now possible to define a post-hook for a command as well as a
5005 hook that runs before the command. For more details, see the
5006 documentation of `hookpost' in the GDB manual.
5008 * Changes in GNU/Linux native debugging.
5010 Support for debugging multi-threaded programs has been completely
5011 revised for all platforms except m68k and sparc. You can now debug as
5012 many threads as your system allows you to have.
5014 Attach/detach is supported for multi-threaded programs.
5016 Support for SSE registers was added for x86. This doesn't work for
5017 multi-threaded programs though.
5019 * Changes in MIPS configurations.
5021 Multi-arch support is enabled for all MIPS configurations.
5023 GDB can now be built as native debugger on SGI Irix 6.x systems for
5024 debugging n32 executables. (Debugging 64-bit executables is not yet
5027 * Unified support for hardware watchpoints in all x86 configurations.
5029 Most (if not all) native x86 configurations support hardware-assisted
5030 breakpoints and watchpoints in a unified manner. This support
5031 implements debug register sharing between watchpoints, which allows to
5032 put a virtually infinite number of watchpoints on the same address,
5033 and also supports watching regions up to 16 bytes with several debug
5036 The new maintenance command `maintenance show-debug-regs' toggles
5037 debugging print-outs in functions that insert, remove, and test
5038 watchpoints and hardware breakpoints.
5040 * Changes in the DJGPP native configuration.
5042 New command ``info dos sysinfo'' displays assorted information about
5043 the CPU, OS, memory, and DPMI server.
5045 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5046 display information about segment descriptors stored in GDT, LDT, and
5049 New commands ``info dos pde'' and ``info dos pte'' display entries
5050 from Page Directory and Page Tables (for now works with CWSDPMI only).
5051 New command ``info dos address-pte'' displays the Page Table entry for
5052 a given linear address.
5054 GDB can now pass command lines longer than 126 characters to the
5055 program being debugged (requires an update to the libdbg.a library
5056 which is part of the DJGPP development kit).
5058 DWARF2 debug info is now supported.
5060 It is now possible to `step' and `next' through calls to `longjmp'.
5062 * Changes in documentation.
5064 All GDB documentation was converted to GFDL, the GNU Free
5065 Documentation License.
5067 Tracepoints-related commands are now fully documented in the GDB
5070 TUI, the Text-mode User Interface, is now documented in the manual.
5072 Tracepoints-related commands are now fully documented in the GDB
5075 The "GDB Internals" manual now has an index. It also includes
5076 documentation of `ui_out' functions, GDB coding standards, x86
5077 hardware watchpoints, and memory region attributes.
5079 * GDB's version number moved to ``version.in''
5081 The Makefile variable VERSION has been replaced by the file
5082 ``version.in''. People creating GDB distributions should update the
5083 contents of this file.
5087 GUD support is now a standard part of the EMACS distribution.
5089 *** Changes in GDB 5.0:
5091 * Improved support for debugging FP programs on x86 targets
5093 Unified and much-improved support for debugging floating-point
5094 programs on all x86 targets. In particular, ``info float'' now
5095 displays the FP registers in the same format on all x86 targets, with
5096 greater level of detail.
5098 * Improvements and bugfixes in hardware-assisted watchpoints
5100 It is now possible to watch array elements, struct members, and
5101 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5102 on x86 targets no longer erroneously trigger when the address is
5105 * Improvements in the native DJGPP version of GDB
5107 The distribution now includes all the scripts and auxiliary files
5108 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5109 machines ``out of the box''.
5111 The DJGPP version can now debug programs that use signals. It is
5112 possible to catch signals that happened in the debuggee, deliver
5113 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5114 would kill the program being debugged.) Programs that hook hardware
5115 interrupts (keyboard, timer, etc.) can also be debugged.
5117 It is now possible to debug DJGPP programs that redirect their
5118 standard handles or switch them to raw (as opposed to cooked) mode, or
5119 even close them. The command ``run < foo > bar'' works as expected,
5120 and ``info terminal'' reports useful information about the debuggee's
5121 terminal, including raw/cooked mode, redirection, etc.
5123 The DJGPP version now uses termios functions for console I/O, which
5124 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5127 DOS-style file names with drive letters are now fully supported by
5130 It is now possible to debug DJGPP programs that switch their working
5131 directory. It is also possible to rerun the debuggee any number of
5132 times without restarting GDB; thus, you can use the same setup,
5133 breakpoints, etc. for many debugging sessions.
5135 * New native configurations
5137 ARM GNU/Linux arm*-*-linux*
5138 PowerPC GNU/Linux powerpc-*-linux*
5142 Motorola MCore mcore-*-*
5143 x86 VxWorks i[3456]86-*-vxworks*
5144 PowerPC VxWorks powerpc-*-vxworks*
5145 TI TMS320C80 tic80-*-*
5147 * OBSOLETE configurations
5149 Altos 3068 m68*-altos-*
5150 Convex c1-*-*, c2-*-*
5152 ARM RISCix arm-*-* (as host)
5155 Configurations that have been declared obsolete will be commented out,
5156 but the code will be left in place. If there is no activity to revive
5157 these configurations before the next release of GDB, the sources will
5158 be permanently REMOVED.
5160 * Gould support removed
5162 Support for the Gould PowerNode and NP1 has been removed.
5164 * New features for SVR4
5166 On SVR4 native platforms (such as Solaris), if you attach to a process
5167 without first loading a symbol file, GDB will now attempt to locate and
5168 load symbols from the running process's executable file.
5170 * Many C++ enhancements
5172 C++ support has been greatly improved. Overload resolution now works properly
5173 in almost all cases. RTTI support is on the way.
5175 * Remote targets can connect to a sub-program
5177 A popen(3) style serial-device has been added. This device starts a
5178 sub-process (such as a stand-alone simulator) and then communicates
5179 with that. The sub-program to run is specified using the syntax
5180 ``|<program> <args>'' vis:
5182 (gdb) set remotedebug 1
5183 (gdb) target extended-remote |mn10300-elf-sim program-args
5185 * MIPS 64 remote protocol
5187 A long standing bug in the mips64 remote protocol where by GDB
5188 expected certain 32 bit registers (ex SR) to be transfered as 32
5189 instead of 64 bits has been fixed.
5191 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5192 added to provide backward compatibility with older versions of GDB.
5194 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5196 The command ``set remotebinarydownload'' command has been replaced by
5197 ``set remote X-packet''. Other commands in ``set remote'' family
5198 include ``set remote P-packet''.
5200 * Breakpoint commands accept ranges.
5202 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5203 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5204 ``tracepoint passcount'' also accepts a range of tracepoints.
5206 * ``apropos'' command added.
5208 The ``apropos'' command searches through command names and
5209 documentation strings, printing out matches, making it much easier to
5210 try to find a command that does what you are looking for.
