1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now uses the GNU MPFR library, if available, to emulate target
7 floating-point arithmetic during expression evaluation when the target
8 uses different floating-point formats than the host. At least version
9 3.1 of GNU MPFR is required.
11 * GDB now supports access to the guarded-storage-control registers and the
12 software-based guarded-storage broadcast control registers on IBM z14.
14 * On Unix systems, GDB now supports transmitting environment variables
15 that are to be set or unset to GDBserver. These variables will
16 affect the environment to be passed to the remote inferior.
18 To inform GDB of environment variables that are to be transmitted to
19 GDBserver, use the "set environment" command. Only user set
20 environment variables are sent to GDBserver.
22 To inform GDB of environment variables that are to be unset before
23 the remote inferior is started by the GDBserver, use the "unset
26 * Completion improvements
28 ** GDB can now complete function parameters in linespecs and
29 explicit locations without quoting. When setting breakpoints,
30 quoting around functions names to help with TAB-completion is
31 generally no longer necessary. For example, this now completes
34 (gdb) b function(in[TAB]
37 Related, GDB is no longer confused with completing functions in
38 C++ anonymous namespaces:
41 (gdb) b (anonymous namespace)::[TAB][TAB]
42 (anonymous namespace)::a_function()
43 (anonymous namespace)::b_function()
45 ** GDB now has much improved linespec and explicit locations TAB
46 completion support, that better understands what you're
47 completing and offers better suggestions. For example, GDB no
48 longer offers data symbols as possible completions when you're
51 ** GDB now TAB-completes label symbol names.
53 ** The "complete" command now mimics TAB completion accurately.
57 ** New events gdb.new_inferior, gdb.inferior_deleted, and
58 gdb.new_thread are emitted. See the manual for further
61 ** A new command, "rbreak" has been added to the Python API. This
62 command allows the setting of a large number of breakpoints via a
63 regex pattern in Python. See the manual for further details.
65 * New features in the GDB remote stub, GDBserver
67 ** GDBserver is now able to start inferior processes with a
68 specified initial working directory.
70 The user can set the desired working directory to be used from
71 GDB using the new "set cwd" command.
73 ** New "--selftest" command line option runs some GDBserver self
74 tests. These self tests are disabled in releases.
76 ** On Unix systems, GDBserver now does globbing expansion and variable
77 substitution in inferior command line arguments.
79 This is done by starting inferiors using a shell, like GDB does.
80 See "set startup-with-shell" in the user manual for how to disable
81 this from GDB when using "target extended-remote". When using
82 "target remote", you can disable the startup with shell by using the
83 new "--no-startup-with-shell" GDBserver command line option.
85 ** On Unix systems, GDBserver now supports receiving environment
86 variables that are to be set or unset from GDB. These variables
87 will affect the environment to be passed to the inferior.
89 * When catching an Ada exception raised with a message, GDB now prints
90 the message in the catchpoint hit notification. In GDB/MI mode, that
91 information is provided as an extra field named "exception-message"
92 in the *stopped notification.
96 QEnvironmentHexEncoded
97 Inform GDBserver of an environment variable that is to be passed to
98 the inferior when starting it.
101 Inform GDBserver of an environment variable that is to be unset
102 before starting the remote inferior.
105 Inform GDBserver that the environment should be reset (i.e.,
106 user-set environment variables should be unset).
109 Indicates whether the inferior must be started with a shell or not.
112 Tell GDBserver that the inferior to be started should use a specific
115 * The "maintenance print c-tdesc" command now takes an optional
116 argument which is the file name of XML target description.
118 * The "maintenance selftest" command now takes an optional argument to
119 filter the tests to be run.
121 * The "enable", and "disable" commands now accept a range of
122 breakpoint locations, e.g. "enable 1.3-5".
127 Set and show the current working directory for the inferior.
130 Set and show compilation command used for compiling and injecting code
131 with the 'compile' commands.
133 set debug separate-debug-file
134 show debug separate-debug-file
135 Control the display of debug output about separate debug file search.
138 List the registered selftests.
141 Start the debugged program stopping at the first instruction.
143 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
146 * Safer/improved support for debugging with no debug info
148 GDB no longer assumes functions with no debug information return
151 This means that GDB now refuses to call such functions unless you
152 tell it the function's type, by either casting the call to the
153 declared return type, or by casting the function to a function
154 pointer of the right type, and calling that:
156 (gdb) p getenv ("PATH")
157 'getenv' has unknown return type; cast the call to its declared return type
158 (gdb) p (char *) getenv ("PATH")
159 $1 = 0x7fffffffe "/usr/local/bin:/"...
160 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
161 $2 = 0x7fffffffe "/usr/local/bin:/"...
163 Similarly, GDB no longer assumes that global variables with no debug
164 info have type 'int', and refuses to print the variable's value
165 unless you tell it the variable's type:
168 'var' has unknown type; cast it to its declared type
172 * New native configurations
174 FreeBSD/aarch64 aarch64*-*-freebsd*
175 FreeBSD/arm arm*-*-freebsd*
179 FreeBSD/aarch64 aarch64*-*-freebsd*
180 FreeBSD/arm arm*-*-freebsd*
182 * Removed targets and native configurations
184 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
186 *** Changes in GDB 8.0
188 * GDB now supports access to the PKU register on GNU/Linux. The register is
189 added by the Memory Protection Keys for Userspace feature which will be
190 available in future Intel CPUs.
192 * GDB now supports C++11 rvalue references.
196 ** New functions to start, stop and access a running btrace recording.
197 ** Rvalue references are now supported in gdb.Type.
199 * GDB now supports recording and replaying rdrand and rdseed Intel 64
202 * Building GDB and GDBserver now requires a C++11 compiler.
204 For example, GCC 4.8 or later.
206 It is no longer possible to build GDB or GDBserver with a C
207 compiler. The --disable-build-with-cxx configure option has been
210 * Building GDB and GDBserver now requires GNU make >= 3.81.
212 It is no longer supported to build GDB or GDBserver with another
213 implementation of the make program or an earlier version of GNU make.
215 * Native debugging on MS-Windows supports command-line redirection
217 Command-line arguments used for starting programs on MS-Windows can
218 now include redirection symbols supported by native Windows shells,
219 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
220 as "run", "start", and "set args", as well as the corresponding MI
223 * Support for thread names on MS-Windows.
225 GDB now catches and handles the special exception that programs
226 running on MS-Windows use to assign names to threads in the
229 * Support for Java programs compiled with gcj has been removed.
231 * User commands now accept an unlimited number of arguments.
232 Previously, only up to 10 was accepted.
234 * The "eval" command now expands user-defined command arguments.
236 This makes it easier to process a variable number of arguments:
241 eval "print $arg%d", $i
246 * Target descriptions can now describe registers for sparc32 and sparc64.
248 * GDB now supports DWARF version 5 (debug information format).
249 Its .debug_names index is not yet supported.
251 * New native configurations
253 FreeBSD/mips mips*-*-freebsd
257 Synopsys ARC arc*-*-elf32
258 FreeBSD/mips mips*-*-freebsd
260 * Removed targets and native configurations
262 Alpha running FreeBSD alpha*-*-freebsd*
263 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
268 Erases all the flash memory regions reported by the target.
270 maint print arc arc-instruction address
271 Print internal disassembler information about instruction at a given address.
275 set disassembler-options
276 show disassembler-options
277 Controls the passing of target specific information to the disassembler.
278 If it is necessary to specify more than one disassembler option then
279 multiple options can be placed together into a comma separated list.
280 The default value is the empty string. Currently, the only supported
281 targets are ARM, PowerPC and S/390.
286 Erases all the flash memory regions reported by the target. This is
287 equivalent to the CLI command flash-erase.
289 -file-list-shared-libraries
290 List the shared libraries in the program. This is
291 equivalent to the CLI command "info shared".
293 *** Changes in GDB 7.12
295 * GDB and GDBserver now build with a C++ compiler by default.
297 The --enable-build-with-cxx configure option is now enabled by
298 default. One must now explicitly configure with
299 --disable-build-with-cxx in order to build with a C compiler. This
300 option will be removed in a future release.
302 * GDBserver now supports recording btrace without maintaining an active
305 * GDB now supports a negative repeat count in the 'x' command to examine
306 memory backward from the given address. For example:
309 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
310 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
311 (gdb) x/-5i 0x0000000000400580
312 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
313 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
314 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
315 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
316 0x40057b <main(int, char**)+25>:
317 callq 0x400536 <Func1(int, char const*)>
319 * Fortran: Support structures with fields of dynamic types and
320 arrays of dynamic types.
322 * The symbol dumping maintenance commands have new syntax.
323 maint print symbols [-pc address] [--] [filename]
324 maint print symbols [-objfile objfile] [-source source] [--] [filename]
325 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
326 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
327 maint print msymbols [-objfile objfile] [--] [filename]
329 * GDB now supports multibit bitfields and enums in target register
332 * New Python-based convenience function $_as_string(val), which returns
333 the textual representation of a value. This function is especially
334 useful to obtain the text label of an enum value.
336 * Intel MPX bound violation handling.
338 Segmentation faults caused by a Intel MPX boundary violation
339 now display the kind of violation (upper or lower), the memory
340 address accessed and the memory bounds, along with the usual
341 signal received and code location.
345 Program received signal SIGSEGV, Segmentation fault
346 Upper bound violation while accessing address 0x7fffffffc3b3
347 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
348 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
350 * Rust language support.
351 GDB now supports debugging programs written in the Rust programming
352 language. See https://www.rust-lang.org/ for more information about
355 * Support for running interpreters on specified input/output devices
357 GDB now supports a new mechanism that allows frontends to provide
358 fully featured GDB console views, as a better alternative to
359 building such views on top of the "-interpreter-exec console"
360 command. See the new "new-ui" command below. With that command,
361 frontends can now start GDB in the traditional command-line mode
362 running in an embedded terminal emulator widget, and create a
363 separate MI interpreter running on a specified i/o device. In this
364 way, GDB handles line editing, history, tab completion, etc. in the
365 console all by itself, and the GUI uses the separate MI interpreter
366 for its own control and synchronization, invisible to the command
369 * The "catch syscall" command catches groups of related syscalls.
371 The "catch syscall" command now supports catching a group of related
372 syscalls using the 'group:' or 'g:' prefix.
377 skip -gfile file-glob-pattern
378 skip -function function
379 skip -rfunction regular-expression
380 A generalized form of the skip command, with new support for
381 glob-style file names and regular expressions for function names.
382 Additionally, a file spec and a function spec may now be combined.
384 maint info line-table REGEXP
385 Display the contents of GDB's internal line table data struture.
388 Run any GDB unit tests that were compiled in.
391 Start a new user interface instance running INTERP as interpreter,
392 using the TTY file for input/output.
396 ** gdb.Breakpoint objects have a new attribute "pending", which
397 indicates whether the breakpoint is pending.
398 ** Three new breakpoint-related events have been added:
399 gdb.breakpoint_created, gdb.breakpoint_modified, and
400 gdb.breakpoint_deleted.
403 Signal ("set") the given MS-Windows event object. This is used in
404 conjunction with the Windows JIT debugging (AeDebug) support, where
405 the OS suspends a crashing process until a debugger can attach to
406 it. Resuming the crashing process, in order to debug it, is done by
409 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
410 was added in GDBserver, including JIT compiling fast tracepoint's
411 conditional expression bytecode into native code.
413 * Support for various remote target protocols and ROM monitors has
416 target m32rsdi Remote M32R debugging over SDI
417 target mips MIPS remote debugging protocol
418 target pmon PMON ROM monitor
419 target ddb NEC's DDB variant of PMON for Vr4300
420 target rockhopper NEC RockHopper variant of PMON
421 target lsi LSI variant of PMO
423 * Support for tracepoints and fast tracepoints on powerpc-linux,
424 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
425 including JIT compiling fast tracepoint's conditional expression
426 bytecode into native code.
428 * MI async record =record-started now includes the method and format used for
429 recording. For example:
431 =record-started,thread-group="i1",method="btrace",format="bts"
433 * MI async record =thread-selected now includes the frame field. For example:
435 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
439 Andes NDS32 nds32*-*-elf
441 *** Changes in GDB 7.11
443 * GDB now supports debugging kernel-based threads on FreeBSD.
445 * Per-inferior thread numbers
447 Thread numbers are now per inferior instead of global. If you're
448 debugging multiple inferiors, GDB displays thread IDs using a
449 qualified INF_NUM.THR_NUM form. For example:
453 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
454 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
455 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
456 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
458 As consequence, thread numbers as visible in the $_thread
459 convenience variable and in Python's InferiorThread.num attribute
460 are no longer unique between inferiors.
462 GDB now maintains a second thread ID per thread, referred to as the
463 global thread ID, which is the new equivalent of thread numbers in
464 previous releases. See also $_gthread below.
466 For backwards compatibility, MI's thread IDs always refer to global
469 * Commands that accept thread IDs now accept the qualified
470 INF_NUM.THR_NUM form as well. For example:
473 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
476 * In commands that accept a list of thread IDs, you can now refer to
477 all threads of an inferior using a star wildcard. GDB accepts
478 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
479 refer to all threads of the current inferior. For example, "info
482 * You can use "info threads -gid" to display the global thread ID of
485 * The new convenience variable $_gthread holds the global number of
488 * The new convenience variable $_inferior holds the number of the
491 * GDB now displays the ID and name of the thread that hit a breakpoint
492 or received a signal, if your program is multi-threaded. For
495 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
496 Thread 1 "main" received signal SIGINT, Interrupt.
498 * Record btrace now supports non-stop mode.
500 * Support for tracepoints on aarch64-linux was added in GDBserver.
502 * The 'record instruction-history' command now indicates speculative execution
503 when using the Intel Processor Trace recording format.
505 * GDB now allows users to specify explicit locations, bypassing
506 the linespec parser. This feature is also available to GDB/MI
509 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
510 GDB now is able to debug both AArch64 applications and ARM applications
513 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
514 including JIT compiling fast tracepoint's conditional expression bytecode
517 * GDB now supports displaced stepping on AArch64 GNU/Linux.
519 * "info threads", "info inferiors", "info display", "info checkpoints"
520 and "maint info program-spaces" now list the corresponding items in
521 ascending ID order, for consistency with all other "info" commands.
523 * In Ada, the overloads selection menu has been enhanced to display the
524 parameter types and the return types for the matching overloaded subprograms.
528 maint set target-non-stop (on|off|auto)
529 maint show target-non-stop
530 Control whether GDB targets always operate in non-stop mode even if
531 "set non-stop" is "off". The default is "auto", meaning non-stop
532 mode is enabled if supported by the target.
534 maint set bfd-sharing
535 maint show bfd-sharing
536 Control the reuse of bfd objects.
540 Control display of debugging info regarding bfd caching.
544 Control display of debugging info regarding FreeBSD threads.
546 set remote multiprocess-extensions-packet
547 show remote multiprocess-extensions-packet
548 Set/show the use of the remote protocol multiprocess extensions.
550 set remote thread-events
551 show remote thread-events
552 Set/show the use of thread create/exit events.
554 set ada print-signatures on|off
555 show ada print-signatures"
556 Control whether parameter types and return types are displayed in overloads
557 selection menus. It is activaled (@code{on}) by default.
561 Controls the maximum size of memory, in bytes, that GDB will
562 allocate for value contents. Prevents incorrect programs from
563 causing GDB to allocate overly large buffers. Default is 64k.
565 * The "disassemble" command accepts a new modifier: /s.
566 It prints mixed source+disassembly like /m with two differences:
567 - disassembled instructions are now printed in program order, and
568 - and source for all relevant files is now printed.
569 The "/m" option is now considered deprecated: its "source-centric"
570 output hasn't proved useful in practice.
572 * The "record instruction-history" command accepts a new modifier: /s.
573 It behaves exactly like /m and prints mixed source+disassembly.
575 * The "set scheduler-locking" command supports a new mode "replay".
576 It behaves like "off" in record mode and like "on" in replay mode.
578 * Support for various ROM monitors has been removed:
580 target dbug dBUG ROM monitor for Motorola ColdFire
581 target picobug Motorola picobug monitor
582 target dink32 DINK32 ROM monitor for PowerPC
583 target m32r Renesas M32R/D ROM monitor
584 target mon2000 mon2000 ROM monitor
585 target ppcbug PPCBUG ROM monitor for PowerPC
587 * Support for reading/writing memory and extracting values on architectures
588 whose memory is addressable in units of any integral multiple of 8 bits.
593 Indicates that an exec system call was executed.
595 exec-events feature in qSupported
596 The qSupported packet allows GDB to request support for exec
597 events using the new 'gdbfeature' exec-event, and the qSupported
598 response can contain the corresponding 'stubfeature'. Set and
599 show commands can be used to display whether these features are enabled.
602 Equivalent to interrupting with the ^C character, but works in
605 thread created stop reason (T05 create:...)
606 Indicates that the thread was just created and is stopped at entry.
608 thread exit stop reply (w exitcode;tid)
609 Indicates that the thread has terminated.
612 Enables/disables thread create and exit event reporting. For
613 example, this is used in non-stop mode when GDB stops a set of
614 threads and synchronously waits for the their corresponding stop
615 replies. Without exit events, if one of the threads exits, GDB
616 would hang forever not knowing that it should no longer expect a
617 stop for that same thread.
620 Indicates that there are no resumed threads left in the target (all
621 threads are stopped). The remote stub reports support for this stop
622 reply to GDB's qSupported query.
625 Enables/disables catching syscalls from the inferior process.
626 The remote stub reports support for this packet to GDB's qSupported query.
628 syscall_entry stop reason
629 Indicates that a syscall was just called.
631 syscall_return stop reason
632 Indicates that a syscall just returned.
634 * Extended-remote exec events
636 ** GDB now has support for exec events on extended-remote Linux targets.
637 For such targets with Linux kernels 2.5.46 and later, this enables
638 follow-exec-mode and exec catchpoints.
640 set remote exec-event-feature-packet
641 show remote exec-event-feature-packet
642 Set/show the use of the remote exec event feature.
644 * Thread names in remote protocol
646 The reply to qXfer:threads:read may now include a name attribute for each
649 * Target remote mode fork and exec events
651 ** GDB now has support for fork and exec events on target remote mode
652 Linux targets. For such targets with Linux kernels 2.5.46 and later,
653 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
654 fork and exec catchpoints.
656 * Remote syscall events
658 ** GDB now has support for catch syscall on remote Linux targets,
659 currently enabled on x86/x86_64 architectures.
661 set remote catch-syscall-packet
662 show remote catch-syscall-packet
663 Set/show the use of the remote catch syscall feature.
667 ** The -var-set-format command now accepts the zero-hexadecimal
668 format. It outputs data in hexadecimal format with zero-padding on the
673 ** gdb.InferiorThread objects have a new attribute "global_num",
674 which refers to the thread's global thread ID. The existing
675 "num" attribute now refers to the thread's per-inferior number.
676 See "Per-inferior thread numbers" above.
677 ** gdb.InferiorThread objects have a new attribute "inferior", which
678 is the Inferior object the thread belongs to.
680 *** Changes in GDB 7.10
682 * Support for process record-replay and reverse debugging on aarch64*-linux*
683 targets has been added. GDB now supports recording of A64 instruction set
684 including advance SIMD instructions.
686 * Support for Sun's version of the "stabs" debug file format has been removed.
688 * GDB now honors the content of the file /proc/PID/coredump_filter
689 (PID is the process ID) on GNU/Linux systems. This file can be used
690 to specify the types of memory mappings that will be included in a
691 corefile. For more information, please refer to the manual page of
692 "core(5)". GDB also has a new command: "set use-coredump-filter
693 on|off". It allows to set whether GDB will read the content of the
694 /proc/PID/coredump_filter file when generating a corefile.
696 * The "info os" command on GNU/Linux can now display information on
698 "info os cpus" Listing of all cpus/cores on the system
700 * GDB has two new commands: "set serial parity odd|even|none" and
701 "show serial parity". These allows to set or show parity for the
704 * The "info source" command now displays the producer string if it was
705 present in the debug info. This typically includes the compiler version
706 and may include things like its command line arguments.
708 * The "info dll", an alias of the "info sharedlibrary" command,
709 is now available on all platforms.
711 * Directory names supplied to the "set sysroot" commands may be
712 prefixed with "target:" to tell GDB to access shared libraries from
713 the target system, be it local or remote. This replaces the prefix
714 "remote:". The default sysroot has been changed from "" to
715 "target:". "remote:" is automatically converted to "target:" for
716 backward compatibility.
718 * The system root specified by "set sysroot" will be prepended to the
719 filename of the main executable (if reported to GDB as absolute by
720 the operating system) when starting processes remotely, and when
721 attaching to already-running local or remote processes.
723 * GDB now supports automatic location and retrieval of executable
724 files from remote targets. Remote debugging can now be initiated
725 using only a "target remote" or "target extended-remote" command
726 (no "set sysroot" or "file" commands are required). See "New remote
729 * The "dump" command now supports verilog hex format.
731 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
733 * On GNU/Linux, GDB and gdbserver are now able to access executable
734 and shared library files without a "set sysroot" command when
735 attaching to processes running in different mount namespaces from
736 the debugger. This makes it possible to attach to processes in
737 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
738 See "New remote packets" below.
740 * The "tui reg" command now provides completion for all of the
741 available register groups, including target specific groups.
743 * The HISTSIZE environment variable is no longer read when determining
744 the size of GDB's command history. GDB now instead reads the dedicated
745 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
746 disables truncation of command history. Non-numeric values of GDBHISTSIZE
751 ** Memory ports can now be unbuffered.
755 ** gdb.Objfile objects have a new attribute "username",
756 which is the name of the objfile as specified by the user,
757 without, for example, resolving symlinks.
758 ** You can now write frame unwinders in Python.
759 ** gdb.Type objects have a new method "optimized_out",
760 returning optimized out gdb.Value instance of this type.
761 ** gdb.Value objects have new methods "reference_value" and
762 "const_value" which return a reference to the value and a
763 "const" version of the value respectively.
767 maint print symbol-cache
768 Print the contents of the symbol cache.
770 maint print symbol-cache-statistics
771 Print statistics of symbol cache usage.
773 maint flush-symbol-cache
774 Flush the contents of the symbol cache.
778 Start branch trace recording using Branch Trace Store (BTS) format.
781 Evaluate expression by using the compiler and print result.
785 Explicit commands for enabling and disabling tui mode.
788 set mpx bound on i386 and amd64
789 Support for bound table investigation on Intel MPX enabled applications.
793 Start branch trace recording using Intel Processor Trace format.
796 Print information about branch tracing internals.
798 maint btrace packet-history
799 Print the raw branch tracing data.
801 maint btrace clear-packet-history
802 Discard the stored raw branch tracing data.
805 Discard all branch tracing data. It will be fetched and processed
806 anew by the next "record" command.
811 Renamed from "set debug dwarf2-die".
813 Renamed from "show debug dwarf2-die".
816 Renamed from "set debug dwarf2-read".
817 show debug dwarf-read
818 Renamed from "show debug dwarf2-read".
820 maint set dwarf always-disassemble
821 Renamed from "maint set dwarf2 always-disassemble".
822 maint show dwarf always-disassemble
823 Renamed from "maint show dwarf2 always-disassemble".
825 maint set dwarf max-cache-age
826 Renamed from "maint set dwarf2 max-cache-age".
827 maint show dwarf max-cache-age
828 Renamed from "maint show dwarf2 max-cache-age".
831 show debug dwarf-line
832 Control display of debugging info regarding DWARF line processing.
836 Set the maximum number of candidates to be considered during
837 completion. The default value is 200. This limit allows GDB
838 to avoid generating large completion lists, the computation of
839 which can cause the debugger to become temporarily unresponsive.
841 set history remove-duplicates
842 show history remove-duplicates
843 Control the removal of duplicate history entries.
845 maint set symbol-cache-size
846 maint show symbol-cache-size
847 Control the size of the symbol cache.
849 set|show record btrace bts buffer-size
850 Set and show the size of the ring buffer used for branch tracing in
852 The obtained size may differ from the requested size. Use "info
853 record" to see the obtained buffer size.
855 set debug linux-namespaces
856 show debug linux-namespaces
857 Control display of debugging info regarding Linux namespaces.
859 set|show record btrace pt buffer-size
860 Set and show the size of the ring buffer used for branch tracing in
861 Intel Processor Trace format.
862 The obtained size may differ from the requested size. Use "info
863 record" to see the obtained buffer size.
865 maint set|show btrace pt skip-pad
866 Set and show whether PAD packets are skipped when computing the
869 * The command 'thread apply all' can now support new option '-ascending'
870 to call its specified command for all threads in ascending order.
872 * Python/Guile scripting
874 ** GDB now supports auto-loading of Python/Guile scripts contained in the
875 special section named `.debug_gdb_scripts'.
879 qXfer:btrace-conf:read
880 Return the branch trace configuration for the current thread.
882 Qbtrace-conf:bts:size
883 Set the requested ring buffer size for branch tracing in BTS format.
886 Enable Intel Procesor Trace-based branch tracing for the current
887 process. The remote stub reports support for this packet to GDB's
891 Set the requested ring buffer size for branch tracing in Intel Processor
895 Indicates a memory breakpoint instruction was executed, irrespective
896 of whether it was GDB that planted the breakpoint or the breakpoint
897 is hardcoded in the program. This is required for correct non-stop
901 Indicates the target stopped for a hardware breakpoint. This is
902 required for correct non-stop mode operation.
905 Return information about files on the remote system.
908 Return the full absolute name of the file that was executed to
909 create a process running on the remote system.
912 Select the filesystem on which vFile: operations with filename
913 arguments will operate. This is required for GDB to be able to
914 access files on remote targets where the remote stub does not
915 share a common filesystem with the inferior(s).
