1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * New "--readnever" command line option instructs GDB to not read each
7 symbol file's symbolic debug information. This makes startup faster
8 but at the expense of not being able to perform symbolic debugging.
9 This option is intended for use cases where symbolic debugging will
10 not be used, e.g., when you only need to dump the debuggee's core.
12 * GDB now uses the GNU MPFR library, if available, to emulate target
13 floating-point arithmetic during expression evaluation when the target
14 uses different floating-point formats than the host. At least version
15 3.1 of GNU MPFR is required.
17 * GDB now supports access to the guarded-storage-control registers and the
18 software-based guarded-storage broadcast control registers on IBM z14.
20 * On Unix systems, GDB now supports transmitting environment variables
21 that are to be set or unset to GDBserver. These variables will
22 affect the environment to be passed to the remote inferior.
24 To inform GDB of environment variables that are to be transmitted to
25 GDBserver, use the "set environment" command. Only user set
26 environment variables are sent to GDBserver.
28 To inform GDB of environment variables that are to be unset before
29 the remote inferior is started by the GDBserver, use the "unset
32 * Completion improvements
34 ** GDB can now complete function parameters in linespecs and
35 explicit locations without quoting. When setting breakpoints,
36 quoting around functions names to help with TAB-completion is
37 generally no longer necessary. For example, this now completes
40 (gdb) b function(in[TAB]
43 Related, GDB is no longer confused with completing functions in
44 C++ anonymous namespaces:
47 (gdb) b (anonymous namespace)::[TAB][TAB]
48 (anonymous namespace)::a_function()
49 (anonymous namespace)::b_function()
51 ** GDB now has much improved linespec and explicit locations TAB
52 completion support, that better understands what you're
53 completing and offers better suggestions. For example, GDB no
54 longer offers data symbols as possible completions when you're
57 ** GDB now TAB-completes label symbol names.
59 ** The "complete" command now mimics TAB completion accurately.
61 * New command line options (gcore)
64 Dump all memory mappings.
66 * Breakpoints on C++ functions are now set on all scopes by default
68 By default, breakpoints on functions/methods are now interpreted as
69 specifying all functions with the given name ignoring missing
70 leading scopes (namespaces and classes).
72 For example, assuming a C++ program with symbols named:
77 both commands "break func()" and "break B::func()" set a breakpoint
80 You can use the new flag "-qualified" to override this. This makes
81 GDB interpret the specified function name as a complete
82 fully-qualified name instead. For example, using the same C++
83 program, the "break -q B::func" command sets a breakpoint on
86 * Breakpoints on functions marked with C++ ABI tags
88 GDB can now set breakpoints on functions marked with C++ ABI tags
89 (e.g., [abi:cxx11]). See here for a description of ABI tags:
90 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
92 Functions with a C++11 abi tag are demangled/displayed like this:
94 function[abi:cxx11](int)
97 You can now set a breakpoint on such functions simply as if they had
100 (gdb) b function(int)
102 Or if you need to disambiguate between tags, like:
104 (gdb) b function[abi:other_tag](int)
106 Tab completion was adjusted accordingly as well.
110 ** New events gdb.new_inferior, gdb.inferior_deleted, and
111 gdb.new_thread are emitted. See the manual for further
112 description of these.
114 ** A new command, "rbreak" has been added to the Python API. This
115 command allows the setting of a large number of breakpoints via a
116 regex pattern in Python. See the manual for further details.
118 ** Python breakpoints can now accept explicit locations. See the
119 manual for a further description of this feature.
122 * New features in the GDB remote stub, GDBserver
124 ** GDBserver is now able to start inferior processes with a
125 specified initial working directory.
127 The user can set the desired working directory to be used from
128 GDB using the new "set cwd" command.
130 ** New "--selftest" command line option runs some GDBserver self
131 tests. These self tests are disabled in releases.
133 ** On Unix systems, GDBserver now does globbing expansion and variable
134 substitution in inferior command line arguments.
136 This is done by starting inferiors using a shell, like GDB does.
137 See "set startup-with-shell" in the user manual for how to disable
138 this from GDB when using "target extended-remote". When using
139 "target remote", you can disable the startup with shell by using the
140 new "--no-startup-with-shell" GDBserver command line option.
142 ** On Unix systems, GDBserver now supports receiving environment
143 variables that are to be set or unset from GDB. These variables
144 will affect the environment to be passed to the inferior.
146 * When catching an Ada exception raised with a message, GDB now prints
147 the message in the catchpoint hit notification. In GDB/MI mode, that
148 information is provided as an extra field named "exception-message"
149 in the *stopped notification.
151 * Trait objects can now be inspected When debugging Rust code. This
152 requires compiler support which will appear in Rust 1.24.
156 QEnvironmentHexEncoded
157 Inform GDBserver of an environment variable that is to be passed to
158 the inferior when starting it.
161 Inform GDBserver of an environment variable that is to be unset
162 before starting the remote inferior.
165 Inform GDBserver that the environment should be reset (i.e.,
166 user-set environment variables should be unset).
169 Indicates whether the inferior must be started with a shell or not.
172 Tell GDBserver that the inferior to be started should use a specific
175 * The "maintenance print c-tdesc" command now takes an optional
176 argument which is the file name of XML target description.
178 * The "maintenance selftest" command now takes an optional argument to
179 filter the tests to be run.
181 * The "enable", and "disable" commands now accept a range of
182 breakpoint locations, e.g. "enable 1.3-5".
187 Set and show the current working directory for the inferior.
190 Set and show compilation command used for compiling and injecting code
191 with the 'compile' commands.
193 set debug separate-debug-file
194 show debug separate-debug-file
195 Control the display of debug output about separate debug file search.
197 set dump-excluded-mappings
198 show dump-excluded-mappings
199 Control whether mappings marked with the VM_DONTDUMP flag should be
200 dumped when generating a core file.
203 List the registered selftests.
206 Start the debugged program stopping at the first instruction.
208 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
211 * Safer/improved support for debugging with no debug info
213 GDB no longer assumes functions with no debug information return
216 This means that GDB now refuses to call such functions unless you
217 tell it the function's type, by either casting the call to the
218 declared return type, or by casting the function to a function
219 pointer of the right type, and calling that:
221 (gdb) p getenv ("PATH")
222 'getenv' has unknown return type; cast the call to its declared return type
223 (gdb) p (char *) getenv ("PATH")
224 $1 = 0x7fffffffe "/usr/local/bin:/"...
225 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
226 $2 = 0x7fffffffe "/usr/local/bin:/"...
228 Similarly, GDB no longer assumes that global variables with no debug
229 info have type 'int', and refuses to print the variable's value
230 unless you tell it the variable's type:
233 'var' has unknown type; cast it to its declared type
237 * New native configurations
239 FreeBSD/aarch64 aarch64*-*-freebsd*
240 FreeBSD/arm arm*-*-freebsd*
244 FreeBSD/aarch64 aarch64*-*-freebsd*
245 FreeBSD/arm arm*-*-freebsd*
247 * Removed targets and native configurations
249 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
251 *** Changes in GDB 8.0
253 * GDB now supports access to the PKU register on GNU/Linux. The register is
254 added by the Memory Protection Keys for Userspace feature which will be
255 available in future Intel CPUs.
257 * GDB now supports C++11 rvalue references.
261 ** New functions to start, stop and access a running btrace recording.
262 ** Rvalue references are now supported in gdb.Type.
264 * GDB now supports recording and replaying rdrand and rdseed Intel 64
267 * Building GDB and GDBserver now requires a C++11 compiler.
269 For example, GCC 4.8 or later.
271 It is no longer possible to build GDB or GDBserver with a C
272 compiler. The --disable-build-with-cxx configure option has been
275 * Building GDB and GDBserver now requires GNU make >= 3.81.
277 It is no longer supported to build GDB or GDBserver with another
278 implementation of the make program or an earlier version of GNU make.
280 * Native debugging on MS-Windows supports command-line redirection
282 Command-line arguments used for starting programs on MS-Windows can
283 now include redirection symbols supported by native Windows shells,
284 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
285 as "run", "start", and "set args", as well as the corresponding MI
288 * Support for thread names on MS-Windows.
290 GDB now catches and handles the special exception that programs
291 running on MS-Windows use to assign names to threads in the
294 * Support for Java programs compiled with gcj has been removed.
296 * User commands now accept an unlimited number of arguments.
297 Previously, only up to 10 was accepted.
299 * The "eval" command now expands user-defined command arguments.
301 This makes it easier to process a variable number of arguments:
306 eval "print $arg%d", $i
311 * Target descriptions can now describe registers for sparc32 and sparc64.
313 * GDB now supports DWARF version 5 (debug information format).
314 Its .debug_names index is not yet supported.
316 * New native configurations
318 FreeBSD/mips mips*-*-freebsd
322 Synopsys ARC arc*-*-elf32
323 FreeBSD/mips mips*-*-freebsd
325 * Removed targets and native configurations
327 Alpha running FreeBSD alpha*-*-freebsd*
328 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
333 Erases all the flash memory regions reported by the target.
335 maint print arc arc-instruction address
336 Print internal disassembler information about instruction at a given address.
340 set disassembler-options
341 show disassembler-options
342 Controls the passing of target specific information to the disassembler.
343 If it is necessary to specify more than one disassembler option then
344 multiple options can be placed together into a comma separated list.
345 The default value is the empty string. Currently, the only supported
346 targets are ARM, PowerPC and S/390.
351 Erases all the flash memory regions reported by the target. This is
352 equivalent to the CLI command flash-erase.
354 -file-list-shared-libraries
355 List the shared libraries in the program. This is
356 equivalent to the CLI command "info shared".
358 *** Changes in GDB 7.12
360 * GDB and GDBserver now build with a C++ compiler by default.
362 The --enable-build-with-cxx configure option is now enabled by
363 default. One must now explicitly configure with
364 --disable-build-with-cxx in order to build with a C compiler. This
365 option will be removed in a future release.
367 * GDBserver now supports recording btrace without maintaining an active
370 * GDB now supports a negative repeat count in the 'x' command to examine
371 memory backward from the given address. For example:
374 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
375 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
376 (gdb) x/-5i 0x0000000000400580
377 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
378 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
379 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
380 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
381 0x40057b <main(int, char**)+25>:
382 callq 0x400536 <Func1(int, char const*)>
384 * Fortran: Support structures with fields of dynamic types and
385 arrays of dynamic types.
387 * The symbol dumping maintenance commands have new syntax.
388 maint print symbols [-pc address] [--] [filename]
389 maint print symbols [-objfile objfile] [-source source] [--] [filename]
390 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
391 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
392 maint print msymbols [-objfile objfile] [--] [filename]
394 * GDB now supports multibit bitfields and enums in target register
397 * New Python-based convenience function $_as_string(val), which returns
398 the textual representation of a value. This function is especially
399 useful to obtain the text label of an enum value.
401 * Intel MPX bound violation handling.
403 Segmentation faults caused by a Intel MPX boundary violation
404 now display the kind of violation (upper or lower), the memory
405 address accessed and the memory bounds, along with the usual
406 signal received and code location.
410 Program received signal SIGSEGV, Segmentation fault
411 Upper bound violation while accessing address 0x7fffffffc3b3
412 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
413 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
415 * Rust language support.
416 GDB now supports debugging programs written in the Rust programming
417 language. See https://www.rust-lang.org/ for more information about
420 * Support for running interpreters on specified input/output devices
422 GDB now supports a new mechanism that allows frontends to provide
423 fully featured GDB console views, as a better alternative to
424 building such views on top of the "-interpreter-exec console"
425 command. See the new "new-ui" command below. With that command,
426 frontends can now start GDB in the traditional command-line mode
427 running in an embedded terminal emulator widget, and create a
428 separate MI interpreter running on a specified i/o device. In this
429 way, GDB handles line editing, history, tab completion, etc. in the
430 console all by itself, and the GUI uses the separate MI interpreter
431 for its own control and synchronization, invisible to the command
434 * The "catch syscall" command catches groups of related syscalls.
436 The "catch syscall" command now supports catching a group of related
437 syscalls using the 'group:' or 'g:' prefix.
442 skip -gfile file-glob-pattern
443 skip -function function
444 skip -rfunction regular-expression
445 A generalized form of the skip command, with new support for
446 glob-style file names and regular expressions for function names.
447 Additionally, a file spec and a function spec may now be combined.
449 maint info line-table REGEXP
450 Display the contents of GDB's internal line table data struture.
453 Run any GDB unit tests that were compiled in.
456 Start a new user interface instance running INTERP as interpreter,
457 using the TTY file for input/output.
461 ** gdb.Breakpoint objects have a new attribute "pending", which
462 indicates whether the breakpoint is pending.
463 ** Three new breakpoint-related events have been added:
464 gdb.breakpoint_created, gdb.breakpoint_modified, and
465 gdb.breakpoint_deleted.
468 Signal ("set") the given MS-Windows event object. This is used in
469 conjunction with the Windows JIT debugging (AeDebug) support, where
470 the OS suspends a crashing process until a debugger can attach to
471 it. Resuming the crashing process, in order to debug it, is done by
474 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
475 was added in GDBserver, including JIT compiling fast tracepoint's
476 conditional expression bytecode into native code.
478 * Support for various remote target protocols and ROM monitors has
481 target m32rsdi Remote M32R debugging over SDI
482 target mips MIPS remote debugging protocol
483 target pmon PMON ROM monitor
484 target ddb NEC's DDB variant of PMON for Vr4300
485 target rockhopper NEC RockHopper variant of PMON
486 target lsi LSI variant of PMO
488 * Support for tracepoints and fast tracepoints on powerpc-linux,
489 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
490 including JIT compiling fast tracepoint's conditional expression
491 bytecode into native code.
493 * MI async record =record-started now includes the method and format used for
494 recording. For example:
496 =record-started,thread-group="i1",method="btrace",format="bts"
498 * MI async record =thread-selected now includes the frame field. For example:
500 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
504 Andes NDS32 nds32*-*-elf
506 *** Changes in GDB 7.11
508 * GDB now supports debugging kernel-based threads on FreeBSD.
510 * Per-inferior thread numbers
512 Thread numbers are now per inferior instead of global. If you're
513 debugging multiple inferiors, GDB displays thread IDs using a
514 qualified INF_NUM.THR_NUM form. For example:
518 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
519 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
520 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
521 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
523 As consequence, thread numbers as visible in the $_thread
524 convenience variable and in Python's InferiorThread.num attribute
525 are no longer unique between inferiors.
527 GDB now maintains a second thread ID per thread, referred to as the
528 global thread ID, which is the new equivalent of thread numbers in
529 previous releases. See also $_gthread below.
531 For backwards compatibility, MI's thread IDs always refer to global
534 * Commands that accept thread IDs now accept the qualified
535 INF_NUM.THR_NUM form as well. For example:
538 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
541 * In commands that accept a list of thread IDs, you can now refer to
542 all threads of an inferior using a star wildcard. GDB accepts
543 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
544 refer to all threads of the current inferior. For example, "info
547 * You can use "info threads -gid" to display the global thread ID of
550 * The new convenience variable $_gthread holds the global number of
553 * The new convenience variable $_inferior holds the number of the
556 * GDB now displays the ID and name of the thread that hit a breakpoint
557 or received a signal, if your program is multi-threaded. For
560 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
561 Thread 1 "main" received signal SIGINT, Interrupt.
563 * Record btrace now supports non-stop mode.
565 * Support for tracepoints on aarch64-linux was added in GDBserver.
567 * The 'record instruction-history' command now indicates speculative execution
568 when using the Intel Processor Trace recording format.
570 * GDB now allows users to specify explicit locations, bypassing
571 the linespec parser. This feature is also available to GDB/MI
574 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
575 GDB now is able to debug both AArch64 applications and ARM applications
578 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
579 including JIT compiling fast tracepoint's conditional expression bytecode
582 * GDB now supports displaced stepping on AArch64 GNU/Linux.
584 * "info threads", "info inferiors", "info display", "info checkpoints"
585 and "maint info program-spaces" now list the corresponding items in
586 ascending ID order, for consistency with all other "info" commands.
588 * In Ada, the overloads selection menu has been enhanced to display the
589 parameter types and the return types for the matching overloaded subprograms.
593 maint set target-non-stop (on|off|auto)
594 maint show target-non-stop
595 Control whether GDB targets always operate in non-stop mode even if
596 "set non-stop" is "off". The default is "auto", meaning non-stop
597 mode is enabled if supported by the target.
599 maint set bfd-sharing
600 maint show bfd-sharing
601 Control the reuse of bfd objects.
605 Control display of debugging info regarding bfd caching.
609 Control display of debugging info regarding FreeBSD threads.
611 set remote multiprocess-extensions-packet
612 show remote multiprocess-extensions-packet
613 Set/show the use of the remote protocol multiprocess extensions.
615 set remote thread-events
616 show remote thread-events
617 Set/show the use of thread create/exit events.
619 set ada print-signatures on|off
620 show ada print-signatures"
621 Control whether parameter types and return types are displayed in overloads
622 selection menus. It is activaled (@code{on}) by default.
626 Controls the maximum size of memory, in bytes, that GDB will
627 allocate for value contents. Prevents incorrect programs from
628 causing GDB to allocate overly large buffers. Default is 64k.
630 * The "disassemble" command accepts a new modifier: /s.
631 It prints mixed source+disassembly like /m with two differences:
632 - disassembled instructions are now printed in program order, and
633 - and source for all relevant files is now printed.
634 The "/m" option is now considered deprecated: its "source-centric"
635 output hasn't proved useful in practice.
637 * The "record instruction-history" command accepts a new modifier: /s.
638 It behaves exactly like /m and prints mixed source+disassembly.
640 * The "set scheduler-locking" command supports a new mode "replay".
641 It behaves like "off" in record mode and like "on" in replay mode.
643 * Support for various ROM monitors has been removed:
645 target dbug dBUG ROM monitor for Motorola ColdFire
646 target picobug Motorola picobug monitor
647 target dink32 DINK32 ROM monitor for PowerPC
648 target m32r Renesas M32R/D ROM monitor
649 target mon2000 mon2000 ROM monitor
650 target ppcbug PPCBUG ROM monitor for PowerPC
652 * Support for reading/writing memory and extracting values on architectures
653 whose memory is addressable in units of any integral multiple of 8 bits.
658 Indicates that an exec system call was executed.
660 exec-events feature in qSupported
661 The qSupported packet allows GDB to request support for exec
662 events using the new 'gdbfeature' exec-event, and the qSupported
663 response can contain the corresponding 'stubfeature'. Set and
664 show commands can be used to display whether these features are enabled.
667 Equivalent to interrupting with the ^C character, but works in
670 thread created stop reason (T05 create:...)
671 Indicates that the thread was just created and is stopped at entry.
673 thread exit stop reply (w exitcode;tid)
674 Indicates that the thread has terminated.
677 Enables/disables thread create and exit event reporting. For
678 example, this is used in non-stop mode when GDB stops a set of
679 threads and synchronously waits for the their corresponding stop
680 replies. Without exit events, if one of the threads exits, GDB
681 would hang forever not knowing that it should no longer expect a
682 stop for that same thread.
685 Indicates that there are no resumed threads left in the target (all
686 threads are stopped). The remote stub reports support for this stop
687 reply to GDB's qSupported query.
690 Enables/disables catching syscalls from the inferior process.
691 The remote stub reports support for this packet to GDB's qSupported query.
693 syscall_entry stop reason
694 Indicates that a syscall was just called.
696 syscall_return stop reason
697 Indicates that a syscall just returned.
699 * Extended-remote exec events
701 ** GDB now has support for exec events on extended-remote Linux targets.
702 For such targets with Linux kernels 2.5.46 and later, this enables
703 follow-exec-mode and exec catchpoints.
705 set remote exec-event-feature-packet
706 show remote exec-event-feature-packet
707 Set/show the use of the remote exec event feature.
709 * Thread names in remote protocol
711 The reply to qXfer:threads:read may now include a name attribute for each
714 * Target remote mode fork and exec events
716 ** GDB now has support for fork and exec events on target remote mode
717 Linux targets. For such targets with Linux kernels 2.5.46 and later,
718 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
719 fork and exec catchpoints.
721 * Remote syscall events
723 ** GDB now has support for catch syscall on remote Linux targets,
724 currently enabled on x86/x86_64 architectures.
726 set remote catch-syscall-packet
727 show remote catch-syscall-packet
728 Set/show the use of the remote catch syscall feature.
732 ** The -var-set-format command now accepts the zero-hexadecimal
733 format. It outputs data in hexadecimal format with zero-padding on the
738 ** gdb.InferiorThread objects have a new attribute "global_num",
739 which refers to the thread's global thread ID. The existing
740 "num" attribute now refers to the thread's per-inferior number.
741 See "Per-inferior thread numbers" above.
742 ** gdb.InferiorThread objects have a new attribute "inferior", which
743 is the Inferior object the thread belongs to.
745 *** Changes in GDB 7.10
747 * Support for process record-replay and reverse debugging on aarch64*-linux*
748 targets has been added. GDB now supports recording of A64 instruction set
749 including advance SIMD instructions.
751 * Support for Sun's version of the "stabs" debug file format has been removed.
753 * GDB now honors the content of the file /proc/PID/coredump_filter
754 (PID is the process ID) on GNU/Linux systems. This file can be used
755 to specify the types of memory mappings that will be included in a
756 corefile. For more information, please refer to the manual page of
757 "core(5)". GDB also has a new command: "set use-coredump-filter
758 on|off". It allows to set whether GDB will read the content of the
759 /proc/PID/coredump_filter file when generating a corefile.
761 * The "info os" command on GNU/Linux can now display information on
763 "info os cpus" Listing of all cpus/cores on the system
765 * GDB has two new commands: "set serial parity odd|even|none" and
766 "show serial parity". These allows to set or show parity for the
769 * The "info source" command now displays the producer string if it was
770 present in the debug info. This typically includes the compiler version
771 and may include things like its command line arguments.
773 * The "info dll", an alias of the "info sharedlibrary" command,
774 is now available on all platforms.
776 * Directory names supplied to the "set sysroot" commands may be
777 prefixed with "target:" to tell GDB to access shared libraries from
778 the target system, be it local or remote. This replaces the prefix
779 "remote:". The default sysroot has been changed from "" to
780 "target:". "remote:" is automatically converted to "target:" for
781 backward compatibility.
783 * The system root specified by "set sysroot" will be prepended to the
784 filename of the main executable (if reported to GDB as absolute by
785 the operating system) when starting processes remotely, and when
786 attaching to already-running local or remote processes.
788 * GDB now supports automatic location and retrieval of executable
789 files from remote targets. Remote debugging can now be initiated
790 using only a "target remote" or "target extended-remote" command
791 (no "set sysroot" or "file" commands are required). See "New remote
794 * The "dump" command now supports verilog hex format.
796 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
798 * On GNU/Linux, GDB and gdbserver are now able to access executable
799 and shared library files without a "set sysroot" command when
800 attaching to processes running in different mount namespaces from
801 the debugger. This makes it possible to attach to processes in
802 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
803 See "New remote packets" below.
805 * The "tui reg" command now provides completion for all of the
806 available register groups, including target specific groups.
808 * The HISTSIZE environment variable is no longer read when determining
809 the size of GDB's command history. GDB now instead reads the dedicated
810 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
811 disables truncation of command history. Non-numeric values of GDBHISTSIZE
816 ** Memory ports can now be unbuffered.
820 ** gdb.Objfile objects have a new attribute "username",
821 which is the name of the objfile as specified by the user,
822 without, for example, resolving symlinks.
823 ** You can now write frame unwinders in Python.
824 ** gdb.Type objects have a new method "optimized_out",
825 returning optimized out gdb.Value instance of this type.
826 ** gdb.Value objects have new methods "reference_value" and
827 "const_value" which return a reference to the value and a
828 "const" version of the value respectively.
832 maint print symbol-cache
833 Print the contents of the symbol cache.
835 maint print symbol-cache-statistics
836 Print statistics of symbol cache usage.
838 maint flush-symbol-cache
839 Flush the contents of the symbol cache.
843 Start branch trace recording using Branch Trace Store (BTS) format.
846 Evaluate expression by using the compiler and print result.
850 Explicit commands for enabling and disabling tui mode.
853 set mpx bound on i386 and amd64
854 Support for bound table investigation on Intel MPX enabled applications.
858 Start branch trace recording using Intel Processor Trace format.
861 Print information about branch tracing internals.
863 maint btrace packet-history
864 Print the raw branch tracing data.
866 maint btrace clear-packet-history
867 Discard the stored raw branch tracing data.
870 Discard all branch tracing data. It will be fetched and processed
871 anew by the next "record" command.
876 Renamed from "set debug dwarf2-die".
878 Renamed from "show debug dwarf2-die".
881 Renamed from "set debug dwarf2-read".
882 show debug dwarf-read
883 Renamed from "show debug dwarf2-read".
885 maint set dwarf always-disassemble
886 Renamed from "maint set dwarf2 always-disassemble".
887 maint show dwarf always-disassemble
888 Renamed from "maint show dwarf2 always-disassemble".
890 maint set dwarf max-cache-age
891 Renamed from "maint set dwarf2 max-cache-age".
892 maint show dwarf max-cache-age
893 Renamed from "maint show dwarf2 max-cache-age".
896 show debug dwarf-line
897 Control display of debugging info regarding DWARF line processing.
901 Set the maximum number of candidates to be considered during
902 completion. The default value is 200. This limit allows GDB
903 to avoid generating large completion lists, the computation of
904 which can cause the debugger to become temporarily unresponsive.
906 set history remove-duplicates
907 show history remove-duplicates
908 Control the removal of duplicate history entries.
910 maint set symbol-cache-size
911 maint show symbol-cache-size
912 Control the size of the symbol cache.
914 set|show record btrace bts buffer-size
915 Set and show the size of the ring buffer used for branch tracing in
917 The obtained size may differ from the requested size. Use "info
918 record" to see the obtained buffer size.