5214 A new machine oriented interface (MI) has been added to GDB. This
5215 interface is designed for debug environments running GDB as a separate
5216 process. This is part of the long term libGDB project. See the
5217 "GDB/MI" chapter of the GDB manual for further information. It can be
5218 enabled by configuring with:
5220 .../configure --enable-gdbmi
5222 *** Changes in GDB-4.18:
5224 * New native configurations
5226 HP-UX 10.20 hppa*-*-hpux10.20
5227 HP-UX 11.x hppa*-*-hpux11.0*
5228 M68K GNU/Linux m68*-*-linux*
5232 Fujitsu FR30 fr30-*-elf*
5233 Intel StrongARM strongarm-*-*
5234 Mitsubishi D30V d30v-*-*
5236 * OBSOLETE configurations
5238 Gould PowerNode, NP1 np1-*-*, pn-*-*
5240 Configurations that have been declared obsolete will be commented out,
5241 but the code will be left in place. If there is no activity to revive
5242 these configurations before the next release of GDB, the sources will
5243 be permanently REMOVED.
5247 As a compatibility experiment, GDB's source files buildsym.h and
5248 buildsym.c have been converted to pure standard C, no longer
5249 containing any K&R compatibility code. We believe that all systems in
5250 use today either come with a standard C compiler, or have a GCC port
5251 available. If this is not true, please report the affected
5252 configuration to bug-gdb@gnu.org immediately. See the README file for
5253 information about getting a standard C compiler if you don't have one
5258 GDB now uses readline 2.2.
5260 * set extension-language
5262 You can now control the mapping between filename extensions and source
5263 languages by using the `set extension-language' command. For instance,
5264 you can ask GDB to treat .c files as C++ by saying
5265 set extension-language .c c++
5266 The command `info extensions' lists all of the recognized extensions
5267 and their associated languages.
5269 * Setting processor type for PowerPC and RS/6000
5271 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5272 you can use the `set processor' command to specify what variant of the
5273 PowerPC family you are debugging. The command
5277 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5278 following PowerPC and RS6000 variants:
5280 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5281 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5283 403GC IBM PowerPC 403GC
5284 505 Motorola PowerPC 505
5285 860 Motorola PowerPC 860 or 850
5286 601 Motorola PowerPC 601
5287 602 Motorola PowerPC 602
5288 603 Motorola/IBM PowerPC 603 or 603e
5289 604 Motorola PowerPC 604 or 604e
5290 750 Motorola/IBM PowerPC 750 or 750
5292 At the moment, this command just tells GDB what to name the
5293 special-purpose processor registers. Since almost all the affected
5294 registers are inaccessible to user-level programs, this command is
5295 only useful for remote debugging in its present form.
5299 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5300 more extensive support for HP-UX. Added features include shared
5301 library support, kernel threads and hardware watchpoints for 11.00,
5302 support for HP's ANSI C and C++ compilers, and a compatibility mode
5303 for xdb and dbx commands.
5307 HP's donation includes the new concept of catchpoints, which is a
5308 generalization of the old catch command. On HP-UX, it is now possible
5309 to catch exec, fork, and vfork, as well as library loading.
5311 This means that the existing catch command has changed; its first
5312 argument now specifies the type of catch to be set up. See the
5313 output of "help catch" for a list of catchpoint types.
5315 * Debugging across forks
5317 On HP-UX, you can choose which process to debug when a fork() happens
5322 HP has donated a curses-based terminal user interface (TUI). To get
5323 it, build with --enable-tui. Although this can be enabled for any
5324 configuration, at present it only works for native HP debugging.
5326 * GDB remote protocol additions
5328 A new protocol packet 'X' that writes binary data is now available.
5329 Default behavior is to try 'X', then drop back to 'M' if the stub
5330 fails to respond. The settable variable `remotebinarydownload'
5331 allows explicit control over the use of 'X'.
5333 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5334 full 64-bit address. The command
5336 set remoteaddresssize 32
5338 can be used to revert to the old behaviour. For existing remote stubs
5339 the change should not be noticed, as the additional address information
5342 In order to assist in debugging stubs, you may use the maintenance
5343 command `packet' to send any text string to the stub. For instance,
5345 maint packet heythere
5347 sends the packet "$heythere#<checksum>". Note that it is very easy to
5348 disrupt a debugging session by sending the wrong packet at the wrong
5351 The compare-sections command allows you to compare section data on the
5352 target to what is in the executable file without uploading or
5353 downloading, by comparing CRC checksums.
5355 * Tracing can collect general expressions
5357 You may now collect general expressions at tracepoints. This requires
5358 further additions to the target-side stub; see tracepoint.c and
5359 doc/agentexpr.texi for further details.
5361 * mask-address variable for Mips
5363 For Mips targets, you may control the zeroing of the upper 32 bits of
5364 a 64-bit address by entering `set mask-address on'. This is mainly
5365 of interest to users of embedded R4xxx and R5xxx processors.
5367 * Higher serial baud rates
5369 GDB's serial code now allows you to specify baud rates 57600, 115200,
5370 230400, and 460800 baud. (Note that your host system may not be able
5371 to achieve all of these rates.)
5375 The i960 configuration now includes an initial implementation of a
5376 builtin simulator, contributed by Jim Wilson.
5379 *** Changes in GDB-4.17:
5381 * New native configurations
5383 Alpha GNU/Linux alpha*-*-linux*
5384 Unixware 2.x i[3456]86-unixware2*
5385 Irix 6.x mips*-sgi-irix6*
5386 PowerPC GNU/Linux powerpc-*-linux*
5387 PowerPC Solaris powerpcle-*-solaris*
5388 Sparc GNU/Linux sparc-*-linux*
5389 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5393 Argonaut Risc Chip (ARC) arc-*-*
5394 Hitachi H8/300S h8300*-*-*
5395 Matsushita MN10200 w/simulator mn10200-*-*
5396 Matsushita MN10300 w/simulator mn10300-*-*
5397 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5398 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5399 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5400 Mitsubishi D10V w/simulator d10v-*-*
5401 Mitsubishi M32R/D w/simulator m32r-*-elf*
5402 Tsqware Sparclet sparclet-*-*
5403 NEC V850 w/simulator v850-*-*
5405 * New debugging protocols
5407 ARM with RDI protocol arm*-*-*
5408 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5409 DDB and LSI variants of PMON protocol mips*-*-*
5410 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5411 PowerPC with SDS protocol powerpc{,le}-*-eabi
5412 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5416 All configurations can now understand and use the DWARF 2 debugging
5417 format. The choice is automatic, if the symbol file contains DWARF 2
5422 GDB now includes basic Java language support. This support is
5423 only useful with Java compilers that produce native machine code.
5425 * solib-absolute-prefix and solib-search-path
5427 For SunOS and SVR4 shared libraries, you may now set the prefix for
5428 loading absolute shared library symbol files, and the search path for
5429 locating non-absolute shared library symbol files.
5431 * Live range splitting
5433 GDB can now effectively debug code for which GCC has performed live
5434 range splitting as part of its optimization. See gdb/doc/LRS for
5435 more details on the expected format of the stabs information.
5439 GDB's support for the GNU Hurd, including thread debugging, has been
5440 updated to work with current versions of the Hurd.
5444 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5445 instruction set. ARM GDB automatically detects when Thumb
5446 instructions are in use, and adjusts disassembly and backtracing
5451 GDB's MIPS target configurations now handle the MIP16 16-bit
5456 GDB now includes support for overlays; if an executable has been
5457 linked such that multiple sections are based at the same address, GDB
5458 will decide which section to use for symbolic info. You can choose to
5459 control the decision manually, using overlay commands, or implement
5460 additional target-side support and use "overlay load-target" to bring
5461 in the overlay mapping. Do "help overlay" for more detail.
