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 * Breakpoints on C++ functions are now set on all scopes by default
63 By default, breakpoints on functions/methods are now interpreted as
64 specifying all functions with the given name ignoring missing
65 leading scopes (namespaces and classes).
67 For example, assuming a C++ program with symbols named:
72 both commands "break func()" and "break B::func()" set a breakpoint
75 You can use the new flag "-qualified" to override this. This makes
76 GDB interpret the specified function name as a complete
77 fully-qualified name instead. For example, using the same C++
78 program, the "break -q B::func" command sets a breakpoint on
81 * Breakpoints on functions marked with C++ ABI tags
83 GDB can now set breakpoints on functions marked with C++ ABI tags
84 (e.g., [abi:cxx11]). See here for a description of ABI tags:
85 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
87 Functions with a C++11 abi tag are demangled/displayed like this:
89 function[abi:cxx11](int)
92 You can now set a breakpoint on such functions simply as if they had
97 Or if you need to disambiguate between tags, like:
99 (gdb) b function[abi:other_tag](int)
101 Tab completion was adjusted accordingly as well.
105 ** New events gdb.new_inferior, gdb.inferior_deleted, and
106 gdb.new_thread are emitted. See the manual for further
107 description of these.
109 ** A new command, "rbreak" has been added to the Python API. This
110 command allows the setting of a large number of breakpoints via a
111 regex pattern in Python. See the manual for further details.
113 * New features in the GDB remote stub, GDBserver
115 ** GDBserver is now able to start inferior processes with a
116 specified initial working directory.
118 The user can set the desired working directory to be used from
119 GDB using the new "set cwd" command.
121 ** New "--selftest" command line option runs some GDBserver self
122 tests. These self tests are disabled in releases.
124 ** On Unix systems, GDBserver now does globbing expansion and variable
125 substitution in inferior command line arguments.
127 This is done by starting inferiors using a shell, like GDB does.
128 See "set startup-with-shell" in the user manual for how to disable
129 this from GDB when using "target extended-remote". When using
130 "target remote", you can disable the startup with shell by using the
131 new "--no-startup-with-shell" GDBserver command line option.
133 ** On Unix systems, GDBserver now supports receiving environment
134 variables that are to be set or unset from GDB. These variables
135 will affect the environment to be passed to the inferior.
137 * When catching an Ada exception raised with a message, GDB now prints
138 the message in the catchpoint hit notification. In GDB/MI mode, that
139 information is provided as an extra field named "exception-message"
140 in the *stopped notification.
144 QEnvironmentHexEncoded
145 Inform GDBserver of an environment variable that is to be passed to
146 the inferior when starting it.
149 Inform GDBserver of an environment variable that is to be unset
150 before starting the remote inferior.
153 Inform GDBserver that the environment should be reset (i.e.,
154 user-set environment variables should be unset).
157 Indicates whether the inferior must be started with a shell or not.
160 Tell GDBserver that the inferior to be started should use a specific
163 * The "maintenance print c-tdesc" command now takes an optional
164 argument which is the file name of XML target description.
166 * The "maintenance selftest" command now takes an optional argument to
167 filter the tests to be run.
169 * The "enable", and "disable" commands now accept a range of
170 breakpoint locations, e.g. "enable 1.3-5".
175 Set and show the current working directory for the inferior.
178 Set and show compilation command used for compiling and injecting code
179 with the 'compile' commands.
181 set debug separate-debug-file
182 show debug separate-debug-file
183 Control the display of debug output about separate debug file search.
186 List the registered selftests.
189 Start the debugged program stopping at the first instruction.
191 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
194 * Safer/improved support for debugging with no debug info
196 GDB no longer assumes functions with no debug information return
199 This means that GDB now refuses to call such functions unless you
200 tell it the function's type, by either casting the call to the
201 declared return type, or by casting the function to a function
202 pointer of the right type, and calling that:
204 (gdb) p getenv ("PATH")
205 'getenv' has unknown return type; cast the call to its declared return type
206 (gdb) p (char *) getenv ("PATH")
207 $1 = 0x7fffffffe "/usr/local/bin:/"...
208 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
209 $2 = 0x7fffffffe "/usr/local/bin:/"...
211 Similarly, GDB no longer assumes that global variables with no debug
212 info have type 'int', and refuses to print the variable's value
213 unless you tell it the variable's type:
216 'var' has unknown type; cast it to its declared type
220 * New native configurations
222 FreeBSD/aarch64 aarch64*-*-freebsd*
223 FreeBSD/arm arm*-*-freebsd*
227 FreeBSD/aarch64 aarch64*-*-freebsd*
228 FreeBSD/arm arm*-*-freebsd*
230 * Removed targets and native configurations
232 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
234 *** Changes in GDB 8.0
236 * GDB now supports access to the PKU register on GNU/Linux. The register is
237 added by the Memory Protection Keys for Userspace feature which will be
238 available in future Intel CPUs.
240 * GDB now supports C++11 rvalue references.
244 ** New functions to start, stop and access a running btrace recording.
245 ** Rvalue references are now supported in gdb.Type.
247 * GDB now supports recording and replaying rdrand and rdseed Intel 64
250 * Building GDB and GDBserver now requires a C++11 compiler.
252 For example, GCC 4.8 or later.
254 It is no longer possible to build GDB or GDBserver with a C
255 compiler. The --disable-build-with-cxx configure option has been
258 * Building GDB and GDBserver now requires GNU make >= 3.81.
260 It is no longer supported to build GDB or GDBserver with another
261 implementation of the make program or an earlier version of GNU make.
263 * Native debugging on MS-Windows supports command-line redirection
265 Command-line arguments used for starting programs on MS-Windows can
266 now include redirection symbols supported by native Windows shells,
267 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
268 as "run", "start", and "set args", as well as the corresponding MI
271 * Support for thread names on MS-Windows.
273 GDB now catches and handles the special exception that programs
274 running on MS-Windows use to assign names to threads in the
277 * Support for Java programs compiled with gcj has been removed.
279 * User commands now accept an unlimited number of arguments.
280 Previously, only up to 10 was accepted.
282 * The "eval" command now expands user-defined command arguments.
284 This makes it easier to process a variable number of arguments:
289 eval "print $arg%d", $i
294 * Target descriptions can now describe registers for sparc32 and sparc64.
296 * GDB now supports DWARF version 5 (debug information format).
297 Its .debug_names index is not yet supported.
299 * New native configurations
301 FreeBSD/mips mips*-*-freebsd
305 Synopsys ARC arc*-*-elf32
306 FreeBSD/mips mips*-*-freebsd
308 * Removed targets and native configurations
310 Alpha running FreeBSD alpha*-*-freebsd*
311 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
316 Erases all the flash memory regions reported by the target.
318 maint print arc arc-instruction address
319 Print internal disassembler information about instruction at a given address.
323 set disassembler-options
324 show disassembler-options
325 Controls the passing of target specific information to the disassembler.
326 If it is necessary to specify more than one disassembler option then
327 multiple options can be placed together into a comma separated list.
328 The default value is the empty string. Currently, the only supported
329 targets are ARM, PowerPC and S/390.
334 Erases all the flash memory regions reported by the target. This is
335 equivalent to the CLI command flash-erase.
337 -file-list-shared-libraries
338 List the shared libraries in the program. This is
339 equivalent to the CLI command "info shared".
341 *** Changes in GDB 7.12
343 * GDB and GDBserver now build with a C++ compiler by default.
345 The --enable-build-with-cxx configure option is now enabled by
346 default. One must now explicitly configure with
347 --disable-build-with-cxx in order to build with a C compiler. This
348 option will be removed in a future release.
350 * GDBserver now supports recording btrace without maintaining an active
353 * GDB now supports a negative repeat count in the 'x' command to examine
354 memory backward from the given address. For example:
357 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
358 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
359 (gdb) x/-5i 0x0000000000400580
360 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
361 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
362 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
363 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
364 0x40057b <main(int, char**)+25>:
365 callq 0x400536 <Func1(int, char const*)>
367 * Fortran: Support structures with fields of dynamic types and
368 arrays of dynamic types.
370 * The symbol dumping maintenance commands have new syntax.
371 maint print symbols [-pc address] [--] [filename]
372 maint print symbols [-objfile objfile] [-source source] [--] [filename]
373 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
374 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
375 maint print msymbols [-objfile objfile] [--] [filename]
377 * GDB now supports multibit bitfields and enums in target register
380 * New Python-based convenience function $_as_string(val), which returns
381 the textual representation of a value. This function is especially
382 useful to obtain the text label of an enum value.
384 * Intel MPX bound violation handling.
386 Segmentation faults caused by a Intel MPX boundary violation
387 now display the kind of violation (upper or lower), the memory
388 address accessed and the memory bounds, along with the usual
389 signal received and code location.
393 Program received signal SIGSEGV, Segmentation fault
394 Upper bound violation while accessing address 0x7fffffffc3b3
395 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
396 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
398 * Rust language support.
399 GDB now supports debugging programs written in the Rust programming
400 language. See https://www.rust-lang.org/ for more information about
403 * Support for running interpreters on specified input/output devices
405 GDB now supports a new mechanism that allows frontends to provide
406 fully featured GDB console views, as a better alternative to
407 building such views on top of the "-interpreter-exec console"
408 command. See the new "new-ui" command below. With that command,
409 frontends can now start GDB in the traditional command-line mode
410 running in an embedded terminal emulator widget, and create a
411 separate MI interpreter running on a specified i/o device. In this
412 way, GDB handles line editing, history, tab completion, etc. in the
413 console all by itself, and the GUI uses the separate MI interpreter
414 for its own control and synchronization, invisible to the command
417 * The "catch syscall" command catches groups of related syscalls.
419 The "catch syscall" command now supports catching a group of related
420 syscalls using the 'group:' or 'g:' prefix.
425 skip -gfile file-glob-pattern
426 skip -function function
427 skip -rfunction regular-expression
428 A generalized form of the skip command, with new support for
429 glob-style file names and regular expressions for function names.
430 Additionally, a file spec and a function spec may now be combined.
432 maint info line-table REGEXP
433 Display the contents of GDB's internal line table data struture.
436 Run any GDB unit tests that were compiled in.
439 Start a new user interface instance running INTERP as interpreter,
440 using the TTY file for input/output.
444 ** gdb.Breakpoint objects have a new attribute "pending", which
445 indicates whether the breakpoint is pending.
446 ** Three new breakpoint-related events have been added:
447 gdb.breakpoint_created, gdb.breakpoint_modified, and
448 gdb.breakpoint_deleted.
451 Signal ("set") the given MS-Windows event object. This is used in
452 conjunction with the Windows JIT debugging (AeDebug) support, where
453 the OS suspends a crashing process until a debugger can attach to
454 it. Resuming the crashing process, in order to debug it, is done by
457 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
458 was added in GDBserver, including JIT compiling fast tracepoint's
459 conditional expression bytecode into native code.
461 * Support for various remote target protocols and ROM monitors has
464 target m32rsdi Remote M32R debugging over SDI
465 target mips MIPS remote debugging protocol
466 target pmon PMON ROM monitor
467 target ddb NEC's DDB variant of PMON for Vr4300
468 target rockhopper NEC RockHopper variant of PMON
469 target lsi LSI variant of PMO
471 * Support for tracepoints and fast tracepoints on powerpc-linux,
472 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
473 including JIT compiling fast tracepoint's conditional expression
474 bytecode into native code.
476 * MI async record =record-started now includes the method and format used for
477 recording. For example:
479 =record-started,thread-group="i1",method="btrace",format="bts"
481 * MI async record =thread-selected now includes the frame field. For example:
483 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
487 Andes NDS32 nds32*-*-elf
489 *** Changes in GDB 7.11
491 * GDB now supports debugging kernel-based threads on FreeBSD.
493 * Per-inferior thread numbers
495 Thread numbers are now per inferior instead of global. If you're
496 debugging multiple inferiors, GDB displays thread IDs using a
497 qualified INF_NUM.THR_NUM form. For example:
501 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
502 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
503 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
504 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
506 As consequence, thread numbers as visible in the $_thread
507 convenience variable and in Python's InferiorThread.num attribute
508 are no longer unique between inferiors.
510 GDB now maintains a second thread ID per thread, referred to as the
511 global thread ID, which is the new equivalent of thread numbers in
512 previous releases. See also $_gthread below.
514 For backwards compatibility, MI's thread IDs always refer to global
517 * Commands that accept thread IDs now accept the qualified
518 INF_NUM.THR_NUM form as well. For example:
521 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
524 * In commands that accept a list of thread IDs, you can now refer to
525 all threads of an inferior using a star wildcard. GDB accepts
526 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
527 refer to all threads of the current inferior. For example, "info
530 * You can use "info threads -gid" to display the global thread ID of
533 * The new convenience variable $_gthread holds the global number of
536 * The new convenience variable $_inferior holds the number of the
539 * GDB now displays the ID and name of the thread that hit a breakpoint
540 or received a signal, if your program is multi-threaded. For
543 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
544 Thread 1 "main" received signal SIGINT, Interrupt.
546 * Record btrace now supports non-stop mode.
548 * Support for tracepoints on aarch64-linux was added in GDBserver.
550 * The 'record instruction-history' command now indicates speculative execution
551 when using the Intel Processor Trace recording format.
553 * GDB now allows users to specify explicit locations, bypassing
554 the linespec parser. This feature is also available to GDB/MI
557 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
558 GDB now is able to debug both AArch64 applications and ARM applications
561 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
562 including JIT compiling fast tracepoint's conditional expression bytecode
565 * GDB now supports displaced stepping on AArch64 GNU/Linux.
567 * "info threads", "info inferiors", "info display", "info checkpoints"
568 and "maint info program-spaces" now list the corresponding items in
569 ascending ID order, for consistency with all other "info" commands.
571 * In Ada, the overloads selection menu has been enhanced to display the
572 parameter types and the return types for the matching overloaded subprograms.
576 maint set target-non-stop (on|off|auto)
577 maint show target-non-stop
578 Control whether GDB targets always operate in non-stop mode even if
579 "set non-stop" is "off". The default is "auto", meaning non-stop
580 mode is enabled if supported by the target.
582 maint set bfd-sharing
583 maint show bfd-sharing
584 Control the reuse of bfd objects.
588 Control display of debugging info regarding bfd caching.
592 Control display of debugging info regarding FreeBSD threads.
594 set remote multiprocess-extensions-packet
595 show remote multiprocess-extensions-packet
596 Set/show the use of the remote protocol multiprocess extensions.
598 set remote thread-events
599 show remote thread-events
600 Set/show the use of thread create/exit events.
602 set ada print-signatures on|off
603 show ada print-signatures"
604 Control whether parameter types and return types are displayed in overloads
605 selection menus. It is activaled (@code{on}) by default.
609 Controls the maximum size of memory, in bytes, that GDB will
610 allocate for value contents. Prevents incorrect programs from
611 causing GDB to allocate overly large buffers. Default is 64k.
613 * The "disassemble" command accepts a new modifier: /s.
614 It prints mixed source+disassembly like /m with two differences:
615 - disassembled instructions are now printed in program order, and
616 - and source for all relevant files is now printed.
617 The "/m" option is now considered deprecated: its "source-centric"
618 output hasn't proved useful in practice.
620 * The "record instruction-history" command accepts a new modifier: /s.
621 It behaves exactly like /m and prints mixed source+disassembly.
623 * The "set scheduler-locking" command supports a new mode "replay".
624 It behaves like "off" in record mode and like "on" in replay mode.
626 * Support for various ROM monitors has been removed:
628 target dbug dBUG ROM monitor for Motorola ColdFire
629 target picobug Motorola picobug monitor
630 target dink32 DINK32 ROM monitor for PowerPC
631 target m32r Renesas M32R/D ROM monitor
632 target mon2000 mon2000 ROM monitor
633 target ppcbug PPCBUG ROM monitor for PowerPC
635 * Support for reading/writing memory and extracting values on architectures
636 whose memory is addressable in units of any integral multiple of 8 bits.
641 Indicates that an exec system call was executed.
643 exec-events feature in qSupported
644 The qSupported packet allows GDB to request support for exec
645 events using the new 'gdbfeature' exec-event, and the qSupported
646 response can contain the corresponding 'stubfeature'. Set and
647 show commands can be used to display whether these features are enabled.
650 Equivalent to interrupting with the ^C character, but works in
653 thread created stop reason (T05 create:...)
654 Indicates that the thread was just created and is stopped at entry.
656 thread exit stop reply (w exitcode;tid)
657 Indicates that the thread has terminated.
660 Enables/disables thread create and exit event reporting. For
661 example, this is used in non-stop mode when GDB stops a set of
662 threads and synchronously waits for the their corresponding stop
663 replies. Without exit events, if one of the threads exits, GDB
664 would hang forever not knowing that it should no longer expect a
665 stop for that same thread.
668 Indicates that there are no resumed threads left in the target (all
669 threads are stopped). The remote stub reports support for this stop
670 reply to GDB's qSupported query.
673 Enables/disables catching syscalls from the inferior process.
674 The remote stub reports support for this packet to GDB's qSupported query.
676 syscall_entry stop reason
677 Indicates that a syscall was just called.
679 syscall_return stop reason
680 Indicates that a syscall just returned.
682 * Extended-remote exec events
684 ** GDB now has support for exec events on extended-remote Linux targets.
685 For such targets with Linux kernels 2.5.46 and later, this enables
686 follow-exec-mode and exec catchpoints.
688 set remote exec-event-feature-packet
689 show remote exec-event-feature-packet
690 Set/show the use of the remote exec event feature.
692 * Thread names in remote protocol
694 The reply to qXfer:threads:read may now include a name attribute for each
697 * Target remote mode fork and exec events
699 ** GDB now has support for fork and exec events on target remote mode
700 Linux targets. For such targets with Linux kernels 2.5.46 and later,
701 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
702 fork and exec catchpoints.
704 * Remote syscall events
706 ** GDB now has support for catch syscall on remote Linux targets,
707 currently enabled on x86/x86_64 architectures.
709 set remote catch-syscall-packet
710 show remote catch-syscall-packet
711 Set/show the use of the remote catch syscall feature.
715 ** The -var-set-format command now accepts the zero-hexadecimal
716 format. It outputs data in hexadecimal format with zero-padding on the
721 ** gdb.InferiorThread objects have a new attribute "global_num",
722 which refers to the thread's global thread ID. The existing
723 "num" attribute now refers to the thread's per-inferior number.
724 See "Per-inferior thread numbers" above.
725 ** gdb.InferiorThread objects have a new attribute "inferior", which
726 is the Inferior object the thread belongs to.
728 *** Changes in GDB 7.10
730 * Support for process record-replay and reverse debugging on aarch64*-linux*
731 targets has been added. GDB now supports recording of A64 instruction set
732 including advance SIMD instructions.
734 * Support for Sun's version of the "stabs" debug file format has been removed.
736 * GDB now honors the content of the file /proc/PID/coredump_filter
737 (PID is the process ID) on GNU/Linux systems. This file can be used
738 to specify the types of memory mappings that will be included in a
739 corefile. For more information, please refer to the manual page of
740 "core(5)". GDB also has a new command: "set use-coredump-filter
741 on|off". It allows to set whether GDB will read the content of the
742 /proc/PID/coredump_filter file when generating a corefile.
744 * The "info os" command on GNU/Linux can now display information on
746 "info os cpus" Listing of all cpus/cores on the system
748 * GDB has two new commands: "set serial parity odd|even|none" and
749 "show serial parity". These allows to set or show parity for the
752 * The "info source" command now displays the producer string if it was
753 present in the debug info. This typically includes the compiler version
754 and may include things like its command line arguments.
756 * The "info dll", an alias of the "info sharedlibrary" command,
757 is now available on all platforms.
759 * Directory names supplied to the "set sysroot" commands may be
760 prefixed with "target:" to tell GDB to access shared libraries from
761 the target system, be it local or remote. This replaces the prefix
762 "remote:". The default sysroot has been changed from "" to
763 "target:". "remote:" is automatically converted to "target:" for
764 backward compatibility.
766 * The system root specified by "set sysroot" will be prepended to the
767 filename of the main executable (if reported to GDB as absolute by
768 the operating system) when starting processes remotely, and when
769 attaching to already-running local or remote processes.
771 * GDB now supports automatic location and retrieval of executable
772 files from remote targets. Remote debugging can now be initiated
773 using only a "target remote" or "target extended-remote" command
774 (no "set sysroot" or "file" commands are required). See "New remote
777 * The "dump" command now supports verilog hex format.
779 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
781 * On GNU/Linux, GDB and gdbserver are now able to access executable
782 and shared library files without a "set sysroot" command when
783 attaching to processes running in different mount namespaces from
784 the debugger. This makes it possible to attach to processes in
785 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
786 See "New remote packets" below.
788 * The "tui reg" command now provides completion for all of the
789 available register groups, including target specific groups.
791 * The HISTSIZE environment variable is no longer read when determining
792 the size of GDB's command history. GDB now instead reads the dedicated
793 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
794 disables truncation of command history. Non-numeric values of GDBHISTSIZE
799 ** Memory ports can now be unbuffered.
803 ** gdb.Objfile objects have a new attribute "username",
804 which is the name of the objfile as specified by the user,
805 without, for example, resolving symlinks.
806 ** You can now write frame unwinders in Python.
807 ** gdb.Type objects have a new method "optimized_out",
808 returning optimized out gdb.Value instance of this type.
809 ** gdb.Value objects have new methods "reference_value" and
810 "const_value" which return a reference to the value and a
811 "const" version of the value respectively.
815 maint print symbol-cache
816 Print the contents of the symbol cache.
818 maint print symbol-cache-statistics
819 Print statistics of symbol cache usage.
821 maint flush-symbol-cache
822 Flush the contents of the symbol cache.
826 Start branch trace recording using Branch Trace Store (BTS) format.
829 Evaluate expression by using the compiler and print result.
833 Explicit commands for enabling and disabling tui mode.
836 set mpx bound on i386 and amd64
837 Support for bound table investigation on Intel MPX enabled applications.
841 Start branch trace recording using Intel Processor Trace format.
844 Print information about branch tracing internals.
846 maint btrace packet-history
847 Print the raw branch tracing data.
849 maint btrace clear-packet-history
850 Discard the stored raw branch tracing data.
853 Discard all branch tracing data. It will be fetched and processed
854 anew by the next "record" command.
859 Renamed from "set debug dwarf2-die".
861 Renamed from "show debug dwarf2-die".
864 Renamed from "set debug dwarf2-read".
865 show debug dwarf-read
866 Renamed from "show debug dwarf2-read".
868 maint set dwarf always-disassemble
869 Renamed from "maint set dwarf2 always-disassemble".
870 maint show dwarf always-disassemble
871 Renamed from "maint show dwarf2 always-disassemble".
873 maint set dwarf max-cache-age
874 Renamed from "maint set dwarf2 max-cache-age".
875 maint show dwarf max-cache-age
876 Renamed from "maint show dwarf2 max-cache-age".
879 show debug dwarf-line
880 Control display of debugging info regarding DWARF line processing.
884 Set the maximum number of candidates to be considered during
885 completion. The default value is 200. This limit allows GDB
886 to avoid generating large completion lists, the computation of
887 which can cause the debugger to become temporarily unresponsive.
889 set history remove-duplicates
890 show history remove-duplicates
891 Control the removal of duplicate history entries.
893 maint set symbol-cache-size
894 maint show symbol-cache-size
895 Control the size of the symbol cache.
897 set|show record btrace bts buffer-size
898 Set and show the size of the ring buffer used for branch tracing in
900 The obtained size may differ from the requested size. Use "info
901 record" to see the obtained buffer size.
903 set debug linux-namespaces
904 show debug linux-namespaces
905 Control display of debugging info regarding Linux namespaces.
907 set|show record btrace pt buffer-size
908 Set and show the size of the ring buffer used for branch tracing in
909 Intel Processor Trace format.
910 The obtained size may differ from the requested size. Use "info
911 record" to see the obtained buffer size.
913 maint set|show btrace pt skip-pad
914 Set and show whether PAD packets are skipped when computing the
917 * The command 'thread apply all' can now support new option '-ascending'
918 to call its specified command for all threads in ascending order.
920 * Python/Guile scripting
922 ** GDB now supports auto-loading of Python/Guile scripts contained in the
923 special section named `.debug_gdb_scripts'.
927 qXfer:btrace-conf:read
928 Return the branch trace configuration for the current thread.
930 Qbtrace-conf:bts:size
931 Set the requested ring buffer size for branch tracing in BTS format.
934 Enable Intel Procesor Trace-based branch tracing for the current
935 process. The remote stub reports support for this packet to GDB's
939 Set the requested ring buffer size for branch tracing in Intel Processor
943 Indicates a memory breakpoint instruction was executed, irrespective
944 of whether it was GDB that planted the breakpoint or the breakpoint
945 is hardcoded in the program. This is required for correct non-stop
949 Indicates the target stopped for a hardware breakpoint. This is
950 required for correct non-stop mode operation.
953 Return information about files on the remote system.
956 Return the full absolute name of the file that was executed to
957 create a process running on the remote system.
960 Select the filesystem on which vFile: operations with filename
961 arguments will operate. This is required for GDB to be able to
962 access files on remote targets where the remote stub does not
963 share a common filesystem with the inferior(s).
966 Indicates that a fork system call was executed.
969 Indicates that a vfork system call was executed.
971 vforkdone stop reason
972 Indicates that a vfork child of the specified process has executed
973 an exec or exit, allowing the vfork parent to resume execution.
975 fork-events and vfork-events features in qSupported
976 The qSupported packet allows GDB to request support for fork and
977 vfork events using new 'gdbfeatures' fork-events and vfork-events,
978 and the qSupported response can contain the corresponding
979 'stubfeatures'. Set and show commands can be used to display
980 whether these features are enabled.