920 set debug linux-namespaces
921 show debug linux-namespaces
922 Control display of debugging info regarding Linux namespaces.
924 set|show record btrace pt buffer-size
925 Set and show the size of the ring buffer used for branch tracing in
926 Intel Processor Trace format.
927 The obtained size may differ from the requested size. Use "info
928 record" to see the obtained buffer size.
930 maint set|show btrace pt skip-pad
931 Set and show whether PAD packets are skipped when computing the
934 * The command 'thread apply all' can now support new option '-ascending'
935 to call its specified command for all threads in ascending order.
937 * Python/Guile scripting
939 ** GDB now supports auto-loading of Python/Guile scripts contained in the
940 special section named `.debug_gdb_scripts'.
944 qXfer:btrace-conf:read
945 Return the branch trace configuration for the current thread.
947 Qbtrace-conf:bts:size
948 Set the requested ring buffer size for branch tracing in BTS format.
951 Enable Intel Procesor Trace-based branch tracing for the current
952 process. The remote stub reports support for this packet to GDB's
956 Set the requested ring buffer size for branch tracing in Intel Processor
960 Indicates a memory breakpoint instruction was executed, irrespective
961 of whether it was GDB that planted the breakpoint or the breakpoint
962 is hardcoded in the program. This is required for correct non-stop
966 Indicates the target stopped for a hardware breakpoint. This is
967 required for correct non-stop mode operation.
970 Return information about files on the remote system.
973 Return the full absolute name of the file that was executed to
974 create a process running on the remote system.
977 Select the filesystem on which vFile: operations with filename
978 arguments will operate. This is required for GDB to be able to
979 access files on remote targets where the remote stub does not
980 share a common filesystem with the inferior(s).
983 Indicates that a fork system call was executed.
986 Indicates that a vfork system call was executed.
988 vforkdone stop reason
989 Indicates that a vfork child of the specified process has executed
990 an exec or exit, allowing the vfork parent to resume execution.
992 fork-events and vfork-events features in qSupported
993 The qSupported packet allows GDB to request support for fork and
994 vfork events using new 'gdbfeatures' fork-events and vfork-events,
995 and the qSupported response can contain the corresponding
996 'stubfeatures'. Set and show commands can be used to display
997 whether these features are enabled.
999 * Extended-remote fork events
1001 ** GDB now has support for fork events on extended-remote Linux
1002 targets. For targets with Linux kernels 2.5.60 and later, this
1003 enables follow-fork-mode and detach-on-fork for both fork and
1004 vfork, as well as fork and vfork catchpoints.
1006 * The info record command now shows the recording format and the
1007 branch tracing configuration for the current thread when using
1008 the btrace record target.
1009 For the BTS format, it shows the ring buffer size.
1011 * GDB now has support for DTrace USDT (Userland Static Defined
1012 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1014 * GDB now supports access to vector registers on S/390 GNU/Linux
1017 * Removed command line options
1019 -xdb HP-UX XDB compatibility mode.
1021 * Removed targets and native configurations
1023 HP/PA running HP-UX hppa*-*-hpux*
1024 Itanium running HP-UX ia64-*-hpux*
1026 * New configure options
1029 This configure option allows the user to build GDB with support for
1030 Intel Processor Trace (default: auto). This requires libipt.
1032 --with-libipt-prefix=PATH
1033 Specify the path to the version of libipt that GDB should use.
1034 $PATH/include should contain the intel-pt.h header and
1035 $PATH/lib should contain the libipt.so library.
1037 *** Changes in GDB 7.9.1
1041 ** Xmethods can now specify a result type.
1043 *** Changes in GDB 7.9
1045 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1049 ** You can now access frame registers from Python scripts.
1050 ** New attribute 'producer' for gdb.Symtab objects.
1051 ** gdb.Objfile objects have a new attribute "progspace",
1052 which is the gdb.Progspace object of the containing program space.
1053 ** gdb.Objfile objects have a new attribute "owner".
1054 ** gdb.Objfile objects have a new attribute "build_id",
1055 which is the build ID generated when the file was built.
1056 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1057 ** A new event "gdb.clear_objfiles" has been added, triggered when
1058 selecting a new file to debug.
1059 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1060 ** New function gdb.lookup_objfile.
1062 New events which are triggered when GDB modifies the state of the
1065 ** gdb.events.inferior_call_pre: Function call is about to be made.
1066 ** gdb.events.inferior_call_post: Function call has just been made.
1067 ** gdb.events.memory_changed: A memory location has been altered.
1068 ** gdb.events.register_changed: A register has been altered.
1070 * New Python-based convenience functions:
1072 ** $_caller_is(name [, number_of_frames])
1073 ** $_caller_matches(regexp [, number_of_frames])
1074 ** $_any_caller_is(name [, number_of_frames])
1075 ** $_any_caller_matches(regexp [, number_of_frames])
1077 * GDB now supports the compilation and injection of source code into
1078 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1079 to compile the source code to object code, and if successful, inject
1080 and execute that code within the current context of the inferior.
1081 Currently the C language is supported. The commands used to
1082 interface with this new feature are:
1084 compile code [-raw|-r] [--] [source code]
1085 compile file [-raw|-r] filename
1089 demangle [-l language] [--] name
1090 Demangle "name" in the specified language, or the current language
1091 if elided. This command is renamed from the "maint demangle" command.
1092 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1093 as "maint demangler-warning".
1095 queue-signal signal-name-or-number
1096 Queue a signal to be delivered to the thread when it is resumed.
1098 add-auto-load-scripts-directory directory
1099 Add entries to the list of directories from which to load auto-loaded
1102 maint print user-registers
1103 List all currently available "user" registers.
1105 compile code [-r|-raw] [--] [source code]
1106 Compile, inject, and execute in the inferior the executable object
1107 code produced by compiling the provided source code.
1109 compile file [-r|-raw] filename
1110 Compile and inject into the inferior the executable object code
1111 produced by compiling the source code stored in the filename
1114 * On resume, GDB now always passes the signal the program had stopped
1115 for to the thread the signal was sent to, even if the user changed
1116 threads before resuming. Previously GDB would often (but not
1117 always) deliver the signal to the thread that happens to be current
1120 * Conversely, the "signal" command now consistently delivers the
1121 requested signal to the current thread. GDB now asks for
1122 confirmation if the program had stopped for a signal and the user
1123 switched threads meanwhile.
1125 * "breakpoint always-inserted" modes "off" and "auto" merged.
1127 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1128 won't remove breakpoints from the target until all threads stop,
1129 even in non-stop mode. The "auto" mode has been removed, and "off"
1130 is now the default mode.
1134 set debug symbol-lookup
1135 show debug symbol-lookup
1136 Control display of debugging info regarding symbol lookup.
1140 ** The -list-thread-groups command outputs an exit-code field for
1141 inferiors that have exited.
1145 MIPS SDE mips*-sde*-elf*
1149 Support for these obsolete configurations has been removed.
1151 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1152 SGI Irix-5.x mips-*-irix5*
1153 SGI Irix-6.x mips-*-irix6*
1154 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1155 VAX running Ultrix vax-*-ultrix*
1157 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1158 and "assf"), have been removed. Use the "sharedlibrary" command, or
1159 its alias "share", instead.
1161 *** Changes in GDB 7.8
1163 * New command line options
1166 This is an alias for the --data-directory option.
1168 * GDB supports printing and modifying of variable length automatic arrays
1169 as specified in ISO C99.
1171 * The ARM simulator now supports instruction level tracing
1172 with or without disassembly.
1176 GDB now has support for scripting using Guile. Whether this is
1177 available is determined at configure time.
1178 Guile version 2.0 or greater is required.
1179 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1181 * New commands (for set/show, see "New options" below)
1185 Invoke CODE by passing it to the Guile interpreter.
1189 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1191 info auto-load guile-scripts [regexp]
1192 Print the list of automatically loaded Guile scripts.
1194 * The source command is now capable of sourcing Guile scripts.
1195 This feature is dependent on the debugger being built with Guile support.
1199 set print symbol-loading (off|brief|full)
1200 show print symbol-loading
1201 Control whether to print informational messages when loading symbol
1202 information for a file. The default is "full", but when debugging
1203 programs with large numbers of shared libraries the amount of output
1204 becomes less useful.
1206 set guile print-stack (none|message|full)
1207 show guile print-stack
1208 Show a stack trace when an error is encountered in a Guile script.
1210 set auto-load guile-scripts (on|off)
1211 show auto-load guile-scripts
1212 Control auto-loading of Guile script files.
1214 maint ada set ignore-descriptive-types (on|off)
1215 maint ada show ignore-descriptive-types
1216 Control whether the debugger should ignore descriptive types in Ada
1217 programs. The default is not to ignore the descriptive types. See
1218 the user manual for more details on descriptive types and the intended
1219 usage of this option.
1221 set auto-connect-native-target
1223 Control whether GDB is allowed to automatically connect to the
1224 native target for the run, attach, etc. commands when not connected
1225 to any target yet. See also "target native" below.
1227 set record btrace replay-memory-access (read-only|read-write)
1228 show record btrace replay-memory-access
1229 Control what memory accesses are allowed during replay.
1231 maint set target-async (on|off)
1232 maint show target-async
1233 This controls whether GDB targets operate in synchronous or
1234 asynchronous mode. Normally the default is asynchronous, if it is
1235 available; but this can be changed to more easily debug problems
1236 occurring only in synchronous mode.
1238 set mi-async (on|off)
1240 Control whether MI asynchronous mode is preferred. This supersedes
1241 "set target-async" of previous GDB versions.
1243 * "set target-async" is deprecated as a CLI option and is now an alias
1244 for "set mi-async" (only puts MI into async mode).
1246 * Background execution commands (e.g., "c&", "s&", etc.) are now
1247 possible ``out of the box'' if the target supports them. Previously
1248 the user would need to explicitly enable the possibility with the
1249 "set target-async on" command.
1251 * New features in the GDB remote stub, GDBserver
1253 ** New option --debug-format=option1[,option2,...] allows one to add
1254 additional text to each output. At present only timestamps
1255 are supported: --debug-format=timestamps.
1256 Timestamps can also be turned on with the
1257 "monitor set debug-format timestamps" command from GDB.
1259 * The 'record instruction-history' command now starts counting instructions
1260 at one. This also affects the instruction ranges reported by the
1261 'record function-call-history' command when given the /i modifier.
1263 * The command 'record function-call-history' supports a new modifier '/c' to
1264 indent the function names based on their call stack depth.
1265 The fields for the '/i' and '/l' modifier have been reordered.
1266 The source line range is now prefixed with 'at'.
1267 The instruction range is now prefixed with 'inst'.
1268 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1269 "record instruction-history" and "list" commands.
1271 * The ranges given as arguments to the 'record function-call-history' and
1272 'record instruction-history' commands are now inclusive.
1274 * The btrace record target now supports the 'record goto' command.
1275 For locations inside the execution trace, the back trace is computed
1276 based on the information stored in the execution trace.
1278 * The btrace record target supports limited reverse execution and replay.
1279 The target does not record data and therefore does not allow reading
1280 memory or registers.
1282 * The "catch syscall" command now works on s390*-linux* targets.
1284 * The "compare-sections" command is no longer specific to target
1285 remote. It now works with all targets.
1287 * All native targets are now consistently called "native".
1288 Consequently, the "target child", "target GNU", "target djgpp",
1289 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1290 commands have been replaced with "target native". The QNX/NTO port
1291 leaves the "procfs" target in place and adds a "native" target for
1292 consistency with other ports. The impact on users should be minimal
1293 as these commands previously either throwed an error, or were
1294 no-ops. The target's name is visible in the output of the following
1295 commands: "help target", "info target", "info files", "maint print
1298 * The "target native" command now connects to the native target. This
1299 can be used to launch native programs even when "set
1300 auto-connect-native-target" is set to off.
1302 * GDB now supports access to Intel MPX registers on GNU/Linux.
1304 * Support for Intel AVX-512 registers on GNU/Linux.
1305 Support displaying and modifying Intel AVX-512 registers
1306 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1308 * New remote packets
1310 qXfer:btrace:read's annex
1311 The qXfer:btrace:read packet supports a new annex 'delta' to read
1312 branch trace incrementally.
1316 ** Valid Python operations on gdb.Value objects representing
1317 structs/classes invoke the corresponding overloaded operators if
1319 ** New `Xmethods' feature in the Python API. Xmethods are
1320 additional methods or replacements for existing methods of a C++
1321 class. This feature is useful for those cases where a method
1322 defined in C++ source code could be inlined or optimized out by
1323 the compiler, making it unavailable to GDB.
1326 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1328 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1329 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1330 its alias "share", instead.
1332 * The commands "set remotebaud" and "show remotebaud" are no longer
1333 supported. Use "set serial baud" and "show serial baud" (respectively)
1338 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1339 target-async". The latter is left as a deprecated alias of the
1340 former for backward compatibility. If the target supports it,
1341 CLI background execution commands are now always possible by
1342 default, independently of whether the frontend stated a
1343 preference for asynchronous execution with "-gdb-set mi-async".
1344 Previously "-gdb-set target-async off" affected both MI execution
1345 commands and CLI execution commands.
1347 *** Changes in GDB 7.7
1349 * Improved support for process record-replay and reverse debugging on
1350 arm*-linux* targets. Support for thumb32 and syscall instruction
1351 recording has been added.
1353 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1355 * GDB now supports Fission DWP file format version 2.
1356 http://gcc.gnu.org/wiki/DebugFission
1358 * New convenience function "$_isvoid", to check whether an expression
1359 is void. A void expression is an expression where the type of the
1360 result is "void". For example, some convenience variables may be
1361 "void" when evaluated (e.g., "$_exitcode" before the execution of
1362 the program being debugged; or an undefined convenience variable).
1363 Another example, when calling a function whose return type is
1366 * The "maintenance print objfiles" command now takes an optional regexp.
1368 * The "catch syscall" command now works on arm*-linux* targets.
1370 * GDB now consistently shows "<not saved>" when printing values of
1371 registers the debug info indicates have not been saved in the frame
1372 and there's nowhere to retrieve them from
1373 (callee-saved/call-clobbered registers):
1378 (gdb) info registers rax
1381 Before, the former would print "<optimized out>", and the latter
1382 "*value not available*".
1384 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1389 ** Frame filters and frame decorators have been added.
1390 ** Temporary breakpoints are now supported.
1391 ** Line tables representation has been added.
1392 ** New attribute 'parent_type' for gdb.Field objects.
1393 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1394 ** New attribute 'name' for gdb.Type objects.
1398 Nios II ELF nios2*-*-elf
1399 Nios II GNU/Linux nios2*-*-linux
1400 Texas Instruments MSP430 msp430*-*-elf
1402 * Removed native configurations
1404 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1405 been removed. ELF variants of these configurations are kept supported.
1407 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1408 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1409 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1410 i[34567]86-*-openbsd3.[0-3]
1411 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1412 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1413 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1417 Like "catch throw", but catches a re-thrown exception.
1418 maint check-psymtabs
1419 Renamed from old "maint check-symtabs".
1421 Perform consistency checks on symtabs.
1422 maint expand-symtabs
1423 Expand symtabs matching an optional regexp.
1426 Display the details of GDB configure-time options.
1428 maint set|show per-command
1429 maint set|show per-command space
1430 maint set|show per-command time
1431 maint set|show per-command symtab
1432 Enable display of per-command gdb resource usage.
1434 remove-symbol-file FILENAME
1435 remove-symbol-file -a ADDRESS
1436 Remove a symbol file added via add-symbol-file. The file to remove
1437 can be identified by its filename or by an address that lies within
1438 the boundaries of this symbol file in memory.
1441 info exceptions REGEXP
1442 Display the list of Ada exceptions defined in the program being
1443 debugged. If provided, only the exceptions whose names match REGEXP
1448 set debug symfile off|on
1450 Control display of debugging info regarding reading symbol files and
1451 symbol tables within those files
1453 set print raw frame-arguments
1454 show print raw frame-arguments
1455 Set/show whether to print frame arguments in raw mode,
1456 disregarding any defined pretty-printers.
1458 set remote trace-status-packet
1459 show remote trace-status-packet
1460 Set/show the use of remote protocol qTStatus packet.
1464 Control display of debugging messages related to Nios II targets.
1468 Control whether target-assisted range stepping is enabled.
1470 set startup-with-shell
1471 show startup-with-shell
1472 Specifies whether Unix child processes are started via a shell or
1477 Use the target memory cache for accesses to the code segment. This
1478 improves performance of remote debugging (particularly disassembly).
1480 * You can now use a literal value 'unlimited' for options that
1481 interpret 0 or -1 as meaning "unlimited". E.g., "set
1482 trace-buffer-size unlimited" is now an alias for "set
1483 trace-buffer-size -1" and "set height unlimited" is now an alias for
1486 * The "set debug symtab-create" debugging option of GDB has been changed to
1487 accept a verbosity level. 0 means "off", 1 provides basic debugging
1488 output, and values of 2 or greater provides more verbose output.
1490 * New command-line options
1492 Display the details of GDB configure-time options.
1494 * The command 'tsave' can now support new option '-ctf' to save trace
1495 buffer in Common Trace Format.
1497 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1500 * GDB now implements the the C++ 'typeid' operator.
1502 * The new convenience variable $_exception holds the exception being
1503 thrown or caught at an exception-related catchpoint.
1505 * The exception-related catchpoints, like "catch throw", now accept a
1506 regular expression which can be used to filter exceptions by type.
1508 * The new convenience variable $_exitsignal is automatically set to
1509 the terminating signal number when the program being debugged dies
1510 due to an uncaught signal.
1514 ** All MI commands now accept an optional "--language" option.
1515 Support for this feature can be verified by using the "-list-features"
1516 command, which should contain "language-option".
1518 ** The new command -info-gdb-mi-command allows the user to determine
1519 whether a GDB/MI command is supported or not.
1521 ** The "^error" result record returned when trying to execute an undefined
1522 GDB/MI command now provides a variable named "code" whose content is the
1523 "undefined-command" error code. Support for this feature can be verified
1524 by using the "-list-features" command, which should contain
1525 "undefined-command-error-code".
1527 ** The -trace-save MI command can optionally save trace buffer in Common
1530 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1532 ** The command -data-list-register-values now accepts an optional
1533 "--skip-unavailable" option. When used, only the available registers
1536 ** The new command -trace-frame-collected dumps collected variables,
1537 computed expressions, tvars, memory and registers in a traceframe.
1539 ** The commands -stack-list-locals, -stack-list-arguments and
1540 -stack-list-variables now accept an option "--skip-unavailable".
1541 When used, only the available locals or arguments are displayed.
1543 ** The -exec-run command now accepts an optional "--start" option.
1544 When used, the command follows the same semantics as the "start"
1545 command, stopping the program's execution at the start of its
1546 main subprogram. Support for this feature can be verified using
1547 the "-list-features" command, which should contain
1548 "exec-run-start-option".
1550 ** The new commands -catch-assert and -catch-exceptions insert
1551 catchpoints stopping the program when Ada exceptions are raised.
1553 ** The new command -info-ada-exceptions provides the equivalent of
1554 the new "info exceptions" command.
1556 * New system-wide configuration scripts
1557 A GDB installation now provides scripts suitable for use as system-wide
1558 configuration scripts for the following systems:
1562 * GDB now supports target-assigned range stepping with remote targets.
1563 This improves the performance of stepping source lines by reducing
1564 the number of control packets from/to GDB. See "New remote packets"
1567 * GDB now understands the element 'tvar' in the XML traceframe info.
1568 It has the id of the collected trace state variables.
1570 * On S/390 targets that provide the transactional-execution feature,
1571 the program interruption transaction diagnostic block (TDB) is now
1572 represented as a number of additional "registers" in GDB.
1574 * New remote packets
1578 The vCont packet supports a new 'r' action, that tells the remote
1579 stub to step through an address range itself, without GDB
1580 involvemement at each single-step.
1582 qXfer:libraries-svr4:read's annex
1583 The previously unused annex of the qXfer:libraries-svr4:read packet
1584 is now used to support passing an argument list. The remote stub
1585 reports support for this argument list to GDB's qSupported query.
1586 The defined arguments are "start" and "prev", used to reduce work
1587 necessary for library list updating, resulting in significant
1590 * New features in the GDB remote stub, GDBserver
1592 ** GDBserver now supports target-assisted range stepping. Currently
1593 enabled on x86/x86_64 GNU/Linux targets.
1595 ** GDBserver now adds element 'tvar' in the XML in the reply to
1596 'qXfer:traceframe-info:read'. It has the id of the collected
1597 trace state variables.
1599 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1602 * New 'z' formatter for printing and examining memory, this displays the
1603 value as hexadecimal zero padded on the left to the size of the type.
1605 * GDB can now use Windows x64 unwinding data.
1607 * The "set remotebaud" command has been replaced by "set serial baud".
1608 Similarly, "show remotebaud" has been replaced by "show serial baud".
1609 The "set remotebaud" and "show remotebaud" commands are still available
1610 to provide backward compatibility with older versions of GDB.
1612 *** Changes in GDB 7.6
1614 * Target record has been renamed to record-full.
1615 Record/replay is now enabled with the "record full" command.
1616 This also affects settings that are associated with full record/replay
1617 that have been moved from "set/show record" to "set/show record full":
1619 set|show record full insn-number-max
1620 set|show record full stop-at-limit
1621 set|show record full memory-query
1623 * A new record target "record-btrace" has been added. The new target
1624 uses hardware support to record the control-flow of a process. It
1625 does not support replaying the execution, but it implements the
1626 below new commands for investigating the recorded execution log.
1627 This new recording method can be enabled using:
1631 The "record-btrace" target is only available on Intel Atom processors
1632 and requires a Linux kernel 2.6.32 or later.
1634 * Two new commands have been added for record/replay to give information
1635 about the recorded execution without having to replay the execution.
1636 The commands are only supported by "record btrace".
1638 record instruction-history prints the execution history at
1639 instruction granularity
1641 record function-call-history prints the execution history at
1642 function granularity
1644 * New native configurations
1646 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1647 FreeBSD/powerpc powerpc*-*-freebsd
1648 x86_64/Cygwin x86_64-*-cygwin*
1649 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1653 ARM AArch64 aarch64*-*-elf
1654 ARM AArch64 GNU/Linux aarch64*-*-linux
1655 Lynx 178 PowerPC powerpc-*-lynx*178
1656 x86_64/Cygwin x86_64-*-cygwin*
1657 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1659 * If the configured location of system.gdbinit file (as given by the
1660 --with-system-gdbinit option at configure time) is in the
1661 data-directory (as specified by --with-gdb-datadir at configure
1662 time) or in one of its subdirectories, then GDB will look for the
1663 system-wide init file in the directory specified by the
1664 --data-directory command-line option.
1666 * New command line options:
1668 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1669 other initialization files, unlike -nx which disables all of them.
1671 * Removed command line options
1673 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1676 * The 'ptype' and 'whatis' commands now accept an argument to control
1679 * 'info proc' now works on some core files.
1683 ** Vectors can be created with gdb.Type.vector.
1685 ** Python's atexit.register now works in GDB.
1687 ** Types can be pretty-printed via a Python API.
1689 ** Python 3 is now supported (in addition to Python 2.4 or later)
1691 ** New class gdb.Architecture exposes GDB's internal representation
1692 of architecture in the Python API.
1694 ** New method Frame.architecture returns the gdb.Architecture object
1695 corresponding to the frame's architecture.
1697 * New Python-based convenience functions:
1699 ** $_memeq(buf1, buf2, length)
1700 ** $_streq(str1, str2)
1702 ** $_regex(str, regex)
1704 * The 'cd' command now defaults to using '~' (the home directory) if not
1707 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1708 default for GCC since November 2000.
1710 * The command 'forward-search' can now be abbreviated as 'fo'.
1712 * The command 'info tracepoints' can now display 'installed on target'
1713 or 'not installed on target' for each non-pending location of tracepoint.
1715 * New configure options
1717 --enable-libmcheck/--disable-libmcheck
1718 By default, development versions are built with -lmcheck on hosts
1719 that support it, in order to help track memory corruption issues.
1720 Release versions, on the other hand, are built without -lmcheck
1721 by default. The --enable-libmcheck/--disable-libmcheck configure
1722 options allow the user to override that default.
1723 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1724 This configure option allows the user to build GDB with
1725 libbabeltrace using which GDB can read Common Trace Format data.
1727 * New commands (for set/show, see "New options" below)
1730 Catch signals. This is similar to "handle", but allows commands and
1731 conditions to be attached.
1734 List the BFDs known to GDB.
1736 python-interactive [command]
1738 Start a Python interactive prompt, or evaluate the optional command
1739 and print the result of expressions.
1742 "py" is a new alias for "python".
1744 enable type-printer [name]...
1745 disable type-printer [name]...
1746 Enable or disable type printers.
1750 ** For the Renesas Super-H architecture, the "regs" command has been removed
1751 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1756 set print type methods (on|off)
1757 show print type methods
1758 Control whether method declarations are displayed by "ptype".
1759 The default is to show them.
1761 set print type typedefs (on|off)
1762 show print type typedefs
1763 Control whether typedef definitions are displayed by "ptype".
1764 The default is to show them.
1766 set filename-display basename|relative|absolute
1767 show filename-display
1768 Control the way in which filenames is displayed.
1769 The default is "relative", which preserves previous behavior.
1771 set trace-buffer-size
1772 show trace-buffer-size
1773 Request target to change the size of trace buffer.
1775 set remote trace-buffer-size-packet auto|on|off
1776 show remote trace-buffer-size-packet
1777 Control the use of the remote protocol `QTBuffer:size' packet.
1781 Control display of debugging messages related to ARM AArch64.
1784 set debug coff-pe-read
1785 show debug coff-pe-read
1786 Control display of debugging messages related to reading of COFF/PE
1791 Control display of debugging messages related to Mach-O symbols
1794 set debug notification
1795 show debug notification
1796 Control display of debugging info for async remote notification.
1800 ** Command parameter changes are now notified using new async record
1801 "=cmd-param-changed".
1802 ** Trace frame changes caused by command "tfind" are now notified using
1803 new async record "=traceframe-changed".
