1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * 'info proc' now works on running processes on FreeBSD systems and core
7 files created on FreeBSD systems.
13 Control display of debugging info regarding the FreeBSD native target.
15 *** Changes in GDB 8.1
17 * GDB now supports dynamically creating arbitrary register groups specified
18 in XML target descriptions. This allows for finer grain grouping of
19 registers on systems with a large amount of registers.
21 * The 'ptype' command now accepts a '/o' flag, which prints the
22 offsets and sizes of fields in a struct, like the pahole(1) tool.
24 * New "--readnever" command line option instructs GDB to not read each
25 symbol file's symbolic debug information. This makes startup faster
26 but at the expense of not being able to perform symbolic debugging.
27 This option is intended for use cases where symbolic debugging will
28 not be used, e.g., when you only need to dump the debuggee's core.
30 * GDB now uses the GNU MPFR library, if available, to emulate target
31 floating-point arithmetic during expression evaluation when the target
32 uses different floating-point formats than the host. At least version
33 3.1 of GNU MPFR is required.
35 * GDB now supports access to the guarded-storage-control registers and the
36 software-based guarded-storage broadcast control registers on IBM z14.
38 * On Unix systems, GDB now supports transmitting environment variables
39 that are to be set or unset to GDBserver. These variables will
40 affect the environment to be passed to the remote inferior.
42 To inform GDB of environment variables that are to be transmitted to
43 GDBserver, use the "set environment" command. Only user set
44 environment variables are sent to GDBserver.
46 To inform GDB of environment variables that are to be unset before
47 the remote inferior is started by the GDBserver, use the "unset
50 * Completion improvements
52 ** GDB can now complete function parameters in linespecs and
53 explicit locations without quoting. When setting breakpoints,
54 quoting around functions names to help with TAB-completion is
55 generally no longer necessary. For example, this now completes
58 (gdb) b function(in[TAB]
61 Related, GDB is no longer confused with completing functions in
62 C++ anonymous namespaces:
65 (gdb) b (anonymous namespace)::[TAB][TAB]
66 (anonymous namespace)::a_function()
67 (anonymous namespace)::b_function()
69 ** GDB now has much improved linespec and explicit locations TAB
70 completion support, that better understands what you're
71 completing and offers better suggestions. For example, GDB no
72 longer offers data symbols as possible completions when you're
75 ** GDB now TAB-completes label symbol names.
77 ** The "complete" command now mimics TAB completion accurately.
79 * New command line options (gcore)
82 Dump all memory mappings.
84 * Breakpoints on C++ functions are now set on all scopes by default
86 By default, breakpoints on functions/methods are now interpreted as
87 specifying all functions with the given name ignoring missing
88 leading scopes (namespaces and classes).
90 For example, assuming a C++ program with symbols named:
95 both commands "break func()" and "break B::func()" set a breakpoint
98 You can use the new flag "-qualified" to override this. This makes
99 GDB interpret the specified function name as a complete
100 fully-qualified name instead. For example, using the same C++
101 program, the "break -q B::func" command sets a breakpoint on
102 "B::func", only. A parameter has been added to the Python
103 gdb.Breakpoint constructor to achieve the same result when creating
104 a breakpoint from Python.
106 * Breakpoints on functions marked with C++ ABI tags
108 GDB can now set breakpoints on functions marked with C++ ABI tags
109 (e.g., [abi:cxx11]). See here for a description of ABI tags:
110 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
112 Functions with a C++11 abi tag are demangled/displayed like this:
114 function[abi:cxx11](int)
117 You can now set a breakpoint on such functions simply as if they had
120 (gdb) b function(int)
122 Or if you need to disambiguate between tags, like:
124 (gdb) b function[abi:other_tag](int)
126 Tab completion was adjusted accordingly as well.
130 ** New events gdb.new_inferior, gdb.inferior_deleted, and
131 gdb.new_thread are emitted. See the manual for further
132 description of these.
134 ** A new function, "gdb.rbreak" has been added to the Python API.
135 This function allows the setting of a large number of breakpoints
136 via a regex pattern in Python. See the manual for further details.
138 ** Python breakpoints can now accept explicit locations. See the
139 manual for a further description of this feature.
142 * New features in the GDB remote stub, GDBserver
144 ** GDBserver is now able to start inferior processes with a
145 specified initial working directory.
147 The user can set the desired working directory to be used from
148 GDB using the new "set cwd" command.
150 ** New "--selftest" command line option runs some GDBserver self
151 tests. These self tests are disabled in releases.
153 ** On Unix systems, GDBserver now does globbing expansion and variable
154 substitution in inferior command line arguments.
156 This is done by starting inferiors using a shell, like GDB does.
157 See "set startup-with-shell" in the user manual for how to disable
158 this from GDB when using "target extended-remote". When using
159 "target remote", you can disable the startup with shell by using the
160 new "--no-startup-with-shell" GDBserver command line option.
162 ** On Unix systems, GDBserver now supports receiving environment
163 variables that are to be set or unset from GDB. These variables
164 will affect the environment to be passed to the inferior.
166 * When catching an Ada exception raised with a message, GDB now prints
167 the message in the catchpoint hit notification. In GDB/MI mode, that
168 information is provided as an extra field named "exception-message"
169 in the *stopped notification.
171 * Trait objects can now be inspected When debugging Rust code. This
172 requires compiler support which will appear in Rust 1.24.
176 QEnvironmentHexEncoded
177 Inform GDBserver of an environment variable that is to be passed to
178 the inferior when starting it.
181 Inform GDBserver of an environment variable that is to be unset
182 before starting the remote inferior.
185 Inform GDBserver that the environment should be reset (i.e.,
186 user-set environment variables should be unset).
189 Indicates whether the inferior must be started with a shell or not.
192 Tell GDBserver that the inferior to be started should use a specific
195 * The "maintenance print c-tdesc" command now takes an optional
196 argument which is the file name of XML target description.
198 * The "maintenance selftest" command now takes an optional argument to
199 filter the tests to be run.
201 * The "enable", and "disable" commands now accept a range of
202 breakpoint locations, e.g. "enable 1.3-5".
207 Set and show the current working directory for the inferior.
210 Set and show compilation command used for compiling and injecting code
211 with the 'compile' commands.
213 set debug separate-debug-file
214 show debug separate-debug-file
215 Control the display of debug output about separate debug file search.
217 set dump-excluded-mappings
218 show dump-excluded-mappings
219 Control whether mappings marked with the VM_DONTDUMP flag should be
220 dumped when generating a core file.
223 List the registered selftests.
226 Start the debugged program stopping at the first instruction.
229 Control display of debugging messages related to OpenRISC targets.
231 set|show print type nested-type-limit
232 Set and show the limit of nesting level for nested types that the
233 type printer will show.
235 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
238 * Safer/improved support for debugging with no debug info
240 GDB no longer assumes functions with no debug information return
243 This means that GDB now refuses to call such functions unless you
244 tell it the function's type, by either casting the call to the
245 declared return type, or by casting the function to a function
246 pointer of the right type, and calling that:
248 (gdb) p getenv ("PATH")
249 'getenv' has unknown return type; cast the call to its declared return type
250 (gdb) p (char *) getenv ("PATH")
251 $1 = 0x7fffffffe "/usr/local/bin:/"...
252 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
253 $2 = 0x7fffffffe "/usr/local/bin:/"...
255 Similarly, GDB no longer assumes that global variables with no debug
256 info have type 'int', and refuses to print the variable's value
257 unless you tell it the variable's type:
260 'var' has unknown type; cast it to its declared type
264 * New native configurations
266 FreeBSD/aarch64 aarch64*-*-freebsd*
267 FreeBSD/arm arm*-*-freebsd*
271 FreeBSD/aarch64 aarch64*-*-freebsd*
272 FreeBSD/arm arm*-*-freebsd*
273 OpenRISC ELF or1k*-*-elf
275 * Removed targets and native configurations
277 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
279 *** Changes in GDB 8.0
281 * GDB now supports access to the PKU register on GNU/Linux. The register is
282 added by the Memory Protection Keys for Userspace feature which will be
283 available in future Intel CPUs.
285 * GDB now supports C++11 rvalue references.
289 ** New functions to start, stop and access a running btrace recording.
290 ** Rvalue references are now supported in gdb.Type.
292 * GDB now supports recording and replaying rdrand and rdseed Intel 64
295 * Building GDB and GDBserver now requires a C++11 compiler.
297 For example, GCC 4.8 or later.
299 It is no longer possible to build GDB or GDBserver with a C
300 compiler. The --disable-build-with-cxx configure option has been
303 * Building GDB and GDBserver now requires GNU make >= 3.81.
305 It is no longer supported to build GDB or GDBserver with another
306 implementation of the make program or an earlier version of GNU make.
308 * Native debugging on MS-Windows supports command-line redirection
310 Command-line arguments used for starting programs on MS-Windows can
311 now include redirection symbols supported by native Windows shells,
312 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
313 as "run", "start", and "set args", as well as the corresponding MI
316 * Support for thread names on MS-Windows.
318 GDB now catches and handles the special exception that programs
319 running on MS-Windows use to assign names to threads in the
322 * Support for Java programs compiled with gcj has been removed.
324 * User commands now accept an unlimited number of arguments.
325 Previously, only up to 10 was accepted.
327 * The "eval" command now expands user-defined command arguments.
329 This makes it easier to process a variable number of arguments:
334 eval "print $arg%d", $i
339 * Target descriptions can now describe registers for sparc32 and sparc64.
341 * GDB now supports DWARF version 5 (debug information format).
342 Its .debug_names index is not yet supported.
344 * New native configurations
346 FreeBSD/mips mips*-*-freebsd
350 Synopsys ARC arc*-*-elf32
351 FreeBSD/mips mips*-*-freebsd
353 * Removed targets and native configurations
355 Alpha running FreeBSD alpha*-*-freebsd*
356 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
361 Erases all the flash memory regions reported by the target.
363 maint print arc arc-instruction address
364 Print internal disassembler information about instruction at a given address.
368 set disassembler-options
369 show disassembler-options
370 Controls the passing of target specific information to the disassembler.
371 If it is necessary to specify more than one disassembler option then
372 multiple options can be placed together into a comma separated list.
373 The default value is the empty string. Currently, the only supported
374 targets are ARM, PowerPC and S/390.
379 Erases all the flash memory regions reported by the target. This is
380 equivalent to the CLI command flash-erase.
382 -file-list-shared-libraries
383 List the shared libraries in the program. This is
384 equivalent to the CLI command "info shared".
387 Catchpoints stopping the program when Ada exceptions are
388 handled. This is equivalent to the CLI command "catch handlers".
390 *** Changes in GDB 7.12
392 * GDB and GDBserver now build with a C++ compiler by default.
394 The --enable-build-with-cxx configure option is now enabled by
395 default. One must now explicitly configure with
396 --disable-build-with-cxx in order to build with a C compiler. This
397 option will be removed in a future release.
399 * GDBserver now supports recording btrace without maintaining an active
402 * GDB now supports a negative repeat count in the 'x' command to examine
403 memory backward from the given address. For example:
406 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
407 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
408 (gdb) x/-5i 0x0000000000400580
409 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
410 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
411 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
412 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
413 0x40057b <main(int, char**)+25>:
414 callq 0x400536 <Func1(int, char const*)>
416 * Fortran: Support structures with fields of dynamic types and
417 arrays of dynamic types.
419 * The symbol dumping maintenance commands have new syntax.
420 maint print symbols [-pc address] [--] [filename]
421 maint print symbols [-objfile objfile] [-source source] [--] [filename]
422 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
423 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
424 maint print msymbols [-objfile objfile] [--] [filename]
426 * GDB now supports multibit bitfields and enums in target register
429 * New Python-based convenience function $_as_string(val), which returns
430 the textual representation of a value. This function is especially
431 useful to obtain the text label of an enum value.
433 * Intel MPX bound violation handling.
435 Segmentation faults caused by a Intel MPX boundary violation
436 now display the kind of violation (upper or lower), the memory
437 address accessed and the memory bounds, along with the usual
438 signal received and code location.
442 Program received signal SIGSEGV, Segmentation fault
443 Upper bound violation while accessing address 0x7fffffffc3b3
444 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
445 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
447 * Rust language support.
448 GDB now supports debugging programs written in the Rust programming
449 language. See https://www.rust-lang.org/ for more information about
452 * Support for running interpreters on specified input/output devices
454 GDB now supports a new mechanism that allows frontends to provide
455 fully featured GDB console views, as a better alternative to
456 building such views on top of the "-interpreter-exec console"
457 command. See the new "new-ui" command below. With that command,
458 frontends can now start GDB in the traditional command-line mode
459 running in an embedded terminal emulator widget, and create a
460 separate MI interpreter running on a specified i/o device. In this
461 way, GDB handles line editing, history, tab completion, etc. in the
462 console all by itself, and the GUI uses the separate MI interpreter
463 for its own control and synchronization, invisible to the command
466 * The "catch syscall" command catches groups of related syscalls.