982 * Extended-remote fork events
984 ** GDB now has support for fork events on extended-remote Linux
985 targets. For targets with Linux kernels 2.5.60 and later, this
986 enables follow-fork-mode and detach-on-fork for both fork and
987 vfork, as well as fork and vfork catchpoints.
989 * The info record command now shows the recording format and the
990 branch tracing configuration for the current thread when using
991 the btrace record target.
992 For the BTS format, it shows the ring buffer size.
994 * GDB now has support for DTrace USDT (Userland Static Defined
995 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
997 * GDB now supports access to vector registers on S/390 GNU/Linux
1000 * Removed command line options
1002 -xdb HP-UX XDB compatibility mode.
1004 * Removed targets and native configurations
1006 HP/PA running HP-UX hppa*-*-hpux*
1007 Itanium running HP-UX ia64-*-hpux*
1009 * New configure options
1012 This configure option allows the user to build GDB with support for
1013 Intel Processor Trace (default: auto). This requires libipt.
1015 --with-libipt-prefix=PATH
1016 Specify the path to the version of libipt that GDB should use.
1017 $PATH/include should contain the intel-pt.h header and
1018 $PATH/lib should contain the libipt.so library.
1020 *** Changes in GDB 7.9.1
1024 ** Xmethods can now specify a result type.
1026 *** Changes in GDB 7.9
1028 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1032 ** You can now access frame registers from Python scripts.
1033 ** New attribute 'producer' for gdb.Symtab objects.
1034 ** gdb.Objfile objects have a new attribute "progspace",
1035 which is the gdb.Progspace object of the containing program space.
1036 ** gdb.Objfile objects have a new attribute "owner".
1037 ** gdb.Objfile objects have a new attribute "build_id",
1038 which is the build ID generated when the file was built.
1039 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1040 ** A new event "gdb.clear_objfiles" has been added, triggered when
1041 selecting a new file to debug.
1042 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1043 ** New function gdb.lookup_objfile.
1045 New events which are triggered when GDB modifies the state of the
1048 ** gdb.events.inferior_call_pre: Function call is about to be made.
1049 ** gdb.events.inferior_call_post: Function call has just been made.
1050 ** gdb.events.memory_changed: A memory location has been altered.
1051 ** gdb.events.register_changed: A register has been altered.
1053 * New Python-based convenience functions:
1055 ** $_caller_is(name [, number_of_frames])
1056 ** $_caller_matches(regexp [, number_of_frames])
1057 ** $_any_caller_is(name [, number_of_frames])
1058 ** $_any_caller_matches(regexp [, number_of_frames])
1060 * GDB now supports the compilation and injection of source code into
1061 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1062 to compile the source code to object code, and if successful, inject
1063 and execute that code within the current context of the inferior.
1064 Currently the C language is supported. The commands used to
1065 interface with this new feature are:
1067 compile code [-raw|-r] [--] [source code]
1068 compile file [-raw|-r] filename
1072 demangle [-l language] [--] name
1073 Demangle "name" in the specified language, or the current language
1074 if elided. This command is renamed from the "maint demangle" command.
1075 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1076 as "maint demangler-warning".
1078 queue-signal signal-name-or-number
1079 Queue a signal to be delivered to the thread when it is resumed.
1081 add-auto-load-scripts-directory directory
1082 Add entries to the list of directories from which to load auto-loaded
1085 maint print user-registers
1086 List all currently available "user" registers.
1088 compile code [-r|-raw] [--] [source code]
1089 Compile, inject, and execute in the inferior the executable object
1090 code produced by compiling the provided source code.
1092 compile file [-r|-raw] filename
1093 Compile and inject into the inferior the executable object code
1094 produced by compiling the source code stored in the filename
1097 * On resume, GDB now always passes the signal the program had stopped
1098 for to the thread the signal was sent to, even if the user changed
1099 threads before resuming. Previously GDB would often (but not
1100 always) deliver the signal to the thread that happens to be current
1103 * Conversely, the "signal" command now consistently delivers the
1104 requested signal to the current thread. GDB now asks for
1105 confirmation if the program had stopped for a signal and the user
1106 switched threads meanwhile.
1108 * "breakpoint always-inserted" modes "off" and "auto" merged.
1110 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1111 won't remove breakpoints from the target until all threads stop,
1112 even in non-stop mode. The "auto" mode has been removed, and "off"
1113 is now the default mode.
1117 set debug symbol-lookup
1118 show debug symbol-lookup
1119 Control display of debugging info regarding symbol lookup.
1123 ** The -list-thread-groups command outputs an exit-code field for
1124 inferiors that have exited.
1128 MIPS SDE mips*-sde*-elf*
1132 Support for these obsolete configurations has been removed.
1134 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1135 SGI Irix-5.x mips-*-irix5*
1136 SGI Irix-6.x mips-*-irix6*
1137 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1138 VAX running Ultrix vax-*-ultrix*
1140 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1141 and "assf"), have been removed. Use the "sharedlibrary" command, or
1142 its alias "share", instead.
1144 *** Changes in GDB 7.8
1146 * New command line options
1149 This is an alias for the --data-directory option.
1151 * GDB supports printing and modifying of variable length automatic arrays
1152 as specified in ISO C99.
1154 * The ARM simulator now supports instruction level tracing
1155 with or without disassembly.
1159 GDB now has support for scripting using Guile. Whether this is
1160 available is determined at configure time.
1161 Guile version 2.0 or greater is required.
1162 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1164 * New commands (for set/show, see "New options" below)
1168 Invoke CODE by passing it to the Guile interpreter.
1172 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1174 info auto-load guile-scripts [regexp]
1175 Print the list of automatically loaded Guile scripts.
1177 * The source command is now capable of sourcing Guile scripts.
1178 This feature is dependent on the debugger being built with Guile support.
1182 set print symbol-loading (off|brief|full)
1183 show print symbol-loading
1184 Control whether to print informational messages when loading symbol
1185 information for a file. The default is "full", but when debugging
1186 programs with large numbers of shared libraries the amount of output
1187 becomes less useful.
1189 set guile print-stack (none|message|full)
1190 show guile print-stack
1191 Show a stack trace when an error is encountered in a Guile script.
1193 set auto-load guile-scripts (on|off)
1194 show auto-load guile-scripts
1195 Control auto-loading of Guile script files.
1197 maint ada set ignore-descriptive-types (on|off)
1198 maint ada show ignore-descriptive-types
1199 Control whether the debugger should ignore descriptive types in Ada
1200 programs. The default is not to ignore the descriptive types. See
1201 the user manual for more details on descriptive types and the intended
1202 usage of this option.
1204 set auto-connect-native-target
1206 Control whether GDB is allowed to automatically connect to the
1207 native target for the run, attach, etc. commands when not connected
1208 to any target yet. See also "target native" below.
1210 set record btrace replay-memory-access (read-only|read-write)
1211 show record btrace replay-memory-access
1212 Control what memory accesses are allowed during replay.
1214 maint set target-async (on|off)
1215 maint show target-async
1216 This controls whether GDB targets operate in synchronous or
1217 asynchronous mode. Normally the default is asynchronous, if it is
1218 available; but this can be changed to more easily debug problems
1219 occurring only in synchronous mode.
1221 set mi-async (on|off)
1223 Control whether MI asynchronous mode is preferred. This supersedes
1224 "set target-async" of previous GDB versions.
1226 * "set target-async" is deprecated as a CLI option and is now an alias
1227 for "set mi-async" (only puts MI into async mode).
1229 * Background execution commands (e.g., "c&", "s&", etc.) are now
1230 possible ``out of the box'' if the target supports them. Previously
1231 the user would need to explicitly enable the possibility with the
1232 "set target-async on" command.
1234 * New features in the GDB remote stub, GDBserver
1236 ** New option --debug-format=option1[,option2,...] allows one to add
1237 additional text to each output. At present only timestamps
1238 are supported: --debug-format=timestamps.
1239 Timestamps can also be turned on with the
1240 "monitor set debug-format timestamps" command from GDB.
1242 * The 'record instruction-history' command now starts counting instructions
1243 at one. This also affects the instruction ranges reported by the
1244 'record function-call-history' command when given the /i modifier.
1246 * The command 'record function-call-history' supports a new modifier '/c' to
1247 indent the function names based on their call stack depth.
1248 The fields for the '/i' and '/l' modifier have been reordered.
1249 The source line range is now prefixed with 'at'.
1250 The instruction range is now prefixed with 'inst'.
1251 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1252 "record instruction-history" and "list" commands.
1254 * The ranges given as arguments to the 'record function-call-history' and
1255 'record instruction-history' commands are now inclusive.
1257 * The btrace record target now supports the 'record goto' command.
1258 For locations inside the execution trace, the back trace is computed
1259 based on the information stored in the execution trace.
1261 * The btrace record target supports limited reverse execution and replay.
1262 The target does not record data and therefore does not allow reading
1263 memory or registers.
1265 * The "catch syscall" command now works on s390*-linux* targets.
1267 * The "compare-sections" command is no longer specific to target
1268 remote. It now works with all targets.
1270 * All native targets are now consistently called "native".
1271 Consequently, the "target child", "target GNU", "target djgpp",
1272 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1273 commands have been replaced with "target native". The QNX/NTO port
1274 leaves the "procfs" target in place and adds a "native" target for
1275 consistency with other ports. The impact on users should be minimal
1276 as these commands previously either throwed an error, or were
1277 no-ops. The target's name is visible in the output of the following
1278 commands: "help target", "info target", "info files", "maint print
1281 * The "target native" command now connects to the native target. This
1282 can be used to launch native programs even when "set
1283 auto-connect-native-target" is set to off.
1285 * GDB now supports access to Intel MPX registers on GNU/Linux.
1287 * Support for Intel AVX-512 registers on GNU/Linux.
1288 Support displaying and modifying Intel AVX-512 registers
1289 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1291 * New remote packets
1293 qXfer:btrace:read's annex
1294 The qXfer:btrace:read packet supports a new annex 'delta' to read
1295 branch trace incrementally.
1299 ** Valid Python operations on gdb.Value objects representing
1300 structs/classes invoke the corresponding overloaded operators if
1302 ** New `Xmethods' feature in the Python API. Xmethods are
1303 additional methods or replacements for existing methods of a C++
1304 class. This feature is useful for those cases where a method
1305 defined in C++ source code could be inlined or optimized out by
1306 the compiler, making it unavailable to GDB.
1309 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1311 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1312 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1313 its alias "share", instead.
1315 * The commands "set remotebaud" and "show remotebaud" are no longer
1316 supported. Use "set serial baud" and "show serial baud" (respectively)
1321 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1322 target-async". The latter is left as a deprecated alias of the
1323 former for backward compatibility. If the target supports it,
1324 CLI background execution commands are now always possible by
1325 default, independently of whether the frontend stated a
1326 preference for asynchronous execution with "-gdb-set mi-async".
1327 Previously "-gdb-set target-async off" affected both MI execution
1328 commands and CLI execution commands.
1330 *** Changes in GDB 7.7
1332 * Improved support for process record-replay and reverse debugging on
1333 arm*-linux* targets. Support for thumb32 and syscall instruction
1334 recording has been added.
1336 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1338 * GDB now supports Fission DWP file format version 2.
1339 http://gcc.gnu.org/wiki/DebugFission
1341 * New convenience function "$_isvoid", to check whether an expression
1342 is void. A void expression is an expression where the type of the
1343 result is "void". For example, some convenience variables may be
1344 "void" when evaluated (e.g., "$_exitcode" before the execution of
1345 the program being debugged; or an undefined convenience variable).
1346 Another example, when calling a function whose return type is
1349 * The "maintenance print objfiles" command now takes an optional regexp.
1351 * The "catch syscall" command now works on arm*-linux* targets.
1353 * GDB now consistently shows "<not saved>" when printing values of
1354 registers the debug info indicates have not been saved in the frame
1355 and there's nowhere to retrieve them from
1356 (callee-saved/call-clobbered registers):
1361 (gdb) info registers rax
1364 Before, the former would print "<optimized out>", and the latter
1365 "*value not available*".
1367 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1372 ** Frame filters and frame decorators have been added.
1373 ** Temporary breakpoints are now supported.
1374 ** Line tables representation has been added.
1375 ** New attribute 'parent_type' for gdb.Field objects.
1376 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1377 ** New attribute 'name' for gdb.Type objects.
1381 Nios II ELF nios2*-*-elf
1382 Nios II GNU/Linux nios2*-*-linux
1383 Texas Instruments MSP430 msp430*-*-elf
1385 * Removed native configurations
1387 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1388 been removed. ELF variants of these configurations are kept supported.
1390 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1391 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1392 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1393 i[34567]86-*-openbsd3.[0-3]
1394 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1395 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1396 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1400 Like "catch throw", but catches a re-thrown exception.
1401 maint check-psymtabs
1402 Renamed from old "maint check-symtabs".
1404 Perform consistency checks on symtabs.
1405 maint expand-symtabs
1406 Expand symtabs matching an optional regexp.
1409 Display the details of GDB configure-time options.
1411 maint set|show per-command
1412 maint set|show per-command space
1413 maint set|show per-command time
1414 maint set|show per-command symtab
1415 Enable display of per-command gdb resource usage.
1417 remove-symbol-file FILENAME
1418 remove-symbol-file -a ADDRESS
1419 Remove a symbol file added via add-symbol-file. The file to remove
1420 can be identified by its filename or by an address that lies within
1421 the boundaries of this symbol file in memory.
1424 info exceptions REGEXP
1425 Display the list of Ada exceptions defined in the program being
1426 debugged. If provided, only the exceptions whose names match REGEXP
1431 set debug symfile off|on
1433 Control display of debugging info regarding reading symbol files and
1434 symbol tables within those files
1436 set print raw frame-arguments
1437 show print raw frame-arguments
1438 Set/show whether to print frame arguments in raw mode,
1439 disregarding any defined pretty-printers.
1441 set remote trace-status-packet
1442 show remote trace-status-packet
1443 Set/show the use of remote protocol qTStatus packet.
1447 Control display of debugging messages related to Nios II targets.
1451 Control whether target-assisted range stepping is enabled.
1453 set startup-with-shell
1454 show startup-with-shell
1455 Specifies whether Unix child processes are started via a shell or
1460 Use the target memory cache for accesses to the code segment. This
1461 improves performance of remote debugging (particularly disassembly).
1463 * You can now use a literal value 'unlimited' for options that
1464 interpret 0 or -1 as meaning "unlimited". E.g., "set
1465 trace-buffer-size unlimited" is now an alias for "set
1466 trace-buffer-size -1" and "set height unlimited" is now an alias for
1469 * The "set debug symtab-create" debugging option of GDB has been changed to
1470 accept a verbosity level. 0 means "off", 1 provides basic debugging
1471 output, and values of 2 or greater provides more verbose output.
1473 * New command-line options
1475 Display the details of GDB configure-time options.
1477 * The command 'tsave' can now support new option '-ctf' to save trace
1478 buffer in Common Trace Format.
1480 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1483 * GDB now implements the the C++ 'typeid' operator.
1485 * The new convenience variable $_exception holds the exception being
1486 thrown or caught at an exception-related catchpoint.
1488 * The exception-related catchpoints, like "catch throw", now accept a
1489 regular expression which can be used to filter exceptions by type.
1491 * The new convenience variable $_exitsignal is automatically set to
1492 the terminating signal number when the program being debugged dies
1493 due to an uncaught signal.
1497 ** All MI commands now accept an optional "--language" option.
1498 Support for this feature can be verified by using the "-list-features"
1499 command, which should contain "language-option".
1501 ** The new command -info-gdb-mi-command allows the user to determine
1502 whether a GDB/MI command is supported or not.
1504 ** The "^error" result record returned when trying to execute an undefined
1505 GDB/MI command now provides a variable named "code" whose content is the
1506 "undefined-command" error code. Support for this feature can be verified
1507 by using the "-list-features" command, which should contain
1508 "undefined-command-error-code".
1510 ** The -trace-save MI command can optionally save trace buffer in Common
1513 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1515 ** The command -data-list-register-values now accepts an optional
1516 "--skip-unavailable" option. When used, only the available registers
1519 ** The new command -trace-frame-collected dumps collected variables,
1520 computed expressions, tvars, memory and registers in a traceframe.
1522 ** The commands -stack-list-locals, -stack-list-arguments and
1523 -stack-list-variables now accept an option "--skip-unavailable".
1524 When used, only the available locals or arguments are displayed.
1526 ** The -exec-run command now accepts an optional "--start" option.
1527 When used, the command follows the same semantics as the "start"
1528 command, stopping the program's execution at the start of its
1529 main subprogram. Support for this feature can be verified using
1530 the "-list-features" command, which should contain
1531 "exec-run-start-option".
1533 ** The new commands -catch-assert and -catch-exceptions insert
1534 catchpoints stopping the program when Ada exceptions are raised.
1536 ** The new command -info-ada-exceptions provides the equivalent of
1537 the new "info exceptions" command.
1539 * New system-wide configuration scripts
1540 A GDB installation now provides scripts suitable for use as system-wide
1541 configuration scripts for the following systems:
1545 * GDB now supports target-assigned range stepping with remote targets.
1546 This improves the performance of stepping source lines by reducing
1547 the number of control packets from/to GDB. See "New remote packets"
1550 * GDB now understands the element 'tvar' in the XML traceframe info.
1551 It has the id of the collected trace state variables.
1553 * On S/390 targets that provide the transactional-execution feature,
1554 the program interruption transaction diagnostic block (TDB) is now
1555 represented as a number of additional "registers" in GDB.
1557 * New remote packets
1561 The vCont packet supports a new 'r' action, that tells the remote
1562 stub to step through an address range itself, without GDB
1563 involvemement at each single-step.
1565 qXfer:libraries-svr4:read's annex
1566 The previously unused annex of the qXfer:libraries-svr4:read packet
1567 is now used to support passing an argument list. The remote stub
1568 reports support for this argument list to GDB's qSupported query.
1569 The defined arguments are "start" and "prev", used to reduce work
1570 necessary for library list updating, resulting in significant
1573 * New features in the GDB remote stub, GDBserver
1575 ** GDBserver now supports target-assisted range stepping. Currently
1576 enabled on x86/x86_64 GNU/Linux targets.
1578 ** GDBserver now adds element 'tvar' in the XML in the reply to
1579 'qXfer:traceframe-info:read'. It has the id of the collected
1580 trace state variables.
1582 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1585 * New 'z' formatter for printing and examining memory, this displays the
1586 value as hexadecimal zero padded on the left to the size of the type.
1588 * GDB can now use Windows x64 unwinding data.
1590 * The "set remotebaud" command has been replaced by "set serial baud".
1591 Similarly, "show remotebaud" has been replaced by "show serial baud".
1592 The "set remotebaud" and "show remotebaud" commands are still available
1593 to provide backward compatibility with older versions of GDB.
1595 *** Changes in GDB 7.6
1597 * Target record has been renamed to record-full.
1598 Record/replay is now enabled with the "record full" command.
1599 This also affects settings that are associated with full record/replay
1600 that have been moved from "set/show record" to "set/show record full":
1602 set|show record full insn-number-max
1603 set|show record full stop-at-limit
1604 set|show record full memory-query
1606 * A new record target "record-btrace" has been added. The new target
1607 uses hardware support to record the control-flow of a process. It
1608 does not support replaying the execution, but it implements the
1609 below new commands for investigating the recorded execution log.
1610 This new recording method can be enabled using:
1614 The "record-btrace" target is only available on Intel Atom processors
1615 and requires a Linux kernel 2.6.32 or later.
1617 * Two new commands have been added for record/replay to give information
1618 about the recorded execution without having to replay the execution.
1619 The commands are only supported by "record btrace".
1621 record instruction-history prints the execution history at
1622 instruction granularity
1624 record function-call-history prints the execution history at
1625 function granularity
1627 * New native configurations
1629 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1630 FreeBSD/powerpc powerpc*-*-freebsd
1631 x86_64/Cygwin x86_64-*-cygwin*
1632 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1636 ARM AArch64 aarch64*-*-elf
1637 ARM AArch64 GNU/Linux aarch64*-*-linux
1638 Lynx 178 PowerPC powerpc-*-lynx*178
1639 x86_64/Cygwin x86_64-*-cygwin*
1640 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1642 * If the configured location of system.gdbinit file (as given by the
1643 --with-system-gdbinit option at configure time) is in the
1644 data-directory (as specified by --with-gdb-datadir at configure
1645 time) or in one of its subdirectories, then GDB will look for the
1646 system-wide init file in the directory specified by the
1647 --data-directory command-line option.
1649 * New command line options:
1651 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1652 other initialization files, unlike -nx which disables all of them.
1654 * Removed command line options
1656 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1659 * The 'ptype' and 'whatis' commands now accept an argument to control
1662 * 'info proc' now works on some core files.
1666 ** Vectors can be created with gdb.Type.vector.
1668 ** Python's atexit.register now works in GDB.
1670 ** Types can be pretty-printed via a Python API.
1672 ** Python 3 is now supported (in addition to Python 2.4 or later)
1674 ** New class gdb.Architecture exposes GDB's internal representation
1675 of architecture in the Python API.
1677 ** New method Frame.architecture returns the gdb.Architecture object
1678 corresponding to the frame's architecture.
1680 * New Python-based convenience functions:
1682 ** $_memeq(buf1, buf2, length)
1683 ** $_streq(str1, str2)
1685 ** $_regex(str, regex)
1687 * The 'cd' command now defaults to using '~' (the home directory) if not
1690 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1691 default for GCC since November 2000.
1693 * The command 'forward-search' can now be abbreviated as 'fo'.
1695 * The command 'info tracepoints' can now display 'installed on target'
1696 or 'not installed on target' for each non-pending location of tracepoint.
1698 * New configure options
1700 --enable-libmcheck/--disable-libmcheck
1701 By default, development versions are built with -lmcheck on hosts
1702 that support it, in order to help track memory corruption issues.
1703 Release versions, on the other hand, are built without -lmcheck
1704 by default. The --enable-libmcheck/--disable-libmcheck configure
1705 options allow the user to override that default.
1706 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1707 This configure option allows the user to build GDB with
1708 libbabeltrace using which GDB can read Common Trace Format data.
1710 * New commands (for set/show, see "New options" below)
1713 Catch signals. This is similar to "handle", but allows commands and
1714 conditions to be attached.
1717 List the BFDs known to GDB.
1719 python-interactive [command]
1721 Start a Python interactive prompt, or evaluate the optional command
1722 and print the result of expressions.
1725 "py" is a new alias for "python".
1727 enable type-printer [name]...
1728 disable type-printer [name]...
1729 Enable or disable type printers.
1733 ** For the Renesas Super-H architecture, the "regs" command has been removed
1734 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1739 set print type methods (on|off)
1740 show print type methods
1741 Control whether method declarations are displayed by "ptype".
1742 The default is to show them.
1744 set print type typedefs (on|off)
1745 show print type typedefs
1746 Control whether typedef definitions are displayed by "ptype".
1747 The default is to show them.
1749 set filename-display basename|relative|absolute
1750 show filename-display
1751 Control the way in which filenames is displayed.
1752 The default is "relative", which preserves previous behavior.
1754 set trace-buffer-size
1755 show trace-buffer-size
1756 Request target to change the size of trace buffer.
1758 set remote trace-buffer-size-packet auto|on|off
1759 show remote trace-buffer-size-packet
1760 Control the use of the remote protocol `QTBuffer:size' packet.
1764 Control display of debugging messages related to ARM AArch64.
1767 set debug coff-pe-read
1768 show debug coff-pe-read
1769 Control display of debugging messages related to reading of COFF/PE
1774 Control display of debugging messages related to Mach-O symbols
1777 set debug notification
1778 show debug notification
1779 Control display of debugging info for async remote notification.
1783 ** Command parameter changes are now notified using new async record
1784 "=cmd-param-changed".
1785 ** Trace frame changes caused by command "tfind" are now notified using
1786 new async record "=traceframe-changed".
1787 ** The creation, deletion and modification of trace state variables
1788 are now notified using new async records "=tsv-created",
1789 "=tsv-deleted" and "=tsv-modified".
1790 ** The start and stop of process record are now notified using new
1791 async record "=record-started" and "=record-stopped".
1792 ** Memory changes are now notified using new async record
1794 ** The data-disassemble command response will include a "fullname" field
1795 containing the absolute file name when source has been requested.
1796 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1797 command, to allow pattern filling of memory areas.
1798 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1799 library load/unload events.
1800 ** The response to breakpoint commands and breakpoint async records
1801 includes an "installed" field containing a boolean state about each
1802 non-pending tracepoint location is whether installed on target or not.
1803 ** Output of the "-trace-status" command includes a "trace-file" field
1804 containing the name of the trace file being examined. This field is
1805 optional, and only present when examining a trace file.
1806 ** The "fullname" field is now always present along with the "file" field,
1807 even if the file cannot be found by GDB.
1809 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1810 You must have the LZMA library available when configuring GDB for this
1811 feature to be enabled. For more information, see:
1812 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1814 * New remote packets
1817 Set the size of trace buffer. The remote stub reports support for this
1818 packet to gdb's qSupported query.
1821 Enable Branch Trace Store (BTS)-based branch tracing for the current
1822 thread. The remote stub reports support for this packet to gdb's
1826 Disable branch tracing for the current thread. The remote stub reports
1827 support for this packet to gdb's qSupported query.
1830 Read the traced branches for the current thread. The remote stub
1831 reports support for this packet to gdb's qSupported query.
1833 *** Changes in GDB 7.5
1835 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1836 for more x32 ABI info.
1838 * GDB now supports access to MIPS DSP registers on Linux targets.
1840 * GDB now supports debugging microMIPS binaries.