918 Indicates that a fork system call was executed.
921 Indicates that a vfork system call was executed.
923 vforkdone stop reason
924 Indicates that a vfork child of the specified process has executed
925 an exec or exit, allowing the vfork parent to resume execution.
927 fork-events and vfork-events features in qSupported
928 The qSupported packet allows GDB to request support for fork and
929 vfork events using new 'gdbfeatures' fork-events and vfork-events,
930 and the qSupported response can contain the corresponding
931 'stubfeatures'. Set and show commands can be used to display
932 whether these features are enabled.
934 * Extended-remote fork events
936 ** GDB now has support for fork events on extended-remote Linux
937 targets. For targets with Linux kernels 2.5.60 and later, this
938 enables follow-fork-mode and detach-on-fork for both fork and
939 vfork, as well as fork and vfork catchpoints.
941 * The info record command now shows the recording format and the
942 branch tracing configuration for the current thread when using
943 the btrace record target.
944 For the BTS format, it shows the ring buffer size.
946 * GDB now has support for DTrace USDT (Userland Static Defined
947 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
949 * GDB now supports access to vector registers on S/390 GNU/Linux
952 * Removed command line options
954 -xdb HP-UX XDB compatibility mode.
956 * Removed targets and native configurations
958 HP/PA running HP-UX hppa*-*-hpux*
959 Itanium running HP-UX ia64-*-hpux*
961 * New configure options
964 This configure option allows the user to build GDB with support for
965 Intel Processor Trace (default: auto). This requires libipt.
967 --with-libipt-prefix=PATH
968 Specify the path to the version of libipt that GDB should use.
969 $PATH/include should contain the intel-pt.h header and
970 $PATH/lib should contain the libipt.so library.
972 *** Changes in GDB 7.9.1
976 ** Xmethods can now specify a result type.
978 *** Changes in GDB 7.9
980 * GDB now supports hardware watchpoints on x86 GNU Hurd.
984 ** You can now access frame registers from Python scripts.
985 ** New attribute 'producer' for gdb.Symtab objects.
986 ** gdb.Objfile objects have a new attribute "progspace",
987 which is the gdb.Progspace object of the containing program space.
988 ** gdb.Objfile objects have a new attribute "owner".
989 ** gdb.Objfile objects have a new attribute "build_id",
990 which is the build ID generated when the file was built.
991 ** gdb.Objfile objects have a new method "add_separate_debug_file".
992 ** A new event "gdb.clear_objfiles" has been added, triggered when
993 selecting a new file to debug.
994 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
995 ** New function gdb.lookup_objfile.
997 New events which are triggered when GDB modifies the state of the
1000 ** gdb.events.inferior_call_pre: Function call is about to be made.
1001 ** gdb.events.inferior_call_post: Function call has just been made.
1002 ** gdb.events.memory_changed: A memory location has been altered.
1003 ** gdb.events.register_changed: A register has been altered.
1005 * New Python-based convenience functions:
1007 ** $_caller_is(name [, number_of_frames])
1008 ** $_caller_matches(regexp [, number_of_frames])
1009 ** $_any_caller_is(name [, number_of_frames])
1010 ** $_any_caller_matches(regexp [, number_of_frames])
1012 * GDB now supports the compilation and injection of source code into
1013 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1014 to compile the source code to object code, and if successful, inject
1015 and execute that code within the current context of the inferior.
1016 Currently the C language is supported. The commands used to
1017 interface with this new feature are:
1019 compile code [-raw|-r] [--] [source code]
1020 compile file [-raw|-r] filename
1024 demangle [-l language] [--] name
1025 Demangle "name" in the specified language, or the current language
1026 if elided. This command is renamed from the "maint demangle" command.
1027 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1028 as "maint demangler-warning".
1030 queue-signal signal-name-or-number
1031 Queue a signal to be delivered to the thread when it is resumed.
1033 add-auto-load-scripts-directory directory
1034 Add entries to the list of directories from which to load auto-loaded
1037 maint print user-registers
1038 List all currently available "user" registers.
1040 compile code [-r|-raw] [--] [source code]
1041 Compile, inject, and execute in the inferior the executable object
1042 code produced by compiling the provided source code.
1044 compile file [-r|-raw] filename
1045 Compile and inject into the inferior the executable object code
1046 produced by compiling the source code stored in the filename
1049 * On resume, GDB now always passes the signal the program had stopped
1050 for to the thread the signal was sent to, even if the user changed
1051 threads before resuming. Previously GDB would often (but not
1052 always) deliver the signal to the thread that happens to be current
1055 * Conversely, the "signal" command now consistently delivers the
1056 requested signal to the current thread. GDB now asks for
1057 confirmation if the program had stopped for a signal and the user
1058 switched threads meanwhile.
1060 * "breakpoint always-inserted" modes "off" and "auto" merged.
1062 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1063 won't remove breakpoints from the target until all threads stop,
1064 even in non-stop mode. The "auto" mode has been removed, and "off"
1065 is now the default mode.
1069 set debug symbol-lookup
1070 show debug symbol-lookup
1071 Control display of debugging info regarding symbol lookup.
1075 ** The -list-thread-groups command outputs an exit-code field for
1076 inferiors that have exited.
1080 MIPS SDE mips*-sde*-elf*
1084 Support for these obsolete configurations has been removed.
1086 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1087 SGI Irix-5.x mips-*-irix5*
1088 SGI Irix-6.x mips-*-irix6*
1089 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1090 VAX running Ultrix vax-*-ultrix*
1092 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1093 and "assf"), have been removed. Use the "sharedlibrary" command, or
1094 its alias "share", instead.
1096 *** Changes in GDB 7.8
1098 * New command line options
1101 This is an alias for the --data-directory option.
1103 * GDB supports printing and modifying of variable length automatic arrays
1104 as specified in ISO C99.
1106 * The ARM simulator now supports instruction level tracing
1107 with or without disassembly.
1111 GDB now has support for scripting using Guile. Whether this is
1112 available is determined at configure time.
1113 Guile version 2.0 or greater is required.
1114 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1116 * New commands (for set/show, see "New options" below)
1120 Invoke CODE by passing it to the Guile interpreter.
1124 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1126 info auto-load guile-scripts [regexp]
1127 Print the list of automatically loaded Guile scripts.
1129 * The source command is now capable of sourcing Guile scripts.
1130 This feature is dependent on the debugger being built with Guile support.
1134 set print symbol-loading (off|brief|full)
1135 show print symbol-loading
1136 Control whether to print informational messages when loading symbol
1137 information for a file. The default is "full", but when debugging
1138 programs with large numbers of shared libraries the amount of output
1139 becomes less useful.
1141 set guile print-stack (none|message|full)
1142 show guile print-stack
1143 Show a stack trace when an error is encountered in a Guile script.
1145 set auto-load guile-scripts (on|off)
1146 show auto-load guile-scripts
1147 Control auto-loading of Guile script files.
1149 maint ada set ignore-descriptive-types (on|off)
1150 maint ada show ignore-descriptive-types
1151 Control whether the debugger should ignore descriptive types in Ada
1152 programs. The default is not to ignore the descriptive types. See
1153 the user manual for more details on descriptive types and the intended
1154 usage of this option.
1156 set auto-connect-native-target
1158 Control whether GDB is allowed to automatically connect to the
1159 native target for the run, attach, etc. commands when not connected
1160 to any target yet. See also "target native" below.
1162 set record btrace replay-memory-access (read-only|read-write)
1163 show record btrace replay-memory-access
1164 Control what memory accesses are allowed during replay.
1166 maint set target-async (on|off)
1167 maint show target-async
1168 This controls whether GDB targets operate in synchronous or
1169 asynchronous mode. Normally the default is asynchronous, if it is
1170 available; but this can be changed to more easily debug problems
1171 occurring only in synchronous mode.
1173 set mi-async (on|off)
1175 Control whether MI asynchronous mode is preferred. This supersedes
1176 "set target-async" of previous GDB versions.
1178 * "set target-async" is deprecated as a CLI option and is now an alias
1179 for "set mi-async" (only puts MI into async mode).
1181 * Background execution commands (e.g., "c&", "s&", etc.) are now
1182 possible ``out of the box'' if the target supports them. Previously
1183 the user would need to explicitly enable the possibility with the
1184 "set target-async on" command.
1186 * New features in the GDB remote stub, GDBserver
1188 ** New option --debug-format=option1[,option2,...] allows one to add
1189 additional text to each output. At present only timestamps
1190 are supported: --debug-format=timestamps.
1191 Timestamps can also be turned on with the
1192 "monitor set debug-format timestamps" command from GDB.
1194 * The 'record instruction-history' command now starts counting instructions
1195 at one. This also affects the instruction ranges reported by the
1196 'record function-call-history' command when given the /i modifier.
1198 * The command 'record function-call-history' supports a new modifier '/c' to
1199 indent the function names based on their call stack depth.
1200 The fields for the '/i' and '/l' modifier have been reordered.
1201 The source line range is now prefixed with 'at'.
1202 The instruction range is now prefixed with 'inst'.
1203 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1204 "record instruction-history" and "list" commands.
1206 * The ranges given as arguments to the 'record function-call-history' and
1207 'record instruction-history' commands are now inclusive.
1209 * The btrace record target now supports the 'record goto' command.
1210 For locations inside the execution trace, the back trace is computed
1211 based on the information stored in the execution trace.
1213 * The btrace record target supports limited reverse execution and replay.
1214 The target does not record data and therefore does not allow reading
1215 memory or registers.
1217 * The "catch syscall" command now works on s390*-linux* targets.
1219 * The "compare-sections" command is no longer specific to target
1220 remote. It now works with all targets.
1222 * All native targets are now consistently called "native".
1223 Consequently, the "target child", "target GNU", "target djgpp",
1224 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1225 commands have been replaced with "target native". The QNX/NTO port
1226 leaves the "procfs" target in place and adds a "native" target for
1227 consistency with other ports. The impact on users should be minimal
1228 as these commands previously either throwed an error, or were
1229 no-ops. The target's name is visible in the output of the following
1230 commands: "help target", "info target", "info files", "maint print
1233 * The "target native" command now connects to the native target. This
1234 can be used to launch native programs even when "set
1235 auto-connect-native-target" is set to off.
1237 * GDB now supports access to Intel MPX registers on GNU/Linux.
1239 * Support for Intel AVX-512 registers on GNU/Linux.
1240 Support displaying and modifying Intel AVX-512 registers
1241 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1243 * New remote packets
1245 qXfer:btrace:read's annex
1246 The qXfer:btrace:read packet supports a new annex 'delta' to read
1247 branch trace incrementally.
1251 ** Valid Python operations on gdb.Value objects representing
1252 structs/classes invoke the corresponding overloaded operators if
1254 ** New `Xmethods' feature in the Python API. Xmethods are
1255 additional methods or replacements for existing methods of a C++
1256 class. This feature is useful for those cases where a method
1257 defined in C++ source code could be inlined or optimized out by
1258 the compiler, making it unavailable to GDB.
1261 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1263 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1264 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1265 its alias "share", instead.
1267 * The commands "set remotebaud" and "show remotebaud" are no longer
1268 supported. Use "set serial baud" and "show serial baud" (respectively)
1273 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1274 target-async". The latter is left as a deprecated alias of the
1275 former for backward compatibility. If the target supports it,
1276 CLI background execution commands are now always possible by
1277 default, independently of whether the frontend stated a
1278 preference for asynchronous execution with "-gdb-set mi-async".
1279 Previously "-gdb-set target-async off" affected both MI execution
1280 commands and CLI execution commands.
1282 *** Changes in GDB 7.7
1284 * Improved support for process record-replay and reverse debugging on
1285 arm*-linux* targets. Support for thumb32 and syscall instruction
1286 recording has been added.
1288 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1290 * GDB now supports Fission DWP file format version 2.
1291 http://gcc.gnu.org/wiki/DebugFission
1293 * New convenience function "$_isvoid", to check whether an expression
1294 is void. A void expression is an expression where the type of the
1295 result is "void". For example, some convenience variables may be
1296 "void" when evaluated (e.g., "$_exitcode" before the execution of
1297 the program being debugged; or an undefined convenience variable).
1298 Another example, when calling a function whose return type is
1301 * The "maintenance print objfiles" command now takes an optional regexp.
1303 * The "catch syscall" command now works on arm*-linux* targets.
1305 * GDB now consistently shows "<not saved>" when printing values of
1306 registers the debug info indicates have not been saved in the frame
1307 and there's nowhere to retrieve them from
1308 (callee-saved/call-clobbered registers):
1313 (gdb) info registers rax
1316 Before, the former would print "<optimized out>", and the latter
1317 "*value not available*".
1319 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1324 ** Frame filters and frame decorators have been added.
1325 ** Temporary breakpoints are now supported.
1326 ** Line tables representation has been added.
1327 ** New attribute 'parent_type' for gdb.Field objects.
1328 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1329 ** New attribute 'name' for gdb.Type objects.
1333 Nios II ELF nios2*-*-elf
1334 Nios II GNU/Linux nios2*-*-linux
1335 Texas Instruments MSP430 msp430*-*-elf
1337 * Removed native configurations
1339 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1340 been removed. ELF variants of these configurations are kept supported.
1342 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1343 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1344 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1345 i[34567]86-*-openbsd3.[0-3]
1346 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1347 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1348 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1352 Like "catch throw", but catches a re-thrown exception.
1353 maint check-psymtabs
1354 Renamed from old "maint check-symtabs".
1356 Perform consistency checks on symtabs.
1357 maint expand-symtabs
1358 Expand symtabs matching an optional regexp.
1361 Display the details of GDB configure-time options.
1363 maint set|show per-command
1364 maint set|show per-command space
1365 maint set|show per-command time
1366 maint set|show per-command symtab
1367 Enable display of per-command gdb resource usage.
1369 remove-symbol-file FILENAME
1370 remove-symbol-file -a ADDRESS
1371 Remove a symbol file added via add-symbol-file. The file to remove
1372 can be identified by its filename or by an address that lies within
1373 the boundaries of this symbol file in memory.
1376 info exceptions REGEXP
1377 Display the list of Ada exceptions defined in the program being
1378 debugged. If provided, only the exceptions whose names match REGEXP
1383 set debug symfile off|on
1385 Control display of debugging info regarding reading symbol files and
1386 symbol tables within those files
1388 set print raw frame-arguments
1389 show print raw frame-arguments
1390 Set/show whether to print frame arguments in raw mode,
1391 disregarding any defined pretty-printers.
1393 set remote trace-status-packet
1394 show remote trace-status-packet
1395 Set/show the use of remote protocol qTStatus packet.
1399 Control display of debugging messages related to Nios II targets.
1403 Control whether target-assisted range stepping is enabled.
1405 set startup-with-shell
1406 show startup-with-shell
1407 Specifies whether Unix child processes are started via a shell or
1412 Use the target memory cache for accesses to the code segment. This
1413 improves performance of remote debugging (particularly disassembly).
1415 * You can now use a literal value 'unlimited' for options that
1416 interpret 0 or -1 as meaning "unlimited". E.g., "set
1417 trace-buffer-size unlimited" is now an alias for "set
1418 trace-buffer-size -1" and "set height unlimited" is now an alias for
1421 * The "set debug symtab-create" debugging option of GDB has been changed to
1422 accept a verbosity level. 0 means "off", 1 provides basic debugging
1423 output, and values of 2 or greater provides more verbose output.
1425 * New command-line options
1427 Display the details of GDB configure-time options.
1429 * The command 'tsave' can now support new option '-ctf' to save trace
1430 buffer in Common Trace Format.
1432 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1435 * GDB now implements the the C++ 'typeid' operator.
1437 * The new convenience variable $_exception holds the exception being
1438 thrown or caught at an exception-related catchpoint.
1440 * The exception-related catchpoints, like "catch throw", now accept a
1441 regular expression which can be used to filter exceptions by type.
1443 * The new convenience variable $_exitsignal is automatically set to
1444 the terminating signal number when the program being debugged dies
1445 due to an uncaught signal.
1449 ** All MI commands now accept an optional "--language" option.
1450 Support for this feature can be verified by using the "-list-features"
1451 command, which should contain "language-option".
1453 ** The new command -info-gdb-mi-command allows the user to determine
1454 whether a GDB/MI command is supported or not.
1456 ** The "^error" result record returned when trying to execute an undefined
1457 GDB/MI command now provides a variable named "code" whose content is the
1458 "undefined-command" error code. Support for this feature can be verified
1459 by using the "-list-features" command, which should contain
1460 "undefined-command-error-code".
1462 ** The -trace-save MI command can optionally save trace buffer in Common
1465 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1467 ** The command -data-list-register-values now accepts an optional
1468 "--skip-unavailable" option. When used, only the available registers
1471 ** The new command -trace-frame-collected dumps collected variables,
1472 computed expressions, tvars, memory and registers in a traceframe.
1474 ** The commands -stack-list-locals, -stack-list-arguments and
1475 -stack-list-variables now accept an option "--skip-unavailable".
1476 When used, only the available locals or arguments are displayed.
1478 ** The -exec-run command now accepts an optional "--start" option.
1479 When used, the command follows the same semantics as the "start"
1480 command, stopping the program's execution at the start of its
1481 main subprogram. Support for this feature can be verified using
1482 the "-list-features" command, which should contain
1483 "exec-run-start-option".
1485 ** The new commands -catch-assert and -catch-exceptions insert
1486 catchpoints stopping the program when Ada exceptions are raised.
1488 ** The new command -info-ada-exceptions provides the equivalent of
1489 the new "info exceptions" command.
1491 * New system-wide configuration scripts
1492 A GDB installation now provides scripts suitable for use as system-wide
1493 configuration scripts for the following systems:
1497 * GDB now supports target-assigned range stepping with remote targets.
1498 This improves the performance of stepping source lines by reducing
1499 the number of control packets from/to GDB. See "New remote packets"
1502 * GDB now understands the element 'tvar' in the XML traceframe info.
1503 It has the id of the collected trace state variables.
1505 * On S/390 targets that provide the transactional-execution feature,
1506 the program interruption transaction diagnostic block (TDB) is now
1507 represented as a number of additional "registers" in GDB.
1509 * New remote packets
1513 The vCont packet supports a new 'r' action, that tells the remote
1514 stub to step through an address range itself, without GDB
1515 involvemement at each single-step.
1517 qXfer:libraries-svr4:read's annex
1518 The previously unused annex of the qXfer:libraries-svr4:read packet
1519 is now used to support passing an argument list. The remote stub
1520 reports support for this argument list to GDB's qSupported query.
1521 The defined arguments are "start" and "prev", used to reduce work
1522 necessary for library list updating, resulting in significant
1525 * New features in the GDB remote stub, GDBserver
1527 ** GDBserver now supports target-assisted range stepping. Currently
1528 enabled on x86/x86_64 GNU/Linux targets.
1530 ** GDBserver now adds element 'tvar' in the XML in the reply to
1531 'qXfer:traceframe-info:read'. It has the id of the collected
1532 trace state variables.
1534 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1537 * New 'z' formatter for printing and examining memory, this displays the
1538 value as hexadecimal zero padded on the left to the size of the type.
1540 * GDB can now use Windows x64 unwinding data.
1542 * The "set remotebaud" command has been replaced by "set serial baud".
1543 Similarly, "show remotebaud" has been replaced by "show serial baud".
1544 The "set remotebaud" and "show remotebaud" commands are still available
1545 to provide backward compatibility with older versions of GDB.
1547 *** Changes in GDB 7.6
1549 * Target record has been renamed to record-full.
1550 Record/replay is now enabled with the "record full" command.
1551 This also affects settings that are associated with full record/replay
1552 that have been moved from "set/show record" to "set/show record full":
1554 set|show record full insn-number-max
1555 set|show record full stop-at-limit
1556 set|show record full memory-query
1558 * A new record target "record-btrace" has been added. The new target
1559 uses hardware support to record the control-flow of a process. It
1560 does not support replaying the execution, but it implements the
1561 below new commands for investigating the recorded execution log.
1562 This new recording method can be enabled using:
1566 The "record-btrace" target is only available on Intel Atom processors
1567 and requires a Linux kernel 2.6.32 or later.
1569 * Two new commands have been added for record/replay to give information
1570 about the recorded execution without having to replay the execution.
1571 The commands are only supported by "record btrace".
1573 record instruction-history prints the execution history at
1574 instruction granularity
1576 record function-call-history prints the execution history at
1577 function granularity
1579 * New native configurations
1581 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1582 FreeBSD/powerpc powerpc*-*-freebsd
1583 x86_64/Cygwin x86_64-*-cygwin*
1584 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1588 ARM AArch64 aarch64*-*-elf
1589 ARM AArch64 GNU/Linux aarch64*-*-linux
1590 Lynx 178 PowerPC powerpc-*-lynx*178
1591 x86_64/Cygwin x86_64-*-cygwin*
1592 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1594 * If the configured location of system.gdbinit file (as given by the
1595 --with-system-gdbinit option at configure time) is in the
1596 data-directory (as specified by --with-gdb-datadir at configure
1597 time) or in one of its subdirectories, then GDB will look for the
1598 system-wide init file in the directory specified by the
1599 --data-directory command-line option.
1601 * New command line options:
1603 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1604 other initialization files, unlike -nx which disables all of them.
1606 * Removed command line options
1608 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1611 * The 'ptype' and 'whatis' commands now accept an argument to control
1614 * 'info proc' now works on some core files.
1618 ** Vectors can be created with gdb.Type.vector.
1620 ** Python's atexit.register now works in GDB.
1622 ** Types can be pretty-printed via a Python API.
1624 ** Python 3 is now supported (in addition to Python 2.4 or later)
1626 ** New class gdb.Architecture exposes GDB's internal representation
1627 of architecture in the Python API.
1629 ** New method Frame.architecture returns the gdb.Architecture object
1630 corresponding to the frame's architecture.
1632 * New Python-based convenience functions:
1634 ** $_memeq(buf1, buf2, length)
1635 ** $_streq(str1, str2)
1637 ** $_regex(str, regex)
1639 * The 'cd' command now defaults to using '~' (the home directory) if not
1642 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1643 default for GCC since November 2000.
1645 * The command 'forward-search' can now be abbreviated as 'fo'.
1647 * The command 'info tracepoints' can now display 'installed on target'
1648 or 'not installed on target' for each non-pending location of tracepoint.
1650 * New configure options
1652 --enable-libmcheck/--disable-libmcheck
1653 By default, development versions are built with -lmcheck on hosts
1654 that support it, in order to help track memory corruption issues.
1655 Release versions, on the other hand, are built without -lmcheck
1656 by default. The --enable-libmcheck/--disable-libmcheck configure
1657 options allow the user to override that default.
1658 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1659 This configure option allows the user to build GDB with
1660 libbabeltrace using which GDB can read Common Trace Format data.
1662 * New commands (for set/show, see "New options" below)
1665 Catch signals. This is similar to "handle", but allows commands and
1666 conditions to be attached.
1669 List the BFDs known to GDB.
1671 python-interactive [command]
1673 Start a Python interactive prompt, or evaluate the optional command
1674 and print the result of expressions.
1677 "py" is a new alias for "python".
1679 enable type-printer [name]...
1680 disable type-printer [name]...
1681 Enable or disable type printers.
1685 ** For the Renesas Super-H architecture, the "regs" command has been removed
1686 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1691 set print type methods (on|off)
1692 show print type methods
1693 Control whether method declarations are displayed by "ptype".
1694 The default is to show them.
1696 set print type typedefs (on|off)
1697 show print type typedefs
1698 Control whether typedef definitions are displayed by "ptype".
1699 The default is to show them.
1701 set filename-display basename|relative|absolute
1702 show filename-display
1703 Control the way in which filenames is displayed.
1704 The default is "relative", which preserves previous behavior.
1706 set trace-buffer-size
1707 show trace-buffer-size
1708 Request target to change the size of trace buffer.
1710 set remote trace-buffer-size-packet auto|on|off
1711 show remote trace-buffer-size-packet
1712 Control the use of the remote protocol `QTBuffer:size' packet.
1716 Control display of debugging messages related to ARM AArch64.
1719 set debug coff-pe-read
1720 show debug coff-pe-read
1721 Control display of debugging messages related to reading of COFF/PE
1726 Control display of debugging messages related to Mach-O symbols
1729 set debug notification
1730 show debug notification
1731 Control display of debugging info for async remote notification.
1735 ** Command parameter changes are now notified using new async record
1736 "=cmd-param-changed".
1737 ** Trace frame changes caused by command "tfind" are now notified using
1738 new async record "=traceframe-changed".
1739 ** The creation, deletion and modification of trace state variables
1740 are now notified using new async records "=tsv-created",
1741 "=tsv-deleted" and "=tsv-modified".
1742 ** The start and stop of process record are now notified using new
1743 async record "=record-started" and "=record-stopped".
1744 ** Memory changes are now notified using new async record
1746 ** The data-disassemble command response will include a "fullname" field
1747 containing the absolute file name when source has been requested.
1748 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1749 command, to allow pattern filling of memory areas.
1750 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1751 library load/unload events.
1752 ** The response to breakpoint commands and breakpoint async records
1753 includes an "installed" field containing a boolean state about each
1754 non-pending tracepoint location is whether installed on target or not.
1755 ** Output of the "-trace-status" command includes a "trace-file" field
1756 containing the name of the trace file being examined. This field is
1757 optional, and only present when examining a trace file.
1758 ** The "fullname" field is now always present along with the "file" field,
1759 even if the file cannot be found by GDB.
1761 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1762 You must have the LZMA library available when configuring GDB for this
1763 feature to be enabled. For more information, see:
1764 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1766 * New remote packets
1769 Set the size of trace buffer. The remote stub reports support for this
1770 packet to gdb's qSupported query.
1773 Enable Branch Trace Store (BTS)-based branch tracing for the current
1774 thread. The remote stub reports support for this packet to gdb's
1778 Disable branch tracing for the current thread. The remote stub reports
1779 support for this packet to gdb's qSupported query.
