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.
91 QEnvironmentHexEncoded
92 Inform GDBserver of an environment variable that is to be passed to
93 the inferior when starting it.
96 Inform GDBserver of an environment variable that is to be unset
97 before starting the remote inferior.
100 Inform GDBserver that the environment should be reset (i.e.,
101 user-set environment variables should be unset).
104 Indicates whether the inferior must be started with a shell or not.
107 Tell GDBserver that the inferior to be started should use a specific
110 * The "maintenance print c-tdesc" command now takes an optional
111 argument which is the file name of XML target description.
113 * The "maintenance selftest" command now takes an optional argument to
114 filter the tests to be run.
116 * The "enable", and "disable" commands now accept a range of
117 breakpoint locations, e.g. "enable 1.3-5".
122 Set and show the current working directory for the inferior.
125 Set and show compilation command used for compiling and injecting code
126 with the 'compile' commands.
128 set debug separate-debug-file
129 show debug separate-debug-file
130 Control the display of debug output about separate debug file search.
133 List the registered selftests.
136 Start the debugged program stopping at the first instruction.
138 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
141 * Safer/improved support for debugging with no debug info
143 GDB no longer assumes functions with no debug information return
146 This means that GDB now refuses to call such functions unless you
147 tell it the function's type, by either casting the call to the
148 declared return type, or by casting the function to a function
149 pointer of the right type, and calling that:
151 (gdb) p getenv ("PATH")
152 'getenv' has unknown return type; cast the call to its declared return type
153 (gdb) p (char *) getenv ("PATH")
154 $1 = 0x7fffffffe "/usr/local/bin:/"...
155 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
156 $2 = 0x7fffffffe "/usr/local/bin:/"...
158 Similarly, GDB no longer assumes that global variables with no debug
159 info have type 'int', and refuses to print the variable's value
160 unless you tell it the variable's type:
163 'var' has unknown type; cast it to its declared type
167 * New native configurations
169 FreeBSD/aarch64 aarch64*-*-freebsd*
170 FreeBSD/arm arm*-*-freebsd*
174 FreeBSD/aarch64 aarch64*-*-freebsd*
175 FreeBSD/arm arm*-*-freebsd*
177 * Removed targets and native configurations
179 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
181 *** Changes in GDB 8.0
183 * GDB now supports access to the PKU register on GNU/Linux. The register is
184 added by the Memory Protection Keys for Userspace feature which will be
185 available in future Intel CPUs.
187 * GDB now supports C++11 rvalue references.
191 ** New functions to start, stop and access a running btrace recording.
192 ** Rvalue references are now supported in gdb.Type.
194 * GDB now supports recording and replaying rdrand and rdseed Intel 64
197 * Building GDB and GDBserver now requires a C++11 compiler.
199 For example, GCC 4.8 or later.
201 It is no longer possible to build GDB or GDBserver with a C
202 compiler. The --disable-build-with-cxx configure option has been
205 * Building GDB and GDBserver now requires GNU make >= 3.81.
207 It is no longer supported to build GDB or GDBserver with another
208 implementation of the make program or an earlier version of GNU make.
210 * Native debugging on MS-Windows supports command-line redirection
212 Command-line arguments used for starting programs on MS-Windows can
213 now include redirection symbols supported by native Windows shells,
214 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
215 as "run", "start", and "set args", as well as the corresponding MI
218 * Support for thread names on MS-Windows.
220 GDB now catches and handles the special exception that programs
221 running on MS-Windows use to assign names to threads in the
224 * Support for Java programs compiled with gcj has been removed.
226 * User commands now accept an unlimited number of arguments.
227 Previously, only up to 10 was accepted.
229 * The "eval" command now expands user-defined command arguments.
231 This makes it easier to process a variable number of arguments:
236 eval "print $arg%d", $i
241 * Target descriptions can now describe registers for sparc32 and sparc64.
243 * GDB now supports DWARF version 5 (debug information format).
244 Its .debug_names index is not yet supported.
246 * New native configurations
248 FreeBSD/mips mips*-*-freebsd
252 Synopsys ARC arc*-*-elf32
253 FreeBSD/mips mips*-*-freebsd
255 * Removed targets and native configurations
257 Alpha running FreeBSD alpha*-*-freebsd*
258 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
263 Erases all the flash memory regions reported by the target.
265 maint print arc arc-instruction address
266 Print internal disassembler information about instruction at a given address.
270 set disassembler-options
271 show disassembler-options
272 Controls the passing of target specific information to the disassembler.
273 If it is necessary to specify more than one disassembler option then
274 multiple options can be placed together into a comma separated list.
275 The default value is the empty string. Currently, the only supported
276 targets are ARM, PowerPC and S/390.
281 Erases all the flash memory regions reported by the target. This is
282 equivalent to the CLI command flash-erase.
284 -file-list-shared-libraries
285 List the shared libraries in the program. This is
286 equivalent to the CLI command "info shared".
288 *** Changes in GDB 7.12
290 * GDB and GDBserver now build with a C++ compiler by default.
292 The --enable-build-with-cxx configure option is now enabled by
293 default. One must now explicitly configure with
294 --disable-build-with-cxx in order to build with a C compiler. This
295 option will be removed in a future release.
297 * GDBserver now supports recording btrace without maintaining an active
300 * GDB now supports a negative repeat count in the 'x' command to examine
301 memory backward from the given address. For example:
304 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
305 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
306 (gdb) x/-5i 0x0000000000400580
307 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
308 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
309 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
310 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
311 0x40057b <main(int, char**)+25>:
312 callq 0x400536 <Func1(int, char const*)>
314 * Fortran: Support structures with fields of dynamic types and
315 arrays of dynamic types.
317 * The symbol dumping maintenance commands have new syntax.
318 maint print symbols [-pc address] [--] [filename]
319 maint print symbols [-objfile objfile] [-source source] [--] [filename]
320 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
321 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
322 maint print msymbols [-objfile objfile] [--] [filename]
324 * GDB now supports multibit bitfields and enums in target register
327 * New Python-based convenience function $_as_string(val), which returns
328 the textual representation of a value. This function is especially
329 useful to obtain the text label of an enum value.
331 * Intel MPX bound violation handling.
333 Segmentation faults caused by a Intel MPX boundary violation
334 now display the kind of violation (upper or lower), the memory
335 address accessed and the memory bounds, along with the usual
336 signal received and code location.
340 Program received signal SIGSEGV, Segmentation fault
341 Upper bound violation while accessing address 0x7fffffffc3b3
342 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
343 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
345 * Rust language support.
346 GDB now supports debugging programs written in the Rust programming
347 language. See https://www.rust-lang.org/ for more information about
350 * Support for running interpreters on specified input/output devices
352 GDB now supports a new mechanism that allows frontends to provide
353 fully featured GDB console views, as a better alternative to
354 building such views on top of the "-interpreter-exec console"
355 command. See the new "new-ui" command below. With that command,
356 frontends can now start GDB in the traditional command-line mode
357 running in an embedded terminal emulator widget, and create a
358 separate MI interpreter running on a specified i/o device. In this
359 way, GDB handles line editing, history, tab completion, etc. in the
360 console all by itself, and the GUI uses the separate MI interpreter
361 for its own control and synchronization, invisible to the command
364 * The "catch syscall" command catches groups of related syscalls.
366 The "catch syscall" command now supports catching a group of related
367 syscalls using the 'group:' or 'g:' prefix.
372 skip -gfile file-glob-pattern
373 skip -function function
374 skip -rfunction regular-expression
375 A generalized form of the skip command, with new support for
376 glob-style file names and regular expressions for function names.
377 Additionally, a file spec and a function spec may now be combined.
379 maint info line-table REGEXP
380 Display the contents of GDB's internal line table data struture.
383 Run any GDB unit tests that were compiled in.
386 Start a new user interface instance running INTERP as interpreter,
387 using the TTY file for input/output.
391 ** gdb.Breakpoint objects have a new attribute "pending", which
392 indicates whether the breakpoint is pending.
393 ** Three new breakpoint-related events have been added:
394 gdb.breakpoint_created, gdb.breakpoint_modified, and
395 gdb.breakpoint_deleted.
398 Signal ("set") the given MS-Windows event object. This is used in
399 conjunction with the Windows JIT debugging (AeDebug) support, where
400 the OS suspends a crashing process until a debugger can attach to
401 it. Resuming the crashing process, in order to debug it, is done by
404 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
405 was added in GDBserver, including JIT compiling fast tracepoint's
406 conditional expression bytecode into native code.
408 * Support for various remote target protocols and ROM monitors has
411 target m32rsdi Remote M32R debugging over SDI
412 target mips MIPS remote debugging protocol
413 target pmon PMON ROM monitor
414 target ddb NEC's DDB variant of PMON for Vr4300
415 target rockhopper NEC RockHopper variant of PMON
416 target lsi LSI variant of PMO
418 * Support for tracepoints and fast tracepoints on powerpc-linux,
419 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
420 including JIT compiling fast tracepoint's conditional expression
421 bytecode into native code.
423 * MI async record =record-started now includes the method and format used for
424 recording. For example:
426 =record-started,thread-group="i1",method="btrace",format="bts"
428 * MI async record =thread-selected now includes the frame field. For example:
430 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
434 Andes NDS32 nds32*-*-elf
436 *** Changes in GDB 7.11
438 * GDB now supports debugging kernel-based threads on FreeBSD.
440 * Per-inferior thread numbers
442 Thread numbers are now per inferior instead of global. If you're
443 debugging multiple inferiors, GDB displays thread IDs using a
444 qualified INF_NUM.THR_NUM form. For example:
448 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
449 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
450 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
451 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
453 As consequence, thread numbers as visible in the $_thread
454 convenience variable and in Python's InferiorThread.num attribute
455 are no longer unique between inferiors.
457 GDB now maintains a second thread ID per thread, referred to as the
458 global thread ID, which is the new equivalent of thread numbers in
459 previous releases. See also $_gthread below.
461 For backwards compatibility, MI's thread IDs always refer to global
464 * Commands that accept thread IDs now accept the qualified
465 INF_NUM.THR_NUM form as well. For example:
468 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
471 * In commands that accept a list of thread IDs, you can now refer to
472 all threads of an inferior using a star wildcard. GDB accepts
473 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
474 refer to all threads of the current inferior. For example, "info
477 * You can use "info threads -gid" to display the global thread ID of
480 * The new convenience variable $_gthread holds the global number of
483 * The new convenience variable $_inferior holds the number of the
486 * GDB now displays the ID and name of the thread that hit a breakpoint
487 or received a signal, if your program is multi-threaded. For
490 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
491 Thread 1 "main" received signal SIGINT, Interrupt.
493 * Record btrace now supports non-stop mode.
495 * Support for tracepoints on aarch64-linux was added in GDBserver.
497 * The 'record instruction-history' command now indicates speculative execution
498 when using the Intel Processor Trace recording format.
500 * GDB now allows users to specify explicit locations, bypassing
501 the linespec parser. This feature is also available to GDB/MI
504 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
505 GDB now is able to debug both AArch64 applications and ARM applications
508 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
509 including JIT compiling fast tracepoint's conditional expression bytecode
512 * GDB now supports displaced stepping on AArch64 GNU/Linux.
514 * "info threads", "info inferiors", "info display", "info checkpoints"
515 and "maint info program-spaces" now list the corresponding items in
516 ascending ID order, for consistency with all other "info" commands.
518 * In Ada, the overloads selection menu has been enhanced to display the
519 parameter types and the return types for the matching overloaded subprograms.
523 maint set target-non-stop (on|off|auto)
524 maint show target-non-stop
525 Control whether GDB targets always operate in non-stop mode even if
526 "set non-stop" is "off". The default is "auto", meaning non-stop
527 mode is enabled if supported by the target.
529 maint set bfd-sharing
530 maint show bfd-sharing
531 Control the reuse of bfd objects.
535 Control display of debugging info regarding bfd caching.
539 Control display of debugging info regarding FreeBSD threads.
541 set remote multiprocess-extensions-packet
542 show remote multiprocess-extensions-packet
543 Set/show the use of the remote protocol multiprocess extensions.
545 set remote thread-events
546 show remote thread-events
547 Set/show the use of thread create/exit events.
549 set ada print-signatures on|off
550 show ada print-signatures"
551 Control whether parameter types and return types are displayed in overloads
552 selection menus. It is activaled (@code{on}) by default.
556 Controls the maximum size of memory, in bytes, that GDB will
557 allocate for value contents. Prevents incorrect programs from
558 causing GDB to allocate overly large buffers. Default is 64k.
560 * The "disassemble" command accepts a new modifier: /s.
561 It prints mixed source+disassembly like /m with two differences:
562 - disassembled instructions are now printed in program order, and
563 - and source for all relevant files is now printed.
564 The "/m" option is now considered deprecated: its "source-centric"
565 output hasn't proved useful in practice.
567 * The "record instruction-history" command accepts a new modifier: /s.
568 It behaves exactly like /m and prints mixed source+disassembly.
570 * The "set scheduler-locking" command supports a new mode "replay".
571 It behaves like "off" in record mode and like "on" in replay mode.
573 * Support for various ROM monitors has been removed:
575 target dbug dBUG ROM monitor for Motorola ColdFire
576 target picobug Motorola picobug monitor
577 target dink32 DINK32 ROM monitor for PowerPC
578 target m32r Renesas M32R/D ROM monitor
579 target mon2000 mon2000 ROM monitor
580 target ppcbug PPCBUG ROM monitor for PowerPC
582 * Support for reading/writing memory and extracting values on architectures
583 whose memory is addressable in units of any integral multiple of 8 bits.
588 Indicates that an exec system call was executed.
590 exec-events feature in qSupported
591 The qSupported packet allows GDB to request support for exec
592 events using the new 'gdbfeature' exec-event, and the qSupported
593 response can contain the corresponding 'stubfeature'. Set and
594 show commands can be used to display whether these features are enabled.
597 Equivalent to interrupting with the ^C character, but works in
600 thread created stop reason (T05 create:...)
601 Indicates that the thread was just created and is stopped at entry.
603 thread exit stop reply (w exitcode;tid)
604 Indicates that the thread has terminated.
607 Enables/disables thread create and exit event reporting. For
608 example, this is used in non-stop mode when GDB stops a set of
609 threads and synchronously waits for the their corresponding stop
610 replies. Without exit events, if one of the threads exits, GDB
611 would hang forever not knowing that it should no longer expect a
612 stop for that same thread.
615 Indicates that there are no resumed threads left in the target (all
616 threads are stopped). The remote stub reports support for this stop
617 reply to GDB's qSupported query.
620 Enables/disables catching syscalls from the inferior process.
621 The remote stub reports support for this packet to GDB's qSupported query.
623 syscall_entry stop reason
624 Indicates that a syscall was just called.
626 syscall_return stop reason
627 Indicates that a syscall just returned.
629 * Extended-remote exec events
631 ** GDB now has support for exec events on extended-remote Linux targets.
632 For such targets with Linux kernels 2.5.46 and later, this enables
633 follow-exec-mode and exec catchpoints.
635 set remote exec-event-feature-packet
636 show remote exec-event-feature-packet
637 Set/show the use of the remote exec event feature.
639 * Thread names in remote protocol
641 The reply to qXfer:threads:read may now include a name attribute for each
644 * Target remote mode fork and exec events
646 ** GDB now has support for fork and exec events on target remote mode
647 Linux targets. For such targets with Linux kernels 2.5.46 and later,
648 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
649 fork and exec catchpoints.
651 * Remote syscall events
653 ** GDB now has support for catch syscall on remote Linux targets,
654 currently enabled on x86/x86_64 architectures.
656 set remote catch-syscall-packet
657 show remote catch-syscall-packet
658 Set/show the use of the remote catch syscall feature.
662 ** The -var-set-format command now accepts the zero-hexadecimal
663 format. It outputs data in hexadecimal format with zero-padding on the
668 ** gdb.InferiorThread objects have a new attribute "global_num",
669 which refers to the thread's global thread ID. The existing
670 "num" attribute now refers to the thread's per-inferior number.
671 See "Per-inferior thread numbers" above.
672 ** gdb.InferiorThread objects have a new attribute "inferior", which
673 is the Inferior object the thread belongs to.
675 *** Changes in GDB 7.10
677 * Support for process record-replay and reverse debugging on aarch64*-linux*
678 targets has been added. GDB now supports recording of A64 instruction set
679 including advance SIMD instructions.
681 * Support for Sun's version of the "stabs" debug file format has been removed.
683 * GDB now honors the content of the file /proc/PID/coredump_filter
684 (PID is the process ID) on GNU/Linux systems. This file can be used
685 to specify the types of memory mappings that will be included in a
686 corefile. For more information, please refer to the manual page of
687 "core(5)". GDB also has a new command: "set use-coredump-filter
688 on|off". It allows to set whether GDB will read the content of the
689 /proc/PID/coredump_filter file when generating a corefile.
691 * The "info os" command on GNU/Linux can now display information on
693 "info os cpus" Listing of all cpus/cores on the system
695 * GDB has two new commands: "set serial parity odd|even|none" and
696 "show serial parity". These allows to set or show parity for the
699 * The "info source" command now displays the producer string if it was
700 present in the debug info. This typically includes the compiler version
701 and may include things like its command line arguments.
703 * The "info dll", an alias of the "info sharedlibrary" command,
704 is now available on all platforms.
706 * Directory names supplied to the "set sysroot" commands may be
707 prefixed with "target:" to tell GDB to access shared libraries from
708 the target system, be it local or remote. This replaces the prefix
709 "remote:". The default sysroot has been changed from "" to
710 "target:". "remote:" is automatically converted to "target:" for
711 backward compatibility.
713 * The system root specified by "set sysroot" will be prepended to the
714 filename of the main executable (if reported to GDB as absolute by
715 the operating system) when starting processes remotely, and when
716 attaching to already-running local or remote processes.
718 * GDB now supports automatic location and retrieval of executable
719 files from remote targets. Remote debugging can now be initiated
720 using only a "target remote" or "target extended-remote" command
721 (no "set sysroot" or "file" commands are required). See "New remote
724 * The "dump" command now supports verilog hex format.
726 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
728 * On GNU/Linux, GDB and gdbserver are now able to access executable
729 and shared library files without a "set sysroot" command when
730 attaching to processes running in different mount namespaces from
731 the debugger. This makes it possible to attach to processes in
732 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
733 See "New remote packets" below.
735 * The "tui reg" command now provides completion for all of the
736 available register groups, including target specific groups.
738 * The HISTSIZE environment variable is no longer read when determining
739 the size of GDB's command history. GDB now instead reads the dedicated
740 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
741 disables truncation of command history. Non-numeric values of GDBHISTSIZE
746 ** Memory ports can now be unbuffered.
750 ** gdb.Objfile objects have a new attribute "username",
751 which is the name of the objfile as specified by the user,
752 without, for example, resolving symlinks.
753 ** You can now write frame unwinders in Python.
754 ** gdb.Type objects have a new method "optimized_out",
755 returning optimized out gdb.Value instance of this type.
756 ** gdb.Value objects have new methods "reference_value" and
757 "const_value" which return a reference to the value and a
758 "const" version of the value respectively.
762 maint print symbol-cache
763 Print the contents of the symbol cache.
765 maint print symbol-cache-statistics
766 Print statistics of symbol cache usage.
768 maint flush-symbol-cache
769 Flush the contents of the symbol cache.
773 Start branch trace recording using Branch Trace Store (BTS) format.
776 Evaluate expression by using the compiler and print result.
780 Explicit commands for enabling and disabling tui mode.
783 set mpx bound on i386 and amd64
784 Support for bound table investigation on Intel MPX enabled applications.
788 Start branch trace recording using Intel Processor Trace format.
791 Print information about branch tracing internals.
793 maint btrace packet-history
794 Print the raw branch tracing data.
796 maint btrace clear-packet-history
797 Discard the stored raw branch tracing data.
800 Discard all branch tracing data. It will be fetched and processed
801 anew by the next "record" command.
806 Renamed from "set debug dwarf2-die".
808 Renamed from "show debug dwarf2-die".
811 Renamed from "set debug dwarf2-read".
812 show debug dwarf-read
813 Renamed from "show debug dwarf2-read".
815 maint set dwarf always-disassemble
816 Renamed from "maint set dwarf2 always-disassemble".
817 maint show dwarf always-disassemble
818 Renamed from "maint show dwarf2 always-disassemble".
820 maint set dwarf max-cache-age
821 Renamed from "maint set dwarf2 max-cache-age".
822 maint show dwarf max-cache-age
823 Renamed from "maint show dwarf2 max-cache-age".
826 show debug dwarf-line
827 Control display of debugging info regarding DWARF line processing.
831 Set the maximum number of candidates to be considered during
832 completion. The default value is 200. This limit allows GDB
833 to avoid generating large completion lists, the computation of
834 which can cause the debugger to become temporarily unresponsive.
836 set history remove-duplicates
837 show history remove-duplicates
838 Control the removal of duplicate history entries.
840 maint set symbol-cache-size
841 maint show symbol-cache-size
842 Control the size of the symbol cache.
844 set|show record btrace bts buffer-size
845 Set and show the size of the ring buffer used for branch tracing in
847 The obtained size may differ from the requested size. Use "info
848 record" to see the obtained buffer size.
850 set debug linux-namespaces
851 show debug linux-namespaces
852 Control display of debugging info regarding Linux namespaces.
854 set|show record btrace pt buffer-size
855 Set and show the size of the ring buffer used for branch tracing in
856 Intel Processor Trace format.
857 The obtained size may differ from the requested size. Use "info
858 record" to see the obtained buffer size.
860 maint set|show btrace pt skip-pad
861 Set and show whether PAD packets are skipped when computing the
864 * The command 'thread apply all' can now support new option '-ascending'
865 to call its specified command for all threads in ascending order.
867 * Python/Guile scripting
869 ** GDB now supports auto-loading of Python/Guile scripts contained in the
870 special section named `.debug_gdb_scripts'.
874 qXfer:btrace-conf:read
875 Return the branch trace configuration for the current thread.
877 Qbtrace-conf:bts:size
878 Set the requested ring buffer size for branch tracing in BTS format.
881 Enable Intel Procesor Trace-based branch tracing for the current
882 process. The remote stub reports support for this packet to GDB's
886 Set the requested ring buffer size for branch tracing in Intel Processor
890 Indicates a memory breakpoint instruction was executed, irrespective
891 of whether it was GDB that planted the breakpoint or the breakpoint
892 is hardcoded in the program. This is required for correct non-stop
896 Indicates the target stopped for a hardware breakpoint. This is
897 required for correct non-stop mode operation.
900 Return information about files on the remote system.
903 Return the full absolute name of the file that was executed to
904 create a process running on the remote system.
907 Select the filesystem on which vFile: operations with filename
908 arguments will operate. This is required for GDB to be able to
909 access files on remote targets where the remote stub does not
910 share a common filesystem with the inferior(s).
913 Indicates that a fork system call was executed.
916 Indicates that a vfork system call was executed.
918 vforkdone stop reason
919 Indicates that a vfork child of the specified process has executed
920 an exec or exit, allowing the vfork parent to resume execution.
922 fork-events and vfork-events features in qSupported
923 The qSupported packet allows GDB to request support for fork and
924 vfork events using new 'gdbfeatures' fork-events and vfork-events,
925 and the qSupported response can contain the corresponding
926 'stubfeatures'. Set and show commands can be used to display
927 whether these features are enabled.
929 * Extended-remote fork events
931 ** GDB now has support for fork events on extended-remote Linux
932 targets. For targets with Linux kernels 2.5.60 and later, this
933 enables follow-fork-mode and detach-on-fork for both fork and
934 vfork, as well as fork and vfork catchpoints.
936 * The info record command now shows the recording format and the
937 branch tracing configuration for the current thread when using
938 the btrace record target.
939 For the BTS format, it shows the ring buffer size.
941 * GDB now has support for DTrace USDT (Userland Static Defined
942 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
944 * GDB now supports access to vector registers on S/390 GNU/Linux
947 * Removed command line options
949 -xdb HP-UX XDB compatibility mode.
951 * Removed targets and native configurations
953 HP/PA running HP-UX hppa*-*-hpux*
954 Itanium running HP-UX ia64-*-hpux*
956 * New configure options
959 This configure option allows the user to build GDB with support for
960 Intel Processor Trace (default: auto). This requires libipt.
962 --with-libipt-prefix=PATH
963 Specify the path to the version of libipt that GDB should use.
964 $PATH/include should contain the intel-pt.h header and
965 $PATH/lib should contain the libipt.so library.
967 *** Changes in GDB 7.9.1
971 ** Xmethods can now specify a result type.
973 *** Changes in GDB 7.9
975 * GDB now supports hardware watchpoints on x86 GNU Hurd.
979 ** You can now access frame registers from Python scripts.
980 ** New attribute 'producer' for gdb.Symtab objects.
981 ** gdb.Objfile objects have a new attribute "progspace",
982 which is the gdb.Progspace object of the containing program space.
983 ** gdb.Objfile objects have a new attribute "owner".
984 ** gdb.Objfile objects have a new attribute "build_id",
985 which is the build ID generated when the file was built.
986 ** gdb.Objfile objects have a new method "add_separate_debug_file".
987 ** A new event "gdb.clear_objfiles" has been added, triggered when
988 selecting a new file to debug.
989 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
990 ** New function gdb.lookup_objfile.
992 New events which are triggered when GDB modifies the state of the
995 ** gdb.events.inferior_call_pre: Function call is about to be made.