468 The "catch syscall" command now supports catching a group of related
469 syscalls using the 'group:' or 'g:' prefix.
474 skip -gfile file-glob-pattern
475 skip -function function
476 skip -rfunction regular-expression
477 A generalized form of the skip command, with new support for
478 glob-style file names and regular expressions for function names.
479 Additionally, a file spec and a function spec may now be combined.
481 maint info line-table REGEXP
482 Display the contents of GDB's internal line table data struture.
485 Run any GDB unit tests that were compiled in.
488 Start a new user interface instance running INTERP as interpreter,
489 using the TTY file for input/output.
493 ** gdb.Breakpoint objects have a new attribute "pending", which
494 indicates whether the breakpoint is pending.
495 ** Three new breakpoint-related events have been added:
496 gdb.breakpoint_created, gdb.breakpoint_modified, and
497 gdb.breakpoint_deleted.
500 Signal ("set") the given MS-Windows event object. This is used in
501 conjunction with the Windows JIT debugging (AeDebug) support, where
502 the OS suspends a crashing process until a debugger can attach to
503 it. Resuming the crashing process, in order to debug it, is done by
506 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
507 was added in GDBserver, including JIT compiling fast tracepoint's
508 conditional expression bytecode into native code.
510 * Support for various remote target protocols and ROM monitors has
513 target m32rsdi Remote M32R debugging over SDI
514 target mips MIPS remote debugging protocol
515 target pmon PMON ROM monitor
516 target ddb NEC's DDB variant of PMON for Vr4300
517 target rockhopper NEC RockHopper variant of PMON
518 target lsi LSI variant of PMO
520 * Support for tracepoints and fast tracepoints on powerpc-linux,
521 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
522 including JIT compiling fast tracepoint's conditional expression
523 bytecode into native code.
525 * MI async record =record-started now includes the method and format used for
526 recording. For example:
528 =record-started,thread-group="i1",method="btrace",format="bts"
530 * MI async record =thread-selected now includes the frame field. For example:
532 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
536 Andes NDS32 nds32*-*-elf
538 *** Changes in GDB 7.11
540 * GDB now supports debugging kernel-based threads on FreeBSD.
542 * Per-inferior thread numbers
544 Thread numbers are now per inferior instead of global. If you're
545 debugging multiple inferiors, GDB displays thread IDs using a
546 qualified INF_NUM.THR_NUM form. For example:
550 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
551 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
552 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
553 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
555 As consequence, thread numbers as visible in the $_thread
556 convenience variable and in Python's InferiorThread.num attribute
557 are no longer unique between inferiors.
559 GDB now maintains a second thread ID per thread, referred to as the
560 global thread ID, which is the new equivalent of thread numbers in
561 previous releases. See also $_gthread below.
563 For backwards compatibility, MI's thread IDs always refer to global
566 * Commands that accept thread IDs now accept the qualified
567 INF_NUM.THR_NUM form as well. For example:
570 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
573 * In commands that accept a list of thread IDs, you can now refer to
574 all threads of an inferior using a star wildcard. GDB accepts
575 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
576 refer to all threads of the current inferior. For example, "info
579 * You can use "info threads -gid" to display the global thread ID of
582 * The new convenience variable $_gthread holds the global number of
585 * The new convenience variable $_inferior holds the number of the
588 * GDB now displays the ID and name of the thread that hit a breakpoint
589 or received a signal, if your program is multi-threaded. For
592 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
593 Thread 1 "main" received signal SIGINT, Interrupt.
595 * Record btrace now supports non-stop mode.
597 * Support for tracepoints on aarch64-linux was added in GDBserver.
599 * The 'record instruction-history' command now indicates speculative execution
600 when using the Intel Processor Trace recording format.
602 * GDB now allows users to specify explicit locations, bypassing
603 the linespec parser. This feature is also available to GDB/MI
606 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
607 GDB now is able to debug both AArch64 applications and ARM applications
610 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
611 including JIT compiling fast tracepoint's conditional expression bytecode
614 * GDB now supports displaced stepping on AArch64 GNU/Linux.
616 * "info threads", "info inferiors", "info display", "info checkpoints"
617 and "maint info program-spaces" now list the corresponding items in
618 ascending ID order, for consistency with all other "info" commands.
620 * In Ada, the overloads selection menu has been enhanced to display the
621 parameter types and the return types for the matching overloaded subprograms.
625 maint set target-non-stop (on|off|auto)
626 maint show target-non-stop
627 Control whether GDB targets always operate in non-stop mode even if
628 "set non-stop" is "off". The default is "auto", meaning non-stop
629 mode is enabled if supported by the target.
631 maint set bfd-sharing
632 maint show bfd-sharing
633 Control the reuse of bfd objects.
637 Control display of debugging info regarding bfd caching.
641 Control display of debugging info regarding FreeBSD threads.
643 set remote multiprocess-extensions-packet
644 show remote multiprocess-extensions-packet
645 Set/show the use of the remote protocol multiprocess extensions.
647 set remote thread-events
648 show remote thread-events
649 Set/show the use of thread create/exit events.
651 set ada print-signatures on|off
652 show ada print-signatures"
653 Control whether parameter types and return types are displayed in overloads
654 selection menus. It is activaled (@code{on}) by default.
658 Controls the maximum size of memory, in bytes, that GDB will
659 allocate for value contents. Prevents incorrect programs from
660 causing GDB to allocate overly large buffers. Default is 64k.
662 * The "disassemble" command accepts a new modifier: /s.
663 It prints mixed source+disassembly like /m with two differences:
664 - disassembled instructions are now printed in program order, and
665 - and source for all relevant files is now printed.
666 The "/m" option is now considered deprecated: its "source-centric"
667 output hasn't proved useful in practice.
669 * The "record instruction-history" command accepts a new modifier: /s.
670 It behaves exactly like /m and prints mixed source+disassembly.
672 * The "set scheduler-locking" command supports a new mode "replay".
673 It behaves like "off" in record mode and like "on" in replay mode.
675 * Support for various ROM monitors has been removed:
677 target dbug dBUG ROM monitor for Motorola ColdFire
678 target picobug Motorola picobug monitor
679 target dink32 DINK32 ROM monitor for PowerPC
680 target m32r Renesas M32R/D ROM monitor
681 target mon2000 mon2000 ROM monitor
682 target ppcbug PPCBUG ROM monitor for PowerPC
684 * Support for reading/writing memory and extracting values on architectures
685 whose memory is addressable in units of any integral multiple of 8 bits.
688 Allows to break when an Ada exception is handled.
693 Indicates that an exec system call was executed.
695 exec-events feature in qSupported
696 The qSupported packet allows GDB to request support for exec
697 events using the new 'gdbfeature' exec-event, and the qSupported
698 response can contain the corresponding 'stubfeature'. Set and
699 show commands can be used to display whether these features are enabled.
702 Equivalent to interrupting with the ^C character, but works in
705 thread created stop reason (T05 create:...)
706 Indicates that the thread was just created and is stopped at entry.
708 thread exit stop reply (w exitcode;tid)
709 Indicates that the thread has terminated.
712 Enables/disables thread create and exit event reporting. For
713 example, this is used in non-stop mode when GDB stops a set of
714 threads and synchronously waits for the their corresponding stop
715 replies. Without exit events, if one of the threads exits, GDB
716 would hang forever not knowing that it should no longer expect a
717 stop for that same thread.
720 Indicates that there are no resumed threads left in the target (all
721 threads are stopped). The remote stub reports support for this stop
722 reply to GDB's qSupported query.
725 Enables/disables catching syscalls from the inferior process.
726 The remote stub reports support for this packet to GDB's qSupported query.
728 syscall_entry stop reason
729 Indicates that a syscall was just called.
731 syscall_return stop reason
732 Indicates that a syscall just returned.
734 * Extended-remote exec events
736 ** GDB now has support for exec events on extended-remote Linux targets.
737 For such targets with Linux kernels 2.5.46 and later, this enables
738 follow-exec-mode and exec catchpoints.
740 set remote exec-event-feature-packet
741 show remote exec-event-feature-packet
742 Set/show the use of the remote exec event feature.
744 * Thread names in remote protocol
746 The reply to qXfer:threads:read may now include a name attribute for each
749 * Target remote mode fork and exec events
751 ** GDB now has support for fork and exec events on target remote mode
752 Linux targets. For such targets with Linux kernels 2.5.46 and later,
753 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
754 fork and exec catchpoints.
756 * Remote syscall events
758 ** GDB now has support for catch syscall on remote Linux targets,
759 currently enabled on x86/x86_64 architectures.
761 set remote catch-syscall-packet
762 show remote catch-syscall-packet
763 Set/show the use of the remote catch syscall feature.
767 ** The -var-set-format command now accepts the zero-hexadecimal
768 format. It outputs data in hexadecimal format with zero-padding on the
773 ** gdb.InferiorThread objects have a new attribute "global_num",
774 which refers to the thread's global thread ID. The existing
775 "num" attribute now refers to the thread's per-inferior number.
776 See "Per-inferior thread numbers" above.
777 ** gdb.InferiorThread objects have a new attribute "inferior", which
778 is the Inferior object the thread belongs to.
780 *** Changes in GDB 7.10
782 * Support for process record-replay and reverse debugging on aarch64*-linux*
783 targets has been added. GDB now supports recording of A64 instruction set
784 including advance SIMD instructions.
786 * Support for Sun's version of the "stabs" debug file format has been removed.
788 * GDB now honors the content of the file /proc/PID/coredump_filter
789 (PID is the process ID) on GNU/Linux systems. This file can be used
790 to specify the types of memory mappings that will be included in a
791 corefile. For more information, please refer to the manual page of
792 "core(5)". GDB also has a new command: "set use-coredump-filter
793 on|off". It allows to set whether GDB will read the content of the
794 /proc/PID/coredump_filter file when generating a corefile.
796 * The "info os" command on GNU/Linux can now display information on
798 "info os cpus" Listing of all cpus/cores on the system
800 * GDB has two new commands: "set serial parity odd|even|none" and
801 "show serial parity". These allows to set or show parity for the
804 * The "info source" command now displays the producer string if it was
805 present in the debug info. This typically includes the compiler version
806 and may include things like its command line arguments.
808 * The "info dll", an alias of the "info sharedlibrary" command,
809 is now available on all platforms.
811 * Directory names supplied to the "set sysroot" commands may be
812 prefixed with "target:" to tell GDB to access shared libraries from
813 the target system, be it local or remote. This replaces the prefix
814 "remote:". The default sysroot has been changed from "" to
815 "target:". "remote:" is automatically converted to "target:" for
816 backward compatibility.
818 * The system root specified by "set sysroot" will be prepended to the
819 filename of the main executable (if reported to GDB as absolute by
820 the operating system) when starting processes remotely, and when
821 attaching to already-running local or remote processes.
823 * GDB now supports automatic location and retrieval of executable
824 files from remote targets. Remote debugging can now be initiated
825 using only a "target remote" or "target extended-remote" command
826 (no "set sysroot" or "file" commands are required). See "New remote
829 * The "dump" command now supports verilog hex format.
831 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
833 * On GNU/Linux, GDB and gdbserver are now able to access executable
834 and shared library files without a "set sysroot" command when
835 attaching to processes running in different mount namespaces from
836 the debugger. This makes it possible to attach to processes in
837 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
838 See "New remote packets" below.
840 * The "tui reg" command now provides completion for all of the
841 available register groups, including target specific groups.
843 * The HISTSIZE environment variable is no longer read when determining
844 the size of GDB's command history. GDB now instead reads the dedicated
845 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
846 disables truncation of command history. Non-numeric values of GDBHISTSIZE
851 ** Memory ports can now be unbuffered.
855 ** gdb.Objfile objects have a new attribute "username",
856 which is the name of the objfile as specified by the user,
857 without, for example, resolving symlinks.
858 ** You can now write frame unwinders in Python.
859 ** gdb.Type objects have a new method "optimized_out",
860 returning optimized out gdb.Value instance of this type.
861 ** gdb.Value objects have new methods "reference_value" and
862 "const_value" which return a reference to the value and a
863 "const" version of the value respectively.