5465 The command "info symbol <address>" displays information about
5466 the symbol at the specified address.
5470 The standard remote protocol now includes an extension that allows
5471 asynchronous collection and display of trace data. This requires
5472 extensive support in the target-side debugging stub. Tracing mode
5473 includes a new interaction mode in GDB and new commands: see the
5474 file tracepoint.c for more details.
5478 Configurations for embedded MIPS now include a simulator contributed
5479 by Cygnus Solutions. The simulator supports the instruction sets
5480 of most MIPS variants.
5484 Sparc configurations may now include the ERC32 simulator contributed
5485 by the European Space Agency. The simulator is not built into
5486 Sparc targets by default; configure with --enable-sim to include it.
5490 For target configurations that may include multiple variants of a
5491 basic architecture (such as MIPS and SH), you may now set the
5492 architecture explicitly. "set arch" sets, "info arch" lists
5493 the possible architectures.
5495 *** Changes in GDB-4.16:
5497 * New native configurations
5499 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5500 M68K NetBSD m68k-*-netbsd*
5501 PowerPC AIX 4.x powerpc-*-aix*
5502 PowerPC MacOS powerpc-*-macos*
5503 PowerPC Windows NT powerpcle-*-cygwin32
5504 RS/6000 AIX 4.x rs6000-*-aix4*
5508 ARM with RDP protocol arm-*-*
5509 I960 with MON960 i960-*-coff
5510 MIPS VxWorks mips*-*-vxworks*
5511 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5512 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5514 Matra Sparclet sparclet-*-*
5518 The powerpc-eabi configuration now includes the PSIM simulator,
5519 contributed by Andrew Cagney, with assistance from Mike Meissner.
5520 PSIM is a very elaborate model of the PowerPC, including not only
5521 basic instruction set execution, but also details of execution unit
5522 performance and I/O hardware. See sim/ppc/README for more details.
5526 GDB now works with Solaris 2.5.
5528 * Windows 95/NT native
5530 GDB will now work as a native debugger on Windows 95 and Windows NT.
5531 To build it from source, you must use the "gnu-win32" environment,
5532 which uses a DLL to emulate enough of Unix to run the GNU tools.
5533 Further information, binaries, and sources are available at
5534 ftp.cygnus.com, under pub/gnu-win32.
5536 * dont-repeat command
5538 If a user-defined command includes the command `dont-repeat', then the
5539 command will not be repeated if the user just types return. This is
5540 useful if the command is time-consuming to run, so that accidental
5541 extra keystrokes don't run the same command many times.
5543 * Send break instead of ^C
5545 The standard remote protocol now includes an option to send a break
5546 rather than a ^C to the target in order to interrupt it. By default,
5547 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5549 * Remote protocol timeout
5551 The standard remote protocol includes a new variable `remotetimeout'
5552 that allows you to set the number of seconds before GDB gives up trying
5553 to read from the target. The default value is 2.
5555 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5557 By default GDB will automatically keep track of objects as they are
5558 loaded and unloaded by the dynamic linker. By using the command `set
5559 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5560 when shared library events occur, thus allowing you to set breakpoints
5561 in shared libraries which are explicitly loaded by the inferior.
5563 Note this feature does not work on hpux8. On hpux9 you must link
5564 /usr/lib/end.o into your program. This feature should work
5565 automatically on hpux10.
5567 * Irix 5.x hardware watchpoint support
5569 Irix 5 configurations now support the use of hardware watchpoints.
5571 * Mips protocol "SYN garbage limit"
5573 When debugging a Mips target using the `target mips' protocol, you
5574 may set the number of characters that GDB will ignore by setting
5575 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5576 every character. The default value is 1050.
5578 * Recording and replaying remote debug sessions
5580 If you set `remotelogfile' to the name of a file, gdb will write to it
5581 a recording of a remote debug session. This recording may then be
5582 replayed back to gdb using "gdbreplay". See gdbserver/README for
5583 details. This is useful when you have a problem with GDB while doing
5584 remote debugging; you can make a recording of the session and send it
5585 to someone else, who can then recreate the problem.
5587 * Speedups for remote debugging
5589 GDB includes speedups for downloading and stepping MIPS systems using
5590 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5591 and more efficient S-record downloading.
5593 * Memory use reductions and statistics collection
5595 GDB now uses less memory and reports statistics about memory usage.
5596 Try the `maint print statistics' command, for example.
5598 *** Changes in GDB-4.15:
5600 * Psymtabs for XCOFF
5602 The symbol reader for AIX GDB now uses partial symbol tables. This
5603 can greatly improve startup time, especially for large executables.
5605 * Remote targets use caching
5607 Remote targets now use a data cache to speed up communication with the
5608 remote side. The data cache could lead to incorrect results because
5609 it doesn't know about volatile variables, thus making it impossible to
5610 debug targets which use memory mapped I/O devices. `set remotecache
5611 off' turns the the data cache off.
5613 * Remote targets may have threads
5615 The standard remote protocol now includes support for multiple threads
5616 in the target system, using new protocol commands 'H' and 'T'. See
5617 gdb/remote.c for details.
5621 If GDB is configured with `--enable-netrom', then it will include
5622 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5623 acts as though it is a bank of ROM on the target board, but you can
5624 write into it over the network. GDB's support consists only of
5625 support for fast loading into the emulated ROM; to debug, you must use
5626 another protocol, such as standard remote protocol. The usual
5627 sequence is something like
5629 target nrom <netrom-hostname>
5631 target remote <netrom-hostname>:1235
5635 GDB now includes support for the Apple Macintosh, as a host only. It
5636 may be run as either an MPW tool or as a standalone application, and
5637 it can debug through the serial port. All the usual GDB commands are
5638 available, but to the target command, you must supply "serial" as the
5639 device type instead of "/dev/ttyXX". See mpw-README in the main
5640 directory for more information on how to build. The MPW configuration
5641 scripts */mpw-config.in support only a few targets, and only the
5642 mips-idt-ecoff target has been tested.
5646 GDB configuration now uses autoconf. This is not user-visible,
5647 but does simplify configuration and building.
5651 GDB now supports hpux10.
5653 *** Changes in GDB-4.14:
5655 * New native configurations
5657 x86 FreeBSD i[345]86-*-freebsd
5658 x86 NetBSD i[345]86-*-netbsd
5659 NS32k NetBSD ns32k-*-netbsd
5660 Sparc NetBSD sparc-*-netbsd
5664 A29K VxWorks a29k-*-vxworks
5665 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5666 CPU32 EST-300 emulator m68*-*-est*
5667 PowerPC ELF powerpc-*-elf
5670 * Alpha OSF/1 support for procfs
5672 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5673 possible to attach to running processes. As the mounting of the /proc
5674 filesystem is optional on the Alpha, GDB automatically determines
5675 the availability of /proc during startup. This can lead to problems
5676 if /proc is unmounted after GDB has been started.