996 ** gdb.events.inferior_call_post: Function call has just been made.
997 ** gdb.events.memory_changed: A memory location has been altered.
998 ** gdb.events.register_changed: A register has been altered.
1000 * New Python-based convenience functions:
1002 ** $_caller_is(name [, number_of_frames])
1003 ** $_caller_matches(regexp [, number_of_frames])
1004 ** $_any_caller_is(name [, number_of_frames])
1005 ** $_any_caller_matches(regexp [, number_of_frames])
1007 * GDB now supports the compilation and injection of source code into
1008 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1009 to compile the source code to object code, and if successful, inject
1010 and execute that code within the current context of the inferior.
1011 Currently the C language is supported. The commands used to
1012 interface with this new feature are:
1014 compile code [-raw|-r] [--] [source code]
1015 compile file [-raw|-r] filename
1019 demangle [-l language] [--] name
1020 Demangle "name" in the specified language, or the current language
1021 if elided. This command is renamed from the "maint demangle" command.
1022 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1023 as "maint demangler-warning".
1025 queue-signal signal-name-or-number
1026 Queue a signal to be delivered to the thread when it is resumed.
1028 add-auto-load-scripts-directory directory
1029 Add entries to the list of directories from which to load auto-loaded
1032 maint print user-registers
1033 List all currently available "user" registers.
1035 compile code [-r|-raw] [--] [source code]
1036 Compile, inject, and execute in the inferior the executable object
1037 code produced by compiling the provided source code.
1039 compile file [-r|-raw] filename
1040 Compile and inject into the inferior the executable object code
1041 produced by compiling the source code stored in the filename
1044 * On resume, GDB now always passes the signal the program had stopped
1045 for to the thread the signal was sent to, even if the user changed
1046 threads before resuming. Previously GDB would often (but not
1047 always) deliver the signal to the thread that happens to be current
1050 * Conversely, the "signal" command now consistently delivers the
1051 requested signal to the current thread. GDB now asks for
1052 confirmation if the program had stopped for a signal and the user
1053 switched threads meanwhile.
1055 * "breakpoint always-inserted" modes "off" and "auto" merged.
1057 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1058 won't remove breakpoints from the target until all threads stop,
1059 even in non-stop mode. The "auto" mode has been removed, and "off"
1060 is now the default mode.
1064 set debug symbol-lookup
1065 show debug symbol-lookup
1066 Control display of debugging info regarding symbol lookup.
1070 ** The -list-thread-groups command outputs an exit-code field for
1071 inferiors that have exited.
1075 MIPS SDE mips*-sde*-elf*
1079 Support for these obsolete configurations has been removed.
1081 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1082 SGI Irix-5.x mips-*-irix5*
1083 SGI Irix-6.x mips-*-irix6*
1084 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1085 VAX running Ultrix vax-*-ultrix*
1087 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1088 and "assf"), have been removed. Use the "sharedlibrary" command, or
1089 its alias "share", instead.
1091 *** Changes in GDB 7.8
1093 * New command line options
1096 This is an alias for the --data-directory option.
1098 * GDB supports printing and modifying of variable length automatic arrays
1099 as specified in ISO C99.
1101 * The ARM simulator now supports instruction level tracing
1102 with or without disassembly.
1106 GDB now has support for scripting using Guile. Whether this is
1107 available is determined at configure time.
1108 Guile version 2.0 or greater is required.
1109 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1111 * New commands (for set/show, see "New options" below)
1115 Invoke CODE by passing it to the Guile interpreter.
1119 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1121 info auto-load guile-scripts [regexp]
1122 Print the list of automatically loaded Guile scripts.
1124 * The source command is now capable of sourcing Guile scripts.
1125 This feature is dependent on the debugger being built with Guile support.
1129 set print symbol-loading (off|brief|full)
1130 show print symbol-loading
1131 Control whether to print informational messages when loading symbol
1132 information for a file. The default is "full", but when debugging
1133 programs with large numbers of shared libraries the amount of output
1134 becomes less useful.
1136 set guile print-stack (none|message|full)
1137 show guile print-stack
1138 Show a stack trace when an error is encountered in a Guile script.
1140 set auto-load guile-scripts (on|off)
1141 show auto-load guile-scripts
1142 Control auto-loading of Guile script files.
1144 maint ada set ignore-descriptive-types (on|off)
1145 maint ada show ignore-descriptive-types
1146 Control whether the debugger should ignore descriptive types in Ada
1147 programs. The default is not to ignore the descriptive types. See
1148 the user manual for more details on descriptive types and the intended
1149 usage of this option.
1151 set auto-connect-native-target
1153 Control whether GDB is allowed to automatically connect to the
1154 native target for the run, attach, etc. commands when not connected
1155 to any target yet. See also "target native" below.
1157 set record btrace replay-memory-access (read-only|read-write)
1158 show record btrace replay-memory-access
1159 Control what memory accesses are allowed during replay.
1161 maint set target-async (on|off)
1162 maint show target-async
1163 This controls whether GDB targets operate in synchronous or
1164 asynchronous mode. Normally the default is asynchronous, if it is
1165 available; but this can be changed to more easily debug problems
1166 occurring only in synchronous mode.
1168 set mi-async (on|off)
1170 Control whether MI asynchronous mode is preferred. This supersedes
1171 "set target-async" of previous GDB versions.
1173 * "set target-async" is deprecated as a CLI option and is now an alias
1174 for "set mi-async" (only puts MI into async mode).
1176 * Background execution commands (e.g., "c&", "s&", etc.) are now
1177 possible ``out of the box'' if the target supports them. Previously
1178 the user would need to explicitly enable the possibility with the
1179 "set target-async on" command.
1181 * New features in the GDB remote stub, GDBserver
1183 ** New option --debug-format=option1[,option2,...] allows one to add
1184 additional text to each output. At present only timestamps
1185 are supported: --debug-format=timestamps.
1186 Timestamps can also be turned on with the
1187 "monitor set debug-format timestamps" command from GDB.
1189 * The 'record instruction-history' command now starts counting instructions
1190 at one. This also affects the instruction ranges reported by the
1191 'record function-call-history' command when given the /i modifier.
1193 * The command 'record function-call-history' supports a new modifier '/c' to
1194 indent the function names based on their call stack depth.
1195 The fields for the '/i' and '/l' modifier have been reordered.
1196 The source line range is now prefixed with 'at'.
1197 The instruction range is now prefixed with 'inst'.
1198 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1199 "record instruction-history" and "list" commands.
1201 * The ranges given as arguments to the 'record function-call-history' and
1202 'record instruction-history' commands are now inclusive.
1204 * The btrace record target now supports the 'record goto' command.
1205 For locations inside the execution trace, the back trace is computed
1206 based on the information stored in the execution trace.
1208 * The btrace record target supports limited reverse execution and replay.
1209 The target does not record data and therefore does not allow reading
1210 memory or registers.
1212 * The "catch syscall" command now works on s390*-linux* targets.
1214 * The "compare-sections" command is no longer specific to target
1215 remote. It now works with all targets.
1217 * All native targets are now consistently called "native".
1218 Consequently, the "target child", "target GNU", "target djgpp",
1219 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1220 commands have been replaced with "target native". The QNX/NTO port
1221 leaves the "procfs" target in place and adds a "native" target for
1222 consistency with other ports. The impact on users should be minimal
1223 as these commands previously either throwed an error, or were
1224 no-ops. The target's name is visible in the output of the following
1225 commands: "help target", "info target", "info files", "maint print
1228 * The "target native" command now connects to the native target. This
1229 can be used to launch native programs even when "set
1230 auto-connect-native-target" is set to off.
1232 * GDB now supports access to Intel MPX registers on GNU/Linux.
1234 * Support for Intel AVX-512 registers on GNU/Linux.
1235 Support displaying and modifying Intel AVX-512 registers
1236 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1238 * New remote packets
1240 qXfer:btrace:read's annex
1241 The qXfer:btrace:read packet supports a new annex 'delta' to read
1242 branch trace incrementally.
1246 ** Valid Python operations on gdb.Value objects representing
1247 structs/classes invoke the corresponding overloaded operators if
1249 ** New `Xmethods' feature in the Python API. Xmethods are
1250 additional methods or replacements for existing methods of a C++
1251 class. This feature is useful for those cases where a method
1252 defined in C++ source code could be inlined or optimized out by
1253 the compiler, making it unavailable to GDB.
1256 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1258 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1259 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1260 its alias "share", instead.
1262 * The commands "set remotebaud" and "show remotebaud" are no longer
1263 supported. Use "set serial baud" and "show serial baud" (respectively)
1268 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1269 target-async". The latter is left as a deprecated alias of the
1270 former for backward compatibility. If the target supports it,
1271 CLI background execution commands are now always possible by
1272 default, independently of whether the frontend stated a
1273 preference for asynchronous execution with "-gdb-set mi-async".
1274 Previously "-gdb-set target-async off" affected both MI execution
1275 commands and CLI execution commands.
1277 *** Changes in GDB 7.7
1279 * Improved support for process record-replay and reverse debugging on
1280 arm*-linux* targets. Support for thumb32 and syscall instruction
1281 recording has been added.
1283 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1285 * GDB now supports Fission DWP file format version 2.
1286 http://gcc.gnu.org/wiki/DebugFission
1288 * New convenience function "$_isvoid", to check whether an expression
1289 is void. A void expression is an expression where the type of the
1290 result is "void". For example, some convenience variables may be
1291 "void" when evaluated (e.g., "$_exitcode" before the execution of
1292 the program being debugged; or an undefined convenience variable).
1293 Another example, when calling a function whose return type is
1296 * The "maintenance print objfiles" command now takes an optional regexp.
1298 * The "catch syscall" command now works on arm*-linux* targets.
1300 * GDB now consistently shows "<not saved>" when printing values of
1301 registers the debug info indicates have not been saved in the frame
1302 and there's nowhere to retrieve them from
1303 (callee-saved/call-clobbered registers):
1308 (gdb) info registers rax
1311 Before, the former would print "<optimized out>", and the latter
1312 "*value not available*".
1314 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1319 ** Frame filters and frame decorators have been added.
1320 ** Temporary breakpoints are now supported.
1321 ** Line tables representation has been added.
1322 ** New attribute 'parent_type' for gdb.Field objects.
1323 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1324 ** New attribute 'name' for gdb.Type objects.
1328 Nios II ELF nios2*-*-elf
1329 Nios II GNU/Linux nios2*-*-linux
1330 Texas Instruments MSP430 msp430*-*-elf
1332 * Removed native configurations
1334 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1335 been removed. ELF variants of these configurations are kept supported.
1337 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1338 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1339 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1340 i[34567]86-*-openbsd3.[0-3]
1341 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1342 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1343 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1347 Like "catch throw", but catches a re-thrown exception.
1348 maint check-psymtabs
1349 Renamed from old "maint check-symtabs".
1351 Perform consistency checks on symtabs.
1352 maint expand-symtabs
1353 Expand symtabs matching an optional regexp.
1356 Display the details of GDB configure-time options.
1358 maint set|show per-command
1359 maint set|show per-command space
1360 maint set|show per-command time
1361 maint set|show per-command symtab
1362 Enable display of per-command gdb resource usage.
1364 remove-symbol-file FILENAME
1365 remove-symbol-file -a ADDRESS
1366 Remove a symbol file added via add-symbol-file. The file to remove
1367 can be identified by its filename or by an address that lies within
1368 the boundaries of this symbol file in memory.
1371 info exceptions REGEXP
1372 Display the list of Ada exceptions defined in the program being
1373 debugged. If provided, only the exceptions whose names match REGEXP
1378 set debug symfile off|on
1380 Control display of debugging info regarding reading symbol files and
1381 symbol tables within those files
1383 set print raw frame-arguments
1384 show print raw frame-arguments
1385 Set/show whether to print frame arguments in raw mode,
1386 disregarding any defined pretty-printers.
1388 set remote trace-status-packet
1389 show remote trace-status-packet
1390 Set/show the use of remote protocol qTStatus packet.
1394 Control display of debugging messages related to Nios II targets.
1398 Control whether target-assisted range stepping is enabled.
1400 set startup-with-shell
1401 show startup-with-shell
1402 Specifies whether Unix child processes are started via a shell or
1407 Use the target memory cache for accesses to the code segment. This
1408 improves performance of remote debugging (particularly disassembly).
1410 * You can now use a literal value 'unlimited' for options that
1411 interpret 0 or -1 as meaning "unlimited". E.g., "set
1412 trace-buffer-size unlimited" is now an alias for "set
1413 trace-buffer-size -1" and "set height unlimited" is now an alias for
1416 * The "set debug symtab-create" debugging option of GDB has been changed to
1417 accept a verbosity level. 0 means "off", 1 provides basic debugging
1418 output, and values of 2 or greater provides more verbose output.
1420 * New command-line options
1422 Display the details of GDB configure-time options.
1424 * The command 'tsave' can now support new option '-ctf' to save trace
1425 buffer in Common Trace Format.
1427 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1430 * GDB now implements the the C++ 'typeid' operator.
1432 * The new convenience variable $_exception holds the exception being
1433 thrown or caught at an exception-related catchpoint.
1435 * The exception-related catchpoints, like "catch throw", now accept a
1436 regular expression which can be used to filter exceptions by type.
1438 * The new convenience variable $_exitsignal is automatically set to
1439 the terminating signal number when the program being debugged dies
1440 due to an uncaught signal.
1444 ** All MI commands now accept an optional "--language" option.
1445 Support for this feature can be verified by using the "-list-features"
1446 command, which should contain "language-option".
1448 ** The new command -info-gdb-mi-command allows the user to determine
1449 whether a GDB/MI command is supported or not.
1451 ** The "^error" result record returned when trying to execute an undefined
1452 GDB/MI command now provides a variable named "code" whose content is the
1453 "undefined-command" error code. Support for this feature can be verified
1454 by using the "-list-features" command, which should contain
1455 "undefined-command-error-code".
1457 ** The -trace-save MI command can optionally save trace buffer in Common
1460 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1462 ** The command -data-list-register-values now accepts an optional
1463 "--skip-unavailable" option. When used, only the available registers
1466 ** The new command -trace-frame-collected dumps collected variables,
1467 computed expressions, tvars, memory and registers in a traceframe.
1469 ** The commands -stack-list-locals, -stack-list-arguments and
1470 -stack-list-variables now accept an option "--skip-unavailable".
1471 When used, only the available locals or arguments are displayed.
1473 ** The -exec-run command now accepts an optional "--start" option.
1474 When used, the command follows the same semantics as the "start"
1475 command, stopping the program's execution at the start of its
1476 main subprogram. Support for this feature can be verified using
1477 the "-list-features" command, which should contain
1478 "exec-run-start-option".
1480 ** The new commands -catch-assert and -catch-exceptions insert
1481 catchpoints stopping the program when Ada exceptions are raised.
1483 ** The new command -info-ada-exceptions provides the equivalent of
1484 the new "info exceptions" command.
1486 * New system-wide configuration scripts
1487 A GDB installation now provides scripts suitable for use as system-wide
1488 configuration scripts for the following systems:
1492 * GDB now supports target-assigned range stepping with remote targets.
1493 This improves the performance of stepping source lines by reducing
1494 the number of control packets from/to GDB. See "New remote packets"
1497 * GDB now understands the element 'tvar' in the XML traceframe info.
1498 It has the id of the collected trace state variables.
1500 * On S/390 targets that provide the transactional-execution feature,
1501 the program interruption transaction diagnostic block (TDB) is now
1502 represented as a number of additional "registers" in GDB.
1504 * New remote packets
1508 The vCont packet supports a new 'r' action, that tells the remote
1509 stub to step through an address range itself, without GDB
1510 involvemement at each single-step.
1512 qXfer:libraries-svr4:read's annex
1513 The previously unused annex of the qXfer:libraries-svr4:read packet
1514 is now used to support passing an argument list. The remote stub
1515 reports support for this argument list to GDB's qSupported query.
1516 The defined arguments are "start" and "prev", used to reduce work
1517 necessary for library list updating, resulting in significant
1520 * New features in the GDB remote stub, GDBserver
1522 ** GDBserver now supports target-assisted range stepping. Currently
1523 enabled on x86/x86_64 GNU/Linux targets.
1525 ** GDBserver now adds element 'tvar' in the XML in the reply to
1526 'qXfer:traceframe-info:read'. It has the id of the collected
1527 trace state variables.
1529 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1532 * New 'z' formatter for printing and examining memory, this displays the
1533 value as hexadecimal zero padded on the left to the size of the type.
1535 * GDB can now use Windows x64 unwinding data.
1537 * The "set remotebaud" command has been replaced by "set serial baud".
1538 Similarly, "show remotebaud" has been replaced by "show serial baud".
1539 The "set remotebaud" and "show remotebaud" commands are still available
1540 to provide backward compatibility with older versions of GDB.
1542 *** Changes in GDB 7.6
1544 * Target record has been renamed to record-full.
1545 Record/replay is now enabled with the "record full" command.
1546 This also affects settings that are associated with full record/replay
1547 that have been moved from "set/show record" to "set/show record full":
1549 set|show record full insn-number-max
1550 set|show record full stop-at-limit
1551 set|show record full memory-query
1553 * A new record target "record-btrace" has been added. The new target
1554 uses hardware support to record the control-flow of a process. It
1555 does not support replaying the execution, but it implements the
1556 below new commands for investigating the recorded execution log.
1557 This new recording method can be enabled using:
1561 The "record-btrace" target is only available on Intel Atom processors
1562 and requires a Linux kernel 2.6.32 or later.
1564 * Two new commands have been added for record/replay to give information
1565 about the recorded execution without having to replay the execution.
1566 The commands are only supported by "record btrace".
1568 record instruction-history prints the execution history at
1569 instruction granularity
1571 record function-call-history prints the execution history at
1572 function granularity
1574 * New native configurations
1576 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1577 FreeBSD/powerpc powerpc*-*-freebsd
1578 x86_64/Cygwin x86_64-*-cygwin*
1579 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1583 ARM AArch64 aarch64*-*-elf
1584 ARM AArch64 GNU/Linux aarch64*-*-linux
1585 Lynx 178 PowerPC powerpc-*-lynx*178
1586 x86_64/Cygwin x86_64-*-cygwin*
1587 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1589 * If the configured location of system.gdbinit file (as given by the
1590 --with-system-gdbinit option at configure time) is in the
1591 data-directory (as specified by --with-gdb-datadir at configure
1592 time) or in one of its subdirectories, then GDB will look for the
1593 system-wide init file in the directory specified by the
1594 --data-directory command-line option.
1596 * New command line options:
1598 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1599 other initialization files, unlike -nx which disables all of them.
1601 * Removed command line options
1603 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1606 * The 'ptype' and 'whatis' commands now accept an argument to control
1609 * 'info proc' now works on some core files.
1613 ** Vectors can be created with gdb.Type.vector.
1615 ** Python's atexit.register now works in GDB.
1617 ** Types can be pretty-printed via a Python API.
1619 ** Python 3 is now supported (in addition to Python 2.4 or later)
1621 ** New class gdb.Architecture exposes GDB's internal representation
1622 of architecture in the Python API.
1624 ** New method Frame.architecture returns the gdb.Architecture object
1625 corresponding to the frame's architecture.
1627 * New Python-based convenience functions:
1629 ** $_memeq(buf1, buf2, length)
1630 ** $_streq(str1, str2)
1632 ** $_regex(str, regex)
1634 * The 'cd' command now defaults to using '~' (the home directory) if not
1637 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1638 default for GCC since November 2000.
1640 * The command 'forward-search' can now be abbreviated as 'fo'.
1642 * The command 'info tracepoints' can now display 'installed on target'
1643 or 'not installed on target' for each non-pending location of tracepoint.
1645 * New configure options
1647 --enable-libmcheck/--disable-libmcheck
1648 By default, development versions are built with -lmcheck on hosts
1649 that support it, in order to help track memory corruption issues.
1650 Release versions, on the other hand, are built without -lmcheck
1651 by default. The --enable-libmcheck/--disable-libmcheck configure
1652 options allow the user to override that default.
1653 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1654 This configure option allows the user to build GDB with
1655 libbabeltrace using which GDB can read Common Trace Format data.
1657 * New commands (for set/show, see "New options" below)
1660 Catch signals. This is similar to "handle", but allows commands and
1661 conditions to be attached.
1664 List the BFDs known to GDB.
1666 python-interactive [command]
1668 Start a Python interactive prompt, or evaluate the optional command
1669 and print the result of expressions.
1672 "py" is a new alias for "python".
1674 enable type-printer [name]...
1675 disable type-printer [name]...
1676 Enable or disable type printers.
1680 ** For the Renesas Super-H architecture, the "regs" command has been removed
1681 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1686 set print type methods (on|off)
1687 show print type methods
1688 Control whether method declarations are displayed by "ptype".
1689 The default is to show them.
1691 set print type typedefs (on|off)
1692 show print type typedefs
1693 Control whether typedef definitions are displayed by "ptype".
1694 The default is to show them.
1696 set filename-display basename|relative|absolute
1697 show filename-display
1698 Control the way in which filenames is displayed.
1699 The default is "relative", which preserves previous behavior.
1701 set trace-buffer-size
1702 show trace-buffer-size
1703 Request target to change the size of trace buffer.
1705 set remote trace-buffer-size-packet auto|on|off
1706 show remote trace-buffer-size-packet
1707 Control the use of the remote protocol `QTBuffer:size' packet.
1711 Control display of debugging messages related to ARM AArch64.
1714 set debug coff-pe-read
1715 show debug coff-pe-read
1716 Control display of debugging messages related to reading of COFF/PE
1721 Control display of debugging messages related to Mach-O symbols
1724 set debug notification
1725 show debug notification
1726 Control display of debugging info for async remote notification.
1730 ** Command parameter changes are now notified using new async record
1731 "=cmd-param-changed".
1732 ** Trace frame changes caused by command "tfind" are now notified using
1733 new async record "=traceframe-changed".
1734 ** The creation, deletion and modification of trace state variables
1735 are now notified using new async records "=tsv-created",
1736 "=tsv-deleted" and "=tsv-modified".
1737 ** The start and stop of process record are now notified using new
1738 async record "=record-started" and "=record-stopped".
1739 ** Memory changes are now notified using new async record
1741 ** The data-disassemble command response will include a "fullname" field
1742 containing the absolute file name when source has been requested.
1743 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1744 command, to allow pattern filling of memory areas.
1745 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1746 library load/unload events.
1747 ** The response to breakpoint commands and breakpoint async records
1748 includes an "installed" field containing a boolean state about each
1749 non-pending tracepoint location is whether installed on target or not.
1750 ** Output of the "-trace-status" command includes a "trace-file" field
1751 containing the name of the trace file being examined. This field is
1752 optional, and only present when examining a trace file.
1753 ** The "fullname" field is now always present along with the "file" field,
1754 even if the file cannot be found by GDB.
1756 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1757 You must have the LZMA library available when configuring GDB for this
1758 feature to be enabled. For more information, see:
1759 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1761 * New remote packets
1764 Set the size of trace buffer. The remote stub reports support for this
1765 packet to gdb's qSupported query.
1768 Enable Branch Trace Store (BTS)-based branch tracing for the current
1769 thread. The remote stub reports support for this packet to gdb's
1773 Disable branch tracing for the current thread. The remote stub reports
1774 support for this packet to gdb's qSupported query.
1777 Read the traced branches for the current thread. The remote stub
1778 reports support for this packet to gdb's qSupported query.
1780 *** Changes in GDB 7.5
1782 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1783 for more x32 ABI info.
1785 * GDB now supports access to MIPS DSP registers on Linux targets.
1787 * GDB now supports debugging microMIPS binaries.
1789 * The "info os" command on GNU/Linux can now display information on
1790 several new classes of objects managed by the operating system:
1791 "info os procgroups" lists process groups
1792 "info os files" lists file descriptors
1793 "info os sockets" lists internet-domain sockets
1794 "info os shm" lists shared-memory regions
1795 "info os semaphores" lists semaphores
1796 "info os msg" lists message queues
1797 "info os modules" lists loaded kernel modules
1799 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1800 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1801 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1802 options and inspect the probe arguments using the new $_probe_arg family
1803 of convenience variables. You can obtain more information about SystemTap
1804 in <http://sourceware.org/systemtap/>.
1806 * GDB now supports reversible debugging on ARM, it allows you to
1807 debug basic ARM and THUMB instructions, and provides
1808 record/replay support.
1810 * The option "symbol-reloading" has been deleted as it is no longer used.
1814 ** GDB commands implemented in Python can now be put in command class
1817 ** The "maint set python print-stack on|off" is now deleted.
1819 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1820 apply "flag enum"-style pretty-printing to any enum.
1822 ** gdb.lookup_symbol can now work when there is no current frame.
1824 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1825 the source at which the symbol was defined.
1827 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1828 method 'value'. The former indicates whether the symbol needs a
1829 frame in order to compute its value, and the latter computes the
1832 ** A new method 'referenced_value' on gdb.Value objects which can
1833 dereference pointer as well as C++ reference values.
1835 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1836 which return the global and static blocks (as gdb.Block objects),
1837 of the underlying symbol table, respectively.
1839 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1840 object associated with a PC value.
1842 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1843 of the address range occupied by code for the current source line.
1845 * Go language support.
1846 GDB now supports debugging programs written in the Go programming
1849 * GDBserver now supports stdio connections.