1842 * The "info os" command on GNU/Linux can now display information on
1843 several new classes of objects managed by the operating system:
1844 "info os procgroups" lists process groups
1845 "info os files" lists file descriptors
1846 "info os sockets" lists internet-domain sockets
1847 "info os shm" lists shared-memory regions
1848 "info os semaphores" lists semaphores
1849 "info os msg" lists message queues
1850 "info os modules" lists loaded kernel modules
1852 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1853 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1854 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1855 options and inspect the probe arguments using the new $_probe_arg family
1856 of convenience variables. You can obtain more information about SystemTap
1857 in <http://sourceware.org/systemtap/>.
1859 * GDB now supports reversible debugging on ARM, it allows you to
1860 debug basic ARM and THUMB instructions, and provides
1861 record/replay support.
1863 * The option "symbol-reloading" has been deleted as it is no longer used.
1867 ** GDB commands implemented in Python can now be put in command class
1870 ** The "maint set python print-stack on|off" is now deleted.
1872 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1873 apply "flag enum"-style pretty-printing to any enum.
1875 ** gdb.lookup_symbol can now work when there is no current frame.
1877 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1878 the source at which the symbol was defined.
1880 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1881 method 'value'. The former indicates whether the symbol needs a
1882 frame in order to compute its value, and the latter computes the
1885 ** A new method 'referenced_value' on gdb.Value objects which can
1886 dereference pointer as well as C++ reference values.
1888 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1889 which return the global and static blocks (as gdb.Block objects),
1890 of the underlying symbol table, respectively.
1892 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1893 object associated with a PC value.
1895 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1896 of the address range occupied by code for the current source line.
1898 * Go language support.
1899 GDB now supports debugging programs written in the Go programming
1902 * GDBserver now supports stdio connections.
1903 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1905 * The binary "gdbtui" can no longer be built or installed.
1906 Use "gdb -tui" instead.
1908 * GDB will now print "flag" enums specially. A flag enum is one where
1909 all the enumerator values have no bits in common when pairwise
1910 "and"ed. When printing a value whose type is a flag enum, GDB will
1911 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1912 (gdb) print (enum E) 3
1915 * The filename part of a linespec will now match trailing components
1916 of a source file name. For example, "break gcc/expr.c:1000" will
1917 now set a breakpoint in build/gcc/expr.c, but not
1918 build/libcpp/expr.c.
1920 * The "info proc" and "generate-core-file" commands will now also
1921 work on remote targets connected to GDBserver on Linux.
1923 * The command "info catch" has been removed. It has been disabled
1924 since December 2007.
1926 * The "catch exception" and "catch assert" commands now accept
1927 a condition at the end of the command, much like the "break"
1928 command does. For instance:
1930 (gdb) catch exception Constraint_Error if Barrier = True
1932 Previously, it was possible to add a condition to such catchpoints,
1933 but it had to be done as a second step, after the catchpoint had been
1934 created, using the "condition" command.
1936 * The "info static-tracepoint-marker" command will now also work on
1937 native Linux targets with in-process agent.
1939 * GDB can now set breakpoints on inlined functions.
1941 * The .gdb_index section has been updated to include symbols for
1942 inlined functions. GDB will ignore older .gdb_index sections by
1943 default, which could cause symbol files to be loaded more slowly
1944 until their .gdb_index sections can be recreated. The new command
1945 "set use-deprecated-index-sections on" will cause GDB to use any older
1946 .gdb_index sections it finds. This will restore performance, but the
1947 ability to set breakpoints on inlined functions will be lost in symbol
1948 files with older .gdb_index sections.
1950 The .gdb_index section has also been updated to record more information
1951 about each symbol. This speeds up the "info variables", "info functions"
1952 and "info types" commands when used with programs having the .gdb_index
1953 section, as well as speeding up debugging with shared libraries using
1954 the .gdb_index section.
1956 * Ada support for GDB/MI Variable Objects has been added.
1958 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1963 ** New command -info-os is the MI equivalent of "info os".
1965 ** Output logs ("set logging" and related) now include MI output.
1969 ** "set use-deprecated-index-sections on|off"
1970 "show use-deprecated-index-sections on|off"
1971 Controls the use of deprecated .gdb_index sections.
1973 ** "catch load" and "catch unload" can be used to stop when a shared
1974 library is loaded or unloaded, respectively.
1976 ** "enable count" can be used to auto-disable a breakpoint after
1979 ** "info vtbl" can be used to show the virtual method tables for
1980 C++ and Java objects.
1982 ** "explore" and its sub commands "explore value" and "explore type"
1983 can be used to recursively explore values and types of
1984 expressions. These commands are available only if GDB is
1985 configured with '--with-python'.
1987 ** "info auto-load" shows status of all kinds of auto-loaded files,
1988 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1989 sequences of commands files, "info auto-load python-scripts"
1990 shows status of auto-loading Python script files,
1991 "info auto-load local-gdbinit" shows status of loading init file
1992 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1993 status of inferior specific thread debugging shared library loading.
1995 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1996 and "show auto-load-scripts" commands have been deprecated, use their
1997 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1998 and "show auto-load python-scripts" counterparts instead.
2000 ** "dprintf location,format,args..." creates a dynamic printf, which
2001 is basically a breakpoint that does a printf and immediately
2002 resumes your program's execution, so it is like a printf that you
2003 can insert dynamically at runtime instead of at compiletime.
2005 ** "set print symbol"
2007 Controls whether GDB attempts to display the symbol, if any,
2008 corresponding to addresses it prints. This defaults to "on", but
2009 you can set it to "off" to restore GDB's previous behavior.
2011 * Deprecated commands
2013 ** For the Renesas Super-H architecture, the "regs" command has been
2014 deprecated, and "info all-registers" should be used instead.
2018 Renesas RL78 rl78-*-elf
2019 HP OpenVMS ia64 ia64-hp-openvms*
2021 * GDBserver supports evaluation of breakpoint conditions. When
2022 support is advertised by GDBserver, GDB may be told to send the
2023 breakpoint conditions in bytecode form to GDBserver. GDBserver
2024 will only report the breakpoint trigger to GDB when its condition
2029 set mips compression
2030 show mips compression
2031 Select the compressed ISA encoding used in functions that have no symbol
2032 information available. The encoding can be set to either of:
2035 and is updated automatically from ELF file flags if available.
2037 set breakpoint condition-evaluation
2038 show breakpoint condition-evaluation
2039 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2040 GDBserver ("target"). Default option "auto" chooses the most efficient
2042 This option can improve debugger efficiency depending on the speed of the
2046 Disable auto-loading globally.
2049 Show auto-loading setting of all kinds of auto-loaded files.
2051 set auto-load gdb-scripts on|off
2052 show auto-load gdb-scripts
2053 Control auto-loading of GDB canned sequences of commands files.
2055 set auto-load python-scripts on|off
2056 show auto-load python-scripts
2057 Control auto-loading of Python script files.
2059 set auto-load local-gdbinit on|off
2060 show auto-load local-gdbinit
2061 Control loading of init file (.gdbinit) from current directory.
2063 set auto-load libthread-db on|off
2064 show auto-load libthread-db
2065 Control auto-loading of inferior specific thread debugging shared library.
2067 set auto-load scripts-directory <dir1>[:<dir2>...]
2068 show auto-load scripts-directory
2069 Set a list of directories from which to load auto-loaded scripts.
2070 Automatically loaded Python scripts and GDB scripts are located in one
2071 of the directories listed by this option.
2072 The delimiter (':' above) may differ according to the host platform.
2074 set auto-load safe-path <dir1>[:<dir2>...]
2075 show auto-load safe-path
2076 Set a list of directories from which it is safe to auto-load files.
2077 The delimiter (':' above) may differ according to the host platform.
2079 set debug auto-load on|off
2080 show debug auto-load
2081 Control display of debugging info for auto-loading the files above.
2083 set dprintf-style gdb|call|agent
2085 Control the way in which a dynamic printf is performed; "gdb"
2086 requests a GDB printf command, while "call" causes dprintf to call a
2087 function in the inferior. "agent" requests that the target agent
2088 (such as GDBserver) do the printing.
2090 set dprintf-function <expr>
2091 show dprintf-function
2092 set dprintf-channel <expr>
2093 show dprintf-channel
2094 Set the function and optional first argument to the call when using
2095 the "call" style of dynamic printf.
2097 set disconnected-dprintf on|off
2098 show disconnected-dprintf
2099 Control whether agent-style dynamic printfs continue to be in effect
2100 after GDB disconnects.
2102 * New configure options
2104 --with-auto-load-dir
2105 Configure default value for the 'set auto-load scripts-directory'
2106 setting above. It defaults to '$debugdir:$datadir/auto-load',
2107 $debugdir representing global debugging info directories (available
2108 via 'show debug-file-directory') and $datadir representing GDB's data
2109 directory (available via 'show data-directory').
2111 --with-auto-load-safe-path
2112 Configure default value for the 'set auto-load safe-path' setting
2113 above. It defaults to the --with-auto-load-dir setting.
2115 --without-auto-load-safe-path
2116 Set 'set auto-load safe-path' to '/', effectively disabling this
2119 * New remote packets
2121 z0/z1 conditional breakpoints extension
2123 The z0/z1 breakpoint insertion packets have been extended to carry
2124 a list of conditional expressions over to the remote stub depending on the
2125 condition evaluation mode. The use of this extension can be controlled
2126 via the "set remote conditional-breakpoints-packet" command.
2130 Specify the signals which the remote stub may pass to the debugged
2131 program without GDB involvement.
2133 * New command line options
2135 --init-command=FILE, -ix Like --command, -x but execute it
2136 before loading inferior.
2137 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2138 execute it before loading inferior.
2140 *** Changes in GDB 7.4
2142 * GDB now handles ambiguous linespecs more consistently; the existing
2143 FILE:LINE support has been expanded to other types of linespecs. A
2144 breakpoint will now be set on all matching locations in all
2145 inferiors, and locations will be added or removed according to
2148 * GDB now allows you to skip uninteresting functions and files when
2149 stepping with the "skip function" and "skip file" commands.
2151 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2152 and "show remote hardware-watchpoint-length-limit". These allows to
2153 set or show the maximum length limit (in bytes) of a remote
2154 target hardware watchpoint.
2156 This allows e.g. to use "unlimited" hardware watchpoints with the
2157 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2158 watchpoints are slower than real hardware watchpoints but are
2159 significantly faster than gdb software watchpoints.
2163 ** The register_pretty_printer function in module gdb.printing now takes
2164 an optional `replace' argument. If True, the new printer replaces any
2167 ** The "maint set python print-stack on|off" command has been
2168 deprecated and will be deleted in GDB 7.5.
2169 A new command: "set python print-stack none|full|message" has
2170 replaced it. Additionally, the default for "print-stack" is
2171 now "message", which just prints the error message without
2174 ** A prompt substitution hook (prompt_hook) is now available to the
2177 ** A new Python module, gdb.prompt has been added to the GDB Python
2178 modules library. This module provides functionality for
2179 escape sequences in prompts (used by set/show
2180 extended-prompt). These escape sequences are replaced by their
2181 corresponding value.
2183 ** Python commands and convenience-functions located in
2184 'data-directory'/python/gdb/command and
2185 'data-directory'/python/gdb/function are now automatically loaded
2188 ** Blocks now provide four new attributes. global_block and
2189 static_block will return the global and static blocks
2190 respectively. is_static and is_global are boolean attributes
2191 that indicate if the block is one of those two types.
2193 ** Symbols now provide the "type" attribute, the type of the symbol.
2195 ** The "gdb.breakpoint" function has been deprecated in favor of
2198 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2199 of a function. This class is based on the "finish" command
2200 available in the CLI.
2202 ** Type objects for struct and union types now allow access to
2203 the fields using standard Python dictionary (mapping) methods.
2204 For example, "some_type['myfield']" now works, as does
2205 "some_type.items()".
2207 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2210 ** A new function, "deep_items" has been added to the gdb.types
2211 module in the GDB Python modules library. This function returns
2212 an iterator over the fields of a struct or union type. Unlike
2213 the standard Python "iteritems" method, it will recursively traverse
2214 any anonymous fields.
2218 ** "*stopped" events can report several new "reason"s, such as
2221 ** Breakpoint changes are now notified using new async records, like
2222 "=breakpoint-modified".
2224 ** New command -ada-task-info.
2226 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2227 $sdir specifies the default system locations of shared libraries.
2228 $pdir specifies the directory where the libpthread used by the application
2231 GDB no longer looks in $sdir and $pdir after it has searched the directories
2232 mentioned in libthread-db-search-path. If you want to search those
2233 directories, they must be specified in libthread-db-search-path.
2234 The default value of libthread-db-search-path on GNU/Linux and Solaris
2235 systems is now "$sdir:$pdir".
2237 $pdir is not supported by gdbserver, it is currently ignored.
2238 $sdir is supported by gdbserver.
2240 * New configure option --with-iconv-bin.
2241 When using the internationalization support like the one in the GNU C
2242 library, GDB will invoke the "iconv" program to get a list of supported
2243 character sets. If this program lives in a non-standard location, one can
2244 use this option to specify where to find it.
2246 * When natively debugging programs on PowerPC BookE processors running
2247 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2248 watchpoints, which specify a mask in addition to an address to watch.
2249 The mask specifies that some bits of an address (the bits which are
2250 reset in the mask) should be ignored when matching the address accessed
2251 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2252 section in the user manual for more details.
2254 * The new option --once causes GDBserver to stop listening for connections once
2255 the first connection is made. The listening port used by GDBserver will
2256 become available after that.
2258 * New commands "info macros" and "alias" have been added.
2260 * New function parameters suffix @entry specifies value of function parameter
2261 at the time the function got called. Entry values are available only since
2267 "!" is now an alias of the "shell" command.
2268 Note that no space is needed between "!" and SHELL COMMAND.
2272 watch EXPRESSION mask MASK_VALUE
2273 The watch command now supports the mask argument which allows creation
2274 of masked watchpoints, if the current architecture supports this feature.
2276 info auto-load-scripts [REGEXP]
2277 This command was formerly named "maintenance print section-scripts".
2278 It is now generally useful and is no longer a maintenance-only command.
2280 info macro [-all] [--] MACRO
2281 The info macro command has new options `-all' and `--'. The first for
2282 printing all definitions of a macro. The second for explicitly specifying
2283 the end of arguments and the beginning of the macro name in case the macro
2284 name starts with a hyphen.
2286 collect[/s] EXPRESSIONS
2287 The tracepoint collect command now takes an optional modifier "/s"
2288 that directs it to dereference pointer-to-character types and
2289 collect the bytes of memory up to a zero byte. The behavior is
2290 similar to what you see when you use the regular print command on a
2291 string. An optional integer following the "/s" sets a bound on the
2292 number of bytes that will be collected.
2295 The trace start command now interprets any supplied arguments as a
2296 note to be recorded with the trace run, with an effect similar to
2297 setting the variable trace-notes.
2300 The trace stop command now interprets any arguments as a note to be
2301 mentioned along with the tstatus report that the trace was stopped
2302 with a command. The effect is similar to setting the variable
2305 * Tracepoints can now be enabled and disabled at any time after a trace
2306 experiment has been started using the standard "enable" and "disable"
2307 commands. It is now possible to start a trace experiment with no enabled
2308 tracepoints; GDB will display a warning, but will allow the experiment to
2309 begin, assuming that tracepoints will be enabled as needed while the trace
2312 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2313 locations with 4-byte instructions, when they were previously
2314 limited to locations with instructions of 5 bytes or longer.
2318 set debug dwarf2-read
2319 show debug dwarf2-read
2320 Turns on or off display of debugging messages related to reading
2321 DWARF debug info. The default is off.
2323 set debug symtab-create
2324 show debug symtab-create
2325 Turns on or off display of debugging messages related to symbol table
2326 creation. The default is off.
2329 show extended-prompt
2330 Set the GDB prompt, and allow escape sequences to be inserted to
2331 display miscellaneous information (see 'help set extended-prompt'
2332 for the list of sequences). This prompt (and any information
2333 accessed through the escape sequences) is updated every time the
2334 prompt is displayed.
2336 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2337 show print entry-values
2338 Set printing of frame argument values at function entry. In some cases
2339 GDB can determine the value of function argument which was passed by the
2340 function caller, even if the value was modified inside the called function.
2342 set debug entry-values
2343 show debug entry-values
2344 Control display of debugging info for determining frame argument values at
2345 function entry and virtual tail call frames.
2347 set basenames-may-differ
2348 show basenames-may-differ
2349 Set whether a source file may have multiple base names.
2350 (A "base name" is the name of a file with the directory part removed.
2351 Example: The base name of "/home/user/hello.c" is "hello.c".)
2352 If set, GDB will canonicalize file names (e.g., expand symlinks)
2353 before comparing them. Canonicalization is an expensive operation,
2354 but it allows the same file be known by more than one base name.
2355 If not set (the default), all source files are assumed to have just
2356 one base name, and gdb will do file name comparisons more efficiently.
2362 Set a user name and notes for the current and any future trace runs.
2363 This is useful for long-running and/or disconnected traces, to
2364 inform others (or yourself) as to who is running the trace, supply
2365 contact information, or otherwise explain what is going on.
2367 set trace-stop-notes
2368 show trace-stop-notes
2369 Set a note attached to the trace run, that is displayed when the
2370 trace has been stopped by a tstop command. This is useful for
2371 instance as an explanation, if you are stopping a trace run that was
2372 started by someone else.
2374 * New remote packets
2378 Dynamically enable a tracepoint in a started trace experiment.
2382 Dynamically disable a tracepoint in a started trace experiment.
2386 Set the user and notes of the trace run.
2390 Query the current status of a tracepoint.
2394 Query the minimum length of instruction at which a fast tracepoint may
2397 * Dcache size (number of lines) and line-size are now runtime-configurable
2398 via "set dcache line" and "set dcache line-size" commands.
2402 Texas Instruments TMS320C6x tic6x-*-*
2406 Renesas RL78 rl78-*-elf
2408 *** Changes in GDB 7.3.1
2410 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2412 *** Changes in GDB 7.3
2414 * GDB has a new command: "thread find [REGEXP]".
2415 It finds the thread id whose name, target id, or thread extra info
2416 matches the given regular expression.
2418 * The "catch syscall" command now works on mips*-linux* targets.
2420 * The -data-disassemble MI command now supports modes 2 and 3 for
2421 dumping the instruction opcodes.
2423 * New command line options
2425 -data-directory DIR Specify DIR as the "data-directory".
2426 This is mostly for testing purposes.
2428 * The "maint set python auto-load on|off" command has been renamed to
2429 "set auto-load-scripts on|off".
2431 * GDB has a new command: "set directories".
2432 It is like the "dir" command except that it replaces the
2433 source path list instead of augmenting it.
2435 * GDB now understands thread names.
2437 On GNU/Linux, "info threads" will display the thread name as set by
2438 prctl or pthread_setname_np.
2440 There is also a new command, "thread name", which can be used to
2441 assign a name internally for GDB to display.
2444 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2445 has been integrated into GDB.
2449 ** The function gdb.Write now accepts an optional keyword 'stream'.
2450 This keyword, when provided, will direct the output to either
2451 stdout, stderr, or GDB's logging output.
2453 ** Parameters can now be be sub-classed in Python, and in particular
2454 you may implement the get_set_doc and get_show_doc functions.
2455 This improves how Parameter set/show documentation is processed
2456 and allows for more dynamic content.
2458 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2459 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2460 have an is_valid method.
2462 ** Breakpoints can now be sub-classed in Python, and in particular
2463 you may implement a 'stop' function that is executed each time
2464 the inferior reaches that breakpoint.
2466 ** New function gdb.lookup_global_symbol looks up a global symbol.
2468 ** GDB values in Python are now callable if the value represents a
2469 function. For example, if 'some_value' represents a function that
2470 takes two integer parameters and returns a value, you can call
2471 that function like so:
2473 result = some_value (10,20)
2475 ** Module gdb.types has been added.
2476 It contains a collection of utilities for working with gdb.Types objects:
2477 get_basic_type, has_field, make_enum_dict.
2479 ** Module gdb.printing has been added.
2480 It contains utilities for writing and registering pretty-printers.
2481 New classes: PrettyPrinter, SubPrettyPrinter,
2482 RegexpCollectionPrettyPrinter.
2483 New function: register_pretty_printer.
2485 ** New commands "info pretty-printers", "enable pretty-printer" and
2486 "disable pretty-printer" have been added.
2488 ** gdb.parameter("directories") is now available.
2490 ** New function gdb.newest_frame returns the newest frame in the
2493 ** The gdb.InferiorThread class has a new "name" attribute. This
2494 holds the thread's name.
2496 ** Python Support for Inferior events.
2497 Python scripts can add observers to be notified of events
2498 occurring in the process being debugged.
2499 The following events are currently supported:
2500 - gdb.events.cont Continue event.
2501 - gdb.events.exited Inferior exited event.
2502 - gdb.events.stop Signal received, and Breakpoint hit events.
2506 ** GDB now puts template parameters in scope when debugging in an
2507 instantiation. For example, if you have:
2509 template<int X> int func (void) { return X; }
2511 then if you step into func<5>, "print X" will show "5". This
2512 feature requires proper debuginfo support from the compiler; it
2513 was added to GCC 4.5.
2515 ** The motion commands "next", "finish", "until", and "advance" now
2516 work better when exceptions are thrown. In particular, GDB will
2517 no longer lose control of the inferior; instead, the GDB will
2518 stop the inferior at the point at which the exception is caught.
2519 This functionality requires a change in the exception handling
2520 code that was introduced in GCC 4.5.
2522 * GDB now follows GCC's rules on accessing volatile objects when
2523 reading or writing target state during expression evaluation.
2524 One notable difference to prior behavior is that "print x = 0"
2525 no longer generates a read of x; the value of the assignment is
2526 now always taken directly from the value being assigned.
2528 * GDB now has some support for using labels in the program's source in
2529 linespecs. For instance, you can use "advance label" to continue
2530 execution to a label.
2532 * GDB now has support for reading and writing a new .gdb_index
2533 section. This section holds a fast index of DWARF debugging
2534 information and can be used to greatly speed up GDB startup and
2535 operation. See the documentation for `save gdb-index' for details.
2537 * The "watch" command now accepts an optional "-location" argument.
2538 When used, this causes GDB to watch the memory referred to by the
2539 expression. Such a watchpoint is never deleted due to it going out
2542 * GDB now supports thread debugging of core dumps on GNU/Linux.
2544 GDB now activates thread debugging using the libthread_db library
2545 when debugging GNU/Linux core dumps, similarly to when debugging
2546 live processes. As a result, when debugging a core dump file, GDB
2547 is now able to display pthread_t ids of threads. For example, "info
2548 threads" shows the same output as when debugging the process when it
2549 was live. In earlier releases, you'd see something like this:
2552 * 1 LWP 6780 main () at main.c:10
2554 While now you see this:
2557 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2559 It is also now possible to inspect TLS variables when debugging core
2562 When debugging a core dump generated on a machine other than the one
2563 used to run GDB, you may need to point GDB at the correct
2564 libthread_db library with the "set libthread-db-search-path"
2565 command. See the user manual for more details on this command.
2567 * When natively debugging programs on PowerPC BookE processors running
2568 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2569 which stop execution of the inferior whenever it executes an instruction
2570 at any address within the specified range. See the "PowerPC Embedded"
2571 section in the user manual for more details.
2573 * New features in the GDB remote stub, GDBserver
2575 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2576 and i686 LynxOS (version 5.x).
2578 ** GDBserver is now supported on Blackfin Linux.
2580 * New native configurations
2582 ia64 HP-UX ia64-*-hpux*
2586 Analog Devices, Inc. Blackfin Processor bfin-*
2588 * Ada task switching is now supported on sparc-elf targets when
2589 debugging a program using the Ravenscar Profile. For more information,
2590 see the "Tasking Support when using the Ravenscar Profile" section
2591 in the GDB user manual.
2593 * Guile support was removed.
2595 * New features in the GNU simulator
2597 ** The --map-info flag lists all known core mappings.
2599 ** CFI flashes may be simulated via the "cfi" device.
2601 *** Changes in GDB 7.2
2603 * Shared library support for remote targets by default
2605 When GDB is configured for a generic, non-OS specific target, like
2606 for example, --target=arm-eabi or one of the many *-*-elf targets,
2607 GDB now queries remote stubs for loaded shared libraries using the
2608 `qXfer:libraries:read' packet. Previously, shared library support
2609 was always disabled for such configurations.
2613 ** Argument Dependent Lookup (ADL)
2615 In C++ ADL lookup directs function search to the namespaces of its
2616 arguments even if the namespace has not been imported.
2626 Here the compiler will search for `foo' in the namespace of 'b'
2627 and find A::foo. GDB now supports this. This construct is commonly
2628 used in the Standard Template Library for operators.
2630 ** Improved User Defined Operator Support
2632 In addition to member operators, GDB now supports lookup of operators
2633 defined in a namespace and imported with a `using' directive, operators
2634 defined in the global scope, operators imported implicitly from an
2635 anonymous namespace, and the ADL operators mentioned in the previous
2637 GDB now also supports proper overload resolution for all the previously
2638 mentioned flavors of operators.
2640 ** static const class members
2642 Printing of static const class members that are initialized in the
2643 class definition has been fixed.
2645 * Windows Thread Information Block access.
2647 On Windows targets, GDB now supports displaying the Windows Thread
2648 Information Block (TIB) structure. This structure is visible either
2649 by using the new command `info w32 thread-information-block' or, by
2650 dereferencing the new convenience variable named `$_tlb', a
2651 thread-specific pointer to the TIB. This feature is also supported
2652 when remote debugging using GDBserver.