1782 Read the traced branches for the current thread. The remote stub
1783 reports support for this packet to gdb's qSupported query.
1785 *** Changes in GDB 7.5
1787 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1788 for more x32 ABI info.
1790 * GDB now supports access to MIPS DSP registers on Linux targets.
1792 * GDB now supports debugging microMIPS binaries.
1794 * The "info os" command on GNU/Linux can now display information on
1795 several new classes of objects managed by the operating system:
1796 "info os procgroups" lists process groups
1797 "info os files" lists file descriptors
1798 "info os sockets" lists internet-domain sockets
1799 "info os shm" lists shared-memory regions
1800 "info os semaphores" lists semaphores
1801 "info os msg" lists message queues
1802 "info os modules" lists loaded kernel modules
1804 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1805 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1806 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1807 options and inspect the probe arguments using the new $_probe_arg family
1808 of convenience variables. You can obtain more information about SystemTap
1809 in <http://sourceware.org/systemtap/>.
1811 * GDB now supports reversible debugging on ARM, it allows you to
1812 debug basic ARM and THUMB instructions, and provides
1813 record/replay support.
1815 * The option "symbol-reloading" has been deleted as it is no longer used.
1819 ** GDB commands implemented in Python can now be put in command class
1822 ** The "maint set python print-stack on|off" is now deleted.
1824 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1825 apply "flag enum"-style pretty-printing to any enum.
1827 ** gdb.lookup_symbol can now work when there is no current frame.
1829 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1830 the source at which the symbol was defined.
1832 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1833 method 'value'. The former indicates whether the symbol needs a
1834 frame in order to compute its value, and the latter computes the
1837 ** A new method 'referenced_value' on gdb.Value objects which can
1838 dereference pointer as well as C++ reference values.
1840 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1841 which return the global and static blocks (as gdb.Block objects),
1842 of the underlying symbol table, respectively.
1844 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1845 object associated with a PC value.
1847 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1848 of the address range occupied by code for the current source line.
1850 * Go language support.
1851 GDB now supports debugging programs written in the Go programming
1854 * GDBserver now supports stdio connections.
1855 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1857 * The binary "gdbtui" can no longer be built or installed.
1858 Use "gdb -tui" instead.
1860 * GDB will now print "flag" enums specially. A flag enum is one where
1861 all the enumerator values have no bits in common when pairwise
1862 "and"ed. When printing a value whose type is a flag enum, GDB will
1863 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1864 (gdb) print (enum E) 3
1867 * The filename part of a linespec will now match trailing components
1868 of a source file name. For example, "break gcc/expr.c:1000" will
1869 now set a breakpoint in build/gcc/expr.c, but not
1870 build/libcpp/expr.c.
1872 * The "info proc" and "generate-core-file" commands will now also
1873 work on remote targets connected to GDBserver on Linux.
1875 * The command "info catch" has been removed. It has been disabled
1876 since December 2007.
1878 * The "catch exception" and "catch assert" commands now accept
1879 a condition at the end of the command, much like the "break"
1880 command does. For instance:
1882 (gdb) catch exception Constraint_Error if Barrier = True
1884 Previously, it was possible to add a condition to such catchpoints,
1885 but it had to be done as a second step, after the catchpoint had been
1886 created, using the "condition" command.
1888 * The "info static-tracepoint-marker" command will now also work on
1889 native Linux targets with in-process agent.
1891 * GDB can now set breakpoints on inlined functions.
1893 * The .gdb_index section has been updated to include symbols for
1894 inlined functions. GDB will ignore older .gdb_index sections by
1895 default, which could cause symbol files to be loaded more slowly
1896 until their .gdb_index sections can be recreated. The new command
1897 "set use-deprecated-index-sections on" will cause GDB to use any older
1898 .gdb_index sections it finds. This will restore performance, but the
1899 ability to set breakpoints on inlined functions will be lost in symbol
1900 files with older .gdb_index sections.
1902 The .gdb_index section has also been updated to record more information
1903 about each symbol. This speeds up the "info variables", "info functions"
1904 and "info types" commands when used with programs having the .gdb_index
1905 section, as well as speeding up debugging with shared libraries using
1906 the .gdb_index section.
1908 * Ada support for GDB/MI Variable Objects has been added.
1910 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1915 ** New command -info-os is the MI equivalent of "info os".
1917 ** Output logs ("set logging" and related) now include MI output.
1921 ** "set use-deprecated-index-sections on|off"
1922 "show use-deprecated-index-sections on|off"
1923 Controls the use of deprecated .gdb_index sections.
1925 ** "catch load" and "catch unload" can be used to stop when a shared
1926 library is loaded or unloaded, respectively.
1928 ** "enable count" can be used to auto-disable a breakpoint after
1931 ** "info vtbl" can be used to show the virtual method tables for
1932 C++ and Java objects.
1934 ** "explore" and its sub commands "explore value" and "explore type"
1935 can be used to recursively explore values and types of
1936 expressions. These commands are available only if GDB is
1937 configured with '--with-python'.
1939 ** "info auto-load" shows status of all kinds of auto-loaded files,
1940 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1941 sequences of commands files, "info auto-load python-scripts"
1942 shows status of auto-loading Python script files,
1943 "info auto-load local-gdbinit" shows status of loading init file
1944 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1945 status of inferior specific thread debugging shared library loading.
1947 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1948 and "show auto-load-scripts" commands have been deprecated, use their
1949 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1950 and "show auto-load python-scripts" counterparts instead.
1952 ** "dprintf location,format,args..." creates a dynamic printf, which
1953 is basically a breakpoint that does a printf and immediately
1954 resumes your program's execution, so it is like a printf that you
1955 can insert dynamically at runtime instead of at compiletime.
1957 ** "set print symbol"
1959 Controls whether GDB attempts to display the symbol, if any,
1960 corresponding to addresses it prints. This defaults to "on", but
1961 you can set it to "off" to restore GDB's previous behavior.
1963 * Deprecated commands
1965 ** For the Renesas Super-H architecture, the "regs" command has been
1966 deprecated, and "info all-registers" should be used instead.
1970 Renesas RL78 rl78-*-elf
1971 HP OpenVMS ia64 ia64-hp-openvms*
1973 * GDBserver supports evaluation of breakpoint conditions. When
1974 support is advertised by GDBserver, GDB may be told to send the
1975 breakpoint conditions in bytecode form to GDBserver. GDBserver
1976 will only report the breakpoint trigger to GDB when its condition
1981 set mips compression
1982 show mips compression
1983 Select the compressed ISA encoding used in functions that have no symbol
1984 information available. The encoding can be set to either of:
1987 and is updated automatically from ELF file flags if available.
1989 set breakpoint condition-evaluation
1990 show breakpoint condition-evaluation
1991 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1992 GDBserver ("target"). Default option "auto" chooses the most efficient
1994 This option can improve debugger efficiency depending on the speed of the
1998 Disable auto-loading globally.
2001 Show auto-loading setting of all kinds of auto-loaded files.
2003 set auto-load gdb-scripts on|off
2004 show auto-load gdb-scripts
2005 Control auto-loading of GDB canned sequences of commands files.
2007 set auto-load python-scripts on|off
2008 show auto-load python-scripts
2009 Control auto-loading of Python script files.
2011 set auto-load local-gdbinit on|off
2012 show auto-load local-gdbinit
2013 Control loading of init file (.gdbinit) from current directory.
2015 set auto-load libthread-db on|off
2016 show auto-load libthread-db
2017 Control auto-loading of inferior specific thread debugging shared library.
2019 set auto-load scripts-directory <dir1>[:<dir2>...]
2020 show auto-load scripts-directory
2021 Set a list of directories from which to load auto-loaded scripts.
2022 Automatically loaded Python scripts and GDB scripts are located in one
2023 of the directories listed by this option.
2024 The delimiter (':' above) may differ according to the host platform.
2026 set auto-load safe-path <dir1>[:<dir2>...]
2027 show auto-load safe-path
2028 Set a list of directories from which it is safe to auto-load files.
2029 The delimiter (':' above) may differ according to the host platform.
2031 set debug auto-load on|off
2032 show debug auto-load
2033 Control display of debugging info for auto-loading the files above.
2035 set dprintf-style gdb|call|agent
2037 Control the way in which a dynamic printf is performed; "gdb"
2038 requests a GDB printf command, while "call" causes dprintf to call a
2039 function in the inferior. "agent" requests that the target agent
2040 (such as GDBserver) do the printing.
2042 set dprintf-function <expr>
2043 show dprintf-function
2044 set dprintf-channel <expr>
2045 show dprintf-channel
2046 Set the function and optional first argument to the call when using
2047 the "call" style of dynamic printf.
2049 set disconnected-dprintf on|off
2050 show disconnected-dprintf
2051 Control whether agent-style dynamic printfs continue to be in effect
2052 after GDB disconnects.
2054 * New configure options
2056 --with-auto-load-dir
2057 Configure default value for the 'set auto-load scripts-directory'
2058 setting above. It defaults to '$debugdir:$datadir/auto-load',
2059 $debugdir representing global debugging info directories (available
2060 via 'show debug-file-directory') and $datadir representing GDB's data
2061 directory (available via 'show data-directory').
2063 --with-auto-load-safe-path
2064 Configure default value for the 'set auto-load safe-path' setting
2065 above. It defaults to the --with-auto-load-dir setting.
2067 --without-auto-load-safe-path
2068 Set 'set auto-load safe-path' to '/', effectively disabling this
2071 * New remote packets
2073 z0/z1 conditional breakpoints extension
2075 The z0/z1 breakpoint insertion packets have been extended to carry
2076 a list of conditional expressions over to the remote stub depending on the
2077 condition evaluation mode. The use of this extension can be controlled
2078 via the "set remote conditional-breakpoints-packet" command.
2082 Specify the signals which the remote stub may pass to the debugged
2083 program without GDB involvement.
2085 * New command line options
2087 --init-command=FILE, -ix Like --command, -x but execute it
2088 before loading inferior.
2089 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2090 execute it before loading inferior.
2092 *** Changes in GDB 7.4
2094 * GDB now handles ambiguous linespecs more consistently; the existing
2095 FILE:LINE support has been expanded to other types of linespecs. A
2096 breakpoint will now be set on all matching locations in all
2097 inferiors, and locations will be added or removed according to
2100 * GDB now allows you to skip uninteresting functions and files when
2101 stepping with the "skip function" and "skip file" commands.
2103 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2104 and "show remote hardware-watchpoint-length-limit". These allows to
2105 set or show the maximum length limit (in bytes) of a remote
2106 target hardware watchpoint.
2108 This allows e.g. to use "unlimited" hardware watchpoints with the
2109 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2110 watchpoints are slower than real hardware watchpoints but are
2111 significantly faster than gdb software watchpoints.
2115 ** The register_pretty_printer function in module gdb.printing now takes
2116 an optional `replace' argument. If True, the new printer replaces any
2119 ** The "maint set python print-stack on|off" command has been
2120 deprecated and will be deleted in GDB 7.5.
2121 A new command: "set python print-stack none|full|message" has
2122 replaced it. Additionally, the default for "print-stack" is
2123 now "message", which just prints the error message without
2126 ** A prompt substitution hook (prompt_hook) is now available to the
2129 ** A new Python module, gdb.prompt has been added to the GDB Python
2130 modules library. This module provides functionality for
2131 escape sequences in prompts (used by set/show
2132 extended-prompt). These escape sequences are replaced by their
2133 corresponding value.
2135 ** Python commands and convenience-functions located in
2136 'data-directory'/python/gdb/command and
2137 'data-directory'/python/gdb/function are now automatically loaded
2140 ** Blocks now provide four new attributes. global_block and
2141 static_block will return the global and static blocks
2142 respectively. is_static and is_global are boolean attributes
2143 that indicate if the block is one of those two types.
2145 ** Symbols now provide the "type" attribute, the type of the symbol.
2147 ** The "gdb.breakpoint" function has been deprecated in favor of
2150 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2151 of a function. This class is based on the "finish" command
2152 available in the CLI.
2154 ** Type objects for struct and union types now allow access to
2155 the fields using standard Python dictionary (mapping) methods.
2156 For example, "some_type['myfield']" now works, as does
2157 "some_type.items()".
2159 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2162 ** A new function, "deep_items" has been added to the gdb.types
2163 module in the GDB Python modules library. This function returns
2164 an iterator over the fields of a struct or union type. Unlike
2165 the standard Python "iteritems" method, it will recursively traverse
2166 any anonymous fields.
2170 ** "*stopped" events can report several new "reason"s, such as
2173 ** Breakpoint changes are now notified using new async records, like
2174 "=breakpoint-modified".
2176 ** New command -ada-task-info.
2178 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2179 $sdir specifies the default system locations of shared libraries.
2180 $pdir specifies the directory where the libpthread used by the application
2183 GDB no longer looks in $sdir and $pdir after it has searched the directories
2184 mentioned in libthread-db-search-path. If you want to search those
2185 directories, they must be specified in libthread-db-search-path.
2186 The default value of libthread-db-search-path on GNU/Linux and Solaris
2187 systems is now "$sdir:$pdir".
2189 $pdir is not supported by gdbserver, it is currently ignored.
2190 $sdir is supported by gdbserver.
2192 * New configure option --with-iconv-bin.
2193 When using the internationalization support like the one in the GNU C
2194 library, GDB will invoke the "iconv" program to get a list of supported
2195 character sets. If this program lives in a non-standard location, one can
2196 use this option to specify where to find it.
2198 * When natively debugging programs on PowerPC BookE processors running
2199 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2200 watchpoints, which specify a mask in addition to an address to watch.
2201 The mask specifies that some bits of an address (the bits which are
2202 reset in the mask) should be ignored when matching the address accessed
2203 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2204 section in the user manual for more details.
2206 * The new option --once causes GDBserver to stop listening for connections once
2207 the first connection is made. The listening port used by GDBserver will
2208 become available after that.
2210 * New commands "info macros" and "alias" have been added.
2212 * New function parameters suffix @entry specifies value of function parameter
2213 at the time the function got called. Entry values are available only since
2219 "!" is now an alias of the "shell" command.
2220 Note that no space is needed between "!" and SHELL COMMAND.
2224 watch EXPRESSION mask MASK_VALUE
2225 The watch command now supports the mask argument which allows creation
2226 of masked watchpoints, if the current architecture supports this feature.
2228 info auto-load-scripts [REGEXP]
2229 This command was formerly named "maintenance print section-scripts".
2230 It is now generally useful and is no longer a maintenance-only command.
2232 info macro [-all] [--] MACRO
2233 The info macro command has new options `-all' and `--'. The first for
2234 printing all definitions of a macro. The second for explicitly specifying
2235 the end of arguments and the beginning of the macro name in case the macro
2236 name starts with a hyphen.
2238 collect[/s] EXPRESSIONS
2239 The tracepoint collect command now takes an optional modifier "/s"
2240 that directs it to dereference pointer-to-character types and
2241 collect the bytes of memory up to a zero byte. The behavior is
2242 similar to what you see when you use the regular print command on a
2243 string. An optional integer following the "/s" sets a bound on the
2244 number of bytes that will be collected.
2247 The trace start command now interprets any supplied arguments as a
2248 note to be recorded with the trace run, with an effect similar to
2249 setting the variable trace-notes.
2252 The trace stop command now interprets any arguments as a note to be
2253 mentioned along with the tstatus report that the trace was stopped
2254 with a command. The effect is similar to setting the variable
2257 * Tracepoints can now be enabled and disabled at any time after a trace
2258 experiment has been started using the standard "enable" and "disable"
2259 commands. It is now possible to start a trace experiment with no enabled
2260 tracepoints; GDB will display a warning, but will allow the experiment to
2261 begin, assuming that tracepoints will be enabled as needed while the trace
2264 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2265 locations with 4-byte instructions, when they were previously
2266 limited to locations with instructions of 5 bytes or longer.
2270 set debug dwarf2-read
2271 show debug dwarf2-read
2272 Turns on or off display of debugging messages related to reading
2273 DWARF debug info. The default is off.
2275 set debug symtab-create
2276 show debug symtab-create
2277 Turns on or off display of debugging messages related to symbol table
2278 creation. The default is off.
2281 show extended-prompt
2282 Set the GDB prompt, and allow escape sequences to be inserted to
2283 display miscellaneous information (see 'help set extended-prompt'
2284 for the list of sequences). This prompt (and any information
2285 accessed through the escape sequences) is updated every time the
2286 prompt is displayed.
2288 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2289 show print entry-values
2290 Set printing of frame argument values at function entry. In some cases
2291 GDB can determine the value of function argument which was passed by the
2292 function caller, even if the value was modified inside the called function.
2294 set debug entry-values
2295 show debug entry-values
2296 Control display of debugging info for determining frame argument values at
2297 function entry and virtual tail call frames.
2299 set basenames-may-differ
2300 show basenames-may-differ
2301 Set whether a source file may have multiple base names.
2302 (A "base name" is the name of a file with the directory part removed.
2303 Example: The base name of "/home/user/hello.c" is "hello.c".)
2304 If set, GDB will canonicalize file names (e.g., expand symlinks)
2305 before comparing them. Canonicalization is an expensive operation,
2306 but it allows the same file be known by more than one base name.
2307 If not set (the default), all source files are assumed to have just
2308 one base name, and gdb will do file name comparisons more efficiently.
2314 Set a user name and notes for the current and any future trace runs.
2315 This is useful for long-running and/or disconnected traces, to
2316 inform others (or yourself) as to who is running the trace, supply
2317 contact information, or otherwise explain what is going on.
2319 set trace-stop-notes
2320 show trace-stop-notes
2321 Set a note attached to the trace run, that is displayed when the
2322 trace has been stopped by a tstop command. This is useful for
2323 instance as an explanation, if you are stopping a trace run that was
2324 started by someone else.
2326 * New remote packets
2330 Dynamically enable a tracepoint in a started trace experiment.
2334 Dynamically disable a tracepoint in a started trace experiment.
2338 Set the user and notes of the trace run.
2342 Query the current status of a tracepoint.
2346 Query the minimum length of instruction at which a fast tracepoint may
2349 * Dcache size (number of lines) and line-size are now runtime-configurable
2350 via "set dcache line" and "set dcache line-size" commands.
2354 Texas Instruments TMS320C6x tic6x-*-*
2358 Renesas RL78 rl78-*-elf
2360 *** Changes in GDB 7.3.1
2362 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2364 *** Changes in GDB 7.3
2366 * GDB has a new command: "thread find [REGEXP]".
2367 It finds the thread id whose name, target id, or thread extra info
2368 matches the given regular expression.
2370 * The "catch syscall" command now works on mips*-linux* targets.
2372 * The -data-disassemble MI command now supports modes 2 and 3 for
2373 dumping the instruction opcodes.
2375 * New command line options
2377 -data-directory DIR Specify DIR as the "data-directory".
2378 This is mostly for testing purposes.
2380 * The "maint set python auto-load on|off" command has been renamed to
2381 "set auto-load-scripts on|off".
2383 * GDB has a new command: "set directories".
2384 It is like the "dir" command except that it replaces the
2385 source path list instead of augmenting it.
2387 * GDB now understands thread names.
2389 On GNU/Linux, "info threads" will display the thread name as set by
2390 prctl or pthread_setname_np.
2392 There is also a new command, "thread name", which can be used to
2393 assign a name internally for GDB to display.
2396 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2397 has been integrated into GDB.
2401 ** The function gdb.Write now accepts an optional keyword 'stream'.
2402 This keyword, when provided, will direct the output to either
2403 stdout, stderr, or GDB's logging output.
2405 ** Parameters can now be be sub-classed in Python, and in particular
2406 you may implement the get_set_doc and get_show_doc functions.
2407 This improves how Parameter set/show documentation is processed
2408 and allows for more dynamic content.
2410 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2411 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2412 have an is_valid method.
2414 ** Breakpoints can now be sub-classed in Python, and in particular
2415 you may implement a 'stop' function that is executed each time
2416 the inferior reaches that breakpoint.
2418 ** New function gdb.lookup_global_symbol looks up a global symbol.
2420 ** GDB values in Python are now callable if the value represents a
2421 function. For example, if 'some_value' represents a function that
2422 takes two integer parameters and returns a value, you can call
2423 that function like so:
2425 result = some_value (10,20)
2427 ** Module gdb.types has been added.
2428 It contains a collection of utilities for working with gdb.Types objects:
2429 get_basic_type, has_field, make_enum_dict.
2431 ** Module gdb.printing has been added.
2432 It contains utilities for writing and registering pretty-printers.
2433 New classes: PrettyPrinter, SubPrettyPrinter,
2434 RegexpCollectionPrettyPrinter.
2435 New function: register_pretty_printer.
2437 ** New commands "info pretty-printers", "enable pretty-printer" and
2438 "disable pretty-printer" have been added.
2440 ** gdb.parameter("directories") is now available.
2442 ** New function gdb.newest_frame returns the newest frame in the
2445 ** The gdb.InferiorThread class has a new "name" attribute. This
2446 holds the thread's name.
2448 ** Python Support for Inferior events.
2449 Python scripts can add observers to be notified of events
2450 occurring in the process being debugged.
2451 The following events are currently supported:
2452 - gdb.events.cont Continue event.
2453 - gdb.events.exited Inferior exited event.
2454 - gdb.events.stop Signal received, and Breakpoint hit events.
2458 ** GDB now puts template parameters in scope when debugging in an
2459 instantiation. For example, if you have:
2461 template<int X> int func (void) { return X; }
2463 then if you step into func<5>, "print X" will show "5". This
2464 feature requires proper debuginfo support from the compiler; it
2465 was added to GCC 4.5.
2467 ** The motion commands "next", "finish", "until", and "advance" now
2468 work better when exceptions are thrown. In particular, GDB will
2469 no longer lose control of the inferior; instead, the GDB will
2470 stop the inferior at the point at which the exception is caught.
2471 This functionality requires a change in the exception handling
2472 code that was introduced in GCC 4.5.
2474 * GDB now follows GCC's rules on accessing volatile objects when
2475 reading or writing target state during expression evaluation.
2476 One notable difference to prior behavior is that "print x = 0"
2477 no longer generates a read of x; the value of the assignment is
2478 now always taken directly from the value being assigned.
2480 * GDB now has some support for using labels in the program's source in
2481 linespecs. For instance, you can use "advance label" to continue
2482 execution to a label.
2484 * GDB now has support for reading and writing a new .gdb_index
2485 section. This section holds a fast index of DWARF debugging
2486 information and can be used to greatly speed up GDB startup and
2487 operation. See the documentation for `save gdb-index' for details.
2489 * The "watch" command now accepts an optional "-location" argument.
2490 When used, this causes GDB to watch the memory referred to by the
2491 expression. Such a watchpoint is never deleted due to it going out
2494 * GDB now supports thread debugging of core dumps on GNU/Linux.
2496 GDB now activates thread debugging using the libthread_db library
2497 when debugging GNU/Linux core dumps, similarly to when debugging
2498 live processes. As a result, when debugging a core dump file, GDB
2499 is now able to display pthread_t ids of threads. For example, "info
2500 threads" shows the same output as when debugging the process when it
2501 was live. In earlier releases, you'd see something like this:
2504 * 1 LWP 6780 main () at main.c:10
2506 While now you see this:
2509 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2511 It is also now possible to inspect TLS variables when debugging core
2514 When debugging a core dump generated on a machine other than the one
2515 used to run GDB, you may need to point GDB at the correct
2516 libthread_db library with the "set libthread-db-search-path"
2517 command. See the user manual for more details on this command.
2519 * When natively debugging programs on PowerPC BookE processors running
2520 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2521 which stop execution of the inferior whenever it executes an instruction
2522 at any address within the specified range. See the "PowerPC Embedded"
2523 section in the user manual for more details.
2525 * New features in the GDB remote stub, GDBserver
2527 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2528 and i686 LynxOS (version 5.x).
2530 ** GDBserver is now supported on Blackfin Linux.
2532 * New native configurations
2534 ia64 HP-UX ia64-*-hpux*
2538 Analog Devices, Inc. Blackfin Processor bfin-*
2540 * Ada task switching is now supported on sparc-elf targets when
2541 debugging a program using the Ravenscar Profile. For more information,
2542 see the "Tasking Support when using the Ravenscar Profile" section
2543 in the GDB user manual.
2545 * Guile support was removed.
2547 * New features in the GNU simulator
2549 ** The --map-info flag lists all known core mappings.
2551 ** CFI flashes may be simulated via the "cfi" device.
2553 *** Changes in GDB 7.2
2555 * Shared library support for remote targets by default
2557 When GDB is configured for a generic, non-OS specific target, like
2558 for example, --target=arm-eabi or one of the many *-*-elf targets,
2559 GDB now queries remote stubs for loaded shared libraries using the
2560 `qXfer:libraries:read' packet. Previously, shared library support
2561 was always disabled for such configurations.
2565 ** Argument Dependent Lookup (ADL)
2567 In C++ ADL lookup directs function search to the namespaces of its
2568 arguments even if the namespace has not been imported.
2578 Here the compiler will search for `foo' in the namespace of 'b'
2579 and find A::foo. GDB now supports this. This construct is commonly
2580 used in the Standard Template Library for operators.
2582 ** Improved User Defined Operator Support
2584 In addition to member operators, GDB now supports lookup of operators
2585 defined in a namespace and imported with a `using' directive, operators
2586 defined in the global scope, operators imported implicitly from an
2587 anonymous namespace, and the ADL operators mentioned in the previous
2589 GDB now also supports proper overload resolution for all the previously
2590 mentioned flavors of operators.
2592 ** static const class members
2594 Printing of static const class members that are initialized in the
2595 class definition has been fixed.
2597 * Windows Thread Information Block access.