1804 ** The creation, deletion and modification of trace state variables
1805 are now notified using new async records "=tsv-created",
1806 "=tsv-deleted" and "=tsv-modified".
1807 ** The start and stop of process record are now notified using new
1808 async record "=record-started" and "=record-stopped".
1809 ** Memory changes are now notified using new async record
1811 ** The data-disassemble command response will include a "fullname" field
1812 containing the absolute file name when source has been requested.
1813 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1814 command, to allow pattern filling of memory areas.
1815 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1816 library load/unload events.
1817 ** The response to breakpoint commands and breakpoint async records
1818 includes an "installed" field containing a boolean state about each
1819 non-pending tracepoint location is whether installed on target or not.
1820 ** Output of the "-trace-status" command includes a "trace-file" field
1821 containing the name of the trace file being examined. This field is
1822 optional, and only present when examining a trace file.
1823 ** The "fullname" field is now always present along with the "file" field,
1824 even if the file cannot be found by GDB.
1826 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1827 You must have the LZMA library available when configuring GDB for this
1828 feature to be enabled. For more information, see:
1829 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1831 * New remote packets
1834 Set the size of trace buffer. The remote stub reports support for this
1835 packet to gdb's qSupported query.
1838 Enable Branch Trace Store (BTS)-based branch tracing for the current
1839 thread. The remote stub reports support for this packet to gdb's
1843 Disable branch tracing for the current thread. The remote stub reports
1844 support for this packet to gdb's qSupported query.
1847 Read the traced branches for the current thread. The remote stub
1848 reports support for this packet to gdb's qSupported query.
1850 *** Changes in GDB 7.5
1852 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1853 for more x32 ABI info.
1855 * GDB now supports access to MIPS DSP registers on Linux targets.
1857 * GDB now supports debugging microMIPS binaries.
1859 * The "info os" command on GNU/Linux can now display information on
1860 several new classes of objects managed by the operating system:
1861 "info os procgroups" lists process groups
1862 "info os files" lists file descriptors
1863 "info os sockets" lists internet-domain sockets
1864 "info os shm" lists shared-memory regions
1865 "info os semaphores" lists semaphores
1866 "info os msg" lists message queues
1867 "info os modules" lists loaded kernel modules
1869 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1870 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1871 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1872 options and inspect the probe arguments using the new $_probe_arg family
1873 of convenience variables. You can obtain more information about SystemTap
1874 in <http://sourceware.org/systemtap/>.
1876 * GDB now supports reversible debugging on ARM, it allows you to
1877 debug basic ARM and THUMB instructions, and provides
1878 record/replay support.
1880 * The option "symbol-reloading" has been deleted as it is no longer used.
1884 ** GDB commands implemented in Python can now be put in command class
1887 ** The "maint set python print-stack on|off" is now deleted.
1889 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1890 apply "flag enum"-style pretty-printing to any enum.
1892 ** gdb.lookup_symbol can now work when there is no current frame.
1894 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1895 the source at which the symbol was defined.
1897 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1898 method 'value'. The former indicates whether the symbol needs a
1899 frame in order to compute its value, and the latter computes the
1902 ** A new method 'referenced_value' on gdb.Value objects which can
1903 dereference pointer as well as C++ reference values.
1905 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1906 which return the global and static blocks (as gdb.Block objects),
1907 of the underlying symbol table, respectively.
1909 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1910 object associated with a PC value.
1912 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1913 of the address range occupied by code for the current source line.
1915 * Go language support.
1916 GDB now supports debugging programs written in the Go programming
1919 * GDBserver now supports stdio connections.
1920 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1922 * The binary "gdbtui" can no longer be built or installed.
1923 Use "gdb -tui" instead.
1925 * GDB will now print "flag" enums specially. A flag enum is one where
1926 all the enumerator values have no bits in common when pairwise
1927 "and"ed. When printing a value whose type is a flag enum, GDB will
1928 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1929 (gdb) print (enum E) 3
1932 * The filename part of a linespec will now match trailing components
1933 of a source file name. For example, "break gcc/expr.c:1000" will
1934 now set a breakpoint in build/gcc/expr.c, but not
1935 build/libcpp/expr.c.
1937 * The "info proc" and "generate-core-file" commands will now also
1938 work on remote targets connected to GDBserver on Linux.
1940 * The command "info catch" has been removed. It has been disabled
1941 since December 2007.
1943 * The "catch exception" and "catch assert" commands now accept
1944 a condition at the end of the command, much like the "break"
1945 command does. For instance:
1947 (gdb) catch exception Constraint_Error if Barrier = True
1949 Previously, it was possible to add a condition to such catchpoints,
1950 but it had to be done as a second step, after the catchpoint had been
1951 created, using the "condition" command.
1953 * The "info static-tracepoint-marker" command will now also work on
1954 native Linux targets with in-process agent.
1956 * GDB can now set breakpoints on inlined functions.
1958 * The .gdb_index section has been updated to include symbols for
1959 inlined functions. GDB will ignore older .gdb_index sections by
1960 default, which could cause symbol files to be loaded more slowly
1961 until their .gdb_index sections can be recreated. The new command
1962 "set use-deprecated-index-sections on" will cause GDB to use any older
1963 .gdb_index sections it finds. This will restore performance, but the
1964 ability to set breakpoints on inlined functions will be lost in symbol
1965 files with older .gdb_index sections.
1967 The .gdb_index section has also been updated to record more information
1968 about each symbol. This speeds up the "info variables", "info functions"
1969 and "info types" commands when used with programs having the .gdb_index
1970 section, as well as speeding up debugging with shared libraries using
1971 the .gdb_index section.
1973 * Ada support for GDB/MI Variable Objects has been added.
1975 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1980 ** New command -info-os is the MI equivalent of "info os".
1982 ** Output logs ("set logging" and related) now include MI output.
1986 ** "set use-deprecated-index-sections on|off"
1987 "show use-deprecated-index-sections on|off"
1988 Controls the use of deprecated .gdb_index sections.
1990 ** "catch load" and "catch unload" can be used to stop when a shared
1991 library is loaded or unloaded, respectively.
1993 ** "enable count" can be used to auto-disable a breakpoint after
1996 ** "info vtbl" can be used to show the virtual method tables for
1997 C++ and Java objects.
1999 ** "explore" and its sub commands "explore value" and "explore type"
2000 can be used to recursively explore values and types of
2001 expressions. These commands are available only if GDB is
2002 configured with '--with-python'.
2004 ** "info auto-load" shows status of all kinds of auto-loaded files,
2005 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2006 sequences of commands files, "info auto-load python-scripts"
2007 shows status of auto-loading Python script files,
2008 "info auto-load local-gdbinit" shows status of loading init file
2009 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2010 status of inferior specific thread debugging shared library loading.
2012 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2013 and "show auto-load-scripts" commands have been deprecated, use their
2014 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2015 and "show auto-load python-scripts" counterparts instead.
2017 ** "dprintf location,format,args..." creates a dynamic printf, which
2018 is basically a breakpoint that does a printf and immediately
2019 resumes your program's execution, so it is like a printf that you
2020 can insert dynamically at runtime instead of at compiletime.
2022 ** "set print symbol"
2024 Controls whether GDB attempts to display the symbol, if any,
2025 corresponding to addresses it prints. This defaults to "on", but
2026 you can set it to "off" to restore GDB's previous behavior.
2028 * Deprecated commands
2030 ** For the Renesas Super-H architecture, the "regs" command has been
2031 deprecated, and "info all-registers" should be used instead.
2035 Renesas RL78 rl78-*-elf
2036 HP OpenVMS ia64 ia64-hp-openvms*
2038 * GDBserver supports evaluation of breakpoint conditions. When
2039 support is advertised by GDBserver, GDB may be told to send the
2040 breakpoint conditions in bytecode form to GDBserver. GDBserver
2041 will only report the breakpoint trigger to GDB when its condition
2046 set mips compression
2047 show mips compression
2048 Select the compressed ISA encoding used in functions that have no symbol
2049 information available. The encoding can be set to either of:
2052 and is updated automatically from ELF file flags if available.
2054 set breakpoint condition-evaluation
2055 show breakpoint condition-evaluation
2056 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2057 GDBserver ("target"). Default option "auto" chooses the most efficient
2059 This option can improve debugger efficiency depending on the speed of the
2063 Disable auto-loading globally.
2066 Show auto-loading setting of all kinds of auto-loaded files.
2068 set auto-load gdb-scripts on|off
2069 show auto-load gdb-scripts
2070 Control auto-loading of GDB canned sequences of commands files.
2072 set auto-load python-scripts on|off
2073 show auto-load python-scripts
2074 Control auto-loading of Python script files.
2076 set auto-load local-gdbinit on|off
2077 show auto-load local-gdbinit
2078 Control loading of init file (.gdbinit) from current directory.
2080 set auto-load libthread-db on|off
2081 show auto-load libthread-db
2082 Control auto-loading of inferior specific thread debugging shared library.
2084 set auto-load scripts-directory <dir1>[:<dir2>...]
2085 show auto-load scripts-directory
2086 Set a list of directories from which to load auto-loaded scripts.
2087 Automatically loaded Python scripts and GDB scripts are located in one
2088 of the directories listed by this option.
2089 The delimiter (':' above) may differ according to the host platform.
2091 set auto-load safe-path <dir1>[:<dir2>...]
2092 show auto-load safe-path
2093 Set a list of directories from which it is safe to auto-load files.
2094 The delimiter (':' above) may differ according to the host platform.
2096 set debug auto-load on|off
2097 show debug auto-load
2098 Control display of debugging info for auto-loading the files above.
2100 set dprintf-style gdb|call|agent
2102 Control the way in which a dynamic printf is performed; "gdb"
2103 requests a GDB printf command, while "call" causes dprintf to call a
2104 function in the inferior. "agent" requests that the target agent
2105 (such as GDBserver) do the printing.
2107 set dprintf-function <expr>
2108 show dprintf-function
2109 set dprintf-channel <expr>
2110 show dprintf-channel
2111 Set the function and optional first argument to the call when using
2112 the "call" style of dynamic printf.
2114 set disconnected-dprintf on|off
2115 show disconnected-dprintf
2116 Control whether agent-style dynamic printfs continue to be in effect
2117 after GDB disconnects.
2119 * New configure options
2121 --with-auto-load-dir
2122 Configure default value for the 'set auto-load scripts-directory'
2123 setting above. It defaults to '$debugdir:$datadir/auto-load',
2124 $debugdir representing global debugging info directories (available
2125 via 'show debug-file-directory') and $datadir representing GDB's data
2126 directory (available via 'show data-directory').
2128 --with-auto-load-safe-path
2129 Configure default value for the 'set auto-load safe-path' setting
2130 above. It defaults to the --with-auto-load-dir setting.
2132 --without-auto-load-safe-path
2133 Set 'set auto-load safe-path' to '/', effectively disabling this
2136 * New remote packets
2138 z0/z1 conditional breakpoints extension
2140 The z0/z1 breakpoint insertion packets have been extended to carry
2141 a list of conditional expressions over to the remote stub depending on the
2142 condition evaluation mode. The use of this extension can be controlled
2143 via the "set remote conditional-breakpoints-packet" command.
2147 Specify the signals which the remote stub may pass to the debugged
2148 program without GDB involvement.
2150 * New command line options
2152 --init-command=FILE, -ix Like --command, -x but execute it
2153 before loading inferior.
2154 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2155 execute it before loading inferior.
2157 *** Changes in GDB 7.4
2159 * GDB now handles ambiguous linespecs more consistently; the existing
2160 FILE:LINE support has been expanded to other types of linespecs. A
2161 breakpoint will now be set on all matching locations in all
2162 inferiors, and locations will be added or removed according to
2165 * GDB now allows you to skip uninteresting functions and files when
2166 stepping with the "skip function" and "skip file" commands.
2168 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2169 and "show remote hardware-watchpoint-length-limit". These allows to
2170 set or show the maximum length limit (in bytes) of a remote
2171 target hardware watchpoint.
2173 This allows e.g. to use "unlimited" hardware watchpoints with the
2174 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2175 watchpoints are slower than real hardware watchpoints but are
2176 significantly faster than gdb software watchpoints.
2180 ** The register_pretty_printer function in module gdb.printing now takes
2181 an optional `replace' argument. If True, the new printer replaces any
2184 ** The "maint set python print-stack on|off" command has been
2185 deprecated and will be deleted in GDB 7.5.
2186 A new command: "set python print-stack none|full|message" has
2187 replaced it. Additionally, the default for "print-stack" is
2188 now "message", which just prints the error message without
2191 ** A prompt substitution hook (prompt_hook) is now available to the
2194 ** A new Python module, gdb.prompt has been added to the GDB Python
2195 modules library. This module provides functionality for
2196 escape sequences in prompts (used by set/show
2197 extended-prompt). These escape sequences are replaced by their
2198 corresponding value.
2200 ** Python commands and convenience-functions located in
2201 'data-directory'/python/gdb/command and
2202 'data-directory'/python/gdb/function are now automatically loaded
2205 ** Blocks now provide four new attributes. global_block and
2206 static_block will return the global and static blocks
2207 respectively. is_static and is_global are boolean attributes
2208 that indicate if the block is one of those two types.
2210 ** Symbols now provide the "type" attribute, the type of the symbol.
2212 ** The "gdb.breakpoint" function has been deprecated in favor of
2215 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2216 of a function. This class is based on the "finish" command
2217 available in the CLI.
2219 ** Type objects for struct and union types now allow access to
2220 the fields using standard Python dictionary (mapping) methods.
2221 For example, "some_type['myfield']" now works, as does
2222 "some_type.items()".
2224 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2227 ** A new function, "deep_items" has been added to the gdb.types
2228 module in the GDB Python modules library. This function returns
2229 an iterator over the fields of a struct or union type. Unlike
2230 the standard Python "iteritems" method, it will recursively traverse
2231 any anonymous fields.
2235 ** "*stopped" events can report several new "reason"s, such as
2238 ** Breakpoint changes are now notified using new async records, like
2239 "=breakpoint-modified".
2241 ** New command -ada-task-info.
2243 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2244 $sdir specifies the default system locations of shared libraries.
2245 $pdir specifies the directory where the libpthread used by the application
2248 GDB no longer looks in $sdir and $pdir after it has searched the directories
2249 mentioned in libthread-db-search-path. If you want to search those
2250 directories, they must be specified in libthread-db-search-path.
2251 The default value of libthread-db-search-path on GNU/Linux and Solaris
2252 systems is now "$sdir:$pdir".
2254 $pdir is not supported by gdbserver, it is currently ignored.
2255 $sdir is supported by gdbserver.
2257 * New configure option --with-iconv-bin.
2258 When using the internationalization support like the one in the GNU C
2259 library, GDB will invoke the "iconv" program to get a list of supported
2260 character sets. If this program lives in a non-standard location, one can
2261 use this option to specify where to find it.
2263 * When natively debugging programs on PowerPC BookE processors running
2264 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2265 watchpoints, which specify a mask in addition to an address to watch.
2266 The mask specifies that some bits of an address (the bits which are
2267 reset in the mask) should be ignored when matching the address accessed
2268 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2269 section in the user manual for more details.
2271 * The new option --once causes GDBserver to stop listening for connections once
2272 the first connection is made. The listening port used by GDBserver will
2273 become available after that.
2275 * New commands "info macros" and "alias" have been added.
2277 * New function parameters suffix @entry specifies value of function parameter
2278 at the time the function got called. Entry values are available only since
2284 "!" is now an alias of the "shell" command.
2285 Note that no space is needed between "!" and SHELL COMMAND.
2289 watch EXPRESSION mask MASK_VALUE
2290 The watch command now supports the mask argument which allows creation
2291 of masked watchpoints, if the current architecture supports this feature.
2293 info auto-load-scripts [REGEXP]
2294 This command was formerly named "maintenance print section-scripts".
2295 It is now generally useful and is no longer a maintenance-only command.
2297 info macro [-all] [--] MACRO
2298 The info macro command has new options `-all' and `--'. The first for
2299 printing all definitions of a macro. The second for explicitly specifying
2300 the end of arguments and the beginning of the macro name in case the macro
2301 name starts with a hyphen.
2303 collect[/s] EXPRESSIONS
2304 The tracepoint collect command now takes an optional modifier "/s"
2305 that directs it to dereference pointer-to-character types and
2306 collect the bytes of memory up to a zero byte. The behavior is
2307 similar to what you see when you use the regular print command on a
2308 string. An optional integer following the "/s" sets a bound on the
2309 number of bytes that will be collected.
2312 The trace start command now interprets any supplied arguments as a
2313 note to be recorded with the trace run, with an effect similar to
2314 setting the variable trace-notes.
2317 The trace stop command now interprets any arguments as a note to be
2318 mentioned along with the tstatus report that the trace was stopped
2319 with a command. The effect is similar to setting the variable
2322 * Tracepoints can now be enabled and disabled at any time after a trace
2323 experiment has been started using the standard "enable" and "disable"
2324 commands. It is now possible to start a trace experiment with no enabled
2325 tracepoints; GDB will display a warning, but will allow the experiment to
2326 begin, assuming that tracepoints will be enabled as needed while the trace
2329 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2330 locations with 4-byte instructions, when they were previously
2331 limited to locations with instructions of 5 bytes or longer.
2335 set debug dwarf2-read
2336 show debug dwarf2-read
2337 Turns on or off display of debugging messages related to reading
2338 DWARF debug info. The default is off.
2340 set debug symtab-create
2341 show debug symtab-create
2342 Turns on or off display of debugging messages related to symbol table
2343 creation. The default is off.
2346 show extended-prompt
2347 Set the GDB prompt, and allow escape sequences to be inserted to
2348 display miscellaneous information (see 'help set extended-prompt'
2349 for the list of sequences). This prompt (and any information
2350 accessed through the escape sequences) is updated every time the
2351 prompt is displayed.
2353 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2354 show print entry-values
2355 Set printing of frame argument values at function entry. In some cases
2356 GDB can determine the value of function argument which was passed by the
2357 function caller, even if the value was modified inside the called function.
2359 set debug entry-values
2360 show debug entry-values
2361 Control display of debugging info for determining frame argument values at
2362 function entry and virtual tail call frames.
2364 set basenames-may-differ
2365 show basenames-may-differ
2366 Set whether a source file may have multiple base names.
2367 (A "base name" is the name of a file with the directory part removed.
2368 Example: The base name of "/home/user/hello.c" is "hello.c".)
2369 If set, GDB will canonicalize file names (e.g., expand symlinks)
2370 before comparing them. Canonicalization is an expensive operation,
2371 but it allows the same file be known by more than one base name.
2372 If not set (the default), all source files are assumed to have just
2373 one base name, and gdb will do file name comparisons more efficiently.
2379 Set a user name and notes for the current and any future trace runs.
2380 This is useful for long-running and/or disconnected traces, to
2381 inform others (or yourself) as to who is running the trace, supply
2382 contact information, or otherwise explain what is going on.
2384 set trace-stop-notes
2385 show trace-stop-notes
2386 Set a note attached to the trace run, that is displayed when the
2387 trace has been stopped by a tstop command. This is useful for
2388 instance as an explanation, if you are stopping a trace run that was
2389 started by someone else.
2391 * New remote packets
2395 Dynamically enable a tracepoint in a started trace experiment.
2399 Dynamically disable a tracepoint in a started trace experiment.
2403 Set the user and notes of the trace run.
2407 Query the current status of a tracepoint.
2411 Query the minimum length of instruction at which a fast tracepoint may
2414 * Dcache size (number of lines) and line-size are now runtime-configurable
2415 via "set dcache line" and "set dcache line-size" commands.
2419 Texas Instruments TMS320C6x tic6x-*-*
2423 Renesas RL78 rl78-*-elf
2425 *** Changes in GDB 7.3.1
2427 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2429 *** Changes in GDB 7.3
2431 * GDB has a new command: "thread find [REGEXP]".
2432 It finds the thread id whose name, target id, or thread extra info
2433 matches the given regular expression.
2435 * The "catch syscall" command now works on mips*-linux* targets.
2437 * The -data-disassemble MI command now supports modes 2 and 3 for
2438 dumping the instruction opcodes.
2440 * New command line options
2442 -data-directory DIR Specify DIR as the "data-directory".
2443 This is mostly for testing purposes.
2445 * The "maint set python auto-load on|off" command has been renamed to
2446 "set auto-load-scripts on|off".
2448 * GDB has a new command: "set directories".
2449 It is like the "dir" command except that it replaces the
2450 source path list instead of augmenting it.
2452 * GDB now understands thread names.
2454 On GNU/Linux, "info threads" will display the thread name as set by
2455 prctl or pthread_setname_np.
2457 There is also a new command, "thread name", which can be used to
2458 assign a name internally for GDB to display.
2461 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2462 has been integrated into GDB.
2466 ** The function gdb.Write now accepts an optional keyword 'stream'.
2467 This keyword, when provided, will direct the output to either
2468 stdout, stderr, or GDB's logging output.
2470 ** Parameters can now be be sub-classed in Python, and in particular
2471 you may implement the get_set_doc and get_show_doc functions.
2472 This improves how Parameter set/show documentation is processed
2473 and allows for more dynamic content.
2475 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2476 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2477 have an is_valid method.
2479 ** Breakpoints can now be sub-classed in Python, and in particular
2480 you may implement a 'stop' function that is executed each time
2481 the inferior reaches that breakpoint.
2483 ** New function gdb.lookup_global_symbol looks up a global symbol.
2485 ** GDB values in Python are now callable if the value represents a
2486 function. For example, if 'some_value' represents a function that
2487 takes two integer parameters and returns a value, you can call
2488 that function like so:
2490 result = some_value (10,20)
2492 ** Module gdb.types has been added.
2493 It contains a collection of utilities for working with gdb.Types objects:
2494 get_basic_type, has_field, make_enum_dict.
2496 ** Module gdb.printing has been added.
2497 It contains utilities for writing and registering pretty-printers.
2498 New classes: PrettyPrinter, SubPrettyPrinter,
2499 RegexpCollectionPrettyPrinter.
2500 New function: register_pretty_printer.
2502 ** New commands "info pretty-printers", "enable pretty-printer" and
2503 "disable pretty-printer" have been added.
2505 ** gdb.parameter("directories") is now available.
2507 ** New function gdb.newest_frame returns the newest frame in the
2510 ** The gdb.InferiorThread class has a new "name" attribute. This
2511 holds the thread's name.
2513 ** Python Support for Inferior events.
2514 Python scripts can add observers to be notified of events
2515 occurring in the process being debugged.
2516 The following events are currently supported:
2517 - gdb.events.cont Continue event.
2518 - gdb.events.exited Inferior exited event.
2519 - gdb.events.stop Signal received, and Breakpoint hit events.
2523 ** GDB now puts template parameters in scope when debugging in an
2524 instantiation. For example, if you have:
2526 template<int X> int func (void) { return X; }
2528 then if you step into func<5>, "print X" will show "5". This
2529 feature requires proper debuginfo support from the compiler; it
2530 was added to GCC 4.5.
2532 ** The motion commands "next", "finish", "until", and "advance" now
2533 work better when exceptions are thrown. In particular, GDB will
2534 no longer lose control of the inferior; instead, the GDB will
2535 stop the inferior at the point at which the exception is caught.
2536 This functionality requires a change in the exception handling
2537 code that was introduced in GCC 4.5.
2539 * GDB now follows GCC's rules on accessing volatile objects when
2540 reading or writing target state during expression evaluation.
2541 One notable difference to prior behavior is that "print x = 0"
2542 no longer generates a read of x; the value of the assignment is
2543 now always taken directly from the value being assigned.
2545 * GDB now has some support for using labels in the program's source in
2546 linespecs. For instance, you can use "advance label" to continue
2547 execution to a label.
2549 * GDB now has support for reading and writing a new .gdb_index
2550 section. This section holds a fast index of DWARF debugging
2551 information and can be used to greatly speed up GDB startup and
2552 operation. See the documentation for `save gdb-index' for details.
2554 * The "watch" command now accepts an optional "-location" argument.
2555 When used, this causes GDB to watch the memory referred to by the
2556 expression. Such a watchpoint is never deleted due to it going out
2559 * GDB now supports thread debugging of core dumps on GNU/Linux.
2561 GDB now activates thread debugging using the libthread_db library
2562 when debugging GNU/Linux core dumps, similarly to when debugging
2563 live processes. As a result, when debugging a core dump file, GDB
2564 is now able to display pthread_t ids of threads. For example, "info
2565 threads" shows the same output as when debugging the process when it
2566 was live. In earlier releases, you'd see something like this:
2569 * 1 LWP 6780 main () at main.c:10
2571 While now you see this:
2574 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2576 It is also now possible to inspect TLS variables when debugging core
2579 When debugging a core dump generated on a machine other than the one
2580 used to run GDB, you may need to point GDB at the correct
2581 libthread_db library with the "set libthread-db-search-path"
2582 command. See the user manual for more details on this command.
2584 * When natively debugging programs on PowerPC BookE processors running
2585 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2586 which stop execution of the inferior whenever it executes an instruction
2587 at any address within the specified range. See the "PowerPC Embedded"
2588 section in the user manual for more details.
2590 * New features in the GDB remote stub, GDBserver
2592 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2593 and i686 LynxOS (version 5.x).
2595 ** GDBserver is now supported on Blackfin Linux.
2597 * New native configurations
2599 ia64 HP-UX ia64-*-hpux*
2603 Analog Devices, Inc. Blackfin Processor bfin-*
2605 * Ada task switching is now supported on sparc-elf targets when
2606 debugging a program using the Ravenscar Profile. For more information,
2607 see the "Tasking Support when using the Ravenscar Profile" section
2608 in the GDB user manual.
2610 * Guile support was removed.
2612 * New features in the GNU simulator
2614 ** The --map-info flag lists all known core mappings.
2616 ** CFI flashes may be simulated via the "cfi" device.