1850 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1852 * The binary "gdbtui" can no longer be built or installed.
1853 Use "gdb -tui" instead.
1855 * GDB will now print "flag" enums specially. A flag enum is one where
1856 all the enumerator values have no bits in common when pairwise
1857 "and"ed. When printing a value whose type is a flag enum, GDB will
1858 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1859 (gdb) print (enum E) 3
1862 * The filename part of a linespec will now match trailing components
1863 of a source file name. For example, "break gcc/expr.c:1000" will
1864 now set a breakpoint in build/gcc/expr.c, but not
1865 build/libcpp/expr.c.
1867 * The "info proc" and "generate-core-file" commands will now also
1868 work on remote targets connected to GDBserver on Linux.
1870 * The command "info catch" has been removed. It has been disabled
1871 since December 2007.
1873 * The "catch exception" and "catch assert" commands now accept
1874 a condition at the end of the command, much like the "break"
1875 command does. For instance:
1877 (gdb) catch exception Constraint_Error if Barrier = True
1879 Previously, it was possible to add a condition to such catchpoints,
1880 but it had to be done as a second step, after the catchpoint had been
1881 created, using the "condition" command.
1883 * The "info static-tracepoint-marker" command will now also work on
1884 native Linux targets with in-process agent.
1886 * GDB can now set breakpoints on inlined functions.
1888 * The .gdb_index section has been updated to include symbols for
1889 inlined functions. GDB will ignore older .gdb_index sections by
1890 default, which could cause symbol files to be loaded more slowly
1891 until their .gdb_index sections can be recreated. The new command
1892 "set use-deprecated-index-sections on" will cause GDB to use any older
1893 .gdb_index sections it finds. This will restore performance, but the
1894 ability to set breakpoints on inlined functions will be lost in symbol
1895 files with older .gdb_index sections.
1897 The .gdb_index section has also been updated to record more information
1898 about each symbol. This speeds up the "info variables", "info functions"
1899 and "info types" commands when used with programs having the .gdb_index
1900 section, as well as speeding up debugging with shared libraries using
1901 the .gdb_index section.
1903 * Ada support for GDB/MI Variable Objects has been added.
1905 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1910 ** New command -info-os is the MI equivalent of "info os".
1912 ** Output logs ("set logging" and related) now include MI output.
1916 ** "set use-deprecated-index-sections on|off"
1917 "show use-deprecated-index-sections on|off"
1918 Controls the use of deprecated .gdb_index sections.
1920 ** "catch load" and "catch unload" can be used to stop when a shared
1921 library is loaded or unloaded, respectively.
1923 ** "enable count" can be used to auto-disable a breakpoint after
1926 ** "info vtbl" can be used to show the virtual method tables for
1927 C++ and Java objects.
1929 ** "explore" and its sub commands "explore value" and "explore type"
1930 can be used to recursively explore values and types of
1931 expressions. These commands are available only if GDB is
1932 configured with '--with-python'.
1934 ** "info auto-load" shows status of all kinds of auto-loaded files,
1935 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1936 sequences of commands files, "info auto-load python-scripts"
1937 shows status of auto-loading Python script files,
1938 "info auto-load local-gdbinit" shows status of loading init file
1939 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1940 status of inferior specific thread debugging shared library loading.
1942 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1943 and "show auto-load-scripts" commands have been deprecated, use their
1944 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1945 and "show auto-load python-scripts" counterparts instead.
1947 ** "dprintf location,format,args..." creates a dynamic printf, which
1948 is basically a breakpoint that does a printf and immediately
1949 resumes your program's execution, so it is like a printf that you
1950 can insert dynamically at runtime instead of at compiletime.
1952 ** "set print symbol"
1954 Controls whether GDB attempts to display the symbol, if any,
1955 corresponding to addresses it prints. This defaults to "on", but
1956 you can set it to "off" to restore GDB's previous behavior.
1958 * Deprecated commands
1960 ** For the Renesas Super-H architecture, the "regs" command has been
1961 deprecated, and "info all-registers" should be used instead.
1965 Renesas RL78 rl78-*-elf
1966 HP OpenVMS ia64 ia64-hp-openvms*
1968 * GDBserver supports evaluation of breakpoint conditions. When
1969 support is advertised by GDBserver, GDB may be told to send the
1970 breakpoint conditions in bytecode form to GDBserver. GDBserver
1971 will only report the breakpoint trigger to GDB when its condition
1976 set mips compression
1977 show mips compression
1978 Select the compressed ISA encoding used in functions that have no symbol
1979 information available. The encoding can be set to either of:
1982 and is updated automatically from ELF file flags if available.
1984 set breakpoint condition-evaluation
1985 show breakpoint condition-evaluation
1986 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1987 GDBserver ("target"). Default option "auto" chooses the most efficient
1989 This option can improve debugger efficiency depending on the speed of the
1993 Disable auto-loading globally.
1996 Show auto-loading setting of all kinds of auto-loaded files.
1998 set auto-load gdb-scripts on|off
1999 show auto-load gdb-scripts
2000 Control auto-loading of GDB canned sequences of commands files.
2002 set auto-load python-scripts on|off
2003 show auto-load python-scripts
2004 Control auto-loading of Python script files.
2006 set auto-load local-gdbinit on|off
2007 show auto-load local-gdbinit
2008 Control loading of init file (.gdbinit) from current directory.
2010 set auto-load libthread-db on|off
2011 show auto-load libthread-db
2012 Control auto-loading of inferior specific thread debugging shared library.
2014 set auto-load scripts-directory <dir1>[:<dir2>...]
2015 show auto-load scripts-directory
2016 Set a list of directories from which to load auto-loaded scripts.
2017 Automatically loaded Python scripts and GDB scripts are located in one
2018 of the directories listed by this option.
2019 The delimiter (':' above) may differ according to the host platform.
2021 set auto-load safe-path <dir1>[:<dir2>...]
2022 show auto-load safe-path
2023 Set a list of directories from which it is safe to auto-load files.
2024 The delimiter (':' above) may differ according to the host platform.
2026 set debug auto-load on|off
2027 show debug auto-load
2028 Control display of debugging info for auto-loading the files above.
2030 set dprintf-style gdb|call|agent
2032 Control the way in which a dynamic printf is performed; "gdb"
2033 requests a GDB printf command, while "call" causes dprintf to call a
2034 function in the inferior. "agent" requests that the target agent
2035 (such as GDBserver) do the printing.
2037 set dprintf-function <expr>
2038 show dprintf-function
2039 set dprintf-channel <expr>
2040 show dprintf-channel
2041 Set the function and optional first argument to the call when using
2042 the "call" style of dynamic printf.
2044 set disconnected-dprintf on|off
2045 show disconnected-dprintf
2046 Control whether agent-style dynamic printfs continue to be in effect
2047 after GDB disconnects.
2049 * New configure options
2051 --with-auto-load-dir
2052 Configure default value for the 'set auto-load scripts-directory'
2053 setting above. It defaults to '$debugdir:$datadir/auto-load',
2054 $debugdir representing global debugging info directories (available
2055 via 'show debug-file-directory') and $datadir representing GDB's data
2056 directory (available via 'show data-directory').
2058 --with-auto-load-safe-path
2059 Configure default value for the 'set auto-load safe-path' setting
2060 above. It defaults to the --with-auto-load-dir setting.
2062 --without-auto-load-safe-path
2063 Set 'set auto-load safe-path' to '/', effectively disabling this
2066 * New remote packets
2068 z0/z1 conditional breakpoints extension
2070 The z0/z1 breakpoint insertion packets have been extended to carry
2071 a list of conditional expressions over to the remote stub depending on the
2072 condition evaluation mode. The use of this extension can be controlled
2073 via the "set remote conditional-breakpoints-packet" command.
2077 Specify the signals which the remote stub may pass to the debugged
2078 program without GDB involvement.
2080 * New command line options
2082 --init-command=FILE, -ix Like --command, -x but execute it
2083 before loading inferior.
2084 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2085 execute it before loading inferior.
2087 *** Changes in GDB 7.4
2089 * GDB now handles ambiguous linespecs more consistently; the existing
2090 FILE:LINE support has been expanded to other types of linespecs. A
2091 breakpoint will now be set on all matching locations in all
2092 inferiors, and locations will be added or removed according to
2095 * GDB now allows you to skip uninteresting functions and files when
2096 stepping with the "skip function" and "skip file" commands.
2098 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2099 and "show remote hardware-watchpoint-length-limit". These allows to
2100 set or show the maximum length limit (in bytes) of a remote
2101 target hardware watchpoint.
2103 This allows e.g. to use "unlimited" hardware watchpoints with the
2104 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2105 watchpoints are slower than real hardware watchpoints but are
2106 significantly faster than gdb software watchpoints.
2110 ** The register_pretty_printer function in module gdb.printing now takes
2111 an optional `replace' argument. If True, the new printer replaces any
2114 ** The "maint set python print-stack on|off" command has been
2115 deprecated and will be deleted in GDB 7.5.
2116 A new command: "set python print-stack none|full|message" has
2117 replaced it. Additionally, the default for "print-stack" is
2118 now "message", which just prints the error message without
2121 ** A prompt substitution hook (prompt_hook) is now available to the
2124 ** A new Python module, gdb.prompt has been added to the GDB Python
2125 modules library. This module provides functionality for
2126 escape sequences in prompts (used by set/show
2127 extended-prompt). These escape sequences are replaced by their
2128 corresponding value.
2130 ** Python commands and convenience-functions located in
2131 'data-directory'/python/gdb/command and
2132 'data-directory'/python/gdb/function are now automatically loaded
2135 ** Blocks now provide four new attributes. global_block and
2136 static_block will return the global and static blocks
2137 respectively. is_static and is_global are boolean attributes
2138 that indicate if the block is one of those two types.
2140 ** Symbols now provide the "type" attribute, the type of the symbol.
2142 ** The "gdb.breakpoint" function has been deprecated in favor of
2145 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2146 of a function. This class is based on the "finish" command
2147 available in the CLI.
2149 ** Type objects for struct and union types now allow access to
2150 the fields using standard Python dictionary (mapping) methods.
2151 For example, "some_type['myfield']" now works, as does
2152 "some_type.items()".
2154 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2157 ** A new function, "deep_items" has been added to the gdb.types
2158 module in the GDB Python modules library. This function returns
2159 an iterator over the fields of a struct or union type. Unlike
2160 the standard Python "iteritems" method, it will recursively traverse
2161 any anonymous fields.
2165 ** "*stopped" events can report several new "reason"s, such as
2168 ** Breakpoint changes are now notified using new async records, like
2169 "=breakpoint-modified".
2171 ** New command -ada-task-info.
2173 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2174 $sdir specifies the default system locations of shared libraries.
2175 $pdir specifies the directory where the libpthread used by the application
2178 GDB no longer looks in $sdir and $pdir after it has searched the directories
2179 mentioned in libthread-db-search-path. If you want to search those
2180 directories, they must be specified in libthread-db-search-path.
2181 The default value of libthread-db-search-path on GNU/Linux and Solaris
2182 systems is now "$sdir:$pdir".
2184 $pdir is not supported by gdbserver, it is currently ignored.
2185 $sdir is supported by gdbserver.
2187 * New configure option --with-iconv-bin.
2188 When using the internationalization support like the one in the GNU C
2189 library, GDB will invoke the "iconv" program to get a list of supported
2190 character sets. If this program lives in a non-standard location, one can
2191 use this option to specify where to find it.
2193 * When natively debugging programs on PowerPC BookE processors running
2194 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2195 watchpoints, which specify a mask in addition to an address to watch.
2196 The mask specifies that some bits of an address (the bits which are
2197 reset in the mask) should be ignored when matching the address accessed
2198 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2199 section in the user manual for more details.
2201 * The new option --once causes GDBserver to stop listening for connections once
2202 the first connection is made. The listening port used by GDBserver will
2203 become available after that.
2205 * New commands "info macros" and "alias" have been added.
2207 * New function parameters suffix @entry specifies value of function parameter
2208 at the time the function got called. Entry values are available only since
2214 "!" is now an alias of the "shell" command.
2215 Note that no space is needed between "!" and SHELL COMMAND.
2219 watch EXPRESSION mask MASK_VALUE
2220 The watch command now supports the mask argument which allows creation
2221 of masked watchpoints, if the current architecture supports this feature.
2223 info auto-load-scripts [REGEXP]
2224 This command was formerly named "maintenance print section-scripts".
2225 It is now generally useful and is no longer a maintenance-only command.
2227 info macro [-all] [--] MACRO
2228 The info macro command has new options `-all' and `--'. The first for
2229 printing all definitions of a macro. The second for explicitly specifying
2230 the end of arguments and the beginning of the macro name in case the macro
2231 name starts with a hyphen.
2233 collect[/s] EXPRESSIONS
2234 The tracepoint collect command now takes an optional modifier "/s"
2235 that directs it to dereference pointer-to-character types and
2236 collect the bytes of memory up to a zero byte. The behavior is
2237 similar to what you see when you use the regular print command on a
2238 string. An optional integer following the "/s" sets a bound on the
2239 number of bytes that will be collected.
2242 The trace start command now interprets any supplied arguments as a
2243 note to be recorded with the trace run, with an effect similar to
2244 setting the variable trace-notes.
2247 The trace stop command now interprets any arguments as a note to be
2248 mentioned along with the tstatus report that the trace was stopped
2249 with a command. The effect is similar to setting the variable
2252 * Tracepoints can now be enabled and disabled at any time after a trace
2253 experiment has been started using the standard "enable" and "disable"
2254 commands. It is now possible to start a trace experiment with no enabled
2255 tracepoints; GDB will display a warning, but will allow the experiment to
2256 begin, assuming that tracepoints will be enabled as needed while the trace
2259 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2260 locations with 4-byte instructions, when they were previously
2261 limited to locations with instructions of 5 bytes or longer.
2265 set debug dwarf2-read
2266 show debug dwarf2-read
2267 Turns on or off display of debugging messages related to reading
2268 DWARF debug info. The default is off.
2270 set debug symtab-create
2271 show debug symtab-create
2272 Turns on or off display of debugging messages related to symbol table
2273 creation. The default is off.
2276 show extended-prompt
2277 Set the GDB prompt, and allow escape sequences to be inserted to
2278 display miscellaneous information (see 'help set extended-prompt'
2279 for the list of sequences). This prompt (and any information
2280 accessed through the escape sequences) is updated every time the
2281 prompt is displayed.
2283 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2284 show print entry-values
2285 Set printing of frame argument values at function entry. In some cases
2286 GDB can determine the value of function argument which was passed by the
2287 function caller, even if the value was modified inside the called function.
2289 set debug entry-values
2290 show debug entry-values
2291 Control display of debugging info for determining frame argument values at
2292 function entry and virtual tail call frames.
2294 set basenames-may-differ
2295 show basenames-may-differ
2296 Set whether a source file may have multiple base names.
2297 (A "base name" is the name of a file with the directory part removed.
2298 Example: The base name of "/home/user/hello.c" is "hello.c".)
2299 If set, GDB will canonicalize file names (e.g., expand symlinks)
2300 before comparing them. Canonicalization is an expensive operation,
2301 but it allows the same file be known by more than one base name.
2302 If not set (the default), all source files are assumed to have just
2303 one base name, and gdb will do file name comparisons more efficiently.
2309 Set a user name and notes for the current and any future trace runs.
2310 This is useful for long-running and/or disconnected traces, to
2311 inform others (or yourself) as to who is running the trace, supply
2312 contact information, or otherwise explain what is going on.
2314 set trace-stop-notes
2315 show trace-stop-notes
2316 Set a note attached to the trace run, that is displayed when the
2317 trace has been stopped by a tstop command. This is useful for
2318 instance as an explanation, if you are stopping a trace run that was
2319 started by someone else.
2321 * New remote packets
2325 Dynamically enable a tracepoint in a started trace experiment.
2329 Dynamically disable a tracepoint in a started trace experiment.
2333 Set the user and notes of the trace run.
2337 Query the current status of a tracepoint.
2341 Query the minimum length of instruction at which a fast tracepoint may
2344 * Dcache size (number of lines) and line-size are now runtime-configurable
2345 via "set dcache line" and "set dcache line-size" commands.
2349 Texas Instruments TMS320C6x tic6x-*-*
2353 Renesas RL78 rl78-*-elf
2355 *** Changes in GDB 7.3.1
2357 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2359 *** Changes in GDB 7.3
2361 * GDB has a new command: "thread find [REGEXP]".
2362 It finds the thread id whose name, target id, or thread extra info
2363 matches the given regular expression.
2365 * The "catch syscall" command now works on mips*-linux* targets.
2367 * The -data-disassemble MI command now supports modes 2 and 3 for
2368 dumping the instruction opcodes.
2370 * New command line options
2372 -data-directory DIR Specify DIR as the "data-directory".
2373 This is mostly for testing purposes.
2375 * The "maint set python auto-load on|off" command has been renamed to
2376 "set auto-load-scripts on|off".
2378 * GDB has a new command: "set directories".
2379 It is like the "dir" command except that it replaces the
2380 source path list instead of augmenting it.
2382 * GDB now understands thread names.
2384 On GNU/Linux, "info threads" will display the thread name as set by
2385 prctl or pthread_setname_np.
2387 There is also a new command, "thread name", which can be used to
2388 assign a name internally for GDB to display.
2391 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2392 has been integrated into GDB.
2396 ** The function gdb.Write now accepts an optional keyword 'stream'.
2397 This keyword, when provided, will direct the output to either
2398 stdout, stderr, or GDB's logging output.
2400 ** Parameters can now be be sub-classed in Python, and in particular
2401 you may implement the get_set_doc and get_show_doc functions.
2402 This improves how Parameter set/show documentation is processed
2403 and allows for more dynamic content.
2405 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2406 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2407 have an is_valid method.
2409 ** Breakpoints can now be sub-classed in Python, and in particular
2410 you may implement a 'stop' function that is executed each time
2411 the inferior reaches that breakpoint.
2413 ** New function gdb.lookup_global_symbol looks up a global symbol.
2415 ** GDB values in Python are now callable if the value represents a
2416 function. For example, if 'some_value' represents a function that
2417 takes two integer parameters and returns a value, you can call
2418 that function like so:
2420 result = some_value (10,20)
2422 ** Module gdb.types has been added.
2423 It contains a collection of utilities for working with gdb.Types objects:
2424 get_basic_type, has_field, make_enum_dict.
2426 ** Module gdb.printing has been added.
2427 It contains utilities for writing and registering pretty-printers.
2428 New classes: PrettyPrinter, SubPrettyPrinter,
2429 RegexpCollectionPrettyPrinter.
2430 New function: register_pretty_printer.
2432 ** New commands "info pretty-printers", "enable pretty-printer" and
2433 "disable pretty-printer" have been added.
2435 ** gdb.parameter("directories") is now available.
2437 ** New function gdb.newest_frame returns the newest frame in the
2440 ** The gdb.InferiorThread class has a new "name" attribute. This
2441 holds the thread's name.
2443 ** Python Support for Inferior events.
2444 Python scripts can add observers to be notified of events
2445 occurring in the process being debugged.
2446 The following events are currently supported:
2447 - gdb.events.cont Continue event.
2448 - gdb.events.exited Inferior exited event.
2449 - gdb.events.stop Signal received, and Breakpoint hit events.
2453 ** GDB now puts template parameters in scope when debugging in an
2454 instantiation. For example, if you have:
2456 template<int X> int func (void) { return X; }
2458 then if you step into func<5>, "print X" will show "5". This
2459 feature requires proper debuginfo support from the compiler; it
2460 was added to GCC 4.5.
2462 ** The motion commands "next", "finish", "until", and "advance" now
2463 work better when exceptions are thrown. In particular, GDB will
2464 no longer lose control of the inferior; instead, the GDB will
2465 stop the inferior at the point at which the exception is caught.
2466 This functionality requires a change in the exception handling
2467 code that was introduced in GCC 4.5.
2469 * GDB now follows GCC's rules on accessing volatile objects when
2470 reading or writing target state during expression evaluation.
2471 One notable difference to prior behavior is that "print x = 0"
2472 no longer generates a read of x; the value of the assignment is
2473 now always taken directly from the value being assigned.
2475 * GDB now has some support for using labels in the program's source in
2476 linespecs. For instance, you can use "advance label" to continue
2477 execution to a label.
2479 * GDB now has support for reading and writing a new .gdb_index
2480 section. This section holds a fast index of DWARF debugging
2481 information and can be used to greatly speed up GDB startup and
2482 operation. See the documentation for `save gdb-index' for details.
2484 * The "watch" command now accepts an optional "-location" argument.
2485 When used, this causes GDB to watch the memory referred to by the
2486 expression. Such a watchpoint is never deleted due to it going out
2489 * GDB now supports thread debugging of core dumps on GNU/Linux.
2491 GDB now activates thread debugging using the libthread_db library
2492 when debugging GNU/Linux core dumps, similarly to when debugging
2493 live processes. As a result, when debugging a core dump file, GDB
2494 is now able to display pthread_t ids of threads. For example, "info
2495 threads" shows the same output as when debugging the process when it
2496 was live. In earlier releases, you'd see something like this:
2499 * 1 LWP 6780 main () at main.c:10
2501 While now you see this:
2504 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2506 It is also now possible to inspect TLS variables when debugging core
2509 When debugging a core dump generated on a machine other than the one
2510 used to run GDB, you may need to point GDB at the correct
2511 libthread_db library with the "set libthread-db-search-path"
2512 command. See the user manual for more details on this command.
2514 * When natively debugging programs on PowerPC BookE processors running
2515 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2516 which stop execution of the inferior whenever it executes an instruction
2517 at any address within the specified range. See the "PowerPC Embedded"
2518 section in the user manual for more details.
2520 * New features in the GDB remote stub, GDBserver
2522 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2523 and i686 LynxOS (version 5.x).
2525 ** GDBserver is now supported on Blackfin Linux.
2527 * New native configurations
2529 ia64 HP-UX ia64-*-hpux*
2533 Analog Devices, Inc. Blackfin Processor bfin-*
2535 * Ada task switching is now supported on sparc-elf targets when
2536 debugging a program using the Ravenscar Profile. For more information,
2537 see the "Tasking Support when using the Ravenscar Profile" section
2538 in the GDB user manual.
2540 * Guile support was removed.
2542 * New features in the GNU simulator
2544 ** The --map-info flag lists all known core mappings.
2546 ** CFI flashes may be simulated via the "cfi" device.
2548 *** Changes in GDB 7.2
2550 * Shared library support for remote targets by default
2552 When GDB is configured for a generic, non-OS specific target, like
2553 for example, --target=arm-eabi or one of the many *-*-elf targets,
2554 GDB now queries remote stubs for loaded shared libraries using the
2555 `qXfer:libraries:read' packet. Previously, shared library support
2556 was always disabled for such configurations.
2560 ** Argument Dependent Lookup (ADL)
2562 In C++ ADL lookup directs function search to the namespaces of its
2563 arguments even if the namespace has not been imported.
2573 Here the compiler will search for `foo' in the namespace of 'b'
2574 and find A::foo. GDB now supports this. This construct is commonly
2575 used in the Standard Template Library for operators.
2577 ** Improved User Defined Operator Support
2579 In addition to member operators, GDB now supports lookup of operators
2580 defined in a namespace and imported with a `using' directive, operators
2581 defined in the global scope, operators imported implicitly from an
2582 anonymous namespace, and the ADL operators mentioned in the previous
2584 GDB now also supports proper overload resolution for all the previously
2585 mentioned flavors of operators.
2587 ** static const class members
2589 Printing of static const class members that are initialized in the
2590 class definition has been fixed.
2592 * Windows Thread Information Block access.
2594 On Windows targets, GDB now supports displaying the Windows Thread
2595 Information Block (TIB) structure. This structure is visible either
2596 by using the new command `info w32 thread-information-block' or, by
2597 dereferencing the new convenience variable named `$_tlb', a
2598 thread-specific pointer to the TIB. This feature is also supported
2599 when remote debugging using GDBserver.
2601 * Static tracepoints
2603 Static tracepoints are calls in the user program into a tracing
2604 library. One such library is a port of the LTTng kernel tracer to
2605 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2606 When debugging with GDBserver, GDB now supports combining the GDB
2607 tracepoint machinery with such libraries. For example: the user can
2608 use GDB to probe a static tracepoint marker (a call from the user
2609 program into the tracing library) with the new "strace" command (see
2610 "New commands" below). This creates a "static tracepoint" in the
2611 breakpoint list, that can be manipulated with the same feature set
2612 as fast and regular tracepoints. E.g., collect registers, local and
2613 global variables, collect trace state variables, and define
2614 tracepoint conditions. In addition, the user can collect extra
2615 static tracepoint marker specific data, by collecting the new
2616 $_sdata internal variable. When analyzing the trace buffer, you can
2617 inspect $_sdata like any other variable available to GDB. For more
2618 information, see the "Tracepoints" chapter in GDB user manual. New
2619 remote packets have been defined to support static tracepoints, see
2620 the "New remote packets" section below.
2622 * Better reconstruction of tracepoints after disconnected tracing
2624 GDB will attempt to download the original source form of tracepoint
2625 definitions when starting a trace run, and then will upload these
2626 upon reconnection to the target, resulting in a more accurate
2627 reconstruction of the tracepoints that are in use on the target.