2599 On Windows targets, GDB now supports displaying the Windows Thread
2600 Information Block (TIB) structure. This structure is visible either
2601 by using the new command `info w32 thread-information-block' or, by
2602 dereferencing the new convenience variable named `$_tlb', a
2603 thread-specific pointer to the TIB. This feature is also supported
2604 when remote debugging using GDBserver.
2606 * Static tracepoints
2608 Static tracepoints are calls in the user program into a tracing
2609 library. One such library is a port of the LTTng kernel tracer to
2610 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2611 When debugging with GDBserver, GDB now supports combining the GDB
2612 tracepoint machinery with such libraries. For example: the user can
2613 use GDB to probe a static tracepoint marker (a call from the user
2614 program into the tracing library) with the new "strace" command (see
2615 "New commands" below). This creates a "static tracepoint" in the
2616 breakpoint list, that can be manipulated with the same feature set
2617 as fast and regular tracepoints. E.g., collect registers, local and
2618 global variables, collect trace state variables, and define
2619 tracepoint conditions. In addition, the user can collect extra
2620 static tracepoint marker specific data, by collecting the new
2621 $_sdata internal variable. When analyzing the trace buffer, you can
2622 inspect $_sdata like any other variable available to GDB. For more
2623 information, see the "Tracepoints" chapter in GDB user manual. New
2624 remote packets have been defined to support static tracepoints, see
2625 the "New remote packets" section below.
2627 * Better reconstruction of tracepoints after disconnected tracing
2629 GDB will attempt to download the original source form of tracepoint
2630 definitions when starting a trace run, and then will upload these
2631 upon reconnection to the target, resulting in a more accurate
2632 reconstruction of the tracepoints that are in use on the target.
2636 You can now exercise direct control over the ways that GDB can
2637 affect your program. For instance, you can disallow the setting of
2638 breakpoints, so that the program can run continuously (assuming
2639 non-stop mode). In addition, the "observer" variable is available
2640 to switch all of the different controls; in observer mode, GDB
2641 cannot affect the target's behavior at all, which is useful for
2642 tasks like diagnosing live systems in the field.
2644 * The new convenience variable $_thread holds the number of the
2647 * New remote packets
2651 Return the address of the Windows Thread Information Block of a given thread.
2655 In response to several of the tracepoint packets, the target may now
2656 also respond with a number of intermediate `qRelocInsn' request
2657 packets before the final result packet, to have GDB handle
2658 relocating an instruction to execute at a different address. This
2659 is particularly useful for stubs that support fast tracepoints. GDB
2660 reports support for this feature in the qSupported packet.
2664 List static tracepoint markers in the target program.
2668 List static tracepoint markers at a given address in the target
2671 qXfer:statictrace:read
2673 Read the static trace data collected (by a `collect $_sdata'
2674 tracepoint action). The remote stub reports support for this packet
2675 to gdb's qSupported query.
2679 Send the current settings of GDB's permission flags.
2683 Send part of the source (textual) form of a tracepoint definition,
2684 which includes location, conditional, and action list.
2686 * The source command now accepts a -s option to force searching for the
2687 script in the source search path even if the script name specifies
2690 * New features in the GDB remote stub, GDBserver
2692 - GDBserver now support tracepoints (including fast tracepoints, and
2693 static tracepoints). The feature is currently supported by the
2694 i386-linux and amd64-linux builds. See the "Tracepoints support
2695 in gdbserver" section in the manual for more information.
2697 GDBserver JIT compiles the tracepoint's conditional agent
2698 expression bytecode into native code whenever possible for low
2699 overhead dynamic tracepoints conditionals. For such tracepoints,
2700 an expression that examines program state is evaluated when the
2701 tracepoint is reached, in order to determine whether to capture
2702 trace data. If the condition is simple and false, processing the
2703 tracepoint finishes very quickly and no data is gathered.
2705 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2706 for static tracepoints support.
2708 - GDBserver now supports x86_64 Windows 64-bit debugging.
2710 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2711 it understands register description.
2713 * The --batch flag now disables pagination and queries.
2715 * X86 general purpose registers
2717 GDB now supports reading/writing byte, word and double-word x86
2718 general purpose registers directly. This means you can use, say,
2719 $ah or $ax to refer, respectively, to the byte register AH and
2720 16-bit word register AX that are actually portions of the 32-bit
2721 register EAX or 64-bit register RAX.
2723 * The `commands' command now accepts a range of breakpoints to modify.
2724 A plain `commands' following a command that creates multiple
2725 breakpoints affects all the breakpoints set by that command. This
2726 applies to breakpoints set by `rbreak', and also applies when a
2727 single `break' command creates multiple breakpoints (e.g.,
2728 breakpoints on overloaded c++ functions).
2730 * The `rbreak' command now accepts a filename specification as part of
2731 its argument, limiting the functions selected by the regex to those
2732 in the specified file.
2734 * Support for remote debugging Windows and SymbianOS shared libraries
2735 from Unix hosts has been improved. Non Windows GDB builds now can
2736 understand target reported file names that follow MS-DOS based file
2737 system semantics, such as file names that include drive letters and
2738 use the backslash character as directory separator. This makes it
2739 possible to transparently use the "set sysroot" and "set
2740 solib-search-path" on Unix hosts to point as host copies of the
2741 target's shared libraries. See the new command "set
2742 target-file-system-kind" described below, and the "Commands to
2743 specify files" section in the user manual for more information.
2747 eval template, expressions...
2748 Convert the values of one or more expressions under the control
2749 of the string template to a command line, and call it.
2751 set target-file-system-kind unix|dos-based|auto
2752 show target-file-system-kind
2753 Set or show the assumed file system kind for target reported file
2756 save breakpoints <filename>
2757 Save all current breakpoint definitions to a file suitable for use
2758 in a later debugging session. To read the saved breakpoint
2759 definitions, use the `source' command.
2761 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2764 info static-tracepoint-markers
2765 Display information about static tracepoint markers in the target.
2767 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2768 Define a static tracepoint by probing a marker at the given
2769 function, line, address, or marker ID.
2773 Enable and disable observer mode.
2775 set may-write-registers on|off
2776 set may-write-memory on|off
2777 set may-insert-breakpoints on|off
2778 set may-insert-tracepoints on|off
2779 set may-insert-fast-tracepoints on|off
2780 set may-interrupt on|off
2781 Set individual permissions for GDB effects on the target. Note that
2782 some of these settings can have undesirable or surprising
2783 consequences, particularly when changed in the middle of a session.
2784 For instance, disabling the writing of memory can prevent
2785 breakpoints from being inserted, cause single-stepping to fail, or
2786 even crash your program, if you disable after breakpoints have been
2787 inserted. However, GDB should not crash.
2789 set record memory-query on|off
2790 show record memory-query
2791 Control whether to stop the inferior if memory changes caused
2792 by an instruction cannot be recorded.
2797 The disassemble command now supports "start,+length" form of two arguments.
2801 ** GDB now provides a new directory location, called the python directory,
2802 where Python scripts written for GDB can be installed. The location
2803 of that directory is <data-directory>/python, where <data-directory>
2804 is the GDB data directory. For more details, see section `Scripting
2805 GDB using Python' in the manual.
2807 ** The GDB Python API now has access to breakpoints, symbols, symbol
2808 tables, program spaces, inferiors, threads and frame's code blocks.
2809 Additionally, GDB Parameters can now be created from the API, and
2810 manipulated via set/show in the CLI.
2812 ** New functions gdb.target_charset, gdb.target_wide_charset,
2813 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2815 ** New exception gdb.GdbError.
2817 ** Pretty-printers are now also looked up in the current program space.
2819 ** Pretty-printers can now be individually enabled and disabled.
2821 ** GDB now looks for names of Python scripts to auto-load in a
2822 special section named `.debug_gdb_scripts', in addition to looking
2823 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2825 * Tracepoint actions were unified with breakpoint commands. In particular,
2826 there are no longer differences in "info break" output for breakpoints and
2827 tracepoints and the "commands" command can be used for both tracepoints and
2828 regular breakpoints.
2832 ARM Symbian arm*-*-symbianelf*
2834 * D language support.
2835 GDB now supports debugging programs written in the D programming
2838 * GDB now supports the extended ptrace interface for PowerPC which is
2839 available since Linux kernel version 2.6.34. This automatically enables
2840 any hardware breakpoints and additional hardware watchpoints available in
2841 the processor. The old ptrace interface exposes just one hardware
2842 watchpoint and no hardware breakpoints.
2844 * GDB is now able to use the Data Value Compare (DVC) register available on
2845 embedded PowerPC processors to implement in hardware simple watchpoint
2846 conditions of the form:
2848 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2850 This works in native GDB running on Linux kernels with the extended ptrace
2851 interface mentioned above.
2853 *** Changes in GDB 7.1
2857 ** Namespace Support
2859 GDB now supports importing of namespaces in C++. This enables the
2860 user to inspect variables from imported namespaces. Support for
2861 namepace aliasing has also been added. So, if a namespace is
2862 aliased in the current scope (e.g. namepace C=A; ) the user can
2863 print variables using the alias (e.g. (gdb) print C::x).
2867 All known bugs relating to the printing of virtual base class were
2868 fixed. It is now possible to call overloaded static methods using a
2873 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2874 and reinterpret_cast<> are now handled by the C++ expression parser.
2878 Xilinx MicroBlaze microblaze-*-*
2883 Xilinx MicroBlaze microblaze
2886 * Multi-program debugging.
2888 GDB now has support for multi-program (a.k.a. multi-executable or
2889 multi-exec) debugging. This allows for debugging multiple inferiors
2890 simultaneously each running a different program under the same GDB
2891 session. See "Debugging Multiple Inferiors and Programs" in the
2892 manual for more information. This implied some user visible changes
2893 in the multi-inferior support. For example, "info inferiors" now
2894 lists inferiors that are not running yet or that have exited
2895 already. See also "New commands" and "New options" below.
2897 * New tracing features
2899 GDB's tracepoint facility now includes several new features:
2901 ** Trace state variables
2903 GDB tracepoints now include support for trace state variables, which
2904 are variables managed by the target agent during a tracing
2905 experiment. They are useful for tracepoints that trigger each
2906 other, so for instance one tracepoint can count hits in a variable,
2907 and then a second tracepoint has a condition that is true when the
2908 count reaches a particular value. Trace state variables share the
2909 $-syntax of GDB convenience variables, and can appear in both
2910 tracepoint actions and condition expressions. Use the "tvariable"
2911 command to create, and "info tvariables" to view; see "Trace State
2912 Variables" in the manual for more detail.
2916 GDB now includes an option for defining fast tracepoints, which
2917 targets may implement more efficiently, such as by installing a jump
2918 into the target agent rather than a trap instruction. The resulting
2919 speedup can be by two orders of magnitude or more, although the
2920 tradeoff is that some program locations on some target architectures
2921 might not allow fast tracepoint installation, for instance if the
2922 instruction to be replaced is shorter than the jump. To request a
2923 fast tracepoint, use the "ftrace" command, with syntax identical to
2924 the regular trace command.
2926 ** Disconnected tracing
2928 It is now possible to detach GDB from the target while it is running
2929 a trace experiment, then reconnect later to see how the experiment
2930 is going. In addition, a new variable disconnected-tracing lets you
2931 tell the target agent whether to continue running a trace if the
2932 connection is lost unexpectedly.
2936 GDB now has the ability to save the trace buffer into a file, and
2937 then use that file as a target, similarly to you can do with
2938 corefiles. You can select trace frames, print data that was
2939 collected in them, and use tstatus to display the state of the
2940 tracing run at the moment that it was saved. To create a trace
2941 file, use "tsave <filename>", and to use it, do "target tfile
2944 ** Circular trace buffer
2946 You can ask the target agent to handle the trace buffer as a
2947 circular buffer, discarding the oldest trace frames to make room for
2948 newer ones, by setting circular-trace-buffer to on. This feature may
2949 not be available for all target agents.
2954 The disassemble command, when invoked with two arguments, now requires
2955 the arguments to be comma-separated.
2958 The info variables command now displays variable definitions. Files
2959 which only declare a variable are not shown.
2962 The source command is now capable of sourcing Python scripts.
2963 This feature is dependent on the debugger being build with Python
2966 Related to this enhancement is also the introduction of a new command
2967 "set script-extension" (see below).
2969 * New commands (for set/show, see "New options" below)
2971 record save [<FILENAME>]
2972 Save a file (in core file format) containing the process record
2973 execution log for replay debugging at a later time.
2975 record restore <FILENAME>
2976 Restore the process record execution log that was saved at an
2977 earlier time, for replay debugging.
2979 add-inferior [-copies <N>] [-exec <FILENAME>]
2982 clone-inferior [-copies <N>] [ID]
2983 Make a new inferior ready to execute the same program another
2984 inferior has loaded.
2989 maint info program-spaces
2990 List the program spaces loaded into GDB.
2992 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2993 show remote interrupt-sequence
2994 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2995 as the sequence to the remote target in order to interrupt the execution.
2996 Ctrl-C is a default. Some system prefers BREAK which is high level of
2997 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2998 Magic SysRq g. It is BREAK signal and character 'g'.
3000 set remote interrupt-on-connect [on | off]
3001 show remote interrupt-on-connect
3002 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3003 remote target when gdb connects to it. This is needed when you debug
3006 set remotebreak [on | off]
3008 Deprecated. Use "set/show remote interrupt-sequence" instead.
3010 tvariable $NAME [ = EXP ]
3011 Create or modify a trace state variable.
3014 List trace state variables and their values.
3016 delete tvariable $NAME ...
3017 Delete one or more trace state variables.
3020 Evaluate the given expressions without collecting anything into the
3021 trace buffer. (Valid in tracepoint actions only.)
3023 ftrace FN / FILE:LINE / *ADDR
3024 Define a fast tracepoint at the given function, line, or address.
3026 * New expression syntax
3028 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3029 GDB now parses 0b101010 identically with 42.
3033 set follow-exec-mode new|same
3034 show follow-exec-mode
3035 Control whether GDB reuses the same inferior across an exec call or
3036 creates a new one. This is useful to be able to restart the old
3037 executable after the inferior having done an exec call.
3039 set default-collect EXPR, ...
3040 show default-collect
3041 Define a list of expressions to be collected at each tracepoint.
3042 This is a useful way to ensure essential items are not overlooked,
3043 such as registers or a critical global variable.
3045 set disconnected-tracing
3046 show disconnected-tracing
3047 If set to 1, the target is instructed to continue tracing if it
3048 loses its connection to GDB. If 0, the target is to stop tracing
3051 set circular-trace-buffer
3052 show circular-trace-buffer
3053 If set to on, the target is instructed to use a circular trace buffer
3054 and discard the oldest trace frames instead of stopping the trace due
3055 to a full trace buffer. If set to off, the trace stops when the buffer
3056 fills up. Some targets may not support this.
3058 set script-extension off|soft|strict
3059 show script-extension
3060 If set to "off", the debugger does not perform any script language
3061 recognition, and all sourced files are assumed to be GDB scripts.
3062 If set to "soft" (the default), files are sourced according to
3063 filename extension, falling back to GDB scripts if the first
3065 If set to "strict", files are sourced according to filename extension.
3067 set ada trust-PAD-over-XVS on|off
3068 show ada trust-PAD-over-XVS
3069 If off, activate a workaround against a bug in the debugging information
3070 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3071 the GCC sources for more information about the GNAT encoding and
3072 PAD types in particular). It is always safe to set this option to
3073 off, but this introduces a slight performance penalty. The default
3076 * Python API Improvements
3078 ** GDB provides the new class gdb.LazyString. This is useful in
3079 some pretty-printing cases. The new method gdb.Value.lazy_string
3080 provides a simple way to create objects of this type.
3082 ** The fields returned by gdb.Type.fields now have an
3083 `is_base_class' attribute.
3085 ** The new method gdb.Type.range returns the range of an array type.
3087 ** The new method gdb.parse_and_eval can be used to parse and
3088 evaluate an expression.
3090 * New remote packets
3093 Define a trace state variable.
3096 Get the current value of a trace state variable.
3099 Set desired tracing behavior upon disconnection.
3102 Set the trace buffer to be linear or circular.
3105 Get data about the tracepoints currently in use.
3109 Process record now works correctly with hardware watchpoints.
3111 Multiple bug fixes have been made to the mips-irix port, making it
3112 much more reliable. In particular:
3113 - Debugging threaded applications is now possible again. Previously,
3114 GDB would hang while starting the program, or while waiting for
3115 the program to stop at a breakpoint.
3116 - Attaching to a running process no longer hangs.
3117 - An error occurring while loading a core file has been fixed.
3118 - Changing the value of the PC register now works again. This fixes
3119 problems observed when using the "jump" command, or when calling
3120 a function from GDB, or even when assigning a new value to $pc.
3121 - With the "finish" and "return" commands, the return value for functions
3122 returning a small array is now correctly printed.
3123 - It is now possible to break on shared library code which gets executed
3124 during a shared library init phase (code executed while executing
3125 their .init section). Previously, the breakpoint would have no effect.
3126 - GDB is now able to backtrace through the signal handler for
3127 non-threaded programs.
3129 PIE (Position Independent Executable) programs debugging is now supported.
3130 This includes debugging execution of PIC (Position Independent Code) shared
3131 libraries although for that, it should be possible to run such libraries as an
3134 *** Changes in GDB 7.0
3136 * GDB now has an interface for JIT compilation. Applications that
3137 dynamically generate code can create symbol files in memory and register
3138 them with GDB. For users, the feature should work transparently, and
3139 for JIT developers, the interface is documented in the GDB manual in the
3140 "JIT Compilation Interface" chapter.
3142 * Tracepoints may now be conditional. The syntax is as for
3143 breakpoints; either an "if" clause appended to the "trace" command,
3144 or the "condition" command is available. GDB sends the condition to
3145 the target for evaluation using the same bytecode format as is used
3146 for tracepoint actions.
3148 * The disassemble command now supports: an optional /r modifier, print the
3149 raw instructions in hex as well as in symbolic form, and an optional /m
3150 modifier to print mixed source+assembly.
3152 * Process record and replay
3154 In a architecture environment that supports ``process record and
3155 replay'', ``process record and replay'' target can record a log of
3156 the process execution, and replay it with both forward and reverse
3159 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3160 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3161 set execution-direction {forward|reverse}, for targets that support
3164 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3165 feature is available with a native GDB running on kernel version
3168 * GDB now has support for multi-byte and wide character sets on the
3169 target. Strings whose character type is wchar_t, char16_t, or
3170 char32_t are now correctly printed. GDB supports wide- and unicode-
3171 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3172 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3173 `printf'. This feature requires iconv to work properly; if your
3174 system does not have a working iconv, GDB can use GNU libiconv. See
3175 the installation instructions for more information.
3177 * GDB now supports automatic retrieval of shared library files from
3178 remote targets. To use this feature, specify a system root that begins
3179 with the `remote:' prefix, either via the `set sysroot' command or via
3180 the `--with-sysroot' configure-time option.
3182 * "info sharedlibrary" now takes an optional regex of libraries to show,
3183 and it now reports if a shared library has no debugging information.
3185 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3186 now complete on file names.
3188 * When completing in expressions, gdb will attempt to limit
3189 completions to allowable structure or union fields, where appropriate.
3190 For instance, consider:
3192 # struct example { int f1; double f2; };
3193 # struct example variable;
3196 If the user types TAB at the end of this command line, the available
3197 completions will be "f1" and "f2".
3199 * Inlined functions are now supported. They show up in backtraces, and
3200 the "step", "next", and "finish" commands handle them automatically.
3202 * GDB now supports the token-splicing (##) and stringification (#)
3203 operators when expanding macros. It also supports variable-arity
3206 * GDB now supports inspecting extra signal information, exported by
3207 the new $_siginfo convenience variable. The feature is currently
3208 implemented on linux ARM, i386 and amd64.
3210 * GDB can now display the VFP floating point registers and NEON vector
3211 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3212 can provide these registers (requires Linux 2.6.30 or later). Remote
3213 and simulator targets may also provide them.
3215 * New remote packets
3218 Search memory for a sequence of bytes.
3221 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3222 operation over reliable transport links. Use of this packet is
3223 controlled by the `set remote noack-packet' command.
3226 Kill the process with the specified process ID. Use this in preference
3227 to `k' when multiprocess protocol extensions are supported.
3230 Obtains additional operating system information
3234 Read or write additional signal information.
3236 * Removed remote protocol undocumented extension
3238 An undocumented extension to the remote protocol's `S' stop reply
3239 packet that permited the stub to pass a process id was removed.
3240 Remote servers should use the `T' stop reply packet instead.
3242 * GDB now supports multiple function calling conventions according to the
3243 DWARF-2 DW_AT_calling_convention function attribute.
3245 * The SH target utilizes the aforementioned change to distinguish between gcc
3246 and Renesas calling convention. It also adds the new CLI commands
3247 `set/show sh calling-convention'.
3249 * GDB can now read compressed debug sections, as produced by GNU gold
3250 with the --compress-debug-sections=zlib flag.
3252 * 64-bit core files are now supported on AIX.
3254 * Thread switching is now supported on Tru64.
3256 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3257 which will be allocated using malloc later in program execution.
3259 * The qXfer:libraries:read remote procotol packet now allows passing a
3260 list of section offsets.
3262 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3263 conditions handling signals delivered during attach or thread creation
3264 have also been fixed.
3266 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3267 From the user's standpoint, all unqualified instances of True and False
3268 are treated as the standard definitions, regardless of context.
3270 * GDB now parses C++ symbol and type names more flexibly. For
3273 template<typename T> class C { };
3276 GDB will now correctly handle all of:
3278 ptype C<char const *>
3279 ptype C<char const*>
3280 ptype C<const char *>
3281 ptype C<const char*>
3283 * New features in the GDB remote stub, gdbserver
3285 - The "--wrapper" command-line argument tells gdbserver to use a
3286 wrapper program to launch programs for debugging.
3288 - On PowerPC and S/390 targets, it is now possible to use a single
3289 gdbserver executable to debug both 32-bit and 64-bit programs.
3290 (This requires gdbserver itself to be built as a 64-bit executable.)
3292 - gdbserver uses the new noack protocol mode for TCP connections to
3293 reduce communications latency, if also supported and enabled in GDB.
3295 - Support for the sparc64-linux-gnu target is now included in
3298 - The amd64-linux build of gdbserver now supports debugging both
3299 32-bit and 64-bit programs.
3301 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3302 now support hardware watchpoints, and will use them automatically
3307 GDB now has support for scripting using Python. Whether this is
3308 available is determined at configure time.
3310 New GDB commands can now be written in Python.
3312 * Ada tasking support
3314 Ada tasks can now be inspected in GDB. The following commands have
3318 Print the list of Ada tasks.
3320 Print detailed information about task number N.
3322 Print the task number of the current task.
3324 Switch the context of debugging to task number N.
3326 * Support for user-defined prefixed commands. The "define" command can
3327 add new commands to existing prefixes, e.g. "target".
3329 * Multi-inferior, multi-process debugging.
3331 GDB now has generalized support for multi-inferior debugging. See
3332 "Debugging Multiple Inferiors" in the manual for more information.
3333 Although availability still depends on target support, the command
3334 set is more uniform now. The GNU/Linux specific multi-forks support
3335 has been migrated to this new framework. This implied some user
3336 visible changes; see "New commands" and also "Removed commands"
3339 * Target descriptions can now describe the target OS ABI. See the
3340 "Target Description Format" section in the user manual for more
3343 * Target descriptions can now describe "compatible" architectures
3344 to indicate that the target can execute applications for a different
3345 architecture in addition to those for the main target architecture.
3346 See the "Target Description Format" section in the user manual for
3349 * Multi-architecture debugging.
3351 GDB now includes general supports for debugging applications on
3352 hybrid systems that use more than one single processor architecture
3353 at the same time. Each such hybrid architecture still requires
3354 specific support to be added. The only hybrid architecture supported
3355 in this version of GDB is the Cell Broadband Engine.
3357 * GDB now supports integrated debugging of Cell/B.E. applications that
3358 use both the PPU and SPU architectures. To enable support for hybrid
3359 Cell/B.E. debugging, you need to configure GDB to support both the
3360 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3361 --enable-targets configure option.
3363 * Non-stop mode debugging.
3365 For some targets, GDB now supports an optional mode of operation in
3366 which you can examine stopped threads while other threads continue
3367 to execute freely. This is referred to as non-stop mode, with the
3368 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3369 section in the user manual for more information.
3371 To be able to support remote non-stop debugging, a remote stub needs
3372 to implement the non-stop mode remote protocol extensions, as
3373 described in the "Remote Non-Stop" section of the user manual. The
3374 GDB remote stub, gdbserver, has been adjusted to support these
3375 extensions on linux targets.
3377 * New commands (for set/show, see "New options" below)
3379 catch syscall [NAME(S) | NUMBER(S)]
3380 Catch system calls. Arguments, which should be names of system
3381 calls or their numbers, mean catch only those syscalls. Without
3382 arguments, every syscall will be caught. When the inferior issues
3383 any of the specified syscalls, GDB will stop and announce the system
3384 call, both when it is called and when its call returns. This
3385 feature is currently available with a native GDB running on the
3386 Linux Kernel, under the following architectures: x86, x86_64,
3387 PowerPC and PowerPC64.
3389 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3391 Search memory for a sequence of bytes.
3393 maint set python print-stack
3394 maint show python print-stack
3395 Show a stack trace when an error is encountered in a Python script.
3398 Invoke CODE by passing it to the Python interpreter.
3403 These allow macros to be defined, undefined, and listed
3407 Show operating system information about processes.
3410 List the inferiors currently under GDB's control.
3413 Switch focus to inferior number NUM.
3416 Detach from inferior number NUM.
3419 Kill inferior number NUM.
3423 set spu stop-on-load
3424 show spu stop-on-load
3425 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3427 set spu auto-flush-cache
3428 show spu auto-flush-cache
3429 Control whether to automatically flush the software-managed cache
3430 during Cell/B.E. debugging.