2618 *** Changes in GDB 7.2
2620 * Shared library support for remote targets by default
2622 When GDB is configured for a generic, non-OS specific target, like
2623 for example, --target=arm-eabi or one of the many *-*-elf targets,
2624 GDB now queries remote stubs for loaded shared libraries using the
2625 `qXfer:libraries:read' packet. Previously, shared library support
2626 was always disabled for such configurations.
2630 ** Argument Dependent Lookup (ADL)
2632 In C++ ADL lookup directs function search to the namespaces of its
2633 arguments even if the namespace has not been imported.
2643 Here the compiler will search for `foo' in the namespace of 'b'
2644 and find A::foo. GDB now supports this. This construct is commonly
2645 used in the Standard Template Library for operators.
2647 ** Improved User Defined Operator Support
2649 In addition to member operators, GDB now supports lookup of operators
2650 defined in a namespace and imported with a `using' directive, operators
2651 defined in the global scope, operators imported implicitly from an
2652 anonymous namespace, and the ADL operators mentioned in the previous
2654 GDB now also supports proper overload resolution for all the previously
2655 mentioned flavors of operators.
2657 ** static const class members
2659 Printing of static const class members that are initialized in the
2660 class definition has been fixed.
2662 * Windows Thread Information Block access.
2664 On Windows targets, GDB now supports displaying the Windows Thread
2665 Information Block (TIB) structure. This structure is visible either
2666 by using the new command `info w32 thread-information-block' or, by
2667 dereferencing the new convenience variable named `$_tlb', a
2668 thread-specific pointer to the TIB. This feature is also supported
2669 when remote debugging using GDBserver.
2671 * Static tracepoints
2673 Static tracepoints are calls in the user program into a tracing
2674 library. One such library is a port of the LTTng kernel tracer to
2675 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2676 When debugging with GDBserver, GDB now supports combining the GDB
2677 tracepoint machinery with such libraries. For example: the user can
2678 use GDB to probe a static tracepoint marker (a call from the user
2679 program into the tracing library) with the new "strace" command (see
2680 "New commands" below). This creates a "static tracepoint" in the
2681 breakpoint list, that can be manipulated with the same feature set
2682 as fast and regular tracepoints. E.g., collect registers, local and
2683 global variables, collect trace state variables, and define
2684 tracepoint conditions. In addition, the user can collect extra
2685 static tracepoint marker specific data, by collecting the new
2686 $_sdata internal variable. When analyzing the trace buffer, you can
2687 inspect $_sdata like any other variable available to GDB. For more
2688 information, see the "Tracepoints" chapter in GDB user manual. New
2689 remote packets have been defined to support static tracepoints, see
2690 the "New remote packets" section below.
2692 * Better reconstruction of tracepoints after disconnected tracing
2694 GDB will attempt to download the original source form of tracepoint
2695 definitions when starting a trace run, and then will upload these
2696 upon reconnection to the target, resulting in a more accurate
2697 reconstruction of the tracepoints that are in use on the target.
2701 You can now exercise direct control over the ways that GDB can
2702 affect your program. For instance, you can disallow the setting of
2703 breakpoints, so that the program can run continuously (assuming
2704 non-stop mode). In addition, the "observer" variable is available
2705 to switch all of the different controls; in observer mode, GDB
2706 cannot affect the target's behavior at all, which is useful for
2707 tasks like diagnosing live systems in the field.
2709 * The new convenience variable $_thread holds the number of the
2712 * New remote packets
2716 Return the address of the Windows Thread Information Block of a given thread.
2720 In response to several of the tracepoint packets, the target may now
2721 also respond with a number of intermediate `qRelocInsn' request
2722 packets before the final result packet, to have GDB handle
2723 relocating an instruction to execute at a different address. This
2724 is particularly useful for stubs that support fast tracepoints. GDB
2725 reports support for this feature in the qSupported packet.
2729 List static tracepoint markers in the target program.
2733 List static tracepoint markers at a given address in the target
2736 qXfer:statictrace:read
2738 Read the static trace data collected (by a `collect $_sdata'
2739 tracepoint action). The remote stub reports support for this packet
2740 to gdb's qSupported query.
2744 Send the current settings of GDB's permission flags.
2748 Send part of the source (textual) form of a tracepoint definition,
2749 which includes location, conditional, and action list.
2751 * The source command now accepts a -s option to force searching for the
2752 script in the source search path even if the script name specifies
2755 * New features in the GDB remote stub, GDBserver
2757 - GDBserver now support tracepoints (including fast tracepoints, and
2758 static tracepoints). The feature is currently supported by the
2759 i386-linux and amd64-linux builds. See the "Tracepoints support
2760 in gdbserver" section in the manual for more information.
2762 GDBserver JIT compiles the tracepoint's conditional agent
2763 expression bytecode into native code whenever possible for low
2764 overhead dynamic tracepoints conditionals. For such tracepoints,
2765 an expression that examines program state is evaluated when the
2766 tracepoint is reached, in order to determine whether to capture
2767 trace data. If the condition is simple and false, processing the
2768 tracepoint finishes very quickly and no data is gathered.
2770 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2771 for static tracepoints support.
2773 - GDBserver now supports x86_64 Windows 64-bit debugging.
2775 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2776 it understands register description.
2778 * The --batch flag now disables pagination and queries.
2780 * X86 general purpose registers
2782 GDB now supports reading/writing byte, word and double-word x86
2783 general purpose registers directly. This means you can use, say,
2784 $ah or $ax to refer, respectively, to the byte register AH and
2785 16-bit word register AX that are actually portions of the 32-bit
2786 register EAX or 64-bit register RAX.
2788 * The `commands' command now accepts a range of breakpoints to modify.
2789 A plain `commands' following a command that creates multiple
2790 breakpoints affects all the breakpoints set by that command. This
2791 applies to breakpoints set by `rbreak', and also applies when a
2792 single `break' command creates multiple breakpoints (e.g.,
2793 breakpoints on overloaded c++ functions).
2795 * The `rbreak' command now accepts a filename specification as part of
2796 its argument, limiting the functions selected by the regex to those
2797 in the specified file.
2799 * Support for remote debugging Windows and SymbianOS shared libraries
2800 from Unix hosts has been improved. Non Windows GDB builds now can
2801 understand target reported file names that follow MS-DOS based file
2802 system semantics, such as file names that include drive letters and
2803 use the backslash character as directory separator. This makes it
2804 possible to transparently use the "set sysroot" and "set
2805 solib-search-path" on Unix hosts to point as host copies of the
2806 target's shared libraries. See the new command "set
2807 target-file-system-kind" described below, and the "Commands to
2808 specify files" section in the user manual for more information.
2812 eval template, expressions...
2813 Convert the values of one or more expressions under the control
2814 of the string template to a command line, and call it.
2816 set target-file-system-kind unix|dos-based|auto
2817 show target-file-system-kind
2818 Set or show the assumed file system kind for target reported file
2821 save breakpoints <filename>
2822 Save all current breakpoint definitions to a file suitable for use
2823 in a later debugging session. To read the saved breakpoint
2824 definitions, use the `source' command.
2826 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2829 info static-tracepoint-markers
2830 Display information about static tracepoint markers in the target.
2832 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2833 Define a static tracepoint by probing a marker at the given
2834 function, line, address, or marker ID.
2838 Enable and disable observer mode.
2840 set may-write-registers on|off
2841 set may-write-memory on|off
2842 set may-insert-breakpoints on|off
2843 set may-insert-tracepoints on|off
2844 set may-insert-fast-tracepoints on|off
2845 set may-interrupt on|off
2846 Set individual permissions for GDB effects on the target. Note that
2847 some of these settings can have undesirable or surprising
2848 consequences, particularly when changed in the middle of a session.
2849 For instance, disabling the writing of memory can prevent
2850 breakpoints from being inserted, cause single-stepping to fail, or
2851 even crash your program, if you disable after breakpoints have been
2852 inserted. However, GDB should not crash.
2854 set record memory-query on|off
2855 show record memory-query
2856 Control whether to stop the inferior if memory changes caused
2857 by an instruction cannot be recorded.
2862 The disassemble command now supports "start,+length" form of two arguments.
2866 ** GDB now provides a new directory location, called the python directory,
2867 where Python scripts written for GDB can be installed. The location
2868 of that directory is <data-directory>/python, where <data-directory>
2869 is the GDB data directory. For more details, see section `Scripting
2870 GDB using Python' in the manual.
2872 ** The GDB Python API now has access to breakpoints, symbols, symbol
2873 tables, program spaces, inferiors, threads and frame's code blocks.
2874 Additionally, GDB Parameters can now be created from the API, and
2875 manipulated via set/show in the CLI.
2877 ** New functions gdb.target_charset, gdb.target_wide_charset,
2878 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2880 ** New exception gdb.GdbError.
2882 ** Pretty-printers are now also looked up in the current program space.
2884 ** Pretty-printers can now be individually enabled and disabled.
2886 ** GDB now looks for names of Python scripts to auto-load in a
2887 special section named `.debug_gdb_scripts', in addition to looking
2888 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2890 * Tracepoint actions were unified with breakpoint commands. In particular,
2891 there are no longer differences in "info break" output for breakpoints and
2892 tracepoints and the "commands" command can be used for both tracepoints and
2893 regular breakpoints.
2897 ARM Symbian arm*-*-symbianelf*
2899 * D language support.
2900 GDB now supports debugging programs written in the D programming
2903 * GDB now supports the extended ptrace interface for PowerPC which is
2904 available since Linux kernel version 2.6.34. This automatically enables
2905 any hardware breakpoints and additional hardware watchpoints available in
2906 the processor. The old ptrace interface exposes just one hardware
2907 watchpoint and no hardware breakpoints.
2909 * GDB is now able to use the Data Value Compare (DVC) register available on
2910 embedded PowerPC processors to implement in hardware simple watchpoint
2911 conditions of the form:
2913 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2915 This works in native GDB running on Linux kernels with the extended ptrace
2916 interface mentioned above.
2918 *** Changes in GDB 7.1
2922 ** Namespace Support
2924 GDB now supports importing of namespaces in C++. This enables the
2925 user to inspect variables from imported namespaces. Support for
2926 namepace aliasing has also been added. So, if a namespace is
2927 aliased in the current scope (e.g. namepace C=A; ) the user can
2928 print variables using the alias (e.g. (gdb) print C::x).
2932 All known bugs relating to the printing of virtual base class were
2933 fixed. It is now possible to call overloaded static methods using a
2938 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2939 and reinterpret_cast<> are now handled by the C++ expression parser.
2943 Xilinx MicroBlaze microblaze-*-*
2948 Xilinx MicroBlaze microblaze
2951 * Multi-program debugging.
2953 GDB now has support for multi-program (a.k.a. multi-executable or
2954 multi-exec) debugging. This allows for debugging multiple inferiors
2955 simultaneously each running a different program under the same GDB
2956 session. See "Debugging Multiple Inferiors and Programs" in the
2957 manual for more information. This implied some user visible changes
2958 in the multi-inferior support. For example, "info inferiors" now
2959 lists inferiors that are not running yet or that have exited
2960 already. See also "New commands" and "New options" below.
2962 * New tracing features
2964 GDB's tracepoint facility now includes several new features:
2966 ** Trace state variables
2968 GDB tracepoints now include support for trace state variables, which
2969 are variables managed by the target agent during a tracing
2970 experiment. They are useful for tracepoints that trigger each
2971 other, so for instance one tracepoint can count hits in a variable,
2972 and then a second tracepoint has a condition that is true when the
2973 count reaches a particular value. Trace state variables share the
2974 $-syntax of GDB convenience variables, and can appear in both
2975 tracepoint actions and condition expressions. Use the "tvariable"
2976 command to create, and "info tvariables" to view; see "Trace State
2977 Variables" in the manual for more detail.
2981 GDB now includes an option for defining fast tracepoints, which
2982 targets may implement more efficiently, such as by installing a jump
2983 into the target agent rather than a trap instruction. The resulting
2984 speedup can be by two orders of magnitude or more, although the
2985 tradeoff is that some program locations on some target architectures
2986 might not allow fast tracepoint installation, for instance if the
2987 instruction to be replaced is shorter than the jump. To request a
2988 fast tracepoint, use the "ftrace" command, with syntax identical to
2989 the regular trace command.
2991 ** Disconnected tracing
2993 It is now possible to detach GDB from the target while it is running
2994 a trace experiment, then reconnect later to see how the experiment
2995 is going. In addition, a new variable disconnected-tracing lets you
2996 tell the target agent whether to continue running a trace if the
2997 connection is lost unexpectedly.
3001 GDB now has the ability to save the trace buffer into a file, and
3002 then use that file as a target, similarly to you can do with
3003 corefiles. You can select trace frames, print data that was
3004 collected in them, and use tstatus to display the state of the
3005 tracing run at the moment that it was saved. To create a trace
3006 file, use "tsave <filename>", and to use it, do "target tfile
3009 ** Circular trace buffer
3011 You can ask the target agent to handle the trace buffer as a
3012 circular buffer, discarding the oldest trace frames to make room for
3013 newer ones, by setting circular-trace-buffer to on. This feature may
3014 not be available for all target agents.
3019 The disassemble command, when invoked with two arguments, now requires
3020 the arguments to be comma-separated.
3023 The info variables command now displays variable definitions. Files
3024 which only declare a variable are not shown.
3027 The source command is now capable of sourcing Python scripts.
3028 This feature is dependent on the debugger being build with Python
3031 Related to this enhancement is also the introduction of a new command
3032 "set script-extension" (see below).
3034 * New commands (for set/show, see "New options" below)
3036 record save [<FILENAME>]
3037 Save a file (in core file format) containing the process record
3038 execution log for replay debugging at a later time.
3040 record restore <FILENAME>
3041 Restore the process record execution log that was saved at an
3042 earlier time, for replay debugging.
3044 add-inferior [-copies <N>] [-exec <FILENAME>]
3047 clone-inferior [-copies <N>] [ID]
3048 Make a new inferior ready to execute the same program another
3049 inferior has loaded.
3054 maint info program-spaces
3055 List the program spaces loaded into GDB.
3057 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3058 show remote interrupt-sequence
3059 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3060 as the sequence to the remote target in order to interrupt the execution.
3061 Ctrl-C is a default. Some system prefers BREAK which is high level of
3062 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3063 Magic SysRq g. It is BREAK signal and character 'g'.
3065 set remote interrupt-on-connect [on | off]
3066 show remote interrupt-on-connect
3067 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3068 remote target when gdb connects to it. This is needed when you debug
3071 set remotebreak [on | off]
3073 Deprecated. Use "set/show remote interrupt-sequence" instead.
3075 tvariable $NAME [ = EXP ]
3076 Create or modify a trace state variable.
3079 List trace state variables and their values.
3081 delete tvariable $NAME ...
3082 Delete one or more trace state variables.
3085 Evaluate the given expressions without collecting anything into the
3086 trace buffer. (Valid in tracepoint actions only.)
3088 ftrace FN / FILE:LINE / *ADDR
3089 Define a fast tracepoint at the given function, line, or address.
3091 * New expression syntax
3093 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3094 GDB now parses 0b101010 identically with 42.
3098 set follow-exec-mode new|same
3099 show follow-exec-mode
3100 Control whether GDB reuses the same inferior across an exec call or
3101 creates a new one. This is useful to be able to restart the old
3102 executable after the inferior having done an exec call.
3104 set default-collect EXPR, ...
3105 show default-collect
3106 Define a list of expressions to be collected at each tracepoint.
3107 This is a useful way to ensure essential items are not overlooked,
3108 such as registers or a critical global variable.
3110 set disconnected-tracing
3111 show disconnected-tracing
3112 If set to 1, the target is instructed to continue tracing if it
3113 loses its connection to GDB. If 0, the target is to stop tracing
3116 set circular-trace-buffer
3117 show circular-trace-buffer
3118 If set to on, the target is instructed to use a circular trace buffer
3119 and discard the oldest trace frames instead of stopping the trace due
3120 to a full trace buffer. If set to off, the trace stops when the buffer
3121 fills up. Some targets may not support this.
3123 set script-extension off|soft|strict
3124 show script-extension
3125 If set to "off", the debugger does not perform any script language
3126 recognition, and all sourced files are assumed to be GDB scripts.
3127 If set to "soft" (the default), files are sourced according to
3128 filename extension, falling back to GDB scripts if the first
3130 If set to "strict", files are sourced according to filename extension.
3132 set ada trust-PAD-over-XVS on|off
3133 show ada trust-PAD-over-XVS
3134 If off, activate a workaround against a bug in the debugging information
3135 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3136 the GCC sources for more information about the GNAT encoding and
3137 PAD types in particular). It is always safe to set this option to
3138 off, but this introduces a slight performance penalty. The default
3141 * Python API Improvements
3143 ** GDB provides the new class gdb.LazyString. This is useful in
3144 some pretty-printing cases. The new method gdb.Value.lazy_string
3145 provides a simple way to create objects of this type.
3147 ** The fields returned by gdb.Type.fields now have an
3148 `is_base_class' attribute.
3150 ** The new method gdb.Type.range returns the range of an array type.
3152 ** The new method gdb.parse_and_eval can be used to parse and
3153 evaluate an expression.
3155 * New remote packets
3158 Define a trace state variable.
3161 Get the current value of a trace state variable.
3164 Set desired tracing behavior upon disconnection.
3167 Set the trace buffer to be linear or circular.
3170 Get data about the tracepoints currently in use.
3174 Process record now works correctly with hardware watchpoints.
3176 Multiple bug fixes have been made to the mips-irix port, making it
3177 much more reliable. In particular:
3178 - Debugging threaded applications is now possible again. Previously,
3179 GDB would hang while starting the program, or while waiting for
3180 the program to stop at a breakpoint.
3181 - Attaching to a running process no longer hangs.
3182 - An error occurring while loading a core file has been fixed.
3183 - Changing the value of the PC register now works again. This fixes
3184 problems observed when using the "jump" command, or when calling
3185 a function from GDB, or even when assigning a new value to $pc.
3186 - With the "finish" and "return" commands, the return value for functions
3187 returning a small array is now correctly printed.
3188 - It is now possible to break on shared library code which gets executed
3189 during a shared library init phase (code executed while executing
3190 their .init section). Previously, the breakpoint would have no effect.
3191 - GDB is now able to backtrace through the signal handler for
3192 non-threaded programs.
3194 PIE (Position Independent Executable) programs debugging is now supported.
3195 This includes debugging execution of PIC (Position Independent Code) shared
3196 libraries although for that, it should be possible to run such libraries as an
3199 *** Changes in GDB 7.0
3201 * GDB now has an interface for JIT compilation. Applications that
3202 dynamically generate code can create symbol files in memory and register
3203 them with GDB. For users, the feature should work transparently, and
3204 for JIT developers, the interface is documented in the GDB manual in the
3205 "JIT Compilation Interface" chapter.
3207 * Tracepoints may now be conditional. The syntax is as for
3208 breakpoints; either an "if" clause appended to the "trace" command,
3209 or the "condition" command is available. GDB sends the condition to
3210 the target for evaluation using the same bytecode format as is used
3211 for tracepoint actions.
3213 * The disassemble command now supports: an optional /r modifier, print the
3214 raw instructions in hex as well as in symbolic form, and an optional /m
3215 modifier to print mixed source+assembly.
3217 * Process record and replay
3219 In a architecture environment that supports ``process record and
3220 replay'', ``process record and replay'' target can record a log of
3221 the process execution, and replay it with both forward and reverse
3224 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3225 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3226 set execution-direction {forward|reverse}, for targets that support
3229 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3230 feature is available with a native GDB running on kernel version
3233 * GDB now has support for multi-byte and wide character sets on the
3234 target. Strings whose character type is wchar_t, char16_t, or
3235 char32_t are now correctly printed. GDB supports wide- and unicode-
3236 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3237 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3238 `printf'. This feature requires iconv to work properly; if your
3239 system does not have a working iconv, GDB can use GNU libiconv. See
3240 the installation instructions for more information.
3242 * GDB now supports automatic retrieval of shared library files from
3243 remote targets. To use this feature, specify a system root that begins
3244 with the `remote:' prefix, either via the `set sysroot' command or via
3245 the `--with-sysroot' configure-time option.
3247 * "info sharedlibrary" now takes an optional regex of libraries to show,
3248 and it now reports if a shared library has no debugging information.
3250 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3251 now complete on file names.
3253 * When completing in expressions, gdb will attempt to limit
3254 completions to allowable structure or union fields, where appropriate.
3255 For instance, consider:
3257 # struct example { int f1; double f2; };
3258 # struct example variable;
3261 If the user types TAB at the end of this command line, the available
3262 completions will be "f1" and "f2".
3264 * Inlined functions are now supported. They show up in backtraces, and
3265 the "step", "next", and "finish" commands handle them automatically.
3267 * GDB now supports the token-splicing (##) and stringification (#)
3268 operators when expanding macros. It also supports variable-arity
3271 * GDB now supports inspecting extra signal information, exported by
3272 the new $_siginfo convenience variable. The feature is currently
3273 implemented on linux ARM, i386 and amd64.
3275 * GDB can now display the VFP floating point registers and NEON vector
3276 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3277 can provide these registers (requires Linux 2.6.30 or later). Remote
3278 and simulator targets may also provide them.
3280 * New remote packets
3283 Search memory for a sequence of bytes.
3286 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3287 operation over reliable transport links. Use of this packet is
3288 controlled by the `set remote noack-packet' command.
3291 Kill the process with the specified process ID. Use this in preference
3292 to `k' when multiprocess protocol extensions are supported.
3295 Obtains additional operating system information
3299 Read or write additional signal information.
3301 * Removed remote protocol undocumented extension
3303 An undocumented extension to the remote protocol's `S' stop reply
3304 packet that permited the stub to pass a process id was removed.
3305 Remote servers should use the `T' stop reply packet instead.
3307 * GDB now supports multiple function calling conventions according to the
3308 DWARF-2 DW_AT_calling_convention function attribute.
3310 * The SH target utilizes the aforementioned change to distinguish between gcc
3311 and Renesas calling convention. It also adds the new CLI commands
3312 `set/show sh calling-convention'.
3314 * GDB can now read compressed debug sections, as produced by GNU gold
3315 with the --compress-debug-sections=zlib flag.
3317 * 64-bit core files are now supported on AIX.
3319 * Thread switching is now supported on Tru64.
3321 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3322 which will be allocated using malloc later in program execution.
3324 * The qXfer:libraries:read remote procotol packet now allows passing a
3325 list of section offsets.
3327 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3328 conditions handling signals delivered during attach or thread creation
3329 have also been fixed.
3331 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3332 From the user's standpoint, all unqualified instances of True and False
3333 are treated as the standard definitions, regardless of context.
3335 * GDB now parses C++ symbol and type names more flexibly. For
3338 template<typename T> class C { };
3341 GDB will now correctly handle all of:
3343 ptype C<char const *>
3344 ptype C<char const*>
3345 ptype C<const char *>
3346 ptype C<const char*>
3348 * New features in the GDB remote stub, gdbserver
3350 - The "--wrapper" command-line argument tells gdbserver to use a
3351 wrapper program to launch programs for debugging.
3353 - On PowerPC and S/390 targets, it is now possible to use a single
3354 gdbserver executable to debug both 32-bit and 64-bit programs.
3355 (This requires gdbserver itself to be built as a 64-bit executable.)
3357 - gdbserver uses the new noack protocol mode for TCP connections to
3358 reduce communications latency, if also supported and enabled in GDB.
3360 - Support for the sparc64-linux-gnu target is now included in
3363 - The amd64-linux build of gdbserver now supports debugging both
3364 32-bit and 64-bit programs.
3366 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3367 now support hardware watchpoints, and will use them automatically
3372 GDB now has support for scripting using Python. Whether this is
3373 available is determined at configure time.
3375 New GDB commands can now be written in Python.
3377 * Ada tasking support
3379 Ada tasks can now be inspected in GDB. The following commands have
3383 Print the list of Ada tasks.
3385 Print detailed information about task number N.
3387 Print the task number of the current task.
3389 Switch the context of debugging to task number N.
3391 * Support for user-defined prefixed commands. The "define" command can
3392 add new commands to existing prefixes, e.g. "target".
3394 * Multi-inferior, multi-process debugging.
3396 GDB now has generalized support for multi-inferior debugging. See
3397 "Debugging Multiple Inferiors" in the manual for more information.
3398 Although availability still depends on target support, the command
3399 set is more uniform now. The GNU/Linux specific multi-forks support
3400 has been migrated to this new framework. This implied some user
3401 visible changes; see "New commands" and also "Removed commands"
3404 * Target descriptions can now describe the target OS ABI. See the
3405 "Target Description Format" section in the user manual for more
3408 * Target descriptions can now describe "compatible" architectures
3409 to indicate that the target can execute applications for a different
3410 architecture in addition to those for the main target architecture.
3411 See the "Target Description Format" section in the user manual for
3414 * Multi-architecture debugging.
3416 GDB now includes general supports for debugging applications on
3417 hybrid systems that use more than one single processor architecture
3418 at the same time. Each such hybrid architecture still requires
3419 specific support to be added. The only hybrid architecture supported
3420 in this version of GDB is the Cell Broadband Engine.
3422 * GDB now supports integrated debugging of Cell/B.E. applications that
3423 use both the PPU and SPU architectures. To enable support for hybrid
3424 Cell/B.E. debugging, you need to configure GDB to support both the
3425 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3426 --enable-targets configure option.
3428 * Non-stop mode debugging.
3430 For some targets, GDB now supports an optional mode of operation in
3431 which you can examine stopped threads while other threads continue
3432 to execute freely. This is referred to as non-stop mode, with the
3433 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3434 section in the user manual for more information.
3436 To be able to support remote non-stop debugging, a remote stub needs
3437 to implement the non-stop mode remote protocol extensions, as
3438 described in the "Remote Non-Stop" section of the user manual. The
3439 GDB remote stub, gdbserver, has been adjusted to support these
3440 extensions on linux targets.