867 maint print symbol-cache
868 Print the contents of the symbol cache.
870 maint print symbol-cache-statistics
871 Print statistics of symbol cache usage.
873 maint flush-symbol-cache
874 Flush the contents of the symbol cache.
878 Start branch trace recording using Branch Trace Store (BTS) format.
881 Evaluate expression by using the compiler and print result.
885 Explicit commands for enabling and disabling tui mode.
888 set mpx bound on i386 and amd64
889 Support for bound table investigation on Intel MPX enabled applications.
893 Start branch trace recording using Intel Processor Trace format.
896 Print information about branch tracing internals.
898 maint btrace packet-history
899 Print the raw branch tracing data.
901 maint btrace clear-packet-history
902 Discard the stored raw branch tracing data.
905 Discard all branch tracing data. It will be fetched and processed
906 anew by the next "record" command.
911 Renamed from "set debug dwarf2-die".
913 Renamed from "show debug dwarf2-die".
916 Renamed from "set debug dwarf2-read".
917 show debug dwarf-read
918 Renamed from "show debug dwarf2-read".
920 maint set dwarf always-disassemble
921 Renamed from "maint set dwarf2 always-disassemble".
922 maint show dwarf always-disassemble
923 Renamed from "maint show dwarf2 always-disassemble".
925 maint set dwarf max-cache-age
926 Renamed from "maint set dwarf2 max-cache-age".
927 maint show dwarf max-cache-age
928 Renamed from "maint show dwarf2 max-cache-age".
931 show debug dwarf-line
932 Control display of debugging info regarding DWARF line processing.
936 Set the maximum number of candidates to be considered during
937 completion. The default value is 200. This limit allows GDB
938 to avoid generating large completion lists, the computation of
939 which can cause the debugger to become temporarily unresponsive.
941 set history remove-duplicates
942 show history remove-duplicates
943 Control the removal of duplicate history entries.
945 maint set symbol-cache-size
946 maint show symbol-cache-size
947 Control the size of the symbol cache.
949 set|show record btrace bts buffer-size
950 Set and show the size of the ring buffer used for branch tracing in
952 The obtained size may differ from the requested size. Use "info
953 record" to see the obtained buffer size.
955 set debug linux-namespaces
956 show debug linux-namespaces
957 Control display of debugging info regarding Linux namespaces.
959 set|show record btrace pt buffer-size
960 Set and show the size of the ring buffer used for branch tracing in
961 Intel Processor Trace format.
962 The obtained size may differ from the requested size. Use "info
963 record" to see the obtained buffer size.
965 maint set|show btrace pt skip-pad
966 Set and show whether PAD packets are skipped when computing the
969 * The command 'thread apply all' can now support new option '-ascending'
970 to call its specified command for all threads in ascending order.
972 * Python/Guile scripting
974 ** GDB now supports auto-loading of Python/Guile scripts contained in the
975 special section named `.debug_gdb_scripts'.
979 qXfer:btrace-conf:read
980 Return the branch trace configuration for the current thread.
982 Qbtrace-conf:bts:size
983 Set the requested ring buffer size for branch tracing in BTS format.
986 Enable Intel Procesor Trace-based branch tracing for the current
987 process. The remote stub reports support for this packet to GDB's
991 Set the requested ring buffer size for branch tracing in Intel Processor
995 Indicates a memory breakpoint instruction was executed, irrespective
996 of whether it was GDB that planted the breakpoint or the breakpoint
997 is hardcoded in the program. This is required for correct non-stop
1001 Indicates the target stopped for a hardware breakpoint. This is
1002 required for correct non-stop mode operation.
1005 Return information about files on the remote system.
1007 qXfer:exec-file:read
1008 Return the full absolute name of the file that was executed to
1009 create a process running on the remote system.
1012 Select the filesystem on which vFile: operations with filename
1013 arguments will operate. This is required for GDB to be able to
1014 access files on remote targets where the remote stub does not
1015 share a common filesystem with the inferior(s).
1018 Indicates that a fork system call was executed.
1021 Indicates that a vfork system call was executed.
1023 vforkdone stop reason
1024 Indicates that a vfork child of the specified process has executed
1025 an exec or exit, allowing the vfork parent to resume execution.
1027 fork-events and vfork-events features in qSupported
1028 The qSupported packet allows GDB to request support for fork and
1029 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1030 and the qSupported response can contain the corresponding
1031 'stubfeatures'. Set and show commands can be used to display
1032 whether these features are enabled.
1034 * Extended-remote fork events
1036 ** GDB now has support for fork events on extended-remote Linux
1037 targets. For targets with Linux kernels 2.5.60 and later, this
1038 enables follow-fork-mode and detach-on-fork for both fork and
1039 vfork, as well as fork and vfork catchpoints.
1041 * The info record command now shows the recording format and the
1042 branch tracing configuration for the current thread when using
1043 the btrace record target.
1044 For the BTS format, it shows the ring buffer size.
1046 * GDB now has support for DTrace USDT (Userland Static Defined
1047 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1049 * GDB now supports access to vector registers on S/390 GNU/Linux
1052 * Removed command line options
1054 -xdb HP-UX XDB compatibility mode.
1056 * Removed targets and native configurations
1058 HP/PA running HP-UX hppa*-*-hpux*
1059 Itanium running HP-UX ia64-*-hpux*
1061 * New configure options
1064 This configure option allows the user to build GDB with support for
1065 Intel Processor Trace (default: auto). This requires libipt.
1067 --with-libipt-prefix=PATH
1068 Specify the path to the version of libipt that GDB should use.
1069 $PATH/include should contain the intel-pt.h header and
1070 $PATH/lib should contain the libipt.so library.
1072 *** Changes in GDB 7.9.1
1076 ** Xmethods can now specify a result type.
1078 *** Changes in GDB 7.9
1080 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1084 ** You can now access frame registers from Python scripts.
1085 ** New attribute 'producer' for gdb.Symtab objects.
1086 ** gdb.Objfile objects have a new attribute "progspace",
1087 which is the gdb.Progspace object of the containing program space.
1088 ** gdb.Objfile objects have a new attribute "owner".
1089 ** gdb.Objfile objects have a new attribute "build_id",
1090 which is the build ID generated when the file was built.
1091 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1092 ** A new event "gdb.clear_objfiles" has been added, triggered when
1093 selecting a new file to debug.
1094 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1095 ** New function gdb.lookup_objfile.
1097 New events which are triggered when GDB modifies the state of the
1100 ** gdb.events.inferior_call_pre: Function call is about to be made.
1101 ** gdb.events.inferior_call_post: Function call has just been made.
1102 ** gdb.events.memory_changed: A memory location has been altered.
1103 ** gdb.events.register_changed: A register has been altered.
1105 * New Python-based convenience functions:
1107 ** $_caller_is(name [, number_of_frames])
1108 ** $_caller_matches(regexp [, number_of_frames])
1109 ** $_any_caller_is(name [, number_of_frames])
1110 ** $_any_caller_matches(regexp [, number_of_frames])
1112 * GDB now supports the compilation and injection of source code into
1113 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1114 to compile the source code to object code, and if successful, inject
1115 and execute that code within the current context of the inferior.
1116 Currently the C language is supported. The commands used to
1117 interface with this new feature are:
1119 compile code [-raw|-r] [--] [source code]
1120 compile file [-raw|-r] filename
1124 demangle [-l language] [--] name
1125 Demangle "name" in the specified language, or the current language
1126 if elided. This command is renamed from the "maint demangle" command.
1127 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1128 as "maint demangler-warning".
1130 queue-signal signal-name-or-number
1131 Queue a signal to be delivered to the thread when it is resumed.
1133 add-auto-load-scripts-directory directory
1134 Add entries to the list of directories from which to load auto-loaded
1137 maint print user-registers
1138 List all currently available "user" registers.
1140 compile code [-r|-raw] [--] [source code]
1141 Compile, inject, and execute in the inferior the executable object
1142 code produced by compiling the provided source code.
1144 compile file [-r|-raw] filename
1145 Compile and inject into the inferior the executable object code
1146 produced by compiling the source code stored in the filename
1149 * On resume, GDB now always passes the signal the program had stopped
1150 for to the thread the signal was sent to, even if the user changed
1151 threads before resuming. Previously GDB would often (but not
1152 always) deliver the signal to the thread that happens to be current
1155 * Conversely, the "signal" command now consistently delivers the
1156 requested signal to the current thread. GDB now asks for
1157 confirmation if the program had stopped for a signal and the user
1158 switched threads meanwhile.
1160 * "breakpoint always-inserted" modes "off" and "auto" merged.
1162 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1163 won't remove breakpoints from the target until all threads stop,
1164 even in non-stop mode. The "auto" mode has been removed, and "off"
1165 is now the default mode.
1169 set debug symbol-lookup
1170 show debug symbol-lookup
1171 Control display of debugging info regarding symbol lookup.
1175 ** The -list-thread-groups command outputs an exit-code field for
1176 inferiors that have exited.
1180 MIPS SDE mips*-sde*-elf*
1184 Support for these obsolete configurations has been removed.
1186 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1187 SGI Irix-5.x mips-*-irix5*
1188 SGI Irix-6.x mips-*-irix6*
1189 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1190 VAX running Ultrix vax-*-ultrix*
1192 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1193 and "assf"), have been removed. Use the "sharedlibrary" command, or
1194 its alias "share", instead.
1196 *** Changes in GDB 7.8
1198 * New command line options
1201 This is an alias for the --data-directory option.
1203 * GDB supports printing and modifying of variable length automatic arrays
1204 as specified in ISO C99.
1206 * The ARM simulator now supports instruction level tracing
1207 with or without disassembly.
1211 GDB now has support for scripting using Guile. Whether this is
1212 available is determined at configure time.
1213 Guile version 2.0 or greater is required.
1214 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1216 * New commands (for set/show, see "New options" below)
1220 Invoke CODE by passing it to the Guile interpreter.
1224 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1226 info auto-load guile-scripts [regexp]
1227 Print the list of automatically loaded Guile scripts.
1229 * The source command is now capable of sourcing Guile scripts.
1230 This feature is dependent on the debugger being built with Guile support.
1234 set print symbol-loading (off|brief|full)
1235 show print symbol-loading
1236 Control whether to print informational messages when loading symbol
1237 information for a file. The default is "full", but when debugging
1238 programs with large numbers of shared libraries the amount of output
1239 becomes less useful.
1241 set guile print-stack (none|message|full)
1242 show guile print-stack
1243 Show a stack trace when an error is encountered in a Guile script.
1245 set auto-load guile-scripts (on|off)
1246 show auto-load guile-scripts
1247 Control auto-loading of Guile script files.
1249 maint ada set ignore-descriptive-types (on|off)
1250 maint ada show ignore-descriptive-types
1251 Control whether the debugger should ignore descriptive types in Ada
1252 programs. The default is not to ignore the descriptive types. See
1253 the user manual for more details on descriptive types and the intended
1254 usage of this option.
1256 set auto-connect-native-target
1258 Control whether GDB is allowed to automatically connect to the
1259 native target for the run, attach, etc. commands when not connected
1260 to any target yet. See also "target native" below.
1262 set record btrace replay-memory-access (read-only|read-write)
1263 show record btrace replay-memory-access
1264 Control what memory accesses are allowed during replay.
1266 maint set target-async (on|off)
1267 maint show target-async
1268 This controls whether GDB targets operate in synchronous or
1269 asynchronous mode. Normally the default is asynchronous, if it is
1270 available; but this can be changed to more easily debug problems
1271 occurring only in synchronous mode.
1273 set mi-async (on|off)
1275 Control whether MI asynchronous mode is preferred. This supersedes
1276 "set target-async" of previous GDB versions.
1278 * "set target-async" is deprecated as a CLI option and is now an alias
1279 for "set mi-async" (only puts MI into async mode).
1281 * Background execution commands (e.g., "c&", "s&", etc.) are now
1282 possible ``out of the box'' if the target supports them. Previously
1283 the user would need to explicitly enable the possibility with the
1284 "set target-async on" command.
1286 * New features in the GDB remote stub, GDBserver
1288 ** New option --debug-format=option1[,option2,...] allows one to add
1289 additional text to each output. At present only timestamps
1290 are supported: --debug-format=timestamps.
1291 Timestamps can also be turned on with the
1292 "monitor set debug-format timestamps" command from GDB.
1294 * The 'record instruction-history' command now starts counting instructions
1295 at one. This also affects the instruction ranges reported by the
1296 'record function-call-history' command when given the /i modifier.
1298 * The command 'record function-call-history' supports a new modifier '/c' to
1299 indent the function names based on their call stack depth.
1300 The fields for the '/i' and '/l' modifier have been reordered.
1301 The source line range is now prefixed with 'at'.
1302 The instruction range is now prefixed with 'inst'.
1303 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1304 "record instruction-history" and "list" commands.