2654 * Static tracepoints
2656 Static tracepoints are calls in the user program into a tracing
2657 library. One such library is a port of the LTTng kernel tracer to
2658 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2659 When debugging with GDBserver, GDB now supports combining the GDB
2660 tracepoint machinery with such libraries. For example: the user can
2661 use GDB to probe a static tracepoint marker (a call from the user
2662 program into the tracing library) with the new "strace" command (see
2663 "New commands" below). This creates a "static tracepoint" in the
2664 breakpoint list, that can be manipulated with the same feature set
2665 as fast and regular tracepoints. E.g., collect registers, local and
2666 global variables, collect trace state variables, and define
2667 tracepoint conditions. In addition, the user can collect extra
2668 static tracepoint marker specific data, by collecting the new
2669 $_sdata internal variable. When analyzing the trace buffer, you can
2670 inspect $_sdata like any other variable available to GDB. For more
2671 information, see the "Tracepoints" chapter in GDB user manual. New
2672 remote packets have been defined to support static tracepoints, see
2673 the "New remote packets" section below.
2675 * Better reconstruction of tracepoints after disconnected tracing
2677 GDB will attempt to download the original source form of tracepoint
2678 definitions when starting a trace run, and then will upload these
2679 upon reconnection to the target, resulting in a more accurate
2680 reconstruction of the tracepoints that are in use on the target.
2684 You can now exercise direct control over the ways that GDB can
2685 affect your program. For instance, you can disallow the setting of
2686 breakpoints, so that the program can run continuously (assuming
2687 non-stop mode). In addition, the "observer" variable is available
2688 to switch all of the different controls; in observer mode, GDB
2689 cannot affect the target's behavior at all, which is useful for
2690 tasks like diagnosing live systems in the field.
2692 * The new convenience variable $_thread holds the number of the
2695 * New remote packets
2699 Return the address of the Windows Thread Information Block of a given thread.
2703 In response to several of the tracepoint packets, the target may now
2704 also respond with a number of intermediate `qRelocInsn' request
2705 packets before the final result packet, to have GDB handle
2706 relocating an instruction to execute at a different address. This
2707 is particularly useful for stubs that support fast tracepoints. GDB
2708 reports support for this feature in the qSupported packet.
2712 List static tracepoint markers in the target program.
2716 List static tracepoint markers at a given address in the target
2719 qXfer:statictrace:read
2721 Read the static trace data collected (by a `collect $_sdata'
2722 tracepoint action). The remote stub reports support for this packet
2723 to gdb's qSupported query.
2727 Send the current settings of GDB's permission flags.
2731 Send part of the source (textual) form of a tracepoint definition,
2732 which includes location, conditional, and action list.
2734 * The source command now accepts a -s option to force searching for the
2735 script in the source search path even if the script name specifies
2738 * New features in the GDB remote stub, GDBserver
2740 - GDBserver now support tracepoints (including fast tracepoints, and
2741 static tracepoints). The feature is currently supported by the
2742 i386-linux and amd64-linux builds. See the "Tracepoints support
2743 in gdbserver" section in the manual for more information.
2745 GDBserver JIT compiles the tracepoint's conditional agent
2746 expression bytecode into native code whenever possible for low
2747 overhead dynamic tracepoints conditionals. For such tracepoints,
2748 an expression that examines program state is evaluated when the
2749 tracepoint is reached, in order to determine whether to capture
2750 trace data. If the condition is simple and false, processing the
2751 tracepoint finishes very quickly and no data is gathered.
2753 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2754 for static tracepoints support.
2756 - GDBserver now supports x86_64 Windows 64-bit debugging.
2758 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2759 it understands register description.
2761 * The --batch flag now disables pagination and queries.
2763 * X86 general purpose registers
2765 GDB now supports reading/writing byte, word and double-word x86
2766 general purpose registers directly. This means you can use, say,
2767 $ah or $ax to refer, respectively, to the byte register AH and
2768 16-bit word register AX that are actually portions of the 32-bit
2769 register EAX or 64-bit register RAX.
2771 * The `commands' command now accepts a range of breakpoints to modify.
2772 A plain `commands' following a command that creates multiple
2773 breakpoints affects all the breakpoints set by that command. This
2774 applies to breakpoints set by `rbreak', and also applies when a
2775 single `break' command creates multiple breakpoints (e.g.,
2776 breakpoints on overloaded c++ functions).
2778 * The `rbreak' command now accepts a filename specification as part of
2779 its argument, limiting the functions selected by the regex to those
2780 in the specified file.
2782 * Support for remote debugging Windows and SymbianOS shared libraries
2783 from Unix hosts has been improved. Non Windows GDB builds now can
2784 understand target reported file names that follow MS-DOS based file
2785 system semantics, such as file names that include drive letters and
2786 use the backslash character as directory separator. This makes it
2787 possible to transparently use the "set sysroot" and "set
2788 solib-search-path" on Unix hosts to point as host copies of the
2789 target's shared libraries. See the new command "set
2790 target-file-system-kind" described below, and the "Commands to
2791 specify files" section in the user manual for more information.
2795 eval template, expressions...
2796 Convert the values of one or more expressions under the control
2797 of the string template to a command line, and call it.
2799 set target-file-system-kind unix|dos-based|auto
2800 show target-file-system-kind
2801 Set or show the assumed file system kind for target reported file
2804 save breakpoints <filename>
2805 Save all current breakpoint definitions to a file suitable for use
2806 in a later debugging session. To read the saved breakpoint
2807 definitions, use the `source' command.
2809 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2812 info static-tracepoint-markers
2813 Display information about static tracepoint markers in the target.
2815 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2816 Define a static tracepoint by probing a marker at the given
2817 function, line, address, or marker ID.
2821 Enable and disable observer mode.
2823 set may-write-registers on|off
2824 set may-write-memory on|off
2825 set may-insert-breakpoints on|off
2826 set may-insert-tracepoints on|off
2827 set may-insert-fast-tracepoints on|off
2828 set may-interrupt on|off
2829 Set individual permissions for GDB effects on the target. Note that
2830 some of these settings can have undesirable or surprising
2831 consequences, particularly when changed in the middle of a session.
2832 For instance, disabling the writing of memory can prevent
2833 breakpoints from being inserted, cause single-stepping to fail, or
2834 even crash your program, if you disable after breakpoints have been
2835 inserted. However, GDB should not crash.
2837 set record memory-query on|off
2838 show record memory-query
2839 Control whether to stop the inferior if memory changes caused
2840 by an instruction cannot be recorded.
2845 The disassemble command now supports "start,+length" form of two arguments.
2849 ** GDB now provides a new directory location, called the python directory,
2850 where Python scripts written for GDB can be installed. The location
2851 of that directory is <data-directory>/python, where <data-directory>
2852 is the GDB data directory. For more details, see section `Scripting
2853 GDB using Python' in the manual.
2855 ** The GDB Python API now has access to breakpoints, symbols, symbol
2856 tables, program spaces, inferiors, threads and frame's code blocks.
2857 Additionally, GDB Parameters can now be created from the API, and
2858 manipulated via set/show in the CLI.
2860 ** New functions gdb.target_charset, gdb.target_wide_charset,
2861 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2863 ** New exception gdb.GdbError.
2865 ** Pretty-printers are now also looked up in the current program space.
2867 ** Pretty-printers can now be individually enabled and disabled.
2869 ** GDB now looks for names of Python scripts to auto-load in a
2870 special section named `.debug_gdb_scripts', in addition to looking
2871 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2873 * Tracepoint actions were unified with breakpoint commands. In particular,
2874 there are no longer differences in "info break" output for breakpoints and
2875 tracepoints and the "commands" command can be used for both tracepoints and
2876 regular breakpoints.
2880 ARM Symbian arm*-*-symbianelf*
2882 * D language support.
2883 GDB now supports debugging programs written in the D programming
2886 * GDB now supports the extended ptrace interface for PowerPC which is
2887 available since Linux kernel version 2.6.34. This automatically enables
2888 any hardware breakpoints and additional hardware watchpoints available in
2889 the processor. The old ptrace interface exposes just one hardware
2890 watchpoint and no hardware breakpoints.
2892 * GDB is now able to use the Data Value Compare (DVC) register available on
2893 embedded PowerPC processors to implement in hardware simple watchpoint
2894 conditions of the form:
2896 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2898 This works in native GDB running on Linux kernels with the extended ptrace
2899 interface mentioned above.
2901 *** Changes in GDB 7.1
2905 ** Namespace Support
2907 GDB now supports importing of namespaces in C++. This enables the
2908 user to inspect variables from imported namespaces. Support for
2909 namepace aliasing has also been added. So, if a namespace is
2910 aliased in the current scope (e.g. namepace C=A; ) the user can
2911 print variables using the alias (e.g. (gdb) print C::x).
2915 All known bugs relating to the printing of virtual base class were
2916 fixed. It is now possible to call overloaded static methods using a
2921 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2922 and reinterpret_cast<> are now handled by the C++ expression parser.
2926 Xilinx MicroBlaze microblaze-*-*
2931 Xilinx MicroBlaze microblaze
2934 * Multi-program debugging.
2936 GDB now has support for multi-program (a.k.a. multi-executable or
2937 multi-exec) debugging. This allows for debugging multiple inferiors
2938 simultaneously each running a different program under the same GDB
2939 session. See "Debugging Multiple Inferiors and Programs" in the
2940 manual for more information. This implied some user visible changes
2941 in the multi-inferior support. For example, "info inferiors" now
2942 lists inferiors that are not running yet or that have exited
2943 already. See also "New commands" and "New options" below.
2945 * New tracing features
2947 GDB's tracepoint facility now includes several new features:
2949 ** Trace state variables
2951 GDB tracepoints now include support for trace state variables, which
2952 are variables managed by the target agent during a tracing
2953 experiment. They are useful for tracepoints that trigger each
2954 other, so for instance one tracepoint can count hits in a variable,
2955 and then a second tracepoint has a condition that is true when the
2956 count reaches a particular value. Trace state variables share the
2957 $-syntax of GDB convenience variables, and can appear in both
2958 tracepoint actions and condition expressions. Use the "tvariable"
2959 command to create, and "info tvariables" to view; see "Trace State
2960 Variables" in the manual for more detail.
2964 GDB now includes an option for defining fast tracepoints, which
2965 targets may implement more efficiently, such as by installing a jump
2966 into the target agent rather than a trap instruction. The resulting
2967 speedup can be by two orders of magnitude or more, although the
2968 tradeoff is that some program locations on some target architectures
2969 might not allow fast tracepoint installation, for instance if the
2970 instruction to be replaced is shorter than the jump. To request a
2971 fast tracepoint, use the "ftrace" command, with syntax identical to
2972 the regular trace command.
2974 ** Disconnected tracing
2976 It is now possible to detach GDB from the target while it is running
2977 a trace experiment, then reconnect later to see how the experiment
2978 is going. In addition, a new variable disconnected-tracing lets you
2979 tell the target agent whether to continue running a trace if the
2980 connection is lost unexpectedly.
2984 GDB now has the ability to save the trace buffer into a file, and
2985 then use that file as a target, similarly to you can do with
2986 corefiles. You can select trace frames, print data that was
2987 collected in them, and use tstatus to display the state of the
2988 tracing run at the moment that it was saved. To create a trace
2989 file, use "tsave <filename>", and to use it, do "target tfile
2992 ** Circular trace buffer
2994 You can ask the target agent to handle the trace buffer as a
2995 circular buffer, discarding the oldest trace frames to make room for
2996 newer ones, by setting circular-trace-buffer to on. This feature may
2997 not be available for all target agents.
3002 The disassemble command, when invoked with two arguments, now requires
3003 the arguments to be comma-separated.
3006 The info variables command now displays variable definitions. Files
3007 which only declare a variable are not shown.
3010 The source command is now capable of sourcing Python scripts.
3011 This feature is dependent on the debugger being build with Python
3014 Related to this enhancement is also the introduction of a new command
3015 "set script-extension" (see below).
3017 * New commands (for set/show, see "New options" below)
3019 record save [<FILENAME>]
3020 Save a file (in core file format) containing the process record
3021 execution log for replay debugging at a later time.
3023 record restore <FILENAME>
3024 Restore the process record execution log that was saved at an
3025 earlier time, for replay debugging.
3027 add-inferior [-copies <N>] [-exec <FILENAME>]
3030 clone-inferior [-copies <N>] [ID]
3031 Make a new inferior ready to execute the same program another
3032 inferior has loaded.
3037 maint info program-spaces
3038 List the program spaces loaded into GDB.
3040 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3041 show remote interrupt-sequence
3042 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3043 as the sequence to the remote target in order to interrupt the execution.
3044 Ctrl-C is a default. Some system prefers BREAK which is high level of
3045 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3046 Magic SysRq g. It is BREAK signal and character 'g'.
3048 set remote interrupt-on-connect [on | off]
3049 show remote interrupt-on-connect
3050 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3051 remote target when gdb connects to it. This is needed when you debug
3054 set remotebreak [on | off]
3056 Deprecated. Use "set/show remote interrupt-sequence" instead.
3058 tvariable $NAME [ = EXP ]
3059 Create or modify a trace state variable.
3062 List trace state variables and their values.
3064 delete tvariable $NAME ...
3065 Delete one or more trace state variables.
3068 Evaluate the given expressions without collecting anything into the
3069 trace buffer. (Valid in tracepoint actions only.)
3071 ftrace FN / FILE:LINE / *ADDR
3072 Define a fast tracepoint at the given function, line, or address.
3074 * New expression syntax
3076 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3077 GDB now parses 0b101010 identically with 42.
3081 set follow-exec-mode new|same
3082 show follow-exec-mode
3083 Control whether GDB reuses the same inferior across an exec call or
3084 creates a new one. This is useful to be able to restart the old
3085 executable after the inferior having done an exec call.
3087 set default-collect EXPR, ...
3088 show default-collect
3089 Define a list of expressions to be collected at each tracepoint.
3090 This is a useful way to ensure essential items are not overlooked,
3091 such as registers or a critical global variable.
3093 set disconnected-tracing
3094 show disconnected-tracing
3095 If set to 1, the target is instructed to continue tracing if it
3096 loses its connection to GDB. If 0, the target is to stop tracing
3099 set circular-trace-buffer
3100 show circular-trace-buffer
3101 If set to on, the target is instructed to use a circular trace buffer
3102 and discard the oldest trace frames instead of stopping the trace due
3103 to a full trace buffer. If set to off, the trace stops when the buffer
3104 fills up. Some targets may not support this.
3106 set script-extension off|soft|strict
3107 show script-extension
3108 If set to "off", the debugger does not perform any script language
3109 recognition, and all sourced files are assumed to be GDB scripts.
3110 If set to "soft" (the default), files are sourced according to
3111 filename extension, falling back to GDB scripts if the first
3113 If set to "strict", files are sourced according to filename extension.
3115 set ada trust-PAD-over-XVS on|off
3116 show ada trust-PAD-over-XVS
3117 If off, activate a workaround against a bug in the debugging information
3118 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3119 the GCC sources for more information about the GNAT encoding and
3120 PAD types in particular). It is always safe to set this option to
3121 off, but this introduces a slight performance penalty. The default
3124 * Python API Improvements
3126 ** GDB provides the new class gdb.LazyString. This is useful in
3127 some pretty-printing cases. The new method gdb.Value.lazy_string
3128 provides a simple way to create objects of this type.
3130 ** The fields returned by gdb.Type.fields now have an
3131 `is_base_class' attribute.
3133 ** The new method gdb.Type.range returns the range of an array type.
3135 ** The new method gdb.parse_and_eval can be used to parse and
3136 evaluate an expression.
3138 * New remote packets
3141 Define a trace state variable.
3144 Get the current value of a trace state variable.
3147 Set desired tracing behavior upon disconnection.
3150 Set the trace buffer to be linear or circular.
3153 Get data about the tracepoints currently in use.
3157 Process record now works correctly with hardware watchpoints.
3159 Multiple bug fixes have been made to the mips-irix port, making it
3160 much more reliable. In particular:
3161 - Debugging threaded applications is now possible again. Previously,
3162 GDB would hang while starting the program, or while waiting for
3163 the program to stop at a breakpoint.
3164 - Attaching to a running process no longer hangs.
3165 - An error occurring while loading a core file has been fixed.
3166 - Changing the value of the PC register now works again. This fixes
3167 problems observed when using the "jump" command, or when calling
3168 a function from GDB, or even when assigning a new value to $pc.
3169 - With the "finish" and "return" commands, the return value for functions
3170 returning a small array is now correctly printed.
3171 - It is now possible to break on shared library code which gets executed
3172 during a shared library init phase (code executed while executing
3173 their .init section). Previously, the breakpoint would have no effect.
3174 - GDB is now able to backtrace through the signal handler for
3175 non-threaded programs.
3177 PIE (Position Independent Executable) programs debugging is now supported.
3178 This includes debugging execution of PIC (Position Independent Code) shared
3179 libraries although for that, it should be possible to run such libraries as an
3182 *** Changes in GDB 7.0
3184 * GDB now has an interface for JIT compilation. Applications that
3185 dynamically generate code can create symbol files in memory and register
3186 them with GDB. For users, the feature should work transparently, and
3187 for JIT developers, the interface is documented in the GDB manual in the
3188 "JIT Compilation Interface" chapter.
3190 * Tracepoints may now be conditional. The syntax is as for
3191 breakpoints; either an "if" clause appended to the "trace" command,
3192 or the "condition" command is available. GDB sends the condition to
3193 the target for evaluation using the same bytecode format as is used
3194 for tracepoint actions.
3196 * The disassemble command now supports: an optional /r modifier, print the
3197 raw instructions in hex as well as in symbolic form, and an optional /m
3198 modifier to print mixed source+assembly.
3200 * Process record and replay
3202 In a architecture environment that supports ``process record and
3203 replay'', ``process record and replay'' target can record a log of
3204 the process execution, and replay it with both forward and reverse
3207 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3208 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3209 set execution-direction {forward|reverse}, for targets that support
3212 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3213 feature is available with a native GDB running on kernel version
3216 * GDB now has support for multi-byte and wide character sets on the
3217 target. Strings whose character type is wchar_t, char16_t, or
3218 char32_t are now correctly printed. GDB supports wide- and unicode-
3219 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3220 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3221 `printf'. This feature requires iconv to work properly; if your
3222 system does not have a working iconv, GDB can use GNU libiconv. See
3223 the installation instructions for more information.
3225 * GDB now supports automatic retrieval of shared library files from
3226 remote targets. To use this feature, specify a system root that begins
3227 with the `remote:' prefix, either via the `set sysroot' command or via
3228 the `--with-sysroot' configure-time option.
3230 * "info sharedlibrary" now takes an optional regex of libraries to show,
3231 and it now reports if a shared library has no debugging information.
3233 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3234 now complete on file names.
3236 * When completing in expressions, gdb will attempt to limit
3237 completions to allowable structure or union fields, where appropriate.
3238 For instance, consider:
3240 # struct example { int f1; double f2; };
3241 # struct example variable;
3244 If the user types TAB at the end of this command line, the available
3245 completions will be "f1" and "f2".
3247 * Inlined functions are now supported. They show up in backtraces, and
3248 the "step", "next", and "finish" commands handle them automatically.
3250 * GDB now supports the token-splicing (##) and stringification (#)
3251 operators when expanding macros. It also supports variable-arity
3254 * GDB now supports inspecting extra signal information, exported by
3255 the new $_siginfo convenience variable. The feature is currently
3256 implemented on linux ARM, i386 and amd64.
3258 * GDB can now display the VFP floating point registers and NEON vector
3259 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3260 can provide these registers (requires Linux 2.6.30 or later). Remote
3261 and simulator targets may also provide them.
3263 * New remote packets
3266 Search memory for a sequence of bytes.
3269 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3270 operation over reliable transport links. Use of this packet is
3271 controlled by the `set remote noack-packet' command.
3274 Kill the process with the specified process ID. Use this in preference
3275 to `k' when multiprocess protocol extensions are supported.
3278 Obtains additional operating system information
3282 Read or write additional signal information.
3284 * Removed remote protocol undocumented extension
3286 An undocumented extension to the remote protocol's `S' stop reply
3287 packet that permited the stub to pass a process id was removed.
3288 Remote servers should use the `T' stop reply packet instead.
3290 * GDB now supports multiple function calling conventions according to the
3291 DWARF-2 DW_AT_calling_convention function attribute.
3293 * The SH target utilizes the aforementioned change to distinguish between gcc
3294 and Renesas calling convention. It also adds the new CLI commands
3295 `set/show sh calling-convention'.
3297 * GDB can now read compressed debug sections, as produced by GNU gold
3298 with the --compress-debug-sections=zlib flag.
3300 * 64-bit core files are now supported on AIX.
3302 * Thread switching is now supported on Tru64.
3304 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3305 which will be allocated using malloc later in program execution.
3307 * The qXfer:libraries:read remote procotol packet now allows passing a
3308 list of section offsets.
3310 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3311 conditions handling signals delivered during attach or thread creation
3312 have also been fixed.
3314 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3315 From the user's standpoint, all unqualified instances of True and False
3316 are treated as the standard definitions, regardless of context.
3318 * GDB now parses C++ symbol and type names more flexibly. For
3321 template<typename T> class C { };
3324 GDB will now correctly handle all of:
3326 ptype C<char const *>
3327 ptype C<char const*>
3328 ptype C<const char *>
3329 ptype C<const char*>
3331 * New features in the GDB remote stub, gdbserver
3333 - The "--wrapper" command-line argument tells gdbserver to use a
3334 wrapper program to launch programs for debugging.
3336 - On PowerPC and S/390 targets, it is now possible to use a single
3337 gdbserver executable to debug both 32-bit and 64-bit programs.
3338 (This requires gdbserver itself to be built as a 64-bit executable.)
3340 - gdbserver uses the new noack protocol mode for TCP connections to
3341 reduce communications latency, if also supported and enabled in GDB.
3343 - Support for the sparc64-linux-gnu target is now included in
3346 - The amd64-linux build of gdbserver now supports debugging both
3347 32-bit and 64-bit programs.
3349 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3350 now support hardware watchpoints, and will use them automatically
3355 GDB now has support for scripting using Python. Whether this is
3356 available is determined at configure time.
3358 New GDB commands can now be written in Python.
3360 * Ada tasking support
3362 Ada tasks can now be inspected in GDB. The following commands have
3366 Print the list of Ada tasks.
3368 Print detailed information about task number N.
3370 Print the task number of the current task.
3372 Switch the context of debugging to task number N.
3374 * Support for user-defined prefixed commands. The "define" command can
3375 add new commands to existing prefixes, e.g. "target".
3377 * Multi-inferior, multi-process debugging.
3379 GDB now has generalized support for multi-inferior debugging. See
3380 "Debugging Multiple Inferiors" in the manual for more information.
3381 Although availability still depends on target support, the command
3382 set is more uniform now. The GNU/Linux specific multi-forks support
3383 has been migrated to this new framework. This implied some user
3384 visible changes; see "New commands" and also "Removed commands"
3387 * Target descriptions can now describe the target OS ABI. See the
3388 "Target Description Format" section in the user manual for more
3391 * Target descriptions can now describe "compatible" architectures
3392 to indicate that the target can execute applications for a different
3393 architecture in addition to those for the main target architecture.
3394 See the "Target Description Format" section in the user manual for
3397 * Multi-architecture debugging.
3399 GDB now includes general supports for debugging applications on
3400 hybrid systems that use more than one single processor architecture
3401 at the same time. Each such hybrid architecture still requires
3402 specific support to be added. The only hybrid architecture supported
3403 in this version of GDB is the Cell Broadband Engine.
3405 * GDB now supports integrated debugging of Cell/B.E. applications that
3406 use both the PPU and SPU architectures. To enable support for hybrid
3407 Cell/B.E. debugging, you need to configure GDB to support both the
3408 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3409 --enable-targets configure option.
3411 * Non-stop mode debugging.
3413 For some targets, GDB now supports an optional mode of operation in
3414 which you can examine stopped threads while other threads continue
3415 to execute freely. This is referred to as non-stop mode, with the
3416 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3417 section in the user manual for more information.
3419 To be able to support remote non-stop debugging, a remote stub needs
3420 to implement the non-stop mode remote protocol extensions, as
3421 described in the "Remote Non-Stop" section of the user manual. The
3422 GDB remote stub, gdbserver, has been adjusted to support these
3423 extensions on linux targets.
3425 * New commands (for set/show, see "New options" below)
3427 catch syscall [NAME(S) | NUMBER(S)]
3428 Catch system calls. Arguments, which should be names of system
3429 calls or their numbers, mean catch only those syscalls. Without
3430 arguments, every syscall will be caught. When the inferior issues
3431 any of the specified syscalls, GDB will stop and announce the system
3432 call, both when it is called and when its call returns. This
3433 feature is currently available with a native GDB running on the
3434 Linux Kernel, under the following architectures: x86, x86_64,
3435 PowerPC and PowerPC64.
3437 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3439 Search memory for a sequence of bytes.
3441 maint set python print-stack
3442 maint show python print-stack
3443 Show a stack trace when an error is encountered in a Python script.
3446 Invoke CODE by passing it to the Python interpreter.
3451 These allow macros to be defined, undefined, and listed
3455 Show operating system information about processes.
3458 List the inferiors currently under GDB's control.
3461 Switch focus to inferior number NUM.
3464 Detach from inferior number NUM.
3467 Kill inferior number NUM.
3471 set spu stop-on-load
3472 show spu stop-on-load
3473 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3475 set spu auto-flush-cache
3476 show spu auto-flush-cache
3477 Control whether to automatically flush the software-managed cache
3478 during Cell/B.E. debugging.