3432 set sh calling-convention
3433 show sh calling-convention
3434 Control the calling convention used when calling SH target functions.
3437 show debug timestamp
3438 Control display of timestamps with GDB debugging output.
3440 set disassemble-next-line
3441 show disassemble-next-line
3442 Control display of disassembled source lines or instructions when
3445 set remote noack-packet
3446 show remote noack-packet
3447 Set/show the use of remote protocol QStartNoAckMode packet. See above
3448 under "New remote packets."
3450 set remote query-attached-packet
3451 show remote query-attached-packet
3452 Control use of remote protocol `qAttached' (query-attached) packet.
3454 set remote read-siginfo-object
3455 show remote read-siginfo-object
3456 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3459 set remote write-siginfo-object
3460 show remote write-siginfo-object
3461 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3464 set remote reverse-continue
3465 show remote reverse-continue
3466 Control use of remote protocol 'bc' (reverse-continue) packet.
3468 set remote reverse-step
3469 show remote reverse-step
3470 Control use of remote protocol 'bs' (reverse-step) packet.
3472 set displaced-stepping
3473 show displaced-stepping
3474 Control displaced stepping mode. Displaced stepping is a way to
3475 single-step over breakpoints without removing them from the debuggee.
3476 Also known as "out-of-line single-stepping".
3479 show debug displaced
3480 Control display of debugging info for displaced stepping.
3482 maint set internal-error
3483 maint show internal-error
3484 Control what GDB does when an internal error is detected.
3486 maint set internal-warning
3487 maint show internal-warning
3488 Control what GDB does when an internal warning is detected.
3493 Use a wrapper program to launch programs for debugging.
3495 set multiple-symbols (all|ask|cancel)
3496 show multiple-symbols
3497 The value of this variable can be changed to adjust the debugger behavior
3498 when an expression or a breakpoint location contains an ambiguous symbol
3499 name (an overloaded function name, for instance).
3501 set breakpoint always-inserted
3502 show breakpoint always-inserted
3503 Keep breakpoints always inserted in the target, as opposed to inserting
3504 them when resuming the target, and removing them when the target stops.
3505 This option can improve debugger performance on slow remote targets.
3507 set arm fallback-mode (arm|thumb|auto)
3508 show arm fallback-mode
3509 set arm force-mode (arm|thumb|auto)
3511 These commands control how ARM GDB determines whether instructions
3512 are ARM or Thumb. The default for both settings is auto, which uses
3513 the current CPSR value for instructions without symbols; previous
3514 versions of GDB behaved as if "set arm fallback-mode arm".
3516 set disable-randomization
3517 show disable-randomization
3518 Standalone programs run with the virtual address space randomization enabled
3519 by default on some platforms. This option keeps the addresses stable across
3520 multiple debugging sessions.
3524 Control whether other threads are stopped or not when some thread hits
3529 Requests that asynchronous execution is enabled in the target, if available.
3530 In this case, it's possible to resume target in the background, and interact
3531 with GDB while the target is running. "show target-async" displays the
3532 current state of asynchronous execution of the target.
3534 set target-wide-charset
3535 show target-wide-charset
3536 The target-wide-charset is the name of the character set that GDB
3537 uses when printing characters whose type is wchar_t.
3539 set tcp auto-retry (on|off)
3541 set tcp connect-timeout
3542 show tcp connect-timeout
3543 These commands allow GDB to retry failed TCP connections to a remote stub
3544 with a specified timeout period; this is useful if the stub is launched
3545 in parallel with GDB but may not be ready to accept connections immediately.
3547 set libthread-db-search-path
3548 show libthread-db-search-path
3549 Control list of directories which GDB will search for appropriate
3552 set schedule-multiple (on|off)
3553 show schedule-multiple
3554 Allow GDB to resume all threads of all processes or only threads of
3555 the current process.
3559 Use more aggressive caching for accesses to the stack. This improves
3560 performance of remote debugging (particularly backtraces) without
3561 affecting correctness.
3563 set interactive-mode (on|off|auto)
3564 show interactive-mode
3565 Control whether GDB runs in interactive mode (on) or not (off).
3566 When in interactive mode, GDB waits for the user to answer all
3567 queries. Otherwise, GDB does not wait and assumes the default
3568 answer. When set to auto (the default), GDB determines which
3569 mode to use based on the stdin settings.
3574 For program forks, this is replaced by the new more generic `info
3575 inferiors' command. To list checkpoints, you can still use the
3576 `info checkpoints' command, which was an alias for the `info forks'
3580 Replaced by the new `inferior' command. To switch between
3581 checkpoints, you can still use the `restart' command, which was an
3582 alias for the `fork' command.
3585 This is removed, since some targets don't have a notion of
3586 processes. To switch between processes, you can still use the
3587 `inferior' command using GDB's own inferior number.
3590 For program forks, this is replaced by the new more generic `kill
3591 inferior' command. To delete a checkpoint, you can still use the
3592 `delete checkpoint' command, which was an alias for the `delete
3596 For program forks, this is replaced by the new more generic `detach
3597 inferior' command. To detach a checkpoint, you can still use the
3598 `detach checkpoint' command, which was an alias for the `detach
3601 * New native configurations
3603 x86/x86_64 Darwin i[34567]86-*-darwin*
3605 x86_64 MinGW x86_64-*-mingw*
3609 Lattice Mico32 lm32-*
3610 x86 DICOS i[34567]86-*-dicos*
3611 x86_64 DICOS x86_64-*-dicos*
3614 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3615 (mingw32ce) debugging.
3621 These commands were actually not implemented on any target.
3623 *** Changes in GDB 6.8
3625 * New native configurations
3627 NetBSD/hppa hppa*-*netbsd*
3628 Xtensa GNU/Linux xtensa*-*-linux*
3632 NetBSD/hppa hppa*-*-netbsd*
3633 Xtensa GNU/Lunux xtensa*-*-linux*
3635 * Change in command line behavior -- corefiles vs. process ids.
3637 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3638 attaching to process NUMBER fails, GDB no longer attempts to open a
3639 core file named NUMBER. Attaching to a program using the -c option
3640 is no longer supported. Instead, use the '-p' or '--pid' options.
3642 * GDB can now be built as a native debugger for debugging Windows x86
3643 (mingw32) Portable Executable (PE) programs.
3645 * Pending breakpoints no longer change their number when their address
3648 * GDB now supports breakpoints with multiple locations,
3649 including breakpoints on C++ constructors, inside C++ templates,
3650 and in inlined functions.
3652 * GDB's ability to debug optimized code has been improved. GDB more
3653 accurately identifies function bodies and lexical blocks that occupy
3654 more than one contiguous range of addresses.
3656 * Target descriptions can now describe registers for PowerPC.
3658 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3659 registers on PowerPC targets.
3661 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3662 targets even when the libthread_db library is not available.
3664 * The GDB remote stub, gdbserver, now supports the new file transfer
3665 commands (remote put, remote get, and remote delete).
3667 * The GDB remote stub, gdbserver, now supports run and attach in
3668 extended-remote mode.
3670 * hppa*64*-*-hpux11* target broken
3671 The debugger is unable to start a program and fails with the following
3672 error: "Error trying to get information about dynamic linker".
3673 The gdb-6.7 release is also affected.
3675 * GDB now supports the --enable-targets= configure option to allow
3676 building a single GDB executable that supports multiple remote
3677 target architectures.
3679 * GDB now supports debugging C and C++ programs which use the
3680 Decimal Floating Point extension. In addition, the PowerPC target
3681 now has a set of pseudo-registers to inspect decimal float values
3682 stored in two consecutive float registers.
3684 * The -break-insert MI command can optionally create pending
3687 * Improved support for debugging Ada
3688 Many improvements to the Ada language support have been made. These
3690 - Better support for Ada2005 interface types
3691 - Improved handling of arrays and slices in general
3692 - Better support for Taft-amendment types
3693 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3695 - Improved command completion in Ada
3698 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3703 set print frame-arguments (all|scalars|none)
3704 show print frame-arguments
3705 The value of this variable can be changed to control which argument
3706 values should be printed by the debugger when displaying a frame.
3711 Transfer files to and from a remote target, and delete remote files.
3718 Transfer files to and from a remote target, and delete remote files.
3720 * New remote packets
3727 Open, close, read, write, and delete files on the remote system.
3730 Attach to an existing process on the remote system, in extended-remote
3734 Run a new process on the remote system, in extended-remote mode.
3736 *** Changes in GDB 6.7
3738 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3739 bfd, libiberty and opcodes, as revealed by static analysis donated by
3740 Coverity, Inc. (http://scan.coverity.com).
3742 * When looking up multiply-defined global symbols, GDB will now prefer the
3743 symbol definition in the current shared library if it was built using the
3744 -Bsymbolic linker option.
3746 * When the Text User Interface (TUI) is not configured, GDB will now
3747 recognize the -tui command-line option and print a message that the TUI
3750 * The GDB remote stub, gdbserver, now has lower overhead for high
3751 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3753 * GDB for MIPS targets now autodetects whether a remote target provides
3754 32-bit or 64-bit register values.
3756 * Support for C++ member pointers has been improved.
3758 * GDB now understands XML target descriptions, which specify the
3759 target's overall architecture. GDB can read a description from
3760 a local file or over the remote serial protocol.
3762 * Vectors of single-byte data use a new integer type which is not
3763 automatically displayed as character or string data.
3765 * The /s format now works with the print command. It displays
3766 arrays of single-byte integers and pointers to single-byte integers
3769 * Target descriptions can now describe target-specific registers,
3770 for architectures which have implemented the support (currently
3771 only ARM, M68K, and MIPS).
3773 * GDB and the GDB remote stub, gdbserver, now support the XScale
3776 * The GDB remote stub, gdbserver, has been updated to support
3777 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3778 has been rewritten to use the standard GDB remote protocol.
3780 * GDB can now step into C++ functions which are called through thunks.
3782 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3784 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3785 layout. It also supports a TextSeg= and DataSeg= response when only
3786 segment base addresses (rather than offsets) are available.
3788 * The /i format now outputs any trailing branch delay slot instructions
3789 immediately following the last instruction within the count specified.
3791 * The GDB remote protocol "T" stop reply packet now supports a
3792 "library" response. Combined with the new "qXfer:libraries:read"
3793 packet, this response allows GDB to debug shared libraries on targets
3794 where the operating system manages the list of loaded libraries (e.g.
3795 Windows and SymbianOS).
3797 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3798 (DLLs) on Windows and Windows CE targets.
3800 * GDB now supports a faster verification that a .debug file matches its binary
3801 according to its build-id signature, if the signature is present.
3807 Enable or disable hardware flow control (RTS/CTS) on the serial port
3808 when debugging using remote targets.
3810 set mem inaccessible-by-default
3811 show mem inaccessible-by-default
3812 If the target supplies a memory map, for instance via the remote
3813 protocol's "qXfer:memory-map:read" packet, setting this variable
3814 prevents GDB from accessing memory outside the memory map. This
3815 is useful for targets with memory mapped registers or which react
3816 badly to accesses of unmapped address space.
3818 set breakpoint auto-hw
3819 show breakpoint auto-hw
3820 If the target supplies a memory map, for instance via the remote
3821 protocol's "qXfer:memory-map:read" packet, setting this variable
3822 lets GDB use hardware breakpoints automatically for memory regions
3823 where it can not use software breakpoints. This covers both the
3824 "break" command and internal breakpoints used for other commands
3825 including "next" and "finish".
3828 catch exception unhandled
3829 Stop the program execution when Ada exceptions are raised.
3832 Stop the program execution when an Ada assertion failed.
3836 Set an alternate system root for target files. This is a more
3837 general version of "set solib-absolute-prefix", which is now
3838 an alias to "set sysroot".
3841 Provide extended SPU facility status information. This set of
3842 commands is available only when debugging the Cell/B.E. SPU
3845 * New native configurations
3847 OpenBSD/sh sh*-*openbsd*
3850 unset tdesc filename
3852 Use the specified local file as an XML target description, and do
3853 not query the target for its built-in description.
3857 OpenBSD/sh sh*-*-openbsd*
3858 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3859 Toshiba Media Processor mep-elf
3861 * New remote packets
3864 Ignore the specified signals; pass them directly to the debugged program
3865 without stopping other threads or reporting them to GDB.
3867 qXfer:features:read:
3868 Read an XML target description from the target, which describes its
3873 Read or write contents of an spufs file on the target system. These
3874 packets are available only on the Cell/B.E. SPU architecture.
3876 qXfer:libraries:read:
3877 Report the loaded shared libraries. Combined with new "T" packet
3878 response, this packet allows GDB to debug shared libraries on
3879 targets where the operating system manages the list of loaded
3880 libraries (e.g. Windows and SymbianOS).
3884 Support for these obsolete configurations has been removed.
3892 i[34567]86-*-lynxos*
3893 i[34567]86-*-netware*
3894 i[34567]86-*-sco3.2v5*
3895 i[34567]86-*-sco3.2v4*
3897 i[34567]86-*-sysv4.2*
3900 i[34567]86-*-unixware2*
3901 i[34567]86-*-unixware*
3910 * Other removed features
3917 Various m68k-only ROM monitors.
3924 Various Renesas ROM monitors and debugging interfaces for SH and
3929 Support for a Macraigor serial interface to on-chip debugging.
3930 GDB does not directly support the newer parallel or USB
3935 A debug information format. The predecessor to DWARF 2 and
3936 DWARF 3, which are still supported.
3938 Support for the HP aCC compiler on HP-UX/PA-RISC
3940 SOM-encapsulated symbolic debugging information, automatic
3941 invocation of pxdb, and the aCC custom C++ ABI. This does not
3942 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3943 with aCC can still be debugged on an assembly level.
3945 MIPS ".pdr" sections
3947 A MIPS-specific format used to describe stack frame layout
3948 in debugging information.
3952 GDB could work with an older version of Guile to debug
3953 the interpreter and Scheme programs running in it.
3955 set mips stack-arg-size
3956 set mips saved-gpreg-size
3958 Use "set mips abi" to control parameter passing for MIPS.
3960 *** Changes in GDB 6.6
3965 Cell Broadband Engine SPU spu-elf
3967 * GDB can now be configured as a cross-debugger targeting native Windows
3968 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3969 running on a Windows system over TCP/IP to debug Windows programs.
3971 * The GDB remote stub, gdbserver, has been updated to support Windows and
3972 Cygwin debugging. Both single-threaded and multi-threaded programs are
3975 * The "set trust-readonly-sections" command works again. This command was
3976 broken in GDB 6.3, 6.4, and 6.5.
3978 * The "load" command now supports writing to flash memory, if the remote
3979 stub provides the required support.
3981 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3982 longer requires symbolic debug information (e.g. DWARF-2).
3987 unset substitute-path
3988 show substitute-path
3989 Manage a list of substitution rules that GDB uses to rewrite the name
3990 of the directories where the sources are located. This can be useful
3991 for instance when the sources were moved to a different location
3992 between compilation and debugging.
3996 Print each CLI command as it is executed. Each command is prefixed with
3997 a number of `+' symbols representing the nesting depth.
3998 The source command now has a `-v' option to enable the same feature.
4002 The ARM Demon monitor support (RDP protocol, "target rdp").
4004 Kernel Object Display, an embedded debugging feature which only worked with
4005 an obsolete version of Cisco IOS.
4007 The 'set download-write-size' and 'show download-write-size' commands.
4009 * New remote packets
4012 Tell a stub about GDB client features, and request remote target features.
4013 The first feature implemented is PacketSize, which allows the target to
4014 specify the size of packets it can handle - to minimize the number of
4015 packets required and improve performance when connected to a remote
4019 Fetch an OS auxilliary vector from the remote stub. This packet is a
4020 more efficient replacement for qPart:auxv:read.
4022 qXfer:memory-map:read:
4023 Fetch a memory map from the remote stub, including information about
4024 RAM, ROM, and flash memory devices.
4029 Erase and program a flash memory device.
4031 * Removed remote packets
4034 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4035 used it, and only gdbserver implemented it.
4037 *** Changes in GDB 6.5
4041 Renesas M32C/M16C m32c-elf
4043 Morpho Technologies ms1 ms1-elf
4047 init-if-undefined Initialize a convenience variable, but
4048 only if it doesn't already have a value.
4050 The following commands are presently only implemented for native GNU/Linux:
4052 checkpoint Save a snapshot of the program state.
4054 restart <n> Return the program state to a
4055 previously saved state.
4057 info checkpoints List currently saved checkpoints.
4059 delete-checkpoint <n> Delete a previously saved checkpoint.
4061 set|show detach-on-fork Tell gdb whether to detach from a newly
4062 forked process, or to keep debugging it.
4064 info forks List forks of the user program that
4065 are available to be debugged.
4067 fork <n> Switch to debugging one of several
4068 forks of the user program that are
4069 available to be debugged.
4071 delete-fork <n> Delete a fork from the list of forks
4072 that are available to be debugged (and
4073 kill the forked process).
4075 detach-fork <n> Delete a fork from the list of forks
4076 that are available to be debugged (and
4077 allow the process to continue).
4081 Morpho Technologies ms2 ms1-elf
4083 * Improved Windows host support
4085 GDB now builds as a cross debugger hosted on i686-mingw32, including
4086 native console support, and remote communications using either
4087 network sockets or serial ports.
4089 * Improved Modula-2 language support
4091 GDB can now print most types in the Modula-2 syntax. This includes:
4092 basic types, set types, record types, enumerated types, range types,
4093 pointer types and ARRAY types. Procedure var parameters are correctly
4094 printed and hexadecimal addresses and character constants are also
4095 written in the Modula-2 syntax. Best results can be obtained by using
4096 GNU Modula-2 together with the -gdwarf-2 command line option.
4100 The ARM rdi-share module.
4102 The Netware NLM debug server.
4104 *** Changes in GDB 6.4
4106 * New native configurations
4108 OpenBSD/arm arm*-*-openbsd*
4109 OpenBSD/mips64 mips64-*-openbsd*
4113 Morpho Technologies ms1 ms1-elf
4115 * New command line options
4117 --batch-silent As for --batch, but totally silent.
4118 --return-child-result The debugger will exist with the same value
4119 the child (debugged) program exited with.
4120 --eval-command COMMAND, -ex COMMAND
4121 Execute a single GDB CLI command. This may be
4122 specified multiple times and in conjunction
4123 with the --command (-x) option.
4125 * Deprecated commands removed
4127 The following commands, that were deprecated in 2000, have been
4131 set|show arm disassembly-flavor set|show arm disassembler
4132 othernames set arm disassembler
4133 set|show remotedebug set|show debug remote
4134 set|show archdebug set|show debug arch
4135 set|show eventdebug set|show debug event
4138 * New BSD user-level threads support
4140 It is now possible to debug programs using the user-level threads
4141 library on OpenBSD and FreeBSD. Currently supported (target)
4144 FreeBSD/amd64 x86_64-*-freebsd*
4145 FreeBSD/i386 i386-*-freebsd*
4146 OpenBSD/i386 i386-*-openbsd*
4148 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4149 are not yet supported.
4151 * New support for Matsushita MN10300 w/sim added
4152 (Work in progress). mn10300-elf.
4154 * REMOVED configurations and files
4156 VxWorks and the XDR protocol *-*-vxworks
4157 Motorola MCORE mcore-*-*
4158 National Semiconductor NS32000 ns32k-*-*
4160 * New "set print array-indexes" command
4162 After turning this setting "on", GDB prints the index of each element
4163 when displaying arrays. The default is "off" to preserve the previous
4166 * VAX floating point support
4168 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4170 * User-defined command support
4172 In addition to using $arg0..$arg9 for argument passing, it is now possible
4173 to use $argc to determine now many arguments have been passed. See the
4174 section on user-defined commands in the user manual for more information.
4176 *** Changes in GDB 6.3:
4178 * New command line option
4180 GDB now accepts -l followed by a number to set the timeout for remote
4183 * GDB works with GCC -feliminate-dwarf2-dups
4185 GDB now supports a more compact representation of DWARF-2 debug
4186 information using DW_FORM_ref_addr references. These are produced
4187 by GCC with the option -feliminate-dwarf2-dups and also by some
4188 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4189 to use -feliminate-dwarf2-dups.
4191 * Internationalization
4193 When supported by the host system, GDB will be built with
4194 internationalization (libintl). The task of marking up the sources is
4195 continued, we're looking forward to our first translation.
4199 Initial support for debugging programs compiled with the GNAT
4200 implementation of the Ada programming language has been integrated
4201 into GDB. In this release, support is limited to expression evaluation.
4203 * New native configurations
4205 GNU/Linux/m32r m32r-*-linux-gnu
4209 GDB's remote protocol now includes support for the 'p' packet. This
4210 packet is used to fetch individual registers from a remote inferior.
4212 * END-OF-LIFE registers[] compatibility module
4214 GDB's internal register infrastructure has been completely rewritten.
4215 The new infrastructure making possible the implementation of key new
4216 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4219 GDB 6.3 will be the last release to include the the registers[]
4220 compatibility module that allowed out-of-date configurations to
4221 continue to work. This change directly impacts the following
4231 powerpc bdm protocol
4233 Unless there is activity to revive these configurations, they will be
4234 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4236 * OBSOLETE configurations and files
4238 Configurations that have been declared obsolete in this release have
4239 been commented out. Unless there is activity to revive these
4240 configurations, the next release of GDB will have their sources
4241 permanently REMOVED.
4250 *** Changes in GDB 6.2.1:
4252 * MIPS `break main; run' gave an heuristic-fence-post warning
4254 When attempting to run even a simple program, a warning about
4255 heuristic-fence-post being hit would be reported. This problem has
4258 * MIPS IRIX 'long double' crashed GDB
4260 When examining a long double variable, GDB would get a segmentation
4261 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4262 IRIX long double values).
4266 A bug in the VAX stack code was causing problems with the "next"
4267 command. This problem has been fixed.
4269 *** Changes in GDB 6.2:
4271 * Fix for ``many threads''
4273 On GNU/Linux systems that use the NPTL threads library, a program
4274 rapidly creating and deleting threads would confuse GDB leading to the
4277 ptrace: No such process.
4278 thread_db_get_info: cannot get thread info: generic error
4280 This problem has been fixed.
4282 * "-async" and "-noasync" options removed.
4284 Support for the broken "-noasync" option has been removed (it caused
4287 * New ``start'' command.
4289 This command runs the program until the begining of the main procedure.
4291 * New BSD Kernel Data Access Library (libkvm) interface
4293 Using ``target kvm'' it is now possible to debug kernel core dumps and
4294 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4295 platforms. Currently supported (native-only) configurations are:
4297 FreeBSD/amd64 x86_64-*-freebsd*
4298 FreeBSD/i386 i?86-*-freebsd*
4299 NetBSD/i386 i?86-*-netbsd*
4300 NetBSD/m68k m68*-*-netbsd*
4301 NetBSD/sparc sparc-*-netbsd*
4302 OpenBSD/amd64 x86_64-*-openbsd*
4303 OpenBSD/i386 i?86-*-openbsd*
4304 OpenBSD/m68k m68*-openbsd*
4305 OpenBSD/sparc sparc-*-openbsd*
4307 * Signal trampoline code overhauled
4309 Many generic problems with GDB's signal handling code have been fixed.
4310 These include: backtraces through non-contiguous stacks; recognition
4311 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4312 call; backtrace through a signal trampoline; step into and out of
4313 signal handlers; and single-stepping in the signal trampoline.
4315 Please note that kernel bugs are a limiting factor here. These
4316 features have been shown to work on an s390 GNU/Linux system that
4317 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4319 * Cygwin support for DWARF 2 added.
4321 * New native configurations
4323 GNU/Linux/hppa hppa*-*-linux*
4324 OpenBSD/hppa hppa*-*-openbsd*
4325 OpenBSD/m68k m68*-*-openbsd*
4326 OpenBSD/m88k m88*-*-openbsd*
4327 OpenBSD/powerpc powerpc-*-openbsd*
4328 NetBSD/vax vax-*-netbsd*
4329 OpenBSD/vax vax-*-openbsd*
4331 * END-OF-LIFE frame compatibility module
4333 GDB's internal frame infrastructure has been completely rewritten.
4334 The new infrastructure making it possible to support key new features
4335 including DWARF 2 Call Frame Information. To aid in the task of
4336 migrating old configurations to this new infrastructure, a
4337 compatibility module, that allowed old configurations to continue to
4338 work, was also included.
4340 GDB 6.2 will be the last release to include this frame compatibility
4341 module. This change directly impacts the following configurations:
4351 Unless there is activity to revive these configurations, they will be
4352 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4354 * REMOVED configurations and files
4356 Sun 3, running SunOS 3 m68*-*-sunos3*
4357 Sun 3, running SunOS 4 m68*-*-sunos4*
4358 Sun 2, running SunOS 3 m68000-*-sunos3*
4359 Sun 2, running SunOS 4 m68000-*-sunos4*
4360 Motorola 680x0 running LynxOS m68*-*-lynxos*
4361 AT&T 3b1/Unix pc m68*-att-*
4362 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4363 decstation mips-dec-* mips-little-*
4364 riscos mips-*-riscos* mips-*-sysv*
4365 sonymips mips-sony-*
4366 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4368 *** Changes in GDB 6.1.1:
4370 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4372 The TUI (Text-mode User Interface) is now built as part of a default
4373 GDB configuration. It is enabled by either selecting the TUI with the
4374 command line option "-i=tui" or by running the separate "gdbtui"
4375 program. For more information on the TUI, see the manual "Debugging
4378 * Pending breakpoint support (also included in GDB 6.1)
4380 Support has been added to allow you to specify breakpoints in shared
4381 libraries that have not yet been loaded. If a breakpoint location
4382 cannot be found, and the "breakpoint pending" option is set to auto,
4383 GDB queries you if you wish to make the breakpoint pending on a future
4384 shared-library load. If and when GDB resolves the breakpoint symbol,
4385 the pending breakpoint is removed as one or more regular breakpoints
4388 Pending breakpoints are very useful for GCJ Java debugging.
4390 * Fixed ISO-C build problems
4392 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4393 non ISO-C code that stopped them being built using a more strict ISO-C
4394 compiler (e.g., IBM's C compiler).