1306 * The ranges given as arguments to the 'record function-call-history' and
1307 'record instruction-history' commands are now inclusive.
1309 * The btrace record target now supports the 'record goto' command.
1310 For locations inside the execution trace, the back trace is computed
1311 based on the information stored in the execution trace.
1313 * The btrace record target supports limited reverse execution and replay.
1314 The target does not record data and therefore does not allow reading
1315 memory or registers.
1317 * The "catch syscall" command now works on s390*-linux* targets.
1319 * The "compare-sections" command is no longer specific to target
1320 remote. It now works with all targets.
1322 * All native targets are now consistently called "native".
1323 Consequently, the "target child", "target GNU", "target djgpp",
1324 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1325 commands have been replaced with "target native". The QNX/NTO port
1326 leaves the "procfs" target in place and adds a "native" target for
1327 consistency with other ports. The impact on users should be minimal
1328 as these commands previously either throwed an error, or were
1329 no-ops. The target's name is visible in the output of the following
1330 commands: "help target", "info target", "info files", "maint print
1333 * The "target native" command now connects to the native target. This
1334 can be used to launch native programs even when "set
1335 auto-connect-native-target" is set to off.
1337 * GDB now supports access to Intel MPX registers on GNU/Linux.
1339 * Support for Intel AVX-512 registers on GNU/Linux.
1340 Support displaying and modifying Intel AVX-512 registers
1341 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1343 * New remote packets
1345 qXfer:btrace:read's annex
1346 The qXfer:btrace:read packet supports a new annex 'delta' to read
1347 branch trace incrementally.
1351 ** Valid Python operations on gdb.Value objects representing
1352 structs/classes invoke the corresponding overloaded operators if
1354 ** New `Xmethods' feature in the Python API. Xmethods are
1355 additional methods or replacements for existing methods of a C++
1356 class. This feature is useful for those cases where a method
1357 defined in C++ source code could be inlined or optimized out by
1358 the compiler, making it unavailable to GDB.
1361 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1363 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1364 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1365 its alias "share", instead.
1367 * The commands "set remotebaud" and "show remotebaud" are no longer
1368 supported. Use "set serial baud" and "show serial baud" (respectively)
1373 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1374 target-async". The latter is left as a deprecated alias of the
1375 former for backward compatibility. If the target supports it,
1376 CLI background execution commands are now always possible by
1377 default, independently of whether the frontend stated a
1378 preference for asynchronous execution with "-gdb-set mi-async".
1379 Previously "-gdb-set target-async off" affected both MI execution
1380 commands and CLI execution commands.
1382 *** Changes in GDB 7.7
1384 * Improved support for process record-replay and reverse debugging on
1385 arm*-linux* targets. Support for thumb32 and syscall instruction
1386 recording has been added.
1388 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1390 * GDB now supports Fission DWP file format version 2.
1391 http://gcc.gnu.org/wiki/DebugFission
1393 * New convenience function "$_isvoid", to check whether an expression
1394 is void. A void expression is an expression where the type of the
1395 result is "void". For example, some convenience variables may be
1396 "void" when evaluated (e.g., "$_exitcode" before the execution of
1397 the program being debugged; or an undefined convenience variable).
1398 Another example, when calling a function whose return type is
1401 * The "maintenance print objfiles" command now takes an optional regexp.
1403 * The "catch syscall" command now works on arm*-linux* targets.
1405 * GDB now consistently shows "<not saved>" when printing values of
1406 registers the debug info indicates have not been saved in the frame
1407 and there's nowhere to retrieve them from
1408 (callee-saved/call-clobbered registers):
1413 (gdb) info registers rax
1416 Before, the former would print "<optimized out>", and the latter
1417 "*value not available*".
1419 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1424 ** Frame filters and frame decorators have been added.
1425 ** Temporary breakpoints are now supported.
1426 ** Line tables representation has been added.
1427 ** New attribute 'parent_type' for gdb.Field objects.
1428 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1429 ** New attribute 'name' for gdb.Type objects.
1433 Nios II ELF nios2*-*-elf
1434 Nios II GNU/Linux nios2*-*-linux
1435 Texas Instruments MSP430 msp430*-*-elf
1437 * Removed native configurations
1439 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1440 been removed. ELF variants of these configurations are kept supported.
1442 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1443 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1444 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1445 i[34567]86-*-openbsd3.[0-3]
1446 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1447 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1448 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1452 Like "catch throw", but catches a re-thrown exception.
1453 maint check-psymtabs
1454 Renamed from old "maint check-symtabs".
1456 Perform consistency checks on symtabs.
1457 maint expand-symtabs
1458 Expand symtabs matching an optional regexp.
1461 Display the details of GDB configure-time options.
1463 maint set|show per-command
1464 maint set|show per-command space
1465 maint set|show per-command time
1466 maint set|show per-command symtab
1467 Enable display of per-command gdb resource usage.
1469 remove-symbol-file FILENAME
1470 remove-symbol-file -a ADDRESS
1471 Remove a symbol file added via add-symbol-file. The file to remove
1472 can be identified by its filename or by an address that lies within
1473 the boundaries of this symbol file in memory.
1476 info exceptions REGEXP
1477 Display the list of Ada exceptions defined in the program being
1478 debugged. If provided, only the exceptions whose names match REGEXP
1483 set debug symfile off|on
1485 Control display of debugging info regarding reading symbol files and
1486 symbol tables within those files
1488 set print raw frame-arguments
1489 show print raw frame-arguments
1490 Set/show whether to print frame arguments in raw mode,
1491 disregarding any defined pretty-printers.
1493 set remote trace-status-packet
1494 show remote trace-status-packet
1495 Set/show the use of remote protocol qTStatus packet.
1499 Control display of debugging messages related to Nios II targets.
1503 Control whether target-assisted range stepping is enabled.
1505 set startup-with-shell
1506 show startup-with-shell
1507 Specifies whether Unix child processes are started via a shell or
1512 Use the target memory cache for accesses to the code segment. This
1513 improves performance of remote debugging (particularly disassembly).
1515 * You can now use a literal value 'unlimited' for options that
1516 interpret 0 or -1 as meaning "unlimited". E.g., "set
1517 trace-buffer-size unlimited" is now an alias for "set
1518 trace-buffer-size -1" and "set height unlimited" is now an alias for
1521 * The "set debug symtab-create" debugging option of GDB has been changed to
1522 accept a verbosity level. 0 means "off", 1 provides basic debugging
1523 output, and values of 2 or greater provides more verbose output.
1525 * New command-line options
1527 Display the details of GDB configure-time options.
1529 * The command 'tsave' can now support new option '-ctf' to save trace
1530 buffer in Common Trace Format.
1532 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1535 * GDB now implements the the C++ 'typeid' operator.
1537 * The new convenience variable $_exception holds the exception being
1538 thrown or caught at an exception-related catchpoint.
1540 * The exception-related catchpoints, like "catch throw", now accept a
1541 regular expression which can be used to filter exceptions by type.
1543 * The new convenience variable $_exitsignal is automatically set to
1544 the terminating signal number when the program being debugged dies
1545 due to an uncaught signal.
1549 ** All MI commands now accept an optional "--language" option.
1550 Support for this feature can be verified by using the "-list-features"
1551 command, which should contain "language-option".
1553 ** The new command -info-gdb-mi-command allows the user to determine
1554 whether a GDB/MI command is supported or not.
1556 ** The "^error" result record returned when trying to execute an undefined
1557 GDB/MI command now provides a variable named "code" whose content is the
1558 "undefined-command" error code. Support for this feature can be verified
1559 by using the "-list-features" command, which should contain
1560 "undefined-command-error-code".
1562 ** The -trace-save MI command can optionally save trace buffer in Common
1565 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1567 ** The command -data-list-register-values now accepts an optional
1568 "--skip-unavailable" option. When used, only the available registers
1571 ** The new command -trace-frame-collected dumps collected variables,
1572 computed expressions, tvars, memory and registers in a traceframe.
1574 ** The commands -stack-list-locals, -stack-list-arguments and
1575 -stack-list-variables now accept an option "--skip-unavailable".
1576 When used, only the available locals or arguments are displayed.
1578 ** The -exec-run command now accepts an optional "--start" option.
1579 When used, the command follows the same semantics as the "start"
1580 command, stopping the program's execution at the start of its
1581 main subprogram. Support for this feature can be verified using
1582 the "-list-features" command, which should contain
1583 "exec-run-start-option".
1585 ** The new commands -catch-assert and -catch-exceptions insert
1586 catchpoints stopping the program when Ada exceptions are raised.
1588 ** The new command -info-ada-exceptions provides the equivalent of
1589 the new "info exceptions" command.
1591 * New system-wide configuration scripts
1592 A GDB installation now provides scripts suitable for use as system-wide
1593 configuration scripts for the following systems:
1597 * GDB now supports target-assigned range stepping with remote targets.
1598 This improves the performance of stepping source lines by reducing
1599 the number of control packets from/to GDB. See "New remote packets"
1602 * GDB now understands the element 'tvar' in the XML traceframe info.
1603 It has the id of the collected trace state variables.
1605 * On S/390 targets that provide the transactional-execution feature,
1606 the program interruption transaction diagnostic block (TDB) is now
1607 represented as a number of additional "registers" in GDB.
1609 * New remote packets
1613 The vCont packet supports a new 'r' action, that tells the remote
1614 stub to step through an address range itself, without GDB
1615 involvemement at each single-step.
1617 qXfer:libraries-svr4:read's annex
1618 The previously unused annex of the qXfer:libraries-svr4:read packet
1619 is now used to support passing an argument list. The remote stub
1620 reports support for this argument list to GDB's qSupported query.
1621 The defined arguments are "start" and "prev", used to reduce work
1622 necessary for library list updating, resulting in significant
1625 * New features in the GDB remote stub, GDBserver
1627 ** GDBserver now supports target-assisted range stepping. Currently
1628 enabled on x86/x86_64 GNU/Linux targets.
1630 ** GDBserver now adds element 'tvar' in the XML in the reply to
1631 'qXfer:traceframe-info:read'. It has the id of the collected
1632 trace state variables.
1634 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1637 * New 'z' formatter for printing and examining memory, this displays the
1638 value as hexadecimal zero padded on the left to the size of the type.
1640 * GDB can now use Windows x64 unwinding data.
1642 * The "set remotebaud" command has been replaced by "set serial baud".
1643 Similarly, "show remotebaud" has been replaced by "show serial baud".
1644 The "set remotebaud" and "show remotebaud" commands are still available
1645 to provide backward compatibility with older versions of GDB.
1647 *** Changes in GDB 7.6
1649 * Target record has been renamed to record-full.
1650 Record/replay is now enabled with the "record full" command.
1651 This also affects settings that are associated with full record/replay
1652 that have been moved from "set/show record" to "set/show record full":
1654 set|show record full insn-number-max
1655 set|show record full stop-at-limit
1656 set|show record full memory-query
1658 * A new record target "record-btrace" has been added. The new target
1659 uses hardware support to record the control-flow of a process. It
1660 does not support replaying the execution, but it implements the
1661 below new commands for investigating the recorded execution log.
1662 This new recording method can be enabled using:
1666 The "record-btrace" target is only available on Intel Atom processors
1667 and requires a Linux kernel 2.6.32 or later.
1669 * Two new commands have been added for record/replay to give information
1670 about the recorded execution without having to replay the execution.
1671 The commands are only supported by "record btrace".
1673 record instruction-history prints the execution history at
1674 instruction granularity
1676 record function-call-history prints the execution history at
1677 function granularity
1679 * New native configurations
1681 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1682 FreeBSD/powerpc powerpc*-*-freebsd
1683 x86_64/Cygwin x86_64-*-cygwin*
1684 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1688 ARM AArch64 aarch64*-*-elf
1689 ARM AArch64 GNU/Linux aarch64*-*-linux
1690 Lynx 178 PowerPC powerpc-*-lynx*178
1691 x86_64/Cygwin x86_64-*-cygwin*
1692 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1694 * If the configured location of system.gdbinit file (as given by the
1695 --with-system-gdbinit option at configure time) is in the
1696 data-directory (as specified by --with-gdb-datadir at configure
1697 time) or in one of its subdirectories, then GDB will look for the
1698 system-wide init file in the directory specified by the
1699 --data-directory command-line option.
1701 * New command line options:
1703 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1704 other initialization files, unlike -nx which disables all of them.
1706 * Removed command line options
1708 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1711 * The 'ptype' and 'whatis' commands now accept an argument to control
1714 * 'info proc' now works on some core files.