2631 You can now exercise direct control over the ways that GDB can
2632 affect your program. For instance, you can disallow the setting of
2633 breakpoints, so that the program can run continuously (assuming
2634 non-stop mode). In addition, the "observer" variable is available
2635 to switch all of the different controls; in observer mode, GDB
2636 cannot affect the target's behavior at all, which is useful for
2637 tasks like diagnosing live systems in the field.
2639 * The new convenience variable $_thread holds the number of the
2642 * New remote packets
2646 Return the address of the Windows Thread Information Block of a given thread.
2650 In response to several of the tracepoint packets, the target may now
2651 also respond with a number of intermediate `qRelocInsn' request
2652 packets before the final result packet, to have GDB handle
2653 relocating an instruction to execute at a different address. This
2654 is particularly useful for stubs that support fast tracepoints. GDB
2655 reports support for this feature in the qSupported packet.
2659 List static tracepoint markers in the target program.
2663 List static tracepoint markers at a given address in the target
2666 qXfer:statictrace:read
2668 Read the static trace data collected (by a `collect $_sdata'
2669 tracepoint action). The remote stub reports support for this packet
2670 to gdb's qSupported query.
2674 Send the current settings of GDB's permission flags.
2678 Send part of the source (textual) form of a tracepoint definition,
2679 which includes location, conditional, and action list.
2681 * The source command now accepts a -s option to force searching for the
2682 script in the source search path even if the script name specifies
2685 * New features in the GDB remote stub, GDBserver
2687 - GDBserver now support tracepoints (including fast tracepoints, and
2688 static tracepoints). The feature is currently supported by the
2689 i386-linux and amd64-linux builds. See the "Tracepoints support
2690 in gdbserver" section in the manual for more information.
2692 GDBserver JIT compiles the tracepoint's conditional agent
2693 expression bytecode into native code whenever possible for low
2694 overhead dynamic tracepoints conditionals. For such tracepoints,
2695 an expression that examines program state is evaluated when the
2696 tracepoint is reached, in order to determine whether to capture
2697 trace data. If the condition is simple and false, processing the
2698 tracepoint finishes very quickly and no data is gathered.
2700 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2701 for static tracepoints support.
2703 - GDBserver now supports x86_64 Windows 64-bit debugging.
2705 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2706 it understands register description.
2708 * The --batch flag now disables pagination and queries.
2710 * X86 general purpose registers
2712 GDB now supports reading/writing byte, word and double-word x86
2713 general purpose registers directly. This means you can use, say,
2714 $ah or $ax to refer, respectively, to the byte register AH and
2715 16-bit word register AX that are actually portions of the 32-bit
2716 register EAX or 64-bit register RAX.
2718 * The `commands' command now accepts a range of breakpoints to modify.
2719 A plain `commands' following a command that creates multiple
2720 breakpoints affects all the breakpoints set by that command. This
2721 applies to breakpoints set by `rbreak', and also applies when a
2722 single `break' command creates multiple breakpoints (e.g.,
2723 breakpoints on overloaded c++ functions).
2725 * The `rbreak' command now accepts a filename specification as part of
2726 its argument, limiting the functions selected by the regex to those
2727 in the specified file.
2729 * Support for remote debugging Windows and SymbianOS shared libraries
2730 from Unix hosts has been improved. Non Windows GDB builds now can
2731 understand target reported file names that follow MS-DOS based file
2732 system semantics, such as file names that include drive letters and
2733 use the backslash character as directory separator. This makes it
2734 possible to transparently use the "set sysroot" and "set
2735 solib-search-path" on Unix hosts to point as host copies of the
2736 target's shared libraries. See the new command "set
2737 target-file-system-kind" described below, and the "Commands to
2738 specify files" section in the user manual for more information.
2742 eval template, expressions...
2743 Convert the values of one or more expressions under the control
2744 of the string template to a command line, and call it.
2746 set target-file-system-kind unix|dos-based|auto
2747 show target-file-system-kind
2748 Set or show the assumed file system kind for target reported file
2751 save breakpoints <filename>
2752 Save all current breakpoint definitions to a file suitable for use
2753 in a later debugging session. To read the saved breakpoint
2754 definitions, use the `source' command.
2756 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2759 info static-tracepoint-markers
2760 Display information about static tracepoint markers in the target.
2762 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2763 Define a static tracepoint by probing a marker at the given
2764 function, line, address, or marker ID.
2768 Enable and disable observer mode.
2770 set may-write-registers on|off
2771 set may-write-memory on|off
2772 set may-insert-breakpoints on|off
2773 set may-insert-tracepoints on|off
2774 set may-insert-fast-tracepoints on|off
2775 set may-interrupt on|off
2776 Set individual permissions for GDB effects on the target. Note that
2777 some of these settings can have undesirable or surprising
2778 consequences, particularly when changed in the middle of a session.
2779 For instance, disabling the writing of memory can prevent
2780 breakpoints from being inserted, cause single-stepping to fail, or
2781 even crash your program, if you disable after breakpoints have been
2782 inserted. However, GDB should not crash.
2784 set record memory-query on|off
2785 show record memory-query
2786 Control whether to stop the inferior if memory changes caused
2787 by an instruction cannot be recorded.
2792 The disassemble command now supports "start,+length" form of two arguments.
2796 ** GDB now provides a new directory location, called the python directory,
2797 where Python scripts written for GDB can be installed. The location
2798 of that directory is <data-directory>/python, where <data-directory>
2799 is the GDB data directory. For more details, see section `Scripting
2800 GDB using Python' in the manual.
2802 ** The GDB Python API now has access to breakpoints, symbols, symbol
2803 tables, program spaces, inferiors, threads and frame's code blocks.
2804 Additionally, GDB Parameters can now be created from the API, and
2805 manipulated via set/show in the CLI.
2807 ** New functions gdb.target_charset, gdb.target_wide_charset,
2808 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2810 ** New exception gdb.GdbError.
2812 ** Pretty-printers are now also looked up in the current program space.
2814 ** Pretty-printers can now be individually enabled and disabled.
2816 ** GDB now looks for names of Python scripts to auto-load in a
2817 special section named `.debug_gdb_scripts', in addition to looking
2818 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2820 * Tracepoint actions were unified with breakpoint commands. In particular,
2821 there are no longer differences in "info break" output for breakpoints and
2822 tracepoints and the "commands" command can be used for both tracepoints and
2823 regular breakpoints.
2827 ARM Symbian arm*-*-symbianelf*
2829 * D language support.
2830 GDB now supports debugging programs written in the D programming
2833 * GDB now supports the extended ptrace interface for PowerPC which is
2834 available since Linux kernel version 2.6.34. This automatically enables
2835 any hardware breakpoints and additional hardware watchpoints available in
2836 the processor. The old ptrace interface exposes just one hardware
2837 watchpoint and no hardware breakpoints.
2839 * GDB is now able to use the Data Value Compare (DVC) register available on
2840 embedded PowerPC processors to implement in hardware simple watchpoint
2841 conditions of the form:
2843 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2845 This works in native GDB running on Linux kernels with the extended ptrace
2846 interface mentioned above.
2848 *** Changes in GDB 7.1
2852 ** Namespace Support
2854 GDB now supports importing of namespaces in C++. This enables the
2855 user to inspect variables from imported namespaces. Support for
2856 namepace aliasing has also been added. So, if a namespace is
2857 aliased in the current scope (e.g. namepace C=A; ) the user can
2858 print variables using the alias (e.g. (gdb) print C::x).
2862 All known bugs relating to the printing of virtual base class were
2863 fixed. It is now possible to call overloaded static methods using a
2868 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2869 and reinterpret_cast<> are now handled by the C++ expression parser.
2873 Xilinx MicroBlaze microblaze-*-*
2878 Xilinx MicroBlaze microblaze
2881 * Multi-program debugging.
2883 GDB now has support for multi-program (a.k.a. multi-executable or
2884 multi-exec) debugging. This allows for debugging multiple inferiors
2885 simultaneously each running a different program under the same GDB
2886 session. See "Debugging Multiple Inferiors and Programs" in the
2887 manual for more information. This implied some user visible changes
2888 in the multi-inferior support. For example, "info inferiors" now
2889 lists inferiors that are not running yet or that have exited
2890 already. See also "New commands" and "New options" below.
2892 * New tracing features
2894 GDB's tracepoint facility now includes several new features:
2896 ** Trace state variables
2898 GDB tracepoints now include support for trace state variables, which
2899 are variables managed by the target agent during a tracing
2900 experiment. They are useful for tracepoints that trigger each
2901 other, so for instance one tracepoint can count hits in a variable,
2902 and then a second tracepoint has a condition that is true when the
2903 count reaches a particular value. Trace state variables share the
2904 $-syntax of GDB convenience variables, and can appear in both
2905 tracepoint actions and condition expressions. Use the "tvariable"
2906 command to create, and "info tvariables" to view; see "Trace State
2907 Variables" in the manual for more detail.
2911 GDB now includes an option for defining fast tracepoints, which
2912 targets may implement more efficiently, such as by installing a jump
2913 into the target agent rather than a trap instruction. The resulting
2914 speedup can be by two orders of magnitude or more, although the
2915 tradeoff is that some program locations on some target architectures
2916 might not allow fast tracepoint installation, for instance if the
2917 instruction to be replaced is shorter than the jump. To request a
2918 fast tracepoint, use the "ftrace" command, with syntax identical to
2919 the regular trace command.
2921 ** Disconnected tracing
2923 It is now possible to detach GDB from the target while it is running
2924 a trace experiment, then reconnect later to see how the experiment
2925 is going. In addition, a new variable disconnected-tracing lets you
2926 tell the target agent whether to continue running a trace if the
2927 connection is lost unexpectedly.
2931 GDB now has the ability to save the trace buffer into a file, and
2932 then use that file as a target, similarly to you can do with
2933 corefiles. You can select trace frames, print data that was
2934 collected in them, and use tstatus to display the state of the
2935 tracing run at the moment that it was saved. To create a trace
2936 file, use "tsave <filename>", and to use it, do "target tfile
2939 ** Circular trace buffer
2941 You can ask the target agent to handle the trace buffer as a
2942 circular buffer, discarding the oldest trace frames to make room for
2943 newer ones, by setting circular-trace-buffer to on. This feature may
2944 not be available for all target agents.
2949 The disassemble command, when invoked with two arguments, now requires
2950 the arguments to be comma-separated.
2953 The info variables command now displays variable definitions. Files
2954 which only declare a variable are not shown.
2957 The source command is now capable of sourcing Python scripts.
2958 This feature is dependent on the debugger being build with Python
2961 Related to this enhancement is also the introduction of a new command
2962 "set script-extension" (see below).
2964 * New commands (for set/show, see "New options" below)
2966 record save [<FILENAME>]
2967 Save a file (in core file format) containing the process record
2968 execution log for replay debugging at a later time.
2970 record restore <FILENAME>
2971 Restore the process record execution log that was saved at an
2972 earlier time, for replay debugging.
2974 add-inferior [-copies <N>] [-exec <FILENAME>]
2977 clone-inferior [-copies <N>] [ID]
2978 Make a new inferior ready to execute the same program another
2979 inferior has loaded.
2984 maint info program-spaces
2985 List the program spaces loaded into GDB.
2987 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2988 show remote interrupt-sequence
2989 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2990 as the sequence to the remote target in order to interrupt the execution.
2991 Ctrl-C is a default. Some system prefers BREAK which is high level of
2992 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2993 Magic SysRq g. It is BREAK signal and character 'g'.
2995 set remote interrupt-on-connect [on | off]
2996 show remote interrupt-on-connect
2997 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2998 remote target when gdb connects to it. This is needed when you debug
3001 set remotebreak [on | off]
3003 Deprecated. Use "set/show remote interrupt-sequence" instead.
3005 tvariable $NAME [ = EXP ]
3006 Create or modify a trace state variable.
3009 List trace state variables and their values.
3011 delete tvariable $NAME ...
3012 Delete one or more trace state variables.
3015 Evaluate the given expressions without collecting anything into the
3016 trace buffer. (Valid in tracepoint actions only.)
3018 ftrace FN / FILE:LINE / *ADDR
3019 Define a fast tracepoint at the given function, line, or address.
3021 * New expression syntax
3023 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3024 GDB now parses 0b101010 identically with 42.
3028 set follow-exec-mode new|same
3029 show follow-exec-mode
3030 Control whether GDB reuses the same inferior across an exec call or
3031 creates a new one. This is useful to be able to restart the old
3032 executable after the inferior having done an exec call.
3034 set default-collect EXPR, ...
3035 show default-collect
3036 Define a list of expressions to be collected at each tracepoint.
3037 This is a useful way to ensure essential items are not overlooked,
3038 such as registers or a critical global variable.
3040 set disconnected-tracing
3041 show disconnected-tracing
3042 If set to 1, the target is instructed to continue tracing if it
3043 loses its connection to GDB. If 0, the target is to stop tracing
3046 set circular-trace-buffer
3047 show circular-trace-buffer
3048 If set to on, the target is instructed to use a circular trace buffer
3049 and discard the oldest trace frames instead of stopping the trace due
3050 to a full trace buffer. If set to off, the trace stops when the buffer
3051 fills up. Some targets may not support this.
3053 set script-extension off|soft|strict
3054 show script-extension
3055 If set to "off", the debugger does not perform any script language
3056 recognition, and all sourced files are assumed to be GDB scripts.
3057 If set to "soft" (the default), files are sourced according to
3058 filename extension, falling back to GDB scripts if the first
3060 If set to "strict", files are sourced according to filename extension.
3062 set ada trust-PAD-over-XVS on|off
3063 show ada trust-PAD-over-XVS
3064 If off, activate a workaround against a bug in the debugging information
3065 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3066 the GCC sources for more information about the GNAT encoding and
3067 PAD types in particular). It is always safe to set this option to
3068 off, but this introduces a slight performance penalty. The default
3071 * Python API Improvements
3073 ** GDB provides the new class gdb.LazyString. This is useful in
3074 some pretty-printing cases. The new method gdb.Value.lazy_string
3075 provides a simple way to create objects of this type.
3077 ** The fields returned by gdb.Type.fields now have an
3078 `is_base_class' attribute.
3080 ** The new method gdb.Type.range returns the range of an array type.
3082 ** The new method gdb.parse_and_eval can be used to parse and
3083 evaluate an expression.
3085 * New remote packets
3088 Define a trace state variable.
3091 Get the current value of a trace state variable.
3094 Set desired tracing behavior upon disconnection.
3097 Set the trace buffer to be linear or circular.
3100 Get data about the tracepoints currently in use.
3104 Process record now works correctly with hardware watchpoints.
3106 Multiple bug fixes have been made to the mips-irix port, making it
3107 much more reliable. In particular:
3108 - Debugging threaded applications is now possible again. Previously,
3109 GDB would hang while starting the program, or while waiting for
3110 the program to stop at a breakpoint.
3111 - Attaching to a running process no longer hangs.
3112 - An error occurring while loading a core file has been fixed.
3113 - Changing the value of the PC register now works again. This fixes
3114 problems observed when using the "jump" command, or when calling
3115 a function from GDB, or even when assigning a new value to $pc.
3116 - With the "finish" and "return" commands, the return value for functions
3117 returning a small array is now correctly printed.
3118 - It is now possible to break on shared library code which gets executed
3119 during a shared library init phase (code executed while executing
3120 their .init section). Previously, the breakpoint would have no effect.
3121 - GDB is now able to backtrace through the signal handler for
3122 non-threaded programs.
3124 PIE (Position Independent Executable) programs debugging is now supported.
3125 This includes debugging execution of PIC (Position Independent Code) shared
3126 libraries although for that, it should be possible to run such libraries as an
3129 *** Changes in GDB 7.0
3131 * GDB now has an interface for JIT compilation. Applications that
3132 dynamically generate code can create symbol files in memory and register
3133 them with GDB. For users, the feature should work transparently, and
3134 for JIT developers, the interface is documented in the GDB manual in the
3135 "JIT Compilation Interface" chapter.
3137 * Tracepoints may now be conditional. The syntax is as for
3138 breakpoints; either an "if" clause appended to the "trace" command,
3139 or the "condition" command is available. GDB sends the condition to
3140 the target for evaluation using the same bytecode format as is used
3141 for tracepoint actions.
3143 * The disassemble command now supports: an optional /r modifier, print the
3144 raw instructions in hex as well as in symbolic form, and an optional /m
3145 modifier to print mixed source+assembly.
3147 * Process record and replay
3149 In a architecture environment that supports ``process record and
3150 replay'', ``process record and replay'' target can record a log of
3151 the process execution, and replay it with both forward and reverse
3154 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3155 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3156 set execution-direction {forward|reverse}, for targets that support
3159 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3160 feature is available with a native GDB running on kernel version
3163 * GDB now has support for multi-byte and wide character sets on the
3164 target. Strings whose character type is wchar_t, char16_t, or
3165 char32_t are now correctly printed. GDB supports wide- and unicode-
3166 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3167 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3168 `printf'. This feature requires iconv to work properly; if your
3169 system does not have a working iconv, GDB can use GNU libiconv. See
3170 the installation instructions for more information.
3172 * GDB now supports automatic retrieval of shared library files from
3173 remote targets. To use this feature, specify a system root that begins
3174 with the `remote:' prefix, either via the `set sysroot' command or via
3175 the `--with-sysroot' configure-time option.
3177 * "info sharedlibrary" now takes an optional regex of libraries to show,
3178 and it now reports if a shared library has no debugging information.
3180 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3181 now complete on file names.
3183 * When completing in expressions, gdb will attempt to limit
3184 completions to allowable structure or union fields, where appropriate.
3185 For instance, consider:
3187 # struct example { int f1; double f2; };
3188 # struct example variable;
3191 If the user types TAB at the end of this command line, the available
3192 completions will be "f1" and "f2".
3194 * Inlined functions are now supported. They show up in backtraces, and
3195 the "step", "next", and "finish" commands handle them automatically.
3197 * GDB now supports the token-splicing (##) and stringification (#)
3198 operators when expanding macros. It also supports variable-arity
3201 * GDB now supports inspecting extra signal information, exported by
3202 the new $_siginfo convenience variable. The feature is currently
3203 implemented on linux ARM, i386 and amd64.
3205 * GDB can now display the VFP floating point registers and NEON vector
3206 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3207 can provide these registers (requires Linux 2.6.30 or later). Remote
3208 and simulator targets may also provide them.
3210 * New remote packets
3213 Search memory for a sequence of bytes.
3216 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3217 operation over reliable transport links. Use of this packet is
3218 controlled by the `set remote noack-packet' command.
3221 Kill the process with the specified process ID. Use this in preference
3222 to `k' when multiprocess protocol extensions are supported.
3225 Obtains additional operating system information
3229 Read or write additional signal information.
3231 * Removed remote protocol undocumented extension
3233 An undocumented extension to the remote protocol's `S' stop reply
3234 packet that permited the stub to pass a process id was removed.
3235 Remote servers should use the `T' stop reply packet instead.
3237 * GDB now supports multiple function calling conventions according to the
3238 DWARF-2 DW_AT_calling_convention function attribute.
3240 * The SH target utilizes the aforementioned change to distinguish between gcc
3241 and Renesas calling convention. It also adds the new CLI commands
3242 `set/show sh calling-convention'.
3244 * GDB can now read compressed debug sections, as produced by GNU gold
3245 with the --compress-debug-sections=zlib flag.
3247 * 64-bit core files are now supported on AIX.
3249 * Thread switching is now supported on Tru64.
3251 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3252 which will be allocated using malloc later in program execution.
3254 * The qXfer:libraries:read remote procotol packet now allows passing a
3255 list of section offsets.
3257 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3258 conditions handling signals delivered during attach or thread creation
3259 have also been fixed.
3261 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3262 From the user's standpoint, all unqualified instances of True and False
3263 are treated as the standard definitions, regardless of context.
3265 * GDB now parses C++ symbol and type names more flexibly. For
3268 template<typename T> class C { };
3271 GDB will now correctly handle all of:
3273 ptype C<char const *>
3274 ptype C<char const*>
3275 ptype C<const char *>
3276 ptype C<const char*>
3278 * New features in the GDB remote stub, gdbserver
3280 - The "--wrapper" command-line argument tells gdbserver to use a
3281 wrapper program to launch programs for debugging.
3283 - On PowerPC and S/390 targets, it is now possible to use a single
3284 gdbserver executable to debug both 32-bit and 64-bit programs.
3285 (This requires gdbserver itself to be built as a 64-bit executable.)
3287 - gdbserver uses the new noack protocol mode for TCP connections to
3288 reduce communications latency, if also supported and enabled in GDB.
3290 - Support for the sparc64-linux-gnu target is now included in
3293 - The amd64-linux build of gdbserver now supports debugging both
3294 32-bit and 64-bit programs.
3296 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3297 now support hardware watchpoints, and will use them automatically
3302 GDB now has support for scripting using Python. Whether this is
3303 available is determined at configure time.
3305 New GDB commands can now be written in Python.
3307 * Ada tasking support
3309 Ada tasks can now be inspected in GDB. The following commands have
3313 Print the list of Ada tasks.
3315 Print detailed information about task number N.
3317 Print the task number of the current task.
3319 Switch the context of debugging to task number N.
3321 * Support for user-defined prefixed commands. The "define" command can
3322 add new commands to existing prefixes, e.g. "target".
3324 * Multi-inferior, multi-process debugging.
3326 GDB now has generalized support for multi-inferior debugging. See
3327 "Debugging Multiple Inferiors" in the manual for more information.
3328 Although availability still depends on target support, the command
3329 set is more uniform now. The GNU/Linux specific multi-forks support
3330 has been migrated to this new framework. This implied some user
3331 visible changes; see "New commands" and also "Removed commands"
3334 * Target descriptions can now describe the target OS ABI. See the
3335 "Target Description Format" section in the user manual for more
3338 * Target descriptions can now describe "compatible" architectures
3339 to indicate that the target can execute applications for a different
3340 architecture in addition to those for the main target architecture.
3341 See the "Target Description Format" section in the user manual for
3344 * Multi-architecture debugging.
3346 GDB now includes general supports for debugging applications on
3347 hybrid systems that use more than one single processor architecture
3348 at the same time. Each such hybrid architecture still requires
3349 specific support to be added. The only hybrid architecture supported
3350 in this version of GDB is the Cell Broadband Engine.
3352 * GDB now supports integrated debugging of Cell/B.E. applications that
3353 use both the PPU and SPU architectures. To enable support for hybrid
3354 Cell/B.E. debugging, you need to configure GDB to support both the
3355 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3356 --enable-targets configure option.
3358 * Non-stop mode debugging.
3360 For some targets, GDB now supports an optional mode of operation in
3361 which you can examine stopped threads while other threads continue
3362 to execute freely. This is referred to as non-stop mode, with the
3363 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3364 section in the user manual for more information.
3366 To be able to support remote non-stop debugging, a remote stub needs
3367 to implement the non-stop mode remote protocol extensions, as
3368 described in the "Remote Non-Stop" section of the user manual. The
3369 GDB remote stub, gdbserver, has been adjusted to support these
3370 extensions on linux targets.
3372 * New commands (for set/show, see "New options" below)
3374 catch syscall [NAME(S) | NUMBER(S)]
3375 Catch system calls. Arguments, which should be names of system
3376 calls or their numbers, mean catch only those syscalls. Without
3377 arguments, every syscall will be caught. When the inferior issues
3378 any of the specified syscalls, GDB will stop and announce the system
3379 call, both when it is called and when its call returns. This
3380 feature is currently available with a native GDB running on the
3381 Linux Kernel, under the following architectures: x86, x86_64,
3382 PowerPC and PowerPC64.
3384 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3386 Search memory for a sequence of bytes.
3388 maint set python print-stack
3389 maint show python print-stack
3390 Show a stack trace when an error is encountered in a Python script.
3393 Invoke CODE by passing it to the Python interpreter.
3398 These allow macros to be defined, undefined, and listed
3402 Show operating system information about processes.
3405 List the inferiors currently under GDB's control.
3408 Switch focus to inferior number NUM.
3411 Detach from inferior number NUM.
3414 Kill inferior number NUM.
3418 set spu stop-on-load
3419 show spu stop-on-load
3420 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3422 set spu auto-flush-cache
3423 show spu auto-flush-cache
3424 Control whether to automatically flush the software-managed cache
3425 during Cell/B.E. debugging.
3427 set sh calling-convention
3428 show sh calling-convention
3429 Control the calling convention used when calling SH target functions.
3432 show debug timestamp
3433 Control display of timestamps with GDB debugging output.
3435 set disassemble-next-line
3436 show disassemble-next-line
3437 Control display of disassembled source lines or instructions when
3440 set remote noack-packet
3441 show remote noack-packet
3442 Set/show the use of remote protocol QStartNoAckMode packet. See above
3443 under "New remote packets."
3445 set remote query-attached-packet
3446 show remote query-attached-packet
3447 Control use of remote protocol `qAttached' (query-attached) packet.
3449 set remote read-siginfo-object
3450 show remote read-siginfo-object
3451 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3454 set remote write-siginfo-object
3455 show remote write-siginfo-object
3456 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3459 set remote reverse-continue
3460 show remote reverse-continue
3461 Control use of remote protocol 'bc' (reverse-continue) packet.
3463 set remote reverse-step
3464 show remote reverse-step
3465 Control use of remote protocol 'bs' (reverse-step) packet.
3467 set displaced-stepping
3468 show displaced-stepping
3469 Control displaced stepping mode. Displaced stepping is a way to
3470 single-step over breakpoints without removing them from the debuggee.