4396 * Fixed build problem on IRIX 5
4398 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4399 wasn't able to compile compile on an IRIX 5 system.
4401 * Added execute permission to gdb/gdbserver/configure
4403 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4404 permission. This bug would cause configure to fail on a number of
4405 systems (Solaris, IRIX). Ref: server/519.
4407 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4409 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4410 has been updated to use constant array sizes.
4412 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4414 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4415 its generated DWARF Call Frame Info. This encoding was causing GDB to
4416 panic, that panic has been fixed. Ref: gdb/1628.
4418 * Fixed a problem when examining parameters in shared library code.
4420 When examining parameters in optimized shared library code generated
4421 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4422 not available''. GDB now correctly displays the variable's value.
4424 *** Changes in GDB 6.1:
4426 * Removed --with-mmalloc
4428 Support for the mmalloc memory manager has been removed, as it
4429 conflicted with the internal gdb byte cache.
4431 * Changes in AMD64 configurations
4433 The AMD64 target now includes the %cs and %ss registers. As a result
4434 the AMD64 remote protocol has changed; this affects the floating-point
4435 and SSE registers. If you rely on those registers for your debugging,
4436 you should upgrade gdbserver on the remote side.
4438 * Revised SPARC target
4440 The SPARC target has been completely revised, incorporating the
4441 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4442 support for LynxOS and SunOS 4 has been dropped. Calling functions
4443 from within GDB on operating systems with a non-executable stack
4444 (Solaris, OpenBSD) now works.
4448 GDB has a new C++ demangler which does a better job on the mangled
4449 names generated by current versions of g++. It also runs faster, so
4450 with this and other changes gdb should now start faster on large C++
4453 * DWARF 2 Location Expressions
4455 GDB support for location expressions has been extended to support function
4456 arguments and frame bases. Older versions of GDB could crash when they
4459 * C++ nested types and namespaces
4461 GDB's support for nested types and namespaces in C++ has been
4462 improved, especially if you use the DWARF 2 debugging format. (This
4463 is the default for recent versions of GCC on most platforms.)
4464 Specifically, if you have a class "Inner" defined within a class or
4465 namespace "Outer", then GDB realizes that the class's name is
4466 "Outer::Inner", not simply "Inner". This should greatly reduce the
4467 frequency of complaints about not finding RTTI symbols. In addition,
4468 if you are stopped at inside of a function defined within a namespace,
4469 GDB modifies its name lookup accordingly.
4471 * New native configurations
4473 NetBSD/amd64 x86_64-*-netbsd*
4474 OpenBSD/amd64 x86_64-*-openbsd*
4475 OpenBSD/alpha alpha*-*-openbsd*
4476 OpenBSD/sparc sparc-*-openbsd*
4477 OpenBSD/sparc64 sparc64-*-openbsd*
4479 * New debugging protocols
4481 M32R with SDI protocol m32r-*-elf*
4483 * "set prompt-escape-char" command deleted.
4485 The command "set prompt-escape-char" has been deleted. This command,
4486 and its very obscure effet on GDB's prompt, was never documented,
4487 tested, nor mentioned in the NEWS file.
4489 * OBSOLETE configurations and files
4491 Configurations that have been declared obsolete in this release have
4492 been commented out. Unless there is activity to revive these
4493 configurations, the next release of GDB will have their sources
4494 permanently REMOVED.
4496 Sun 3, running SunOS 3 m68*-*-sunos3*
4497 Sun 3, running SunOS 4 m68*-*-sunos4*
4498 Sun 2, running SunOS 3 m68000-*-sunos3*
4499 Sun 2, running SunOS 4 m68000-*-sunos4*
4500 Motorola 680x0 running LynxOS m68*-*-lynxos*
4501 AT&T 3b1/Unix pc m68*-att-*
4502 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4503 decstation mips-dec-* mips-little-*
4504 riscos mips-*-riscos* mips-*-sysv*
4505 sonymips mips-sony-*
4506 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4508 * REMOVED configurations and files
4510 SGI Irix-4.x mips-sgi-irix4 or iris4
4511 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4512 Z8000 simulator z8k-zilog-none or z8ksim
4513 Matsushita MN10200 w/simulator mn10200-*-*
4514 H8/500 simulator h8500-hitachi-hms or h8500hms
4515 HP/PA running BSD hppa*-*-bsd*
4516 HP/PA running OSF/1 hppa*-*-osf*
4517 HP/PA Pro target hppa*-*-pro*
4518 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4519 386BSD i[3456]86-*-bsd*
4520 Sequent family i[3456]86-sequent-sysv4*
4521 i[3456]86-sequent-sysv*
4522 i[3456]86-sequent-bsd*
4523 SPARC running LynxOS sparc-*-lynxos*
4524 SPARC running SunOS 4 sparc-*-sunos4*
4525 Tsqware Sparclet sparclet-*-*
4526 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4528 *** Changes in GDB 6.0:
4532 Support for debugging the Objective-C programming language has been
4533 integrated into GDB.
4535 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4537 DWARF 2's Call Frame Information makes available compiler generated
4538 information that more exactly describes the program's run-time stack.
4539 By using this information, GDB is able to provide more robust stack
4542 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4543 have been updated to use a new backtrace mechanism which includes
4544 DWARF 2 CFI support.
4548 GDB's remote protocol has been extended to include support for hosted
4549 file I/O (where the remote target uses GDB's file system). See GDB's
4550 remote protocol documentation for details.
4552 * All targets using the new architecture framework.
4554 All of GDB's targets have been updated to use the new internal
4555 architecture framework. The way is now open for future GDB releases
4556 to include cross-architecture native debugging support (i386 on amd64,
4559 * GNU/Linux's Thread Local Storage (TLS)
4561 GDB now includes support for for the GNU/Linux implementation of
4562 per-thread variables.
4564 * GNU/Linux's Native POSIX Thread Library (NPTL)
4566 GDB's thread code has been updated to work with either the new
4567 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4569 * Separate debug info.
4571 GDB, in conjunction with BINUTILS, now supports a mechanism for
4572 automatically loading debug information from a separate file. Instead
4573 of shipping full debug and non-debug versions of system libraries,
4574 system integrators can now instead ship just the stripped libraries
4575 and optional debug files.
4577 * DWARF 2 Location Expressions
4579 DWARF 2 Location Expressions allow the compiler to more completely
4580 describe the location of variables (even in optimized code) to the
4583 GDB now includes preliminary support for location expressions (support
4584 for DW_OP_piece is still missing).
4588 A number of long standing bugs that caused GDB to die while starting a
4589 Java application have been fixed. GDB's Java support is now
4590 considered "useable".
4592 * GNU/Linux support for fork, vfork, and exec.
4594 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4595 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4598 * GDB supports logging output to a file
4600 There are two new commands, "set logging" and "show logging", which can be
4601 used to capture GDB's output to a file.
4603 * The meaning of "detach" has changed for gdbserver
4605 The "detach" command will now resume the application, as documented. To
4606 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4609 * d10v, m68hc11 `regs' command deprecated
4611 The `info registers' command has been updated so that it displays the
4612 registers using a format identical to the old `regs' command.
4616 A new command, "maint set profile on/off", has been added. This command can
4617 be used to enable or disable profiling while running GDB, to profile a
4618 session or a set of commands. In addition there is a new configure switch,
4619 "--enable-profiling", which will cause GDB to be compiled with profiling
4620 data, for more informative profiling results.
4622 * Default MI syntax changed to "mi2".
4624 The default MI (machine interface) syntax, enabled by the command line
4625 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4626 "mi1", can be enabled by specifying the option "-i=mi1".
4628 Support for the original "mi0" syntax (included in GDB 5.0) has been
4631 Fix for gdb/192: removed extraneous space when displaying frame level.
4632 Fix for gdb/672: update changelist is now output in mi list format.
4633 Fix for gdb/702: a -var-assign that updates the value now shows up
4634 in a subsequent -var-update.
4636 * New native configurations.
4638 FreeBSD/amd64 x86_64-*-freebsd*
4640 * Multi-arched targets.
4642 HP/PA HPUX11 hppa*-*-hpux*
4643 Renesas M32R/D w/simulator m32r-*-elf*
4645 * OBSOLETE configurations and files
4647 Configurations that have been declared obsolete in this release have
4648 been commented out. Unless there is activity to revive these
4649 configurations, the next release of GDB will have their sources
4650 permanently REMOVED.
4652 Z8000 simulator z8k-zilog-none or z8ksim
4653 Matsushita MN10200 w/simulator mn10200-*-*
4654 H8/500 simulator h8500-hitachi-hms or h8500hms
4655 HP/PA running BSD hppa*-*-bsd*
4656 HP/PA running OSF/1 hppa*-*-osf*
4657 HP/PA Pro target hppa*-*-pro*
4658 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4659 Sequent family i[3456]86-sequent-sysv4*
4660 i[3456]86-sequent-sysv*
4661 i[3456]86-sequent-bsd*
4662 Tsqware Sparclet sparclet-*-*
4663 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4665 * REMOVED configurations and files
4668 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4669 IBM AIX PS/2 i[3456]86-*-aix
4670 i386 running Mach 3.0 i[3456]86-*-mach3*
4671 i386 running Mach i[3456]86-*-mach*
4672 i386 running OSF/1 i[3456]86-*osf1mk*
4673 HP/Apollo 68k Family m68*-apollo*-sysv*,
4675 m68*-hp-bsd*, m68*-hp-hpux*
4676 Argonaut Risc Chip (ARC) arc-*-*
4677 Mitsubishi D30V d30v-*-*
4678 Fujitsu FR30 fr30-*-elf*
4679 OS/9000 i[34]86-*-os9k
4680 I960 with MON960 i960-*-coff
4682 * MIPS $fp behavior changed
4684 The convenience variable $fp, for the MIPS, now consistently returns
4685 the address of the current frame's base. Previously, depending on the
4686 context, $fp could refer to either $sp or the current frame's base
4687 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4688 The GNU Source-Level Debugger''.
4690 *** Changes in GDB 5.3:
4692 * GNU/Linux shared library multi-threaded performance improved.
4694 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4695 `/proc', in preference to `ptrace' for memory reads. This may result
4696 in an improvement in the start-up time of multi-threaded, shared
4697 library applications when run under GDB. One GDB user writes: ``loads
4698 shared libs like mad''.
4700 * ``gdbserver'' now supports multi-threaded applications on some targets
4702 Support for debugging multi-threaded applications which use
4703 the GNU/Linux LinuxThreads package has been added for
4704 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4705 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4707 * GDB now supports C/C++ preprocessor macros.
4709 GDB now expands preprocessor macro invocations in C/C++ expressions,
4710 and provides various commands for showing macro definitions and how
4713 The new command `macro expand EXPRESSION' expands any macro
4714 invocations in expression, and shows the result.
4716 The new command `show macro MACRO-NAME' shows the definition of the
4717 macro named MACRO-NAME, and where it was defined.
4719 Most compilers don't include information about macros in the debugging
4720 information by default. In GCC 3.1, for example, you need to compile
4721 your program with the options `-gdwarf-2 -g3'. If the macro
4722 information is present in the executable, GDB will read it.
4724 * Multi-arched targets.
4726 DEC Alpha (partial) alpha*-*-*
4727 DEC VAX (partial) vax-*-*
4729 National Semiconductor NS32000 (partial) ns32k-*-*
4730 Motorola 68000 (partial) m68k-*-*
4731 Motorola MCORE mcore-*-*
4735 Fujitsu FRV architecture added by Red Hat frv*-*-*
4738 * New native configurations
4740 Alpha NetBSD alpha*-*-netbsd*
4741 SH NetBSD sh*-*-netbsdelf*
4742 MIPS NetBSD mips*-*-netbsd*
4743 UltraSPARC NetBSD sparc64-*-netbsd*
4745 * OBSOLETE configurations and files
4747 Configurations that have been declared obsolete in this release have
4748 been commented out. Unless there is activity to revive these
4749 configurations, the next release of GDB will have their sources
4750 permanently REMOVED.
4752 Mitsubishi D30V d30v-*-*
4753 OS/9000 i[34]86-*-os9k
4754 IBM AIX PS/2 i[3456]86-*-aix
4755 Fujitsu FR30 fr30-*-elf*
4756 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4757 Argonaut Risc Chip (ARC) arc-*-*
4758 i386 running Mach 3.0 i[3456]86-*-mach3*
4759 i386 running Mach i[3456]86-*-mach*
4760 i386 running OSF/1 i[3456]86-*osf1mk*
4761 HP/Apollo 68k Family m68*-apollo*-sysv*,
4763 m68*-hp-bsd*, m68*-hp-hpux*
4764 I960 with MON960 i960-*-coff
4766 * OBSOLETE languages
4768 CHILL, a Pascal like language used by telecommunications companies.
4770 * REMOVED configurations and files
4772 AMD 29k family via UDI a29k-amd-udi, udi29k
4773 A29K VxWorks a29k-*-vxworks
4774 AMD 29000 embedded, using EBMON a29k-none-none
4775 AMD 29000 embedded with COFF a29k-none-coff
4776 AMD 29000 embedded with a.out a29k-none-aout
4778 testsuite/gdb.hp/gdb.threads-hp/ directory
4780 * New command "set max-user-call-depth <nnn>"
4782 This command allows the user to limit the call depth of user-defined
4783 commands. The default is 1024.
4785 * Changes in FreeBSD/i386 native debugging.
4787 Support for the "generate-core-file" has been added.
4789 * New commands "dump", "append", and "restore".
4791 These commands allow data to be copied from target memory
4792 to a bfd-format or binary file (dump and append), and back
4793 from a file into memory (restore).
4795 * Improved "next/step" support on multi-processor Alpha Tru64.
4797 The previous single-step mechanism could cause unpredictable problems,
4798 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4799 of a software single-step mechanism prevents this.
4801 *** Changes in GDB 5.2.1:
4809 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4810 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4811 Fix, by Joel Brobecker imported from mainline.
4813 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4814 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4815 Fix, by Fred Fish, imported from mainline.
4817 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4818 Surprisingly enough, it works now.
4819 By Michal Ludvig, imported from mainline.
4821 i386 hardware watchpoint support:
4822 avoid misses on second run for some targets.
4823 By Pierre Muller, imported from mainline.
4825 *** Changes in GDB 5.2:
4827 * New command "set trust-readonly-sections on[off]".
4829 This command is a hint that tells gdb that read-only sections
4830 really are read-only (ie. that their contents will not change).
4831 In this mode, gdb will go to the object file rather than the
4832 target to read memory from read-only sections (such as ".text").
4833 This can be a significant performance improvement on some
4834 (notably embedded) targets.
4836 * New command "generate-core-file" (or "gcore").
4838 This new gdb command allows the user to drop a core file of the child
4839 process state at any time. So far it's been implemented only for
4840 GNU/Linux and Solaris, but should be relatively easily ported to other
4841 hosts. Argument is core file name (defaults to core.<pid>).
4843 * New command line option
4845 GDB now accepts --pid or -p followed by a process id.
4847 * Change in command line behavior -- corefiles vs. process ids.
4849 There is a subtle behavior in the way in which GDB handles
4850 command line arguments. The first non-flag argument is always
4851 a program to debug, but the second non-flag argument may either
4852 be a corefile or a process id. Previously, GDB would attempt to
4853 open the second argument as a corefile, and if that failed, would
4854 issue a superfluous error message and then attempt to attach it as
4855 a process. Now, if the second argument begins with a non-digit,
4856 it will be treated as a corefile. If it begins with a digit,
4857 GDB will attempt to attach it as a process, and if no such process
4858 is found, will then attempt to open it as a corefile.
4860 * Changes in ARM configurations.
4862 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4863 configuration is fully multi-arch.
4865 * New native configurations
4867 ARM NetBSD arm*-*-netbsd*
4868 x86 OpenBSD i[3456]86-*-openbsd*
4869 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4870 Sparc64 running FreeBSD sparc64-*-freebsd*
4874 Sanyo XStormy16 xstormy16-elf
4876 * OBSOLETE configurations and files
4878 Configurations that have been declared obsolete in this release have
4879 been commented out. Unless there is activity to revive these
4880 configurations, the next release of GDB will have their sources
4881 permanently REMOVED.
4883 AMD 29k family via UDI a29k-amd-udi, udi29k
4884 A29K VxWorks a29k-*-vxworks
4885 AMD 29000 embedded, using EBMON a29k-none-none
4886 AMD 29000 embedded with COFF a29k-none-coff
4887 AMD 29000 embedded with a.out a29k-none-aout
4889 testsuite/gdb.hp/gdb.threads-hp/ directory
4891 * REMOVED configurations and files
4893 TI TMS320C80 tic80-*-*
4895 PowerPC Solaris powerpcle-*-solaris*
4896 PowerPC Windows NT powerpcle-*-cygwin32
4897 PowerPC Netware powerpc-*-netware*
4898 Harris/CXUX m88k m88*-harris-cxux*
4899 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4900 ns32k-utek-sysv* ns32k-utek-*
4901 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4902 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4903 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4904 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4905 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4907 * Changes to command line processing
4909 The new `--args' feature can be used to specify command-line arguments
4910 for the inferior from gdb's command line.
4912 * Changes to key bindings
4914 There is a new `operate-and-get-next' function bound to `C-o'.
4916 *** Changes in GDB 5.1.1
4918 Fix compile problem on DJGPP.
4920 Fix a problem with floating-point registers on the i386 being
4923 Fix to stop GDB crashing on .debug_str debug info.
4925 Numerous documentation fixes.
4927 Numerous testsuite fixes.
4929 *** Changes in GDB 5.1:
4931 * New native configurations
4933 Alpha FreeBSD alpha*-*-freebsd*
4934 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4935 MIPS GNU/Linux mips*-*-linux*
4936 MIPS SGI Irix 6.x mips*-sgi-irix6*
4937 ia64 AIX ia64-*-aix*
4938 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4942 Motorola 68HC11 and 68HC12 m68hc11-elf
4944 UltraSparc running GNU/Linux sparc64-*-linux*
4946 * OBSOLETE configurations and files
4948 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4949 Harris/CXUX m88k m88*-harris-cxux*
4950 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4951 ns32k-utek-sysv* ns32k-utek-*
4952 TI TMS320C80 tic80-*-*
4954 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4955 PowerPC Solaris powerpcle-*-solaris*
4956 PowerPC Windows NT powerpcle-*-cygwin32
4957 PowerPC Netware powerpc-*-netware*
4958 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4959 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4960 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4961 Apple Macintosh (MPW) host N/A
4963 stuff.c (Program to stuff files into a specially prepared space in kdb)
4964 kdb-start.c (Main loop for the standalone kernel debugger)
4966 Configurations that have been declared obsolete in this release have
4967 been commented out. Unless there is activity to revive these
4968 configurations, the next release of GDB will have their sources
4969 permanently REMOVED.
4971 * REMOVED configurations and files
4973 Altos 3068 m68*-altos-*
4974 Convex c1-*-*, c2-*-*
4976 ARM RISCix arm-*-* (as host)
4980 * GDB has been converted to ISO C.
4982 GDB's source code has been converted to ISO C. In particular, the
4983 sources are fully protoized, and rely on standard headers being
4988 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4990 * The MI enabled by default.
4992 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4993 revised and enabled by default. Packages which use GDB as a debugging
4994 engine behind a UI or another front end are encouraged to switch to
4995 using the GDB/MI interface, instead of the old annotations interface
4996 which is now deprecated.
4998 * Support for debugging Pascal programs.
5000 GDB now includes support for debugging Pascal programs. The following
5001 main features are supported:
5003 - Pascal-specific data types such as sets;
5005 - automatic recognition of Pascal sources based on file-name
5008 - Pascal-style display of data types, variables, and functions;
5010 - a Pascal expression parser.
5012 However, some important features are not yet supported.
5014 - Pascal string operations are not supported at all;
5016 - there are some problems with boolean types;
5018 - Pascal type hexadecimal constants are not supported
5019 because they conflict with the internal variables format;
5021 - support for Pascal objects and classes is not full yet;
5023 - unlike Pascal, GDB is case-sensitive for symbol names.
5025 * Changes in completion.
5027 Commands such as `shell', `run' and `set args', which pass arguments
5028 to inferior programs, now complete on file names, similar to what
5029 users expect at the shell prompt.
5031 Commands which accept locations, such as `disassemble', `print',
5032 `breakpoint', `until', etc. now complete on filenames as well as
5033 program symbols. Thus, if you type "break foob TAB", and the source
5034 files linked into the programs include `foobar.c', that file name will
5035 be one of the candidates for completion. However, file names are not
5036 considered for completion after you typed a colon that delimits a file
5037 name from a name of a function in that file, as in "break foo.c:bar".
5039 `set demangle-style' completes on available demangling styles.
5041 * New platform-independent commands:
5043 It is now possible to define a post-hook for a command as well as a
5044 hook that runs before the command. For more details, see the
5045 documentation of `hookpost' in the GDB manual.
5047 * Changes in GNU/Linux native debugging.
5049 Support for debugging multi-threaded programs has been completely
5050 revised for all platforms except m68k and sparc. You can now debug as
5051 many threads as your system allows you to have.
5053 Attach/detach is supported for multi-threaded programs.
5055 Support for SSE registers was added for x86. This doesn't work for
5056 multi-threaded programs though.
5058 * Changes in MIPS configurations.
5060 Multi-arch support is enabled for all MIPS configurations.
5062 GDB can now be built as native debugger on SGI Irix 6.x systems for
5063 debugging n32 executables. (Debugging 64-bit executables is not yet
5066 * Unified support for hardware watchpoints in all x86 configurations.
5068 Most (if not all) native x86 configurations support hardware-assisted
5069 breakpoints and watchpoints in a unified manner. This support
5070 implements debug register sharing between watchpoints, which allows to
5071 put a virtually infinite number of watchpoints on the same address,
5072 and also supports watching regions up to 16 bytes with several debug
5075 The new maintenance command `maintenance show-debug-regs' toggles
5076 debugging print-outs in functions that insert, remove, and test
5077 watchpoints and hardware breakpoints.
5079 * Changes in the DJGPP native configuration.
5081 New command ``info dos sysinfo'' displays assorted information about
5082 the CPU, OS, memory, and DPMI server.
5084 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5085 display information about segment descriptors stored in GDT, LDT, and
5088 New commands ``info dos pde'' and ``info dos pte'' display entries
5089 from Page Directory and Page Tables (for now works with CWSDPMI only).
5090 New command ``info dos address-pte'' displays the Page Table entry for
5091 a given linear address.
5093 GDB can now pass command lines longer than 126 characters to the
5094 program being debugged (requires an update to the libdbg.a library
5095 which is part of the DJGPP development kit).
5097 DWARF2 debug info is now supported.
5099 It is now possible to `step' and `next' through calls to `longjmp'.
5101 * Changes in documentation.
5103 All GDB documentation was converted to GFDL, the GNU Free
5104 Documentation License.
5106 Tracepoints-related commands are now fully documented in the GDB
5109 TUI, the Text-mode User Interface, is now documented in the manual.
5111 Tracepoints-related commands are now fully documented in the GDB
5114 The "GDB Internals" manual now has an index. It also includes
5115 documentation of `ui_out' functions, GDB coding standards, x86
5116 hardware watchpoints, and memory region attributes.
5118 * GDB's version number moved to ``version.in''
5120 The Makefile variable VERSION has been replaced by the file
5121 ``version.in''. People creating GDB distributions should update the
5122 contents of this file.
5126 GUD support is now a standard part of the EMACS distribution.
5128 *** Changes in GDB 5.0:
5130 * Improved support for debugging FP programs on x86 targets
5132 Unified and much-improved support for debugging floating-point
5133 programs on all x86 targets. In particular, ``info float'' now
5134 displays the FP registers in the same format on all x86 targets, with
5135 greater level of detail.
5137 * Improvements and bugfixes in hardware-assisted watchpoints
5139 It is now possible to watch array elements, struct members, and
5140 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5141 on x86 targets no longer erroneously trigger when the address is
5144 * Improvements in the native DJGPP version of GDB
5146 The distribution now includes all the scripts and auxiliary files
5147 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5148 machines ``out of the box''.
5150 The DJGPP version can now debug programs that use signals. It is
5151 possible to catch signals that happened in the debuggee, deliver
5152 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5153 would kill the program being debugged.) Programs that hook hardware
5154 interrupts (keyboard, timer, etc.) can also be debugged.
5156 It is now possible to debug DJGPP programs that redirect their
5157 standard handles or switch them to raw (as opposed to cooked) mode, or
5158 even close them. The command ``run < foo > bar'' works as expected,
5159 and ``info terminal'' reports useful information about the debuggee's
5160 terminal, including raw/cooked mode, redirection, etc.
5162 The DJGPP version now uses termios functions for console I/O, which
5163 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5166 DOS-style file names with drive letters are now fully supported by
5169 It is now possible to debug DJGPP programs that switch their working
5170 directory. It is also possible to rerun the debuggee any number of
5171 times without restarting GDB; thus, you can use the same setup,
5172 breakpoints, etc. for many debugging sessions.