5678 * Arguments to user-defined commands
5680 User commands may accept up to 10 arguments separated by whitespace.
5681 Arguments are accessed within the user command via $arg0..$arg9. A
5684 print $arg0 + $arg1 + $arg2
5686 To execute the command use:
5689 Defines the command "adder" which prints the sum of its three arguments.
5690 Note the arguments are text substitutions, so they may reference variables,
5691 use complex expressions, or even perform inferior function calls.
5693 * New `if' and `while' commands
5695 This makes it possible to write more sophisticated user-defined
5696 commands. Both commands take a single argument, which is the
5697 expression to evaluate, and must be followed by the commands to
5698 execute, one per line, if the expression is nonzero, the list being
5699 terminated by the word `end'. The `if' command list may include an
5700 `else' word, which causes the following commands to be executed only
5701 if the expression is zero.
5703 * Fortran source language mode
5705 GDB now includes partial support for Fortran 77. It will recognize
5706 Fortran programs and can evaluate a subset of Fortran expressions, but
5707 variables and functions may not be handled correctly. GDB will work
5708 with G77, but does not yet know much about symbols emitted by other
5711 * Better HPUX support
5713 Most debugging facilities now work on dynamic executables for HPPAs
5714 running hpux9 or later. You can attach to running dynamically linked
5715 processes, but by default the dynamic libraries will be read-only, so
5716 for instance you won't be able to put breakpoints in them. To change
5717 that behavior do the following before running the program:
5723 This will cause the libraries to be mapped private and read-write.
5724 To revert to the normal behavior, do this:
5730 You cannot set breakpoints or examine data in the library until after
5731 the library is loaded if the function/data symbols do not have
5734 GDB can now also read debug symbols produced by the HP C compiler on
5735 HPPAs (sorry, no C++, Fortran or 68k support).
5737 * Target byte order now dynamically selectable
5739 You can choose which byte order to use with a target system, via the
5740 commands "set endian big" and "set endian little", and you can see the
5741 current setting by using "show endian". You can also give the command
5742 "set endian auto", in which case GDB will use the byte order
5743 associated with the executable. Currently, only embedded MIPS
5744 configurations support dynamic selection of target byte order.
5746 * New DOS host serial code
5748 This version uses DPMI interrupts to handle buffered I/O, so you
5749 no longer need to run asynctsr when debugging boards connected to
5752 *** Changes in GDB-4.13:
5754 * New "complete" command
5756 This lists all the possible completions for the rest of the line, if it
5757 were to be given as a command itself. This is intended for use by emacs.
5759 * Trailing space optional in prompt
5761 "set prompt" no longer adds a space for you after the prompt you set. This
5762 allows you to set a prompt which ends in a space or one that does not.
5764 * Breakpoint hit counts
5766 "info break" now displays a count of the number of times the breakpoint
5767 has been hit. This is especially useful in conjunction with "ignore"; you
5768 can ignore a large number of breakpoint hits, look at the breakpoint info
5769 to see how many times the breakpoint was hit, then run again, ignoring one
5770 less than that number, and this will get you quickly to the last hit of
5773 * Ability to stop printing at NULL character
5775 "set print null-stop" will cause GDB to stop printing the characters of
5776 an array when the first NULL is encountered. This is useful when large
5777 arrays actually contain only short strings.
5779 * Shared library breakpoints
5781 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5782 breakpoints in shared libraries before the executable is run.
5784 * Hardware watchpoints
5786 There is a new hardware breakpoint for the watch command for sparclite
5787 targets. See gdb/sparclite/hw_breakpoint.note.
5789 Hardware watchpoints are also now supported under GNU/Linux.
5793 Annotations have been added. These are for use with graphical interfaces,
5794 and are still experimental. Currently only gdba.el uses these.
5796 * Improved Irix 5 support
5798 GDB now works properly with Irix 5.2.
5800 * Improved HPPA support
5802 GDB now works properly with the latest GCC and GAS.
5804 * New native configurations
5806 Sequent PTX4 i[34]86-sequent-ptx4
5807 HPPA running OSF/1 hppa*-*-osf*
5808 Atari TT running SVR4 m68*-*-sysv4*
5809 RS/6000 LynxOS rs6000-*-lynxos*
5813 OS/9000 i[34]86-*-os9k
5814 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5817 * Hitachi SH7000 and E7000-PC ICE support
5819 There is now support for communicating with the Hitachi E7000-PC ICE.
5820 This is available automatically when GDB is configured for the SH.
5824 As usual, a variety of small fixes and improvements, both generic
5825 and configuration-specific. See the ChangeLog for more detail.
5827 *** Changes in GDB-4.12:
5829 * Irix 5 is now supported
5833 GDB-4.12 on the HPPA has a number of changes which make it unable
5834 to debug the output from the currently released versions of GCC and
5835 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5836 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5837 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5840 *** Changes in GDB-4.11:
5842 * User visible changes:
5846 The "set remotedebug" option is now consistent between the mips remote
5847 target, remote targets using the gdb-specific protocol, UDI (AMD's
5848 debug protocol for the 29k) and the 88k bug monitor. It is now an
5849 integer specifying a debug level (normally 0 or 1, but 2 means more
5850 debugging info for the mips target).
5852 * DEC Alpha native support
5854 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5855 debug info, but GDB works fairly well with the DEC compiler and should
5856 work with a future GCC release. See the README file for a few
5857 Alpha-specific notes.
5859 * Preliminary thread implementation
5861 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5863 * LynxOS native and target support for 386
5865 This release has been hosted on LynxOS 2.2, and also can be configured
5866 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5869 * Improvements in C++ mangling/demangling.
5871 This release has much better g++ debugging, specifically in name
5872 mangling/demangling, virtual function calls, print virtual table,
5873 call methods, ...etc.
5875 *** Changes in GDB-4.10:
5877 * User visible changes:
5879 Remote debugging using the GDB-specific (`target remote') protocol now
5880 supports the `load' command. This is only useful if you have some
5881 other way of getting the stub to the target system, and you can put it
5882 somewhere in memory where it won't get clobbered by the download.
5884 Filename completion now works.
5886 When run under emacs mode, the "info line" command now causes the
5887 arrow to point to the line specified. Also, "info line" prints
5888 addresses in symbolic form (as well as hex).
5890 All vxworks based targets now support a user settable option, called
5891 vxworks-timeout. This option represents the number of seconds gdb
5892 should wait for responses to rpc's. You might want to use this if
5893 your vxworks target is, perhaps, a slow software simulator or happens
5894 to be on the far side of a thin network line.
5898 This release contains support for using a DEC alpha as a GDB host for
5899 cross debugging. Native alpha debugging is not supported yet.
5902 *** Changes in GDB-4.9:
5906 This is the first GDB release which is accompanied by a matching testsuite.
5907 The testsuite requires installation of dejagnu, which should be available
5908 via ftp from most sites that carry GNU software.
5912 'Cfront' style demangling has had its name changed to 'ARM' style, to
5913 emphasize that it was written from the specifications in the C++ Annotated
5914 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5915 disclaimers, it still generated too much confusion with users attempting to
5916 use gdb with AT&T cfront.