3480 set sh calling-convention
3481 show sh calling-convention
3482 Control the calling convention used when calling SH target functions.
3485 show debug timestamp
3486 Control display of timestamps with GDB debugging output.
3488 set disassemble-next-line
3489 show disassemble-next-line
3490 Control display of disassembled source lines or instructions when
3493 set remote noack-packet
3494 show remote noack-packet
3495 Set/show the use of remote protocol QStartNoAckMode packet. See above
3496 under "New remote packets."
3498 set remote query-attached-packet
3499 show remote query-attached-packet
3500 Control use of remote protocol `qAttached' (query-attached) packet.
3502 set remote read-siginfo-object
3503 show remote read-siginfo-object
3504 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3507 set remote write-siginfo-object
3508 show remote write-siginfo-object
3509 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3512 set remote reverse-continue
3513 show remote reverse-continue
3514 Control use of remote protocol 'bc' (reverse-continue) packet.
3516 set remote reverse-step
3517 show remote reverse-step
3518 Control use of remote protocol 'bs' (reverse-step) packet.
3520 set displaced-stepping
3521 show displaced-stepping
3522 Control displaced stepping mode. Displaced stepping is a way to
3523 single-step over breakpoints without removing them from the debuggee.
3524 Also known as "out-of-line single-stepping".
3527 show debug displaced
3528 Control display of debugging info for displaced stepping.
3530 maint set internal-error
3531 maint show internal-error
3532 Control what GDB does when an internal error is detected.
3534 maint set internal-warning
3535 maint show internal-warning
3536 Control what GDB does when an internal warning is detected.
3541 Use a wrapper program to launch programs for debugging.
3543 set multiple-symbols (all|ask|cancel)
3544 show multiple-symbols
3545 The value of this variable can be changed to adjust the debugger behavior
3546 when an expression or a breakpoint location contains an ambiguous symbol
3547 name (an overloaded function name, for instance).
3549 set breakpoint always-inserted
3550 show breakpoint always-inserted
3551 Keep breakpoints always inserted in the target, as opposed to inserting
3552 them when resuming the target, and removing them when the target stops.
3553 This option can improve debugger performance on slow remote targets.
3555 set arm fallback-mode (arm|thumb|auto)
3556 show arm fallback-mode
3557 set arm force-mode (arm|thumb|auto)
3559 These commands control how ARM GDB determines whether instructions
3560 are ARM or Thumb. The default for both settings is auto, which uses
3561 the current CPSR value for instructions without symbols; previous
3562 versions of GDB behaved as if "set arm fallback-mode arm".
3564 set disable-randomization
3565 show disable-randomization
3566 Standalone programs run with the virtual address space randomization enabled
3567 by default on some platforms. This option keeps the addresses stable across
3568 multiple debugging sessions.
3572 Control whether other threads are stopped or not when some thread hits
3577 Requests that asynchronous execution is enabled in the target, if available.
3578 In this case, it's possible to resume target in the background, and interact
3579 with GDB while the target is running. "show target-async" displays the
3580 current state of asynchronous execution of the target.
3582 set target-wide-charset
3583 show target-wide-charset
3584 The target-wide-charset is the name of the character set that GDB
3585 uses when printing characters whose type is wchar_t.
3587 set tcp auto-retry (on|off)
3589 set tcp connect-timeout
3590 show tcp connect-timeout
3591 These commands allow GDB to retry failed TCP connections to a remote stub
3592 with a specified timeout period; this is useful if the stub is launched
3593 in parallel with GDB but may not be ready to accept connections immediately.
3595 set libthread-db-search-path
3596 show libthread-db-search-path
3597 Control list of directories which GDB will search for appropriate
3600 set schedule-multiple (on|off)
3601 show schedule-multiple
3602 Allow GDB to resume all threads of all processes or only threads of
3603 the current process.
3607 Use more aggressive caching for accesses to the stack. This improves
3608 performance of remote debugging (particularly backtraces) without
3609 affecting correctness.
3611 set interactive-mode (on|off|auto)
3612 show interactive-mode
3613 Control whether GDB runs in interactive mode (on) or not (off).
3614 When in interactive mode, GDB waits for the user to answer all
3615 queries. Otherwise, GDB does not wait and assumes the default
3616 answer. When set to auto (the default), GDB determines which
3617 mode to use based on the stdin settings.
3622 For program forks, this is replaced by the new more generic `info
3623 inferiors' command. To list checkpoints, you can still use the
3624 `info checkpoints' command, which was an alias for the `info forks'
3628 Replaced by the new `inferior' command. To switch between
3629 checkpoints, you can still use the `restart' command, which was an
3630 alias for the `fork' command.
3633 This is removed, since some targets don't have a notion of
3634 processes. To switch between processes, you can still use the
3635 `inferior' command using GDB's own inferior number.
3638 For program forks, this is replaced by the new more generic `kill
3639 inferior' command. To delete a checkpoint, you can still use the
3640 `delete checkpoint' command, which was an alias for the `delete
3644 For program forks, this is replaced by the new more generic `detach
3645 inferior' command. To detach a checkpoint, you can still use the
3646 `detach checkpoint' command, which was an alias for the `detach
3649 * New native configurations
3651 x86/x86_64 Darwin i[34567]86-*-darwin*
3653 x86_64 MinGW x86_64-*-mingw*
3657 Lattice Mico32 lm32-*
3658 x86 DICOS i[34567]86-*-dicos*
3659 x86_64 DICOS x86_64-*-dicos*
3662 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3663 (mingw32ce) debugging.
3669 These commands were actually not implemented on any target.
3671 *** Changes in GDB 6.8
3673 * New native configurations
3675 NetBSD/hppa hppa*-*netbsd*
3676 Xtensa GNU/Linux xtensa*-*-linux*
3680 NetBSD/hppa hppa*-*-netbsd*
3681 Xtensa GNU/Lunux xtensa*-*-linux*
3683 * Change in command line behavior -- corefiles vs. process ids.
3685 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3686 attaching to process NUMBER fails, GDB no longer attempts to open a
3687 core file named NUMBER. Attaching to a program using the -c option
3688 is no longer supported. Instead, use the '-p' or '--pid' options.
3690 * GDB can now be built as a native debugger for debugging Windows x86
3691 (mingw32) Portable Executable (PE) programs.
3693 * Pending breakpoints no longer change their number when their address
3696 * GDB now supports breakpoints with multiple locations,
3697 including breakpoints on C++ constructors, inside C++ templates,
3698 and in inlined functions.
3700 * GDB's ability to debug optimized code has been improved. GDB more
3701 accurately identifies function bodies and lexical blocks that occupy
3702 more than one contiguous range of addresses.
3704 * Target descriptions can now describe registers for PowerPC.
3706 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3707 registers on PowerPC targets.
3709 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3710 targets even when the libthread_db library is not available.
3712 * The GDB remote stub, gdbserver, now supports the new file transfer
3713 commands (remote put, remote get, and remote delete).
3715 * The GDB remote stub, gdbserver, now supports run and attach in
3716 extended-remote mode.
3718 * hppa*64*-*-hpux11* target broken
3719 The debugger is unable to start a program and fails with the following
3720 error: "Error trying to get information about dynamic linker".
3721 The gdb-6.7 release is also affected.
3723 * GDB now supports the --enable-targets= configure option to allow
3724 building a single GDB executable that supports multiple remote
3725 target architectures.
3727 * GDB now supports debugging C and C++ programs which use the
3728 Decimal Floating Point extension. In addition, the PowerPC target
3729 now has a set of pseudo-registers to inspect decimal float values
3730 stored in two consecutive float registers.
3732 * The -break-insert MI command can optionally create pending
3735 * Improved support for debugging Ada
3736 Many improvements to the Ada language support have been made. These
3738 - Better support for Ada2005 interface types
3739 - Improved handling of arrays and slices in general
3740 - Better support for Taft-amendment types
3741 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3743 - Improved command completion in Ada
3746 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3751 set print frame-arguments (all|scalars|none)
3752 show print frame-arguments
3753 The value of this variable can be changed to control which argument
3754 values should be printed by the debugger when displaying a frame.
3759 Transfer files to and from a remote target, and delete remote files.
3766 Transfer files to and from a remote target, and delete remote files.
3768 * New remote packets
3775 Open, close, read, write, and delete files on the remote system.
3778 Attach to an existing process on the remote system, in extended-remote
3782 Run a new process on the remote system, in extended-remote mode.
3784 *** Changes in GDB 6.7
3786 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3787 bfd, libiberty and opcodes, as revealed by static analysis donated by
3788 Coverity, Inc. (http://scan.coverity.com).
3790 * When looking up multiply-defined global symbols, GDB will now prefer the
3791 symbol definition in the current shared library if it was built using the
3792 -Bsymbolic linker option.
3794 * When the Text User Interface (TUI) is not configured, GDB will now
3795 recognize the -tui command-line option and print a message that the TUI
3798 * The GDB remote stub, gdbserver, now has lower overhead for high
3799 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3801 * GDB for MIPS targets now autodetects whether a remote target provides
3802 32-bit or 64-bit register values.
3804 * Support for C++ member pointers has been improved.
3806 * GDB now understands XML target descriptions, which specify the
3807 target's overall architecture. GDB can read a description from
3808 a local file or over the remote serial protocol.
3810 * Vectors of single-byte data use a new integer type which is not
3811 automatically displayed as character or string data.
3813 * The /s format now works with the print command. It displays
3814 arrays of single-byte integers and pointers to single-byte integers
3817 * Target descriptions can now describe target-specific registers,
3818 for architectures which have implemented the support (currently
3819 only ARM, M68K, and MIPS).
3821 * GDB and the GDB remote stub, gdbserver, now support the XScale
3824 * The GDB remote stub, gdbserver, has been updated to support
3825 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3826 has been rewritten to use the standard GDB remote protocol.
3828 * GDB can now step into C++ functions which are called through thunks.
3830 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3832 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3833 layout. It also supports a TextSeg= and DataSeg= response when only
3834 segment base addresses (rather than offsets) are available.
3836 * The /i format now outputs any trailing branch delay slot instructions
3837 immediately following the last instruction within the count specified.
3839 * The GDB remote protocol "T" stop reply packet now supports a
3840 "library" response. Combined with the new "qXfer:libraries:read"
3841 packet, this response allows GDB to debug shared libraries on targets
3842 where the operating system manages the list of loaded libraries (e.g.
3843 Windows and SymbianOS).
3845 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3846 (DLLs) on Windows and Windows CE targets.
3848 * GDB now supports a faster verification that a .debug file matches its binary
3849 according to its build-id signature, if the signature is present.
3855 Enable or disable hardware flow control (RTS/CTS) on the serial port
3856 when debugging using remote targets.
3858 set mem inaccessible-by-default
3859 show mem inaccessible-by-default
3860 If the target supplies a memory map, for instance via the remote
3861 protocol's "qXfer:memory-map:read" packet, setting this variable
3862 prevents GDB from accessing memory outside the memory map. This
3863 is useful for targets with memory mapped registers or which react
3864 badly to accesses of unmapped address space.
3866 set breakpoint auto-hw
3867 show breakpoint auto-hw
3868 If the target supplies a memory map, for instance via the remote
3869 protocol's "qXfer:memory-map:read" packet, setting this variable
3870 lets GDB use hardware breakpoints automatically for memory regions
3871 where it can not use software breakpoints. This covers both the
3872 "break" command and internal breakpoints used for other commands
3873 including "next" and "finish".
3876 catch exception unhandled
3877 Stop the program execution when Ada exceptions are raised.
3880 Stop the program execution when an Ada assertion failed.
3884 Set an alternate system root for target files. This is a more
3885 general version of "set solib-absolute-prefix", which is now
3886 an alias to "set sysroot".
3889 Provide extended SPU facility status information. This set of
3890 commands is available only when debugging the Cell/B.E. SPU
3893 * New native configurations
3895 OpenBSD/sh sh*-*openbsd*
3898 unset tdesc filename
3900 Use the specified local file as an XML target description, and do
3901 not query the target for its built-in description.
3905 OpenBSD/sh sh*-*-openbsd*
3906 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3907 Toshiba Media Processor mep-elf
3909 * New remote packets
3912 Ignore the specified signals; pass them directly to the debugged program
3913 without stopping other threads or reporting them to GDB.
3915 qXfer:features:read:
3916 Read an XML target description from the target, which describes its
3921 Read or write contents of an spufs file on the target system. These
3922 packets are available only on the Cell/B.E. SPU architecture.
3924 qXfer:libraries:read:
3925 Report the loaded shared libraries. Combined with new "T" packet
3926 response, this packet allows GDB to debug shared libraries on
3927 targets where the operating system manages the list of loaded
3928 libraries (e.g. Windows and SymbianOS).
3932 Support for these obsolete configurations has been removed.
3940 i[34567]86-*-lynxos*
3941 i[34567]86-*-netware*
3942 i[34567]86-*-sco3.2v5*
3943 i[34567]86-*-sco3.2v4*
3945 i[34567]86-*-sysv4.2*
3948 i[34567]86-*-unixware2*
3949 i[34567]86-*-unixware*
3958 * Other removed features
3965 Various m68k-only ROM monitors.
3972 Various Renesas ROM monitors and debugging interfaces for SH and
3977 Support for a Macraigor serial interface to on-chip debugging.
3978 GDB does not directly support the newer parallel or USB
3983 A debug information format. The predecessor to DWARF 2 and
3984 DWARF 3, which are still supported.
3986 Support for the HP aCC compiler on HP-UX/PA-RISC
3988 SOM-encapsulated symbolic debugging information, automatic
3989 invocation of pxdb, and the aCC custom C++ ABI. This does not
3990 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3991 with aCC can still be debugged on an assembly level.
3993 MIPS ".pdr" sections
3995 A MIPS-specific format used to describe stack frame layout
3996 in debugging information.
4000 GDB could work with an older version of Guile to debug
4001 the interpreter and Scheme programs running in it.
4003 set mips stack-arg-size
4004 set mips saved-gpreg-size
4006 Use "set mips abi" to control parameter passing for MIPS.
4008 *** Changes in GDB 6.6
4013 Cell Broadband Engine SPU spu-elf
4015 * GDB can now be configured as a cross-debugger targeting native Windows
4016 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4017 running on a Windows system over TCP/IP to debug Windows programs.
4019 * The GDB remote stub, gdbserver, has been updated to support Windows and
4020 Cygwin debugging. Both single-threaded and multi-threaded programs are
4023 * The "set trust-readonly-sections" command works again. This command was
4024 broken in GDB 6.3, 6.4, and 6.5.
4026 * The "load" command now supports writing to flash memory, if the remote
4027 stub provides the required support.
4029 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4030 longer requires symbolic debug information (e.g. DWARF-2).
4035 unset substitute-path
4036 show substitute-path
4037 Manage a list of substitution rules that GDB uses to rewrite the name
4038 of the directories where the sources are located. This can be useful
4039 for instance when the sources were moved to a different location
4040 between compilation and debugging.
4044 Print each CLI command as it is executed. Each command is prefixed with
4045 a number of `+' symbols representing the nesting depth.
4046 The source command now has a `-v' option to enable the same feature.
4050 The ARM Demon monitor support (RDP protocol, "target rdp").
4052 Kernel Object Display, an embedded debugging feature which only worked with
4053 an obsolete version of Cisco IOS.
4055 The 'set download-write-size' and 'show download-write-size' commands.
4057 * New remote packets
4060 Tell a stub about GDB client features, and request remote target features.
4061 The first feature implemented is PacketSize, which allows the target to
4062 specify the size of packets it can handle - to minimize the number of
4063 packets required and improve performance when connected to a remote
4067 Fetch an OS auxilliary vector from the remote stub. This packet is a
4068 more efficient replacement for qPart:auxv:read.
4070 qXfer:memory-map:read:
4071 Fetch a memory map from the remote stub, including information about
4072 RAM, ROM, and flash memory devices.
4077 Erase and program a flash memory device.
4079 * Removed remote packets
4082 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4083 used it, and only gdbserver implemented it.
4085 *** Changes in GDB 6.5
4089 Renesas M32C/M16C m32c-elf
4091 Morpho Technologies ms1 ms1-elf
4095 init-if-undefined Initialize a convenience variable, but
4096 only if it doesn't already have a value.
4098 The following commands are presently only implemented for native GNU/Linux:
4100 checkpoint Save a snapshot of the program state.
4102 restart <n> Return the program state to a
4103 previously saved state.
4105 info checkpoints List currently saved checkpoints.
4107 delete-checkpoint <n> Delete a previously saved checkpoint.
4109 set|show detach-on-fork Tell gdb whether to detach from a newly
4110 forked process, or to keep debugging it.
4112 info forks List forks of the user program that
4113 are available to be debugged.
4115 fork <n> Switch to debugging one of several
4116 forks of the user program that are
4117 available to be debugged.
4119 delete-fork <n> Delete a fork from the list of forks
4120 that are available to be debugged (and
4121 kill the forked process).
4123 detach-fork <n> Delete a fork from the list of forks
4124 that are available to be debugged (and
4125 allow the process to continue).
4129 Morpho Technologies ms2 ms1-elf
4131 * Improved Windows host support
4133 GDB now builds as a cross debugger hosted on i686-mingw32, including
4134 native console support, and remote communications using either
4135 network sockets or serial ports.
4137 * Improved Modula-2 language support
4139 GDB can now print most types in the Modula-2 syntax. This includes:
4140 basic types, set types, record types, enumerated types, range types,
4141 pointer types and ARRAY types. Procedure var parameters are correctly
4142 printed and hexadecimal addresses and character constants are also
4143 written in the Modula-2 syntax. Best results can be obtained by using
4144 GNU Modula-2 together with the -gdwarf-2 command line option.
4148 The ARM rdi-share module.
4150 The Netware NLM debug server.
4152 *** Changes in GDB 6.4
4154 * New native configurations
4156 OpenBSD/arm arm*-*-openbsd*
4157 OpenBSD/mips64 mips64-*-openbsd*
4161 Morpho Technologies ms1 ms1-elf
4163 * New command line options
4165 --batch-silent As for --batch, but totally silent.
4166 --return-child-result The debugger will exist with the same value
4167 the child (debugged) program exited with.
4168 --eval-command COMMAND, -ex COMMAND
4169 Execute a single GDB CLI command. This may be
4170 specified multiple times and in conjunction
4171 with the --command (-x) option.
4173 * Deprecated commands removed
4175 The following commands, that were deprecated in 2000, have been
4179 set|show arm disassembly-flavor set|show arm disassembler
4180 othernames set arm disassembler
4181 set|show remotedebug set|show debug remote
4182 set|show archdebug set|show debug arch
4183 set|show eventdebug set|show debug event
4186 * New BSD user-level threads support
4188 It is now possible to debug programs using the user-level threads
4189 library on OpenBSD and FreeBSD. Currently supported (target)
4192 FreeBSD/amd64 x86_64-*-freebsd*
4193 FreeBSD/i386 i386-*-freebsd*
4194 OpenBSD/i386 i386-*-openbsd*
4196 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4197 are not yet supported.
4199 * New support for Matsushita MN10300 w/sim added
4200 (Work in progress). mn10300-elf.
4202 * REMOVED configurations and files
4204 VxWorks and the XDR protocol *-*-vxworks
4205 Motorola MCORE mcore-*-*
4206 National Semiconductor NS32000 ns32k-*-*
4208 * New "set print array-indexes" command
4210 After turning this setting "on", GDB prints the index of each element
4211 when displaying arrays. The default is "off" to preserve the previous
4214 * VAX floating point support
4216 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4218 * User-defined command support
4220 In addition to using $arg0..$arg9 for argument passing, it is now possible
4221 to use $argc to determine now many arguments have been passed. See the
4222 section on user-defined commands in the user manual for more information.
4224 *** Changes in GDB 6.3:
4226 * New command line option
4228 GDB now accepts -l followed by a number to set the timeout for remote
4231 * GDB works with GCC -feliminate-dwarf2-dups
4233 GDB now supports a more compact representation of DWARF-2 debug
4234 information using DW_FORM_ref_addr references. These are produced
4235 by GCC with the option -feliminate-dwarf2-dups and also by some
4236 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4237 to use -feliminate-dwarf2-dups.
4239 * Internationalization
4241 When supported by the host system, GDB will be built with
4242 internationalization (libintl). The task of marking up the sources is
4243 continued, we're looking forward to our first translation.
4247 Initial support for debugging programs compiled with the GNAT
4248 implementation of the Ada programming language has been integrated
4249 into GDB. In this release, support is limited to expression evaluation.
4251 * New native configurations
4253 GNU/Linux/m32r m32r-*-linux-gnu
4257 GDB's remote protocol now includes support for the 'p' packet. This
4258 packet is used to fetch individual registers from a remote inferior.
4260 * END-OF-LIFE registers[] compatibility module
4262 GDB's internal register infrastructure has been completely rewritten.
4263 The new infrastructure making possible the implementation of key new
4264 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4267 GDB 6.3 will be the last release to include the the registers[]
4268 compatibility module that allowed out-of-date configurations to
4269 continue to work. This change directly impacts the following
4279 powerpc bdm protocol
4281 Unless there is activity to revive these configurations, they will be
4282 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4284 * OBSOLETE configurations and files
4286 Configurations that have been declared obsolete in this release have
4287 been commented out. Unless there is activity to revive these
4288 configurations, the next release of GDB will have their sources
4289 permanently REMOVED.
4298 *** Changes in GDB 6.2.1:
4300 * MIPS `break main; run' gave an heuristic-fence-post warning
4302 When attempting to run even a simple program, a warning about
4303 heuristic-fence-post being hit would be reported. This problem has
4306 * MIPS IRIX 'long double' crashed GDB
4308 When examining a long double variable, GDB would get a segmentation
4309 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4310 IRIX long double values).
4314 A bug in the VAX stack code was causing problems with the "next"
4315 command. This problem has been fixed.
4317 *** Changes in GDB 6.2:
4319 * Fix for ``many threads''
4321 On GNU/Linux systems that use the NPTL threads library, a program
4322 rapidly creating and deleting threads would confuse GDB leading to the
4325 ptrace: No such process.
4326 thread_db_get_info: cannot get thread info: generic error
4328 This problem has been fixed.
4330 * "-async" and "-noasync" options removed.
4332 Support for the broken "-noasync" option has been removed (it caused
4335 * New ``start'' command.
4337 This command runs the program until the begining of the main procedure.
4339 * New BSD Kernel Data Access Library (libkvm) interface
4341 Using ``target kvm'' it is now possible to debug kernel core dumps and
4342 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4343 platforms. Currently supported (native-only) configurations are:
4345 FreeBSD/amd64 x86_64-*-freebsd*
4346 FreeBSD/i386 i?86-*-freebsd*
4347 NetBSD/i386 i?86-*-netbsd*
4348 NetBSD/m68k m68*-*-netbsd*
4349 NetBSD/sparc sparc-*-netbsd*
4350 OpenBSD/amd64 x86_64-*-openbsd*
4351 OpenBSD/i386 i?86-*-openbsd*
4352 OpenBSD/m68k m68*-openbsd*
4353 OpenBSD/sparc sparc-*-openbsd*
4355 * Signal trampoline code overhauled
4357 Many generic problems with GDB's signal handling code have been fixed.
4358 These include: backtraces through non-contiguous stacks; recognition
4359 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4360 call; backtrace through a signal trampoline; step into and out of
4361 signal handlers; and single-stepping in the signal trampoline.
4363 Please note that kernel bugs are a limiting factor here. These
4364 features have been shown to work on an s390 GNU/Linux system that
4365 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4367 * Cygwin support for DWARF 2 added.
4369 * New native configurations
4371 GNU/Linux/hppa hppa*-*-linux*
4372 OpenBSD/hppa hppa*-*-openbsd*
4373 OpenBSD/m68k m68*-*-openbsd*
4374 OpenBSD/m88k m88*-*-openbsd*
4375 OpenBSD/powerpc powerpc-*-openbsd*
4376 NetBSD/vax vax-*-netbsd*
4377 OpenBSD/vax vax-*-openbsd*
4379 * END-OF-LIFE frame compatibility module
4381 GDB's internal frame infrastructure has been completely rewritten.
4382 The new infrastructure making it possible to support key new features
4383 including DWARF 2 Call Frame Information. To aid in the task of
4384 migrating old configurations to this new infrastructure, a
4385 compatibility module, that allowed old configurations to continue to
4386 work, was also included.
4388 GDB 6.2 will be the last release to include this frame compatibility
4389 module. This change directly impacts the following configurations:
4399 Unless there is activity to revive these configurations, they will be
4400 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4402 * REMOVED configurations and files
4404 Sun 3, running SunOS 3 m68*-*-sunos3*
4405 Sun 3, running SunOS 4 m68*-*-sunos4*
4406 Sun 2, running SunOS 3 m68000-*-sunos3*
4407 Sun 2, running SunOS 4 m68000-*-sunos4*
4408 Motorola 680x0 running LynxOS m68*-*-lynxos*
4409 AT&T 3b1/Unix pc m68*-att-*
4410 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4411 decstation mips-dec-* mips-little-*
4412 riscos mips-*-riscos* mips-*-sysv*
4413 sonymips mips-sony-*
4414 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4416 *** Changes in GDB 6.1.1:
4418 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4420 The TUI (Text-mode User Interface) is now built as part of a default
4421 GDB configuration. It is enabled by either selecting the TUI with the
4422 command line option "-i=tui" or by running the separate "gdbtui"
4423 program. For more information on the TUI, see the manual "Debugging
4426 * Pending breakpoint support (also included in GDB 6.1)
4428 Support has been added to allow you to specify breakpoints in shared
4429 libraries that have not yet been loaded. If a breakpoint location
4430 cannot be found, and the "breakpoint pending" option is set to auto,
4431 GDB queries you if you wish to make the breakpoint pending on a future
4432 shared-library load. If and when GDB resolves the breakpoint symbol,
4433 the pending breakpoint is removed as one or more regular breakpoints
4436 Pending breakpoints are very useful for GCJ Java debugging.
4438 * Fixed ISO-C build problems
4440 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4441 non ISO-C code that stopped them being built using a more strict ISO-C
4442 compiler (e.g., IBM's C compiler).