3442 * New commands (for set/show, see "New options" below)
3444 catch syscall [NAME(S) | NUMBER(S)]
3445 Catch system calls. Arguments, which should be names of system
3446 calls or their numbers, mean catch only those syscalls. Without
3447 arguments, every syscall will be caught. When the inferior issues
3448 any of the specified syscalls, GDB will stop and announce the system
3449 call, both when it is called and when its call returns. This
3450 feature is currently available with a native GDB running on the
3451 Linux Kernel, under the following architectures: x86, x86_64,
3452 PowerPC and PowerPC64.
3454 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3456 Search memory for a sequence of bytes.
3458 maint set python print-stack
3459 maint show python print-stack
3460 Show a stack trace when an error is encountered in a Python script.
3463 Invoke CODE by passing it to the Python interpreter.
3468 These allow macros to be defined, undefined, and listed
3472 Show operating system information about processes.
3475 List the inferiors currently under GDB's control.
3478 Switch focus to inferior number NUM.
3481 Detach from inferior number NUM.
3484 Kill inferior number NUM.
3488 set spu stop-on-load
3489 show spu stop-on-load
3490 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3492 set spu auto-flush-cache
3493 show spu auto-flush-cache
3494 Control whether to automatically flush the software-managed cache
3495 during Cell/B.E. debugging.
3497 set sh calling-convention
3498 show sh calling-convention
3499 Control the calling convention used when calling SH target functions.
3502 show debug timestamp
3503 Control display of timestamps with GDB debugging output.
3505 set disassemble-next-line
3506 show disassemble-next-line
3507 Control display of disassembled source lines or instructions when
3510 set remote noack-packet
3511 show remote noack-packet
3512 Set/show the use of remote protocol QStartNoAckMode packet. See above
3513 under "New remote packets."
3515 set remote query-attached-packet
3516 show remote query-attached-packet
3517 Control use of remote protocol `qAttached' (query-attached) packet.
3519 set remote read-siginfo-object
3520 show remote read-siginfo-object
3521 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3524 set remote write-siginfo-object
3525 show remote write-siginfo-object
3526 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3529 set remote reverse-continue
3530 show remote reverse-continue
3531 Control use of remote protocol 'bc' (reverse-continue) packet.
3533 set remote reverse-step
3534 show remote reverse-step
3535 Control use of remote protocol 'bs' (reverse-step) packet.
3537 set displaced-stepping
3538 show displaced-stepping
3539 Control displaced stepping mode. Displaced stepping is a way to
3540 single-step over breakpoints without removing them from the debuggee.
3541 Also known as "out-of-line single-stepping".
3544 show debug displaced
3545 Control display of debugging info for displaced stepping.
3547 maint set internal-error
3548 maint show internal-error
3549 Control what GDB does when an internal error is detected.
3551 maint set internal-warning
3552 maint show internal-warning
3553 Control what GDB does when an internal warning is detected.
3558 Use a wrapper program to launch programs for debugging.
3560 set multiple-symbols (all|ask|cancel)
3561 show multiple-symbols
3562 The value of this variable can be changed to adjust the debugger behavior
3563 when an expression or a breakpoint location contains an ambiguous symbol
3564 name (an overloaded function name, for instance).
3566 set breakpoint always-inserted
3567 show breakpoint always-inserted
3568 Keep breakpoints always inserted in the target, as opposed to inserting
3569 them when resuming the target, and removing them when the target stops.
3570 This option can improve debugger performance on slow remote targets.
3572 set arm fallback-mode (arm|thumb|auto)
3573 show arm fallback-mode
3574 set arm force-mode (arm|thumb|auto)
3576 These commands control how ARM GDB determines whether instructions
3577 are ARM or Thumb. The default for both settings is auto, which uses
3578 the current CPSR value for instructions without symbols; previous
3579 versions of GDB behaved as if "set arm fallback-mode arm".
3581 set disable-randomization
3582 show disable-randomization
3583 Standalone programs run with the virtual address space randomization enabled
3584 by default on some platforms. This option keeps the addresses stable across
3585 multiple debugging sessions.
3589 Control whether other threads are stopped or not when some thread hits
3594 Requests that asynchronous execution is enabled in the target, if available.
3595 In this case, it's possible to resume target in the background, and interact
3596 with GDB while the target is running. "show target-async" displays the
3597 current state of asynchronous execution of the target.
3599 set target-wide-charset
3600 show target-wide-charset
3601 The target-wide-charset is the name of the character set that GDB
3602 uses when printing characters whose type is wchar_t.
3604 set tcp auto-retry (on|off)
3606 set tcp connect-timeout
3607 show tcp connect-timeout
3608 These commands allow GDB to retry failed TCP connections to a remote stub
3609 with a specified timeout period; this is useful if the stub is launched
3610 in parallel with GDB but may not be ready to accept connections immediately.
3612 set libthread-db-search-path
3613 show libthread-db-search-path
3614 Control list of directories which GDB will search for appropriate
3617 set schedule-multiple (on|off)
3618 show schedule-multiple
3619 Allow GDB to resume all threads of all processes or only threads of
3620 the current process.
3624 Use more aggressive caching for accesses to the stack. This improves
3625 performance of remote debugging (particularly backtraces) without
3626 affecting correctness.
3628 set interactive-mode (on|off|auto)
3629 show interactive-mode
3630 Control whether GDB runs in interactive mode (on) or not (off).
3631 When in interactive mode, GDB waits for the user to answer all
3632 queries. Otherwise, GDB does not wait and assumes the default
3633 answer. When set to auto (the default), GDB determines which
3634 mode to use based on the stdin settings.
3639 For program forks, this is replaced by the new more generic `info
3640 inferiors' command. To list checkpoints, you can still use the
3641 `info checkpoints' command, which was an alias for the `info forks'
3645 Replaced by the new `inferior' command. To switch between
3646 checkpoints, you can still use the `restart' command, which was an
3647 alias for the `fork' command.
3650 This is removed, since some targets don't have a notion of
3651 processes. To switch between processes, you can still use the
3652 `inferior' command using GDB's own inferior number.
3655 For program forks, this is replaced by the new more generic `kill
3656 inferior' command. To delete a checkpoint, you can still use the
3657 `delete checkpoint' command, which was an alias for the `delete
3661 For program forks, this is replaced by the new more generic `detach
3662 inferior' command. To detach a checkpoint, you can still use the
3663 `detach checkpoint' command, which was an alias for the `detach
3666 * New native configurations
3668 x86/x86_64 Darwin i[34567]86-*-darwin*
3670 x86_64 MinGW x86_64-*-mingw*
3674 Lattice Mico32 lm32-*
3675 x86 DICOS i[34567]86-*-dicos*
3676 x86_64 DICOS x86_64-*-dicos*
3679 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3680 (mingw32ce) debugging.
3686 These commands were actually not implemented on any target.
3688 *** Changes in GDB 6.8
3690 * New native configurations
3692 NetBSD/hppa hppa*-*netbsd*
3693 Xtensa GNU/Linux xtensa*-*-linux*
3697 NetBSD/hppa hppa*-*-netbsd*
3698 Xtensa GNU/Lunux xtensa*-*-linux*
3700 * Change in command line behavior -- corefiles vs. process ids.
3702 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3703 attaching to process NUMBER fails, GDB no longer attempts to open a
3704 core file named NUMBER. Attaching to a program using the -c option
3705 is no longer supported. Instead, use the '-p' or '--pid' options.
3707 * GDB can now be built as a native debugger for debugging Windows x86
3708 (mingw32) Portable Executable (PE) programs.
3710 * Pending breakpoints no longer change their number when their address
3713 * GDB now supports breakpoints with multiple locations,
3714 including breakpoints on C++ constructors, inside C++ templates,
3715 and in inlined functions.
3717 * GDB's ability to debug optimized code has been improved. GDB more
3718 accurately identifies function bodies and lexical blocks that occupy
3719 more than one contiguous range of addresses.
3721 * Target descriptions can now describe registers for PowerPC.
3723 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3724 registers on PowerPC targets.
3726 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3727 targets even when the libthread_db library is not available.
3729 * The GDB remote stub, gdbserver, now supports the new file transfer
3730 commands (remote put, remote get, and remote delete).
3732 * The GDB remote stub, gdbserver, now supports run and attach in
3733 extended-remote mode.
3735 * hppa*64*-*-hpux11* target broken
3736 The debugger is unable to start a program and fails with the following
3737 error: "Error trying to get information about dynamic linker".
3738 The gdb-6.7 release is also affected.
3740 * GDB now supports the --enable-targets= configure option to allow
3741 building a single GDB executable that supports multiple remote
3742 target architectures.
3744 * GDB now supports debugging C and C++ programs which use the
3745 Decimal Floating Point extension. In addition, the PowerPC target
3746 now has a set of pseudo-registers to inspect decimal float values
3747 stored in two consecutive float registers.
3749 * The -break-insert MI command can optionally create pending
3752 * Improved support for debugging Ada
3753 Many improvements to the Ada language support have been made. These
3755 - Better support for Ada2005 interface types
3756 - Improved handling of arrays and slices in general
3757 - Better support for Taft-amendment types
3758 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3760 - Improved command completion in Ada
3763 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3768 set print frame-arguments (all|scalars|none)
3769 show print frame-arguments
3770 The value of this variable can be changed to control which argument
3771 values should be printed by the debugger when displaying a frame.
3776 Transfer files to and from a remote target, and delete remote files.
3783 Transfer files to and from a remote target, and delete remote files.
3785 * New remote packets
3792 Open, close, read, write, and delete files on the remote system.
3795 Attach to an existing process on the remote system, in extended-remote
3799 Run a new process on the remote system, in extended-remote mode.
3801 *** Changes in GDB 6.7
3803 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3804 bfd, libiberty and opcodes, as revealed by static analysis donated by
3805 Coverity, Inc. (http://scan.coverity.com).
3807 * When looking up multiply-defined global symbols, GDB will now prefer the
3808 symbol definition in the current shared library if it was built using the
3809 -Bsymbolic linker option.
3811 * When the Text User Interface (TUI) is not configured, GDB will now
3812 recognize the -tui command-line option and print a message that the TUI
3815 * The GDB remote stub, gdbserver, now has lower overhead for high
3816 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3818 * GDB for MIPS targets now autodetects whether a remote target provides
3819 32-bit or 64-bit register values.
3821 * Support for C++ member pointers has been improved.
3823 * GDB now understands XML target descriptions, which specify the
3824 target's overall architecture. GDB can read a description from
3825 a local file or over the remote serial protocol.
3827 * Vectors of single-byte data use a new integer type which is not
3828 automatically displayed as character or string data.
3830 * The /s format now works with the print command. It displays
3831 arrays of single-byte integers and pointers to single-byte integers
3834 * Target descriptions can now describe target-specific registers,
3835 for architectures which have implemented the support (currently
3836 only ARM, M68K, and MIPS).
3838 * GDB and the GDB remote stub, gdbserver, now support the XScale
3841 * The GDB remote stub, gdbserver, has been updated to support
3842 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3843 has been rewritten to use the standard GDB remote protocol.
3845 * GDB can now step into C++ functions which are called through thunks.
3847 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3849 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3850 layout. It also supports a TextSeg= and DataSeg= response when only
3851 segment base addresses (rather than offsets) are available.
3853 * The /i format now outputs any trailing branch delay slot instructions
3854 immediately following the last instruction within the count specified.
3856 * The GDB remote protocol "T" stop reply packet now supports a
3857 "library" response. Combined with the new "qXfer:libraries:read"
3858 packet, this response allows GDB to debug shared libraries on targets
3859 where the operating system manages the list of loaded libraries (e.g.
3860 Windows and SymbianOS).
3862 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3863 (DLLs) on Windows and Windows CE targets.
3865 * GDB now supports a faster verification that a .debug file matches its binary
3866 according to its build-id signature, if the signature is present.
3872 Enable or disable hardware flow control (RTS/CTS) on the serial port
3873 when debugging using remote targets.
3875 set mem inaccessible-by-default
3876 show mem inaccessible-by-default
3877 If the target supplies a memory map, for instance via the remote
3878 protocol's "qXfer:memory-map:read" packet, setting this variable
3879 prevents GDB from accessing memory outside the memory map. This
3880 is useful for targets with memory mapped registers or which react
3881 badly to accesses of unmapped address space.
3883 set breakpoint auto-hw
3884 show breakpoint auto-hw
3885 If the target supplies a memory map, for instance via the remote
3886 protocol's "qXfer:memory-map:read" packet, setting this variable
3887 lets GDB use hardware breakpoints automatically for memory regions
3888 where it can not use software breakpoints. This covers both the
3889 "break" command and internal breakpoints used for other commands
3890 including "next" and "finish".
3893 catch exception unhandled
3894 Stop the program execution when Ada exceptions are raised.
3897 Stop the program execution when an Ada assertion failed.
3901 Set an alternate system root for target files. This is a more
3902 general version of "set solib-absolute-prefix", which is now
3903 an alias to "set sysroot".
3906 Provide extended SPU facility status information. This set of
3907 commands is available only when debugging the Cell/B.E. SPU
3910 * New native configurations
3912 OpenBSD/sh sh*-*openbsd*
3915 unset tdesc filename
3917 Use the specified local file as an XML target description, and do
3918 not query the target for its built-in description.
3922 OpenBSD/sh sh*-*-openbsd*
3923 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3924 Toshiba Media Processor mep-elf
3926 * New remote packets
3929 Ignore the specified signals; pass them directly to the debugged program
3930 without stopping other threads or reporting them to GDB.
3932 qXfer:features:read:
3933 Read an XML target description from the target, which describes its
3938 Read or write contents of an spufs file on the target system. These
3939 packets are available only on the Cell/B.E. SPU architecture.
3941 qXfer:libraries:read:
3942 Report the loaded shared libraries. Combined with new "T" packet
3943 response, this packet allows GDB to debug shared libraries on
3944 targets where the operating system manages the list of loaded
3945 libraries (e.g. Windows and SymbianOS).
3949 Support for these obsolete configurations has been removed.
3957 i[34567]86-*-lynxos*
3958 i[34567]86-*-netware*
3959 i[34567]86-*-sco3.2v5*
3960 i[34567]86-*-sco3.2v4*
3962 i[34567]86-*-sysv4.2*
3965 i[34567]86-*-unixware2*
3966 i[34567]86-*-unixware*
3975 * Other removed features
3982 Various m68k-only ROM monitors.
3989 Various Renesas ROM monitors and debugging interfaces for SH and
3994 Support for a Macraigor serial interface to on-chip debugging.
3995 GDB does not directly support the newer parallel or USB
4000 A debug information format. The predecessor to DWARF 2 and
4001 DWARF 3, which are still supported.
4003 Support for the HP aCC compiler on HP-UX/PA-RISC
4005 SOM-encapsulated symbolic debugging information, automatic
4006 invocation of pxdb, and the aCC custom C++ ABI. This does not
4007 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4008 with aCC can still be debugged on an assembly level.
4010 MIPS ".pdr" sections
4012 A MIPS-specific format used to describe stack frame layout
4013 in debugging information.
4017 GDB could work with an older version of Guile to debug
4018 the interpreter and Scheme programs running in it.
4020 set mips stack-arg-size
4021 set mips saved-gpreg-size
4023 Use "set mips abi" to control parameter passing for MIPS.
4025 *** Changes in GDB 6.6
4030 Cell Broadband Engine SPU spu-elf
4032 * GDB can now be configured as a cross-debugger targeting native Windows
4033 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4034 running on a Windows system over TCP/IP to debug Windows programs.
4036 * The GDB remote stub, gdbserver, has been updated to support Windows and
4037 Cygwin debugging. Both single-threaded and multi-threaded programs are
4040 * The "set trust-readonly-sections" command works again. This command was
4041 broken in GDB 6.3, 6.4, and 6.5.
4043 * The "load" command now supports writing to flash memory, if the remote
4044 stub provides the required support.
4046 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4047 longer requires symbolic debug information (e.g. DWARF-2).
4052 unset substitute-path
4053 show substitute-path
4054 Manage a list of substitution rules that GDB uses to rewrite the name
4055 of the directories where the sources are located. This can be useful
4056 for instance when the sources were moved to a different location
4057 between compilation and debugging.
4061 Print each CLI command as it is executed. Each command is prefixed with
4062 a number of `+' symbols representing the nesting depth.
4063 The source command now has a `-v' option to enable the same feature.
4067 The ARM Demon monitor support (RDP protocol, "target rdp").
4069 Kernel Object Display, an embedded debugging feature which only worked with
4070 an obsolete version of Cisco IOS.
4072 The 'set download-write-size' and 'show download-write-size' commands.
4074 * New remote packets
4077 Tell a stub about GDB client features, and request remote target features.
4078 The first feature implemented is PacketSize, which allows the target to
4079 specify the size of packets it can handle - to minimize the number of
4080 packets required and improve performance when connected to a remote
4084 Fetch an OS auxilliary vector from the remote stub. This packet is a
4085 more efficient replacement for qPart:auxv:read.
4087 qXfer:memory-map:read:
4088 Fetch a memory map from the remote stub, including information about
4089 RAM, ROM, and flash memory devices.
4094 Erase and program a flash memory device.
4096 * Removed remote packets
4099 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4100 used it, and only gdbserver implemented it.
4102 *** Changes in GDB 6.5
4106 Renesas M32C/M16C m32c-elf
4108 Morpho Technologies ms1 ms1-elf
4112 init-if-undefined Initialize a convenience variable, but
4113 only if it doesn't already have a value.
4115 The following commands are presently only implemented for native GNU/Linux:
4117 checkpoint Save a snapshot of the program state.
4119 restart <n> Return the program state to a
4120 previously saved state.
4122 info checkpoints List currently saved checkpoints.
4124 delete-checkpoint <n> Delete a previously saved checkpoint.
4126 set|show detach-on-fork Tell gdb whether to detach from a newly
4127 forked process, or to keep debugging it.
4129 info forks List forks of the user program that
4130 are available to be debugged.
4132 fork <n> Switch to debugging one of several
4133 forks of the user program that are
4134 available to be debugged.
4136 delete-fork <n> Delete a fork from the list of forks
4137 that are available to be debugged (and
4138 kill the forked process).
4140 detach-fork <n> Delete a fork from the list of forks
4141 that are available to be debugged (and
4142 allow the process to continue).
4146 Morpho Technologies ms2 ms1-elf
4148 * Improved Windows host support
4150 GDB now builds as a cross debugger hosted on i686-mingw32, including
4151 native console support, and remote communications using either
4152 network sockets or serial ports.
4154 * Improved Modula-2 language support
4156 GDB can now print most types in the Modula-2 syntax. This includes:
4157 basic types, set types, record types, enumerated types, range types,
4158 pointer types and ARRAY types. Procedure var parameters are correctly
4159 printed and hexadecimal addresses and character constants are also
4160 written in the Modula-2 syntax. Best results can be obtained by using
4161 GNU Modula-2 together with the -gdwarf-2 command line option.
4165 The ARM rdi-share module.
4167 The Netware NLM debug server.
4169 *** Changes in GDB 6.4
4171 * New native configurations
4173 OpenBSD/arm arm*-*-openbsd*
4174 OpenBSD/mips64 mips64-*-openbsd*
4178 Morpho Technologies ms1 ms1-elf
4180 * New command line options
4182 --batch-silent As for --batch, but totally silent.
4183 --return-child-result The debugger will exist with the same value
4184 the child (debugged) program exited with.
4185 --eval-command COMMAND, -ex COMMAND
4186 Execute a single GDB CLI command. This may be
4187 specified multiple times and in conjunction
4188 with the --command (-x) option.
4190 * Deprecated commands removed
4192 The following commands, that were deprecated in 2000, have been
4196 set|show arm disassembly-flavor set|show arm disassembler
4197 othernames set arm disassembler
4198 set|show remotedebug set|show debug remote
4199 set|show archdebug set|show debug arch
4200 set|show eventdebug set|show debug event
4203 * New BSD user-level threads support
4205 It is now possible to debug programs using the user-level threads
4206 library on OpenBSD and FreeBSD. Currently supported (target)
4209 FreeBSD/amd64 x86_64-*-freebsd*
4210 FreeBSD/i386 i386-*-freebsd*
4211 OpenBSD/i386 i386-*-openbsd*
4213 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4214 are not yet supported.
4216 * New support for Matsushita MN10300 w/sim added
4217 (Work in progress). mn10300-elf.
4219 * REMOVED configurations and files
4221 VxWorks and the XDR protocol *-*-vxworks
4222 Motorola MCORE mcore-*-*
4223 National Semiconductor NS32000 ns32k-*-*
4225 * New "set print array-indexes" command
4227 After turning this setting "on", GDB prints the index of each element
4228 when displaying arrays. The default is "off" to preserve the previous
4231 * VAX floating point support
4233 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4235 * User-defined command support
4237 In addition to using $arg0..$arg9 for argument passing, it is now possible
4238 to use $argc to determine now many arguments have been passed. See the
4239 section on user-defined commands in the user manual for more information.
4241 *** Changes in GDB 6.3:
4243 * New command line option
4245 GDB now accepts -l followed by a number to set the timeout for remote
4248 * GDB works with GCC -feliminate-dwarf2-dups
4250 GDB now supports a more compact representation of DWARF-2 debug
4251 information using DW_FORM_ref_addr references. These are produced
4252 by GCC with the option -feliminate-dwarf2-dups and also by some
4253 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4254 to use -feliminate-dwarf2-dups.
4256 * Internationalization
4258 When supported by the host system, GDB will be built with
4259 internationalization (libintl). The task of marking up the sources is
4260 continued, we're looking forward to our first translation.
4264 Initial support for debugging programs compiled with the GNAT
4265 implementation of the Ada programming language has been integrated
4266 into GDB. In this release, support is limited to expression evaluation.
4268 * New native configurations
4270 GNU/Linux/m32r m32r-*-linux-gnu
4274 GDB's remote protocol now includes support for the 'p' packet. This
4275 packet is used to fetch individual registers from a remote inferior.
4277 * END-OF-LIFE registers[] compatibility module
4279 GDB's internal register infrastructure has been completely rewritten.
4280 The new infrastructure making possible the implementation of key new
4281 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4284 GDB 6.3 will be the last release to include the the registers[]
4285 compatibility module that allowed out-of-date configurations to
4286 continue to work. This change directly impacts the following
4296 powerpc bdm protocol
4298 Unless there is activity to revive these configurations, they will be
4299 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4301 * OBSOLETE configurations and files
4303 Configurations that have been declared obsolete in this release have
4304 been commented out. Unless there is activity to revive these
4305 configurations, the next release of GDB will have their sources
4306 permanently REMOVED.
4315 *** Changes in GDB 6.2.1:
4317 * MIPS `break main; run' gave an heuristic-fence-post warning
4319 When attempting to run even a simple program, a warning about
4320 heuristic-fence-post being hit would be reported. This problem has
4323 * MIPS IRIX 'long double' crashed GDB
4325 When examining a long double variable, GDB would get a segmentation
4326 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4327 IRIX long double values).
4331 A bug in the VAX stack code was causing problems with the "next"
4332 command. This problem has been fixed.
4334 *** Changes in GDB 6.2:
4336 * Fix for ``many threads''
4338 On GNU/Linux systems that use the NPTL threads library, a program
4339 rapidly creating and deleting threads would confuse GDB leading to the
4342 ptrace: No such process.
4343 thread_db_get_info: cannot get thread info: generic error
4345 This problem has been fixed.
4347 * "-async" and "-noasync" options removed.
4349 Support for the broken "-noasync" option has been removed (it caused
4352 * New ``start'' command.
4354 This command runs the program until the begining of the main procedure.
4356 * New BSD Kernel Data Access Library (libkvm) interface
4358 Using ``target kvm'' it is now possible to debug kernel core dumps and
4359 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4360 platforms. Currently supported (native-only) configurations are:
4362 FreeBSD/amd64 x86_64-*-freebsd*
4363 FreeBSD/i386 i?86-*-freebsd*
4364 NetBSD/i386 i?86-*-netbsd*
4365 NetBSD/m68k m68*-*-netbsd*
4366 NetBSD/sparc sparc-*-netbsd*
4367 OpenBSD/amd64 x86_64-*-openbsd*
4368 OpenBSD/i386 i?86-*-openbsd*
4369 OpenBSD/m68k m68*-openbsd*
4370 OpenBSD/sparc sparc-*-openbsd*
4372 * Signal trampoline code overhauled
4374 Many generic problems with GDB's signal handling code have been fixed.
4375 These include: backtraces through non-contiguous stacks; recognition
4376 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4377 call; backtrace through a signal trampoline; step into and out of
4378 signal handlers; and single-stepping in the signal trampoline.
4380 Please note that kernel bugs are a limiting factor here. These
4381 features have been shown to work on an s390 GNU/Linux system that
4382 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4384 * Cygwin support for DWARF 2 added.
4386 * New native configurations
4388 GNU/Linux/hppa hppa*-*-linux*
4389 OpenBSD/hppa hppa*-*-openbsd*
4390 OpenBSD/m68k m68*-*-openbsd*
4391 OpenBSD/m88k m88*-*-openbsd*
4392 OpenBSD/powerpc powerpc-*-openbsd*
4393 NetBSD/vax vax-*-netbsd*
4394 OpenBSD/vax vax-*-openbsd*
4396 * END-OF-LIFE frame compatibility module
4398 GDB's internal frame infrastructure has been completely rewritten.
4399 The new infrastructure making it possible to support key new features
4400 including DWARF 2 Call Frame Information. To aid in the task of
4401 migrating old configurations to this new infrastructure, a
4402 compatibility module, that allowed old configurations to continue to
4403 work, was also included.