5920 GDB now uses a standard remote interface to a simulator library.
5921 So far, the library contains simulators for the Zilog Z8001/2, the
5922 Hitachi H8/300, H8/500 and Super-H.
5924 * New targets supported
5926 H8/300 simulator h8300-hitachi-hms or h8300hms
5927 H8/500 simulator h8500-hitachi-hms or h8500hms
5928 SH simulator sh-hitachi-hms or sh
5929 Z8000 simulator z8k-zilog-none or z8ksim
5930 IDT MIPS board over serial line mips-idt-ecoff
5932 Cross-debugging to GO32 targets is supported. It requires a custom
5933 version of the i386-stub.c module which is integrated with the
5934 GO32 memory extender.
5936 * New remote protocols
5938 MIPS remote debugging protocol.
5940 * New source languages supported
5942 This version includes preliminary support for Chill, a Pascal like language
5943 used by telecommunications companies. Chill support is also being integrated
5944 into the GNU compiler, but we don't know when it will be publically available.
5947 *** Changes in GDB-4.8:
5949 * HP Precision Architecture supported
5951 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5952 version of this support was available as a set of patches from the
5953 University of Utah. GDB does not support debugging of programs
5954 compiled with the HP compiler, because HP will not document their file
5955 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5956 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5958 Many problems in the preliminary version have been fixed.
5960 * Faster and better demangling
5962 We have improved template demangling and fixed numerous bugs in the GNU style
5963 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5964 character types (wchar_t) are now supported. Demangling of each symbol is now
5965 only done once, and is cached when the symbol table for a file is read in.
5966 This results in a small increase in memory usage for C programs, a moderate
5967 increase in memory usage for C++ programs, and a fantastic speedup in
5970 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5971 from the specifications in the Annotated Reference Manual, which AT&T's
5972 compiler does not actually implement.
5974 * G++ multiple inheritance compiler problem
5976 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5977 inheritance lattices was reworked to properly discover ambiguities. We
5978 recently found an example which causes this new algorithm to fail in a
5979 very subtle way, producing bad debug information for those classes.
5980 The file 'gcc.patch' (in this directory) can be applied to gcc to
5981 circumvent the problem. A future GCC release will contain a complete
5984 The previous G++ debug info problem (mentioned below for the gdb-4.7
5985 release) is fixed in gcc version 2.3.2.
5987 * Improved configure script
5989 The `configure' script will now attempt to guess your system type if
5990 you don't supply a host system type. The old scheme of supplying a
5991 host system triplet is preferable over using this. All the magic is
5992 done in the new `config.guess' script. Examine it for details.
5994 We have also brought our configure script much more in line with the FSF's
5995 version. It now supports the --with-xxx options. In particular,
5996 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5997 The resulting GDB will not be able to read arbitrary object file formats --
5998 only the format ``expected'' to be used on the configured target system.
5999 We hope to make this the default in a future release.
6001 * Documentation improvements
6003 There's new internal documentation on how to modify GDB, and how to
6004 produce clean changes to the code. We implore people to read it
6005 before submitting changes.
6007 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6008 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6009 `info' files are also provided. To build `info' files from scratch,
6010 you will need the latest `makeinfo' release, which will be available in
6011 a future texinfo-X.Y release.
6013 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6014 We're not sure exactly which versions have this problem, but it has
6015 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6016 or better. If that isn't possible, there is a patch in
6017 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6018 around this problem.
6022 GDB now supports array constants that can be used in expressions typed in by
6023 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6024 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6027 The new directory `gdb/sparclite' contains a program that demonstrates
6028 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6030 * New native hosts supported
6032 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6033 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6035 * New targets supported
6037 AMD 29k family via UDI a29k-amd-udi or udi29k
6039 * New file formats supported
6041 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6042 HPUX core files, and SCO 3.2v2 core files.
6046 Attaching to processes now works again; thanks for the many bug reports.
6048 We have also stomped on a bunch of core dumps caused by
6049 printf_filtered("%s") problems.
6051 We eliminated a copyright problem on the rpc and ptrace header files
6052 for VxWorks, which was discovered at the last minute during the 4.7
6053 release. You should now be able to build a VxWorks GDB.
6055 You can now interrupt gdb while an attached process is running. This
6056 will cause the attached process to stop, and give control back to GDB.
6058 We fixed problems caused by using too many file descriptors
6059 for reading symbols from object files and libraries. This was
6060 especially a problem for programs that used many (~100) shared
6063 The `step' command now only enters a subroutine if there is line number
6064 information for the subroutine. Otherwise it acts like the `next'
6065 command. Previously, `step' would enter subroutines if there was
6066 any debugging information about the routine. This avoids problems
6067 when using `cc -g1' on MIPS machines.
6069 * Internal improvements
6071 GDB's internal interfaces have been improved to make it easier to support
6072 debugging of multiple languages in the future.
6074 GDB now uses a common structure for symbol information internally.
6075 Minimal symbols (derived from linkage symbols in object files), partial
6076 symbols (from a quick scan of debug information), and full symbols
6077 contain a common subset of information, making it easier to write
6078 shared code that handles any of them.
6080 * New command line options
6082 We now accept --silent as an alias for --quiet.
6086 The memory-mapped-malloc library is now licensed under the GNU Library
6087 General Public License.
6089 *** Changes in GDB-4.7:
6091 * Host/native/target split
6093 GDB has had some major internal surgery to untangle the support for
6094 hosts and remote targets. Now, when you configure GDB for a remote
6095 target, it will no longer load in all of the support for debugging
6096 local programs on the host. When fully completed and tested, this will
6097 ensure that arbitrary host/target combinations are possible.
6099 The primary conceptual shift is to separate the non-portable code in
6100 GDB into three categories. Host specific code is required any time GDB
6101 is compiled on that host, regardless of the target. Target specific
6102 code relates to the peculiarities of the target, but can be compiled on
6103 any host. Native specific code is everything else: it can only be
6104 built when the host and target are the same system. Child process
6105 handling and core file support are two common `native' examples.
6107 GDB's use of /proc for controlling Unix child processes is now cleaner.
6108 It has been split out into a single module under the `target_ops' vector,
6109 plus two native-dependent functions for each system that uses /proc.
6111 * New hosts supported
6113 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6114 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6115 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6117 * New targets supported
6119 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6120 68030 and CPU32 m68030-*-*, m68332-*-*
6122 * New native hosts supported
6124 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6125 (386bsd is not well tested yet)
6126 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6128 * New file formats supported
6130 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6131 supports reading of `a.out.adobe' object files, which are an a.out
6132 format extended with minimal information about multiple sections.
6136 `show copying' is the same as the old `info copying'.
6137 `show warranty' is the same as `info warrantee'.
6138 These were renamed for consistency. The old commands continue to work.
6140 `info handle' is a new alias for `info signals'.
6142 You can now define pre-command hooks, which attach arbitrary command
6143 scripts to any command. The commands in the hook will be executed
6144 prior to the user's command. You can also create a hook which will be
6145 executed whenever the program stops. See gdb.texinfo.
6149 We now deal with Cfront style name mangling, and can even extract type
6150 info from mangled symbols. GDB can automatically figure out which
6151 symbol mangling style your C++ compiler uses.