4444 * Fixed build problem on IRIX 5
4446 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4447 wasn't able to compile compile on an IRIX 5 system.
4449 * Added execute permission to gdb/gdbserver/configure
4451 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4452 permission. This bug would cause configure to fail on a number of
4453 systems (Solaris, IRIX). Ref: server/519.
4455 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4457 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4458 has been updated to use constant array sizes.
4460 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4462 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4463 its generated DWARF Call Frame Info. This encoding was causing GDB to
4464 panic, that panic has been fixed. Ref: gdb/1628.
4466 * Fixed a problem when examining parameters in shared library code.
4468 When examining parameters in optimized shared library code generated
4469 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4470 not available''. GDB now correctly displays the variable's value.
4472 *** Changes in GDB 6.1:
4474 * Removed --with-mmalloc
4476 Support for the mmalloc memory manager has been removed, as it
4477 conflicted with the internal gdb byte cache.
4479 * Changes in AMD64 configurations
4481 The AMD64 target now includes the %cs and %ss registers. As a result
4482 the AMD64 remote protocol has changed; this affects the floating-point
4483 and SSE registers. If you rely on those registers for your debugging,
4484 you should upgrade gdbserver on the remote side.
4486 * Revised SPARC target
4488 The SPARC target has been completely revised, incorporating the
4489 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4490 support for LynxOS and SunOS 4 has been dropped. Calling functions
4491 from within GDB on operating systems with a non-executable stack
4492 (Solaris, OpenBSD) now works.
4496 GDB has a new C++ demangler which does a better job on the mangled
4497 names generated by current versions of g++. It also runs faster, so
4498 with this and other changes gdb should now start faster on large C++
4501 * DWARF 2 Location Expressions
4503 GDB support for location expressions has been extended to support function
4504 arguments and frame bases. Older versions of GDB could crash when they
4507 * C++ nested types and namespaces
4509 GDB's support for nested types and namespaces in C++ has been
4510 improved, especially if you use the DWARF 2 debugging format. (This
4511 is the default for recent versions of GCC on most platforms.)
4512 Specifically, if you have a class "Inner" defined within a class or
4513 namespace "Outer", then GDB realizes that the class's name is
4514 "Outer::Inner", not simply "Inner". This should greatly reduce the
4515 frequency of complaints about not finding RTTI symbols. In addition,
4516 if you are stopped at inside of a function defined within a namespace,
4517 GDB modifies its name lookup accordingly.
4519 * New native configurations
4521 NetBSD/amd64 x86_64-*-netbsd*
4522 OpenBSD/amd64 x86_64-*-openbsd*
4523 OpenBSD/alpha alpha*-*-openbsd*
4524 OpenBSD/sparc sparc-*-openbsd*
4525 OpenBSD/sparc64 sparc64-*-openbsd*
4527 * New debugging protocols
4529 M32R with SDI protocol m32r-*-elf*
4531 * "set prompt-escape-char" command deleted.
4533 The command "set prompt-escape-char" has been deleted. This command,
4534 and its very obscure effet on GDB's prompt, was never documented,
4535 tested, nor mentioned in the NEWS file.
4537 * OBSOLETE configurations and files
4539 Configurations that have been declared obsolete in this release have
4540 been commented out. Unless there is activity to revive these
4541 configurations, the next release of GDB will have their sources
4542 permanently REMOVED.
4544 Sun 3, running SunOS 3 m68*-*-sunos3*
4545 Sun 3, running SunOS 4 m68*-*-sunos4*
4546 Sun 2, running SunOS 3 m68000-*-sunos3*
4547 Sun 2, running SunOS 4 m68000-*-sunos4*
4548 Motorola 680x0 running LynxOS m68*-*-lynxos*
4549 AT&T 3b1/Unix pc m68*-att-*
4550 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4551 decstation mips-dec-* mips-little-*
4552 riscos mips-*-riscos* mips-*-sysv*
4553 sonymips mips-sony-*
4554 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4556 * REMOVED configurations and files
4558 SGI Irix-4.x mips-sgi-irix4 or iris4
4559 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4560 Z8000 simulator z8k-zilog-none or z8ksim
4561 Matsushita MN10200 w/simulator mn10200-*-*
4562 H8/500 simulator h8500-hitachi-hms or h8500hms
4563 HP/PA running BSD hppa*-*-bsd*
4564 HP/PA running OSF/1 hppa*-*-osf*
4565 HP/PA Pro target hppa*-*-pro*
4566 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4567 386BSD i[3456]86-*-bsd*
4568 Sequent family i[3456]86-sequent-sysv4*
4569 i[3456]86-sequent-sysv*
4570 i[3456]86-sequent-bsd*
4571 SPARC running LynxOS sparc-*-lynxos*
4572 SPARC running SunOS 4 sparc-*-sunos4*
4573 Tsqware Sparclet sparclet-*-*
4574 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4576 *** Changes in GDB 6.0:
4580 Support for debugging the Objective-C programming language has been
4581 integrated into GDB.
4583 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4585 DWARF 2's Call Frame Information makes available compiler generated
4586 information that more exactly describes the program's run-time stack.
4587 By using this information, GDB is able to provide more robust stack
4590 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4591 have been updated to use a new backtrace mechanism which includes
4592 DWARF 2 CFI support.
4596 GDB's remote protocol has been extended to include support for hosted
4597 file I/O (where the remote target uses GDB's file system). See GDB's
4598 remote protocol documentation for details.
4600 * All targets using the new architecture framework.
4602 All of GDB's targets have been updated to use the new internal
4603 architecture framework. The way is now open for future GDB releases
4604 to include cross-architecture native debugging support (i386 on amd64,
4607 * GNU/Linux's Thread Local Storage (TLS)
4609 GDB now includes support for for the GNU/Linux implementation of
4610 per-thread variables.
4612 * GNU/Linux's Native POSIX Thread Library (NPTL)
4614 GDB's thread code has been updated to work with either the new
4615 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4617 * Separate debug info.
4619 GDB, in conjunction with BINUTILS, now supports a mechanism for
4620 automatically loading debug information from a separate file. Instead
4621 of shipping full debug and non-debug versions of system libraries,
4622 system integrators can now instead ship just the stripped libraries
4623 and optional debug files.
4625 * DWARF 2 Location Expressions
4627 DWARF 2 Location Expressions allow the compiler to more completely
4628 describe the location of variables (even in optimized code) to the
4631 GDB now includes preliminary support for location expressions (support
4632 for DW_OP_piece is still missing).
4636 A number of long standing bugs that caused GDB to die while starting a
4637 Java application have been fixed. GDB's Java support is now
4638 considered "useable".
4640 * GNU/Linux support for fork, vfork, and exec.
4642 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4643 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4646 * GDB supports logging output to a file
4648 There are two new commands, "set logging" and "show logging", which can be
4649 used to capture GDB's output to a file.
4651 * The meaning of "detach" has changed for gdbserver
4653 The "detach" command will now resume the application, as documented. To
4654 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4657 * d10v, m68hc11 `regs' command deprecated
4659 The `info registers' command has been updated so that it displays the
4660 registers using a format identical to the old `regs' command.
4664 A new command, "maint set profile on/off", has been added. This command can
4665 be used to enable or disable profiling while running GDB, to profile a
4666 session or a set of commands. In addition there is a new configure switch,
4667 "--enable-profiling", which will cause GDB to be compiled with profiling
4668 data, for more informative profiling results.
4670 * Default MI syntax changed to "mi2".
4672 The default MI (machine interface) syntax, enabled by the command line
4673 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4674 "mi1", can be enabled by specifying the option "-i=mi1".
4676 Support for the original "mi0" syntax (included in GDB 5.0) has been
4679 Fix for gdb/192: removed extraneous space when displaying frame level.
4680 Fix for gdb/672: update changelist is now output in mi list format.
4681 Fix for gdb/702: a -var-assign that updates the value now shows up
4682 in a subsequent -var-update.
4684 * New native configurations.
4686 FreeBSD/amd64 x86_64-*-freebsd*
4688 * Multi-arched targets.
4690 HP/PA HPUX11 hppa*-*-hpux*
4691 Renesas M32R/D w/simulator m32r-*-elf*
4693 * OBSOLETE configurations and files
4695 Configurations that have been declared obsolete in this release have
4696 been commented out. Unless there is activity to revive these
4697 configurations, the next release of GDB will have their sources
4698 permanently REMOVED.
4700 Z8000 simulator z8k-zilog-none or z8ksim
4701 Matsushita MN10200 w/simulator mn10200-*-*
4702 H8/500 simulator h8500-hitachi-hms or h8500hms
4703 HP/PA running BSD hppa*-*-bsd*
4704 HP/PA running OSF/1 hppa*-*-osf*
4705 HP/PA Pro target hppa*-*-pro*
4706 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4707 Sequent family i[3456]86-sequent-sysv4*
4708 i[3456]86-sequent-sysv*
4709 i[3456]86-sequent-bsd*
4710 Tsqware Sparclet sparclet-*-*
4711 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4713 * REMOVED configurations and files
4716 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4717 IBM AIX PS/2 i[3456]86-*-aix
4718 i386 running Mach 3.0 i[3456]86-*-mach3*
4719 i386 running Mach i[3456]86-*-mach*
4720 i386 running OSF/1 i[3456]86-*osf1mk*
4721 HP/Apollo 68k Family m68*-apollo*-sysv*,
4723 m68*-hp-bsd*, m68*-hp-hpux*
4724 Argonaut Risc Chip (ARC) arc-*-*
4725 Mitsubishi D30V d30v-*-*
4726 Fujitsu FR30 fr30-*-elf*
4727 OS/9000 i[34]86-*-os9k
4728 I960 with MON960 i960-*-coff
4730 * MIPS $fp behavior changed
4732 The convenience variable $fp, for the MIPS, now consistently returns
4733 the address of the current frame's base. Previously, depending on the
4734 context, $fp could refer to either $sp or the current frame's base
4735 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4736 The GNU Source-Level Debugger''.
4738 *** Changes in GDB 5.3:
4740 * GNU/Linux shared library multi-threaded performance improved.
4742 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4743 `/proc', in preference to `ptrace' for memory reads. This may result
4744 in an improvement in the start-up time of multi-threaded, shared
4745 library applications when run under GDB. One GDB user writes: ``loads
4746 shared libs like mad''.
4748 * ``gdbserver'' now supports multi-threaded applications on some targets
4750 Support for debugging multi-threaded applications which use
4751 the GNU/Linux LinuxThreads package has been added for
4752 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4753 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4755 * GDB now supports C/C++ preprocessor macros.
4757 GDB now expands preprocessor macro invocations in C/C++ expressions,
4758 and provides various commands for showing macro definitions and how
4761 The new command `macro expand EXPRESSION' expands any macro
4762 invocations in expression, and shows the result.
4764 The new command `show macro MACRO-NAME' shows the definition of the
4765 macro named MACRO-NAME, and where it was defined.
4767 Most compilers don't include information about macros in the debugging
4768 information by default. In GCC 3.1, for example, you need to compile
4769 your program with the options `-gdwarf-2 -g3'. If the macro
4770 information is present in the executable, GDB will read it.
4772 * Multi-arched targets.
4774 DEC Alpha (partial) alpha*-*-*
4775 DEC VAX (partial) vax-*-*
4777 National Semiconductor NS32000 (partial) ns32k-*-*
4778 Motorola 68000 (partial) m68k-*-*
4779 Motorola MCORE mcore-*-*
4783 Fujitsu FRV architecture added by Red Hat frv*-*-*
4786 * New native configurations
4788 Alpha NetBSD alpha*-*-netbsd*
4789 SH NetBSD sh*-*-netbsdelf*
4790 MIPS NetBSD mips*-*-netbsd*
4791 UltraSPARC NetBSD sparc64-*-netbsd*
4793 * OBSOLETE configurations and files
4795 Configurations that have been declared obsolete in this release have
4796 been commented out. Unless there is activity to revive these
4797 configurations, the next release of GDB will have their sources
4798 permanently REMOVED.
4800 Mitsubishi D30V d30v-*-*
4801 OS/9000 i[34]86-*-os9k
4802 IBM AIX PS/2 i[3456]86-*-aix
4803 Fujitsu FR30 fr30-*-elf*
4804 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4805 Argonaut Risc Chip (ARC) arc-*-*
4806 i386 running Mach 3.0 i[3456]86-*-mach3*
4807 i386 running Mach i[3456]86-*-mach*
4808 i386 running OSF/1 i[3456]86-*osf1mk*
4809 HP/Apollo 68k Family m68*-apollo*-sysv*,
4811 m68*-hp-bsd*, m68*-hp-hpux*
4812 I960 with MON960 i960-*-coff
4814 * OBSOLETE languages
4816 CHILL, a Pascal like language used by telecommunications companies.
4818 * REMOVED configurations and files
4820 AMD 29k family via UDI a29k-amd-udi, udi29k
4821 A29K VxWorks a29k-*-vxworks
4822 AMD 29000 embedded, using EBMON a29k-none-none
4823 AMD 29000 embedded with COFF a29k-none-coff
4824 AMD 29000 embedded with a.out a29k-none-aout
4826 testsuite/gdb.hp/gdb.threads-hp/ directory
4828 * New command "set max-user-call-depth <nnn>"
4830 This command allows the user to limit the call depth of user-defined
4831 commands. The default is 1024.
4833 * Changes in FreeBSD/i386 native debugging.
4835 Support for the "generate-core-file" has been added.
4837 * New commands "dump", "append", and "restore".
4839 These commands allow data to be copied from target memory
4840 to a bfd-format or binary file (dump and append), and back
4841 from a file into memory (restore).
4843 * Improved "next/step" support on multi-processor Alpha Tru64.
4845 The previous single-step mechanism could cause unpredictable problems,
4846 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4847 of a software single-step mechanism prevents this.
4849 *** Changes in GDB 5.2.1:
4857 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4858 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4859 Fix, by Joel Brobecker imported from mainline.
4861 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4862 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4863 Fix, by Fred Fish, imported from mainline.
4865 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4866 Surprisingly enough, it works now.
4867 By Michal Ludvig, imported from mainline.
4869 i386 hardware watchpoint support:
4870 avoid misses on second run for some targets.
4871 By Pierre Muller, imported from mainline.
4873 *** Changes in GDB 5.2:
4875 * New command "set trust-readonly-sections on[off]".
4877 This command is a hint that tells gdb that read-only sections
4878 really are read-only (ie. that their contents will not change).
4879 In this mode, gdb will go to the object file rather than the
4880 target to read memory from read-only sections (such as ".text").
4881 This can be a significant performance improvement on some
4882 (notably embedded) targets.
4884 * New command "generate-core-file" (or "gcore").
4886 This new gdb command allows the user to drop a core file of the child
4887 process state at any time. So far it's been implemented only for
4888 GNU/Linux and Solaris, but should be relatively easily ported to other
4889 hosts. Argument is core file name (defaults to core.<pid>).
4891 * New command line option
4893 GDB now accepts --pid or -p followed by a process id.
4895 * Change in command line behavior -- corefiles vs. process ids.
4897 There is a subtle behavior in the way in which GDB handles
4898 command line arguments. The first non-flag argument is always
4899 a program to debug, but the second non-flag argument may either
4900 be a corefile or a process id. Previously, GDB would attempt to
4901 open the second argument as a corefile, and if that failed, would
4902 issue a superfluous error message and then attempt to attach it as
4903 a process. Now, if the second argument begins with a non-digit,
4904 it will be treated as a corefile. If it begins with a digit,
4905 GDB will attempt to attach it as a process, and if no such process
4906 is found, will then attempt to open it as a corefile.
4908 * Changes in ARM configurations.
4910 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4911 configuration is fully multi-arch.
4913 * New native configurations
4915 ARM NetBSD arm*-*-netbsd*
4916 x86 OpenBSD i[3456]86-*-openbsd*
4917 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4918 Sparc64 running FreeBSD sparc64-*-freebsd*
4922 Sanyo XStormy16 xstormy16-elf
4924 * OBSOLETE configurations and files
4926 Configurations that have been declared obsolete in this release have
4927 been commented out. Unless there is activity to revive these
4928 configurations, the next release of GDB will have their sources
4929 permanently REMOVED.
4931 AMD 29k family via UDI a29k-amd-udi, udi29k
4932 A29K VxWorks a29k-*-vxworks
4933 AMD 29000 embedded, using EBMON a29k-none-none
4934 AMD 29000 embedded with COFF a29k-none-coff
4935 AMD 29000 embedded with a.out a29k-none-aout
4937 testsuite/gdb.hp/gdb.threads-hp/ directory
4939 * REMOVED configurations and files
4941 TI TMS320C80 tic80-*-*
4943 PowerPC Solaris powerpcle-*-solaris*
4944 PowerPC Windows NT powerpcle-*-cygwin32
4945 PowerPC Netware powerpc-*-netware*
4946 Harris/CXUX m88k m88*-harris-cxux*
4947 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4948 ns32k-utek-sysv* ns32k-utek-*
4949 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4950 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4951 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4952 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4953 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4955 * Changes to command line processing
4957 The new `--args' feature can be used to specify command-line arguments
4958 for the inferior from gdb's command line.
4960 * Changes to key bindings
4962 There is a new `operate-and-get-next' function bound to `C-o'.
4964 *** Changes in GDB 5.1.1
4966 Fix compile problem on DJGPP.
4968 Fix a problem with floating-point registers on the i386 being
4971 Fix to stop GDB crashing on .debug_str debug info.
4973 Numerous documentation fixes.
4975 Numerous testsuite fixes.
4977 *** Changes in GDB 5.1:
4979 * New native configurations
4981 Alpha FreeBSD alpha*-*-freebsd*
4982 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4983 MIPS GNU/Linux mips*-*-linux*
4984 MIPS SGI Irix 6.x mips*-sgi-irix6*
4985 ia64 AIX ia64-*-aix*
4986 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4990 Motorola 68HC11 and 68HC12 m68hc11-elf
4992 UltraSparc running GNU/Linux sparc64-*-linux*
4994 * OBSOLETE configurations and files
4996 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4997 Harris/CXUX m88k m88*-harris-cxux*
4998 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4999 ns32k-utek-sysv* ns32k-utek-*
5000 TI TMS320C80 tic80-*-*
5002 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5003 PowerPC Solaris powerpcle-*-solaris*
5004 PowerPC Windows NT powerpcle-*-cygwin32
5005 PowerPC Netware powerpc-*-netware*
5006 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5007 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5008 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5009 Apple Macintosh (MPW) host N/A
5011 stuff.c (Program to stuff files into a specially prepared space in kdb)
5012 kdb-start.c (Main loop for the standalone kernel debugger)
5014 Configurations that have been declared obsolete in this release have
5015 been commented out. Unless there is activity to revive these
5016 configurations, the next release of GDB will have their sources
5017 permanently REMOVED.
5019 * REMOVED configurations and files
5021 Altos 3068 m68*-altos-*
5022 Convex c1-*-*, c2-*-*
5024 ARM RISCix arm-*-* (as host)
5028 * GDB has been converted to ISO C.
5030 GDB's source code has been converted to ISO C. In particular, the
5031 sources are fully protoized, and rely on standard headers being
5036 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5038 * The MI enabled by default.
5040 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5041 revised and enabled by default. Packages which use GDB as a debugging
5042 engine behind a UI or another front end are encouraged to switch to
5043 using the GDB/MI interface, instead of the old annotations interface
5044 which is now deprecated.
5046 * Support for debugging Pascal programs.
5048 GDB now includes support for debugging Pascal programs. The following
5049 main features are supported:
5051 - Pascal-specific data types such as sets;
5053 - automatic recognition of Pascal sources based on file-name
5056 - Pascal-style display of data types, variables, and functions;
5058 - a Pascal expression parser.
5060 However, some important features are not yet supported.
5062 - Pascal string operations are not supported at all;
5064 - there are some problems with boolean types;
5066 - Pascal type hexadecimal constants are not supported
5067 because they conflict with the internal variables format;
5069 - support for Pascal objects and classes is not full yet;
5071 - unlike Pascal, GDB is case-sensitive for symbol names.
5073 * Changes in completion.
5075 Commands such as `shell', `run' and `set args', which pass arguments
5076 to inferior programs, now complete on file names, similar to what
5077 users expect at the shell prompt.
5079 Commands which accept locations, such as `disassemble', `print',
5080 `breakpoint', `until', etc. now complete on filenames as well as
5081 program symbols. Thus, if you type "break foob TAB", and the source
5082 files linked into the programs include `foobar.c', that file name will
5083 be one of the candidates for completion. However, file names are not
5084 considered for completion after you typed a colon that delimits a file
5085 name from a name of a function in that file, as in "break foo.c:bar".
5087 `set demangle-style' completes on available demangling styles.
5089 * New platform-independent commands:
5091 It is now possible to define a post-hook for a command as well as a
5092 hook that runs before the command. For more details, see the
5093 documentation of `hookpost' in the GDB manual.
5095 * Changes in GNU/Linux native debugging.
5097 Support for debugging multi-threaded programs has been completely
5098 revised for all platforms except m68k and sparc. You can now debug as
5099 many threads as your system allows you to have.
5101 Attach/detach is supported for multi-threaded programs.
5103 Support for SSE registers was added for x86. This doesn't work for
5104 multi-threaded programs though.
5106 * Changes in MIPS configurations.
5108 Multi-arch support is enabled for all MIPS configurations.
5110 GDB can now be built as native debugger on SGI Irix 6.x systems for
5111 debugging n32 executables. (Debugging 64-bit executables is not yet
5114 * Unified support for hardware watchpoints in all x86 configurations.
5116 Most (if not all) native x86 configurations support hardware-assisted
5117 breakpoints and watchpoints in a unified manner. This support
5118 implements debug register sharing between watchpoints, which allows to
5119 put a virtually infinite number of watchpoints on the same address,
5120 and also supports watching regions up to 16 bytes with several debug
5123 The new maintenance command `maintenance show-debug-regs' toggles
5124 debugging print-outs in functions that insert, remove, and test
5125 watchpoints and hardware breakpoints.
5127 * Changes in the DJGPP native configuration.
5129 New command ``info dos sysinfo'' displays assorted information about
5130 the CPU, OS, memory, and DPMI server.
5132 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5133 display information about segment descriptors stored in GDT, LDT, and
5136 New commands ``info dos pde'' and ``info dos pte'' display entries
5137 from Page Directory and Page Tables (for now works with CWSDPMI only).
5138 New command ``info dos address-pte'' displays the Page Table entry for
5139 a given linear address.
5141 GDB can now pass command lines longer than 126 characters to the
5142 program being debugged (requires an update to the libdbg.a library
5143 which is part of the DJGPP development kit).
5145 DWARF2 debug info is now supported.
5147 It is now possible to `step' and `next' through calls to `longjmp'.
5149 * Changes in documentation.
5151 All GDB documentation was converted to GFDL, the GNU Free
5152 Documentation License.
5154 Tracepoints-related commands are now fully documented in the GDB
5157 TUI, the Text-mode User Interface, is now documented in the manual.
5159 Tracepoints-related commands are now fully documented in the GDB
5162 The "GDB Internals" manual now has an index. It also includes
5163 documentation of `ui_out' functions, GDB coding standards, x86
5164 hardware watchpoints, and memory region attributes.
5166 * GDB's version number moved to ``version.in''
5168 The Makefile variable VERSION has been replaced by the file
5169 ``version.in''. People creating GDB distributions should update the
5170 contents of this file.
5174 GUD support is now a standard part of the EMACS distribution.
5176 *** Changes in GDB 5.0:
5178 * Improved support for debugging FP programs on x86 targets
5180 Unified and much-improved support for debugging floating-point
5181 programs on all x86 targets. In particular, ``info float'' now
5182 displays the FP registers in the same format on all x86 targets, with
5183 greater level of detail.
5185 * Improvements and bugfixes in hardware-assisted watchpoints
5187 It is now possible to watch array elements, struct members, and
5188 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5189 on x86 targets no longer erroneously trigger when the address is
5192 * Improvements in the native DJGPP version of GDB
5194 The distribution now includes all the scripts and auxiliary files
5195 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5196 machines ``out of the box''.
5198 The DJGPP version can now debug programs that use signals. It is
5199 possible to catch signals that happened in the debuggee, deliver
5200 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5201 would kill the program being debugged.) Programs that hook hardware
5202 interrupts (keyboard, timer, etc.) can also be debugged.
5204 It is now possible to debug DJGPP programs that redirect their
5205 standard handles or switch them to raw (as opposed to cooked) mode, or
5206 even close them. The command ``run < foo > bar'' works as expected,
5207 and ``info terminal'' reports useful information about the debuggee's
5208 terminal, including raw/cooked mode, redirection, etc.
5210 The DJGPP version now uses termios functions for console I/O, which
5211 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5214 DOS-style file names with drive letters are now fully supported by
5217 It is now possible to debug DJGPP programs that switch their working
5218 directory. It is also possible to rerun the debuggee any number of
5219 times without restarting GDB; thus, you can use the same setup,
5220 breakpoints, etc. for many debugging sessions.