1718 ** Vectors can be created with gdb.Type.vector.
1720 ** Python's atexit.register now works in GDB.
1722 ** Types can be pretty-printed via a Python API.
1724 ** Python 3 is now supported (in addition to Python 2.4 or later)
1726 ** New class gdb.Architecture exposes GDB's internal representation
1727 of architecture in the Python API.
1729 ** New method Frame.architecture returns the gdb.Architecture object
1730 corresponding to the frame's architecture.
1732 * New Python-based convenience functions:
1734 ** $_memeq(buf1, buf2, length)
1735 ** $_streq(str1, str2)
1737 ** $_regex(str, regex)
1739 * The 'cd' command now defaults to using '~' (the home directory) if not
1742 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1743 default for GCC since November 2000.
1745 * The command 'forward-search' can now be abbreviated as 'fo'.
1747 * The command 'info tracepoints' can now display 'installed on target'
1748 or 'not installed on target' for each non-pending location of tracepoint.
1750 * New configure options
1752 --enable-libmcheck/--disable-libmcheck
1753 By default, development versions are built with -lmcheck on hosts
1754 that support it, in order to help track memory corruption issues.
1755 Release versions, on the other hand, are built without -lmcheck
1756 by default. The --enable-libmcheck/--disable-libmcheck configure
1757 options allow the user to override that default.
1758 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1759 This configure option allows the user to build GDB with
1760 libbabeltrace using which GDB can read Common Trace Format data.
1762 * New commands (for set/show, see "New options" below)
1765 Catch signals. This is similar to "handle", but allows commands and
1766 conditions to be attached.
1769 List the BFDs known to GDB.
1771 python-interactive [command]
1773 Start a Python interactive prompt, or evaluate the optional command
1774 and print the result of expressions.
1777 "py" is a new alias for "python".
1779 enable type-printer [name]...
1780 disable type-printer [name]...
1781 Enable or disable type printers.
1785 ** For the Renesas Super-H architecture, the "regs" command has been removed
1786 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1791 set print type methods (on|off)
1792 show print type methods
1793 Control whether method declarations are displayed by "ptype".
1794 The default is to show them.
1796 set print type typedefs (on|off)
1797 show print type typedefs
1798 Control whether typedef definitions are displayed by "ptype".
1799 The default is to show them.
1801 set filename-display basename|relative|absolute
1802 show filename-display
1803 Control the way in which filenames is displayed.
1804 The default is "relative", which preserves previous behavior.
1806 set trace-buffer-size
1807 show trace-buffer-size
1808 Request target to change the size of trace buffer.
1810 set remote trace-buffer-size-packet auto|on|off
1811 show remote trace-buffer-size-packet
1812 Control the use of the remote protocol `QTBuffer:size' packet.
1816 Control display of debugging messages related to ARM AArch64.
1819 set debug coff-pe-read
1820 show debug coff-pe-read
1821 Control display of debugging messages related to reading of COFF/PE
1826 Control display of debugging messages related to Mach-O symbols
1829 set debug notification
1830 show debug notification
1831 Control display of debugging info for async remote notification.
1835 ** Command parameter changes are now notified using new async record
1836 "=cmd-param-changed".
1837 ** Trace frame changes caused by command "tfind" are now notified using
1838 new async record "=traceframe-changed".
1839 ** The creation, deletion and modification of trace state variables
1840 are now notified using new async records "=tsv-created",
1841 "=tsv-deleted" and "=tsv-modified".
1842 ** The start and stop of process record are now notified using new
1843 async record "=record-started" and "=record-stopped".
1844 ** Memory changes are now notified using new async record
1846 ** The data-disassemble command response will include a "fullname" field
1847 containing the absolute file name when source has been requested.
1848 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1849 command, to allow pattern filling of memory areas.
1850 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1851 library load/unload events.
1852 ** The response to breakpoint commands and breakpoint async records
1853 includes an "installed" field containing a boolean state about each
1854 non-pending tracepoint location is whether installed on target or not.
1855 ** Output of the "-trace-status" command includes a "trace-file" field
1856 containing the name of the trace file being examined. This field is
1857 optional, and only present when examining a trace file.
1858 ** The "fullname" field is now always present along with the "file" field,
1859 even if the file cannot be found by GDB.
1861 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1862 You must have the LZMA library available when configuring GDB for this
1863 feature to be enabled. For more information, see:
1864 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1866 * New remote packets
1869 Set the size of trace buffer. The remote stub reports support for this
1870 packet to gdb's qSupported query.
1873 Enable Branch Trace Store (BTS)-based branch tracing for the current
1874 thread. The remote stub reports support for this packet to gdb's
1878 Disable branch tracing for the current thread. The remote stub reports
1879 support for this packet to gdb's qSupported query.
1882 Read the traced branches for the current thread. The remote stub
1883 reports support for this packet to gdb's qSupported query.
1885 *** Changes in GDB 7.5
1887 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1888 for more x32 ABI info.
1890 * GDB now supports access to MIPS DSP registers on Linux targets.
1892 * GDB now supports debugging microMIPS binaries.
1894 * The "info os" command on GNU/Linux can now display information on
1895 several new classes of objects managed by the operating system:
1896 "info os procgroups" lists process groups
1897 "info os files" lists file descriptors
1898 "info os sockets" lists internet-domain sockets
1899 "info os shm" lists shared-memory regions
1900 "info os semaphores" lists semaphores
1901 "info os msg" lists message queues
1902 "info os modules" lists loaded kernel modules
1904 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1905 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1906 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1907 options and inspect the probe arguments using the new $_probe_arg family
1908 of convenience variables. You can obtain more information about SystemTap
1909 in <http://sourceware.org/systemtap/>.
1911 * GDB now supports reversible debugging on ARM, it allows you to
1912 debug basic ARM and THUMB instructions, and provides
1913 record/replay support.
1915 * The option "symbol-reloading" has been deleted as it is no longer used.
1919 ** GDB commands implemented in Python can now be put in command class
1922 ** The "maint set python print-stack on|off" is now deleted.
1924 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1925 apply "flag enum"-style pretty-printing to any enum.
1927 ** gdb.lookup_symbol can now work when there is no current frame.
1929 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1930 the source at which the symbol was defined.
1932 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1933 method 'value'. The former indicates whether the symbol needs a
1934 frame in order to compute its value, and the latter computes the
1937 ** A new method 'referenced_value' on gdb.Value objects which can
1938 dereference pointer as well as C++ reference values.
1940 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1941 which return the global and static blocks (as gdb.Block objects),
1942 of the underlying symbol table, respectively.
1944 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1945 object associated with a PC value.
1947 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1948 of the address range occupied by code for the current source line.
1950 * Go language support.
1951 GDB now supports debugging programs written in the Go programming
1954 * GDBserver now supports stdio connections.
1955 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1957 * The binary "gdbtui" can no longer be built or installed.
1958 Use "gdb -tui" instead.
1960 * GDB will now print "flag" enums specially. A flag enum is one where
1961 all the enumerator values have no bits in common when pairwise
1962 "and"ed. When printing a value whose type is a flag enum, GDB will
1963 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1964 (gdb) print (enum E) 3
1967 * The filename part of a linespec will now match trailing components
1968 of a source file name. For example, "break gcc/expr.c:1000" will
1969 now set a breakpoint in build/gcc/expr.c, but not
1970 build/libcpp/expr.c.
1972 * The "info proc" and "generate-core-file" commands will now also
1973 work on remote targets connected to GDBserver on Linux.
1975 * The command "info catch" has been removed. It has been disabled
1976 since December 2007.
1978 * The "catch exception" and "catch assert" commands now accept
1979 a condition at the end of the command, much like the "break"
1980 command does. For instance:
1982 (gdb) catch exception Constraint_Error if Barrier = True
1984 Previously, it was possible to add a condition to such catchpoints,
1985 but it had to be done as a second step, after the catchpoint had been
1986 created, using the "condition" command.
1988 * The "info static-tracepoint-marker" command will now also work on
1989 native Linux targets with in-process agent.
1991 * GDB can now set breakpoints on inlined functions.
1993 * The .gdb_index section has been updated to include symbols for
1994 inlined functions. GDB will ignore older .gdb_index sections by
1995 default, which could cause symbol files to be loaded more slowly
1996 until their .gdb_index sections can be recreated. The new command
1997 "set use-deprecated-index-sections on" will cause GDB to use any older
1998 .gdb_index sections it finds. This will restore performance, but the
1999 ability to set breakpoints on inlined functions will be lost in symbol
2000 files with older .gdb_index sections.
2002 The .gdb_index section has also been updated to record more information
2003 about each symbol. This speeds up the "info variables", "info functions"
2004 and "info types" commands when used with programs having the .gdb_index
2005 section, as well as speeding up debugging with shared libraries using
2006 the .gdb_index section.
2008 * Ada support for GDB/MI Variable Objects has been added.
2010 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2015 ** New command -info-os is the MI equivalent of "info os".
2017 ** Output logs ("set logging" and related) now include MI output.
2021 ** "set use-deprecated-index-sections on|off"
2022 "show use-deprecated-index-sections on|off"
2023 Controls the use of deprecated .gdb_index sections.
2025 ** "catch load" and "catch unload" can be used to stop when a shared
2026 library is loaded or unloaded, respectively.
2028 ** "enable count" can be used to auto-disable a breakpoint after
2031 ** "info vtbl" can be used to show the virtual method tables for
2032 C++ and Java objects.
2034 ** "explore" and its sub commands "explore value" and "explore type"
2035 can be used to recursively explore values and types of
2036 expressions. These commands are available only if GDB is
2037 configured with '--with-python'.
2039 ** "info auto-load" shows status of all kinds of auto-loaded files,
2040 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2041 sequences of commands files, "info auto-load python-scripts"
2042 shows status of auto-loading Python script files,
2043 "info auto-load local-gdbinit" shows status of loading init file
2044 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2045 status of inferior specific thread debugging shared library loading.
2047 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2048 and "show auto-load-scripts" commands have been deprecated, use their
2049 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2050 and "show auto-load python-scripts" counterparts instead.
2052 ** "dprintf location,format,args..." creates a dynamic printf, which
2053 is basically a breakpoint that does a printf and immediately
2054 resumes your program's execution, so it is like a printf that you
2055 can insert dynamically at runtime instead of at compiletime.
2057 ** "set print symbol"
2059 Controls whether GDB attempts to display the symbol, if any,
2060 corresponding to addresses it prints. This defaults to "on", but
2061 you can set it to "off" to restore GDB's previous behavior.
2063 * Deprecated commands
2065 ** For the Renesas Super-H architecture, the "regs" command has been
2066 deprecated, and "info all-registers" should be used instead.
2070 Renesas RL78 rl78-*-elf
2071 HP OpenVMS ia64 ia64-hp-openvms*
2073 * GDBserver supports evaluation of breakpoint conditions. When
2074 support is advertised by GDBserver, GDB may be told to send the
2075 breakpoint conditions in bytecode form to GDBserver. GDBserver
2076 will only report the breakpoint trigger to GDB when its condition
2081 set mips compression
2082 show mips compression
2083 Select the compressed ISA encoding used in functions that have no symbol
2084 information available. The encoding can be set to either of:
2087 and is updated automatically from ELF file flags if available.
2089 set breakpoint condition-evaluation
2090 show breakpoint condition-evaluation
2091 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2092 GDBserver ("target"). Default option "auto" chooses the most efficient
2094 This option can improve debugger efficiency depending on the speed of the
2098 Disable auto-loading globally.
2101 Show auto-loading setting of all kinds of auto-loaded files.
2103 set auto-load gdb-scripts on|off
2104 show auto-load gdb-scripts
2105 Control auto-loading of GDB canned sequences of commands files.
2107 set auto-load python-scripts on|off
2108 show auto-load python-scripts
2109 Control auto-loading of Python script files.
2111 set auto-load local-gdbinit on|off
2112 show auto-load local-gdbinit
2113 Control loading of init file (.gdbinit) from current directory.
2115 set auto-load libthread-db on|off
2116 show auto-load libthread-db
2117 Control auto-loading of inferior specific thread debugging shared library.
2119 set auto-load scripts-directory <dir1>[:<dir2>...]
2120 show auto-load scripts-directory
2121 Set a list of directories from which to load auto-loaded scripts.
2122 Automatically loaded Python scripts and GDB scripts are located in one
2123 of the directories listed by this option.
2124 The delimiter (':' above) may differ according to the host platform.
2126 set auto-load safe-path <dir1>[:<dir2>...]