3471 Also known as "out-of-line single-stepping".
3474 show debug displaced
3475 Control display of debugging info for displaced stepping.
3477 maint set internal-error
3478 maint show internal-error
3479 Control what GDB does when an internal error is detected.
3481 maint set internal-warning
3482 maint show internal-warning
3483 Control what GDB does when an internal warning is detected.
3488 Use a wrapper program to launch programs for debugging.
3490 set multiple-symbols (all|ask|cancel)
3491 show multiple-symbols
3492 The value of this variable can be changed to adjust the debugger behavior
3493 when an expression or a breakpoint location contains an ambiguous symbol
3494 name (an overloaded function name, for instance).
3496 set breakpoint always-inserted
3497 show breakpoint always-inserted
3498 Keep breakpoints always inserted in the target, as opposed to inserting
3499 them when resuming the target, and removing them when the target stops.
3500 This option can improve debugger performance on slow remote targets.
3502 set arm fallback-mode (arm|thumb|auto)
3503 show arm fallback-mode
3504 set arm force-mode (arm|thumb|auto)
3506 These commands control how ARM GDB determines whether instructions
3507 are ARM or Thumb. The default for both settings is auto, which uses
3508 the current CPSR value for instructions without symbols; previous
3509 versions of GDB behaved as if "set arm fallback-mode arm".
3511 set disable-randomization
3512 show disable-randomization
3513 Standalone programs run with the virtual address space randomization enabled
3514 by default on some platforms. This option keeps the addresses stable across
3515 multiple debugging sessions.
3519 Control whether other threads are stopped or not when some thread hits
3524 Requests that asynchronous execution is enabled in the target, if available.
3525 In this case, it's possible to resume target in the background, and interact
3526 with GDB while the target is running. "show target-async" displays the
3527 current state of asynchronous execution of the target.
3529 set target-wide-charset
3530 show target-wide-charset
3531 The target-wide-charset is the name of the character set that GDB
3532 uses when printing characters whose type is wchar_t.
3534 set tcp auto-retry (on|off)
3536 set tcp connect-timeout
3537 show tcp connect-timeout
3538 These commands allow GDB to retry failed TCP connections to a remote stub
3539 with a specified timeout period; this is useful if the stub is launched
3540 in parallel with GDB but may not be ready to accept connections immediately.
3542 set libthread-db-search-path
3543 show libthread-db-search-path
3544 Control list of directories which GDB will search for appropriate
3547 set schedule-multiple (on|off)
3548 show schedule-multiple
3549 Allow GDB to resume all threads of all processes or only threads of
3550 the current process.
3554 Use more aggressive caching for accesses to the stack. This improves
3555 performance of remote debugging (particularly backtraces) without
3556 affecting correctness.
3558 set interactive-mode (on|off|auto)
3559 show interactive-mode
3560 Control whether GDB runs in interactive mode (on) or not (off).
3561 When in interactive mode, GDB waits for the user to answer all
3562 queries. Otherwise, GDB does not wait and assumes the default
3563 answer. When set to auto (the default), GDB determines which
3564 mode to use based on the stdin settings.
3569 For program forks, this is replaced by the new more generic `info
3570 inferiors' command. To list checkpoints, you can still use the
3571 `info checkpoints' command, which was an alias for the `info forks'
3575 Replaced by the new `inferior' command. To switch between
3576 checkpoints, you can still use the `restart' command, which was an
3577 alias for the `fork' command.
3580 This is removed, since some targets don't have a notion of
3581 processes. To switch between processes, you can still use the
3582 `inferior' command using GDB's own inferior number.
3585 For program forks, this is replaced by the new more generic `kill
3586 inferior' command. To delete a checkpoint, you can still use the
3587 `delete checkpoint' command, which was an alias for the `delete
3591 For program forks, this is replaced by the new more generic `detach
3592 inferior' command. To detach a checkpoint, you can still use the
3593 `detach checkpoint' command, which was an alias for the `detach
3596 * New native configurations
3598 x86/x86_64 Darwin i[34567]86-*-darwin*
3600 x86_64 MinGW x86_64-*-mingw*
3604 Lattice Mico32 lm32-*
3605 x86 DICOS i[34567]86-*-dicos*
3606 x86_64 DICOS x86_64-*-dicos*
3609 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3610 (mingw32ce) debugging.
3616 These commands were actually not implemented on any target.
3618 *** Changes in GDB 6.8
3620 * New native configurations
3622 NetBSD/hppa hppa*-*netbsd*
3623 Xtensa GNU/Linux xtensa*-*-linux*
3627 NetBSD/hppa hppa*-*-netbsd*
3628 Xtensa GNU/Lunux xtensa*-*-linux*
3630 * Change in command line behavior -- corefiles vs. process ids.
3632 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3633 attaching to process NUMBER fails, GDB no longer attempts to open a
3634 core file named NUMBER. Attaching to a program using the -c option
3635 is no longer supported. Instead, use the '-p' or '--pid' options.
3637 * GDB can now be built as a native debugger for debugging Windows x86
3638 (mingw32) Portable Executable (PE) programs.
3640 * Pending breakpoints no longer change their number when their address
3643 * GDB now supports breakpoints with multiple locations,
3644 including breakpoints on C++ constructors, inside C++ templates,
3645 and in inlined functions.
3647 * GDB's ability to debug optimized code has been improved. GDB more
3648 accurately identifies function bodies and lexical blocks that occupy
3649 more than one contiguous range of addresses.
3651 * Target descriptions can now describe registers for PowerPC.
3653 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3654 registers on PowerPC targets.
3656 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3657 targets even when the libthread_db library is not available.
3659 * The GDB remote stub, gdbserver, now supports the new file transfer
3660 commands (remote put, remote get, and remote delete).
3662 * The GDB remote stub, gdbserver, now supports run and attach in
3663 extended-remote mode.
3665 * hppa*64*-*-hpux11* target broken
3666 The debugger is unable to start a program and fails with the following
3667 error: "Error trying to get information about dynamic linker".
3668 The gdb-6.7 release is also affected.
3670 * GDB now supports the --enable-targets= configure option to allow
3671 building a single GDB executable that supports multiple remote
3672 target architectures.
3674 * GDB now supports debugging C and C++ programs which use the
3675 Decimal Floating Point extension. In addition, the PowerPC target
3676 now has a set of pseudo-registers to inspect decimal float values
3677 stored in two consecutive float registers.
3679 * The -break-insert MI command can optionally create pending
3682 * Improved support for debugging Ada
3683 Many improvements to the Ada language support have been made. These
3685 - Better support for Ada2005 interface types
3686 - Improved handling of arrays and slices in general
3687 - Better support for Taft-amendment types
3688 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3690 - Improved command completion in Ada
3693 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3698 set print frame-arguments (all|scalars|none)
3699 show print frame-arguments
3700 The value of this variable can be changed to control which argument
3701 values should be printed by the debugger when displaying a frame.
3706 Transfer files to and from a remote target, and delete remote files.
3713 Transfer files to and from a remote target, and delete remote files.
3715 * New remote packets
3722 Open, close, read, write, and delete files on the remote system.
3725 Attach to an existing process on the remote system, in extended-remote
3729 Run a new process on the remote system, in extended-remote mode.
3731 *** Changes in GDB 6.7
3733 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3734 bfd, libiberty and opcodes, as revealed by static analysis donated by
3735 Coverity, Inc. (http://scan.coverity.com).
3737 * When looking up multiply-defined global symbols, GDB will now prefer the
3738 symbol definition in the current shared library if it was built using the
3739 -Bsymbolic linker option.
3741 * When the Text User Interface (TUI) is not configured, GDB will now
3742 recognize the -tui command-line option and print a message that the TUI
3745 * The GDB remote stub, gdbserver, now has lower overhead for high
3746 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3748 * GDB for MIPS targets now autodetects whether a remote target provides
3749 32-bit or 64-bit register values.
3751 * Support for C++ member pointers has been improved.
3753 * GDB now understands XML target descriptions, which specify the
3754 target's overall architecture. GDB can read a description from
3755 a local file or over the remote serial protocol.
3757 * Vectors of single-byte data use a new integer type which is not
3758 automatically displayed as character or string data.
3760 * The /s format now works with the print command. It displays
3761 arrays of single-byte integers and pointers to single-byte integers
3764 * Target descriptions can now describe target-specific registers,
3765 for architectures which have implemented the support (currently
3766 only ARM, M68K, and MIPS).
3768 * GDB and the GDB remote stub, gdbserver, now support the XScale
3771 * The GDB remote stub, gdbserver, has been updated to support
3772 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3773 has been rewritten to use the standard GDB remote protocol.
3775 * GDB can now step into C++ functions which are called through thunks.
3777 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3779 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3780 layout. It also supports a TextSeg= and DataSeg= response when only
3781 segment base addresses (rather than offsets) are available.
3783 * The /i format now outputs any trailing branch delay slot instructions
3784 immediately following the last instruction within the count specified.
3786 * The GDB remote protocol "T" stop reply packet now supports a
3787 "library" response. Combined with the new "qXfer:libraries:read"
3788 packet, this response allows GDB to debug shared libraries on targets
3789 where the operating system manages the list of loaded libraries (e.g.
3790 Windows and SymbianOS).
3792 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3793 (DLLs) on Windows and Windows CE targets.
3795 * GDB now supports a faster verification that a .debug file matches its binary
3796 according to its build-id signature, if the signature is present.
3802 Enable or disable hardware flow control (RTS/CTS) on the serial port
3803 when debugging using remote targets.
3805 set mem inaccessible-by-default
3806 show mem inaccessible-by-default
3807 If the target supplies a memory map, for instance via the remote
3808 protocol's "qXfer:memory-map:read" packet, setting this variable
3809 prevents GDB from accessing memory outside the memory map. This
3810 is useful for targets with memory mapped registers or which react
3811 badly to accesses of unmapped address space.
3813 set breakpoint auto-hw
3814 show breakpoint auto-hw
3815 If the target supplies a memory map, for instance via the remote
3816 protocol's "qXfer:memory-map:read" packet, setting this variable
3817 lets GDB use hardware breakpoints automatically for memory regions
3818 where it can not use software breakpoints. This covers both the
3819 "break" command and internal breakpoints used for other commands
3820 including "next" and "finish".
3823 catch exception unhandled
3824 Stop the program execution when Ada exceptions are raised.
3827 Stop the program execution when an Ada assertion failed.
3831 Set an alternate system root for target files. This is a more
3832 general version of "set solib-absolute-prefix", which is now
3833 an alias to "set sysroot".
3836 Provide extended SPU facility status information. This set of
3837 commands is available only when debugging the Cell/B.E. SPU
3840 * New native configurations
3842 OpenBSD/sh sh*-*openbsd*
3845 unset tdesc filename
3847 Use the specified local file as an XML target description, and do
3848 not query the target for its built-in description.
3852 OpenBSD/sh sh*-*-openbsd*
3853 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3854 Toshiba Media Processor mep-elf
3856 * New remote packets
3859 Ignore the specified signals; pass them directly to the debugged program
3860 without stopping other threads or reporting them to GDB.
3862 qXfer:features:read:
3863 Read an XML target description from the target, which describes its
3868 Read or write contents of an spufs file on the target system. These
3869 packets are available only on the Cell/B.E. SPU architecture.
3871 qXfer:libraries:read:
3872 Report the loaded shared libraries. Combined with new "T" packet
3873 response, this packet allows GDB to debug shared libraries on
3874 targets where the operating system manages the list of loaded
3875 libraries (e.g. Windows and SymbianOS).
3879 Support for these obsolete configurations has been removed.
3887 i[34567]86-*-lynxos*
3888 i[34567]86-*-netware*
3889 i[34567]86-*-sco3.2v5*
3890 i[34567]86-*-sco3.2v4*
3892 i[34567]86-*-sysv4.2*
3895 i[34567]86-*-unixware2*
3896 i[34567]86-*-unixware*
3905 * Other removed features
3912 Various m68k-only ROM monitors.
3919 Various Renesas ROM monitors and debugging interfaces for SH and
3924 Support for a Macraigor serial interface to on-chip debugging.
3925 GDB does not directly support the newer parallel or USB
3930 A debug information format. The predecessor to DWARF 2 and
3931 DWARF 3, which are still supported.
3933 Support for the HP aCC compiler on HP-UX/PA-RISC
3935 SOM-encapsulated symbolic debugging information, automatic
3936 invocation of pxdb, and the aCC custom C++ ABI. This does not
3937 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3938 with aCC can still be debugged on an assembly level.
3940 MIPS ".pdr" sections
3942 A MIPS-specific format used to describe stack frame layout
3943 in debugging information.
3947 GDB could work with an older version of Guile to debug
3948 the interpreter and Scheme programs running in it.
3950 set mips stack-arg-size
3951 set mips saved-gpreg-size
3953 Use "set mips abi" to control parameter passing for MIPS.
3955 *** Changes in GDB 6.6
3960 Cell Broadband Engine SPU spu-elf
3962 * GDB can now be configured as a cross-debugger targeting native Windows
3963 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3964 running on a Windows system over TCP/IP to debug Windows programs.
3966 * The GDB remote stub, gdbserver, has been updated to support Windows and
3967 Cygwin debugging. Both single-threaded and multi-threaded programs are
3970 * The "set trust-readonly-sections" command works again. This command was
3971 broken in GDB 6.3, 6.4, and 6.5.
3973 * The "load" command now supports writing to flash memory, if the remote
3974 stub provides the required support.
3976 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3977 longer requires symbolic debug information (e.g. DWARF-2).
3982 unset substitute-path
3983 show substitute-path
3984 Manage a list of substitution rules that GDB uses to rewrite the name
3985 of the directories where the sources are located. This can be useful
3986 for instance when the sources were moved to a different location
3987 between compilation and debugging.
3991 Print each CLI command as it is executed. Each command is prefixed with
3992 a number of `+' symbols representing the nesting depth.
3993 The source command now has a `-v' option to enable the same feature.
3997 The ARM Demon monitor support (RDP protocol, "target rdp").
3999 Kernel Object Display, an embedded debugging feature which only worked with
4000 an obsolete version of Cisco IOS.
4002 The 'set download-write-size' and 'show download-write-size' commands.
4004 * New remote packets
4007 Tell a stub about GDB client features, and request remote target features.
4008 The first feature implemented is PacketSize, which allows the target to
4009 specify the size of packets it can handle - to minimize the number of
4010 packets required and improve performance when connected to a remote
4014 Fetch an OS auxilliary vector from the remote stub. This packet is a
4015 more efficient replacement for qPart:auxv:read.
4017 qXfer:memory-map:read:
4018 Fetch a memory map from the remote stub, including information about
4019 RAM, ROM, and flash memory devices.
4024 Erase and program a flash memory device.
4026 * Removed remote packets
4029 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4030 used it, and only gdbserver implemented it.
4032 *** Changes in GDB 6.5
4036 Renesas M32C/M16C m32c-elf
4038 Morpho Technologies ms1 ms1-elf
4042 init-if-undefined Initialize a convenience variable, but
4043 only if it doesn't already have a value.
4045 The following commands are presently only implemented for native GNU/Linux:
4047 checkpoint Save a snapshot of the program state.
4049 restart <n> Return the program state to a
4050 previously saved state.
4052 info checkpoints List currently saved checkpoints.
4054 delete-checkpoint <n> Delete a previously saved checkpoint.
4056 set|show detach-on-fork Tell gdb whether to detach from a newly
4057 forked process, or to keep debugging it.
4059 info forks List forks of the user program that
4060 are available to be debugged.
4062 fork <n> Switch to debugging one of several
4063 forks of the user program that are
4064 available to be debugged.
4066 delete-fork <n> Delete a fork from the list of forks
4067 that are available to be debugged (and
4068 kill the forked process).
4070 detach-fork <n> Delete a fork from the list of forks
4071 that are available to be debugged (and
4072 allow the process to continue).
4076 Morpho Technologies ms2 ms1-elf
4078 * Improved Windows host support
4080 GDB now builds as a cross debugger hosted on i686-mingw32, including
4081 native console support, and remote communications using either
4082 network sockets or serial ports.
4084 * Improved Modula-2 language support
4086 GDB can now print most types in the Modula-2 syntax. This includes:
4087 basic types, set types, record types, enumerated types, range types,
4088 pointer types and ARRAY types. Procedure var parameters are correctly
4089 printed and hexadecimal addresses and character constants are also
4090 written in the Modula-2 syntax. Best results can be obtained by using
4091 GNU Modula-2 together with the -gdwarf-2 command line option.
4095 The ARM rdi-share module.
4097 The Netware NLM debug server.
4099 *** Changes in GDB 6.4
4101 * New native configurations
4103 OpenBSD/arm arm*-*-openbsd*
4104 OpenBSD/mips64 mips64-*-openbsd*
4108 Morpho Technologies ms1 ms1-elf
4110 * New command line options
4112 --batch-silent As for --batch, but totally silent.
4113 --return-child-result The debugger will exist with the same value
4114 the child (debugged) program exited with.
4115 --eval-command COMMAND, -ex COMMAND
4116 Execute a single GDB CLI command. This may be
4117 specified multiple times and in conjunction
4118 with the --command (-x) option.
4120 * Deprecated commands removed
4122 The following commands, that were deprecated in 2000, have been
4126 set|show arm disassembly-flavor set|show arm disassembler
4127 othernames set arm disassembler
4128 set|show remotedebug set|show debug remote
4129 set|show archdebug set|show debug arch
4130 set|show eventdebug set|show debug event
4133 * New BSD user-level threads support
4135 It is now possible to debug programs using the user-level threads
4136 library on OpenBSD and FreeBSD. Currently supported (target)
4139 FreeBSD/amd64 x86_64-*-freebsd*
4140 FreeBSD/i386 i386-*-freebsd*
4141 OpenBSD/i386 i386-*-openbsd*
4143 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4144 are not yet supported.
4146 * New support for Matsushita MN10300 w/sim added
4147 (Work in progress). mn10300-elf.
4149 * REMOVED configurations and files
4151 VxWorks and the XDR protocol *-*-vxworks
4152 Motorola MCORE mcore-*-*
4153 National Semiconductor NS32000 ns32k-*-*
4155 * New "set print array-indexes" command
4157 After turning this setting "on", GDB prints the index of each element
4158 when displaying arrays. The default is "off" to preserve the previous
4161 * VAX floating point support
4163 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4165 * User-defined command support
4167 In addition to using $arg0..$arg9 for argument passing, it is now possible
4168 to use $argc to determine now many arguments have been passed. See the
4169 section on user-defined commands in the user manual for more information.
4171 *** Changes in GDB 6.3:
4173 * New command line option
4175 GDB now accepts -l followed by a number to set the timeout for remote
4178 * GDB works with GCC -feliminate-dwarf2-dups
4180 GDB now supports a more compact representation of DWARF-2 debug
4181 information using DW_FORM_ref_addr references. These are produced
4182 by GCC with the option -feliminate-dwarf2-dups and also by some
4183 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4184 to use -feliminate-dwarf2-dups.
4186 * Internationalization
4188 When supported by the host system, GDB will be built with
4189 internationalization (libintl). The task of marking up the sources is
4190 continued, we're looking forward to our first translation.
4194 Initial support for debugging programs compiled with the GNAT
4195 implementation of the Ada programming language has been integrated
4196 into GDB. In this release, support is limited to expression evaluation.
4198 * New native configurations
4200 GNU/Linux/m32r m32r-*-linux-gnu
4204 GDB's remote protocol now includes support for the 'p' packet. This
4205 packet is used to fetch individual registers from a remote inferior.
4207 * END-OF-LIFE registers[] compatibility module
4209 GDB's internal register infrastructure has been completely rewritten.
4210 The new infrastructure making possible the implementation of key new
4211 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4214 GDB 6.3 will be the last release to include the the registers[]
4215 compatibility module that allowed out-of-date configurations to
4216 continue to work. This change directly impacts the following
4226 powerpc bdm protocol
4228 Unless there is activity to revive these configurations, they will be
4229 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4231 * OBSOLETE configurations and files
4233 Configurations that have been declared obsolete in this release have
4234 been commented out. Unless there is activity to revive these
4235 configurations, the next release of GDB will have their sources
4236 permanently REMOVED.
4245 *** Changes in GDB 6.2.1:
4247 * MIPS `break main; run' gave an heuristic-fence-post warning
4249 When attempting to run even a simple program, a warning about
4250 heuristic-fence-post being hit would be reported. This problem has
4253 * MIPS IRIX 'long double' crashed GDB
4255 When examining a long double variable, GDB would get a segmentation
4256 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4257 IRIX long double values).
4261 A bug in the VAX stack code was causing problems with the "next"
4262 command. This problem has been fixed.
4264 *** Changes in GDB 6.2:
4266 * Fix for ``many threads''
4268 On GNU/Linux systems that use the NPTL threads library, a program
4269 rapidly creating and deleting threads would confuse GDB leading to the
4272 ptrace: No such process.
4273 thread_db_get_info: cannot get thread info: generic error
4275 This problem has been fixed.
4277 * "-async" and "-noasync" options removed.
4279 Support for the broken "-noasync" option has been removed (it caused
4282 * New ``start'' command.
4284 This command runs the program until the begining of the main procedure.
4286 * New BSD Kernel Data Access Library (libkvm) interface
4288 Using ``target kvm'' it is now possible to debug kernel core dumps and
4289 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4290 platforms. Currently supported (native-only) configurations are:
4292 FreeBSD/amd64 x86_64-*-freebsd*
4293 FreeBSD/i386 i?86-*-freebsd*
4294 NetBSD/i386 i?86-*-netbsd*
4295 NetBSD/m68k m68*-*-netbsd*
4296 NetBSD/sparc sparc-*-netbsd*
4297 OpenBSD/amd64 x86_64-*-openbsd*
4298 OpenBSD/i386 i?86-*-openbsd*
4299 OpenBSD/m68k m68*-openbsd*
4300 OpenBSD/sparc sparc-*-openbsd*
4302 * Signal trampoline code overhauled
4304 Many generic problems with GDB's signal handling code have been fixed.
4305 These include: backtraces through non-contiguous stacks; recognition
4306 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4307 call; backtrace through a signal trampoline; step into and out of
4308 signal handlers; and single-stepping in the signal trampoline.
4310 Please note that kernel bugs are a limiting factor here. These
4311 features have been shown to work on an s390 GNU/Linux system that
4312 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4314 * Cygwin support for DWARF 2 added.
4316 * New native configurations
4318 GNU/Linux/hppa hppa*-*-linux*
4319 OpenBSD/hppa hppa*-*-openbsd*
4320 OpenBSD/m68k m68*-*-openbsd*
4321 OpenBSD/m88k m88*-*-openbsd*
4322 OpenBSD/powerpc powerpc-*-openbsd*
4323 NetBSD/vax vax-*-netbsd*
4324 OpenBSD/vax vax-*-openbsd*
4326 * END-OF-LIFE frame compatibility module
4328 GDB's internal frame infrastructure has been completely rewritten.
4329 The new infrastructure making it possible to support key new features
4330 including DWARF 2 Call Frame Information. To aid in the task of
4331 migrating old configurations to this new infrastructure, a
4332 compatibility module, that allowed old configurations to continue to
4333 work, was also included.
4335 GDB 6.2 will be the last release to include this frame compatibility
4336 module. This change directly impacts the following configurations:
4346 Unless there is activity to revive these configurations, they will be
4347 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4349 * REMOVED configurations and files
4351 Sun 3, running SunOS 3 m68*-*-sunos3*
4352 Sun 3, running SunOS 4 m68*-*-sunos4*
4353 Sun 2, running SunOS 3 m68000-*-sunos3*
4354 Sun 2, running SunOS 4 m68000-*-sunos4*
4355 Motorola 680x0 running LynxOS m68*-*-lynxos*
4356 AT&T 3b1/Unix pc m68*-att-*
4357 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4358 decstation mips-dec-* mips-little-*
4359 riscos mips-*-riscos* mips-*-sysv*
4360 sonymips mips-sony-*
4361 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4363 *** Changes in GDB 6.1.1:
4365 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4367 The TUI (Text-mode User Interface) is now built as part of a default
4368 GDB configuration. It is enabled by either selecting the TUI with the
4369 command line option "-i=tui" or by running the separate "gdbtui"
4370 program. For more information on the TUI, see the manual "Debugging
4373 * Pending breakpoint support (also included in GDB 6.1)
4375 Support has been added to allow you to specify breakpoints in shared
4376 libraries that have not yet been loaded. If a breakpoint location
4377 cannot be found, and the "breakpoint pending" option is set to auto,
4378 GDB queries you if you wish to make the breakpoint pending on a future
4379 shared-library load. If and when GDB resolves the breakpoint symbol,
4380 the pending breakpoint is removed as one or more regular breakpoints
4383 Pending breakpoints are very useful for GCJ Java debugging.
4385 * Fixed ISO-C build problems
4387 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4388 non ISO-C code that stopped them being built using a more strict ISO-C
4389 compiler (e.g., IBM's C compiler).
4391 * Fixed build problem on IRIX 5
4393 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4394 wasn't able to compile compile on an IRIX 5 system.
4396 * Added execute permission to gdb/gdbserver/configure
4398 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4399 permission. This bug would cause configure to fail on a number of
4400 systems (Solaris, IRIX). Ref: server/519.
4402 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4404 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4405 has been updated to use constant array sizes.
4407 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4409 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4410 its generated DWARF Call Frame Info. This encoding was causing GDB to
4411 panic, that panic has been fixed. Ref: gdb/1628.