5222 * New native configurations
5224 ARM GNU/Linux arm*-*-linux*
5225 PowerPC GNU/Linux powerpc-*-linux*
5229 Motorola MCore mcore-*-*
5230 x86 VxWorks i[3456]86-*-vxworks*
5231 PowerPC VxWorks powerpc-*-vxworks*
5232 TI TMS320C80 tic80-*-*
5234 * OBSOLETE configurations
5236 Altos 3068 m68*-altos-*
5237 Convex c1-*-*, c2-*-*
5239 ARM RISCix arm-*-* (as host)
5242 Configurations that have been declared obsolete will be commented out,
5243 but the code will be left in place. If there is no activity to revive
5244 these configurations before the next release of GDB, the sources will
5245 be permanently REMOVED.
5247 * Gould support removed
5249 Support for the Gould PowerNode and NP1 has been removed.
5251 * New features for SVR4
5253 On SVR4 native platforms (such as Solaris), if you attach to a process
5254 without first loading a symbol file, GDB will now attempt to locate and
5255 load symbols from the running process's executable file.
5257 * Many C++ enhancements
5259 C++ support has been greatly improved. Overload resolution now works properly
5260 in almost all cases. RTTI support is on the way.
5262 * Remote targets can connect to a sub-program
5264 A popen(3) style serial-device has been added. This device starts a
5265 sub-process (such as a stand-alone simulator) and then communicates
5266 with that. The sub-program to run is specified using the syntax
5267 ``|<program> <args>'' vis:
5269 (gdb) set remotedebug 1
5270 (gdb) target extended-remote |mn10300-elf-sim program-args
5272 * MIPS 64 remote protocol
5274 A long standing bug in the mips64 remote protocol where by GDB
5275 expected certain 32 bit registers (ex SR) to be transfered as 32
5276 instead of 64 bits has been fixed.
5278 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5279 added to provide backward compatibility with older versions of GDB.
5281 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5283 The command ``set remotebinarydownload'' command has been replaced by
5284 ``set remote X-packet''. Other commands in ``set remote'' family
5285 include ``set remote P-packet''.
5287 * Breakpoint commands accept ranges.
5289 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5290 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5291 ``tracepoint passcount'' also accepts a range of tracepoints.
5293 * ``apropos'' command added.
5295 The ``apropos'' command searches through command names and
5296 documentation strings, printing out matches, making it much easier to
5297 try to find a command that does what you are looking for.
5301 A new machine oriented interface (MI) has been added to GDB. This
5302 interface is designed for debug environments running GDB as a separate
5303 process. This is part of the long term libGDB project. See the
5304 "GDB/MI" chapter of the GDB manual for further information. It can be
5305 enabled by configuring with:
5307 .../configure --enable-gdbmi
5309 *** Changes in GDB-4.18:
5311 * New native configurations
5313 HP-UX 10.20 hppa*-*-hpux10.20
5314 HP-UX 11.x hppa*-*-hpux11.0*
5315 M68K GNU/Linux m68*-*-linux*
5319 Fujitsu FR30 fr30-*-elf*
5320 Intel StrongARM strongarm-*-*
5321 Mitsubishi D30V d30v-*-*
5323 * OBSOLETE configurations
5325 Gould PowerNode, NP1 np1-*-*, pn-*-*
5327 Configurations that have been declared obsolete will be commented out,
5328 but the code will be left in place. If there is no activity to revive
5329 these configurations before the next release of GDB, the sources will
5330 be permanently REMOVED.
5334 As a compatibility experiment, GDB's source files buildsym.h and
5335 buildsym.c have been converted to pure standard C, no longer
5336 containing any K&R compatibility code. We believe that all systems in
5337 use today either come with a standard C compiler, or have a GCC port
5338 available. If this is not true, please report the affected
5339 configuration to bug-gdb@gnu.org immediately. See the README file for
5340 information about getting a standard C compiler if you don't have one
5345 GDB now uses readline 2.2.
5347 * set extension-language
5349 You can now control the mapping between filename extensions and source
5350 languages by using the `set extension-language' command. For instance,
5351 you can ask GDB to treat .c files as C++ by saying
5352 set extension-language .c c++
5353 The command `info extensions' lists all of the recognized extensions
5354 and their associated languages.
5356 * Setting processor type for PowerPC and RS/6000
5358 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5359 you can use the `set processor' command to specify what variant of the
5360 PowerPC family you are debugging. The command
5364 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5365 following PowerPC and RS6000 variants:
5367 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5368 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5370 403GC IBM PowerPC 403GC
5371 505 Motorola PowerPC 505
5372 860 Motorola PowerPC 860 or 850
5373 601 Motorola PowerPC 601
5374 602 Motorola PowerPC 602
5375 603 Motorola/IBM PowerPC 603 or 603e
5376 604 Motorola PowerPC 604 or 604e
5377 750 Motorola/IBM PowerPC 750 or 750
5379 At the moment, this command just tells GDB what to name the
5380 special-purpose processor registers. Since almost all the affected
5381 registers are inaccessible to user-level programs, this command is
5382 only useful for remote debugging in its present form.
5386 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5387 more extensive support for HP-UX. Added features include shared
5388 library support, kernel threads and hardware watchpoints for 11.00,
5389 support for HP's ANSI C and C++ compilers, and a compatibility mode
5390 for xdb and dbx commands.
5394 HP's donation includes the new concept of catchpoints, which is a
5395 generalization of the old catch command. On HP-UX, it is now possible
5396 to catch exec, fork, and vfork, as well as library loading.
5398 This means that the existing catch command has changed; its first
5399 argument now specifies the type of catch to be set up. See the
5400 output of "help catch" for a list of catchpoint types.
5402 * Debugging across forks
5404 On HP-UX, you can choose which process to debug when a fork() happens
5409 HP has donated a curses-based terminal user interface (TUI). To get
5410 it, build with --enable-tui. Although this can be enabled for any
5411 configuration, at present it only works for native HP debugging.
5413 * GDB remote protocol additions
5415 A new protocol packet 'X' that writes binary data is now available.
5416 Default behavior is to try 'X', then drop back to 'M' if the stub
5417 fails to respond. The settable variable `remotebinarydownload'
5418 allows explicit control over the use of 'X'.
5420 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5421 full 64-bit address. The command
5423 set remoteaddresssize 32
5425 can be used to revert to the old behaviour. For existing remote stubs
5426 the change should not be noticed, as the additional address information
5429 In order to assist in debugging stubs, you may use the maintenance
5430 command `packet' to send any text string to the stub. For instance,
5432 maint packet heythere
5434 sends the packet "$heythere#<checksum>". Note that it is very easy to
5435 disrupt a debugging session by sending the wrong packet at the wrong
5438 The compare-sections command allows you to compare section data on the
5439 target to what is in the executable file without uploading or
5440 downloading, by comparing CRC checksums.
5442 * Tracing can collect general expressions
5444 You may now collect general expressions at tracepoints. This requires
5445 further additions to the target-side stub; see tracepoint.c and
5446 doc/agentexpr.texi for further details.
5448 * mask-address variable for Mips
5450 For Mips targets, you may control the zeroing of the upper 32 bits of
5451 a 64-bit address by entering `set mask-address on'. This is mainly
5452 of interest to users of embedded R4xxx and R5xxx processors.
5454 * Higher serial baud rates
5456 GDB's serial code now allows you to specify baud rates 57600, 115200,
5457 230400, and 460800 baud. (Note that your host system may not be able
5458 to achieve all of these rates.)
5462 The i960 configuration now includes an initial implementation of a
5463 builtin simulator, contributed by Jim Wilson.
5466 *** Changes in GDB-4.17:
5468 * New native configurations
5470 Alpha GNU/Linux alpha*-*-linux*
5471 Unixware 2.x i[3456]86-unixware2*
5472 Irix 6.x mips*-sgi-irix6*
5473 PowerPC GNU/Linux powerpc-*-linux*
5474 PowerPC Solaris powerpcle-*-solaris*
5475 Sparc GNU/Linux sparc-*-linux*
5476 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5480 Argonaut Risc Chip (ARC) arc-*-*
5481 Hitachi H8/300S h8300*-*-*
5482 Matsushita MN10200 w/simulator mn10200-*-*
5483 Matsushita MN10300 w/simulator mn10300-*-*
5484 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5485 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5486 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5487 Mitsubishi D10V w/simulator d10v-*-*
5488 Mitsubishi M32R/D w/simulator m32r-*-elf*
5489 Tsqware Sparclet sparclet-*-*
5490 NEC V850 w/simulator v850-*-*
5492 * New debugging protocols
5494 ARM with RDI protocol arm*-*-*
5495 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5496 DDB and LSI variants of PMON protocol mips*-*-*
5497 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5498 PowerPC with SDS protocol powerpc{,le}-*-eabi
5499 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5503 All configurations can now understand and use the DWARF 2 debugging
5504 format. The choice is automatic, if the symbol file contains DWARF 2
5509 GDB now includes basic Java language support. This support is
5510 only useful with Java compilers that produce native machine code.
5512 * solib-absolute-prefix and solib-search-path
5514 For SunOS and SVR4 shared libraries, you may now set the prefix for
5515 loading absolute shared library symbol files, and the search path for
5516 locating non-absolute shared library symbol files.
5518 * Live range splitting
5520 GDB can now effectively debug code for which GCC has performed live
5521 range splitting as part of its optimization. See gdb/doc/LRS for
5522 more details on the expected format of the stabs information.
5526 GDB's support for the GNU Hurd, including thread debugging, has been
5527 updated to work with current versions of the Hurd.
5531 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5532 instruction set. ARM GDB automatically detects when Thumb
5533 instructions are in use, and adjusts disassembly and backtracing
5538 GDB's MIPS target configurations now handle the MIP16 16-bit
5543 GDB now includes support for overlays; if an executable has been
5544 linked such that multiple sections are based at the same address, GDB
5545 will decide which section to use for symbolic info. You can choose to
5546 control the decision manually, using overlay commands, or implement
5547 additional target-side support and use "overlay load-target" to bring
5548 in the overlay mapping. Do "help overlay" for more detail.
5552 The command "info symbol <address>" displays information about
5553 the symbol at the specified address.
5557 The standard remote protocol now includes an extension that allows
5558 asynchronous collection and display of trace data. This requires
5559 extensive support in the target-side debugging stub. Tracing mode
5560 includes a new interaction mode in GDB and new commands: see the
5561 file tracepoint.c for more details.
5565 Configurations for embedded MIPS now include a simulator contributed
5566 by Cygnus Solutions. The simulator supports the instruction sets
5567 of most MIPS variants.
5571 Sparc configurations may now include the ERC32 simulator contributed
5572 by the European Space Agency. The simulator is not built into
5573 Sparc targets by default; configure with --enable-sim to include it.
5577 For target configurations that may include multiple variants of a
5578 basic architecture (such as MIPS and SH), you may now set the
5579 architecture explicitly. "set arch" sets, "info arch" lists
5580 the possible architectures.
5582 *** Changes in GDB-4.16:
5584 * New native configurations
5586 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5587 M68K NetBSD m68k-*-netbsd*
5588 PowerPC AIX 4.x powerpc-*-aix*
5589 PowerPC MacOS powerpc-*-macos*
5590 PowerPC Windows NT powerpcle-*-cygwin32
5591 RS/6000 AIX 4.x rs6000-*-aix4*
5595 ARM with RDP protocol arm-*-*
5596 I960 with MON960 i960-*-coff
5597 MIPS VxWorks mips*-*-vxworks*
5598 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5599 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5601 Matra Sparclet sparclet-*-*
5605 The powerpc-eabi configuration now includes the PSIM simulator,
5606 contributed by Andrew Cagney, with assistance from Mike Meissner.
5607 PSIM is a very elaborate model of the PowerPC, including not only
5608 basic instruction set execution, but also details of execution unit
5609 performance and I/O hardware. See sim/ppc/README for more details.
5613 GDB now works with Solaris 2.5.
5615 * Windows 95/NT native
5617 GDB will now work as a native debugger on Windows 95 and Windows NT.
5618 To build it from source, you must use the "gnu-win32" environment,
5619 which uses a DLL to emulate enough of Unix to run the GNU tools.
5620 Further information, binaries, and sources are available at
5621 ftp.cygnus.com, under pub/gnu-win32.
5623 * dont-repeat command
5625 If a user-defined command includes the command `dont-repeat', then the
5626 command will not be repeated if the user just types return. This is
5627 useful if the command is time-consuming to run, so that accidental
5628 extra keystrokes don't run the same command many times.
5630 * Send break instead of ^C
5632 The standard remote protocol now includes an option to send a break
5633 rather than a ^C to the target in order to interrupt it. By default,
5634 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5636 * Remote protocol timeout
5638 The standard remote protocol includes a new variable `remotetimeout'
5639 that allows you to set the number of seconds before GDB gives up trying
5640 to read from the target. The default value is 2.
5642 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5644 By default GDB will automatically keep track of objects as they are
5645 loaded and unloaded by the dynamic linker. By using the command `set
5646 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5647 when shared library events occur, thus allowing you to set breakpoints
5648 in shared libraries which are explicitly loaded by the inferior.
5650 Note this feature does not work on hpux8. On hpux9 you must link
5651 /usr/lib/end.o into your program. This feature should work
5652 automatically on hpux10.
5654 * Irix 5.x hardware watchpoint support
5656 Irix 5 configurations now support the use of hardware watchpoints.
5658 * Mips protocol "SYN garbage limit"
5660 When debugging a Mips target using the `target mips' protocol, you
5661 may set the number of characters that GDB will ignore by setting
5662 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5663 every character. The default value is 1050.
5665 * Recording and replaying remote debug sessions
5667 If you set `remotelogfile' to the name of a file, gdb will write to it
5668 a recording of a remote debug session. This recording may then be
5669 replayed back to gdb using "gdbreplay". See gdbserver/README for
5670 details. This is useful when you have a problem with GDB while doing
5671 remote debugging; you can make a recording of the session and send it
5672 to someone else, who can then recreate the problem.
5674 * Speedups for remote debugging
5676 GDB includes speedups for downloading and stepping MIPS systems using
5677 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5678 and more efficient S-record downloading.
5680 * Memory use reductions and statistics collection
5682 GDB now uses less memory and reports statistics about memory usage.
5683 Try the `maint print statistics' command, for example.
5685 *** Changes in GDB-4.15:
5687 * Psymtabs for XCOFF
5689 The symbol reader for AIX GDB now uses partial symbol tables. This
5690 can greatly improve startup time, especially for large executables.
5692 * Remote targets use caching
5694 Remote targets now use a data cache to speed up communication with the
5695 remote side. The data cache could lead to incorrect results because
5696 it doesn't know about volatile variables, thus making it impossible to
5697 debug targets which use memory mapped I/O devices. `set remotecache
5698 off' turns the the data cache off.
5700 * Remote targets may have threads
5702 The standard remote protocol now includes support for multiple threads
5703 in the target system, using new protocol commands 'H' and 'T'. See
5704 gdb/remote.c for details.
5708 If GDB is configured with `--enable-netrom', then it will include
5709 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5710 acts as though it is a bank of ROM on the target board, but you can
5711 write into it over the network. GDB's support consists only of
5712 support for fast loading into the emulated ROM; to debug, you must use
5713 another protocol, such as standard remote protocol. The usual
5714 sequence is something like
5716 target nrom <netrom-hostname>
5718 target remote <netrom-hostname>:1235
5722 GDB now includes support for the Apple Macintosh, as a host only. It
5723 may be run as either an MPW tool or as a standalone application, and
5724 it can debug through the serial port. All the usual GDB commands are
5725 available, but to the target command, you must supply "serial" as the
5726 device type instead of "/dev/ttyXX". See mpw-README in the main
5727 directory for more information on how to build. The MPW configuration
5728 scripts */mpw-config.in support only a few targets, and only the
5729 mips-idt-ecoff target has been tested.
5733 GDB configuration now uses autoconf. This is not user-visible,
5734 but does simplify configuration and building.
5738 GDB now supports hpux10.
5740 *** Changes in GDB-4.14:
5742 * New native configurations
5744 x86 FreeBSD i[345]86-*-freebsd
5745 x86 NetBSD i[345]86-*-netbsd
5746 NS32k NetBSD ns32k-*-netbsd
5747 Sparc NetBSD sparc-*-netbsd
5751 A29K VxWorks a29k-*-vxworks
5752 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5753 CPU32 EST-300 emulator m68*-*-est*
5754 PowerPC ELF powerpc-*-elf
5757 * Alpha OSF/1 support for procfs
5759 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5760 possible to attach to running processes. As the mounting of the /proc
5761 filesystem is optional on the Alpha, GDB automatically determines
5762 the availability of /proc during startup. This can lead to problems
5763 if /proc is unmounted after GDB has been started.
5765 * Arguments to user-defined commands
5767 User commands may accept up to 10 arguments separated by whitespace.
5768 Arguments are accessed within the user command via $arg0..$arg9. A
5771 print $arg0 + $arg1 + $arg2
5773 To execute the command use:
5776 Defines the command "adder" which prints the sum of its three arguments.
5777 Note the arguments are text substitutions, so they may reference variables,
5778 use complex expressions, or even perform inferior function calls.
5780 * New `if' and `while' commands
5782 This makes it possible to write more sophisticated user-defined
5783 commands. Both commands take a single argument, which is the
5784 expression to evaluate, and must be followed by the commands to
5785 execute, one per line, if the expression is nonzero, the list being
5786 terminated by the word `end'. The `if' command list may include an
5787 `else' word, which causes the following commands to be executed only
5788 if the expression is zero.
5790 * Fortran source language mode
5792 GDB now includes partial support for Fortran 77. It will recognize
5793 Fortran programs and can evaluate a subset of Fortran expressions, but
5794 variables and functions may not be handled correctly. GDB will work
5795 with G77, but does not yet know much about symbols emitted by other
5798 * Better HPUX support
5800 Most debugging facilities now work on dynamic executables for HPPAs
5801 running hpux9 or later. You can attach to running dynamically linked
5802 processes, but by default the dynamic libraries will be read-only, so
5803 for instance you won't be able to put breakpoints in them. To change
5804 that behavior do the following before running the program:
5810 This will cause the libraries to be mapped private and read-write.
5811 To revert to the normal behavior, do this:
5817 You cannot set breakpoints or examine data in the library until after
5818 the library is loaded if the function/data symbols do not have
5821 GDB can now also read debug symbols produced by the HP C compiler on
5822 HPPAs (sorry, no C++, Fortran or 68k support).
5824 * Target byte order now dynamically selectable
5826 You can choose which byte order to use with a target system, via the
5827 commands "set endian big" and "set endian little", and you can see the
5828 current setting by using "show endian". You can also give the command
5829 "set endian auto", in which case GDB will use the byte order
5830 associated with the executable. Currently, only embedded MIPS
5831 configurations support dynamic selection of target byte order.
5833 * New DOS host serial code
5835 This version uses DPMI interrupts to handle buffered I/O, so you
5836 no longer need to run asynctsr when debugging boards connected to
5839 *** Changes in GDB-4.13:
5841 * New "complete" command
5843 This lists all the possible completions for the rest of the line, if it
5844 were to be given as a command itself. This is intended for use by emacs.
5846 * Trailing space optional in prompt
5848 "set prompt" no longer adds a space for you after the prompt you set. This
5849 allows you to set a prompt which ends in a space or one that does not.
5851 * Breakpoint hit counts
5853 "info break" now displays a count of the number of times the breakpoint
5854 has been hit. This is especially useful in conjunction with "ignore"; you
5855 can ignore a large number of breakpoint hits, look at the breakpoint info
5856 to see how many times the breakpoint was hit, then run again, ignoring one
5857 less than that number, and this will get you quickly to the last hit of
5860 * Ability to stop printing at NULL character
5862 "set print null-stop" will cause GDB to stop printing the characters of
5863 an array when the first NULL is encountered. This is useful when large
5864 arrays actually contain only short strings.
5866 * Shared library breakpoints
5868 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5869 breakpoints in shared libraries before the executable is run.
5871 * Hardware watchpoints
5873 There is a new hardware breakpoint for the watch command for sparclite
5874 targets. See gdb/sparclite/hw_breakpoint.note.
5876 Hardware watchpoints are also now supported under GNU/Linux.
5880 Annotations have been added. These are for use with graphical interfaces,
5881 and are still experimental. Currently only gdba.el uses these.
5883 * Improved Irix 5 support
5885 GDB now works properly with Irix 5.2.
5887 * Improved HPPA support
5889 GDB now works properly with the latest GCC and GAS.
5891 * New native configurations
5893 Sequent PTX4 i[34]86-sequent-ptx4
5894 HPPA running OSF/1 hppa*-*-osf*
5895 Atari TT running SVR4 m68*-*-sysv4*
5896 RS/6000 LynxOS rs6000-*-lynxos*
5900 OS/9000 i[34]86-*-os9k
5901 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5904 * Hitachi SH7000 and E7000-PC ICE support
5906 There is now support for communicating with the Hitachi E7000-PC ICE.
5907 This is available automatically when GDB is configured for the SH.
5911 As usual, a variety of small fixes and improvements, both generic
5912 and configuration-specific. See the ChangeLog for more detail.
5914 *** Changes in GDB-4.12:
5916 * Irix 5 is now supported
5920 GDB-4.12 on the HPPA has a number of changes which make it unable
5921 to debug the output from the currently released versions of GCC and
5922 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5923 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5924 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5927 *** Changes in GDB-4.11:
5929 * User visible changes:
5933 The "set remotedebug" option is now consistent between the mips remote
5934 target, remote targets using the gdb-specific protocol, UDI (AMD's
5935 debug protocol for the 29k) and the 88k bug monitor. It is now an
5936 integer specifying a debug level (normally 0 or 1, but 2 means more
5937 debugging info for the mips target).
5939 * DEC Alpha native support
5941 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5942 debug info, but GDB works fairly well with the DEC compiler and should
5943 work with a future GCC release. See the README file for a few
5944 Alpha-specific notes.
5946 * Preliminary thread implementation
5948 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5950 * LynxOS native and target support for 386
5952 This release has been hosted on LynxOS 2.2, and also can be configured
5953 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5956 * Improvements in C++ mangling/demangling.
5958 This release has much better g++ debugging, specifically in name
5959 mangling/demangling, virtual function calls, print virtual table,
5960 call methods, ...etc.
5962 *** Changes in GDB-4.10:
5964 * User visible changes:
5966 Remote debugging using the GDB-specific (`target remote') protocol now
5967 supports the `load' command. This is only useful if you have some
5968 other way of getting the stub to the target system, and you can put it
5969 somewhere in memory where it won't get clobbered by the download.
5971 Filename completion now works.
5973 When run under emacs mode, the "info line" command now causes the
5974 arrow to point to the line specified. Also, "info line" prints
5975 addresses in symbolic form (as well as hex).
5977 All vxworks based targets now support a user settable option, called
5978 vxworks-timeout. This option represents the number of seconds gdb
5979 should wait for responses to rpc's. You might want to use this if
5980 your vxworks target is, perhaps, a slow software simulator or happens
5981 to be on the far side of a thin network line.
5985 This release contains support for using a DEC alpha as a GDB host for
5986 cross debugging. Native alpha debugging is not supported yet.
5989 *** Changes in GDB-4.9:
5993 This is the first GDB release which is accompanied by a matching testsuite.
5994 The testsuite requires installation of dejagnu, which should be available
5995 via ftp from most sites that carry GNU software.
5999 'Cfront' style demangling has had its name changed to 'ARM' style, to
6000 emphasize that it was written from the specifications in the C++ Annotated
6001 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6002 disclaimers, it still generated too much confusion with users attempting to
6003 use gdb with AT&T cfront.
6007 GDB now uses a standard remote interface to a simulator library.
6008 So far, the library contains simulators for the Zilog Z8001/2, the
6009 Hitachi H8/300, H8/500 and Super-H.
6011 * New targets supported
6013 H8/300 simulator h8300-hitachi-hms or h8300hms
6014 H8/500 simulator h8500-hitachi-hms or h8500hms
6015 SH simulator sh-hitachi-hms or sh
6016 Z8000 simulator z8k-zilog-none or z8ksim
6017 IDT MIPS board over serial line mips-idt-ecoff
6019 Cross-debugging to GO32 targets is supported. It requires a custom
6020 version of the i386-stub.c module which is integrated with the
6021 GO32 memory extender.
6023 * New remote protocols
6025 MIPS remote debugging protocol.
6027 * New source languages supported
6029 This version includes preliminary support for Chill, a Pascal like language
6030 used by telecommunications companies. Chill support is also being integrated
6031 into the GNU compiler, but we don't know when it will be publically available.
6034 *** Changes in GDB-4.8:
6036 * HP Precision Architecture supported
6038 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6039 version of this support was available as a set of patches from the
6040 University of Utah. GDB does not support debugging of programs
6041 compiled with the HP compiler, because HP will not document their file
6042 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6043 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6045 Many problems in the preliminary version have been fixed.
6047 * Faster and better demangling
6049 We have improved template demangling and fixed numerous bugs in the GNU style
6050 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6051 character types (wchar_t) are now supported. Demangling of each symbol is now
6052 only done once, and is cached when the symbol table for a file is read in.
6053 This results in a small increase in memory usage for C programs, a moderate
6054 increase in memory usage for C++ programs, and a fantastic speedup in
6057 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6058 from the specifications in the Annotated Reference Manual, which AT&T's
6059 compiler does not actually implement.
6061 * G++ multiple inheritance compiler problem
6063 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6064 inheritance lattices was reworked to properly discover ambiguities. We
6065 recently found an example which causes this new algorithm to fail in a
6066 very subtle way, producing bad debug information for those classes.
6067 The file 'gcc.patch' (in this directory) can be applied to gcc to
6068 circumvent the problem. A future GCC release will contain a complete
6071 The previous G++ debug info problem (mentioned below for the gdb-4.7
6072 release) is fixed in gcc version 2.3.2.