2127 show auto-load safe-path
2128 Set a list of directories from which it is safe to auto-load files.
2129 The delimiter (':' above) may differ according to the host platform.
2131 set debug auto-load on|off
2132 show debug auto-load
2133 Control display of debugging info for auto-loading the files above.
2135 set dprintf-style gdb|call|agent
2137 Control the way in which a dynamic printf is performed; "gdb"
2138 requests a GDB printf command, while "call" causes dprintf to call a
2139 function in the inferior. "agent" requests that the target agent
2140 (such as GDBserver) do the printing.
2142 set dprintf-function <expr>
2143 show dprintf-function
2144 set dprintf-channel <expr>
2145 show dprintf-channel
2146 Set the function and optional first argument to the call when using
2147 the "call" style of dynamic printf.
2149 set disconnected-dprintf on|off
2150 show disconnected-dprintf
2151 Control whether agent-style dynamic printfs continue to be in effect
2152 after GDB disconnects.
2154 * New configure options
2156 --with-auto-load-dir
2157 Configure default value for the 'set auto-load scripts-directory'
2158 setting above. It defaults to '$debugdir:$datadir/auto-load',
2159 $debugdir representing global debugging info directories (available
2160 via 'show debug-file-directory') and $datadir representing GDB's data
2161 directory (available via 'show data-directory').
2163 --with-auto-load-safe-path
2164 Configure default value for the 'set auto-load safe-path' setting
2165 above. It defaults to the --with-auto-load-dir setting.
2167 --without-auto-load-safe-path
2168 Set 'set auto-load safe-path' to '/', effectively disabling this
2171 * New remote packets
2173 z0/z1 conditional breakpoints extension
2175 The z0/z1 breakpoint insertion packets have been extended to carry
2176 a list of conditional expressions over to the remote stub depending on the
2177 condition evaluation mode. The use of this extension can be controlled
2178 via the "set remote conditional-breakpoints-packet" command.
2182 Specify the signals which the remote stub may pass to the debugged
2183 program without GDB involvement.
2185 * New command line options
2187 --init-command=FILE, -ix Like --command, -x but execute it
2188 before loading inferior.
2189 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2190 execute it before loading inferior.
2192 *** Changes in GDB 7.4
2194 * GDB now handles ambiguous linespecs more consistently; the existing
2195 FILE:LINE support has been expanded to other types of linespecs. A
2196 breakpoint will now be set on all matching locations in all
2197 inferiors, and locations will be added or removed according to
2200 * GDB now allows you to skip uninteresting functions and files when
2201 stepping with the "skip function" and "skip file" commands.
2203 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2204 and "show remote hardware-watchpoint-length-limit". These allows to
2205 set or show the maximum length limit (in bytes) of a remote
2206 target hardware watchpoint.
2208 This allows e.g. to use "unlimited" hardware watchpoints with the
2209 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2210 watchpoints are slower than real hardware watchpoints but are
2211 significantly faster than gdb software watchpoints.
2215 ** The register_pretty_printer function in module gdb.printing now takes
2216 an optional `replace' argument. If True, the new printer replaces any
2219 ** The "maint set python print-stack on|off" command has been
2220 deprecated and will be deleted in GDB 7.5.
2221 A new command: "set python print-stack none|full|message" has
2222 replaced it. Additionally, the default for "print-stack" is
2223 now "message", which just prints the error message without
2226 ** A prompt substitution hook (prompt_hook) is now available to the
2229 ** A new Python module, gdb.prompt has been added to the GDB Python
2230 modules library. This module provides functionality for
2231 escape sequences in prompts (used by set/show
2232 extended-prompt). These escape sequences are replaced by their
2233 corresponding value.
2235 ** Python commands and convenience-functions located in
2236 'data-directory'/python/gdb/command and
2237 'data-directory'/python/gdb/function are now automatically loaded
2240 ** Blocks now provide four new attributes. global_block and
2241 static_block will return the global and static blocks
2242 respectively. is_static and is_global are boolean attributes
2243 that indicate if the block is one of those two types.
2245 ** Symbols now provide the "type" attribute, the type of the symbol.
2247 ** The "gdb.breakpoint" function has been deprecated in favor of
2250 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2251 of a function. This class is based on the "finish" command
2252 available in the CLI.
2254 ** Type objects for struct and union types now allow access to
2255 the fields using standard Python dictionary (mapping) methods.
2256 For example, "some_type['myfield']" now works, as does
2257 "some_type.items()".
2259 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2262 ** A new function, "deep_items" has been added to the gdb.types
2263 module in the GDB Python modules library. This function returns
2264 an iterator over the fields of a struct or union type. Unlike
2265 the standard Python "iteritems" method, it will recursively traverse
2266 any anonymous fields.
2270 ** "*stopped" events can report several new "reason"s, such as
2273 ** Breakpoint changes are now notified using new async records, like
2274 "=breakpoint-modified".
2276 ** New command -ada-task-info.
2278 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2279 $sdir specifies the default system locations of shared libraries.
2280 $pdir specifies the directory where the libpthread used by the application
2283 GDB no longer looks in $sdir and $pdir after it has searched the directories
2284 mentioned in libthread-db-search-path. If you want to search those
2285 directories, they must be specified in libthread-db-search-path.
2286 The default value of libthread-db-search-path on GNU/Linux and Solaris
2287 systems is now "$sdir:$pdir".
2289 $pdir is not supported by gdbserver, it is currently ignored.
2290 $sdir is supported by gdbserver.
2292 * New configure option --with-iconv-bin.
2293 When using the internationalization support like the one in the GNU C
2294 library, GDB will invoke the "iconv" program to get a list of supported
2295 character sets. If this program lives in a non-standard location, one can
2296 use this option to specify where to find it.
2298 * When natively debugging programs on PowerPC BookE processors running
2299 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2300 watchpoints, which specify a mask in addition to an address to watch.
2301 The mask specifies that some bits of an address (the bits which are
2302 reset in the mask) should be ignored when matching the address accessed
2303 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2304 section in the user manual for more details.
2306 * The new option --once causes GDBserver to stop listening for connections once
2307 the first connection is made. The listening port used by GDBserver will
2308 become available after that.
2310 * New commands "info macros" and "alias" have been added.
2312 * New function parameters suffix @entry specifies value of function parameter
2313 at the time the function got called. Entry values are available only since
2319 "!" is now an alias of the "shell" command.
2320 Note that no space is needed between "!" and SHELL COMMAND.
2324 watch EXPRESSION mask MASK_VALUE
2325 The watch command now supports the mask argument which allows creation
2326 of masked watchpoints, if the current architecture supports this feature.
2328 info auto-load-scripts [REGEXP]
2329 This command was formerly named "maintenance print section-scripts".
2330 It is now generally useful and is no longer a maintenance-only command.
2332 info macro [-all] [--] MACRO
2333 The info macro command has new options `-all' and `--'. The first for
2334 printing all definitions of a macro. The second for explicitly specifying
2335 the end of arguments and the beginning of the macro name in case the macro
2336 name starts with a hyphen.
2338 collect[/s] EXPRESSIONS
2339 The tracepoint collect command now takes an optional modifier "/s"
2340 that directs it to dereference pointer-to-character types and
2341 collect the bytes of memory up to a zero byte. The behavior is
2342 similar to what you see when you use the regular print command on a
2343 string. An optional integer following the "/s" sets a bound on the
2344 number of bytes that will be collected.
2347 The trace start command now interprets any supplied arguments as a
2348 note to be recorded with the trace run, with an effect similar to
2349 setting the variable trace-notes.
2352 The trace stop command now interprets any arguments as a note to be
2353 mentioned along with the tstatus report that the trace was stopped
2354 with a command. The effect is similar to setting the variable
2357 * Tracepoints can now be enabled and disabled at any time after a trace
2358 experiment has been started using the standard "enable" and "disable"
2359 commands. It is now possible to start a trace experiment with no enabled
2360 tracepoints; GDB will display a warning, but will allow the experiment to
2361 begin, assuming that tracepoints will be enabled as needed while the trace
2364 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2365 locations with 4-byte instructions, when they were previously
2366 limited to locations with instructions of 5 bytes or longer.
2370 set debug dwarf2-read
2371 show debug dwarf2-read
2372 Turns on or off display of debugging messages related to reading
2373 DWARF debug info. The default is off.
2375 set debug symtab-create
2376 show debug symtab-create
2377 Turns on or off display of debugging messages related to symbol table
2378 creation. The default is off.
2381 show extended-prompt
2382 Set the GDB prompt, and allow escape sequences to be inserted to
2383 display miscellaneous information (see 'help set extended-prompt'
2384 for the list of sequences). This prompt (and any information
2385 accessed through the escape sequences) is updated every time the
2386 prompt is displayed.
2388 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2389 show print entry-values
2390 Set printing of frame argument values at function entry. In some cases
2391 GDB can determine the value of function argument which was passed by the
2392 function caller, even if the value was modified inside the called function.
2394 set debug entry-values
2395 show debug entry-values
2396 Control display of debugging info for determining frame argument values at
2397 function entry and virtual tail call frames.
2399 set basenames-may-differ
2400 show basenames-may-differ
2401 Set whether a source file may have multiple base names.
2402 (A "base name" is the name of a file with the directory part removed.
2403 Example: The base name of "/home/user/hello.c" is "hello.c".)
2404 If set, GDB will canonicalize file names (e.g., expand symlinks)
2405 before comparing them. Canonicalization is an expensive operation,
2406 but it allows the same file be known by more than one base name.
2407 If not set (the default), all source files are assumed to have just
2408 one base name, and gdb will do file name comparisons more efficiently.
2414 Set a user name and notes for the current and any future trace runs.
2415 This is useful for long-running and/or disconnected traces, to
2416 inform others (or yourself) as to who is running the trace, supply
2417 contact information, or otherwise explain what is going on.
2419 set trace-stop-notes
2420 show trace-stop-notes
2421 Set a note attached to the trace run, that is displayed when the
2422 trace has been stopped by a tstop command. This is useful for
2423 instance as an explanation, if you are stopping a trace run that was
2424 started by someone else.
2426 * New remote packets
2430 Dynamically enable a tracepoint in a started trace experiment.
2434 Dynamically disable a tracepoint in a started trace experiment.
2438 Set the user and notes of the trace run.
2442 Query the current status of a tracepoint.
2446 Query the minimum length of instruction at which a fast tracepoint may
2449 * Dcache size (number of lines) and line-size are now runtime-configurable
2450 via "set dcache line" and "set dcache line-size" commands.
2454 Texas Instruments TMS320C6x tic6x-*-*
2458 Renesas RL78 rl78-*-elf
2460 *** Changes in GDB 7.3.1
2462 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2464 *** Changes in GDB 7.3
2466 * GDB has a new command: "thread find [REGEXP]".
2467 It finds the thread id whose name, target id, or thread extra info
2468 matches the given regular expression.
2470 * The "catch syscall" command now works on mips*-linux* targets.
2472 * The -data-disassemble MI command now supports modes 2 and 3 for
2473 dumping the instruction opcodes.
2475 * New command line options
2477 -data-directory DIR Specify DIR as the "data-directory".
2478 This is mostly for testing purposes.
2480 * The "maint set python auto-load on|off" command has been renamed to
2481 "set auto-load-scripts on|off".
2483 * GDB has a new command: "set directories".
2484 It is like the "dir" command except that it replaces the
2485 source path list instead of augmenting it.
2487 * GDB now understands thread names.
2489 On GNU/Linux, "info threads" will display the thread name as set by
2490 prctl or pthread_setname_np.
2492 There is also a new command, "thread name", which can be used to
2493 assign a name internally for GDB to display.
2496 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2497 has been integrated into GDB.
2501 ** The function gdb.Write now accepts an optional keyword 'stream'.
2502 This keyword, when provided, will direct the output to either
2503 stdout, stderr, or GDB's logging output.
2505 ** Parameters can now be be sub-classed in Python, and in particular
2506 you may implement the get_set_doc and get_show_doc functions.
2507 This improves how Parameter set/show documentation is processed
2508 and allows for more dynamic content.
2510 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2511 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2512 have an is_valid method.
2514 ** Breakpoints can now be sub-classed in Python, and in particular
2515 you may implement a 'stop' function that is executed each time
2516 the inferior reaches that breakpoint.
2518 ** New function gdb.lookup_global_symbol looks up a global symbol.
2520 ** GDB values in Python are now callable if the value represents a
2521 function. For example, if 'some_value' represents a function that
2522 takes two integer parameters and returns a value, you can call
2523 that function like so:
2525 result = some_value (10,20)
2527 ** Module gdb.types has been added.
2528 It contains a collection of utilities for working with gdb.Types objects:
2529 get_basic_type, has_field, make_enum_dict.
2531 ** Module gdb.printing has been added.