5174 * New native configurations
5176 ARM GNU/Linux arm*-*-linux*
5177 PowerPC GNU/Linux powerpc-*-linux*
5181 Motorola MCore mcore-*-*
5182 x86 VxWorks i[3456]86-*-vxworks*
5183 PowerPC VxWorks powerpc-*-vxworks*
5184 TI TMS320C80 tic80-*-*
5186 * OBSOLETE configurations
5188 Altos 3068 m68*-altos-*
5189 Convex c1-*-*, c2-*-*
5191 ARM RISCix arm-*-* (as host)
5194 Configurations that have been declared obsolete will be commented out,
5195 but the code will be left in place. If there is no activity to revive
5196 these configurations before the next release of GDB, the sources will
5197 be permanently REMOVED.
5199 * Gould support removed
5201 Support for the Gould PowerNode and NP1 has been removed.
5203 * New features for SVR4
5205 On SVR4 native platforms (such as Solaris), if you attach to a process
5206 without first loading a symbol file, GDB will now attempt to locate and
5207 load symbols from the running process's executable file.
5209 * Many C++ enhancements
5211 C++ support has been greatly improved. Overload resolution now works properly
5212 in almost all cases. RTTI support is on the way.
5214 * Remote targets can connect to a sub-program
5216 A popen(3) style serial-device has been added. This device starts a
5217 sub-process (such as a stand-alone simulator) and then communicates
5218 with that. The sub-program to run is specified using the syntax
5219 ``|<program> <args>'' vis:
5221 (gdb) set remotedebug 1
5222 (gdb) target extended-remote |mn10300-elf-sim program-args
5224 * MIPS 64 remote protocol
5226 A long standing bug in the mips64 remote protocol where by GDB
5227 expected certain 32 bit registers (ex SR) to be transfered as 32
5228 instead of 64 bits has been fixed.
5230 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5231 added to provide backward compatibility with older versions of GDB.
5233 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5235 The command ``set remotebinarydownload'' command has been replaced by
5236 ``set remote X-packet''. Other commands in ``set remote'' family
5237 include ``set remote P-packet''.
5239 * Breakpoint commands accept ranges.
5241 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5242 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5243 ``tracepoint passcount'' also accepts a range of tracepoints.
5245 * ``apropos'' command added.
5247 The ``apropos'' command searches through command names and
5248 documentation strings, printing out matches, making it much easier to
5249 try to find a command that does what you are looking for.
5253 A new machine oriented interface (MI) has been added to GDB. This
5254 interface is designed for debug environments running GDB as a separate
5255 process. This is part of the long term libGDB project. See the
5256 "GDB/MI" chapter of the GDB manual for further information. It can be
5257 enabled by configuring with:
5259 .../configure --enable-gdbmi
5261 *** Changes in GDB-4.18:
5263 * New native configurations
5265 HP-UX 10.20 hppa*-*-hpux10.20
5266 HP-UX 11.x hppa*-*-hpux11.0*
5267 M68K GNU/Linux m68*-*-linux*
5271 Fujitsu FR30 fr30-*-elf*
5272 Intel StrongARM strongarm-*-*
5273 Mitsubishi D30V d30v-*-*
5275 * OBSOLETE configurations
5277 Gould PowerNode, NP1 np1-*-*, pn-*-*
5279 Configurations that have been declared obsolete will be commented out,
5280 but the code will be left in place. If there is no activity to revive
5281 these configurations before the next release of GDB, the sources will
5282 be permanently REMOVED.
5286 As a compatibility experiment, GDB's source files buildsym.h and
5287 buildsym.c have been converted to pure standard C, no longer
5288 containing any K&R compatibility code. We believe that all systems in
5289 use today either come with a standard C compiler, or have a GCC port
5290 available. If this is not true, please report the affected
5291 configuration to bug-gdb@gnu.org immediately. See the README file for
5292 information about getting a standard C compiler if you don't have one
5297 GDB now uses readline 2.2.
5299 * set extension-language
5301 You can now control the mapping between filename extensions and source
5302 languages by using the `set extension-language' command. For instance,
5303 you can ask GDB to treat .c files as C++ by saying
5304 set extension-language .c c++
5305 The command `info extensions' lists all of the recognized extensions
5306 and their associated languages.
5308 * Setting processor type for PowerPC and RS/6000
5310 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5311 you can use the `set processor' command to specify what variant of the
5312 PowerPC family you are debugging. The command
5316 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5317 following PowerPC and RS6000 variants:
5319 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5320 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5322 403GC IBM PowerPC 403GC
5323 505 Motorola PowerPC 505
5324 860 Motorola PowerPC 860 or 850
5325 601 Motorola PowerPC 601
5326 602 Motorola PowerPC 602
5327 603 Motorola/IBM PowerPC 603 or 603e
5328 604 Motorola PowerPC 604 or 604e
5329 750 Motorola/IBM PowerPC 750 or 750
5331 At the moment, this command just tells GDB what to name the
5332 special-purpose processor registers. Since almost all the affected
5333 registers are inaccessible to user-level programs, this command is
5334 only useful for remote debugging in its present form.
5338 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5339 more extensive support for HP-UX. Added features include shared
5340 library support, kernel threads and hardware watchpoints for 11.00,
5341 support for HP's ANSI C and C++ compilers, and a compatibility mode
5342 for xdb and dbx commands.
5346 HP's donation includes the new concept of catchpoints, which is a
5347 generalization of the old catch command. On HP-UX, it is now possible
5348 to catch exec, fork, and vfork, as well as library loading.
5350 This means that the existing catch command has changed; its first
5351 argument now specifies the type of catch to be set up. See the
5352 output of "help catch" for a list of catchpoint types.
5354 * Debugging across forks
5356 On HP-UX, you can choose which process to debug when a fork() happens
5361 HP has donated a curses-based terminal user interface (TUI). To get
5362 it, build with --enable-tui. Although this can be enabled for any
5363 configuration, at present it only works for native HP debugging.
5365 * GDB remote protocol additions
5367 A new protocol packet 'X' that writes binary data is now available.
5368 Default behavior is to try 'X', then drop back to 'M' if the stub
5369 fails to respond. The settable variable `remotebinarydownload'
5370 allows explicit control over the use of 'X'.
5372 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5373 full 64-bit address. The command
5375 set remoteaddresssize 32
5377 can be used to revert to the old behaviour. For existing remote stubs
5378 the change should not be noticed, as the additional address information
5381 In order to assist in debugging stubs, you may use the maintenance
5382 command `packet' to send any text string to the stub. For instance,
5384 maint packet heythere
5386 sends the packet "$heythere#<checksum>". Note that it is very easy to
5387 disrupt a debugging session by sending the wrong packet at the wrong
5390 The compare-sections command allows you to compare section data on the
5391 target to what is in the executable file without uploading or
5392 downloading, by comparing CRC checksums.
5394 * Tracing can collect general expressions
5396 You may now collect general expressions at tracepoints. This requires
5397 further additions to the target-side stub; see tracepoint.c and
5398 doc/agentexpr.texi for further details.
5400 * mask-address variable for Mips
5402 For Mips targets, you may control the zeroing of the upper 32 bits of
5403 a 64-bit address by entering `set mask-address on'. This is mainly
5404 of interest to users of embedded R4xxx and R5xxx processors.
5406 * Higher serial baud rates
5408 GDB's serial code now allows you to specify baud rates 57600, 115200,
5409 230400, and 460800 baud. (Note that your host system may not be able
5410 to achieve all of these rates.)
5414 The i960 configuration now includes an initial implementation of a
5415 builtin simulator, contributed by Jim Wilson.
5418 *** Changes in GDB-4.17:
5420 * New native configurations
5422 Alpha GNU/Linux alpha*-*-linux*
5423 Unixware 2.x i[3456]86-unixware2*
5424 Irix 6.x mips*-sgi-irix6*
5425 PowerPC GNU/Linux powerpc-*-linux*
5426 PowerPC Solaris powerpcle-*-solaris*
5427 Sparc GNU/Linux sparc-*-linux*
5428 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5432 Argonaut Risc Chip (ARC) arc-*-*
5433 Hitachi H8/300S h8300*-*-*
5434 Matsushita MN10200 w/simulator mn10200-*-*
5435 Matsushita MN10300 w/simulator mn10300-*-*
5436 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5437 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5438 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5439 Mitsubishi D10V w/simulator d10v-*-*
5440 Mitsubishi M32R/D w/simulator m32r-*-elf*
5441 Tsqware Sparclet sparclet-*-*
5442 NEC V850 w/simulator v850-*-*
5444 * New debugging protocols
5446 ARM with RDI protocol arm*-*-*
5447 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5448 DDB and LSI variants of PMON protocol mips*-*-*
5449 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5450 PowerPC with SDS protocol powerpc{,le}-*-eabi
5451 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5455 All configurations can now understand and use the DWARF 2 debugging
5456 format. The choice is automatic, if the symbol file contains DWARF 2
5461 GDB now includes basic Java language support. This support is
5462 only useful with Java compilers that produce native machine code.
5464 * solib-absolute-prefix and solib-search-path
5466 For SunOS and SVR4 shared libraries, you may now set the prefix for
5467 loading absolute shared library symbol files, and the search path for
5468 locating non-absolute shared library symbol files.
5470 * Live range splitting
5472 GDB can now effectively debug code for which GCC has performed live
5473 range splitting as part of its optimization. See gdb/doc/LRS for
5474 more details on the expected format of the stabs information.
5478 GDB's support for the GNU Hurd, including thread debugging, has been
5479 updated to work with current versions of the Hurd.
5483 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5484 instruction set. ARM GDB automatically detects when Thumb
5485 instructions are in use, and adjusts disassembly and backtracing
5490 GDB's MIPS target configurations now handle the MIP16 16-bit
5495 GDB now includes support for overlays; if an executable has been
5496 linked such that multiple sections are based at the same address, GDB
5497 will decide which section to use for symbolic info. You can choose to
5498 control the decision manually, using overlay commands, or implement
5499 additional target-side support and use "overlay load-target" to bring
5500 in the overlay mapping. Do "help overlay" for more detail.
5504 The command "info symbol <address>" displays information about
5505 the symbol at the specified address.
5509 The standard remote protocol now includes an extension that allows
5510 asynchronous collection and display of trace data. This requires
5511 extensive support in the target-side debugging stub. Tracing mode
5512 includes a new interaction mode in GDB and new commands: see the
5513 file tracepoint.c for more details.
5517 Configurations for embedded MIPS now include a simulator contributed
5518 by Cygnus Solutions. The simulator supports the instruction sets
5519 of most MIPS variants.
5523 Sparc configurations may now include the ERC32 simulator contributed
5524 by the European Space Agency. The simulator is not built into
5525 Sparc targets by default; configure with --enable-sim to include it.
5529 For target configurations that may include multiple variants of a
5530 basic architecture (such as MIPS and SH), you may now set the
5531 architecture explicitly. "set arch" sets, "info arch" lists
5532 the possible architectures.
5534 *** Changes in GDB-4.16:
5536 * New native configurations
5538 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5539 M68K NetBSD m68k-*-netbsd*
5540 PowerPC AIX 4.x powerpc-*-aix*
5541 PowerPC MacOS powerpc-*-macos*
5542 PowerPC Windows NT powerpcle-*-cygwin32
5543 RS/6000 AIX 4.x rs6000-*-aix4*
5547 ARM with RDP protocol arm-*-*
5548 I960 with MON960 i960-*-coff
5549 MIPS VxWorks mips*-*-vxworks*
5550 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5551 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5553 Matra Sparclet sparclet-*-*
5557 The powerpc-eabi configuration now includes the PSIM simulator,
5558 contributed by Andrew Cagney, with assistance from Mike Meissner.
5559 PSIM is a very elaborate model of the PowerPC, including not only
5560 basic instruction set execution, but also details of execution unit
5561 performance and I/O hardware. See sim/ppc/README for more details.
5565 GDB now works with Solaris 2.5.
5567 * Windows 95/NT native
5569 GDB will now work as a native debugger on Windows 95 and Windows NT.
5570 To build it from source, you must use the "gnu-win32" environment,
5571 which uses a DLL to emulate enough of Unix to run the GNU tools.
5572 Further information, binaries, and sources are available at
5573 ftp.cygnus.com, under pub/gnu-win32.
5575 * dont-repeat command
5577 If a user-defined command includes the command `dont-repeat', then the
5578 command will not be repeated if the user just types return. This is
5579 useful if the command is time-consuming to run, so that accidental
5580 extra keystrokes don't run the same command many times.
5582 * Send break instead of ^C
5584 The standard remote protocol now includes an option to send a break
5585 rather than a ^C to the target in order to interrupt it. By default,
5586 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5588 * Remote protocol timeout
5590 The standard remote protocol includes a new variable `remotetimeout'
5591 that allows you to set the number of seconds before GDB gives up trying
5592 to read from the target. The default value is 2.
5594 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5596 By default GDB will automatically keep track of objects as they are
5597 loaded and unloaded by the dynamic linker. By using the command `set
5598 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5599 when shared library events occur, thus allowing you to set breakpoints
5600 in shared libraries which are explicitly loaded by the inferior.
5602 Note this feature does not work on hpux8. On hpux9 you must link
5603 /usr/lib/end.o into your program. This feature should work
5604 automatically on hpux10.
5606 * Irix 5.x hardware watchpoint support
5608 Irix 5 configurations now support the use of hardware watchpoints.
5610 * Mips protocol "SYN garbage limit"
5612 When debugging a Mips target using the `target mips' protocol, you
5613 may set the number of characters that GDB will ignore by setting
5614 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5615 every character. The default value is 1050.
5617 * Recording and replaying remote debug sessions
5619 If you set `remotelogfile' to the name of a file, gdb will write to it
5620 a recording of a remote debug session. This recording may then be
5621 replayed back to gdb using "gdbreplay". See gdbserver/README for
5622 details. This is useful when you have a problem with GDB while doing
5623 remote debugging; you can make a recording of the session and send it
5624 to someone else, who can then recreate the problem.
5626 * Speedups for remote debugging
5628 GDB includes speedups for downloading and stepping MIPS systems using
5629 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5630 and more efficient S-record downloading.
5632 * Memory use reductions and statistics collection
5634 GDB now uses less memory and reports statistics about memory usage.
5635 Try the `maint print statistics' command, for example.
5637 *** Changes in GDB-4.15:
5639 * Psymtabs for XCOFF
5641 The symbol reader for AIX GDB now uses partial symbol tables. This
5642 can greatly improve startup time, especially for large executables.
5644 * Remote targets use caching
5646 Remote targets now use a data cache to speed up communication with the
5647 remote side. The data cache could lead to incorrect results because
5648 it doesn't know about volatile variables, thus making it impossible to
5649 debug targets which use memory mapped I/O devices. `set remotecache
5650 off' turns the the data cache off.
5652 * Remote targets may have threads
5654 The standard remote protocol now includes support for multiple threads
5655 in the target system, using new protocol commands 'H' and 'T'. See
5656 gdb/remote.c for details.
5660 If GDB is configured with `--enable-netrom', then it will include
5661 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5662 acts as though it is a bank of ROM on the target board, but you can
5663 write into it over the network. GDB's support consists only of
5664 support for fast loading into the emulated ROM; to debug, you must use
5665 another protocol, such as standard remote protocol. The usual
5666 sequence is something like
5668 target nrom <netrom-hostname>
5670 target remote <netrom-hostname>:1235
5674 GDB now includes support for the Apple Macintosh, as a host only. It
5675 may be run as either an MPW tool or as a standalone application, and
5676 it can debug through the serial port. All the usual GDB commands are
5677 available, but to the target command, you must supply "serial" as the
5678 device type instead of "/dev/ttyXX". See mpw-README in the main
5679 directory for more information on how to build. The MPW configuration
5680 scripts */mpw-config.in support only a few targets, and only the
5681 mips-idt-ecoff target has been tested.
5685 GDB configuration now uses autoconf. This is not user-visible,
5686 but does simplify configuration and building.
5690 GDB now supports hpux10.
5692 *** Changes in GDB-4.14:
5694 * New native configurations
5696 x86 FreeBSD i[345]86-*-freebsd
5697 x86 NetBSD i[345]86-*-netbsd
5698 NS32k NetBSD ns32k-*-netbsd
5699 Sparc NetBSD sparc-*-netbsd
5703 A29K VxWorks a29k-*-vxworks
5704 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5705 CPU32 EST-300 emulator m68*-*-est*
5706 PowerPC ELF powerpc-*-elf
5709 * Alpha OSF/1 support for procfs
5711 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5712 possible to attach to running processes. As the mounting of the /proc
5713 filesystem is optional on the Alpha, GDB automatically determines
5714 the availability of /proc during startup. This can lead to problems
5715 if /proc is unmounted after GDB has been started.
5717 * Arguments to user-defined commands
5719 User commands may accept up to 10 arguments separated by whitespace.
5720 Arguments are accessed within the user command via $arg0..$arg9. A
5723 print $arg0 + $arg1 + $arg2
5725 To execute the command use:
5728 Defines the command "adder" which prints the sum of its three arguments.
5729 Note the arguments are text substitutions, so they may reference variables,
5730 use complex expressions, or even perform inferior function calls.
5732 * New `if' and `while' commands
5734 This makes it possible to write more sophisticated user-defined
5735 commands. Both commands take a single argument, which is the
5736 expression to evaluate, and must be followed by the commands to
5737 execute, one per line, if the expression is nonzero, the list being
5738 terminated by the word `end'. The `if' command list may include an
5739 `else' word, which causes the following commands to be executed only
5740 if the expression is zero.
5742 * Fortran source language mode
5744 GDB now includes partial support for Fortran 77. It will recognize
5745 Fortran programs and can evaluate a subset of Fortran expressions, but
5746 variables and functions may not be handled correctly. GDB will work
5747 with G77, but does not yet know much about symbols emitted by other
5750 * Better HPUX support
5752 Most debugging facilities now work on dynamic executables for HPPAs
5753 running hpux9 or later. You can attach to running dynamically linked
5754 processes, but by default the dynamic libraries will be read-only, so
5755 for instance you won't be able to put breakpoints in them. To change
5756 that behavior do the following before running the program:
5762 This will cause the libraries to be mapped private and read-write.
5763 To revert to the normal behavior, do this:
5769 You cannot set breakpoints or examine data in the library until after
5770 the library is loaded if the function/data symbols do not have
5773 GDB can now also read debug symbols produced by the HP C compiler on
5774 HPPAs (sorry, no C++, Fortran or 68k support).
5776 * Target byte order now dynamically selectable
5778 You can choose which byte order to use with a target system, via the
5779 commands "set endian big" and "set endian little", and you can see the
5780 current setting by using "show endian". You can also give the command
5781 "set endian auto", in which case GDB will use the byte order
5782 associated with the executable. Currently, only embedded MIPS
5783 configurations support dynamic selection of target byte order.
5785 * New DOS host serial code
5787 This version uses DPMI interrupts to handle buffered I/O, so you
5788 no longer need to run asynctsr when debugging boards connected to
5791 *** Changes in GDB-4.13:
5793 * New "complete" command
5795 This lists all the possible completions for the rest of the line, if it
5796 were to be given as a command itself. This is intended for use by emacs.
5798 * Trailing space optional in prompt
5800 "set prompt" no longer adds a space for you after the prompt you set. This
5801 allows you to set a prompt which ends in a space or one that does not.
5803 * Breakpoint hit counts
5805 "info break" now displays a count of the number of times the breakpoint
5806 has been hit. This is especially useful in conjunction with "ignore"; you
5807 can ignore a large number of breakpoint hits, look at the breakpoint info
5808 to see how many times the breakpoint was hit, then run again, ignoring one
5809 less than that number, and this will get you quickly to the last hit of
5812 * Ability to stop printing at NULL character
5814 "set print null-stop" will cause GDB to stop printing the characters of
5815 an array when the first NULL is encountered. This is useful when large
5816 arrays actually contain only short strings.
5818 * Shared library breakpoints
5820 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5821 breakpoints in shared libraries before the executable is run.
5823 * Hardware watchpoints
5825 There is a new hardware breakpoint for the watch command for sparclite
5826 targets. See gdb/sparclite/hw_breakpoint.note.
5828 Hardware watchpoints are also now supported under GNU/Linux.
5832 Annotations have been added. These are for use with graphical interfaces,
5833 and are still experimental. Currently only gdba.el uses these.
5835 * Improved Irix 5 support
5837 GDB now works properly with Irix 5.2.
5839 * Improved HPPA support
5841 GDB now works properly with the latest GCC and GAS.
5843 * New native configurations
5845 Sequent PTX4 i[34]86-sequent-ptx4
5846 HPPA running OSF/1 hppa*-*-osf*
5847 Atari TT running SVR4 m68*-*-sysv4*
5848 RS/6000 LynxOS rs6000-*-lynxos*
5852 OS/9000 i[34]86-*-os9k
5853 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5856 * Hitachi SH7000 and E7000-PC ICE support
5858 There is now support for communicating with the Hitachi E7000-PC ICE.
5859 This is available automatically when GDB is configured for the SH.
5863 As usual, a variety of small fixes and improvements, both generic
5864 and configuration-specific. See the ChangeLog for more detail.
5866 *** Changes in GDB-4.12:
5868 * Irix 5 is now supported
5872 GDB-4.12 on the HPPA has a number of changes which make it unable
5873 to debug the output from the currently released versions of GCC and
5874 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5875 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5876 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5879 *** Changes in GDB-4.11:
5881 * User visible changes:
5885 The "set remotedebug" option is now consistent between the mips remote
5886 target, remote targets using the gdb-specific protocol, UDI (AMD's
5887 debug protocol for the 29k) and the 88k bug monitor. It is now an
5888 integer specifying a debug level (normally 0 or 1, but 2 means more
5889 debugging info for the mips target).
5891 * DEC Alpha native support
5893 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5894 debug info, but GDB works fairly well with the DEC compiler and should
5895 work with a future GCC release. See the README file for a few
5896 Alpha-specific notes.
5898 * Preliminary thread implementation
5900 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5902 * LynxOS native and target support for 386
5904 This release has been hosted on LynxOS 2.2, and also can be configured
5905 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5908 * Improvements in C++ mangling/demangling.
5910 This release has much better g++ debugging, specifically in name
5911 mangling/demangling, virtual function calls, print virtual table,
5912 call methods, ...etc.
5914 *** Changes in GDB-4.10:
5916 * User visible changes:
5918 Remote debugging using the GDB-specific (`target remote') protocol now
5919 supports the `load' command. This is only useful if you have some
5920 other way of getting the stub to the target system, and you can put it
5921 somewhere in memory where it won't get clobbered by the download.
5923 Filename completion now works.
5925 When run under emacs mode, the "info line" command now causes the
5926 arrow to point to the line specified. Also, "info line" prints
5927 addresses in symbolic form (as well as hex).
5929 All vxworks based targets now support a user settable option, called
5930 vxworks-timeout. This option represents the number of seconds gdb
5931 should wait for responses to rpc's. You might want to use this if
5932 your vxworks target is, perhaps, a slow software simulator or happens
5933 to be on the far side of a thin network line.
5937 This release contains support for using a DEC alpha as a GDB host for
5938 cross debugging. Native alpha debugging is not supported yet.
5941 *** Changes in GDB-4.9:
5945 This is the first GDB release which is accompanied by a matching testsuite.
5946 The testsuite requires installation of dejagnu, which should be available
5947 via ftp from most sites that carry GNU software.
5951 'Cfront' style demangling has had its name changed to 'ARM' style, to
5952 emphasize that it was written from the specifications in the C++ Annotated
5953 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5954 disclaimers, it still generated too much confusion with users attempting to
5955 use gdb with AT&T cfront.
5959 GDB now uses a standard remote interface to a simulator library.
5960 So far, the library contains simulators for the Zilog Z8001/2, the
5961 Hitachi H8/300, H8/500 and Super-H.
5963 * New targets supported
5965 H8/300 simulator h8300-hitachi-hms or h8300hms
5966 H8/500 simulator h8500-hitachi-hms or h8500hms
5967 SH simulator sh-hitachi-hms or sh
5968 Z8000 simulator z8k-zilog-none or z8ksim
5969 IDT MIPS board over serial line mips-idt-ecoff
5971 Cross-debugging to GO32 targets is supported. It requires a custom
5972 version of the i386-stub.c module which is integrated with the
5973 GO32 memory extender.
5975 * New remote protocols
5977 MIPS remote debugging protocol.
5979 * New source languages supported
5981 This version includes preliminary support for Chill, a Pascal like language
5982 used by telecommunications companies. Chill support is also being integrated
5983 into the GNU compiler, but we don't know when it will be publically available.
5986 *** Changes in GDB-4.8:
5988 * HP Precision Architecture supported
5990 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5991 version of this support was available as a set of patches from the
5992 University of Utah. GDB does not support debugging of programs
5993 compiled with the HP compiler, because HP will not document their file
5994 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5995 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5997 Many problems in the preliminary version have been fixed.
5999 * Faster and better demangling
6001 We have improved template demangling and fixed numerous bugs in the GNU style
6002 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6003 character types (wchar_t) are now supported. Demangling of each symbol is now
6004 only done once, and is cached when the symbol table for a file is read in.
6005 This results in a small increase in memory usage for C programs, a moderate
6006 increase in memory usage for C++ programs, and a fantastic speedup in
6009 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6010 from the specifications in the Annotated Reference Manual, which AT&T's
6011 compiler does not actually implement.
6013 * G++ multiple inheritance compiler problem
6015 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6016 inheritance lattices was reworked to properly discover ambiguities. We
6017 recently found an example which causes this new algorithm to fail in a
6018 very subtle way, producing bad debug information for those classes.
6019 The file 'gcc.patch' (in this directory) can be applied to gcc to
6020 circumvent the problem. A future GCC release will contain a complete
6023 The previous G++ debug info problem (mentioned below for the gdb-4.7
6024 release) is fixed in gcc version 2.3.2.