4405 GDB 6.2 will be the last release to include this frame compatibility
4406 module. This change directly impacts the following configurations:
4416 Unless there is activity to revive these configurations, they will be
4417 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4419 * REMOVED configurations and files
4421 Sun 3, running SunOS 3 m68*-*-sunos3*
4422 Sun 3, running SunOS 4 m68*-*-sunos4*
4423 Sun 2, running SunOS 3 m68000-*-sunos3*
4424 Sun 2, running SunOS 4 m68000-*-sunos4*
4425 Motorola 680x0 running LynxOS m68*-*-lynxos*
4426 AT&T 3b1/Unix pc m68*-att-*
4427 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4428 decstation mips-dec-* mips-little-*
4429 riscos mips-*-riscos* mips-*-sysv*
4430 sonymips mips-sony-*
4431 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4433 *** Changes in GDB 6.1.1:
4435 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4437 The TUI (Text-mode User Interface) is now built as part of a default
4438 GDB configuration. It is enabled by either selecting the TUI with the
4439 command line option "-i=tui" or by running the separate "gdbtui"
4440 program. For more information on the TUI, see the manual "Debugging
4443 * Pending breakpoint support (also included in GDB 6.1)
4445 Support has been added to allow you to specify breakpoints in shared
4446 libraries that have not yet been loaded. If a breakpoint location
4447 cannot be found, and the "breakpoint pending" option is set to auto,
4448 GDB queries you if you wish to make the breakpoint pending on a future
4449 shared-library load. If and when GDB resolves the breakpoint symbol,
4450 the pending breakpoint is removed as one or more regular breakpoints
4453 Pending breakpoints are very useful for GCJ Java debugging.
4455 * Fixed ISO-C build problems
4457 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4458 non ISO-C code that stopped them being built using a more strict ISO-C
4459 compiler (e.g., IBM's C compiler).
4461 * Fixed build problem on IRIX 5
4463 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4464 wasn't able to compile compile on an IRIX 5 system.
4466 * Added execute permission to gdb/gdbserver/configure
4468 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4469 permission. This bug would cause configure to fail on a number of
4470 systems (Solaris, IRIX). Ref: server/519.
4472 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4474 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4475 has been updated to use constant array sizes.
4477 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4479 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4480 its generated DWARF Call Frame Info. This encoding was causing GDB to
4481 panic, that panic has been fixed. Ref: gdb/1628.
4483 * Fixed a problem when examining parameters in shared library code.
4485 When examining parameters in optimized shared library code generated
4486 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4487 not available''. GDB now correctly displays the variable's value.
4489 *** Changes in GDB 6.1:
4491 * Removed --with-mmalloc
4493 Support for the mmalloc memory manager has been removed, as it
4494 conflicted with the internal gdb byte cache.
4496 * Changes in AMD64 configurations
4498 The AMD64 target now includes the %cs and %ss registers. As a result
4499 the AMD64 remote protocol has changed; this affects the floating-point
4500 and SSE registers. If you rely on those registers for your debugging,
4501 you should upgrade gdbserver on the remote side.
4503 * Revised SPARC target
4505 The SPARC target has been completely revised, incorporating the
4506 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4507 support for LynxOS and SunOS 4 has been dropped. Calling functions
4508 from within GDB on operating systems with a non-executable stack
4509 (Solaris, OpenBSD) now works.
4513 GDB has a new C++ demangler which does a better job on the mangled
4514 names generated by current versions of g++. It also runs faster, so
4515 with this and other changes gdb should now start faster on large C++
4518 * DWARF 2 Location Expressions
4520 GDB support for location expressions has been extended to support function
4521 arguments and frame bases. Older versions of GDB could crash when they
4524 * C++ nested types and namespaces
4526 GDB's support for nested types and namespaces in C++ has been
4527 improved, especially if you use the DWARF 2 debugging format. (This
4528 is the default for recent versions of GCC on most platforms.)
4529 Specifically, if you have a class "Inner" defined within a class or
4530 namespace "Outer", then GDB realizes that the class's name is
4531 "Outer::Inner", not simply "Inner". This should greatly reduce the
4532 frequency of complaints about not finding RTTI symbols. In addition,
4533 if you are stopped at inside of a function defined within a namespace,
4534 GDB modifies its name lookup accordingly.
4536 * New native configurations
4538 NetBSD/amd64 x86_64-*-netbsd*
4539 OpenBSD/amd64 x86_64-*-openbsd*
4540 OpenBSD/alpha alpha*-*-openbsd*
4541 OpenBSD/sparc sparc-*-openbsd*
4542 OpenBSD/sparc64 sparc64-*-openbsd*
4544 * New debugging protocols
4546 M32R with SDI protocol m32r-*-elf*
4548 * "set prompt-escape-char" command deleted.
4550 The command "set prompt-escape-char" has been deleted. This command,
4551 and its very obscure effet on GDB's prompt, was never documented,
4552 tested, nor mentioned in the NEWS file.
4554 * OBSOLETE configurations and files
4556 Configurations that have been declared obsolete in this release have
4557 been commented out. Unless there is activity to revive these
4558 configurations, the next release of GDB will have their sources
4559 permanently REMOVED.
4561 Sun 3, running SunOS 3 m68*-*-sunos3*
4562 Sun 3, running SunOS 4 m68*-*-sunos4*
4563 Sun 2, running SunOS 3 m68000-*-sunos3*
4564 Sun 2, running SunOS 4 m68000-*-sunos4*
4565 Motorola 680x0 running LynxOS m68*-*-lynxos*
4566 AT&T 3b1/Unix pc m68*-att-*
4567 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4568 decstation mips-dec-* mips-little-*
4569 riscos mips-*-riscos* mips-*-sysv*
4570 sonymips mips-sony-*
4571 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4573 * REMOVED configurations and files
4575 SGI Irix-4.x mips-sgi-irix4 or iris4
4576 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4577 Z8000 simulator z8k-zilog-none or z8ksim
4578 Matsushita MN10200 w/simulator mn10200-*-*
4579 H8/500 simulator h8500-hitachi-hms or h8500hms
4580 HP/PA running BSD hppa*-*-bsd*
4581 HP/PA running OSF/1 hppa*-*-osf*
4582 HP/PA Pro target hppa*-*-pro*
4583 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4584 386BSD i[3456]86-*-bsd*
4585 Sequent family i[3456]86-sequent-sysv4*
4586 i[3456]86-sequent-sysv*
4587 i[3456]86-sequent-bsd*
4588 SPARC running LynxOS sparc-*-lynxos*
4589 SPARC running SunOS 4 sparc-*-sunos4*
4590 Tsqware Sparclet sparclet-*-*
4591 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4593 *** Changes in GDB 6.0:
4597 Support for debugging the Objective-C programming language has been
4598 integrated into GDB.
4600 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4602 DWARF 2's Call Frame Information makes available compiler generated
4603 information that more exactly describes the program's run-time stack.
4604 By using this information, GDB is able to provide more robust stack
4607 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4608 have been updated to use a new backtrace mechanism which includes
4609 DWARF 2 CFI support.
4613 GDB's remote protocol has been extended to include support for hosted
4614 file I/O (where the remote target uses GDB's file system). See GDB's
4615 remote protocol documentation for details.
4617 * All targets using the new architecture framework.
4619 All of GDB's targets have been updated to use the new internal
4620 architecture framework. The way is now open for future GDB releases
4621 to include cross-architecture native debugging support (i386 on amd64,
4624 * GNU/Linux's Thread Local Storage (TLS)
4626 GDB now includes support for for the GNU/Linux implementation of
4627 per-thread variables.
4629 * GNU/Linux's Native POSIX Thread Library (NPTL)
4631 GDB's thread code has been updated to work with either the new
4632 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4634 * Separate debug info.
4636 GDB, in conjunction with BINUTILS, now supports a mechanism for
4637 automatically loading debug information from a separate file. Instead
4638 of shipping full debug and non-debug versions of system libraries,
4639 system integrators can now instead ship just the stripped libraries
4640 and optional debug files.
4642 * DWARF 2 Location Expressions
4644 DWARF 2 Location Expressions allow the compiler to more completely
4645 describe the location of variables (even in optimized code) to the
4648 GDB now includes preliminary support for location expressions (support
4649 for DW_OP_piece is still missing).
4653 A number of long standing bugs that caused GDB to die while starting a
4654 Java application have been fixed. GDB's Java support is now
4655 considered "useable".
4657 * GNU/Linux support for fork, vfork, and exec.
4659 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4660 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4663 * GDB supports logging output to a file
4665 There are two new commands, "set logging" and "show logging", which can be
4666 used to capture GDB's output to a file.
4668 * The meaning of "detach" has changed for gdbserver
4670 The "detach" command will now resume the application, as documented. To
4671 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4674 * d10v, m68hc11 `regs' command deprecated
4676 The `info registers' command has been updated so that it displays the
4677 registers using a format identical to the old `regs' command.
4681 A new command, "maint set profile on/off", has been added. This command can
4682 be used to enable or disable profiling while running GDB, to profile a
4683 session or a set of commands. In addition there is a new configure switch,
4684 "--enable-profiling", which will cause GDB to be compiled with profiling
4685 data, for more informative profiling results.
4687 * Default MI syntax changed to "mi2".
4689 The default MI (machine interface) syntax, enabled by the command line
4690 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4691 "mi1", can be enabled by specifying the option "-i=mi1".
4693 Support for the original "mi0" syntax (included in GDB 5.0) has been
4696 Fix for gdb/192: removed extraneous space when displaying frame level.
4697 Fix for gdb/672: update changelist is now output in mi list format.
4698 Fix for gdb/702: a -var-assign that updates the value now shows up
4699 in a subsequent -var-update.
4701 * New native configurations.
4703 FreeBSD/amd64 x86_64-*-freebsd*
4705 * Multi-arched targets.
4707 HP/PA HPUX11 hppa*-*-hpux*
4708 Renesas M32R/D w/simulator m32r-*-elf*
4710 * OBSOLETE configurations and files
4712 Configurations that have been declared obsolete in this release have
4713 been commented out. Unless there is activity to revive these
4714 configurations, the next release of GDB will have their sources
4715 permanently REMOVED.
4717 Z8000 simulator z8k-zilog-none or z8ksim
4718 Matsushita MN10200 w/simulator mn10200-*-*
4719 H8/500 simulator h8500-hitachi-hms or h8500hms
4720 HP/PA running BSD hppa*-*-bsd*
4721 HP/PA running OSF/1 hppa*-*-osf*
4722 HP/PA Pro target hppa*-*-pro*
4723 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4724 Sequent family i[3456]86-sequent-sysv4*
4725 i[3456]86-sequent-sysv*
4726 i[3456]86-sequent-bsd*
4727 Tsqware Sparclet sparclet-*-*
4728 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4730 * REMOVED configurations and files
4733 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4734 IBM AIX PS/2 i[3456]86-*-aix
4735 i386 running Mach 3.0 i[3456]86-*-mach3*
4736 i386 running Mach i[3456]86-*-mach*
4737 i386 running OSF/1 i[3456]86-*osf1mk*
4738 HP/Apollo 68k Family m68*-apollo*-sysv*,
4740 m68*-hp-bsd*, m68*-hp-hpux*
4741 Argonaut Risc Chip (ARC) arc-*-*
4742 Mitsubishi D30V d30v-*-*
4743 Fujitsu FR30 fr30-*-elf*
4744 OS/9000 i[34]86-*-os9k
4745 I960 with MON960 i960-*-coff
4747 * MIPS $fp behavior changed
4749 The convenience variable $fp, for the MIPS, now consistently returns
4750 the address of the current frame's base. Previously, depending on the
4751 context, $fp could refer to either $sp or the current frame's base
4752 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4753 The GNU Source-Level Debugger''.
4755 *** Changes in GDB 5.3:
4757 * GNU/Linux shared library multi-threaded performance improved.
4759 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4760 `/proc', in preference to `ptrace' for memory reads. This may result
4761 in an improvement in the start-up time of multi-threaded, shared
4762 library applications when run under GDB. One GDB user writes: ``loads
4763 shared libs like mad''.
4765 * ``gdbserver'' now supports multi-threaded applications on some targets
4767 Support for debugging multi-threaded applications which use
4768 the GNU/Linux LinuxThreads package has been added for
4769 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4770 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4772 * GDB now supports C/C++ preprocessor macros.
4774 GDB now expands preprocessor macro invocations in C/C++ expressions,
4775 and provides various commands for showing macro definitions and how
4778 The new command `macro expand EXPRESSION' expands any macro
4779 invocations in expression, and shows the result.
4781 The new command `show macro MACRO-NAME' shows the definition of the
4782 macro named MACRO-NAME, and where it was defined.
4784 Most compilers don't include information about macros in the debugging
4785 information by default. In GCC 3.1, for example, you need to compile
4786 your program with the options `-gdwarf-2 -g3'. If the macro
4787 information is present in the executable, GDB will read it.
4789 * Multi-arched targets.
4791 DEC Alpha (partial) alpha*-*-*
4792 DEC VAX (partial) vax-*-*
4794 National Semiconductor NS32000 (partial) ns32k-*-*
4795 Motorola 68000 (partial) m68k-*-*
4796 Motorola MCORE mcore-*-*
4800 Fujitsu FRV architecture added by Red Hat frv*-*-*
4803 * New native configurations
4805 Alpha NetBSD alpha*-*-netbsd*
4806 SH NetBSD sh*-*-netbsdelf*
4807 MIPS NetBSD mips*-*-netbsd*
4808 UltraSPARC NetBSD sparc64-*-netbsd*
4810 * OBSOLETE configurations and files
4812 Configurations that have been declared obsolete in this release have
4813 been commented out. Unless there is activity to revive these
4814 configurations, the next release of GDB will have their sources
4815 permanently REMOVED.
4817 Mitsubishi D30V d30v-*-*
4818 OS/9000 i[34]86-*-os9k
4819 IBM AIX PS/2 i[3456]86-*-aix
4820 Fujitsu FR30 fr30-*-elf*
4821 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4822 Argonaut Risc Chip (ARC) arc-*-*
4823 i386 running Mach 3.0 i[3456]86-*-mach3*
4824 i386 running Mach i[3456]86-*-mach*
4825 i386 running OSF/1 i[3456]86-*osf1mk*
4826 HP/Apollo 68k Family m68*-apollo*-sysv*,
4828 m68*-hp-bsd*, m68*-hp-hpux*
4829 I960 with MON960 i960-*-coff
4831 * OBSOLETE languages
4833 CHILL, a Pascal like language used by telecommunications companies.
4835 * REMOVED configurations and files
4837 AMD 29k family via UDI a29k-amd-udi, udi29k
4838 A29K VxWorks a29k-*-vxworks
4839 AMD 29000 embedded, using EBMON a29k-none-none
4840 AMD 29000 embedded with COFF a29k-none-coff
4841 AMD 29000 embedded with a.out a29k-none-aout
4843 testsuite/gdb.hp/gdb.threads-hp/ directory
4845 * New command "set max-user-call-depth <nnn>"
4847 This command allows the user to limit the call depth of user-defined
4848 commands. The default is 1024.
4850 * Changes in FreeBSD/i386 native debugging.
4852 Support for the "generate-core-file" has been added.
4854 * New commands "dump", "append", and "restore".
4856 These commands allow data to be copied from target memory
4857 to a bfd-format or binary file (dump and append), and back
4858 from a file into memory (restore).
4860 * Improved "next/step" support on multi-processor Alpha Tru64.
4862 The previous single-step mechanism could cause unpredictable problems,
4863 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4864 of a software single-step mechanism prevents this.
4866 *** Changes in GDB 5.2.1:
4874 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4875 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4876 Fix, by Joel Brobecker imported from mainline.
4878 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4879 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4880 Fix, by Fred Fish, imported from mainline.
4882 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4883 Surprisingly enough, it works now.
4884 By Michal Ludvig, imported from mainline.
4886 i386 hardware watchpoint support:
4887 avoid misses on second run for some targets.
4888 By Pierre Muller, imported from mainline.
4890 *** Changes in GDB 5.2:
4892 * New command "set trust-readonly-sections on[off]".
4894 This command is a hint that tells gdb that read-only sections
4895 really are read-only (ie. that their contents will not change).
4896 In this mode, gdb will go to the object file rather than the
4897 target to read memory from read-only sections (such as ".text").
4898 This can be a significant performance improvement on some
4899 (notably embedded) targets.
4901 * New command "generate-core-file" (or "gcore").
4903 This new gdb command allows the user to drop a core file of the child
4904 process state at any time. So far it's been implemented only for
4905 GNU/Linux and Solaris, but should be relatively easily ported to other
4906 hosts. Argument is core file name (defaults to core.<pid>).
4908 * New command line option
4910 GDB now accepts --pid or -p followed by a process id.
4912 * Change in command line behavior -- corefiles vs. process ids.
4914 There is a subtle behavior in the way in which GDB handles
4915 command line arguments. The first non-flag argument is always
4916 a program to debug, but the second non-flag argument may either
4917 be a corefile or a process id. Previously, GDB would attempt to
4918 open the second argument as a corefile, and if that failed, would
4919 issue a superfluous error message and then attempt to attach it as
4920 a process. Now, if the second argument begins with a non-digit,
4921 it will be treated as a corefile. If it begins with a digit,
4922 GDB will attempt to attach it as a process, and if no such process
4923 is found, will then attempt to open it as a corefile.
4925 * Changes in ARM configurations.
4927 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4928 configuration is fully multi-arch.
4930 * New native configurations
4932 ARM NetBSD arm*-*-netbsd*
4933 x86 OpenBSD i[3456]86-*-openbsd*
4934 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4935 Sparc64 running FreeBSD sparc64-*-freebsd*
4939 Sanyo XStormy16 xstormy16-elf
4941 * OBSOLETE configurations and files
4943 Configurations that have been declared obsolete in this release have
4944 been commented out. Unless there is activity to revive these
4945 configurations, the next release of GDB will have their sources
4946 permanently REMOVED.
4948 AMD 29k family via UDI a29k-amd-udi, udi29k
4949 A29K VxWorks a29k-*-vxworks
4950 AMD 29000 embedded, using EBMON a29k-none-none
4951 AMD 29000 embedded with COFF a29k-none-coff
4952 AMD 29000 embedded with a.out a29k-none-aout
4954 testsuite/gdb.hp/gdb.threads-hp/ directory
4956 * REMOVED configurations and files
4958 TI TMS320C80 tic80-*-*
4960 PowerPC Solaris powerpcle-*-solaris*
4961 PowerPC Windows NT powerpcle-*-cygwin32
4962 PowerPC Netware powerpc-*-netware*
4963 Harris/CXUX m88k m88*-harris-cxux*
4964 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4965 ns32k-utek-sysv* ns32k-utek-*
4966 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4967 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4968 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4969 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4970 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4972 * Changes to command line processing
4974 The new `--args' feature can be used to specify command-line arguments
4975 for the inferior from gdb's command line.
4977 * Changes to key bindings
4979 There is a new `operate-and-get-next' function bound to `C-o'.
4981 *** Changes in GDB 5.1.1
4983 Fix compile problem on DJGPP.
4985 Fix a problem with floating-point registers on the i386 being
4988 Fix to stop GDB crashing on .debug_str debug info.
4990 Numerous documentation fixes.
4992 Numerous testsuite fixes.
4994 *** Changes in GDB 5.1:
4996 * New native configurations
4998 Alpha FreeBSD alpha*-*-freebsd*
4999 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5000 MIPS GNU/Linux mips*-*-linux*
5001 MIPS SGI Irix 6.x mips*-sgi-irix6*
5002 ia64 AIX ia64-*-aix*
5003 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5007 Motorola 68HC11 and 68HC12 m68hc11-elf
5009 UltraSparc running GNU/Linux sparc64-*-linux*
5011 * OBSOLETE configurations and files
5013 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5014 Harris/CXUX m88k m88*-harris-cxux*
5015 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5016 ns32k-utek-sysv* ns32k-utek-*
5017 TI TMS320C80 tic80-*-*
5019 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5020 PowerPC Solaris powerpcle-*-solaris*
5021 PowerPC Windows NT powerpcle-*-cygwin32
5022 PowerPC Netware powerpc-*-netware*
5023 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5024 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5025 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5026 Apple Macintosh (MPW) host N/A
5028 stuff.c (Program to stuff files into a specially prepared space in kdb)
5029 kdb-start.c (Main loop for the standalone kernel debugger)
5031 Configurations that have been declared obsolete in this release have
5032 been commented out. Unless there is activity to revive these
5033 configurations, the next release of GDB will have their sources
5034 permanently REMOVED.
5036 * REMOVED configurations and files
5038 Altos 3068 m68*-altos-*
5039 Convex c1-*-*, c2-*-*
5041 ARM RISCix arm-*-* (as host)
5045 * GDB has been converted to ISO C.
5047 GDB's source code has been converted to ISO C. In particular, the
5048 sources are fully protoized, and rely on standard headers being
5053 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5055 * The MI enabled by default.
5057 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5058 revised and enabled by default. Packages which use GDB as a debugging
5059 engine behind a UI or another front end are encouraged to switch to
5060 using the GDB/MI interface, instead of the old annotations interface
5061 which is now deprecated.
5063 * Support for debugging Pascal programs.
5065 GDB now includes support for debugging Pascal programs. The following
5066 main features are supported:
5068 - Pascal-specific data types such as sets;
5070 - automatic recognition of Pascal sources based on file-name
5073 - Pascal-style display of data types, variables, and functions;
5075 - a Pascal expression parser.
5077 However, some important features are not yet supported.
5079 - Pascal string operations are not supported at all;
5081 - there are some problems with boolean types;
5083 - Pascal type hexadecimal constants are not supported
5084 because they conflict with the internal variables format;
5086 - support for Pascal objects and classes is not full yet;
5088 - unlike Pascal, GDB is case-sensitive for symbol names.
5090 * Changes in completion.
5092 Commands such as `shell', `run' and `set args', which pass arguments
5093 to inferior programs, now complete on file names, similar to what
5094 users expect at the shell prompt.
5096 Commands which accept locations, such as `disassemble', `print',
5097 `breakpoint', `until', etc. now complete on filenames as well as
5098 program symbols. Thus, if you type "break foob TAB", and the source
5099 files linked into the programs include `foobar.c', that file name will
5100 be one of the candidates for completion. However, file names are not
5101 considered for completion after you typed a colon that delimits a file
5102 name from a name of a function in that file, as in "break foo.c:bar".
5104 `set demangle-style' completes on available demangling styles.
5106 * New platform-independent commands:
5108 It is now possible to define a post-hook for a command as well as a
5109 hook that runs before the command. For more details, see the
5110 documentation of `hookpost' in the GDB manual.
5112 * Changes in GNU/Linux native debugging.
5114 Support for debugging multi-threaded programs has been completely
5115 revised for all platforms except m68k and sparc. You can now debug as
5116 many threads as your system allows you to have.
5118 Attach/detach is supported for multi-threaded programs.
5120 Support for SSE registers was added for x86. This doesn't work for
5121 multi-threaded programs though.
5123 * Changes in MIPS configurations.
5125 Multi-arch support is enabled for all MIPS configurations.
5127 GDB can now be built as native debugger on SGI Irix 6.x systems for
5128 debugging n32 executables. (Debugging 64-bit executables is not yet
5131 * Unified support for hardware watchpoints in all x86 configurations.
5133 Most (if not all) native x86 configurations support hardware-assisted
5134 breakpoints and watchpoints in a unified manner. This support
5135 implements debug register sharing between watchpoints, which allows to
5136 put a virtually infinite number of watchpoints on the same address,
5137 and also supports watching regions up to 16 bytes with several debug
5140 The new maintenance command `maintenance show-debug-regs' toggles
5141 debugging print-outs in functions that insert, remove, and test
5142 watchpoints and hardware breakpoints.
5144 * Changes in the DJGPP native configuration.
5146 New command ``info dos sysinfo'' displays assorted information about
5147 the CPU, OS, memory, and DPMI server.
5149 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5150 display information about segment descriptors stored in GDT, LDT, and
5153 New commands ``info dos pde'' and ``info dos pte'' display entries
5154 from Page Directory and Page Tables (for now works with CWSDPMI only).
5155 New command ``info dos address-pte'' displays the Page Table entry for
5156 a given linear address.
5158 GDB can now pass command lines longer than 126 characters to the
5159 program being debugged (requires an update to the libdbg.a library
5160 which is part of the DJGPP development kit).
5162 DWARF2 debug info is now supported.
5164 It is now possible to `step' and `next' through calls to `longjmp'.
5166 * Changes in documentation.
5168 All GDB documentation was converted to GFDL, the GNU Free
5169 Documentation License.
5171 Tracepoints-related commands are now fully documented in the GDB
5174 TUI, the Text-mode User Interface, is now documented in the manual.
5176 Tracepoints-related commands are now fully documented in the GDB
5179 The "GDB Internals" manual now has an index. It also includes
5180 documentation of `ui_out' functions, GDB coding standards, x86
5181 hardware watchpoints, and memory region attributes.
5183 * GDB's version number moved to ``version.in''
5185 The Makefile variable VERSION has been replaced by the file
5186 ``version.in''. People creating GDB distributions should update the
5187 contents of this file.
5191 GUD support is now a standard part of the EMACS distribution.
5193 *** Changes in GDB 5.0:
5195 * Improved support for debugging FP programs on x86 targets
5197 Unified and much-improved support for debugging floating-point
5198 programs on all x86 targets. In particular, ``info float'' now
5199 displays the FP registers in the same format on all x86 targets, with
5200 greater level of detail.
5202 * Improvements and bugfixes in hardware-assisted watchpoints
5204 It is now possible to watch array elements, struct members, and
5205 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5206 on x86 targets no longer erroneously trigger when the address is
5209 * Improvements in the native DJGPP version of GDB
5211 The distribution now includes all the scripts and auxiliary files
5212 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5213 machines ``out of the box''.
5215 The DJGPP version can now debug programs that use signals. It is
5216 possible to catch signals that happened in the debuggee, deliver
5217 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5218 would kill the program being debugged.) Programs that hook hardware
5219 interrupts (keyboard, timer, etc.) can also be debugged.
5221 It is now possible to debug DJGPP programs that redirect their
5222 standard handles or switch them to raw (as opposed to cooked) mode, or
5223 even close them. The command ``run < foo > bar'' works as expected,
5224 and ``info terminal'' reports useful information about the debuggee's
5225 terminal, including raw/cooked mode, redirection, etc.