4413 * Fixed a problem when examining parameters in shared library code.
4415 When examining parameters in optimized shared library code generated
4416 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4417 not available''. GDB now correctly displays the variable's value.
4419 *** Changes in GDB 6.1:
4421 * Removed --with-mmalloc
4423 Support for the mmalloc memory manager has been removed, as it
4424 conflicted with the internal gdb byte cache.
4426 * Changes in AMD64 configurations
4428 The AMD64 target now includes the %cs and %ss registers. As a result
4429 the AMD64 remote protocol has changed; this affects the floating-point
4430 and SSE registers. If you rely on those registers for your debugging,
4431 you should upgrade gdbserver on the remote side.
4433 * Revised SPARC target
4435 The SPARC target has been completely revised, incorporating the
4436 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4437 support for LynxOS and SunOS 4 has been dropped. Calling functions
4438 from within GDB on operating systems with a non-executable stack
4439 (Solaris, OpenBSD) now works.
4443 GDB has a new C++ demangler which does a better job on the mangled
4444 names generated by current versions of g++. It also runs faster, so
4445 with this and other changes gdb should now start faster on large C++
4448 * DWARF 2 Location Expressions
4450 GDB support for location expressions has been extended to support function
4451 arguments and frame bases. Older versions of GDB could crash when they
4454 * C++ nested types and namespaces
4456 GDB's support for nested types and namespaces in C++ has been
4457 improved, especially if you use the DWARF 2 debugging format. (This
4458 is the default for recent versions of GCC on most platforms.)
4459 Specifically, if you have a class "Inner" defined within a class or
4460 namespace "Outer", then GDB realizes that the class's name is
4461 "Outer::Inner", not simply "Inner". This should greatly reduce the
4462 frequency of complaints about not finding RTTI symbols. In addition,
4463 if you are stopped at inside of a function defined within a namespace,
4464 GDB modifies its name lookup accordingly.
4466 * New native configurations
4468 NetBSD/amd64 x86_64-*-netbsd*
4469 OpenBSD/amd64 x86_64-*-openbsd*
4470 OpenBSD/alpha alpha*-*-openbsd*
4471 OpenBSD/sparc sparc-*-openbsd*
4472 OpenBSD/sparc64 sparc64-*-openbsd*
4474 * New debugging protocols
4476 M32R with SDI protocol m32r-*-elf*
4478 * "set prompt-escape-char" command deleted.
4480 The command "set prompt-escape-char" has been deleted. This command,
4481 and its very obscure effet on GDB's prompt, was never documented,
4482 tested, nor mentioned in the NEWS file.
4484 * OBSOLETE configurations and files
4486 Configurations that have been declared obsolete in this release have
4487 been commented out. Unless there is activity to revive these
4488 configurations, the next release of GDB will have their sources
4489 permanently REMOVED.
4491 Sun 3, running SunOS 3 m68*-*-sunos3*
4492 Sun 3, running SunOS 4 m68*-*-sunos4*
4493 Sun 2, running SunOS 3 m68000-*-sunos3*
4494 Sun 2, running SunOS 4 m68000-*-sunos4*
4495 Motorola 680x0 running LynxOS m68*-*-lynxos*
4496 AT&T 3b1/Unix pc m68*-att-*
4497 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4498 decstation mips-dec-* mips-little-*
4499 riscos mips-*-riscos* mips-*-sysv*
4500 sonymips mips-sony-*
4501 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4503 * REMOVED configurations and files
4505 SGI Irix-4.x mips-sgi-irix4 or iris4
4506 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4507 Z8000 simulator z8k-zilog-none or z8ksim
4508 Matsushita MN10200 w/simulator mn10200-*-*
4509 H8/500 simulator h8500-hitachi-hms or h8500hms
4510 HP/PA running BSD hppa*-*-bsd*
4511 HP/PA running OSF/1 hppa*-*-osf*
4512 HP/PA Pro target hppa*-*-pro*
4513 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4514 386BSD i[3456]86-*-bsd*
4515 Sequent family i[3456]86-sequent-sysv4*
4516 i[3456]86-sequent-sysv*
4517 i[3456]86-sequent-bsd*
4518 SPARC running LynxOS sparc-*-lynxos*
4519 SPARC running SunOS 4 sparc-*-sunos4*
4520 Tsqware Sparclet sparclet-*-*
4521 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4523 *** Changes in GDB 6.0:
4527 Support for debugging the Objective-C programming language has been
4528 integrated into GDB.
4530 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4532 DWARF 2's Call Frame Information makes available compiler generated
4533 information that more exactly describes the program's run-time stack.
4534 By using this information, GDB is able to provide more robust stack
4537 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4538 have been updated to use a new backtrace mechanism which includes
4539 DWARF 2 CFI support.
4543 GDB's remote protocol has been extended to include support for hosted
4544 file I/O (where the remote target uses GDB's file system). See GDB's
4545 remote protocol documentation for details.
4547 * All targets using the new architecture framework.
4549 All of GDB's targets have been updated to use the new internal
4550 architecture framework. The way is now open for future GDB releases
4551 to include cross-architecture native debugging support (i386 on amd64,
4554 * GNU/Linux's Thread Local Storage (TLS)
4556 GDB now includes support for for the GNU/Linux implementation of
4557 per-thread variables.
4559 * GNU/Linux's Native POSIX Thread Library (NPTL)
4561 GDB's thread code has been updated to work with either the new
4562 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4564 * Separate debug info.
4566 GDB, in conjunction with BINUTILS, now supports a mechanism for
4567 automatically loading debug information from a separate file. Instead
4568 of shipping full debug and non-debug versions of system libraries,
4569 system integrators can now instead ship just the stripped libraries
4570 and optional debug files.
4572 * DWARF 2 Location Expressions
4574 DWARF 2 Location Expressions allow the compiler to more completely
4575 describe the location of variables (even in optimized code) to the
4578 GDB now includes preliminary support for location expressions (support
4579 for DW_OP_piece is still missing).
4583 A number of long standing bugs that caused GDB to die while starting a
4584 Java application have been fixed. GDB's Java support is now
4585 considered "useable".
4587 * GNU/Linux support for fork, vfork, and exec.
4589 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4590 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4593 * GDB supports logging output to a file
4595 There are two new commands, "set logging" and "show logging", which can be
4596 used to capture GDB's output to a file.
4598 * The meaning of "detach" has changed for gdbserver
4600 The "detach" command will now resume the application, as documented. To
4601 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4604 * d10v, m68hc11 `regs' command deprecated
4606 The `info registers' command has been updated so that it displays the
4607 registers using a format identical to the old `regs' command.
4611 A new command, "maint set profile on/off", has been added. This command can
4612 be used to enable or disable profiling while running GDB, to profile a
4613 session or a set of commands. In addition there is a new configure switch,
4614 "--enable-profiling", which will cause GDB to be compiled with profiling
4615 data, for more informative profiling results.
4617 * Default MI syntax changed to "mi2".
4619 The default MI (machine interface) syntax, enabled by the command line
4620 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4621 "mi1", can be enabled by specifying the option "-i=mi1".
4623 Support for the original "mi0" syntax (included in GDB 5.0) has been
4626 Fix for gdb/192: removed extraneous space when displaying frame level.
4627 Fix for gdb/672: update changelist is now output in mi list format.
4628 Fix for gdb/702: a -var-assign that updates the value now shows up
4629 in a subsequent -var-update.
4631 * New native configurations.
4633 FreeBSD/amd64 x86_64-*-freebsd*
4635 * Multi-arched targets.
4637 HP/PA HPUX11 hppa*-*-hpux*
4638 Renesas M32R/D w/simulator m32r-*-elf*
4640 * OBSOLETE configurations and files
4642 Configurations that have been declared obsolete in this release have
4643 been commented out. Unless there is activity to revive these
4644 configurations, the next release of GDB will have their sources
4645 permanently REMOVED.
4647 Z8000 simulator z8k-zilog-none or z8ksim
4648 Matsushita MN10200 w/simulator mn10200-*-*
4649 H8/500 simulator h8500-hitachi-hms or h8500hms
4650 HP/PA running BSD hppa*-*-bsd*
4651 HP/PA running OSF/1 hppa*-*-osf*
4652 HP/PA Pro target hppa*-*-pro*
4653 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4654 Sequent family i[3456]86-sequent-sysv4*
4655 i[3456]86-sequent-sysv*
4656 i[3456]86-sequent-bsd*
4657 Tsqware Sparclet sparclet-*-*
4658 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4660 * REMOVED configurations and files
4663 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4664 IBM AIX PS/2 i[3456]86-*-aix
4665 i386 running Mach 3.0 i[3456]86-*-mach3*
4666 i386 running Mach i[3456]86-*-mach*
4667 i386 running OSF/1 i[3456]86-*osf1mk*
4668 HP/Apollo 68k Family m68*-apollo*-sysv*,
4670 m68*-hp-bsd*, m68*-hp-hpux*
4671 Argonaut Risc Chip (ARC) arc-*-*
4672 Mitsubishi D30V d30v-*-*
4673 Fujitsu FR30 fr30-*-elf*
4674 OS/9000 i[34]86-*-os9k
4675 I960 with MON960 i960-*-coff
4677 * MIPS $fp behavior changed
4679 The convenience variable $fp, for the MIPS, now consistently returns
4680 the address of the current frame's base. Previously, depending on the
4681 context, $fp could refer to either $sp or the current frame's base
4682 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4683 The GNU Source-Level Debugger''.
4685 *** Changes in GDB 5.3:
4687 * GNU/Linux shared library multi-threaded performance improved.
4689 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4690 `/proc', in preference to `ptrace' for memory reads. This may result
4691 in an improvement in the start-up time of multi-threaded, shared
4692 library applications when run under GDB. One GDB user writes: ``loads
4693 shared libs like mad''.
4695 * ``gdbserver'' now supports multi-threaded applications on some targets
4697 Support for debugging multi-threaded applications which use
4698 the GNU/Linux LinuxThreads package has been added for
4699 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4700 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4702 * GDB now supports C/C++ preprocessor macros.
4704 GDB now expands preprocessor macro invocations in C/C++ expressions,
4705 and provides various commands for showing macro definitions and how
4708 The new command `macro expand EXPRESSION' expands any macro
4709 invocations in expression, and shows the result.
4711 The new command `show macro MACRO-NAME' shows the definition of the
4712 macro named MACRO-NAME, and where it was defined.
4714 Most compilers don't include information about macros in the debugging
4715 information by default. In GCC 3.1, for example, you need to compile
4716 your program with the options `-gdwarf-2 -g3'. If the macro
4717 information is present in the executable, GDB will read it.
4719 * Multi-arched targets.
4721 DEC Alpha (partial) alpha*-*-*
4722 DEC VAX (partial) vax-*-*
4724 National Semiconductor NS32000 (partial) ns32k-*-*
4725 Motorola 68000 (partial) m68k-*-*
4726 Motorola MCORE mcore-*-*
4730 Fujitsu FRV architecture added by Red Hat frv*-*-*
4733 * New native configurations
4735 Alpha NetBSD alpha*-*-netbsd*
4736 SH NetBSD sh*-*-netbsdelf*
4737 MIPS NetBSD mips*-*-netbsd*
4738 UltraSPARC NetBSD sparc64-*-netbsd*
4740 * OBSOLETE configurations and files
4742 Configurations that have been declared obsolete in this release have
4743 been commented out. Unless there is activity to revive these
4744 configurations, the next release of GDB will have their sources
4745 permanently REMOVED.
4747 Mitsubishi D30V d30v-*-*
4748 OS/9000 i[34]86-*-os9k
4749 IBM AIX PS/2 i[3456]86-*-aix
4750 Fujitsu FR30 fr30-*-elf*
4751 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4752 Argonaut Risc Chip (ARC) arc-*-*
4753 i386 running Mach 3.0 i[3456]86-*-mach3*
4754 i386 running Mach i[3456]86-*-mach*
4755 i386 running OSF/1 i[3456]86-*osf1mk*
4756 HP/Apollo 68k Family m68*-apollo*-sysv*,
4758 m68*-hp-bsd*, m68*-hp-hpux*
4759 I960 with MON960 i960-*-coff
4761 * OBSOLETE languages
4763 CHILL, a Pascal like language used by telecommunications companies.
4765 * REMOVED configurations and files
4767 AMD 29k family via UDI a29k-amd-udi, udi29k
4768 A29K VxWorks a29k-*-vxworks
4769 AMD 29000 embedded, using EBMON a29k-none-none
4770 AMD 29000 embedded with COFF a29k-none-coff
4771 AMD 29000 embedded with a.out a29k-none-aout
4773 testsuite/gdb.hp/gdb.threads-hp/ directory
4775 * New command "set max-user-call-depth <nnn>"
4777 This command allows the user to limit the call depth of user-defined
4778 commands. The default is 1024.
4780 * Changes in FreeBSD/i386 native debugging.
4782 Support for the "generate-core-file" has been added.
4784 * New commands "dump", "append", and "restore".
4786 These commands allow data to be copied from target memory
4787 to a bfd-format or binary file (dump and append), and back
4788 from a file into memory (restore).
4790 * Improved "next/step" support on multi-processor Alpha Tru64.
4792 The previous single-step mechanism could cause unpredictable problems,
4793 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4794 of a software single-step mechanism prevents this.
4796 *** Changes in GDB 5.2.1:
4804 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4805 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4806 Fix, by Joel Brobecker imported from mainline.
4808 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4809 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4810 Fix, by Fred Fish, imported from mainline.
4812 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4813 Surprisingly enough, it works now.
4814 By Michal Ludvig, imported from mainline.
4816 i386 hardware watchpoint support:
4817 avoid misses on second run for some targets.
4818 By Pierre Muller, imported from mainline.
4820 *** Changes in GDB 5.2:
4822 * New command "set trust-readonly-sections on[off]".
4824 This command is a hint that tells gdb that read-only sections
4825 really are read-only (ie. that their contents will not change).
4826 In this mode, gdb will go to the object file rather than the
4827 target to read memory from read-only sections (such as ".text").
4828 This can be a significant performance improvement on some
4829 (notably embedded) targets.
4831 * New command "generate-core-file" (or "gcore").
4833 This new gdb command allows the user to drop a core file of the child
4834 process state at any time. So far it's been implemented only for
4835 GNU/Linux and Solaris, but should be relatively easily ported to other
4836 hosts. Argument is core file name (defaults to core.<pid>).
4838 * New command line option
4840 GDB now accepts --pid or -p followed by a process id.
4842 * Change in command line behavior -- corefiles vs. process ids.
4844 There is a subtle behavior in the way in which GDB handles
4845 command line arguments. The first non-flag argument is always
4846 a program to debug, but the second non-flag argument may either
4847 be a corefile or a process id. Previously, GDB would attempt to
4848 open the second argument as a corefile, and if that failed, would
4849 issue a superfluous error message and then attempt to attach it as
4850 a process. Now, if the second argument begins with a non-digit,
4851 it will be treated as a corefile. If it begins with a digit,
4852 GDB will attempt to attach it as a process, and if no such process
4853 is found, will then attempt to open it as a corefile.
4855 * Changes in ARM configurations.
4857 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4858 configuration is fully multi-arch.
4860 * New native configurations
4862 ARM NetBSD arm*-*-netbsd*
4863 x86 OpenBSD i[3456]86-*-openbsd*
4864 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4865 Sparc64 running FreeBSD sparc64-*-freebsd*
4869 Sanyo XStormy16 xstormy16-elf
4871 * OBSOLETE configurations and files
4873 Configurations that have been declared obsolete in this release have
4874 been commented out. Unless there is activity to revive these
4875 configurations, the next release of GDB will have their sources
4876 permanently REMOVED.
4878 AMD 29k family via UDI a29k-amd-udi, udi29k
4879 A29K VxWorks a29k-*-vxworks
4880 AMD 29000 embedded, using EBMON a29k-none-none
4881 AMD 29000 embedded with COFF a29k-none-coff
4882 AMD 29000 embedded with a.out a29k-none-aout
4884 testsuite/gdb.hp/gdb.threads-hp/ directory
4886 * REMOVED configurations and files
4888 TI TMS320C80 tic80-*-*
4890 PowerPC Solaris powerpcle-*-solaris*
4891 PowerPC Windows NT powerpcle-*-cygwin32
4892 PowerPC Netware powerpc-*-netware*
4893 Harris/CXUX m88k m88*-harris-cxux*
4894 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4895 ns32k-utek-sysv* ns32k-utek-*
4896 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4897 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4898 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4899 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4900 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4902 * Changes to command line processing
4904 The new `--args' feature can be used to specify command-line arguments
4905 for the inferior from gdb's command line.
4907 * Changes to key bindings
4909 There is a new `operate-and-get-next' function bound to `C-o'.
4911 *** Changes in GDB 5.1.1
4913 Fix compile problem on DJGPP.
4915 Fix a problem with floating-point registers on the i386 being
4918 Fix to stop GDB crashing on .debug_str debug info.
4920 Numerous documentation fixes.
4922 Numerous testsuite fixes.
4924 *** Changes in GDB 5.1:
4926 * New native configurations
4928 Alpha FreeBSD alpha*-*-freebsd*
4929 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4930 MIPS GNU/Linux mips*-*-linux*
4931 MIPS SGI Irix 6.x mips*-sgi-irix6*
4932 ia64 AIX ia64-*-aix*
4933 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4937 Motorola 68HC11 and 68HC12 m68hc11-elf
4939 UltraSparc running GNU/Linux sparc64-*-linux*
4941 * OBSOLETE configurations and files
4943 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4944 Harris/CXUX m88k m88*-harris-cxux*
4945 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4946 ns32k-utek-sysv* ns32k-utek-*
4947 TI TMS320C80 tic80-*-*
4949 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4950 PowerPC Solaris powerpcle-*-solaris*
4951 PowerPC Windows NT powerpcle-*-cygwin32
4952 PowerPC Netware powerpc-*-netware*
4953 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4954 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4955 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4956 Apple Macintosh (MPW) host N/A
4958 stuff.c (Program to stuff files into a specially prepared space in kdb)
4959 kdb-start.c (Main loop for the standalone kernel debugger)
4961 Configurations that have been declared obsolete in this release have
4962 been commented out. Unless there is activity to revive these
4963 configurations, the next release of GDB will have their sources
4964 permanently REMOVED.
4966 * REMOVED configurations and files
4968 Altos 3068 m68*-altos-*
4969 Convex c1-*-*, c2-*-*
4971 ARM RISCix arm-*-* (as host)
4975 * GDB has been converted to ISO C.
4977 GDB's source code has been converted to ISO C. In particular, the
4978 sources are fully protoized, and rely on standard headers being
4983 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4985 * The MI enabled by default.
4987 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4988 revised and enabled by default. Packages which use GDB as a debugging
4989 engine behind a UI or another front end are encouraged to switch to
4990 using the GDB/MI interface, instead of the old annotations interface
4991 which is now deprecated.
4993 * Support for debugging Pascal programs.
4995 GDB now includes support for debugging Pascal programs. The following
4996 main features are supported:
4998 - Pascal-specific data types such as sets;
5000 - automatic recognition of Pascal sources based on file-name
5003 - Pascal-style display of data types, variables, and functions;
5005 - a Pascal expression parser.
5007 However, some important features are not yet supported.
5009 - Pascal string operations are not supported at all;
5011 - there are some problems with boolean types;
5013 - Pascal type hexadecimal constants are not supported
5014 because they conflict with the internal variables format;
5016 - support for Pascal objects and classes is not full yet;
5018 - unlike Pascal, GDB is case-sensitive for symbol names.
5020 * Changes in completion.
5022 Commands such as `shell', `run' and `set args', which pass arguments
5023 to inferior programs, now complete on file names, similar to what
5024 users expect at the shell prompt.
5026 Commands which accept locations, such as `disassemble', `print',
5027 `breakpoint', `until', etc. now complete on filenames as well as
5028 program symbols. Thus, if you type "break foob TAB", and the source
5029 files linked into the programs include `foobar.c', that file name will
5030 be one of the candidates for completion. However, file names are not
5031 considered for completion after you typed a colon that delimits a file
5032 name from a name of a function in that file, as in "break foo.c:bar".
5034 `set demangle-style' completes on available demangling styles.
5036 * New platform-independent commands:
5038 It is now possible to define a post-hook for a command as well as a
5039 hook that runs before the command. For more details, see the
5040 documentation of `hookpost' in the GDB manual.
5042 * Changes in GNU/Linux native debugging.
5044 Support for debugging multi-threaded programs has been completely
5045 revised for all platforms except m68k and sparc. You can now debug as
5046 many threads as your system allows you to have.
5048 Attach/detach is supported for multi-threaded programs.
5050 Support for SSE registers was added for x86. This doesn't work for
5051 multi-threaded programs though.
5053 * Changes in MIPS configurations.
5055 Multi-arch support is enabled for all MIPS configurations.
5057 GDB can now be built as native debugger on SGI Irix 6.x systems for
5058 debugging n32 executables. (Debugging 64-bit executables is not yet
5061 * Unified support for hardware watchpoints in all x86 configurations.
5063 Most (if not all) native x86 configurations support hardware-assisted
5064 breakpoints and watchpoints in a unified manner. This support
5065 implements debug register sharing between watchpoints, which allows to
5066 put a virtually infinite number of watchpoints on the same address,
5067 and also supports watching regions up to 16 bytes with several debug
5070 The new maintenance command `maintenance show-debug-regs' toggles
5071 debugging print-outs in functions that insert, remove, and test
5072 watchpoints and hardware breakpoints.
5074 * Changes in the DJGPP native configuration.
5076 New command ``info dos sysinfo'' displays assorted information about
5077 the CPU, OS, memory, and DPMI server.
5079 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5080 display information about segment descriptors stored in GDT, LDT, and
5083 New commands ``info dos pde'' and ``info dos pte'' display entries
5084 from Page Directory and Page Tables (for now works with CWSDPMI only).
5085 New command ``info dos address-pte'' displays the Page Table entry for
5086 a given linear address.
5088 GDB can now pass command lines longer than 126 characters to the
5089 program being debugged (requires an update to the libdbg.a library
5090 which is part of the DJGPP development kit).
5092 DWARF2 debug info is now supported.
5094 It is now possible to `step' and `next' through calls to `longjmp'.
5096 * Changes in documentation.
5098 All GDB documentation was converted to GFDL, the GNU Free
5099 Documentation License.
5101 Tracepoints-related commands are now fully documented in the GDB
5104 TUI, the Text-mode User Interface, is now documented in the manual.
5106 Tracepoints-related commands are now fully documented in the GDB
5109 The "GDB Internals" manual now has an index. It also includes
5110 documentation of `ui_out' functions, GDB coding standards, x86
5111 hardware watchpoints, and memory region attributes.
5113 * GDB's version number moved to ``version.in''
5115 The Makefile variable VERSION has been replaced by the file
5116 ``version.in''. People creating GDB distributions should update the
5117 contents of this file.
5121 GUD support is now a standard part of the EMACS distribution.
5123 *** Changes in GDB 5.0:
5125 * Improved support for debugging FP programs on x86 targets
5127 Unified and much-improved support for debugging floating-point
5128 programs on all x86 targets. In particular, ``info float'' now
5129 displays the FP registers in the same format on all x86 targets, with
5130 greater level of detail.
5132 * Improvements and bugfixes in hardware-assisted watchpoints
5134 It is now possible to watch array elements, struct members, and
5135 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5136 on x86 targets no longer erroneously trigger when the address is
5139 * Improvements in the native DJGPP version of GDB
5141 The distribution now includes all the scripts and auxiliary files
5142 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5143 machines ``out of the box''.
5145 The DJGPP version can now debug programs that use signals. It is
5146 possible to catch signals that happened in the debuggee, deliver
5147 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5148 would kill the program being debugged.) Programs that hook hardware
5149 interrupts (keyboard, timer, etc.) can also be debugged.
5151 It is now possible to debug DJGPP programs that redirect their
5152 standard handles or switch them to raw (as opposed to cooked) mode, or
5153 even close them. The command ``run < foo > bar'' works as expected,
5154 and ``info terminal'' reports useful information about the debuggee's
5155 terminal, including raw/cooked mode, redirection, etc.
5157 The DJGPP version now uses termios functions for console I/O, which
5158 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5161 DOS-style file names with drive letters are now fully supported by
5164 It is now possible to debug DJGPP programs that switch their working
5165 directory. It is also possible to rerun the debuggee any number of
5166 times without restarting GDB; thus, you can use the same setup,
5167 breakpoints, etc. for many debugging sessions.
5169 * New native configurations
5171 ARM GNU/Linux arm*-*-linux*
5172 PowerPC GNU/Linux powerpc-*-linux*
5176 Motorola MCore mcore-*-*
5177 x86 VxWorks i[3456]86-*-vxworks*
5178 PowerPC VxWorks powerpc-*-vxworks*
5179 TI TMS320C80 tic80-*-*
5181 * OBSOLETE configurations
5183 Altos 3068 m68*-altos-*
5184 Convex c1-*-*, c2-*-*
5186 ARM RISCix arm-*-* (as host)
5189 Configurations that have been declared obsolete will be commented out,
5190 but the code will be left in place. If there is no activity to revive
5191 these configurations before the next release of GDB, the sources will
5192 be permanently REMOVED.
5194 * Gould support removed
5196 Support for the Gould PowerNode and NP1 has been removed.
5198 * New features for SVR4
5200 On SVR4 native platforms (such as Solaris), if you attach to a process
5201 without first loading a symbol file, GDB will now attempt to locate and
5202 load symbols from the running process's executable file.