6026 * Improved configure script
6028 The `configure' script will now attempt to guess your system type if
6029 you don't supply a host system type. The old scheme of supplying a
6030 host system triplet is preferable over using this. All the magic is
6031 done in the new `config.guess' script. Examine it for details.
6033 We have also brought our configure script much more in line with the FSF's
6034 version. It now supports the --with-xxx options. In particular,
6035 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6036 The resulting GDB will not be able to read arbitrary object file formats --
6037 only the format ``expected'' to be used on the configured target system.
6038 We hope to make this the default in a future release.
6040 * Documentation improvements
6042 There's new internal documentation on how to modify GDB, and how to
6043 produce clean changes to the code. We implore people to read it
6044 before submitting changes.
6046 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6047 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6048 `info' files are also provided. To build `info' files from scratch,
6049 you will need the latest `makeinfo' release, which will be available in
6050 a future texinfo-X.Y release.
6052 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6053 We're not sure exactly which versions have this problem, but it has
6054 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6055 or better. If that isn't possible, there is a patch in
6056 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6057 around this problem.
6061 GDB now supports array constants that can be used in expressions typed in by
6062 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6063 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6066 The new directory `gdb/sparclite' contains a program that demonstrates
6067 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6069 * New native hosts supported
6071 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6072 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6074 * New targets supported
6076 AMD 29k family via UDI a29k-amd-udi or udi29k
6078 * New file formats supported
6080 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6081 HPUX core files, and SCO 3.2v2 core files.
6085 Attaching to processes now works again; thanks for the many bug reports.
6087 We have also stomped on a bunch of core dumps caused by
6088 printf_filtered("%s") problems.
6090 We eliminated a copyright problem on the rpc and ptrace header files
6091 for VxWorks, which was discovered at the last minute during the 4.7
6092 release. You should now be able to build a VxWorks GDB.
6094 You can now interrupt gdb while an attached process is running. This
6095 will cause the attached process to stop, and give control back to GDB.
6097 We fixed problems caused by using too many file descriptors
6098 for reading symbols from object files and libraries. This was
6099 especially a problem for programs that used many (~100) shared
6102 The `step' command now only enters a subroutine if there is line number
6103 information for the subroutine. Otherwise it acts like the `next'
6104 command. Previously, `step' would enter subroutines if there was
6105 any debugging information about the routine. This avoids problems
6106 when using `cc -g1' on MIPS machines.
6108 * Internal improvements
6110 GDB's internal interfaces have been improved to make it easier to support
6111 debugging of multiple languages in the future.
6113 GDB now uses a common structure for symbol information internally.
6114 Minimal symbols (derived from linkage symbols in object files), partial
6115 symbols (from a quick scan of debug information), and full symbols
6116 contain a common subset of information, making it easier to write
6117 shared code that handles any of them.
6119 * New command line options
6121 We now accept --silent as an alias for --quiet.
6125 The memory-mapped-malloc library is now licensed under the GNU Library
6126 General Public License.
6128 *** Changes in GDB-4.7:
6130 * Host/native/target split
6132 GDB has had some major internal surgery to untangle the support for
6133 hosts and remote targets. Now, when you configure GDB for a remote
6134 target, it will no longer load in all of the support for debugging
6135 local programs on the host. When fully completed and tested, this will
6136 ensure that arbitrary host/target combinations are possible.
6138 The primary conceptual shift is to separate the non-portable code in
6139 GDB into three categories. Host specific code is required any time GDB
6140 is compiled on that host, regardless of the target. Target specific
6141 code relates to the peculiarities of the target, but can be compiled on
6142 any host. Native specific code is everything else: it can only be
6143 built when the host and target are the same system. Child process
6144 handling and core file support are two common `native' examples.
6146 GDB's use of /proc for controlling Unix child processes is now cleaner.
6147 It has been split out into a single module under the `target_ops' vector,
6148 plus two native-dependent functions for each system that uses /proc.
6150 * New hosts supported
6152 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6153 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6154 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6156 * New targets supported
6158 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6159 68030 and CPU32 m68030-*-*, m68332-*-*
6161 * New native hosts supported
6163 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6164 (386bsd is not well tested yet)
6165 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6167 * New file formats supported
6169 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6170 supports reading of `a.out.adobe' object files, which are an a.out
6171 format extended with minimal information about multiple sections.
6175 `show copying' is the same as the old `info copying'.
6176 `show warranty' is the same as `info warrantee'.
6177 These were renamed for consistency. The old commands continue to work.
6179 `info handle' is a new alias for `info signals'.
6181 You can now define pre-command hooks, which attach arbitrary command
6182 scripts to any command. The commands in the hook will be executed
6183 prior to the user's command. You can also create a hook which will be
6184 executed whenever the program stops. See gdb.texinfo.
6188 We now deal with Cfront style name mangling, and can even extract type
6189 info from mangled symbols. GDB can automatically figure out which
6190 symbol mangling style your C++ compiler uses.
6192 Calling of methods and virtual functions has been improved as well.
6196 The crash that occured when debugging Sun Ansi-C compiled binaries is
6197 fixed. This was due to mishandling of the extra N_SO stabs output
6200 We also finally got Ultrix 4.2 running in house, and fixed core file
6201 support, with help from a dozen people on the net.
6203 John M. Farrell discovered that the reason that single-stepping was so
6204 slow on all of the Mips based platforms (primarily SGI and DEC) was
6205 that we were trying to demangle and lookup a symbol used for internal
6206 purposes on every instruction that was being stepped through. Changing
6207 the name of that symbol so that it couldn't be mistaken for a C++
6208 mangled symbol sped things up a great deal.
6210 Rich Pixley sped up symbol lookups in general by getting much smarter
6211 about when C++ symbol mangling is necessary. This should make symbol
6212 completion (TAB on the command line) much faster. It's not as fast as
6213 we'd like, but it's significantly faster than gdb-4.6.
6217 A new user controllable variable 'call_scratch_address' can
6218 specify the location of a scratch area to be used when GDB
6219 calls a function in the target. This is necessary because the
6220 usual method of putting the scratch area on the stack does not work
6221 in systems that have separate instruction and data spaces.
6223 We integrated changes to support the 29k UDI (Universal Debugger
6224 Interface), but discovered at the last minute that we didn't have all
6225 of the appropriate copyright paperwork. We are working with AMD to
6226 resolve this, and hope to have it available soon.
6230 We have sped up the remote serial line protocol, especially for targets
6231 with lots of registers. It now supports a new `expedited status' ('T')
6232 message which can be used in place of the existing 'S' status message.
6233 This allows the remote stub to send only the registers that GDB
6234 needs to make a quick decision about single-stepping or conditional
6235 breakpoints, eliminating the need to fetch the entire register set for
6236 each instruction being stepped through.
6238 The GDB remote serial protocol now implements a write-through cache for
6239 registers, only re-reading the registers if the target has run.
6241 There is also a new remote serial stub for SPARC processors. You can
6242 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6243 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6244 processor with a serial port.
6248 Configure.in files have become much easier to read and modify. A new
6249 `table driven' format makes it more obvious what configurations are
6250 supported, and what files each one uses.
6254 There is a new opcodes library which will eventually contain all of the
6255 disassembly routines and opcode tables. At present, it only contains
6256 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6257 disassembler (binutils/objdump) to share these routines.
6259 The libiberty library is now copylefted under the GNU Library General
6260 Public License. This allows more liberal use, and was done so libg++
6261 can use it. This makes no difference to GDB, since the Library License
6262 grants all the rights from the General Public License.
6266 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6267 reference to the stabs symbol info used by the debugger. It is (as far
6268 as we know) the only published document on this fascinating topic. We
6269 encourage you to read it, compare it to the stabs information on your
6270 system, and send improvements on the document in general (to
6271 bug-gdb@prep.ai.mit.edu).
6273 And, of course, many bugs have been fixed.
6276 *** Changes in GDB-4.6:
6278 * Better support for C++ function names
6280 GDB now accepts as input the "demangled form" of C++ overloaded function
6281 names and member function names, and can do command completion on such names
6282 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6283 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6284 Make use of command completion, it is your friend.
6286 GDB also now accepts a variety of C++ mangled symbol formats. They are
6287 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6288 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6289 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6290 for the list of formats.
6292 * G++ symbol mangling problem
6294 Recent versions of gcc have a bug in how they emit debugging information for
6295 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6296 directory) can be applied to gcc to fix the problem. Alternatively, if you
6297 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6298 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6299 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6302 * New 'maintenance' command
6304 All of the commands related to hacking GDB internals have been moved out of
6305 the main command set, and now live behind the 'maintenance' command. This
6306 can also be abbreviated as 'mt'. The following changes were made:
6308 dump-me -> maintenance dump-me
6309 info all-breakpoints -> maintenance info breakpoints
6310 printmsyms -> maintenance print msyms
6311 printobjfiles -> maintenance print objfiles
6312 printpsyms -> maintenance print psymbols
6313 printsyms -> maintenance print symbols
6315 The following commands are new:
6317 maintenance demangle Call internal GDB demangler routine to
6318 demangle a C++ link name and prints the result.
6319 maintenance print type Print a type chain for a given symbol
6321 * Change to .gdbinit file processing
6323 We now read the $HOME/.gdbinit file before processing the argv arguments
6324 (e.g. reading symbol files or core files). This allows global parameters to
6325 be set, which will apply during the symbol reading. The ./.gdbinit is still
6326 read after argv processing.
6328 * New hosts supported
6330 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6332 GNU/Linux support i386-unknown-linux or linux
6334 We are also including code to support the HP/PA running BSD and HPUX. This
6335 is almost guaranteed not to work, as we didn't have time to test or build it
6336 for this release. We are including it so that the more adventurous (or
6337 masochistic) of you can play with it. We also had major problems with the
6338 fact that the compiler that we got from HP doesn't support the -g option.
6341 * New targets supported
6343 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6345 * More smarts about finding #include files
6347 GDB now remembers the compilation directory for all include files, and for
6348 all files from which C is generated (like yacc and lex sources). This
6349 greatly improves GDB's ability to find yacc/lex sources, and include files,
6350 especially if you are debugging your program from a directory different from
6351 the one that contains your sources.
6353 We also fixed a bug which caused difficulty with listing and setting
6354 breakpoints in include files which contain C code. (In the past, you had to
6355 try twice in order to list an include file that you hadn't looked at before.)
6357 * Interesting infernals change
6359 GDB now deals with arbitrary numbers of sections, where the symbols for each
6360 section must be relocated relative to that section's landing place in the
6361 target's address space. This work was needed to support ELF with embedded
6362 stabs used by Solaris-2.0.
6364 * Bug fixes (of course!)
6366 There have been loads of fixes for the following things:
6367 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6368 i960, stabs, DOS(GO32), procfs, etc...
6370 See the ChangeLog for details.
6372 *** Changes in GDB-4.5:
6374 * New machines supported (host and target)
6376 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6378 SGI Irix-4.x mips-sgi-irix4 or iris4
6380 * New malloc package
6382 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6383 Mmalloc is capable of handling mutiple heaps of memory. It is also
6384 capable of saving a heap to a file, and then mapping it back in later.
6385 This can be used to greatly speedup the startup of GDB by using a
6386 pre-parsed symbol table which lives in a mmalloc managed heap. For
6387 more details, please read mmalloc/mmalloc.texi.
6391 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6392 'help info proc' for details.
6394 * MIPS ecoff symbol table format
6396 The code that reads MIPS symbol table format is now supported on all hosts.
6397 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6400 * File name changes for MS-DOS
6402 Many files in the config directories have been renamed to make it easier to
6403 support GDB on MS-DOSe systems (which have very restrictive file name
6404 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6405 environment) is close to working but has some remaining problems. Note
6406 that debugging of DOS programs is not supported, due to limitations
6407 in the ``operating system'', but it can be used to host cross-debugging.
6409 * Cross byte order fixes
6411 Many fixes have been made to support cross debugging of Sparc and MIPS
6412 targets from hosts whose byte order differs.
6414 * New -mapped and -readnow options
6416 If memory-mapped files are available on your system through the 'mmap'
6417 system call, you can use the -mapped option on the `file' or
6418 `symbol-file' commands to cause GDB to write the symbols from your
6419 program into a reusable file. If the program you are debugging is
6420 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6421 Future GDB debugging sessions will notice the presence of this file,
6422 and will quickly map in symbol information from it, rather than reading
6423 the symbol table from the executable program. Using the '-mapped'
6424 option in a GDB `file' or `symbol-file' command has the same effect as
6425 starting GDB with the '-mapped' command-line option.
6427 You can cause GDB to read the entire symbol table immediately by using
6428 the '-readnow' option with any of the commands that load symbol table
6429 information (or on the GDB command line). This makes the command
6430 slower, but makes future operations faster.
6432 The -mapped and -readnow options are typically combined in order to
6433 build a `fred.syms' file that contains complete symbol information.
6434 A simple GDB invocation to do nothing but build a `.syms' file for future
6437 gdb -batch -nx -mapped -readnow programname
6439 The `.syms' file is specific to the host machine on which GDB is run.
6440 It holds an exact image of GDB's internal symbol table. It cannot be
6441 shared across multiple host platforms.
6443 * longjmp() handling
6445 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6446 siglongjmp() without losing control. This feature has not yet been ported to
6447 all systems. It currently works on many 386 platforms, all MIPS-based
6448 platforms (SGI, DECstation, etc), and Sun3/4.
6452 Preliminary work has been put in to support the new Solaris OS from Sun. At
6453 this time, it can control and debug processes, but it is not capable of
6458 As always, many many bug fixes. The major areas were with g++, and mipsread.
6459 People using the MIPS-based platforms should experience fewer mysterious
6460 crashes and trashed symbol tables.
6462 *** Changes in GDB-4.4:
6464 * New machines supported (host and target)
6466 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6468 BSD Reno on Vax vax-dec-bsd
6469 Ultrix on Vax vax-dec-ultrix
6471 * New machines supported (target)
6473 AMD 29000 embedded, using EBMON a29k-none-none
6477 GDB continues to improve its handling of C++. `References' work better.
6478 The demangler has also been improved, and now deals with symbols mangled as
6479 per the Annotated C++ Reference Guide.
6481 GDB also now handles `stabs' symbol information embedded in MIPS
6482 `ecoff' symbol tables. Since the ecoff format was not easily
6483 extensible to handle new languages such as C++, this appeared to be a
6484 good way to put C++ debugging info into MIPS binaries. This option
6485 will be supported in the GNU C compiler, version 2, when it is
6488 * New features for SVR4
6490 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6491 shared libraries. Debugging dynamically linked programs should present
6492 only minor differences from debugging statically linked programs.
6494 The `info proc' command will print out information about any process
6495 on an SVR4 system (including the one you are debugging). At the moment,
6496 it prints the address mappings of the process.
6498 If you bring up GDB on another SVR4 system, please send mail to
6499 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6501 * Better dynamic linking support in SunOS
6503 Reading symbols from shared libraries which contain debugging symbols
6504 now works properly. However, there remain issues such as automatic
6505 skipping of `transfer vector' code during function calls, which
6506 make it harder to debug code in a shared library, than to debug the
6507 same code linked statically.
6511 GDB is now using the latest `getopt' routines from the FSF. This
6512 version accepts the -- prefix for options with long names. GDB will
6513 continue to accept the old forms (-option and +option) as well.
6514 Various single letter abbreviations for options have been explicity
6515 added to the option table so that they won't get overshadowed in the
6516 future by other options that begin with the same letter.
6520 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6521 Many assorted bugs have been handled. Many more remain to be handled.
6522 See the various ChangeLog files (primarily in gdb and bfd) for details.
6525 *** Changes in GDB-4.3:
6527 * New machines supported (host and target)
6529 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6530 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6531 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6533 * Almost SCO Unix support
6535 We had hoped to support:
6536 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6537 (except for core file support), but we discovered very late in the release
6538 that it has problems with process groups that render gdb unusable. Sorry
6539 about that. I encourage people to fix it and post the fixes.
6541 * Preliminary ELF and DWARF support
6543 GDB can read ELF object files on System V Release 4, and can handle
6544 debugging records for C, in DWARF format, in ELF files. This support
6545 is preliminary. If you bring up GDB on another SVR4 system, please
6546 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6551 GDB now uses the latest `readline' library. One user-visible change
6552 is that two tabs will list possible command completions, which previously
6553 required typing M-? (meta-question mark, or ESC ?).
6557 The `stepi' bug that many of you noticed has been squashed.
6558 Many bugs in C++ have been handled. Many more remain to be handled.
6559 See the various ChangeLog files (primarily in gdb and bfd) for details.
6561 * State of the MIPS world (in case you wondered):
6563 GDB can understand the symbol tables emitted by the compilers
6564 supplied by most vendors of MIPS-based machines, including DEC. These
6565 symbol tables are in a format that essentially nobody else uses.
6567 Some versions of gcc come with an assembler post-processor called
6568 mips-tfile. This program is required if you want to do source-level
6569 debugging of gcc-compiled programs. I believe FSF does not ship
6570 mips-tfile with gcc version 1, but it will eventually come with gcc
6573 Debugging of g++ output remains a problem. g++ version 1.xx does not
6574 really support it at all. (If you're lucky, you should be able to get
6575 line numbers and stack traces to work, but no parameters or local
6576 variables.) With some work it should be possible to improve the
6579 When gcc version 2 is released, you will have somewhat better luck.
6580 However, even then you will get confusing results for inheritance and
6583 We will eventually provide full debugging of g++ output on
6584 DECstations. This will probably involve some kind of stabs-in-ecoff
6585 encapulation, but the details have not been worked out yet.
6588 *** Changes in GDB-4.2:
6590 * Improved configuration
6592 Only one copy of `configure' exists now, and it is not self-modifying.
6593 Porting BFD is simpler.
6597 The `step' and `next' commands now only stop at the first instruction
6598 of a source line. This prevents the multiple stops that used to occur
6599 in switch statements, for-loops, etc. `Step' continues to stop if a
6600 function that has debugging information is called within the line.
6604 Lots of small bugs fixed. More remain.
6606 * New host supported (not target)
6608 Intel 386 PC clone running Mach i386-none-mach
6611 *** Changes in GDB-4.1:
6613 * Multiple source language support
6615 GDB now has internal scaffolding to handle several source languages.
6616 It determines the type of each source file from its filename extension,
6617 and will switch expression parsing and number formatting to match the
6618 language of the function in the currently selected stack frame.
6619 You can also specifically set the language to be used, with
6620 `set language c' or `set language modula-2'.
6624 GDB now has preliminary support for the GNU Modula-2 compiler,
6625 currently under development at the State University of New York at
6626 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6627 continue through the fall of 1991 and into 1992.
6629 Other Modula-2 compilers are currently not supported, and attempting to
6630 debug programs compiled with them will likely result in an error as the
6631 symbol table is read. Feel free to work on it, though!
6633 There are hooks in GDB for strict type checking and range checking,
6634 in the `Modula-2 philosophy', but they do not currently work.
6638 GDB can now write to executable and core files (e.g. patch
6639 a variable's value). You must turn this switch on, specify
6640 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6641 by assigning a new value to a variable. Modifications take
6644 * Automatic SunOS shared library reading
6646 When you run your program, GDB automatically determines where its
6647 shared libraries (if any) have been loaded, and reads their symbols.
6648 The `share' command is no longer needed. This also works when
6649 examining core files.
6653 You can specify the number of lines that the `list' command shows.
6656 * New machines supported (host and target)
6658 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6659 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6660 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6662 * New hosts supported (not targets)
6664 IBM RT/PC: romp-ibm-aix or rtpc
6666 * New targets supported (not hosts)
6668 AMD 29000 embedded with COFF a29k-none-coff
6669 AMD 29000 embedded with a.out a29k-none-aout
6670 Ultracomputer remote kernel debug a29k-nyu-kern
6672 * New remote interfaces
6678 *** Changes in GDB-4.0:
6682 Wide output is wrapped at good places to make the output more readable.
6684 Gdb now supports cross-debugging from a host machine of one type to a
6685 target machine of another type. Communication with the target system
6686 is over serial lines. The ``target'' command handles connecting to the
6687 remote system; the ``load'' command will download a program into the
6688 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6689 also supports debugging of realtime processes running under VxWorks,
6690 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6691 stub on the target system.
6693 New CPUs supported include the AMD 29000 and Intel 960.
6695 GDB now reads object files and symbol tables via a ``binary file''
6696 library, which allows a single copy of GDB to debug programs of multiple
6697 object file types such as a.out and coff.
6699 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6700 refcard.dvi and refcard.ps are available to format it).
6703 * Control-Variable user interface simplified
6705 All variables that control the operation of the debugger can be set
6706 by the ``set'' command, and displayed by the ``show'' command.
6708 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6709 ``Show prompt'' produces the response:
6710 Gdb's prompt is new-gdb=>.
6712 What follows are the NEW set commands. The command ``help set'' will
6713 print a complete list of old and new set commands. ``help set FOO''
6714 will give a longer description of the variable FOO. ``show'' will show
6715 all of the variable descriptions and their current settings.
6717 confirm on/off: Enables warning questions for operations that are
6718 hard to recover from, e.g. rerunning the program while
6719 it is already running. Default is ON.
6721 editing on/off: Enables EMACS style command line editing
6722 of input. Previous lines can be recalled with
6723 control-P, the current line can be edited with control-B,
6724 you can search for commands with control-R, etc.
6727 history filename NAME: NAME is where the gdb command history
6728 will be stored. The default is .gdb_history,
6729 or the value of the environment variable
6732 history size N: The size, in commands, of the command history. The
6733 default is 256, or the value of the environment variable
6736 history save on/off: If this value is set to ON, the history file will
6737 be saved after exiting gdb. If set to OFF, the
6738 file will not be saved. The default is OFF.
6740 history expansion on/off: If this value is set to ON, then csh-like
6741 history expansion will be performed on
6742 command line input. The default is OFF.
6744 radix N: Sets the default radix for input and output. It can be set
6745 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6746 in the current radix, so "set radix 10" is always a no-op.
6748 height N: This integer value is the number of lines on a page. Default
6749 is 24, the current `stty rows'' setting, or the ``li#''
6750 setting from the termcap entry matching the environment
6753 width N: This integer value is the number of characters on a line.
6754 Default is 80, the current `stty cols'' setting, or the ``co#''
6755 setting from the termcap entry matching the environment
6758 Note: ``set screensize'' is obsolete. Use ``set height'' and
6759 ``set width'' instead.
6761 print address on/off: Print memory addresses in various command displays,
6762 such as stack traces and structure values. Gdb looks
6763 more ``symbolic'' if you turn this off; it looks more
6764 ``machine level'' with it on. Default is ON.
6766 print array on/off: Prettyprint arrays. New convenient format! Default
6769 print demangle on/off: Print C++ symbols in "source" form if on,
6772 print asm-demangle on/off: Same, for assembler level printouts
6775 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6778 * Support for Epoch Environment.
6780 The epoch environment is a version of Emacs v18 with windowing. One
6781 new command, ``inspect'', is identical to ``print'', except that if you
6782 are running in the epoch environment, the value is printed in its own
6786 * Support for Shared Libraries
6788 GDB can now debug programs and core files that use SunOS shared libraries.
6789 Symbols from a shared library cannot be referenced
6790 before the shared library has been linked with the program (this
6791 happens after you type ``run'' and before the function main() is entered).
6792 At any time after this linking (including when examining core files
6793 from dynamically linked programs), gdb reads the symbols from each
6794 shared library when you type the ``sharedlibrary'' command.
6795 It can be abbreviated ``share''.
6797 sharedlibrary REGEXP: Load shared object library symbols for files
6798 matching a unix regular expression. No argument
6799 indicates to load symbols for all shared libraries.
6801 info sharedlibrary: Status of loaded shared libraries.
6806 A watchpoint stops execution of a program whenever the value of an
6807 expression changes. Checking for this slows down execution
6808 tremendously whenever you are in the scope of the expression, but is
6809 quite useful for catching tough ``bit-spreader'' or pointer misuse
6810 problems. Some machines such as the 386 have hardware for doing this
6811 more quickly, and future versions of gdb will use this hardware.
6813 watch EXP: Set a watchpoint (breakpoint) for an expression.
6815 info watchpoints: Information about your watchpoints.
6817 delete N: Deletes watchpoint number N (same as breakpoints).
6818 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6819 enable N: Re-enables watchpoint number N (same as breakpoints).
6822 * C++ multiple inheritance
6824 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6827 * C++ exception handling
6829 Gdb now supports limited C++ exception handling. Besides the existing
6830 ability to breakpoint on an exception handler, gdb can breakpoint on
6831 the raising of an exception (before the stack is peeled back to the
6834 catch FOO: If there is a FOO exception handler in the dynamic scope,
6835 set a breakpoint to catch exceptions which may be raised there.
6836 Multiple exceptions (``catch foo bar baz'') may be caught.
6838 info catch: Lists all exceptions which may be caught in the
6839 current stack frame.
6842 * Minor command changes
6844 The command ``call func (arg, arg, ...)'' now acts like the print
6845 command, except it does not print or save a value if the function's result
6846 is void. This is similar to dbx usage.
6848 The ``up'' and ``down'' commands now always print the frame they end up
6849 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6850 frames without printing.
6852 * New directory command
6854 'dir' now adds directories to the FRONT of the source search path.
6855 The path starts off empty. Source files that contain debug information
6856 about the directory in which they were compiled can be found even
6857 with an empty path; Sun CC and GCC include this information. If GDB can't
6858 find your source file in the current directory, type "dir .".
6860 * Configuring GDB for compilation
6862 For normal use, type ``./configure host''. See README or gdb.texinfo
6865 GDB now handles cross debugging. If you are remotely debugging between
6866 two different machines, type ``./configure host -target=targ''.
6867 Host is the machine where GDB will run; targ is the machine
6868 where the program that you are debugging will run.
projects / binutils-gdb.git / blob