5227 The DJGPP version now uses termios functions for console I/O, which
5228 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5231 DOS-style file names with drive letters are now fully supported by
5234 It is now possible to debug DJGPP programs that switch their working
5235 directory. It is also possible to rerun the debuggee any number of
5236 times without restarting GDB; thus, you can use the same setup,
5237 breakpoints, etc. for many debugging sessions.
5239 * New native configurations
5241 ARM GNU/Linux arm*-*-linux*
5242 PowerPC GNU/Linux powerpc-*-linux*
5246 Motorola MCore mcore-*-*
5247 x86 VxWorks i[3456]86-*-vxworks*
5248 PowerPC VxWorks powerpc-*-vxworks*
5249 TI TMS320C80 tic80-*-*
5251 * OBSOLETE configurations
5253 Altos 3068 m68*-altos-*
5254 Convex c1-*-*, c2-*-*
5256 ARM RISCix arm-*-* (as host)
5259 Configurations that have been declared obsolete will be commented out,
5260 but the code will be left in place. If there is no activity to revive
5261 these configurations before the next release of GDB, the sources will
5262 be permanently REMOVED.
5264 * Gould support removed
5266 Support for the Gould PowerNode and NP1 has been removed.
5268 * New features for SVR4
5270 On SVR4 native platforms (such as Solaris), if you attach to a process
5271 without first loading a symbol file, GDB will now attempt to locate and
5272 load symbols from the running process's executable file.
5274 * Many C++ enhancements
5276 C++ support has been greatly improved. Overload resolution now works properly
5277 in almost all cases. RTTI support is on the way.
5279 * Remote targets can connect to a sub-program
5281 A popen(3) style serial-device has been added. This device starts a
5282 sub-process (such as a stand-alone simulator) and then communicates
5283 with that. The sub-program to run is specified using the syntax
5284 ``|<program> <args>'' vis:
5286 (gdb) set remotedebug 1
5287 (gdb) target extended-remote |mn10300-elf-sim program-args
5289 * MIPS 64 remote protocol
5291 A long standing bug in the mips64 remote protocol where by GDB
5292 expected certain 32 bit registers (ex SR) to be transfered as 32
5293 instead of 64 bits has been fixed.
5295 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5296 added to provide backward compatibility with older versions of GDB.
5298 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5300 The command ``set remotebinarydownload'' command has been replaced by
5301 ``set remote X-packet''. Other commands in ``set remote'' family
5302 include ``set remote P-packet''.
5304 * Breakpoint commands accept ranges.
5306 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5307 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5308 ``tracepoint passcount'' also accepts a range of tracepoints.
5310 * ``apropos'' command added.
5312 The ``apropos'' command searches through command names and
5313 documentation strings, printing out matches, making it much easier to
5314 try to find a command that does what you are looking for.
5318 A new machine oriented interface (MI) has been added to GDB. This
5319 interface is designed for debug environments running GDB as a separate
5320 process. This is part of the long term libGDB project. See the
5321 "GDB/MI" chapter of the GDB manual for further information. It can be
5322 enabled by configuring with:
5324 .../configure --enable-gdbmi
5326 *** Changes in GDB-4.18:
5328 * New native configurations
5330 HP-UX 10.20 hppa*-*-hpux10.20
5331 HP-UX 11.x hppa*-*-hpux11.0*
5332 M68K GNU/Linux m68*-*-linux*
5336 Fujitsu FR30 fr30-*-elf*
5337 Intel StrongARM strongarm-*-*
5338 Mitsubishi D30V d30v-*-*
5340 * OBSOLETE configurations
5342 Gould PowerNode, NP1 np1-*-*, pn-*-*
5344 Configurations that have been declared obsolete will be commented out,
5345 but the code will be left in place. If there is no activity to revive
5346 these configurations before the next release of GDB, the sources will
5347 be permanently REMOVED.
5351 As a compatibility experiment, GDB's source files buildsym.h and
5352 buildsym.c have been converted to pure standard C, no longer
5353 containing any K&R compatibility code. We believe that all systems in
5354 use today either come with a standard C compiler, or have a GCC port
5355 available. If this is not true, please report the affected
5356 configuration to bug-gdb@gnu.org immediately. See the README file for
5357 information about getting a standard C compiler if you don't have one
5362 GDB now uses readline 2.2.
5364 * set extension-language
5366 You can now control the mapping between filename extensions and source
5367 languages by using the `set extension-language' command. For instance,
5368 you can ask GDB to treat .c files as C++ by saying
5369 set extension-language .c c++
5370 The command `info extensions' lists all of the recognized extensions
5371 and their associated languages.
5373 * Setting processor type for PowerPC and RS/6000
5375 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5376 you can use the `set processor' command to specify what variant of the
5377 PowerPC family you are debugging. The command
5381 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5382 following PowerPC and RS6000 variants:
5384 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5385 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5387 403GC IBM PowerPC 403GC
5388 505 Motorola PowerPC 505
5389 860 Motorola PowerPC 860 or 850
5390 601 Motorola PowerPC 601
5391 602 Motorola PowerPC 602
5392 603 Motorola/IBM PowerPC 603 or 603e
5393 604 Motorola PowerPC 604 or 604e
5394 750 Motorola/IBM PowerPC 750 or 750
5396 At the moment, this command just tells GDB what to name the
5397 special-purpose processor registers. Since almost all the affected
5398 registers are inaccessible to user-level programs, this command is
5399 only useful for remote debugging in its present form.
5403 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5404 more extensive support for HP-UX. Added features include shared
5405 library support, kernel threads and hardware watchpoints for 11.00,
5406 support for HP's ANSI C and C++ compilers, and a compatibility mode
5407 for xdb and dbx commands.
5411 HP's donation includes the new concept of catchpoints, which is a
5412 generalization of the old catch command. On HP-UX, it is now possible
5413 to catch exec, fork, and vfork, as well as library loading.
5415 This means that the existing catch command has changed; its first
5416 argument now specifies the type of catch to be set up. See the
5417 output of "help catch" for a list of catchpoint types.
5419 * Debugging across forks
5421 On HP-UX, you can choose which process to debug when a fork() happens
5426 HP has donated a curses-based terminal user interface (TUI). To get
5427 it, build with --enable-tui. Although this can be enabled for any
5428 configuration, at present it only works for native HP debugging.
5430 * GDB remote protocol additions
5432 A new protocol packet 'X' that writes binary data is now available.
5433 Default behavior is to try 'X', then drop back to 'M' if the stub
5434 fails to respond. The settable variable `remotebinarydownload'
5435 allows explicit control over the use of 'X'.
5437 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5438 full 64-bit address. The command
5440 set remoteaddresssize 32
5442 can be used to revert to the old behaviour. For existing remote stubs
5443 the change should not be noticed, as the additional address information
5446 In order to assist in debugging stubs, you may use the maintenance
5447 command `packet' to send any text string to the stub. For instance,
5449 maint packet heythere
5451 sends the packet "$heythere#<checksum>". Note that it is very easy to
5452 disrupt a debugging session by sending the wrong packet at the wrong
5455 The compare-sections command allows you to compare section data on the
5456 target to what is in the executable file without uploading or
5457 downloading, by comparing CRC checksums.
5459 * Tracing can collect general expressions
5461 You may now collect general expressions at tracepoints. This requires
5462 further additions to the target-side stub; see tracepoint.c and
5463 doc/agentexpr.texi for further details.
5465 * mask-address variable for Mips
5467 For Mips targets, you may control the zeroing of the upper 32 bits of
5468 a 64-bit address by entering `set mask-address on'. This is mainly
5469 of interest to users of embedded R4xxx and R5xxx processors.
5471 * Higher serial baud rates
5473 GDB's serial code now allows you to specify baud rates 57600, 115200,
5474 230400, and 460800 baud. (Note that your host system may not be able
5475 to achieve all of these rates.)
5479 The i960 configuration now includes an initial implementation of a
5480 builtin simulator, contributed by Jim Wilson.
5483 *** Changes in GDB-4.17:
5485 * New native configurations
5487 Alpha GNU/Linux alpha*-*-linux*
5488 Unixware 2.x i[3456]86-unixware2*
5489 Irix 6.x mips*-sgi-irix6*
5490 PowerPC GNU/Linux powerpc-*-linux*
5491 PowerPC Solaris powerpcle-*-solaris*
5492 Sparc GNU/Linux sparc-*-linux*
5493 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5497 Argonaut Risc Chip (ARC) arc-*-*
5498 Hitachi H8/300S h8300*-*-*
5499 Matsushita MN10200 w/simulator mn10200-*-*
5500 Matsushita MN10300 w/simulator mn10300-*-*
5501 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5502 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5503 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5504 Mitsubishi D10V w/simulator d10v-*-*
5505 Mitsubishi M32R/D w/simulator m32r-*-elf*
5506 Tsqware Sparclet sparclet-*-*
5507 NEC V850 w/simulator v850-*-*
5509 * New debugging protocols
5511 ARM with RDI protocol arm*-*-*
5512 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5513 DDB and LSI variants of PMON protocol mips*-*-*
5514 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5515 PowerPC with SDS protocol powerpc{,le}-*-eabi
5516 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5520 All configurations can now understand and use the DWARF 2 debugging
5521 format. The choice is automatic, if the symbol file contains DWARF 2
5526 GDB now includes basic Java language support. This support is
5527 only useful with Java compilers that produce native machine code.
5529 * solib-absolute-prefix and solib-search-path
5531 For SunOS and SVR4 shared libraries, you may now set the prefix for
5532 loading absolute shared library symbol files, and the search path for
5533 locating non-absolute shared library symbol files.
5535 * Live range splitting
5537 GDB can now effectively debug code for which GCC has performed live
5538 range splitting as part of its optimization. See gdb/doc/LRS for
5539 more details on the expected format of the stabs information.
5543 GDB's support for the GNU Hurd, including thread debugging, has been
5544 updated to work with current versions of the Hurd.
5548 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5549 instruction set. ARM GDB automatically detects when Thumb
5550 instructions are in use, and adjusts disassembly and backtracing
5555 GDB's MIPS target configurations now handle the MIP16 16-bit
5560 GDB now includes support for overlays; if an executable has been
5561 linked such that multiple sections are based at the same address, GDB
5562 will decide which section to use for symbolic info. You can choose to
5563 control the decision manually, using overlay commands, or implement
5564 additional target-side support and use "overlay load-target" to bring
5565 in the overlay mapping. Do "help overlay" for more detail.
5569 The command "info symbol <address>" displays information about
5570 the symbol at the specified address.
5574 The standard remote protocol now includes an extension that allows
5575 asynchronous collection and display of trace data. This requires
5576 extensive support in the target-side debugging stub. Tracing mode
5577 includes a new interaction mode in GDB and new commands: see the
5578 file tracepoint.c for more details.
5582 Configurations for embedded MIPS now include a simulator contributed
5583 by Cygnus Solutions. The simulator supports the instruction sets
5584 of most MIPS variants.
5588 Sparc configurations may now include the ERC32 simulator contributed
5589 by the European Space Agency. The simulator is not built into
5590 Sparc targets by default; configure with --enable-sim to include it.
5594 For target configurations that may include multiple variants of a
5595 basic architecture (such as MIPS and SH), you may now set the
5596 architecture explicitly. "set arch" sets, "info arch" lists
5597 the possible architectures.
5599 *** Changes in GDB-4.16:
5601 * New native configurations
5603 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5604 M68K NetBSD m68k-*-netbsd*
5605 PowerPC AIX 4.x powerpc-*-aix*
5606 PowerPC MacOS powerpc-*-macos*
5607 PowerPC Windows NT powerpcle-*-cygwin32
5608 RS/6000 AIX 4.x rs6000-*-aix4*
5612 ARM with RDP protocol arm-*-*
5613 I960 with MON960 i960-*-coff
5614 MIPS VxWorks mips*-*-vxworks*
5615 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5616 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5618 Matra Sparclet sparclet-*-*
5622 The powerpc-eabi configuration now includes the PSIM simulator,
5623 contributed by Andrew Cagney, with assistance from Mike Meissner.
5624 PSIM is a very elaborate model of the PowerPC, including not only
5625 basic instruction set execution, but also details of execution unit
5626 performance and I/O hardware. See sim/ppc/README for more details.
5630 GDB now works with Solaris 2.5.
5632 * Windows 95/NT native
5634 GDB will now work as a native debugger on Windows 95 and Windows NT.
5635 To build it from source, you must use the "gnu-win32" environment,
5636 which uses a DLL to emulate enough of Unix to run the GNU tools.
5637 Further information, binaries, and sources are available at
5638 ftp.cygnus.com, under pub/gnu-win32.
5640 * dont-repeat command
5642 If a user-defined command includes the command `dont-repeat', then the
5643 command will not be repeated if the user just types return. This is
5644 useful if the command is time-consuming to run, so that accidental
5645 extra keystrokes don't run the same command many times.
5647 * Send break instead of ^C
5649 The standard remote protocol now includes an option to send a break
5650 rather than a ^C to the target in order to interrupt it. By default,
5651 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5653 * Remote protocol timeout
5655 The standard remote protocol includes a new variable `remotetimeout'
5656 that allows you to set the number of seconds before GDB gives up trying
5657 to read from the target. The default value is 2.
5659 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5661 By default GDB will automatically keep track of objects as they are
5662 loaded and unloaded by the dynamic linker. By using the command `set
5663 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5664 when shared library events occur, thus allowing you to set breakpoints
5665 in shared libraries which are explicitly loaded by the inferior.
5667 Note this feature does not work on hpux8. On hpux9 you must link
5668 /usr/lib/end.o into your program. This feature should work
5669 automatically on hpux10.
5671 * Irix 5.x hardware watchpoint support
5673 Irix 5 configurations now support the use of hardware watchpoints.
5675 * Mips protocol "SYN garbage limit"
5677 When debugging a Mips target using the `target mips' protocol, you
5678 may set the number of characters that GDB will ignore by setting
5679 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5680 every character. The default value is 1050.
5682 * Recording and replaying remote debug sessions
5684 If you set `remotelogfile' to the name of a file, gdb will write to it
5685 a recording of a remote debug session. This recording may then be
5686 replayed back to gdb using "gdbreplay". See gdbserver/README for
5687 details. This is useful when you have a problem with GDB while doing
5688 remote debugging; you can make a recording of the session and send it
5689 to someone else, who can then recreate the problem.
5691 * Speedups for remote debugging
5693 GDB includes speedups for downloading and stepping MIPS systems using
5694 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5695 and more efficient S-record downloading.
5697 * Memory use reductions and statistics collection
5699 GDB now uses less memory and reports statistics about memory usage.
5700 Try the `maint print statistics' command, for example.
5702 *** Changes in GDB-4.15:
5704 * Psymtabs for XCOFF
5706 The symbol reader for AIX GDB now uses partial symbol tables. This
5707 can greatly improve startup time, especially for large executables.
5709 * Remote targets use caching
5711 Remote targets now use a data cache to speed up communication with the
5712 remote side. The data cache could lead to incorrect results because
5713 it doesn't know about volatile variables, thus making it impossible to
5714 debug targets which use memory mapped I/O devices. `set remotecache
5715 off' turns the the data cache off.
5717 * Remote targets may have threads
5719 The standard remote protocol now includes support for multiple threads
5720 in the target system, using new protocol commands 'H' and 'T'. See
5721 gdb/remote.c for details.
5725 If GDB is configured with `--enable-netrom', then it will include
5726 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5727 acts as though it is a bank of ROM on the target board, but you can
5728 write into it over the network. GDB's support consists only of
5729 support for fast loading into the emulated ROM; to debug, you must use
5730 another protocol, such as standard remote protocol. The usual
5731 sequence is something like
5733 target nrom <netrom-hostname>
5735 target remote <netrom-hostname>:1235
5739 GDB now includes support for the Apple Macintosh, as a host only. It
5740 may be run as either an MPW tool or as a standalone application, and
5741 it can debug through the serial port. All the usual GDB commands are
5742 available, but to the target command, you must supply "serial" as the
5743 device type instead of "/dev/ttyXX". See mpw-README in the main
5744 directory for more information on how to build. The MPW configuration
5745 scripts */mpw-config.in support only a few targets, and only the
5746 mips-idt-ecoff target has been tested.
5750 GDB configuration now uses autoconf. This is not user-visible,
5751 but does simplify configuration and building.
5755 GDB now supports hpux10.
5757 *** Changes in GDB-4.14:
5759 * New native configurations
5761 x86 FreeBSD i[345]86-*-freebsd
5762 x86 NetBSD i[345]86-*-netbsd
5763 NS32k NetBSD ns32k-*-netbsd
5764 Sparc NetBSD sparc-*-netbsd
5768 A29K VxWorks a29k-*-vxworks
5769 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5770 CPU32 EST-300 emulator m68*-*-est*
5771 PowerPC ELF powerpc-*-elf
5774 * Alpha OSF/1 support for procfs
5776 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5777 possible to attach to running processes. As the mounting of the /proc
5778 filesystem is optional on the Alpha, GDB automatically determines
5779 the availability of /proc during startup. This can lead to problems
5780 if /proc is unmounted after GDB has been started.
5782 * Arguments to user-defined commands
5784 User commands may accept up to 10 arguments separated by whitespace.
5785 Arguments are accessed within the user command via $arg0..$arg9. A
5788 print $arg0 + $arg1 + $arg2
5790 To execute the command use:
5793 Defines the command "adder" which prints the sum of its three arguments.
5794 Note the arguments are text substitutions, so they may reference variables,
5795 use complex expressions, or even perform inferior function calls.
5797 * New `if' and `while' commands
5799 This makes it possible to write more sophisticated user-defined
5800 commands. Both commands take a single argument, which is the
5801 expression to evaluate, and must be followed by the commands to
5802 execute, one per line, if the expression is nonzero, the list being
5803 terminated by the word `end'. The `if' command list may include an
5804 `else' word, which causes the following commands to be executed only
5805 if the expression is zero.
5807 * Fortran source language mode
5809 GDB now includes partial support for Fortran 77. It will recognize
5810 Fortran programs and can evaluate a subset of Fortran expressions, but
5811 variables and functions may not be handled correctly. GDB will work
5812 with G77, but does not yet know much about symbols emitted by other
5815 * Better HPUX support
5817 Most debugging facilities now work on dynamic executables for HPPAs
5818 running hpux9 or later. You can attach to running dynamically linked
5819 processes, but by default the dynamic libraries will be read-only, so
5820 for instance you won't be able to put breakpoints in them. To change
5821 that behavior do the following before running the program:
5827 This will cause the libraries to be mapped private and read-write.
5828 To revert to the normal behavior, do this:
5834 You cannot set breakpoints or examine data in the library until after
5835 the library is loaded if the function/data symbols do not have
5838 GDB can now also read debug symbols produced by the HP C compiler on
5839 HPPAs (sorry, no C++, Fortran or 68k support).
5841 * Target byte order now dynamically selectable
5843 You can choose which byte order to use with a target system, via the
5844 commands "set endian big" and "set endian little", and you can see the
5845 current setting by using "show endian". You can also give the command
5846 "set endian auto", in which case GDB will use the byte order
5847 associated with the executable. Currently, only embedded MIPS
5848 configurations support dynamic selection of target byte order.
5850 * New DOS host serial code
5852 This version uses DPMI interrupts to handle buffered I/O, so you
5853 no longer need to run asynctsr when debugging boards connected to
5856 *** Changes in GDB-4.13:
5858 * New "complete" command
5860 This lists all the possible completions for the rest of the line, if it
5861 were to be given as a command itself. This is intended for use by emacs.
5863 * Trailing space optional in prompt
5865 "set prompt" no longer adds a space for you after the prompt you set. This
5866 allows you to set a prompt which ends in a space or one that does not.
5868 * Breakpoint hit counts
5870 "info break" now displays a count of the number of times the breakpoint
5871 has been hit. This is especially useful in conjunction with "ignore"; you
5872 can ignore a large number of breakpoint hits, look at the breakpoint info
5873 to see how many times the breakpoint was hit, then run again, ignoring one
5874 less than that number, and this will get you quickly to the last hit of
5877 * Ability to stop printing at NULL character
5879 "set print null-stop" will cause GDB to stop printing the characters of
5880 an array when the first NULL is encountered. This is useful when large
5881 arrays actually contain only short strings.
5883 * Shared library breakpoints
5885 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5886 breakpoints in shared libraries before the executable is run.
5888 * Hardware watchpoints
5890 There is a new hardware breakpoint for the watch command for sparclite
5891 targets. See gdb/sparclite/hw_breakpoint.note.
5893 Hardware watchpoints are also now supported under GNU/Linux.
5897 Annotations have been added. These are for use with graphical interfaces,
5898 and are still experimental. Currently only gdba.el uses these.
5900 * Improved Irix 5 support
5902 GDB now works properly with Irix 5.2.
5904 * Improved HPPA support
5906 GDB now works properly with the latest GCC and GAS.
5908 * New native configurations
5910 Sequent PTX4 i[34]86-sequent-ptx4
5911 HPPA running OSF/1 hppa*-*-osf*
5912 Atari TT running SVR4 m68*-*-sysv4*
5913 RS/6000 LynxOS rs6000-*-lynxos*
5917 OS/9000 i[34]86-*-os9k
5918 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5921 * Hitachi SH7000 and E7000-PC ICE support
5923 There is now support for communicating with the Hitachi E7000-PC ICE.
5924 This is available automatically when GDB is configured for the SH.
5928 As usual, a variety of small fixes and improvements, both generic
5929 and configuration-specific. See the ChangeLog for more detail.
5931 *** Changes in GDB-4.12:
5933 * Irix 5 is now supported
5937 GDB-4.12 on the HPPA has a number of changes which make it unable
5938 to debug the output from the currently released versions of GCC and
5939 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5940 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5941 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5944 *** Changes in GDB-4.11:
5946 * User visible changes:
5950 The "set remotedebug" option is now consistent between the mips remote
5951 target, remote targets using the gdb-specific protocol, UDI (AMD's
5952 debug protocol for the 29k) and the 88k bug monitor. It is now an
5953 integer specifying a debug level (normally 0 or 1, but 2 means more
5954 debugging info for the mips target).
5956 * DEC Alpha native support
5958 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5959 debug info, but GDB works fairly well with the DEC compiler and should
5960 work with a future GCC release. See the README file for a few
5961 Alpha-specific notes.
5963 * Preliminary thread implementation
5965 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5967 * LynxOS native and target support for 386
5969 This release has been hosted on LynxOS 2.2, and also can be configured
5970 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5973 * Improvements in C++ mangling/demangling.
5975 This release has much better g++ debugging, specifically in name
5976 mangling/demangling, virtual function calls, print virtual table,
5977 call methods, ...etc.
5979 *** Changes in GDB-4.10:
5981 * User visible changes:
5983 Remote debugging using the GDB-specific (`target remote') protocol now
5984 supports the `load' command. This is only useful if you have some
5985 other way of getting the stub to the target system, and you can put it
5986 somewhere in memory where it won't get clobbered by the download.
5988 Filename completion now works.
5990 When run under emacs mode, the "info line" command now causes the
5991 arrow to point to the line specified. Also, "info line" prints
5992 addresses in symbolic form (as well as hex).
5994 All vxworks based targets now support a user settable option, called
5995 vxworks-timeout. This option represents the number of seconds gdb
5996 should wait for responses to rpc's. You might want to use this if
5997 your vxworks target is, perhaps, a slow software simulator or happens
5998 to be on the far side of a thin network line.
6002 This release contains support for using a DEC alpha as a GDB host for
6003 cross debugging. Native alpha debugging is not supported yet.
6006 *** Changes in GDB-4.9:
6010 This is the first GDB release which is accompanied by a matching testsuite.
6011 The testsuite requires installation of dejagnu, which should be available
6012 via ftp from most sites that carry GNU software.
6016 'Cfront' style demangling has had its name changed to 'ARM' style, to
6017 emphasize that it was written from the specifications in the C++ Annotated
6018 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6019 disclaimers, it still generated too much confusion with users attempting to
6020 use gdb with AT&T cfront.
6024 GDB now uses a standard remote interface to a simulator library.
6025 So far, the library contains simulators for the Zilog Z8001/2, the
6026 Hitachi H8/300, H8/500 and Super-H.
6028 * New targets supported
6030 H8/300 simulator h8300-hitachi-hms or h8300hms
6031 H8/500 simulator h8500-hitachi-hms or h8500hms
6032 SH simulator sh-hitachi-hms or sh
6033 Z8000 simulator z8k-zilog-none or z8ksim
6034 IDT MIPS board over serial line mips-idt-ecoff
6036 Cross-debugging to GO32 targets is supported. It requires a custom
6037 version of the i386-stub.c module which is integrated with the
6038 GO32 memory extender.
6040 * New remote protocols
6042 MIPS remote debugging protocol.
6044 * New source languages supported
6046 This version includes preliminary support for Chill, a Pascal like language
6047 used by telecommunications companies. Chill support is also being integrated
6048 into the GNU compiler, but we don't know when it will be publically available.
6051 *** Changes in GDB-4.8:
6053 * HP Precision Architecture supported
6055 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6056 version of this support was available as a set of patches from the
6057 University of Utah. GDB does not support debugging of programs
6058 compiled with the HP compiler, because HP will not document their file
6059 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6060 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6062 Many problems in the preliminary version have been fixed.
6064 * Faster and better demangling
6066 We have improved template demangling and fixed numerous bugs in the GNU style
6067 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6068 character types (wchar_t) are now supported. Demangling of each symbol is now
6069 only done once, and is cached when the symbol table for a file is read in.
6070 This results in a small increase in memory usage for C programs, a moderate
6071 increase in memory usage for C++ programs, and a fantastic speedup in
6074 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6075 from the specifications in the Annotated Reference Manual, which AT&T's
6076 compiler does not actually implement.
6078 * G++ multiple inheritance compiler problem
6080 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6081 inheritance lattices was reworked to properly discover ambiguities. We
6082 recently found an example which causes this new algorithm to fail in a
6083 very subtle way, producing bad debug information for those classes.