6153 Calling of methods and virtual functions has been improved as well.
6157 The crash that occured when debugging Sun Ansi-C compiled binaries is
6158 fixed. This was due to mishandling of the extra N_SO stabs output
6161 We also finally got Ultrix 4.2 running in house, and fixed core file
6162 support, with help from a dozen people on the net.
6164 John M. Farrell discovered that the reason that single-stepping was so
6165 slow on all of the Mips based platforms (primarily SGI and DEC) was
6166 that we were trying to demangle and lookup a symbol used for internal
6167 purposes on every instruction that was being stepped through. Changing
6168 the name of that symbol so that it couldn't be mistaken for a C++
6169 mangled symbol sped things up a great deal.
6171 Rich Pixley sped up symbol lookups in general by getting much smarter
6172 about when C++ symbol mangling is necessary. This should make symbol
6173 completion (TAB on the command line) much faster. It's not as fast as
6174 we'd like, but it's significantly faster than gdb-4.6.
6178 A new user controllable variable 'call_scratch_address' can
6179 specify the location of a scratch area to be used when GDB
6180 calls a function in the target. This is necessary because the
6181 usual method of putting the scratch area on the stack does not work
6182 in systems that have separate instruction and data spaces.
6184 We integrated changes to support the 29k UDI (Universal Debugger
6185 Interface), but discovered at the last minute that we didn't have all
6186 of the appropriate copyright paperwork. We are working with AMD to
6187 resolve this, and hope to have it available soon.
6191 We have sped up the remote serial line protocol, especially for targets
6192 with lots of registers. It now supports a new `expedited status' ('T')
6193 message which can be used in place of the existing 'S' status message.
6194 This allows the remote stub to send only the registers that GDB
6195 needs to make a quick decision about single-stepping or conditional
6196 breakpoints, eliminating the need to fetch the entire register set for
6197 each instruction being stepped through.
6199 The GDB remote serial protocol now implements a write-through cache for
6200 registers, only re-reading the registers if the target has run.
6202 There is also a new remote serial stub for SPARC processors. You can
6203 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6204 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6205 processor with a serial port.
6209 Configure.in files have become much easier to read and modify. A new
6210 `table driven' format makes it more obvious what configurations are
6211 supported, and what files each one uses.
6215 There is a new opcodes library which will eventually contain all of the
6216 disassembly routines and opcode tables. At present, it only contains
6217 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6218 disassembler (binutils/objdump) to share these routines.
6220 The libiberty library is now copylefted under the GNU Library General
6221 Public License. This allows more liberal use, and was done so libg++
6222 can use it. This makes no difference to GDB, since the Library License
6223 grants all the rights from the General Public License.
6227 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6228 reference to the stabs symbol info used by the debugger. It is (as far
6229 as we know) the only published document on this fascinating topic. We
6230 encourage you to read it, compare it to the stabs information on your
6231 system, and send improvements on the document in general (to
6232 bug-gdb@prep.ai.mit.edu).
6234 And, of course, many bugs have been fixed.
6237 *** Changes in GDB-4.6:
6239 * Better support for C++ function names
6241 GDB now accepts as input the "demangled form" of C++ overloaded function
6242 names and member function names, and can do command completion on such names
6243 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6244 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6245 Make use of command completion, it is your friend.
6247 GDB also now accepts a variety of C++ mangled symbol formats. They are
6248 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6249 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6250 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6251 for the list of formats.
6253 * G++ symbol mangling problem
6255 Recent versions of gcc have a bug in how they emit debugging information for
6256 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6257 directory) can be applied to gcc to fix the problem. Alternatively, if you
6258 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6259 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6260 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6263 * New 'maintenance' command
6265 All of the commands related to hacking GDB internals have been moved out of
6266 the main command set, and now live behind the 'maintenance' command. This
6267 can also be abbreviated as 'mt'. The following changes were made:
6269 dump-me -> maintenance dump-me
6270 info all-breakpoints -> maintenance info breakpoints
6271 printmsyms -> maintenance print msyms
6272 printobjfiles -> maintenance print objfiles
6273 printpsyms -> maintenance print psymbols
6274 printsyms -> maintenance print symbols
6276 The following commands are new:
6278 maintenance demangle Call internal GDB demangler routine to
6279 demangle a C++ link name and prints the result.
6280 maintenance print type Print a type chain for a given symbol
6282 * Change to .gdbinit file processing
6284 We now read the $HOME/.gdbinit file before processing the argv arguments
6285 (e.g. reading symbol files or core files). This allows global parameters to
6286 be set, which will apply during the symbol reading. The ./.gdbinit is still
6287 read after argv processing.
6289 * New hosts supported
6291 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6293 GNU/Linux support i386-unknown-linux or linux
6295 We are also including code to support the HP/PA running BSD and HPUX. This
6296 is almost guaranteed not to work, as we didn't have time to test or build it
6297 for this release. We are including it so that the more adventurous (or
6298 masochistic) of you can play with it. We also had major problems with the
6299 fact that the compiler that we got from HP doesn't support the -g option.
6302 * New targets supported
6304 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6306 * More smarts about finding #include files
6308 GDB now remembers the compilation directory for all include files, and for
6309 all files from which C is generated (like yacc and lex sources). This
6310 greatly improves GDB's ability to find yacc/lex sources, and include files,
6311 especially if you are debugging your program from a directory different from
6312 the one that contains your sources.
6314 We also fixed a bug which caused difficulty with listing and setting
6315 breakpoints in include files which contain C code. (In the past, you had to
6316 try twice in order to list an include file that you hadn't looked at before.)
6318 * Interesting infernals change
6320 GDB now deals with arbitrary numbers of sections, where the symbols for each
6321 section must be relocated relative to that section's landing place in the
6322 target's address space. This work was needed to support ELF with embedded
6323 stabs used by Solaris-2.0.
6325 * Bug fixes (of course!)
6327 There have been loads of fixes for the following things:
6328 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6329 i960, stabs, DOS(GO32), procfs, etc...
6331 See the ChangeLog for details.
6333 *** Changes in GDB-4.5:
6335 * New machines supported (host and target)
6337 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6339 SGI Irix-4.x mips-sgi-irix4 or iris4
6341 * New malloc package
6343 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6344 Mmalloc is capable of handling mutiple heaps of memory. It is also
6345 capable of saving a heap to a file, and then mapping it back in later.
6346 This can be used to greatly speedup the startup of GDB by using a
6347 pre-parsed symbol table which lives in a mmalloc managed heap. For
6348 more details, please read mmalloc/mmalloc.texi.
6352 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6353 'help info proc' for details.
6355 * MIPS ecoff symbol table format
6357 The code that reads MIPS symbol table format is now supported on all hosts.
6358 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6361 * File name changes for MS-DOS
6363 Many files in the config directories have been renamed to make it easier to
6364 support GDB on MS-DOSe systems (which have very restrictive file name
6365 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6366 environment) is close to working but has some remaining problems. Note
6367 that debugging of DOS programs is not supported, due to limitations
6368 in the ``operating system'', but it can be used to host cross-debugging.
6370 * Cross byte order fixes
6372 Many fixes have been made to support cross debugging of Sparc and MIPS
6373 targets from hosts whose byte order differs.