2532 It contains utilities for writing and registering pretty-printers.
2533 New classes: PrettyPrinter, SubPrettyPrinter,
2534 RegexpCollectionPrettyPrinter.
2535 New function: register_pretty_printer.
2537 ** New commands "info pretty-printers", "enable pretty-printer" and
2538 "disable pretty-printer" have been added.
2540 ** gdb.parameter("directories") is now available.
2542 ** New function gdb.newest_frame returns the newest frame in the
2545 ** The gdb.InferiorThread class has a new "name" attribute. This
2546 holds the thread's name.
2548 ** Python Support for Inferior events.
2549 Python scripts can add observers to be notified of events
2550 occurring in the process being debugged.
2551 The following events are currently supported:
2552 - gdb.events.cont Continue event.
2553 - gdb.events.exited Inferior exited event.
2554 - gdb.events.stop Signal received, and Breakpoint hit events.
2558 ** GDB now puts template parameters in scope when debugging in an
2559 instantiation. For example, if you have:
2561 template<int X> int func (void) { return X; }
2563 then if you step into func<5>, "print X" will show "5". This
2564 feature requires proper debuginfo support from the compiler; it
2565 was added to GCC 4.5.
2567 ** The motion commands "next", "finish", "until", and "advance" now
2568 work better when exceptions are thrown. In particular, GDB will
2569 no longer lose control of the inferior; instead, the GDB will
2570 stop the inferior at the point at which the exception is caught.
2571 This functionality requires a change in the exception handling
2572 code that was introduced in GCC 4.5.
2574 * GDB now follows GCC's rules on accessing volatile objects when
2575 reading or writing target state during expression evaluation.
2576 One notable difference to prior behavior is that "print x = 0"
2577 no longer generates a read of x; the value of the assignment is
2578 now always taken directly from the value being assigned.
2580 * GDB now has some support for using labels in the program's source in
2581 linespecs. For instance, you can use "advance label" to continue
2582 execution to a label.
2584 * GDB now has support for reading and writing a new .gdb_index
2585 section. This section holds a fast index of DWARF debugging
2586 information and can be used to greatly speed up GDB startup and
2587 operation. See the documentation for `save gdb-index' for details.
2589 * The "watch" command now accepts an optional "-location" argument.
2590 When used, this causes GDB to watch the memory referred to by the
2591 expression. Such a watchpoint is never deleted due to it going out
2594 * GDB now supports thread debugging of core dumps on GNU/Linux.
2596 GDB now activates thread debugging using the libthread_db library
2597 when debugging GNU/Linux core dumps, similarly to when debugging
2598 live processes. As a result, when debugging a core dump file, GDB
2599 is now able to display pthread_t ids of threads. For example, "info
2600 threads" shows the same output as when debugging the process when it
2601 was live. In earlier releases, you'd see something like this:
2604 * 1 LWP 6780 main () at main.c:10
2606 While now you see this:
2609 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2611 It is also now possible to inspect TLS variables when debugging core
2614 When debugging a core dump generated on a machine other than the one
2615 used to run GDB, you may need to point GDB at the correct
2616 libthread_db library with the "set libthread-db-search-path"
2617 command. See the user manual for more details on this command.
2619 * When natively debugging programs on PowerPC BookE processors running
2620 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2621 which stop execution of the inferior whenever it executes an instruction
2622 at any address within the specified range. See the "PowerPC Embedded"
2623 section in the user manual for more details.
2625 * New features in the GDB remote stub, GDBserver
2627 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2628 and i686 LynxOS (version 5.x).
2630 ** GDBserver is now supported on Blackfin Linux.
2632 * New native configurations
2634 ia64 HP-UX ia64-*-hpux*
2638 Analog Devices, Inc. Blackfin Processor bfin-*
2640 * Ada task switching is now supported on sparc-elf targets when
2641 debugging a program using the Ravenscar Profile. For more information,
2642 see the "Tasking Support when using the Ravenscar Profile" section
2643 in the GDB user manual.
2645 * Guile support was removed.
2647 * New features in the GNU simulator
2649 ** The --map-info flag lists all known core mappings.
2651 ** CFI flashes may be simulated via the "cfi" device.
2653 *** Changes in GDB 7.2
2655 * Shared library support for remote targets by default
2657 When GDB is configured for a generic, non-OS specific target, like
2658 for example, --target=arm-eabi or one of the many *-*-elf targets,
2659 GDB now queries remote stubs for loaded shared libraries using the
2660 `qXfer:libraries:read' packet. Previously, shared library support
2661 was always disabled for such configurations.
2665 ** Argument Dependent Lookup (ADL)
2667 In C++ ADL lookup directs function search to the namespaces of its
2668 arguments even if the namespace has not been imported.
2678 Here the compiler will search for `foo' in the namespace of 'b'
2679 and find A::foo. GDB now supports this. This construct is commonly
2680 used in the Standard Template Library for operators.
2682 ** Improved User Defined Operator Support
2684 In addition to member operators, GDB now supports lookup of operators
2685 defined in a namespace and imported with a `using' directive, operators
2686 defined in the global scope, operators imported implicitly from an
2687 anonymous namespace, and the ADL operators mentioned in the previous
2689 GDB now also supports proper overload resolution for all the previously
2690 mentioned flavors of operators.
2692 ** static const class members
2694 Printing of static const class members that are initialized in the
2695 class definition has been fixed.
2697 * Windows Thread Information Block access.
2699 On Windows targets, GDB now supports displaying the Windows Thread
2700 Information Block (TIB) structure. This structure is visible either
2701 by using the new command `info w32 thread-information-block' or, by
2702 dereferencing the new convenience variable named `$_tlb', a
2703 thread-specific pointer to the TIB. This feature is also supported
2704 when remote debugging using GDBserver.
2706 * Static tracepoints
2708 Static tracepoints are calls in the user program into a tracing
2709 library. One such library is a port of the LTTng kernel tracer to
2710 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2711 When debugging with GDBserver, GDB now supports combining the GDB
2712 tracepoint machinery with such libraries. For example: the user can
2713 use GDB to probe a static tracepoint marker (a call from the user
2714 program into the tracing library) with the new "strace" command (see
2715 "New commands" below). This creates a "static tracepoint" in the
2716 breakpoint list, that can be manipulated with the same feature set
2717 as fast and regular tracepoints. E.g., collect registers, local and
2718 global variables, collect trace state variables, and define
2719 tracepoint conditions. In addition, the user can collect extra
2720 static tracepoint marker specific data, by collecting the new
2721 $_sdata internal variable. When analyzing the trace buffer, you can
2722 inspect $_sdata like any other variable available to GDB. For more
2723 information, see the "Tracepoints" chapter in GDB user manual. New
2724 remote packets have been defined to support static tracepoints, see
2725 the "New remote packets" section below.
2727 * Better reconstruction of tracepoints after disconnected tracing
2729 GDB will attempt to download the original source form of tracepoint
2730 definitions when starting a trace run, and then will upload these
2731 upon reconnection to the target, resulting in a more accurate
2732 reconstruction of the tracepoints that are in use on the target.
2736 You can now exercise direct control over the ways that GDB can
2737 affect your program. For instance, you can disallow the setting of
2738 breakpoints, so that the program can run continuously (assuming
2739 non-stop mode). In addition, the "observer" variable is available
2740 to switch all of the different controls; in observer mode, GDB
2741 cannot affect the target's behavior at all, which is useful for
2742 tasks like diagnosing live systems in the field.
2744 * The new convenience variable $_thread holds the number of the
2747 * New remote packets
2751 Return the address of the Windows Thread Information Block of a given thread.
2755 In response to several of the tracepoint packets, the target may now
2756 also respond with a number of intermediate `qRelocInsn' request
2757 packets before the final result packet, to have GDB handle
2758 relocating an instruction to execute at a different address. This
2759 is particularly useful for stubs that support fast tracepoints. GDB
2760 reports support for this feature in the qSupported packet.
2764 List static tracepoint markers in the target program.
2768 List static tracepoint markers at a given address in the target
2771 qXfer:statictrace:read
2773 Read the static trace data collected (by a `collect $_sdata'
2774 tracepoint action). The remote stub reports support for this packet
2775 to gdb's qSupported query.
2779 Send the current settings of GDB's permission flags.
2783 Send part of the source (textual) form of a tracepoint definition,
2784 which includes location, conditional, and action list.
2786 * The source command now accepts a -s option to force searching for the
2787 script in the source search path even if the script name specifies
2790 * New features in the GDB remote stub, GDBserver
2792 - GDBserver now support tracepoints (including fast tracepoints, and
2793 static tracepoints). The feature is currently supported by the
2794 i386-linux and amd64-linux builds. See the "Tracepoints support
2795 in gdbserver" section in the manual for more information.
2797 GDBserver JIT compiles the tracepoint's conditional agent
2798 expression bytecode into native code whenever possible for low
2799 overhead dynamic tracepoints conditionals. For such tracepoints,
2800 an expression that examines program state is evaluated when the
2801 tracepoint is reached, in order to determine whether to capture
2802 trace data. If the condition is simple and false, processing the
2803 tracepoint finishes very quickly and no data is gathered.
2805 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2806 for static tracepoints support.
2808 - GDBserver now supports x86_64 Windows 64-bit debugging.
2810 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2811 it understands register description.
2813 * The --batch flag now disables pagination and queries.
2815 * X86 general purpose registers
2817 GDB now supports reading/writing byte, word and double-word x86
2818 general purpose registers directly. This means you can use, say,
2819 $ah or $ax to refer, respectively, to the byte register AH and
2820 16-bit word register AX that are actually portions of the 32-bit
2821 register EAX or 64-bit register RAX.
2823 * The `commands' command now accepts a range of breakpoints to modify.
2824 A plain `commands' following a command that creates multiple
2825 breakpoints affects all the breakpoints set by that command. This
2826 applies to breakpoints set by `rbreak', and also applies when a
2827 single `break' command creates multiple breakpoints (e.g.,
2828 breakpoints on overloaded c++ functions).
2830 * The `rbreak' command now accepts a filename specification as part of
2831 its argument, limiting the functions selected by the regex to those
2832 in the specified file.
2834 * Support for remote debugging Windows and SymbianOS shared libraries
2835 from Unix hosts has been improved. Non Windows GDB builds now can
2836 understand target reported file names that follow MS-DOS based file
2837 system semantics, such as file names that include drive letters and
2838 use the backslash character as directory separator. This makes it
2839 possible to transparently use the "set sysroot" and "set
2840 solib-search-path" on Unix hosts to point as host copies of the
2841 target's shared libraries. See the new command "set
2842 target-file-system-kind" described below, and the "Commands to
2843 specify files" section in the user manual for more information.
2847 eval template, expressions...
2848 Convert the values of one or more expressions under the control
2849 of the string template to a command line, and call it.
2851 set target-file-system-kind unix|dos-based|auto
2852 show target-file-system-kind
2853 Set or show the assumed file system kind for target reported file
2856 save breakpoints <filename>
2857 Save all current breakpoint definitions to a file suitable for use
2858 in a later debugging session. To read the saved breakpoint
2859 definitions, use the `source' command.
2861 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2864 info static-tracepoint-markers
2865 Display information about static tracepoint markers in the target.
2867 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2868 Define a static tracepoint by probing a marker at the given
2869 function, line, address, or marker ID.
2873 Enable and disable observer mode.
2875 set may-write-registers on|off
2876 set may-write-memory on|off
2877 set may-insert-breakpoints on|off
2878 set may-insert-tracepoints on|off
2879 set may-insert-fast-tracepoints on|off
2880 set may-interrupt on|off
2881 Set individual permissions for GDB effects on the target. Note that
2882 some of these settings can have undesirable or surprising
2883 consequences, particularly when changed in the middle of a session.
2884 For instance, disabling the writing of memory can prevent
2885 breakpoints from being inserted, cause single-stepping to fail, or
2886 even crash your program, if you disable after breakpoints have been
2887 inserted. However, GDB should not crash.
2889 set record memory-query on|off
2890 show record memory-query
2891 Control whether to stop the inferior if memory changes caused
2892 by an instruction cannot be recorded.
2897 The disassemble command now supports "start,+length" form of two arguments.
2901 ** GDB now provides a new directory location, called the python directory,
2902 where Python scripts written for GDB can be installed. The location
2903 of that directory is <data-directory>/python, where <data-directory>
2904 is the GDB data directory. For more details, see section `Scripting
2905 GDB using Python' in the manual.
2907 ** The GDB Python API now has access to breakpoints, symbols, symbol
2908 tables, program spaces, inferiors, threads and frame's code blocks.