6074 * Improved configure script
6076 The `configure' script will now attempt to guess your system type if
6077 you don't supply a host system type. The old scheme of supplying a
6078 host system triplet is preferable over using this. All the magic is
6079 done in the new `config.guess' script. Examine it for details.
6081 We have also brought our configure script much more in line with the FSF's
6082 version. It now supports the --with-xxx options. In particular,
6083 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6084 The resulting GDB will not be able to read arbitrary object file formats --
6085 only the format ``expected'' to be used on the configured target system.
6086 We hope to make this the default in a future release.
6088 * Documentation improvements
6090 There's new internal documentation on how to modify GDB, and how to
6091 produce clean changes to the code. We implore people to read it
6092 before submitting changes.
6094 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6095 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6096 `info' files are also provided. To build `info' files from scratch,
6097 you will need the latest `makeinfo' release, which will be available in
6098 a future texinfo-X.Y release.
6100 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6101 We're not sure exactly which versions have this problem, but it has
6102 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6103 or better. If that isn't possible, there is a patch in
6104 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6105 around this problem.
6109 GDB now supports array constants that can be used in expressions typed in by
6110 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6111 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6114 The new directory `gdb/sparclite' contains a program that demonstrates
6115 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6117 * New native hosts supported
6119 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6120 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6122 * New targets supported
6124 AMD 29k family via UDI a29k-amd-udi or udi29k
6126 * New file formats supported
6128 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6129 HPUX core files, and SCO 3.2v2 core files.
6133 Attaching to processes now works again; thanks for the many bug reports.
6135 We have also stomped on a bunch of core dumps caused by
6136 printf_filtered("%s") problems.
6138 We eliminated a copyright problem on the rpc and ptrace header files
6139 for VxWorks, which was discovered at the last minute during the 4.7
6140 release. You should now be able to build a VxWorks GDB.
6142 You can now interrupt gdb while an attached process is running. This
6143 will cause the attached process to stop, and give control back to GDB.
6145 We fixed problems caused by using too many file descriptors
6146 for reading symbols from object files and libraries. This was
6147 especially a problem for programs that used many (~100) shared
6150 The `step' command now only enters a subroutine if there is line number
6151 information for the subroutine. Otherwise it acts like the `next'
6152 command. Previously, `step' would enter subroutines if there was
6153 any debugging information about the routine. This avoids problems
6154 when using `cc -g1' on MIPS machines.
6156 * Internal improvements
6158 GDB's internal interfaces have been improved to make it easier to support
6159 debugging of multiple languages in the future.
6161 GDB now uses a common structure for symbol information internally.
6162 Minimal symbols (derived from linkage symbols in object files), partial
6163 symbols (from a quick scan of debug information), and full symbols
6164 contain a common subset of information, making it easier to write
6165 shared code that handles any of them.
6167 * New command line options
6169 We now accept --silent as an alias for --quiet.
6173 The memory-mapped-malloc library is now licensed under the GNU Library
6174 General Public License.
6176 *** Changes in GDB-4.7:
6178 * Host/native/target split
6180 GDB has had some major internal surgery to untangle the support for
6181 hosts and remote targets. Now, when you configure GDB for a remote
6182 target, it will no longer load in all of the support for debugging
6183 local programs on the host. When fully completed and tested, this will
6184 ensure that arbitrary host/target combinations are possible.
6186 The primary conceptual shift is to separate the non-portable code in
6187 GDB into three categories. Host specific code is required any time GDB
6188 is compiled on that host, regardless of the target. Target specific
6189 code relates to the peculiarities of the target, but can be compiled on
6190 any host. Native specific code is everything else: it can only be
6191 built when the host and target are the same system. Child process
6192 handling and core file support are two common `native' examples.
6194 GDB's use of /proc for controlling Unix child processes is now cleaner.
6195 It has been split out into a single module under the `target_ops' vector,
6196 plus two native-dependent functions for each system that uses /proc.
6198 * New hosts supported
6200 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6201 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6202 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6204 * New targets supported
6206 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6207 68030 and CPU32 m68030-*-*, m68332-*-*
6209 * New native hosts supported
6211 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6212 (386bsd is not well tested yet)
6213 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6215 * New file formats supported
6217 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6218 supports reading of `a.out.adobe' object files, which are an a.out
6219 format extended with minimal information about multiple sections.
6223 `show copying' is the same as the old `info copying'.
6224 `show warranty' is the same as `info warrantee'.
6225 These were renamed for consistency. The old commands continue to work.
6227 `info handle' is a new alias for `info signals'.
6229 You can now define pre-command hooks, which attach arbitrary command
6230 scripts to any command. The commands in the hook will be executed
6231 prior to the user's command. You can also create a hook which will be
6232 executed whenever the program stops. See gdb.texinfo.
6236 We now deal with Cfront style name mangling, and can even extract type
6237 info from mangled symbols. GDB can automatically figure out which
6238 symbol mangling style your C++ compiler uses.
6240 Calling of methods and virtual functions has been improved as well.
6244 The crash that occured when debugging Sun Ansi-C compiled binaries is
6245 fixed. This was due to mishandling of the extra N_SO stabs output
6248 We also finally got Ultrix 4.2 running in house, and fixed core file
6249 support, with help from a dozen people on the net.
6251 John M. Farrell discovered that the reason that single-stepping was so
6252 slow on all of the Mips based platforms (primarily SGI and DEC) was
6253 that we were trying to demangle and lookup a symbol used for internal
6254 purposes on every instruction that was being stepped through. Changing
6255 the name of that symbol so that it couldn't be mistaken for a C++
6256 mangled symbol sped things up a great deal.
6258 Rich Pixley sped up symbol lookups in general by getting much smarter
6259 about when C++ symbol mangling is necessary. This should make symbol
6260 completion (TAB on the command line) much faster. It's not as fast as
6261 we'd like, but it's significantly faster than gdb-4.6.
6265 A new user controllable variable 'call_scratch_address' can
6266 specify the location of a scratch area to be used when GDB
6267 calls a function in the target. This is necessary because the
6268 usual method of putting the scratch area on the stack does not work
6269 in systems that have separate instruction and data spaces.
6271 We integrated changes to support the 29k UDI (Universal Debugger
6272 Interface), but discovered at the last minute that we didn't have all
6273 of the appropriate copyright paperwork. We are working with AMD to
6274 resolve this, and hope to have it available soon.
6278 We have sped up the remote serial line protocol, especially for targets
6279 with lots of registers. It now supports a new `expedited status' ('T')
6280 message which can be used in place of the existing 'S' status message.
6281 This allows the remote stub to send only the registers that GDB
6282 needs to make a quick decision about single-stepping or conditional
6283 breakpoints, eliminating the need to fetch the entire register set for
6284 each instruction being stepped through.
6286 The GDB remote serial protocol now implements a write-through cache for
6287 registers, only re-reading the registers if the target has run.
6289 There is also a new remote serial stub for SPARC processors. You can
6290 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6291 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6292 processor with a serial port.
6296 Configure.in files have become much easier to read and modify. A new
6297 `table driven' format makes it more obvious what configurations are
6298 supported, and what files each one uses.
6302 There is a new opcodes library which will eventually contain all of the
6303 disassembly routines and opcode tables. At present, it only contains
6304 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6305 disassembler (binutils/objdump) to share these routines.
6307 The libiberty library is now copylefted under the GNU Library General
6308 Public License. This allows more liberal use, and was done so libg++
6309 can use it. This makes no difference to GDB, since the Library License
6310 grants all the rights from the General Public License.
6314 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6315 reference to the stabs symbol info used by the debugger. It is (as far
6316 as we know) the only published document on this fascinating topic. We
6317 encourage you to read it, compare it to the stabs information on your
6318 system, and send improvements on the document in general (to
6319 bug-gdb@prep.ai.mit.edu).
6321 And, of course, many bugs have been fixed.
6324 *** Changes in GDB-4.6:
6326 * Better support for C++ function names
6328 GDB now accepts as input the "demangled form" of C++ overloaded function
6329 names and member function names, and can do command completion on such names
6330 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6331 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6332 Make use of command completion, it is your friend.
6334 GDB also now accepts a variety of C++ mangled symbol formats. They are
6335 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6336 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6337 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6338 for the list of formats.
6340 * G++ symbol mangling problem
6342 Recent versions of gcc have a bug in how they emit debugging information for
6343 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6344 directory) can be applied to gcc to fix the problem. Alternatively, if you
6345 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6346 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6347 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6350 * New 'maintenance' command
6352 All of the commands related to hacking GDB internals have been moved out of
6353 the main command set, and now live behind the 'maintenance' command. This
6354 can also be abbreviated as 'mt'. The following changes were made:
6356 dump-me -> maintenance dump-me
6357 info all-breakpoints -> maintenance info breakpoints
6358 printmsyms -> maintenance print msyms
6359 printobjfiles -> maintenance print objfiles
6360 printpsyms -> maintenance print psymbols
6361 printsyms -> maintenance print symbols
6363 The following commands are new:
6365 maintenance demangle Call internal GDB demangler routine to
6366 demangle a C++ link name and prints the result.
6367 maintenance print type Print a type chain for a given symbol
6369 * Change to .gdbinit file processing
6371 We now read the $HOME/.gdbinit file before processing the argv arguments
6372 (e.g. reading symbol files or core files). This allows global parameters to
6373 be set, which will apply during the symbol reading. The ./.gdbinit is still
6374 read after argv processing.
6376 * New hosts supported
6378 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6380 GNU/Linux support i386-unknown-linux or linux
6382 We are also including code to support the HP/PA running BSD and HPUX. This
6383 is almost guaranteed not to work, as we didn't have time to test or build it
6384 for this release. We are including it so that the more adventurous (or
6385 masochistic) of you can play with it. We also had major problems with the
6386 fact that the compiler that we got from HP doesn't support the -g option.
6389 * New targets supported
6391 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6393 * More smarts about finding #include files
6395 GDB now remembers the compilation directory for all include files, and for
6396 all files from which C is generated (like yacc and lex sources). This
6397 greatly improves GDB's ability to find yacc/lex sources, and include files,
6398 especially if you are debugging your program from a directory different from
6399 the one that contains your sources.
6401 We also fixed a bug which caused difficulty with listing and setting
6402 breakpoints in include files which contain C code. (In the past, you had to
6403 try twice in order to list an include file that you hadn't looked at before.)
6405 * Interesting infernals change
6407 GDB now deals with arbitrary numbers of sections, where the symbols for each
6408 section must be relocated relative to that section's landing place in the
6409 target's address space. This work was needed to support ELF with embedded
6410 stabs used by Solaris-2.0.
6412 * Bug fixes (of course!)
6414 There have been loads of fixes for the following things:
6415 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6416 i960, stabs, DOS(GO32), procfs, etc...
6418 See the ChangeLog for details.
6420 *** Changes in GDB-4.5:
6422 * New machines supported (host and target)
6424 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6426 SGI Irix-4.x mips-sgi-irix4 or iris4
6428 * New malloc package
6430 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6431 Mmalloc is capable of handling mutiple heaps of memory. It is also
6432 capable of saving a heap to a file, and then mapping it back in later.
6433 This can be used to greatly speedup the startup of GDB by using a
6434 pre-parsed symbol table which lives in a mmalloc managed heap. For
6435 more details, please read mmalloc/mmalloc.texi.
6439 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6440 'help info proc' for details.
6442 * MIPS ecoff symbol table format
6444 The code that reads MIPS symbol table format is now supported on all hosts.
6445 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6448 * File name changes for MS-DOS
6450 Many files in the config directories have been renamed to make it easier to
6451 support GDB on MS-DOSe systems (which have very restrictive file name
6452 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6453 environment) is close to working but has some remaining problems. Note
6454 that debugging of DOS programs is not supported, due to limitations
6455 in the ``operating system'', but it can be used to host cross-debugging.
6457 * Cross byte order fixes
6459 Many fixes have been made to support cross debugging of Sparc and MIPS
6460 targets from hosts whose byte order differs.
6462 * New -mapped and -readnow options
6464 If memory-mapped files are available on your system through the 'mmap'
6465 system call, you can use the -mapped option on the `file' or
6466 `symbol-file' commands to cause GDB to write the symbols from your
6467 program into a reusable file. If the program you are debugging is
6468 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6469 Future GDB debugging sessions will notice the presence of this file,
6470 and will quickly map in symbol information from it, rather than reading
6471 the symbol table from the executable program. Using the '-mapped'
6472 option in a GDB `file' or `symbol-file' command has the same effect as
6473 starting GDB with the '-mapped' command-line option.
6475 You can cause GDB to read the entire symbol table immediately by using
6476 the '-readnow' option with any of the commands that load symbol table
6477 information (or on the GDB command line). This makes the command
6478 slower, but makes future operations faster.
6480 The -mapped and -readnow options are typically combined in order to
6481 build a `fred.syms' file that contains complete symbol information.
6482 A simple GDB invocation to do nothing but build a `.syms' file for future
6485 gdb -batch -nx -mapped -readnow programname
6487 The `.syms' file is specific to the host machine on which GDB is run.
6488 It holds an exact image of GDB's internal symbol table. It cannot be
6489 shared across multiple host platforms.
6491 * longjmp() handling
6493 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6494 siglongjmp() without losing control. This feature has not yet been ported to
6495 all systems. It currently works on many 386 platforms, all MIPS-based
6496 platforms (SGI, DECstation, etc), and Sun3/4.
6500 Preliminary work has been put in to support the new Solaris OS from Sun. At
6501 this time, it can control and debug processes, but it is not capable of
6506 As always, many many bug fixes. The major areas were with g++, and mipsread.
6507 People using the MIPS-based platforms should experience fewer mysterious
6508 crashes and trashed symbol tables.
6510 *** Changes in GDB-4.4:
6512 * New machines supported (host and target)
6514 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6516 BSD Reno on Vax vax-dec-bsd
6517 Ultrix on Vax vax-dec-ultrix
6519 * New machines supported (target)
6521 AMD 29000 embedded, using EBMON a29k-none-none
6525 GDB continues to improve its handling of C++. `References' work better.
6526 The demangler has also been improved, and now deals with symbols mangled as
6527 per the Annotated C++ Reference Guide.
6529 GDB also now handles `stabs' symbol information embedded in MIPS
6530 `ecoff' symbol tables. Since the ecoff format was not easily
6531 extensible to handle new languages such as C++, this appeared to be a
6532 good way to put C++ debugging info into MIPS binaries. This option
6533 will be supported in the GNU C compiler, version 2, when it is
6536 * New features for SVR4
6538 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6539 shared libraries. Debugging dynamically linked programs should present
6540 only minor differences from debugging statically linked programs.
6542 The `info proc' command will print out information about any process
6543 on an SVR4 system (including the one you are debugging). At the moment,
6544 it prints the address mappings of the process.
6546 If you bring up GDB on another SVR4 system, please send mail to
6547 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6549 * Better dynamic linking support in SunOS
6551 Reading symbols from shared libraries which contain debugging symbols
6552 now works properly. However, there remain issues such as automatic
6553 skipping of `transfer vector' code during function calls, which
6554 make it harder to debug code in a shared library, than to debug the
6555 same code linked statically.
6559 GDB is now using the latest `getopt' routines from the FSF. This
6560 version accepts the -- prefix for options with long names. GDB will
6561 continue to accept the old forms (-option and +option) as well.
6562 Various single letter abbreviations for options have been explicity
6563 added to the option table so that they won't get overshadowed in the
6564 future by other options that begin with the same letter.
6568 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6569 Many assorted bugs have been handled. Many more remain to be handled.
6570 See the various ChangeLog files (primarily in gdb and bfd) for details.
6573 *** Changes in GDB-4.3:
6575 * New machines supported (host and target)
6577 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6578 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6579 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6581 * Almost SCO Unix support
6583 We had hoped to support:
6584 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6585 (except for core file support), but we discovered very late in the release
6586 that it has problems with process groups that render gdb unusable. Sorry
6587 about that. I encourage people to fix it and post the fixes.
6589 * Preliminary ELF and DWARF support
6591 GDB can read ELF object files on System V Release 4, and can handle
6592 debugging records for C, in DWARF format, in ELF files. This support
6593 is preliminary. If you bring up GDB on another SVR4 system, please
6594 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6599 GDB now uses the latest `readline' library. One user-visible change
6600 is that two tabs will list possible command completions, which previously
6601 required typing M-? (meta-question mark, or ESC ?).
6605 The `stepi' bug that many of you noticed has been squashed.
6606 Many bugs in C++ have been handled. Many more remain to be handled.
6607 See the various ChangeLog files (primarily in gdb and bfd) for details.
6609 * State of the MIPS world (in case you wondered):
6611 GDB can understand the symbol tables emitted by the compilers
6612 supplied by most vendors of MIPS-based machines, including DEC. These
6613 symbol tables are in a format that essentially nobody else uses.
6615 Some versions of gcc come with an assembler post-processor called
6616 mips-tfile. This program is required if you want to do source-level
6617 debugging of gcc-compiled programs. I believe FSF does not ship
6618 mips-tfile with gcc version 1, but it will eventually come with gcc
6621 Debugging of g++ output remains a problem. g++ version 1.xx does not
6622 really support it at all. (If you're lucky, you should be able to get
6623 line numbers and stack traces to work, but no parameters or local
6624 variables.) With some work it should be possible to improve the
6627 When gcc version 2 is released, you will have somewhat better luck.
6628 However, even then you will get confusing results for inheritance and
6631 We will eventually provide full debugging of g++ output on
6632 DECstations. This will probably involve some kind of stabs-in-ecoff
6633 encapulation, but the details have not been worked out yet.
6636 *** Changes in GDB-4.2:
6638 * Improved configuration
6640 Only one copy of `configure' exists now, and it is not self-modifying.
6641 Porting BFD is simpler.
6645 The `step' and `next' commands now only stop at the first instruction
6646 of a source line. This prevents the multiple stops that used to occur
6647 in switch statements, for-loops, etc. `Step' continues to stop if a
6648 function that has debugging information is called within the line.
6652 Lots of small bugs fixed. More remain.
6654 * New host supported (not target)
6656 Intel 386 PC clone running Mach i386-none-mach
6659 *** Changes in GDB-4.1:
6661 * Multiple source language support
6663 GDB now has internal scaffolding to handle several source languages.
6664 It determines the type of each source file from its filename extension,
6665 and will switch expression parsing and number formatting to match the
6666 language of the function in the currently selected stack frame.
6667 You can also specifically set the language to be used, with
6668 `set language c' or `set language modula-2'.
6672 GDB now has preliminary support for the GNU Modula-2 compiler,
6673 currently under development at the State University of New York at
6674 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6675 continue through the fall of 1991 and into 1992.
6677 Other Modula-2 compilers are currently not supported, and attempting to
6678 debug programs compiled with them will likely result in an error as the
6679 symbol table is read. Feel free to work on it, though!
6681 There are hooks in GDB for strict type checking and range checking,
6682 in the `Modula-2 philosophy', but they do not currently work.
6686 GDB can now write to executable and core files (e.g. patch
6687 a variable's value). You must turn this switch on, specify
6688 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6689 by assigning a new value to a variable. Modifications take
6692 * Automatic SunOS shared library reading
6694 When you run your program, GDB automatically determines where its
6695 shared libraries (if any) have been loaded, and reads their symbols.
6696 The `share' command is no longer needed. This also works when
6697 examining core files.
6701 You can specify the number of lines that the `list' command shows.
6704 * New machines supported (host and target)
6706 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6707 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6708 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6710 * New hosts supported (not targets)
6712 IBM RT/PC: romp-ibm-aix or rtpc
6714 * New targets supported (not hosts)
6716 AMD 29000 embedded with COFF a29k-none-coff
6717 AMD 29000 embedded with a.out a29k-none-aout
6718 Ultracomputer remote kernel debug a29k-nyu-kern
6720 * New remote interfaces
6726 *** Changes in GDB-4.0:
6730 Wide output is wrapped at good places to make the output more readable.
6732 Gdb now supports cross-debugging from a host machine of one type to a
6733 target machine of another type. Communication with the target system
6734 is over serial lines. The ``target'' command handles connecting to the
6735 remote system; the ``load'' command will download a program into the
6736 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6737 also supports debugging of realtime processes running under VxWorks,
6738 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6739 stub on the target system.
6741 New CPUs supported include the AMD 29000 and Intel 960.
6743 GDB now reads object files and symbol tables via a ``binary file''
6744 library, which allows a single copy of GDB to debug programs of multiple
6745 object file types such as a.out and coff.
6747 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6748 refcard.dvi and refcard.ps are available to format it).
6751 * Control-Variable user interface simplified
6753 All variables that control the operation of the debugger can be set
6754 by the ``set'' command, and displayed by the ``show'' command.
6756 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6757 ``Show prompt'' produces the response:
6758 Gdb's prompt is new-gdb=>.
6760 What follows are the NEW set commands. The command ``help set'' will
6761 print a complete list of old and new set commands. ``help set FOO''
6762 will give a longer description of the variable FOO. ``show'' will show
6763 all of the variable descriptions and their current settings.
6765 confirm on/off: Enables warning questions for operations that are
6766 hard to recover from, e.g. rerunning the program while
6767 it is already running. Default is ON.
6769 editing on/off: Enables EMACS style command line editing
6770 of input. Previous lines can be recalled with
6771 control-P, the current line can be edited with control-B,
6772 you can search for commands with control-R, etc.
6775 history filename NAME: NAME is where the gdb command history
6776 will be stored. The default is .gdb_history,
6777 or the value of the environment variable
6780 history size N: The size, in commands, of the command history. The
6781 default is 256, or the value of the environment variable
6784 history save on/off: If this value is set to ON, the history file will
6785 be saved after exiting gdb. If set to OFF, the
6786 file will not be saved. The default is OFF.
6788 history expansion on/off: If this value is set to ON, then csh-like
6789 history expansion will be performed on
6790 command line input. The default is OFF.
6792 radix N: Sets the default radix for input and output. It can be set
6793 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6794 in the current radix, so "set radix 10" is always a no-op.
6796 height N: This integer value is the number of lines on a page. Default
6797 is 24, the current `stty rows'' setting, or the ``li#''
6798 setting from the termcap entry matching the environment
6801 width N: This integer value is the number of characters on a line.
6802 Default is 80, the current `stty cols'' setting, or the ``co#''
6803 setting from the termcap entry matching the environment
6806 Note: ``set screensize'' is obsolete. Use ``set height'' and
6807 ``set width'' instead.
6809 print address on/off: Print memory addresses in various command displays,
6810 such as stack traces and structure values. Gdb looks
6811 more ``symbolic'' if you turn this off; it looks more
6812 ``machine level'' with it on. Default is ON.
6814 print array on/off: Prettyprint arrays. New convenient format! Default
6817 print demangle on/off: Print C++ symbols in "source" form if on,
6820 print asm-demangle on/off: Same, for assembler level printouts
6823 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6826 * Support for Epoch Environment.
6828 The epoch environment is a version of Emacs v18 with windowing. One
6829 new command, ``inspect'', is identical to ``print'', except that if you
6830 are running in the epoch environment, the value is printed in its own
6834 * Support for Shared Libraries
6836 GDB can now debug programs and core files that use SunOS shared libraries.
6837 Symbols from a shared library cannot be referenced
6838 before the shared library has been linked with the program (this
6839 happens after you type ``run'' and before the function main() is entered).
6840 At any time after this linking (including when examining core files
6841 from dynamically linked programs), gdb reads the symbols from each
6842 shared library when you type the ``sharedlibrary'' command.
6843 It can be abbreviated ``share''.
6845 sharedlibrary REGEXP: Load shared object library symbols for files
6846 matching a unix regular expression. No argument
6847 indicates to load symbols for all shared libraries.
6849 info sharedlibrary: Status of loaded shared libraries.
6854 A watchpoint stops execution of a program whenever the value of an
6855 expression changes. Checking for this slows down execution
6856 tremendously whenever you are in the scope of the expression, but is
6857 quite useful for catching tough ``bit-spreader'' or pointer misuse
6858 problems. Some machines such as the 386 have hardware for doing this
6859 more quickly, and future versions of gdb will use this hardware.
6861 watch EXP: Set a watchpoint (breakpoint) for an expression.
6863 info watchpoints: Information about your watchpoints.
6865 delete N: Deletes watchpoint number N (same as breakpoints).
6866 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6867 enable N: Re-enables watchpoint number N (same as breakpoints).
6870 * C++ multiple inheritance
6872 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6875 * C++ exception handling
6877 Gdb now supports limited C++ exception handling. Besides the existing
6878 ability to breakpoint on an exception handler, gdb can breakpoint on
6879 the raising of an exception (before the stack is peeled back to the
6882 catch FOO: If there is a FOO exception handler in the dynamic scope,
6883 set a breakpoint to catch exceptions which may be raised there.
6884 Multiple exceptions (``catch foo bar baz'') may be caught.
6886 info catch: Lists all exceptions which may be caught in the
6887 current stack frame.
6890 * Minor command changes
6892 The command ``call func (arg, arg, ...)'' now acts like the print
6893 command, except it does not print or save a value if the function's result
6894 is void. This is similar to dbx usage.
6896 The ``up'' and ``down'' commands now always print the frame they end up
6897 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6898 frames without printing.
6900 * New directory command
6902 'dir' now adds directories to the FRONT of the source search path.
6903 The path starts off empty. Source files that contain debug information
6904 about the directory in which they were compiled can be found even
6905 with an empty path; Sun CC and GCC include this information. If GDB can't
6906 find your source file in the current directory, type "dir .".
6908 * Configuring GDB for compilation
6910 For normal use, type ``./configure host''. See README or gdb.texinfo
6913 GDB now handles cross debugging. If you are remotely debugging between
6914 two different machines, type ``./configure host -target=targ''.
6915 Host is the machine where GDB will run; targ is the machine
6916 where the program that you are debugging will run.