6375 * New -mapped and -readnow options
6377 If memory-mapped files are available on your system through the 'mmap'
6378 system call, you can use the -mapped option on the `file' or
6379 `symbol-file' commands to cause GDB to write the symbols from your
6380 program into a reusable file. If the program you are debugging is
6381 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6382 Future GDB debugging sessions will notice the presence of this file,
6383 and will quickly map in symbol information from it, rather than reading
6384 the symbol table from the executable program. Using the '-mapped'
6385 option in a GDB `file' or `symbol-file' command has the same effect as
6386 starting GDB with the '-mapped' command-line option.
6388 You can cause GDB to read the entire symbol table immediately by using
6389 the '-readnow' option with any of the commands that load symbol table
6390 information (or on the GDB command line). This makes the command
6391 slower, but makes future operations faster.
6393 The -mapped and -readnow options are typically combined in order to
6394 build a `fred.syms' file that contains complete symbol information.
6395 A simple GDB invocation to do nothing but build a `.syms' file for future
6398 gdb -batch -nx -mapped -readnow programname
6400 The `.syms' file is specific to the host machine on which GDB is run.
6401 It holds an exact image of GDB's internal symbol table. It cannot be
6402 shared across multiple host platforms.
6404 * longjmp() handling
6406 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6407 siglongjmp() without losing control. This feature has not yet been ported to
6408 all systems. It currently works on many 386 platforms, all MIPS-based
6409 platforms (SGI, DECstation, etc), and Sun3/4.
6413 Preliminary work has been put in to support the new Solaris OS from Sun. At
6414 this time, it can control and debug processes, but it is not capable of
6419 As always, many many bug fixes. The major areas were with g++, and mipsread.
6420 People using the MIPS-based platforms should experience fewer mysterious
6421 crashes and trashed symbol tables.
6423 *** Changes in GDB-4.4:
6425 * New machines supported (host and target)
6427 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6429 BSD Reno on Vax vax-dec-bsd
6430 Ultrix on Vax vax-dec-ultrix
6432 * New machines supported (target)
6434 AMD 29000 embedded, using EBMON a29k-none-none
6438 GDB continues to improve its handling of C++. `References' work better.
6439 The demangler has also been improved, and now deals with symbols mangled as
6440 per the Annotated C++ Reference Guide.
6442 GDB also now handles `stabs' symbol information embedded in MIPS
6443 `ecoff' symbol tables. Since the ecoff format was not easily
6444 extensible to handle new languages such as C++, this appeared to be a
6445 good way to put C++ debugging info into MIPS binaries. This option
6446 will be supported in the GNU C compiler, version 2, when it is
6449 * New features for SVR4
6451 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6452 shared libraries. Debugging dynamically linked programs should present
6453 only minor differences from debugging statically linked programs.
6455 The `info proc' command will print out information about any process
6456 on an SVR4 system (including the one you are debugging). At the moment,
6457 it prints the address mappings of the process.
6459 If you bring up GDB on another SVR4 system, please send mail to
6460 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6462 * Better dynamic linking support in SunOS
6464 Reading symbols from shared libraries which contain debugging symbols
6465 now works properly. However, there remain issues such as automatic
6466 skipping of `transfer vector' code during function calls, which
6467 make it harder to debug code in a shared library, than to debug the
6468 same code linked statically.
6472 GDB is now using the latest `getopt' routines from the FSF. This
6473 version accepts the -- prefix for options with long names. GDB will
6474 continue to accept the old forms (-option and +option) as well.
6475 Various single letter abbreviations for options have been explicity
6476 added to the option table so that they won't get overshadowed in the
6477 future by other options that begin with the same letter.
6481 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6482 Many assorted bugs have been handled. Many more remain to be handled.
6483 See the various ChangeLog files (primarily in gdb and bfd) for details.
6486 *** Changes in GDB-4.3:
6488 * New machines supported (host and target)
6490 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6491 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6492 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6494 * Almost SCO Unix support
6496 We had hoped to support:
6497 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6498 (except for core file support), but we discovered very late in the release
6499 that it has problems with process groups that render gdb unusable. Sorry
6500 about that. I encourage people to fix it and post the fixes.
6502 * Preliminary ELF and DWARF support
6504 GDB can read ELF object files on System V Release 4, and can handle
6505 debugging records for C, in DWARF format, in ELF files. This support
6506 is preliminary. If you bring up GDB on another SVR4 system, please
6507 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6512 GDB now uses the latest `readline' library. One user-visible change
6513 is that two tabs will list possible command completions, which previously
6514 required typing M-? (meta-question mark, or ESC ?).
6518 The `stepi' bug that many of you noticed has been squashed.
6519 Many bugs in C++ have been handled. Many more remain to be handled.
6520 See the various ChangeLog files (primarily in gdb and bfd) for details.
6522 * State of the MIPS world (in case you wondered):
6524 GDB can understand the symbol tables emitted by the compilers
6525 supplied by most vendors of MIPS-based machines, including DEC. These
6526 symbol tables are in a format that essentially nobody else uses.
6528 Some versions of gcc come with an assembler post-processor called
6529 mips-tfile. This program is required if you want to do source-level
6530 debugging of gcc-compiled programs. I believe FSF does not ship
6531 mips-tfile with gcc version 1, but it will eventually come with gcc
6534 Debugging of g++ output remains a problem. g++ version 1.xx does not
6535 really support it at all. (If you're lucky, you should be able to get
6536 line numbers and stack traces to work, but no parameters or local
6537 variables.) With some work it should be possible to improve the
6540 When gcc version 2 is released, you will have somewhat better luck.
6541 However, even then you will get confusing results for inheritance and
6544 We will eventually provide full debugging of g++ output on
6545 DECstations. This will probably involve some kind of stabs-in-ecoff
6546 encapulation, but the details have not been worked out yet.
6549 *** Changes in GDB-4.2:
6551 * Improved configuration
6553 Only one copy of `configure' exists now, and it is not self-modifying.
6554 Porting BFD is simpler.
6558 The `step' and `next' commands now only stop at the first instruction
6559 of a source line. This prevents the multiple stops that used to occur
6560 in switch statements, for-loops, etc. `Step' continues to stop if a
6561 function that has debugging information is called within the line.
6565 Lots of small bugs fixed. More remain.
6567 * New host supported (not target)
6569 Intel 386 PC clone running Mach i386-none-mach
6572 *** Changes in GDB-4.1:
6574 * Multiple source language support
6576 GDB now has internal scaffolding to handle several source languages.
6577 It determines the type of each source file from its filename extension,
6578 and will switch expression parsing and number formatting to match the
6579 language of the function in the currently selected stack frame.
6580 You can also specifically set the language to be used, with
6581 `set language c' or `set language modula-2'.
6585 GDB now has preliminary support for the GNU Modula-2 compiler,
6586 currently under development at the State University of New York at
6587 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6588 continue through the fall of 1991 and into 1992.
6590 Other Modula-2 compilers are currently not supported, and attempting to
6591 debug programs compiled with them will likely result in an error as the
6592 symbol table is read. Feel free to work on it, though!