5204 * Many C++ enhancements
5206 C++ support has been greatly improved. Overload resolution now works properly
5207 in almost all cases. RTTI support is on the way.
5209 * Remote targets can connect to a sub-program
5211 A popen(3) style serial-device has been added. This device starts a
5212 sub-process (such as a stand-alone simulator) and then communicates
5213 with that. The sub-program to run is specified using the syntax
5214 ``|<program> <args>'' vis:
5216 (gdb) set remotedebug 1
5217 (gdb) target extended-remote |mn10300-elf-sim program-args
5219 * MIPS 64 remote protocol
5221 A long standing bug in the mips64 remote protocol where by GDB
5222 expected certain 32 bit registers (ex SR) to be transfered as 32
5223 instead of 64 bits has been fixed.
5225 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5226 added to provide backward compatibility with older versions of GDB.
5228 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5230 The command ``set remotebinarydownload'' command has been replaced by
5231 ``set remote X-packet''. Other commands in ``set remote'' family
5232 include ``set remote P-packet''.
5234 * Breakpoint commands accept ranges.
5236 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5237 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5238 ``tracepoint passcount'' also accepts a range of tracepoints.
5240 * ``apropos'' command added.
5242 The ``apropos'' command searches through command names and
5243 documentation strings, printing out matches, making it much easier to
5244 try to find a command that does what you are looking for.
5248 A new machine oriented interface (MI) has been added to GDB. This
5249 interface is designed for debug environments running GDB as a separate
5250 process. This is part of the long term libGDB project. See the
5251 "GDB/MI" chapter of the GDB manual for further information. It can be
5252 enabled by configuring with:
5254 .../configure --enable-gdbmi
5256 *** Changes in GDB-4.18:
5258 * New native configurations
5260 HP-UX 10.20 hppa*-*-hpux10.20
5261 HP-UX 11.x hppa*-*-hpux11.0*
5262 M68K GNU/Linux m68*-*-linux*
5266 Fujitsu FR30 fr30-*-elf*
5267 Intel StrongARM strongarm-*-*
5268 Mitsubishi D30V d30v-*-*
5270 * OBSOLETE configurations
5272 Gould PowerNode, NP1 np1-*-*, pn-*-*
5274 Configurations that have been declared obsolete will be commented out,
5275 but the code will be left in place. If there is no activity to revive
5276 these configurations before the next release of GDB, the sources will
5277 be permanently REMOVED.
5281 As a compatibility experiment, GDB's source files buildsym.h and
5282 buildsym.c have been converted to pure standard C, no longer
5283 containing any K&R compatibility code. We believe that all systems in
5284 use today either come with a standard C compiler, or have a GCC port
5285 available. If this is not true, please report the affected
5286 configuration to bug-gdb@gnu.org immediately. See the README file for
5287 information about getting a standard C compiler if you don't have one
5292 GDB now uses readline 2.2.
5294 * set extension-language
5296 You can now control the mapping between filename extensions and source
5297 languages by using the `set extension-language' command. For instance,
5298 you can ask GDB to treat .c files as C++ by saying
5299 set extension-language .c c++
5300 The command `info extensions' lists all of the recognized extensions
5301 and their associated languages.
5303 * Setting processor type for PowerPC and RS/6000
5305 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5306 you can use the `set processor' command to specify what variant of the
5307 PowerPC family you are debugging. The command
5311 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5312 following PowerPC and RS6000 variants:
5314 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5315 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5317 403GC IBM PowerPC 403GC
5318 505 Motorola PowerPC 505
5319 860 Motorola PowerPC 860 or 850
5320 601 Motorola PowerPC 601
5321 602 Motorola PowerPC 602
5322 603 Motorola/IBM PowerPC 603 or 603e
5323 604 Motorola PowerPC 604 or 604e
5324 750 Motorola/IBM PowerPC 750 or 750
5326 At the moment, this command just tells GDB what to name the
5327 special-purpose processor registers. Since almost all the affected
5328 registers are inaccessible to user-level programs, this command is
5329 only useful for remote debugging in its present form.
5333 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5334 more extensive support for HP-UX. Added features include shared
5335 library support, kernel threads and hardware watchpoints for 11.00,
5336 support for HP's ANSI C and C++ compilers, and a compatibility mode
5337 for xdb and dbx commands.
5341 HP's donation includes the new concept of catchpoints, which is a
5342 generalization of the old catch command. On HP-UX, it is now possible
5343 to catch exec, fork, and vfork, as well as library loading.
5345 This means that the existing catch command has changed; its first
5346 argument now specifies the type of catch to be set up. See the
5347 output of "help catch" for a list of catchpoint types.
5349 * Debugging across forks
5351 On HP-UX, you can choose which process to debug when a fork() happens
5356 HP has donated a curses-based terminal user interface (TUI). To get
5357 it, build with --enable-tui. Although this can be enabled for any
5358 configuration, at present it only works for native HP debugging.
5360 * GDB remote protocol additions
5362 A new protocol packet 'X' that writes binary data is now available.
5363 Default behavior is to try 'X', then drop back to 'M' if the stub
5364 fails to respond. The settable variable `remotebinarydownload'
5365 allows explicit control over the use of 'X'.
5367 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5368 full 64-bit address. The command
5370 set remoteaddresssize 32
5372 can be used to revert to the old behaviour. For existing remote stubs
5373 the change should not be noticed, as the additional address information
5376 In order to assist in debugging stubs, you may use the maintenance
5377 command `packet' to send any text string to the stub. For instance,
5379 maint packet heythere
5381 sends the packet "$heythere#<checksum>". Note that it is very easy to
5382 disrupt a debugging session by sending the wrong packet at the wrong
5385 The compare-sections command allows you to compare section data on the
5386 target to what is in the executable file without uploading or
5387 downloading, by comparing CRC checksums.
5389 * Tracing can collect general expressions
5391 You may now collect general expressions at tracepoints. This requires
5392 further additions to the target-side stub; see tracepoint.c and
5393 doc/agentexpr.texi for further details.
5395 * mask-address variable for Mips
5397 For Mips targets, you may control the zeroing of the upper 32 bits of
5398 a 64-bit address by entering `set mask-address on'. This is mainly
5399 of interest to users of embedded R4xxx and R5xxx processors.
5401 * Higher serial baud rates
5403 GDB's serial code now allows you to specify baud rates 57600, 115200,
5404 230400, and 460800 baud. (Note that your host system may not be able
5405 to achieve all of these rates.)
5409 The i960 configuration now includes an initial implementation of a
5410 builtin simulator, contributed by Jim Wilson.
5413 *** Changes in GDB-4.17:
5415 * New native configurations
5417 Alpha GNU/Linux alpha*-*-linux*
5418 Unixware 2.x i[3456]86-unixware2*
5419 Irix 6.x mips*-sgi-irix6*
5420 PowerPC GNU/Linux powerpc-*-linux*
5421 PowerPC Solaris powerpcle-*-solaris*
5422 Sparc GNU/Linux sparc-*-linux*
5423 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5427 Argonaut Risc Chip (ARC) arc-*-*
5428 Hitachi H8/300S h8300*-*-*
5429 Matsushita MN10200 w/simulator mn10200-*-*
5430 Matsushita MN10300 w/simulator mn10300-*-*
5431 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5432 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5433 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5434 Mitsubishi D10V w/simulator d10v-*-*
5435 Mitsubishi M32R/D w/simulator m32r-*-elf*
5436 Tsqware Sparclet sparclet-*-*
5437 NEC V850 w/simulator v850-*-*
5439 * New debugging protocols
5441 ARM with RDI protocol arm*-*-*
5442 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5443 DDB and LSI variants of PMON protocol mips*-*-*
5444 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5445 PowerPC with SDS protocol powerpc{,le}-*-eabi
5446 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5450 All configurations can now understand and use the DWARF 2 debugging
5451 format. The choice is automatic, if the symbol file contains DWARF 2
5456 GDB now includes basic Java language support. This support is
5457 only useful with Java compilers that produce native machine code.
5459 * solib-absolute-prefix and solib-search-path
5461 For SunOS and SVR4 shared libraries, you may now set the prefix for
5462 loading absolute shared library symbol files, and the search path for
5463 locating non-absolute shared library symbol files.
5465 * Live range splitting
5467 GDB can now effectively debug code for which GCC has performed live
5468 range splitting as part of its optimization. See gdb/doc/LRS for
5469 more details on the expected format of the stabs information.
5473 GDB's support for the GNU Hurd, including thread debugging, has been
5474 updated to work with current versions of the Hurd.
5478 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5479 instruction set. ARM GDB automatically detects when Thumb
5480 instructions are in use, and adjusts disassembly and backtracing
5485 GDB's MIPS target configurations now handle the MIP16 16-bit
5490 GDB now includes support for overlays; if an executable has been
5491 linked such that multiple sections are based at the same address, GDB
5492 will decide which section to use for symbolic info. You can choose to
5493 control the decision manually, using overlay commands, or implement
5494 additional target-side support and use "overlay load-target" to bring
5495 in the overlay mapping. Do "help overlay" for more detail.
5499 The command "info symbol <address>" displays information about
5500 the symbol at the specified address.
5504 The standard remote protocol now includes an extension that allows
5505 asynchronous collection and display of trace data. This requires
5506 extensive support in the target-side debugging stub. Tracing mode
5507 includes a new interaction mode in GDB and new commands: see the
5508 file tracepoint.c for more details.
5512 Configurations for embedded MIPS now include a simulator contributed
5513 by Cygnus Solutions. The simulator supports the instruction sets
5514 of most MIPS variants.
5518 Sparc configurations may now include the ERC32 simulator contributed
5519 by the European Space Agency. The simulator is not built into
5520 Sparc targets by default; configure with --enable-sim to include it.
5524 For target configurations that may include multiple variants of a
5525 basic architecture (such as MIPS and SH), you may now set the
5526 architecture explicitly. "set arch" sets, "info arch" lists
5527 the possible architectures.
5529 *** Changes in GDB-4.16:
5531 * New native configurations
5533 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5534 M68K NetBSD m68k-*-netbsd*
5535 PowerPC AIX 4.x powerpc-*-aix*
5536 PowerPC MacOS powerpc-*-macos*
5537 PowerPC Windows NT powerpcle-*-cygwin32
5538 RS/6000 AIX 4.x rs6000-*-aix4*
5542 ARM with RDP protocol arm-*-*
5543 I960 with MON960 i960-*-coff
5544 MIPS VxWorks mips*-*-vxworks*
5545 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5546 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5548 Matra Sparclet sparclet-*-*
5552 The powerpc-eabi configuration now includes the PSIM simulator,
5553 contributed by Andrew Cagney, with assistance from Mike Meissner.
5554 PSIM is a very elaborate model of the PowerPC, including not only
5555 basic instruction set execution, but also details of execution unit
5556 performance and I/O hardware. See sim/ppc/README for more details.
5560 GDB now works with Solaris 2.5.
5562 * Windows 95/NT native
5564 GDB will now work as a native debugger on Windows 95 and Windows NT.
5565 To build it from source, you must use the "gnu-win32" environment,
5566 which uses a DLL to emulate enough of Unix to run the GNU tools.
5567 Further information, binaries, and sources are available at
5568 ftp.cygnus.com, under pub/gnu-win32.
5570 * dont-repeat command
5572 If a user-defined command includes the command `dont-repeat', then the
5573 command will not be repeated if the user just types return. This is
5574 useful if the command is time-consuming to run, so that accidental
5575 extra keystrokes don't run the same command many times.
5577 * Send break instead of ^C
5579 The standard remote protocol now includes an option to send a break
5580 rather than a ^C to the target in order to interrupt it. By default,
5581 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5583 * Remote protocol timeout
5585 The standard remote protocol includes a new variable `remotetimeout'
5586 that allows you to set the number of seconds before GDB gives up trying
5587 to read from the target. The default value is 2.
5589 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5591 By default GDB will automatically keep track of objects as they are
5592 loaded and unloaded by the dynamic linker. By using the command `set
5593 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5594 when shared library events occur, thus allowing you to set breakpoints
5595 in shared libraries which are explicitly loaded by the inferior.
5597 Note this feature does not work on hpux8. On hpux9 you must link
5598 /usr/lib/end.o into your program. This feature should work
5599 automatically on hpux10.
5601 * Irix 5.x hardware watchpoint support
5603 Irix 5 configurations now support the use of hardware watchpoints.
5605 * Mips protocol "SYN garbage limit"
5607 When debugging a Mips target using the `target mips' protocol, you
5608 may set the number of characters that GDB will ignore by setting
5609 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5610 every character. The default value is 1050.
5612 * Recording and replaying remote debug sessions
5614 If you set `remotelogfile' to the name of a file, gdb will write to it
5615 a recording of a remote debug session. This recording may then be
5616 replayed back to gdb using "gdbreplay". See gdbserver/README for
5617 details. This is useful when you have a problem with GDB while doing
5618 remote debugging; you can make a recording of the session and send it
5619 to someone else, who can then recreate the problem.
5621 * Speedups for remote debugging
5623 GDB includes speedups for downloading and stepping MIPS systems using
5624 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5625 and more efficient S-record downloading.
5627 * Memory use reductions and statistics collection
5629 GDB now uses less memory and reports statistics about memory usage.
5630 Try the `maint print statistics' command, for example.
5632 *** Changes in GDB-4.15:
5634 * Psymtabs for XCOFF
5636 The symbol reader for AIX GDB now uses partial symbol tables. This
5637 can greatly improve startup time, especially for large executables.
5639 * Remote targets use caching
5641 Remote targets now use a data cache to speed up communication with the
5642 remote side. The data cache could lead to incorrect results because
5643 it doesn't know about volatile variables, thus making it impossible to
5644 debug targets which use memory mapped I/O devices. `set remotecache
5645 off' turns the the data cache off.
5647 * Remote targets may have threads
5649 The standard remote protocol now includes support for multiple threads
5650 in the target system, using new protocol commands 'H' and 'T'. See
5651 gdb/remote.c for details.
5655 If GDB is configured with `--enable-netrom', then it will include
5656 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5657 acts as though it is a bank of ROM on the target board, but you can
5658 write into it over the network. GDB's support consists only of
5659 support for fast loading into the emulated ROM; to debug, you must use
5660 another protocol, such as standard remote protocol. The usual
5661 sequence is something like
5663 target nrom <netrom-hostname>
5665 target remote <netrom-hostname>:1235
5669 GDB now includes support for the Apple Macintosh, as a host only. It
5670 may be run as either an MPW tool or as a standalone application, and
5671 it can debug through the serial port. All the usual GDB commands are
5672 available, but to the target command, you must supply "serial" as the
5673 device type instead of "/dev/ttyXX". See mpw-README in the main
5674 directory for more information on how to build. The MPW configuration
5675 scripts */mpw-config.in support only a few targets, and only the
5676 mips-idt-ecoff target has been tested.
5680 GDB configuration now uses autoconf. This is not user-visible,
5681 but does simplify configuration and building.
5685 GDB now supports hpux10.
5687 *** Changes in GDB-4.14:
5689 * New native configurations
5691 x86 FreeBSD i[345]86-*-freebsd
5692 x86 NetBSD i[345]86-*-netbsd
5693 NS32k NetBSD ns32k-*-netbsd
5694 Sparc NetBSD sparc-*-netbsd
5698 A29K VxWorks a29k-*-vxworks
5699 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5700 CPU32 EST-300 emulator m68*-*-est*
5701 PowerPC ELF powerpc-*-elf
5704 * Alpha OSF/1 support for procfs
5706 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5707 possible to attach to running processes. As the mounting of the /proc
5708 filesystem is optional on the Alpha, GDB automatically determines
5709 the availability of /proc during startup. This can lead to problems
5710 if /proc is unmounted after GDB has been started.
5712 * Arguments to user-defined commands
5714 User commands may accept up to 10 arguments separated by whitespace.
5715 Arguments are accessed within the user command via $arg0..$arg9. A
5718 print $arg0 + $arg1 + $arg2
5720 To execute the command use:
5723 Defines the command "adder" which prints the sum of its three arguments.
5724 Note the arguments are text substitutions, so they may reference variables,
5725 use complex expressions, or even perform inferior function calls.
5727 * New `if' and `while' commands
5729 This makes it possible to write more sophisticated user-defined
5730 commands. Both commands take a single argument, which is the
5731 expression to evaluate, and must be followed by the commands to
5732 execute, one per line, if the expression is nonzero, the list being
5733 terminated by the word `end'. The `if' command list may include an
5734 `else' word, which causes the following commands to be executed only
5735 if the expression is zero.
5737 * Fortran source language mode
5739 GDB now includes partial support for Fortran 77. It will recognize
5740 Fortran programs and can evaluate a subset of Fortran expressions, but
5741 variables and functions may not be handled correctly. GDB will work
5742 with G77, but does not yet know much about symbols emitted by other
5745 * Better HPUX support
5747 Most debugging facilities now work on dynamic executables for HPPAs
5748 running hpux9 or later. You can attach to running dynamically linked
5749 processes, but by default the dynamic libraries will be read-only, so
5750 for instance you won't be able to put breakpoints in them. To change
5751 that behavior do the following before running the program:
5757 This will cause the libraries to be mapped private and read-write.
5758 To revert to the normal behavior, do this:
5764 You cannot set breakpoints or examine data in the library until after
5765 the library is loaded if the function/data symbols do not have
5768 GDB can now also read debug symbols produced by the HP C compiler on
5769 HPPAs (sorry, no C++, Fortran or 68k support).
5771 * Target byte order now dynamically selectable
5773 You can choose which byte order to use with a target system, via the
5774 commands "set endian big" and "set endian little", and you can see the
5775 current setting by using "show endian". You can also give the command
5776 "set endian auto", in which case GDB will use the byte order
5777 associated with the executable. Currently, only embedded MIPS
5778 configurations support dynamic selection of target byte order.
5780 * New DOS host serial code
5782 This version uses DPMI interrupts to handle buffered I/O, so you
5783 no longer need to run asynctsr when debugging boards connected to
5786 *** Changes in GDB-4.13:
5788 * New "complete" command
5790 This lists all the possible completions for the rest of the line, if it
5791 were to be given as a command itself. This is intended for use by emacs.
5793 * Trailing space optional in prompt
5795 "set prompt" no longer adds a space for you after the prompt you set. This
5796 allows you to set a prompt which ends in a space or one that does not.
5798 * Breakpoint hit counts
5800 "info break" now displays a count of the number of times the breakpoint
5801 has been hit. This is especially useful in conjunction with "ignore"; you
5802 can ignore a large number of breakpoint hits, look at the breakpoint info
5803 to see how many times the breakpoint was hit, then run again, ignoring one
5804 less than that number, and this will get you quickly to the last hit of
5807 * Ability to stop printing at NULL character
5809 "set print null-stop" will cause GDB to stop printing the characters of
5810 an array when the first NULL is encountered. This is useful when large
5811 arrays actually contain only short strings.
5813 * Shared library breakpoints
5815 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5816 breakpoints in shared libraries before the executable is run.
5818 * Hardware watchpoints
5820 There is a new hardware breakpoint for the watch command for sparclite
5821 targets. See gdb/sparclite/hw_breakpoint.note.
5823 Hardware watchpoints are also now supported under GNU/Linux.
5827 Annotations have been added. These are for use with graphical interfaces,
5828 and are still experimental. Currently only gdba.el uses these.
5830 * Improved Irix 5 support
5832 GDB now works properly with Irix 5.2.
5834 * Improved HPPA support
5836 GDB now works properly with the latest GCC and GAS.
5838 * New native configurations
5840 Sequent PTX4 i[34]86-sequent-ptx4
5841 HPPA running OSF/1 hppa*-*-osf*
5842 Atari TT running SVR4 m68*-*-sysv4*
5843 RS/6000 LynxOS rs6000-*-lynxos*
5847 OS/9000 i[34]86-*-os9k
5848 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5851 * Hitachi SH7000 and E7000-PC ICE support
5853 There is now support for communicating with the Hitachi E7000-PC ICE.
5854 This is available automatically when GDB is configured for the SH.
5858 As usual, a variety of small fixes and improvements, both generic
5859 and configuration-specific. See the ChangeLog for more detail.
5861 *** Changes in GDB-4.12:
5863 * Irix 5 is now supported
5867 GDB-4.12 on the HPPA has a number of changes which make it unable
5868 to debug the output from the currently released versions of GCC and
5869 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5870 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5871 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5874 *** Changes in GDB-4.11:
5876 * User visible changes:
5880 The "set remotedebug" option is now consistent between the mips remote
5881 target, remote targets using the gdb-specific protocol, UDI (AMD's
5882 debug protocol for the 29k) and the 88k bug monitor. It is now an
5883 integer specifying a debug level (normally 0 or 1, but 2 means more
5884 debugging info for the mips target).
5886 * DEC Alpha native support
5888 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5889 debug info, but GDB works fairly well with the DEC compiler and should
5890 work with a future GCC release. See the README file for a few
5891 Alpha-specific notes.
5893 * Preliminary thread implementation
5895 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5897 * LynxOS native and target support for 386
5899 This release has been hosted on LynxOS 2.2, and also can be configured
5900 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5903 * Improvements in C++ mangling/demangling.
5905 This release has much better g++ debugging, specifically in name
5906 mangling/demangling, virtual function calls, print virtual table,
5907 call methods, ...etc.
5909 *** Changes in GDB-4.10:
5911 * User visible changes:
5913 Remote debugging using the GDB-specific (`target remote') protocol now
5914 supports the `load' command. This is only useful if you have some
5915 other way of getting the stub to the target system, and you can put it
5916 somewhere in memory where it won't get clobbered by the download.
5918 Filename completion now works.
5920 When run under emacs mode, the "info line" command now causes the
5921 arrow to point to the line specified. Also, "info line" prints
5922 addresses in symbolic form (as well as hex).
5924 All vxworks based targets now support a user settable option, called
5925 vxworks-timeout. This option represents the number of seconds gdb
5926 should wait for responses to rpc's. You might want to use this if
5927 your vxworks target is, perhaps, a slow software simulator or happens
5928 to be on the far side of a thin network line.
5932 This release contains support for using a DEC alpha as a GDB host for
5933 cross debugging. Native alpha debugging is not supported yet.
5936 *** Changes in GDB-4.9:
5940 This is the first GDB release which is accompanied by a matching testsuite.
5941 The testsuite requires installation of dejagnu, which should be available
5942 via ftp from most sites that carry GNU software.
5946 'Cfront' style demangling has had its name changed to 'ARM' style, to
5947 emphasize that it was written from the specifications in the C++ Annotated
5948 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5949 disclaimers, it still generated too much confusion with users attempting to
5950 use gdb with AT&T cfront.
5954 GDB now uses a standard remote interface to a simulator library.
5955 So far, the library contains simulators for the Zilog Z8001/2, the
5956 Hitachi H8/300, H8/500 and Super-H.
5958 * New targets supported
5960 H8/300 simulator h8300-hitachi-hms or h8300hms
5961 H8/500 simulator h8500-hitachi-hms or h8500hms
5962 SH simulator sh-hitachi-hms or sh
5963 Z8000 simulator z8k-zilog-none or z8ksim
5964 IDT MIPS board over serial line mips-idt-ecoff
5966 Cross-debugging to GO32 targets is supported. It requires a custom
5967 version of the i386-stub.c module which is integrated with the
5968 GO32 memory extender.
5970 * New remote protocols
5972 MIPS remote debugging protocol.
5974 * New source languages supported
5976 This version includes preliminary support for Chill, a Pascal like language
5977 used by telecommunications companies. Chill support is also being integrated
5978 into the GNU compiler, but we don't know when it will be publically available.
5981 *** Changes in GDB-4.8:
5983 * HP Precision Architecture supported
5985 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5986 version of this support was available as a set of patches from the
5987 University of Utah. GDB does not support debugging of programs
5988 compiled with the HP compiler, because HP will not document their file
5989 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5990 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5992 Many problems in the preliminary version have been fixed.
5994 * Faster and better demangling
5996 We have improved template demangling and fixed numerous bugs in the GNU style
5997 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5998 character types (wchar_t) are now supported. Demangling of each symbol is now
5999 only done once, and is cached when the symbol table for a file is read in.
6000 This results in a small increase in memory usage for C programs, a moderate
6001 increase in memory usage for C++ programs, and a fantastic speedup in
6004 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6005 from the specifications in the Annotated Reference Manual, which AT&T's
6006 compiler does not actually implement.
6008 * G++ multiple inheritance compiler problem
6010 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6011 inheritance lattices was reworked to properly discover ambiguities. We
6012 recently found an example which causes this new algorithm to fail in a
6013 very subtle way, producing bad debug information for those classes.
6014 The file 'gcc.patch' (in this directory) can be applied to gcc to
6015 circumvent the problem. A future GCC release will contain a complete
6018 The previous G++ debug info problem (mentioned below for the gdb-4.7
6019 release) is fixed in gcc version 2.3.2.
6021 * Improved configure script
6023 The `configure' script will now attempt to guess your system type if
6024 you don't supply a host system type. The old scheme of supplying a
6025 host system triplet is preferable over using this. All the magic is
6026 done in the new `config.guess' script. Examine it for details.
6028 We have also brought our configure script much more in line with the FSF's
6029 version. It now supports the --with-xxx options. In particular,
6030 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6031 The resulting GDB will not be able to read arbitrary object file formats --
6032 only the format ``expected'' to be used on the configured target system.