6084 The file 'gcc.patch' (in this directory) can be applied to gcc to
6085 circumvent the problem. A future GCC release will contain a complete
6088 The previous G++ debug info problem (mentioned below for the gdb-4.7
6089 release) is fixed in gcc version 2.3.2.
6091 * Improved configure script
6093 The `configure' script will now attempt to guess your system type if
6094 you don't supply a host system type. The old scheme of supplying a
6095 host system triplet is preferable over using this. All the magic is
6096 done in the new `config.guess' script. Examine it for details.
6098 We have also brought our configure script much more in line with the FSF's
6099 version. It now supports the --with-xxx options. In particular,
6100 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6101 The resulting GDB will not be able to read arbitrary object file formats --
6102 only the format ``expected'' to be used on the configured target system.
6103 We hope to make this the default in a future release.
6105 * Documentation improvements
6107 There's new internal documentation on how to modify GDB, and how to
6108 produce clean changes to the code. We implore people to read it
6109 before submitting changes.
6111 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6112 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6113 `info' files are also provided. To build `info' files from scratch,
6114 you will need the latest `makeinfo' release, which will be available in
6115 a future texinfo-X.Y release.
6117 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6118 We're not sure exactly which versions have this problem, but it has
6119 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6120 or better. If that isn't possible, there is a patch in
6121 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6122 around this problem.
6126 GDB now supports array constants that can be used in expressions typed in by
6127 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6128 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6131 The new directory `gdb/sparclite' contains a program that demonstrates
6132 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6134 * New native hosts supported
6136 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6137 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6139 * New targets supported
6141 AMD 29k family via UDI a29k-amd-udi or udi29k
6143 * New file formats supported
6145 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6146 HPUX core files, and SCO 3.2v2 core files.
6150 Attaching to processes now works again; thanks for the many bug reports.
6152 We have also stomped on a bunch of core dumps caused by
6153 printf_filtered("%s") problems.
6155 We eliminated a copyright problem on the rpc and ptrace header files
6156 for VxWorks, which was discovered at the last minute during the 4.7
6157 release. You should now be able to build a VxWorks GDB.
6159 You can now interrupt gdb while an attached process is running. This
6160 will cause the attached process to stop, and give control back to GDB.
6162 We fixed problems caused by using too many file descriptors
6163 for reading symbols from object files and libraries. This was
6164 especially a problem for programs that used many (~100) shared
6167 The `step' command now only enters a subroutine if there is line number
6168 information for the subroutine. Otherwise it acts like the `next'
6169 command. Previously, `step' would enter subroutines if there was
6170 any debugging information about the routine. This avoids problems
6171 when using `cc -g1' on MIPS machines.
6173 * Internal improvements
6175 GDB's internal interfaces have been improved to make it easier to support
6176 debugging of multiple languages in the future.
6178 GDB now uses a common structure for symbol information internally.
6179 Minimal symbols (derived from linkage symbols in object files), partial
6180 symbols (from a quick scan of debug information), and full symbols
6181 contain a common subset of information, making it easier to write
6182 shared code that handles any of them.
6184 * New command line options
6186 We now accept --silent as an alias for --quiet.
6190 The memory-mapped-malloc library is now licensed under the GNU Library
6191 General Public License.
6193 *** Changes in GDB-4.7:
6195 * Host/native/target split
6197 GDB has had some major internal surgery to untangle the support for
6198 hosts and remote targets. Now, when you configure GDB for a remote
6199 target, it will no longer load in all of the support for debugging
6200 local programs on the host. When fully completed and tested, this will
6201 ensure that arbitrary host/target combinations are possible.
6203 The primary conceptual shift is to separate the non-portable code in
6204 GDB into three categories. Host specific code is required any time GDB
6205 is compiled on that host, regardless of the target. Target specific
6206 code relates to the peculiarities of the target, but can be compiled on
6207 any host. Native specific code is everything else: it can only be
6208 built when the host and target are the same system. Child process
6209 handling and core file support are two common `native' examples.
6211 GDB's use of /proc for controlling Unix child processes is now cleaner.
6212 It has been split out into a single module under the `target_ops' vector,
6213 plus two native-dependent functions for each system that uses /proc.
6215 * New hosts supported
6217 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6218 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6219 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6221 * New targets supported
6223 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6224 68030 and CPU32 m68030-*-*, m68332-*-*
6226 * New native hosts supported
6228 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6229 (386bsd is not well tested yet)
6230 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6232 * New file formats supported
6234 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6235 supports reading of `a.out.adobe' object files, which are an a.out
6236 format extended with minimal information about multiple sections.
6240 `show copying' is the same as the old `info copying'.
6241 `show warranty' is the same as `info warrantee'.
6242 These were renamed for consistency. The old commands continue to work.
6244 `info handle' is a new alias for `info signals'.
6246 You can now define pre-command hooks, which attach arbitrary command
6247 scripts to any command. The commands in the hook will be executed
6248 prior to the user's command. You can also create a hook which will be
6249 executed whenever the program stops. See gdb.texinfo.
6253 We now deal with Cfront style name mangling, and can even extract type
6254 info from mangled symbols. GDB can automatically figure out which
6255 symbol mangling style your C++ compiler uses.
6257 Calling of methods and virtual functions has been improved as well.
6261 The crash that occured when debugging Sun Ansi-C compiled binaries is
6262 fixed. This was due to mishandling of the extra N_SO stabs output
6265 We also finally got Ultrix 4.2 running in house, and fixed core file
6266 support, with help from a dozen people on the net.
6268 John M. Farrell discovered that the reason that single-stepping was so
6269 slow on all of the Mips based platforms (primarily SGI and DEC) was
6270 that we were trying to demangle and lookup a symbol used for internal
6271 purposes on every instruction that was being stepped through. Changing
6272 the name of that symbol so that it couldn't be mistaken for a C++
6273 mangled symbol sped things up a great deal.
6275 Rich Pixley sped up symbol lookups in general by getting much smarter
6276 about when C++ symbol mangling is necessary. This should make symbol
6277 completion (TAB on the command line) much faster. It's not as fast as
6278 we'd like, but it's significantly faster than gdb-4.6.
6282 A new user controllable variable 'call_scratch_address' can
6283 specify the location of a scratch area to be used when GDB
6284 calls a function in the target. This is necessary because the
6285 usual method of putting the scratch area on the stack does not work
6286 in systems that have separate instruction and data spaces.
6288 We integrated changes to support the 29k UDI (Universal Debugger
6289 Interface), but discovered at the last minute that we didn't have all
6290 of the appropriate copyright paperwork. We are working with AMD to
6291 resolve this, and hope to have it available soon.
6295 We have sped up the remote serial line protocol, especially for targets
6296 with lots of registers. It now supports a new `expedited status' ('T')
6297 message which can be used in place of the existing 'S' status message.
6298 This allows the remote stub to send only the registers that GDB
6299 needs to make a quick decision about single-stepping or conditional
6300 breakpoints, eliminating the need to fetch the entire register set for
6301 each instruction being stepped through.
6303 The GDB remote serial protocol now implements a write-through cache for
6304 registers, only re-reading the registers if the target has run.
6306 There is also a new remote serial stub for SPARC processors. You can
6307 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6308 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6309 processor with a serial port.
6313 Configure.in files have become much easier to read and modify. A new
6314 `table driven' format makes it more obvious what configurations are
6315 supported, and what files each one uses.
6319 There is a new opcodes library which will eventually contain all of the
6320 disassembly routines and opcode tables. At present, it only contains
6321 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6322 disassembler (binutils/objdump) to share these routines.
6324 The libiberty library is now copylefted under the GNU Library General
6325 Public License. This allows more liberal use, and was done so libg++
6326 can use it. This makes no difference to GDB, since the Library License
6327 grants all the rights from the General Public License.
6331 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6332 reference to the stabs symbol info used by the debugger. It is (as far
6333 as we know) the only published document on this fascinating topic. We
6334 encourage you to read it, compare it to the stabs information on your
6335 system, and send improvements on the document in general (to
6336 bug-gdb@prep.ai.mit.edu).
6338 And, of course, many bugs have been fixed.
6341 *** Changes in GDB-4.6:
6343 * Better support for C++ function names
6345 GDB now accepts as input the "demangled form" of C++ overloaded function
6346 names and member function names, and can do command completion on such names
6347 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6348 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6349 Make use of command completion, it is your friend.
6351 GDB also now accepts a variety of C++ mangled symbol formats. They are
6352 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6353 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6354 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6355 for the list of formats.
6357 * G++ symbol mangling problem
6359 Recent versions of gcc have a bug in how they emit debugging information for
6360 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6361 directory) can be applied to gcc to fix the problem. Alternatively, if you
6362 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6363 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6364 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6367 * New 'maintenance' command
6369 All of the commands related to hacking GDB internals have been moved out of
6370 the main command set, and now live behind the 'maintenance' command. This
6371 can also be abbreviated as 'mt'. The following changes were made:
6373 dump-me -> maintenance dump-me
6374 info all-breakpoints -> maintenance info breakpoints
6375 printmsyms -> maintenance print msyms
6376 printobjfiles -> maintenance print objfiles
6377 printpsyms -> maintenance print psymbols
6378 printsyms -> maintenance print symbols
6380 The following commands are new:
6382 maintenance demangle Call internal GDB demangler routine to
6383 demangle a C++ link name and prints the result.
6384 maintenance print type Print a type chain for a given symbol
6386 * Change to .gdbinit file processing
6388 We now read the $HOME/.gdbinit file before processing the argv arguments
6389 (e.g. reading symbol files or core files). This allows global parameters to
6390 be set, which will apply during the symbol reading. The ./.gdbinit is still
6391 read after argv processing.
6393 * New hosts supported
6395 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6397 GNU/Linux support i386-unknown-linux or linux
6399 We are also including code to support the HP/PA running BSD and HPUX. This
6400 is almost guaranteed not to work, as we didn't have time to test or build it
6401 for this release. We are including it so that the more adventurous (or
6402 masochistic) of you can play with it. We also had major problems with the
6403 fact that the compiler that we got from HP doesn't support the -g option.
6406 * New targets supported
6408 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6410 * More smarts about finding #include files
6412 GDB now remembers the compilation directory for all include files, and for
6413 all files from which C is generated (like yacc and lex sources). This
6414 greatly improves GDB's ability to find yacc/lex sources, and include files,
6415 especially if you are debugging your program from a directory different from
6416 the one that contains your sources.
6418 We also fixed a bug which caused difficulty with listing and setting
6419 breakpoints in include files which contain C code. (In the past, you had to
6420 try twice in order to list an include file that you hadn't looked at before.)
6422 * Interesting infernals change
6424 GDB now deals with arbitrary numbers of sections, where the symbols for each
6425 section must be relocated relative to that section's landing place in the
6426 target's address space. This work was needed to support ELF with embedded
6427 stabs used by Solaris-2.0.
6429 * Bug fixes (of course!)
6431 There have been loads of fixes for the following things:
6432 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6433 i960, stabs, DOS(GO32), procfs, etc...
6435 See the ChangeLog for details.
6437 *** Changes in GDB-4.5:
6439 * New machines supported (host and target)
6441 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6443 SGI Irix-4.x mips-sgi-irix4 or iris4
6445 * New malloc package
6447 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6448 Mmalloc is capable of handling mutiple heaps of memory. It is also
6449 capable of saving a heap to a file, and then mapping it back in later.
6450 This can be used to greatly speedup the startup of GDB by using a
6451 pre-parsed symbol table which lives in a mmalloc managed heap. For
6452 more details, please read mmalloc/mmalloc.texi.
6456 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6457 'help info proc' for details.
6459 * MIPS ecoff symbol table format
6461 The code that reads MIPS symbol table format is now supported on all hosts.
6462 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6465 * File name changes for MS-DOS
6467 Many files in the config directories have been renamed to make it easier to
6468 support GDB on MS-DOSe systems (which have very restrictive file name
6469 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6470 environment) is close to working but has some remaining problems. Note
6471 that debugging of DOS programs is not supported, due to limitations
6472 in the ``operating system'', but it can be used to host cross-debugging.
6474 * Cross byte order fixes
6476 Many fixes have been made to support cross debugging of Sparc and MIPS
6477 targets from hosts whose byte order differs.
6479 * New -mapped and -readnow options
6481 If memory-mapped files are available on your system through the 'mmap'
6482 system call, you can use the -mapped option on the `file' or
6483 `symbol-file' commands to cause GDB to write the symbols from your
6484 program into a reusable file. If the program you are debugging is
6485 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6486 Future GDB debugging sessions will notice the presence of this file,
6487 and will quickly map in symbol information from it, rather than reading
6488 the symbol table from the executable program. Using the '-mapped'
6489 option in a GDB `file' or `symbol-file' command has the same effect as
6490 starting GDB with the '-mapped' command-line option.
6492 You can cause GDB to read the entire symbol table immediately by using
6493 the '-readnow' option with any of the commands that load symbol table
6494 information (or on the GDB command line). This makes the command
6495 slower, but makes future operations faster.
6497 The -mapped and -readnow options are typically combined in order to
6498 build a `fred.syms' file that contains complete symbol information.
6499 A simple GDB invocation to do nothing but build a `.syms' file for future
6502 gdb -batch -nx -mapped -readnow programname
6504 The `.syms' file is specific to the host machine on which GDB is run.
6505 It holds an exact image of GDB's internal symbol table. It cannot be
6506 shared across multiple host platforms.
6508 * longjmp() handling
6510 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6511 siglongjmp() without losing control. This feature has not yet been ported to
6512 all systems. It currently works on many 386 platforms, all MIPS-based
6513 platforms (SGI, DECstation, etc), and Sun3/4.
6517 Preliminary work has been put in to support the new Solaris OS from Sun. At
6518 this time, it can control and debug processes, but it is not capable of
6523 As always, many many bug fixes. The major areas were with g++, and mipsread.
6524 People using the MIPS-based platforms should experience fewer mysterious
6525 crashes and trashed symbol tables.
6527 *** Changes in GDB-4.4:
6529 * New machines supported (host and target)
6531 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6533 BSD Reno on Vax vax-dec-bsd
6534 Ultrix on Vax vax-dec-ultrix
6536 * New machines supported (target)
6538 AMD 29000 embedded, using EBMON a29k-none-none
6542 GDB continues to improve its handling of C++. `References' work better.
6543 The demangler has also been improved, and now deals with symbols mangled as
6544 per the Annotated C++ Reference Guide.
6546 GDB also now handles `stabs' symbol information embedded in MIPS
6547 `ecoff' symbol tables. Since the ecoff format was not easily
6548 extensible to handle new languages such as C++, this appeared to be a
6549 good way to put C++ debugging info into MIPS binaries. This option
6550 will be supported in the GNU C compiler, version 2, when it is
6553 * New features for SVR4
6555 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6556 shared libraries. Debugging dynamically linked programs should present
6557 only minor differences from debugging statically linked programs.
6559 The `info proc' command will print out information about any process
6560 on an SVR4 system (including the one you are debugging). At the moment,
6561 it prints the address mappings of the process.
6563 If you bring up GDB on another SVR4 system, please send mail to
6564 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6566 * Better dynamic linking support in SunOS
6568 Reading symbols from shared libraries which contain debugging symbols
6569 now works properly. However, there remain issues such as automatic
6570 skipping of `transfer vector' code during function calls, which
6571 make it harder to debug code in a shared library, than to debug the
6572 same code linked statically.
6576 GDB is now using the latest `getopt' routines from the FSF. This
6577 version accepts the -- prefix for options with long names. GDB will
6578 continue to accept the old forms (-option and +option) as well.
6579 Various single letter abbreviations for options have been explicity
6580 added to the option table so that they won't get overshadowed in the
6581 future by other options that begin with the same letter.
6585 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6586 Many assorted bugs have been handled. Many more remain to be handled.
6587 See the various ChangeLog files (primarily in gdb and bfd) for details.
6590 *** Changes in GDB-4.3:
6592 * New machines supported (host and target)
6594 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6595 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6596 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6598 * Almost SCO Unix support
6600 We had hoped to support:
6601 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6602 (except for core file support), but we discovered very late in the release
6603 that it has problems with process groups that render gdb unusable. Sorry
6604 about that. I encourage people to fix it and post the fixes.
6606 * Preliminary ELF and DWARF support
6608 GDB can read ELF object files on System V Release 4, and can handle
6609 debugging records for C, in DWARF format, in ELF files. This support
6610 is preliminary. If you bring up GDB on another SVR4 system, please
6611 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6616 GDB now uses the latest `readline' library. One user-visible change
6617 is that two tabs will list possible command completions, which previously
6618 required typing M-? (meta-question mark, or ESC ?).
6622 The `stepi' bug that many of you noticed has been squashed.
6623 Many bugs in C++ have been handled. Many more remain to be handled.
6624 See the various ChangeLog files (primarily in gdb and bfd) for details.
6626 * State of the MIPS world (in case you wondered):
6628 GDB can understand the symbol tables emitted by the compilers
6629 supplied by most vendors of MIPS-based machines, including DEC. These
6630 symbol tables are in a format that essentially nobody else uses.
6632 Some versions of gcc come with an assembler post-processor called
6633 mips-tfile. This program is required if you want to do source-level
6634 debugging of gcc-compiled programs. I believe FSF does not ship
6635 mips-tfile with gcc version 1, but it will eventually come with gcc
6638 Debugging of g++ output remains a problem. g++ version 1.xx does not
6639 really support it at all. (If you're lucky, you should be able to get
6640 line numbers and stack traces to work, but no parameters or local
6641 variables.) With some work it should be possible to improve the
6644 When gcc version 2 is released, you will have somewhat better luck.
6645 However, even then you will get confusing results for inheritance and
6648 We will eventually provide full debugging of g++ output on
6649 DECstations. This will probably involve some kind of stabs-in-ecoff
6650 encapulation, but the details have not been worked out yet.
6653 *** Changes in GDB-4.2:
6655 * Improved configuration
6657 Only one copy of `configure' exists now, and it is not self-modifying.
6658 Porting BFD is simpler.
6662 The `step' and `next' commands now only stop at the first instruction
6663 of a source line. This prevents the multiple stops that used to occur
6664 in switch statements, for-loops, etc. `Step' continues to stop if a
6665 function that has debugging information is called within the line.
6669 Lots of small bugs fixed. More remain.
6671 * New host supported (not target)
6673 Intel 386 PC clone running Mach i386-none-mach
6676 *** Changes in GDB-4.1:
6678 * Multiple source language support
6680 GDB now has internal scaffolding to handle several source languages.
6681 It determines the type of each source file from its filename extension,
6682 and will switch expression parsing and number formatting to match the
6683 language of the function in the currently selected stack frame.
6684 You can also specifically set the language to be used, with
6685 `set language c' or `set language modula-2'.
6689 GDB now has preliminary support for the GNU Modula-2 compiler,
6690 currently under development at the State University of New York at
6691 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6692 continue through the fall of 1991 and into 1992.
6694 Other Modula-2 compilers are currently not supported, and attempting to
6695 debug programs compiled with them will likely result in an error as the
6696 symbol table is read. Feel free to work on it, though!
6698 There are hooks in GDB for strict type checking and range checking,
6699 in the `Modula-2 philosophy', but they do not currently work.
6703 GDB can now write to executable and core files (e.g. patch
6704 a variable's value). You must turn this switch on, specify
6705 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6706 by assigning a new value to a variable. Modifications take
6709 * Automatic SunOS shared library reading
6711 When you run your program, GDB automatically determines where its
6712 shared libraries (if any) have been loaded, and reads their symbols.
6713 The `share' command is no longer needed. This also works when
6714 examining core files.
6718 You can specify the number of lines that the `list' command shows.
6721 * New machines supported (host and target)
6723 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6724 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6725 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6727 * New hosts supported (not targets)
6729 IBM RT/PC: romp-ibm-aix or rtpc
6731 * New targets supported (not hosts)
6733 AMD 29000 embedded with COFF a29k-none-coff
6734 AMD 29000 embedded with a.out a29k-none-aout
6735 Ultracomputer remote kernel debug a29k-nyu-kern
6737 * New remote interfaces
6743 *** Changes in GDB-4.0:
6747 Wide output is wrapped at good places to make the output more readable.
6749 Gdb now supports cross-debugging from a host machine of one type to a
6750 target machine of another type. Communication with the target system
6751 is over serial lines. The ``target'' command handles connecting to the
6752 remote system; the ``load'' command will download a program into the
6753 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6754 also supports debugging of realtime processes running under VxWorks,
6755 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6756 stub on the target system.
6758 New CPUs supported include the AMD 29000 and Intel 960.
6760 GDB now reads object files and symbol tables via a ``binary file''
6761 library, which allows a single copy of GDB to debug programs of multiple
6762 object file types such as a.out and coff.
6764 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6765 refcard.dvi and refcard.ps are available to format it).
6768 * Control-Variable user interface simplified
6770 All variables that control the operation of the debugger can be set
6771 by the ``set'' command, and displayed by the ``show'' command.
6773 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6774 ``Show prompt'' produces the response:
6775 Gdb's prompt is new-gdb=>.
6777 What follows are the NEW set commands. The command ``help set'' will
6778 print a complete list of old and new set commands. ``help set FOO''
6779 will give a longer description of the variable FOO. ``show'' will show
6780 all of the variable descriptions and their current settings.
6782 confirm on/off: Enables warning questions for operations that are
6783 hard to recover from, e.g. rerunning the program while
6784 it is already running. Default is ON.
6786 editing on/off: Enables EMACS style command line editing
6787 of input. Previous lines can be recalled with
6788 control-P, the current line can be edited with control-B,
6789 you can search for commands with control-R, etc.
6792 history filename NAME: NAME is where the gdb command history
6793 will be stored. The default is .gdb_history,
6794 or the value of the environment variable
6797 history size N: The size, in commands, of the command history. The
6798 default is 256, or the value of the environment variable
6801 history save on/off: If this value is set to ON, the history file will
6802 be saved after exiting gdb. If set to OFF, the
6803 file will not be saved. The default is OFF.
6805 history expansion on/off: If this value is set to ON, then csh-like
6806 history expansion will be performed on
6807 command line input. The default is OFF.
6809 radix N: Sets the default radix for input and output. It can be set
6810 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6811 in the current radix, so "set radix 10" is always a no-op.
6813 height N: This integer value is the number of lines on a page. Default
6814 is 24, the current `stty rows'' setting, or the ``li#''
6815 setting from the termcap entry matching the environment
6818 width N: This integer value is the number of characters on a line.
6819 Default is 80, the current `stty cols'' setting, or the ``co#''
6820 setting from the termcap entry matching the environment
6823 Note: ``set screensize'' is obsolete. Use ``set height'' and
6824 ``set width'' instead.
6826 print address on/off: Print memory addresses in various command displays,
6827 such as stack traces and structure values. Gdb looks
6828 more ``symbolic'' if you turn this off; it looks more
6829 ``machine level'' with it on. Default is ON.
6831 print array on/off: Prettyprint arrays. New convenient format! Default
6834 print demangle on/off: Print C++ symbols in "source" form if on,
6837 print asm-demangle on/off: Same, for assembler level printouts
6840 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6843 * Support for Epoch Environment.
6845 The epoch environment is a version of Emacs v18 with windowing. One
6846 new command, ``inspect'', is identical to ``print'', except that if you
6847 are running in the epoch environment, the value is printed in its own
6851 * Support for Shared Libraries
6853 GDB can now debug programs and core files that use SunOS shared libraries.
6854 Symbols from a shared library cannot be referenced
6855 before the shared library has been linked with the program (this
6856 happens after you type ``run'' and before the function main() is entered).
6857 At any time after this linking (including when examining core files
6858 from dynamically linked programs), gdb reads the symbols from each
6859 shared library when you type the ``sharedlibrary'' command.
6860 It can be abbreviated ``share''.
6862 sharedlibrary REGEXP: Load shared object library symbols for files
6863 matching a unix regular expression. No argument
6864 indicates to load symbols for all shared libraries.
6866 info sharedlibrary: Status of loaded shared libraries.
6871 A watchpoint stops execution of a program whenever the value of an
6872 expression changes. Checking for this slows down execution
6873 tremendously whenever you are in the scope of the expression, but is
6874 quite useful for catching tough ``bit-spreader'' or pointer misuse
6875 problems. Some machines such as the 386 have hardware for doing this
6876 more quickly, and future versions of gdb will use this hardware.
6878 watch EXP: Set a watchpoint (breakpoint) for an expression.
6880 info watchpoints: Information about your watchpoints.
6882 delete N: Deletes watchpoint number N (same as breakpoints).
6883 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6884 enable N: Re-enables watchpoint number N (same as breakpoints).
6887 * C++ multiple inheritance
6889 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6892 * C++ exception handling
6894 Gdb now supports limited C++ exception handling. Besides the existing
6895 ability to breakpoint on an exception handler, gdb can breakpoint on
6896 the raising of an exception (before the stack is peeled back to the
6899 catch FOO: If there is a FOO exception handler in the dynamic scope,
6900 set a breakpoint to catch exceptions which may be raised there.
6901 Multiple exceptions (``catch foo bar baz'') may be caught.
6903 info catch: Lists all exceptions which may be caught in the
6904 current stack frame.
6907 * Minor command changes
6909 The command ``call func (arg, arg, ...)'' now acts like the print
6910 command, except it does not print or save a value if the function's result
6911 is void. This is similar to dbx usage.
6913 The ``up'' and ``down'' commands now always print the frame they end up
6914 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6915 frames without printing.
6917 * New directory command
6919 'dir' now adds directories to the FRONT of the source search path.
6920 The path starts off empty. Source files that contain debug information
6921 about the directory in which they were compiled can be found even
6922 with an empty path; Sun CC and GCC include this information. If GDB can't
6923 find your source file in the current directory, type "dir .".
6925 * Configuring GDB for compilation
6927 For normal use, type ``./configure host''. See README or gdb.texinfo
6930 GDB now handles cross debugging. If you are remotely debugging between
6931 two different machines, type ``./configure host -target=targ''.
6932 Host is the machine where GDB will run; targ is the machine
6933 where the program that you are debugging will run.