6594 There are hooks in GDB for strict type checking and range checking,
6595 in the `Modula-2 philosophy', but they do not currently work.
6599 GDB can now write to executable and core files (e.g. patch
6600 a variable's value). You must turn this switch on, specify
6601 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6602 by assigning a new value to a variable. Modifications take
6605 * Automatic SunOS shared library reading
6607 When you run your program, GDB automatically determines where its
6608 shared libraries (if any) have been loaded, and reads their symbols.
6609 The `share' command is no longer needed. This also works when
6610 examining core files.
6614 You can specify the number of lines that the `list' command shows.
6617 * New machines supported (host and target)
6619 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6620 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6621 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6623 * New hosts supported (not targets)
6625 IBM RT/PC: romp-ibm-aix or rtpc
6627 * New targets supported (not hosts)
6629 AMD 29000 embedded with COFF a29k-none-coff
6630 AMD 29000 embedded with a.out a29k-none-aout
6631 Ultracomputer remote kernel debug a29k-nyu-kern
6633 * New remote interfaces
6639 *** Changes in GDB-4.0:
6643 Wide output is wrapped at good places to make the output more readable.
6645 Gdb now supports cross-debugging from a host machine of one type to a
6646 target machine of another type. Communication with the target system
6647 is over serial lines. The ``target'' command handles connecting to the
6648 remote system; the ``load'' command will download a program into the
6649 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6650 also supports debugging of realtime processes running under VxWorks,
6651 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6652 stub on the target system.
6654 New CPUs supported include the AMD 29000 and Intel 960.
6656 GDB now reads object files and symbol tables via a ``binary file''
6657 library, which allows a single copy of GDB to debug programs of multiple
6658 object file types such as a.out and coff.
6660 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6661 refcard.dvi and refcard.ps are available to format it).
6664 * Control-Variable user interface simplified
6666 All variables that control the operation of the debugger can be set
6667 by the ``set'' command, and displayed by the ``show'' command.
6669 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6670 ``Show prompt'' produces the response:
6671 Gdb's prompt is new-gdb=>.
6673 What follows are the NEW set commands. The command ``help set'' will
6674 print a complete list of old and new set commands. ``help set FOO''
6675 will give a longer description of the variable FOO. ``show'' will show
6676 all of the variable descriptions and their current settings.
6678 confirm on/off: Enables warning questions for operations that are
6679 hard to recover from, e.g. rerunning the program while
6680 it is already running. Default is ON.
6682 editing on/off: Enables EMACS style command line editing
6683 of input. Previous lines can be recalled with
6684 control-P, the current line can be edited with control-B,
6685 you can search for commands with control-R, etc.
6688 history filename NAME: NAME is where the gdb command history
6689 will be stored. The default is .gdb_history,
6690 or the value of the environment variable
6693 history size N: The size, in commands, of the command history. The
6694 default is 256, or the value of the environment variable
6697 history save on/off: If this value is set to ON, the history file will
6698 be saved after exiting gdb. If set to OFF, the
6699 file will not be saved. The default is OFF.
6701 history expansion on/off: If this value is set to ON, then csh-like
6702 history expansion will be performed on
6703 command line input. The default is OFF.
6705 radix N: Sets the default radix for input and output. It can be set
6706 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6707 in the current radix, so "set radix 10" is always a no-op.
6709 height N: This integer value is the number of lines on a page. Default
6710 is 24, the current `stty rows'' setting, or the ``li#''
6711 setting from the termcap entry matching the environment
6714 width N: This integer value is the number of characters on a line.
6715 Default is 80, the current `stty cols'' setting, or the ``co#''
6716 setting from the termcap entry matching the environment
6719 Note: ``set screensize'' is obsolete. Use ``set height'' and
6720 ``set width'' instead.
6722 print address on/off: Print memory addresses in various command displays,
6723 such as stack traces and structure values. Gdb looks
6724 more ``symbolic'' if you turn this off; it looks more
6725 ``machine level'' with it on. Default is ON.
6727 print array on/off: Prettyprint arrays. New convenient format! Default
6730 print demangle on/off: Print C++ symbols in "source" form if on,
6733 print asm-demangle on/off: Same, for assembler level printouts
6736 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6739 * Support for Epoch Environment.
6741 The epoch environment is a version of Emacs v18 with windowing. One
6742 new command, ``inspect'', is identical to ``print'', except that if you
6743 are running in the epoch environment, the value is printed in its own
6747 * Support for Shared Libraries
6749 GDB can now debug programs and core files that use SunOS shared libraries.
6750 Symbols from a shared library cannot be referenced
6751 before the shared library has been linked with the program (this
6752 happens after you type ``run'' and before the function main() is entered).
6753 At any time after this linking (including when examining core files
6754 from dynamically linked programs), gdb reads the symbols from each
6755 shared library when you type the ``sharedlibrary'' command.
6756 It can be abbreviated ``share''.
6758 sharedlibrary REGEXP: Load shared object library symbols for files
6759 matching a unix regular expression. No argument
6760 indicates to load symbols for all shared libraries.
6762 info sharedlibrary: Status of loaded shared libraries.
6767 A watchpoint stops execution of a program whenever the value of an
6768 expression changes. Checking for this slows down execution
6769 tremendously whenever you are in the scope of the expression, but is
6770 quite useful for catching tough ``bit-spreader'' or pointer misuse
6771 problems. Some machines such as the 386 have hardware for doing this
6772 more quickly, and future versions of gdb will use this hardware.
6774 watch EXP: Set a watchpoint (breakpoint) for an expression.
6776 info watchpoints: Information about your watchpoints.
6778 delete N: Deletes watchpoint number N (same as breakpoints).
6779 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6780 enable N: Re-enables watchpoint number N (same as breakpoints).
6783 * C++ multiple inheritance
6785 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6788 * C++ exception handling
6790 Gdb now supports limited C++ exception handling. Besides the existing
6791 ability to breakpoint on an exception handler, gdb can breakpoint on
6792 the raising of an exception (before the stack is peeled back to the
6795 catch FOO: If there is a FOO exception handler in the dynamic scope,
6796 set a breakpoint to catch exceptions which may be raised there.
6797 Multiple exceptions (``catch foo bar baz'') may be caught.
6799 info catch: Lists all exceptions which may be caught in the
6800 current stack frame.
6803 * Minor command changes
6805 The command ``call func (arg, arg, ...)'' now acts like the print
6806 command, except it does not print or save a value if the function's result
6807 is void. This is similar to dbx usage.
6809 The ``up'' and ``down'' commands now always print the frame they end up
6810 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6811 frames without printing.
6813 * New directory command
6815 'dir' now adds directories to the FRONT of the source search path.
6816 The path starts off empty. Source files that contain debug information
6817 about the directory in which they were compiled can be found even
6818 with an empty path; Sun CC and GCC include this information. If GDB can't
6819 find your source file in the current directory, type "dir .".
6821 * Configuring GDB for compilation
6823 For normal use, type ``./configure host''. See README or gdb.texinfo
6826 GDB now handles cross debugging. If you are remotely debugging between
6827 two different machines, type ``./configure host -target=targ''.
6828 Host is the machine where GDB will run; targ is the machine
6829 where the program that you are debugging will run.