6033 We hope to make this the default in a future release.
6035 * Documentation improvements
6037 There's new internal documentation on how to modify GDB, and how to
6038 produce clean changes to the code. We implore people to read it
6039 before submitting changes.
6041 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6042 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6043 `info' files are also provided. To build `info' files from scratch,
6044 you will need the latest `makeinfo' release, which will be available in
6045 a future texinfo-X.Y release.
6047 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6048 We're not sure exactly which versions have this problem, but it has
6049 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6050 or better. If that isn't possible, there is a patch in
6051 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6052 around this problem.
6056 GDB now supports array constants that can be used in expressions typed in by
6057 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6058 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6061 The new directory `gdb/sparclite' contains a program that demonstrates
6062 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6064 * New native hosts supported
6066 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6067 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6069 * New targets supported
6071 AMD 29k family via UDI a29k-amd-udi or udi29k
6073 * New file formats supported
6075 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6076 HPUX core files, and SCO 3.2v2 core files.
6080 Attaching to processes now works again; thanks for the many bug reports.
6082 We have also stomped on a bunch of core dumps caused by
6083 printf_filtered("%s") problems.
6085 We eliminated a copyright problem on the rpc and ptrace header files
6086 for VxWorks, which was discovered at the last minute during the 4.7
6087 release. You should now be able to build a VxWorks GDB.
6089 You can now interrupt gdb while an attached process is running. This
6090 will cause the attached process to stop, and give control back to GDB.
6092 We fixed problems caused by using too many file descriptors
6093 for reading symbols from object files and libraries. This was
6094 especially a problem for programs that used many (~100) shared
6097 The `step' command now only enters a subroutine if there is line number
6098 information for the subroutine. Otherwise it acts like the `next'
6099 command. Previously, `step' would enter subroutines if there was
6100 any debugging information about the routine. This avoids problems
6101 when using `cc -g1' on MIPS machines.
6103 * Internal improvements
6105 GDB's internal interfaces have been improved to make it easier to support
6106 debugging of multiple languages in the future.
6108 GDB now uses a common structure for symbol information internally.
6109 Minimal symbols (derived from linkage symbols in object files), partial
6110 symbols (from a quick scan of debug information), and full symbols
6111 contain a common subset of information, making it easier to write
6112 shared code that handles any of them.
6114 * New command line options
6116 We now accept --silent as an alias for --quiet.
6120 The memory-mapped-malloc library is now licensed under the GNU Library
6121 General Public License.
6123 *** Changes in GDB-4.7:
6125 * Host/native/target split
6127 GDB has had some major internal surgery to untangle the support for
6128 hosts and remote targets. Now, when you configure GDB for a remote
6129 target, it will no longer load in all of the support for debugging
6130 local programs on the host. When fully completed and tested, this will
6131 ensure that arbitrary host/target combinations are possible.
6133 The primary conceptual shift is to separate the non-portable code in
6134 GDB into three categories. Host specific code is required any time GDB
6135 is compiled on that host, regardless of the target. Target specific
6136 code relates to the peculiarities of the target, but can be compiled on
6137 any host. Native specific code is everything else: it can only be
6138 built when the host and target are the same system. Child process
6139 handling and core file support are two common `native' examples.
6141 GDB's use of /proc for controlling Unix child processes is now cleaner.
6142 It has been split out into a single module under the `target_ops' vector,
6143 plus two native-dependent functions for each system that uses /proc.
6145 * New hosts supported
6147 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6148 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6149 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6151 * New targets supported
6153 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6154 68030 and CPU32 m68030-*-*, m68332-*-*
6156 * New native hosts supported
6158 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6159 (386bsd is not well tested yet)
6160 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6162 * New file formats supported
6164 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6165 supports reading of `a.out.adobe' object files, which are an a.out
6166 format extended with minimal information about multiple sections.
6170 `show copying' is the same as the old `info copying'.
6171 `show warranty' is the same as `info warrantee'.
6172 These were renamed for consistency. The old commands continue to work.
6174 `info handle' is a new alias for `info signals'.
6176 You can now define pre-command hooks, which attach arbitrary command
6177 scripts to any command. The commands in the hook will be executed
6178 prior to the user's command. You can also create a hook which will be
6179 executed whenever the program stops. See gdb.texinfo.
6183 We now deal with Cfront style name mangling, and can even extract type
6184 info from mangled symbols. GDB can automatically figure out which
6185 symbol mangling style your C++ compiler uses.
6187 Calling of methods and virtual functions has been improved as well.
6191 The crash that occured when debugging Sun Ansi-C compiled binaries is
6192 fixed. This was due to mishandling of the extra N_SO stabs output
6195 We also finally got Ultrix 4.2 running in house, and fixed core file
6196 support, with help from a dozen people on the net.
6198 John M. Farrell discovered that the reason that single-stepping was so
6199 slow on all of the Mips based platforms (primarily SGI and DEC) was
6200 that we were trying to demangle and lookup a symbol used for internal
6201 purposes on every instruction that was being stepped through. Changing
6202 the name of that symbol so that it couldn't be mistaken for a C++
6203 mangled symbol sped things up a great deal.
6205 Rich Pixley sped up symbol lookups in general by getting much smarter
6206 about when C++ symbol mangling is necessary. This should make symbol
6207 completion (TAB on the command line) much faster. It's not as fast as
6208 we'd like, but it's significantly faster than gdb-4.6.
6212 A new user controllable variable 'call_scratch_address' can
6213 specify the location of a scratch area to be used when GDB
6214 calls a function in the target. This is necessary because the
6215 usual method of putting the scratch area on the stack does not work
6216 in systems that have separate instruction and data spaces.
6218 We integrated changes to support the 29k UDI (Universal Debugger
6219 Interface), but discovered at the last minute that we didn't have all
6220 of the appropriate copyright paperwork. We are working with AMD to
6221 resolve this, and hope to have it available soon.
6225 We have sped up the remote serial line protocol, especially for targets
6226 with lots of registers. It now supports a new `expedited status' ('T')
6227 message which can be used in place of the existing 'S' status message.
6228 This allows the remote stub to send only the registers that GDB
6229 needs to make a quick decision about single-stepping or conditional
6230 breakpoints, eliminating the need to fetch the entire register set for
6231 each instruction being stepped through.
6233 The GDB remote serial protocol now implements a write-through cache for
6234 registers, only re-reading the registers if the target has run.
6236 There is also a new remote serial stub for SPARC processors. You can
6237 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6238 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6239 processor with a serial port.
6243 Configure.in files have become much easier to read and modify. A new
6244 `table driven' format makes it more obvious what configurations are
6245 supported, and what files each one uses.
6249 There is a new opcodes library which will eventually contain all of the
6250 disassembly routines and opcode tables. At present, it only contains
6251 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6252 disassembler (binutils/objdump) to share these routines.
6254 The libiberty library is now copylefted under the GNU Library General
6255 Public License. This allows more liberal use, and was done so libg++
6256 can use it. This makes no difference to GDB, since the Library License
6257 grants all the rights from the General Public License.
6261 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6262 reference to the stabs symbol info used by the debugger. It is (as far
6263 as we know) the only published document on this fascinating topic. We
6264 encourage you to read it, compare it to the stabs information on your
6265 system, and send improvements on the document in general (to
6266 bug-gdb@prep.ai.mit.edu).
6268 And, of course, many bugs have been fixed.
6271 *** Changes in GDB-4.6:
6273 * Better support for C++ function names
6275 GDB now accepts as input the "demangled form" of C++ overloaded function
6276 names and member function names, and can do command completion on such names
6277 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6278 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6279 Make use of command completion, it is your friend.
6281 GDB also now accepts a variety of C++ mangled symbol formats. They are
6282 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6283 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6284 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6285 for the list of formats.
6287 * G++ symbol mangling problem
6289 Recent versions of gcc have a bug in how they emit debugging information for
6290 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6291 directory) can be applied to gcc to fix the problem. Alternatively, if you
6292 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6293 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6294 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6297 * New 'maintenance' command
6299 All of the commands related to hacking GDB internals have been moved out of
6300 the main command set, and now live behind the 'maintenance' command. This
6301 can also be abbreviated as 'mt'. The following changes were made:
6303 dump-me -> maintenance dump-me
6304 info all-breakpoints -> maintenance info breakpoints
6305 printmsyms -> maintenance print msyms
6306 printobjfiles -> maintenance print objfiles
6307 printpsyms -> maintenance print psymbols
6308 printsyms -> maintenance print symbols
6310 The following commands are new:
6312 maintenance demangle Call internal GDB demangler routine to
6313 demangle a C++ link name and prints the result.
6314 maintenance print type Print a type chain for a given symbol
6316 * Change to .gdbinit file processing
6318 We now read the $HOME/.gdbinit file before processing the argv arguments
6319 (e.g. reading symbol files or core files). This allows global parameters to
6320 be set, which will apply during the symbol reading. The ./.gdbinit is still
6321 read after argv processing.
6323 * New hosts supported
6325 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6327 GNU/Linux support i386-unknown-linux or linux
6329 We are also including code to support the HP/PA running BSD and HPUX. This
6330 is almost guaranteed not to work, as we didn't have time to test or build it
6331 for this release. We are including it so that the more adventurous (or
6332 masochistic) of you can play with it. We also had major problems with the
6333 fact that the compiler that we got from HP doesn't support the -g option.
6336 * New targets supported
6338 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6340 * More smarts about finding #include files
6342 GDB now remembers the compilation directory for all include files, and for
6343 all files from which C is generated (like yacc and lex sources). This
6344 greatly improves GDB's ability to find yacc/lex sources, and include files,
6345 especially if you are debugging your program from a directory different from
6346 the one that contains your sources.
6348 We also fixed a bug which caused difficulty with listing and setting
6349 breakpoints in include files which contain C code. (In the past, you had to
6350 try twice in order to list an include file that you hadn't looked at before.)
6352 * Interesting infernals change
6354 GDB now deals with arbitrary numbers of sections, where the symbols for each
6355 section must be relocated relative to that section's landing place in the
6356 target's address space. This work was needed to support ELF with embedded
6357 stabs used by Solaris-2.0.
6359 * Bug fixes (of course!)
6361 There have been loads of fixes for the following things:
6362 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6363 i960, stabs, DOS(GO32), procfs, etc...
6365 See the ChangeLog for details.
6367 *** Changes in GDB-4.5:
6369 * New machines supported (host and target)
6371 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6373 SGI Irix-4.x mips-sgi-irix4 or iris4
6375 * New malloc package
6377 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6378 Mmalloc is capable of handling mutiple heaps of memory. It is also
6379 capable of saving a heap to a file, and then mapping it back in later.
6380 This can be used to greatly speedup the startup of GDB by using a
6381 pre-parsed symbol table which lives in a mmalloc managed heap. For
6382 more details, please read mmalloc/mmalloc.texi.
6386 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6387 'help info proc' for details.
6389 * MIPS ecoff symbol table format
6391 The code that reads MIPS symbol table format is now supported on all hosts.
6392 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6395 * File name changes for MS-DOS
6397 Many files in the config directories have been renamed to make it easier to
6398 support GDB on MS-DOSe systems (which have very restrictive file name
6399 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6400 environment) is close to working but has some remaining problems. Note
6401 that debugging of DOS programs is not supported, due to limitations
6402 in the ``operating system'', but it can be used to host cross-debugging.
6404 * Cross byte order fixes
6406 Many fixes have been made to support cross debugging of Sparc and MIPS
6407 targets from hosts whose byte order differs.
6409 * New -mapped and -readnow options
6411 If memory-mapped files are available on your system through the 'mmap'
6412 system call, you can use the -mapped option on the `file' or
6413 `symbol-file' commands to cause GDB to write the symbols from your
6414 program into a reusable file. If the program you are debugging is
6415 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6416 Future GDB debugging sessions will notice the presence of this file,
6417 and will quickly map in symbol information from it, rather than reading
6418 the symbol table from the executable program. Using the '-mapped'
6419 option in a GDB `file' or `symbol-file' command has the same effect as
6420 starting GDB with the '-mapped' command-line option.
6422 You can cause GDB to read the entire symbol table immediately by using
6423 the '-readnow' option with any of the commands that load symbol table
6424 information (or on the GDB command line). This makes the command
6425 slower, but makes future operations faster.
6427 The -mapped and -readnow options are typically combined in order to
6428 build a `fred.syms' file that contains complete symbol information.
6429 A simple GDB invocation to do nothing but build a `.syms' file for future
6432 gdb -batch -nx -mapped -readnow programname
6434 The `.syms' file is specific to the host machine on which GDB is run.
6435 It holds an exact image of GDB's internal symbol table. It cannot be
6436 shared across multiple host platforms.
6438 * longjmp() handling
6440 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6441 siglongjmp() without losing control. This feature has not yet been ported to
6442 all systems. It currently works on many 386 platforms, all MIPS-based
6443 platforms (SGI, DECstation, etc), and Sun3/4.
6447 Preliminary work has been put in to support the new Solaris OS from Sun. At
6448 this time, it can control and debug processes, but it is not capable of
6453 As always, many many bug fixes. The major areas were with g++, and mipsread.
6454 People using the MIPS-based platforms should experience fewer mysterious
6455 crashes and trashed symbol tables.
6457 *** Changes in GDB-4.4:
6459 * New machines supported (host and target)
6461 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6463 BSD Reno on Vax vax-dec-bsd
6464 Ultrix on Vax vax-dec-ultrix
6466 * New machines supported (target)
6468 AMD 29000 embedded, using EBMON a29k-none-none
6472 GDB continues to improve its handling of C++. `References' work better.
6473 The demangler has also been improved, and now deals with symbols mangled as
6474 per the Annotated C++ Reference Guide.
6476 GDB also now handles `stabs' symbol information embedded in MIPS
6477 `ecoff' symbol tables. Since the ecoff format was not easily
6478 extensible to handle new languages such as C++, this appeared to be a
6479 good way to put C++ debugging info into MIPS binaries. This option
6480 will be supported in the GNU C compiler, version 2, when it is
6483 * New features for SVR4
6485 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6486 shared libraries. Debugging dynamically linked programs should present
6487 only minor differences from debugging statically linked programs.
6489 The `info proc' command will print out information about any process
6490 on an SVR4 system (including the one you are debugging). At the moment,
6491 it prints the address mappings of the process.
6493 If you bring up GDB on another SVR4 system, please send mail to
6494 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6496 * Better dynamic linking support in SunOS
6498 Reading symbols from shared libraries which contain debugging symbols
6499 now works properly. However, there remain issues such as automatic
6500 skipping of `transfer vector' code during function calls, which
6501 make it harder to debug code in a shared library, than to debug the
6502 same code linked statically.
6506 GDB is now using the latest `getopt' routines from the FSF. This
6507 version accepts the -- prefix for options with long names. GDB will
6508 continue to accept the old forms (-option and +option) as well.
6509 Various single letter abbreviations for options have been explicity
6510 added to the option table so that they won't get overshadowed in the
6511 future by other options that begin with the same letter.
6515 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6516 Many assorted bugs have been handled. Many more remain to be handled.
6517 See the various ChangeLog files (primarily in gdb and bfd) for details.
6520 *** Changes in GDB-4.3:
6522 * New machines supported (host and target)
6524 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6525 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6526 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6528 * Almost SCO Unix support
6530 We had hoped to support:
6531 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6532 (except for core file support), but we discovered very late in the release
6533 that it has problems with process groups that render gdb unusable. Sorry
6534 about that. I encourage people to fix it and post the fixes.
6536 * Preliminary ELF and DWARF support
6538 GDB can read ELF object files on System V Release 4, and can handle
6539 debugging records for C, in DWARF format, in ELF files. This support
6540 is preliminary. If you bring up GDB on another SVR4 system, please
6541 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6546 GDB now uses the latest `readline' library. One user-visible change
6547 is that two tabs will list possible command completions, which previously
6548 required typing M-? (meta-question mark, or ESC ?).
6552 The `stepi' bug that many of you noticed has been squashed.
6553 Many bugs in C++ have been handled. Many more remain to be handled.
6554 See the various ChangeLog files (primarily in gdb and bfd) for details.
6556 * State of the MIPS world (in case you wondered):
6558 GDB can understand the symbol tables emitted by the compilers
6559 supplied by most vendors of MIPS-based machines, including DEC. These
6560 symbol tables are in a format that essentially nobody else uses.
6562 Some versions of gcc come with an assembler post-processor called
6563 mips-tfile. This program is required if you want to do source-level
6564 debugging of gcc-compiled programs. I believe FSF does not ship
6565 mips-tfile with gcc version 1, but it will eventually come with gcc
6568 Debugging of g++ output remains a problem. g++ version 1.xx does not
6569 really support it at all. (If you're lucky, you should be able to get
6570 line numbers and stack traces to work, but no parameters or local
6571 variables.) With some work it should be possible to improve the
6574 When gcc version 2 is released, you will have somewhat better luck.
6575 However, even then you will get confusing results for inheritance and
6578 We will eventually provide full debugging of g++ output on
6579 DECstations. This will probably involve some kind of stabs-in-ecoff
6580 encapulation, but the details have not been worked out yet.
6583 *** Changes in GDB-4.2:
6585 * Improved configuration
6587 Only one copy of `configure' exists now, and it is not self-modifying.
6588 Porting BFD is simpler.
6592 The `step' and `next' commands now only stop at the first instruction
6593 of a source line. This prevents the multiple stops that used to occur
6594 in switch statements, for-loops, etc. `Step' continues to stop if a
6595 function that has debugging information is called within the line.
6599 Lots of small bugs fixed. More remain.
6601 * New host supported (not target)
6603 Intel 386 PC clone running Mach i386-none-mach
6606 *** Changes in GDB-4.1:
6608 * Multiple source language support
6610 GDB now has internal scaffolding to handle several source languages.
6611 It determines the type of each source file from its filename extension,
6612 and will switch expression parsing and number formatting to match the
6613 language of the function in the currently selected stack frame.
6614 You can also specifically set the language to be used, with
6615 `set language c' or `set language modula-2'.
6619 GDB now has preliminary support for the GNU Modula-2 compiler,
6620 currently under development at the State University of New York at
6621 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6622 continue through the fall of 1991 and into 1992.
6624 Other Modula-2 compilers are currently not supported, and attempting to
6625 debug programs compiled with them will likely result in an error as the
6626 symbol table is read. Feel free to work on it, though!
6628 There are hooks in GDB for strict type checking and range checking,
6629 in the `Modula-2 philosophy', but they do not currently work.
6633 GDB can now write to executable and core files (e.g. patch
6634 a variable's value). You must turn this switch on, specify
6635 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6636 by assigning a new value to a variable. Modifications take
6639 * Automatic SunOS shared library reading
6641 When you run your program, GDB automatically determines where its
6642 shared libraries (if any) have been loaded, and reads their symbols.
6643 The `share' command is no longer needed. This also works when
6644 examining core files.
6648 You can specify the number of lines that the `list' command shows.
6651 * New machines supported (host and target)
6653 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6654 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6655 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6657 * New hosts supported (not targets)
6659 IBM RT/PC: romp-ibm-aix or rtpc
6661 * New targets supported (not hosts)
6663 AMD 29000 embedded with COFF a29k-none-coff
6664 AMD 29000 embedded with a.out a29k-none-aout
6665 Ultracomputer remote kernel debug a29k-nyu-kern
6667 * New remote interfaces
6673 *** Changes in GDB-4.0:
6677 Wide output is wrapped at good places to make the output more readable.
6679 Gdb now supports cross-debugging from a host machine of one type to a
6680 target machine of another type. Communication with the target system
6681 is over serial lines. The ``target'' command handles connecting to the
6682 remote system; the ``load'' command will download a program into the
6683 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6684 also supports debugging of realtime processes running under VxWorks,
6685 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6686 stub on the target system.
6688 New CPUs supported include the AMD 29000 and Intel 960.
6690 GDB now reads object files and symbol tables via a ``binary file''
6691 library, which allows a single copy of GDB to debug programs of multiple
6692 object file types such as a.out and coff.
6694 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6695 refcard.dvi and refcard.ps are available to format it).
6698 * Control-Variable user interface simplified
6700 All variables that control the operation of the debugger can be set
6701 by the ``set'' command, and displayed by the ``show'' command.
6703 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6704 ``Show prompt'' produces the response:
6705 Gdb's prompt is new-gdb=>.
6707 What follows are the NEW set commands. The command ``help set'' will
6708 print a complete list of old and new set commands. ``help set FOO''
6709 will give a longer description of the variable FOO. ``show'' will show
6710 all of the variable descriptions and their current settings.
6712 confirm on/off: Enables warning questions for operations that are
6713 hard to recover from, e.g. rerunning the program while
6714 it is already running. Default is ON.
6716 editing on/off: Enables EMACS style command line editing
6717 of input. Previous lines can be recalled with
6718 control-P, the current line can be edited with control-B,
6719 you can search for commands with control-R, etc.
6722 history filename NAME: NAME is where the gdb command history
6723 will be stored. The default is .gdb_history,
6724 or the value of the environment variable
6727 history size N: The size, in commands, of the command history. The
6728 default is 256, or the value of the environment variable
6731 history save on/off: If this value is set to ON, the history file will
6732 be saved after exiting gdb. If set to OFF, the
6733 file will not be saved. The default is OFF.
6735 history expansion on/off: If this value is set to ON, then csh-like
6736 history expansion will be performed on
6737 command line input. The default is OFF.
6739 radix N: Sets the default radix for input and output. It can be set
6740 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6741 in the current radix, so "set radix 10" is always a no-op.
6743 height N: This integer value is the number of lines on a page. Default
6744 is 24, the current `stty rows'' setting, or the ``li#''
6745 setting from the termcap entry matching the environment
6748 width N: This integer value is the number of characters on a line.
6749 Default is 80, the current `stty cols'' setting, or the ``co#''
6750 setting from the termcap entry matching the environment
6753 Note: ``set screensize'' is obsolete. Use ``set height'' and
6754 ``set width'' instead.
6756 print address on/off: Print memory addresses in various command displays,
6757 such as stack traces and structure values. Gdb looks
6758 more ``symbolic'' if you turn this off; it looks more
6759 ``machine level'' with it on. Default is ON.
6761 print array on/off: Prettyprint arrays. New convenient format! Default
6764 print demangle on/off: Print C++ symbols in "source" form if on,
6767 print asm-demangle on/off: Same, for assembler level printouts
6770 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6773 * Support for Epoch Environment.
6775 The epoch environment is a version of Emacs v18 with windowing. One
6776 new command, ``inspect'', is identical to ``print'', except that if you
6777 are running in the epoch environment, the value is printed in its own
6781 * Support for Shared Libraries
6783 GDB can now debug programs and core files that use SunOS shared libraries.
6784 Symbols from a shared library cannot be referenced
6785 before the shared library has been linked with the program (this
6786 happens after you type ``run'' and before the function main() is entered).
6787 At any time after this linking (including when examining core files
6788 from dynamically linked programs), gdb reads the symbols from each
6789 shared library when you type the ``sharedlibrary'' command.
6790 It can be abbreviated ``share''.
6792 sharedlibrary REGEXP: Load shared object library symbols for files
6793 matching a unix regular expression. No argument
6794 indicates to load symbols for all shared libraries.
6796 info sharedlibrary: Status of loaded shared libraries.
6801 A watchpoint stops execution of a program whenever the value of an
6802 expression changes. Checking for this slows down execution
6803 tremendously whenever you are in the scope of the expression, but is
6804 quite useful for catching tough ``bit-spreader'' or pointer misuse
6805 problems. Some machines such as the 386 have hardware for doing this
6806 more quickly, and future versions of gdb will use this hardware.
6808 watch EXP: Set a watchpoint (breakpoint) for an expression.
6810 info watchpoints: Information about your watchpoints.
6812 delete N: Deletes watchpoint number N (same as breakpoints).
6813 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6814 enable N: Re-enables watchpoint number N (same as breakpoints).
6817 * C++ multiple inheritance
6819 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6822 * C++ exception handling
6824 Gdb now supports limited C++ exception handling. Besides the existing
6825 ability to breakpoint on an exception handler, gdb can breakpoint on
6826 the raising of an exception (before the stack is peeled back to the
6829 catch FOO: If there is a FOO exception handler in the dynamic scope,
6830 set a breakpoint to catch exceptions which may be raised there.
6831 Multiple exceptions (``catch foo bar baz'') may be caught.
6833 info catch: Lists all exceptions which may be caught in the
6834 current stack frame.
6837 * Minor command changes
6839 The command ``call func (arg, arg, ...)'' now acts like the print
6840 command, except it does not print or save a value if the function's result
6841 is void. This is similar to dbx usage.
6843 The ``up'' and ``down'' commands now always print the frame they end up
6844 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6845 frames without printing.
6847 * New directory command
6849 'dir' now adds directories to the FRONT of the source search path.
6850 The path starts off empty. Source files that contain debug information
6851 about the directory in which they were compiled can be found even
6852 with an empty path; Sun CC and GCC include this information. If GDB can't
6853 find your source file in the current directory, type "dir .".
6855 * Configuring GDB for compilation
6857 For normal use, type ``./configure host''. See README or gdb.texinfo
6860 GDB now handles cross debugging. If you are remotely debugging between
6861 two different machines, type ``./configure host -target=targ''.
6862 Host is the machine where GDB will run; targ is the machine
6863 where the program that you are debugging will run.