2909 Additionally, GDB Parameters can now be created from the API, and
2910 manipulated via set/show in the CLI.
2912 ** New functions gdb.target_charset, gdb.target_wide_charset,
2913 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2915 ** New exception gdb.GdbError.
2917 ** Pretty-printers are now also looked up in the current program space.
2919 ** Pretty-printers can now be individually enabled and disabled.
2921 ** GDB now looks for names of Python scripts to auto-load in a
2922 special section named `.debug_gdb_scripts', in addition to looking
2923 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2925 * Tracepoint actions were unified with breakpoint commands. In particular,
2926 there are no longer differences in "info break" output for breakpoints and
2927 tracepoints and the "commands" command can be used for both tracepoints and
2928 regular breakpoints.
2932 ARM Symbian arm*-*-symbianelf*
2934 * D language support.
2935 GDB now supports debugging programs written in the D programming
2938 * GDB now supports the extended ptrace interface for PowerPC which is
2939 available since Linux kernel version 2.6.34. This automatically enables
2940 any hardware breakpoints and additional hardware watchpoints available in
2941 the processor. The old ptrace interface exposes just one hardware
2942 watchpoint and no hardware breakpoints.
2944 * GDB is now able to use the Data Value Compare (DVC) register available on
2945 embedded PowerPC processors to implement in hardware simple watchpoint
2946 conditions of the form:
2948 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2950 This works in native GDB running on Linux kernels with the extended ptrace
2951 interface mentioned above.
2953 *** Changes in GDB 7.1
2957 ** Namespace Support
2959 GDB now supports importing of namespaces in C++. This enables the
2960 user to inspect variables from imported namespaces. Support for
2961 namepace aliasing has also been added. So, if a namespace is
2962 aliased in the current scope (e.g. namepace C=A; ) the user can
2963 print variables using the alias (e.g. (gdb) print C::x).
2967 All known bugs relating to the printing of virtual base class were
2968 fixed. It is now possible to call overloaded static methods using a
2973 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2974 and reinterpret_cast<> are now handled by the C++ expression parser.
2978 Xilinx MicroBlaze microblaze-*-*
2983 Xilinx MicroBlaze microblaze
2986 * Multi-program debugging.
2988 GDB now has support for multi-program (a.k.a. multi-executable or
2989 multi-exec) debugging. This allows for debugging multiple inferiors
2990 simultaneously each running a different program under the same GDB
2991 session. See "Debugging Multiple Inferiors and Programs" in the
2992 manual for more information. This implied some user visible changes
2993 in the multi-inferior support. For example, "info inferiors" now
2994 lists inferiors that are not running yet or that have exited
2995 already. See also "New commands" and "New options" below.
2997 * New tracing features
2999 GDB's tracepoint facility now includes several new features:
3001 ** Trace state variables
3003 GDB tracepoints now include support for trace state variables, which
3004 are variables managed by the target agent during a tracing
3005 experiment. They are useful for tracepoints that trigger each
3006 other, so for instance one tracepoint can count hits in a variable,
3007 and then a second tracepoint has a condition that is true when the
3008 count reaches a particular value. Trace state variables share the
3009 $-syntax of GDB convenience variables, and can appear in both
3010 tracepoint actions and condition expressions. Use the "tvariable"
3011 command to create, and "info tvariables" to view; see "Trace State
3012 Variables" in the manual for more detail.
3016 GDB now includes an option for defining fast tracepoints, which
3017 targets may implement more efficiently, such as by installing a jump
3018 into the target agent rather than a trap instruction. The resulting
3019 speedup can be by two orders of magnitude or more, although the
3020 tradeoff is that some program locations on some target architectures
3021 might not allow fast tracepoint installation, for instance if the
3022 instruction to be replaced is shorter than the jump. To request a
3023 fast tracepoint, use the "ftrace" command, with syntax identical to
3024 the regular trace command.
3026 ** Disconnected tracing
3028 It is now possible to detach GDB from the target while it is running
3029 a trace experiment, then reconnect later to see how the experiment
3030 is going. In addition, a new variable disconnected-tracing lets you
3031 tell the target agent whether to continue running a trace if the
3032 connection is lost unexpectedly.
3036 GDB now has the ability to save the trace buffer into a file, and
3037 then use that file as a target, similarly to you can do with
3038 corefiles. You can select trace frames, print data that was
3039 collected in them, and use tstatus to display the state of the
3040 tracing run at the moment that it was saved. To create a trace
3041 file, use "tsave <filename>", and to use it, do "target tfile
3044 ** Circular trace buffer
3046 You can ask the target agent to handle the trace buffer as a
3047 circular buffer, discarding the oldest trace frames to make room for
3048 newer ones, by setting circular-trace-buffer to on. This feature may
3049 not be available for all target agents.
3054 The disassemble command, when invoked with two arguments, now requires
3055 the arguments to be comma-separated.
3058 The info variables command now displays variable definitions. Files
3059 which only declare a variable are not shown.
3062 The source command is now capable of sourcing Python scripts.
3063 This feature is dependent on the debugger being build with Python
3066 Related to this enhancement is also the introduction of a new command
3067 "set script-extension" (see below).
3069 * New commands (for set/show, see "New options" below)
3071 record save [<FILENAME>]
3072 Save a file (in core file format) containing the process record
3073 execution log for replay debugging at a later time.
3075 record restore <FILENAME>
3076 Restore the process record execution log that was saved at an
3077 earlier time, for replay debugging.
3079 add-inferior [-copies <N>] [-exec <FILENAME>]
3082 clone-inferior [-copies <N>] [ID]
3083 Make a new inferior ready to execute the same program another
3084 inferior has loaded.
3089 maint info program-spaces
3090 List the program spaces loaded into GDB.
3092 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3093 show remote interrupt-sequence
3094 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3095 as the sequence to the remote target in order to interrupt the execution.
3096 Ctrl-C is a default. Some system prefers BREAK which is high level of
3097 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3098 Magic SysRq g. It is BREAK signal and character 'g'.
3100 set remote interrupt-on-connect [on | off]
3101 show remote interrupt-on-connect
3102 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3103 remote target when gdb connects to it. This is needed when you debug
3106 set remotebreak [on | off]
3108 Deprecated. Use "set/show remote interrupt-sequence" instead.
3110 tvariable $NAME [ = EXP ]
3111 Create or modify a trace state variable.
3114 List trace state variables and their values.
3116 delete tvariable $NAME ...
3117 Delete one or more trace state variables.
3120 Evaluate the given expressions without collecting anything into the
3121 trace buffer. (Valid in tracepoint actions only.)
3123 ftrace FN / FILE:LINE / *ADDR
3124 Define a fast tracepoint at the given function, line, or address.
3126 * New expression syntax
3128 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3129 GDB now parses 0b101010 identically with 42.
3133 set follow-exec-mode new|same
3134 show follow-exec-mode
3135 Control whether GDB reuses the same inferior across an exec call or
3136 creates a new one. This is useful to be able to restart the old
3137 executable after the inferior having done an exec call.
3139 set default-collect EXPR, ...
3140 show default-collect
3141 Define a list of expressions to be collected at each tracepoint.
3142 This is a useful way to ensure essential items are not overlooked,
3143 such as registers or a critical global variable.
3145 set disconnected-tracing
3146 show disconnected-tracing
3147 If set to 1, the target is instructed to continue tracing if it
3148 loses its connection to GDB. If 0, the target is to stop tracing
3151 set circular-trace-buffer
3152 show circular-trace-buffer
3153 If set to on, the target is instructed to use a circular trace buffer
3154 and discard the oldest trace frames instead of stopping the trace due
3155 to a full trace buffer. If set to off, the trace stops when the buffer
3156 fills up. Some targets may not support this.
3158 set script-extension off|soft|strict
3159 show script-extension
3160 If set to "off", the debugger does not perform any script language
3161 recognition, and all sourced files are assumed to be GDB scripts.
3162 If set to "soft" (the default), files are sourced according to
3163 filename extension, falling back to GDB scripts if the first
3165 If set to "strict", files are sourced according to filename extension.
3167 set ada trust-PAD-over-XVS on|off
3168 show ada trust-PAD-over-XVS
3169 If off, activate a workaround against a bug in the debugging information
3170 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3171 the GCC sources for more information about the GNAT encoding and
3172 PAD types in particular). It is always safe to set this option to
3173 off, but this introduces a slight performance penalty. The default
3176 * Python API Improvements
3178 ** GDB provides the new class gdb.LazyString. This is useful in
3179 some pretty-printing cases. The new method gdb.Value.lazy_string
3180 provides a simple way to create objects of this type.
3182 ** The fields returned by gdb.Type.fields now have an
3183 `is_base_class' attribute.
3185 ** The new method gdb.Type.range returns the range of an array type.
3187 ** The new method gdb.parse_and_eval can be used to parse and
3188 evaluate an expression.
3190 * New remote packets
3193 Define a trace state variable.
3196 Get the current value of a trace state variable.
3199 Set desired tracing behavior upon disconnection.
3202 Set the trace buffer to be linear or circular.
3205 Get data about the tracepoints currently in use.
3209 Process record now works correctly with hardware watchpoints.
3211 Multiple bug fixes have been made to the mips-irix port, making it
3212 much more reliable. In particular:
3213 - Debugging threaded applications is now possible again. Previously,
3214 GDB would hang while starting the program, or while waiting for
3215 the program to stop at a breakpoint.
3216 - Attaching to a running process no longer hangs.
3217 - An error occurring while loading a core file has been fixed.
3218 - Changing the value of the PC register now works again. This fixes
3219 problems observed when using the "jump" command, or when calling
3220 a function from GDB, or even when assigning a new value to $pc.
3221 - With the "finish" and "return" commands, the return value for functions
3222 returning a small array is now correctly printed.
3223 - It is now possible to break on shared library code which gets executed
3224 during a shared library init phase (code executed while executing
3225 their .init section). Previously, the breakpoint would have no effect.
3226 - GDB is now able to backtrace through the signal handler for
3227 non-threaded programs.
3229 PIE (Position Independent Executable) programs debugging is now supported.
3230 This includes debugging execution of PIC (Position Independent Code) shared
3231 libraries although for that, it should be possible to run such libraries as an
3234 *** Changes in GDB 7.0
3236 * GDB now has an interface for JIT compilation. Applications that
3237 dynamically generate code can create symbol files in memory and register
3238 them with GDB. For users, the feature should work transparently, and
3239 for JIT developers, the interface is documented in the GDB manual in the
3240 "JIT Compilation Interface" chapter.
3242 * Tracepoints may now be conditional. The syntax is as for
3243 breakpoints; either an "if" clause appended to the "trace" command,
3244 or the "condition" command is available. GDB sends the condition to
3245 the target for evaluation using the same bytecode format as is used
3246 for tracepoint actions.
3248 * The disassemble command now supports: an optional /r modifier, print the
3249 raw instructions in hex as well as in symbolic form, and an optional /m
3250 modifier to print mixed source+assembly.
3252 * Process record and replay
3254 In a architecture environment that supports ``process record and
3255 replay'', ``process record and replay'' target can record a log of
3256 the process execution, and replay it with both forward and reverse
3259 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3260 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3261 set execution-direction {forward|reverse}, for targets that support
3264 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3265 feature is available with a native GDB running on kernel version
3268 * GDB now has support for multi-byte and wide character sets on the
3269 target. Strings whose character type is wchar_t, char16_t, or
3270 char32_t are now correctly printed. GDB supports wide- and unicode-
3271 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3272 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3273 `printf'. This feature requires iconv to work properly; if your
3274 system does not have a working iconv, GDB can use GNU libiconv. See
3275 the installation instructions for more information.
3277 * GDB now supports automatic retrieval of shared library files from
3278 remote targets. To use this feature, specify a system root that begins
3279 with the `remote:' prefix, either via the `set sysroot' command or via
3280 the `--with-sysroot' configure-time option.
3282 * "info sharedlibrary" now takes an optional regex of libraries to show,
3283 and it now reports if a shared library has no debugging information.
3285 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3286 now complete on file names.
3288 * When completing in expressions, gdb will attempt to limit
3289 completions to allowable structure or union fields, where appropriate.
3290 For instance, consider:
3292 # struct example { int f1; double f2; };
3293 # struct example variable;
3296 If the user types TAB at the end of this command line, the available
3297 completions will be "f1" and "f2".
3299 * Inlined functions are now supported. They show up in backtraces, and
3300 the "step", "next", and "finish" commands handle them automatically.
3302 * GDB now supports the token-splicing (##) and stringification (#)
3303 operators when expanding macros. It also supports variable-arity
3306 * GDB now supports inspecting extra signal information, exported by
3307 the new $_siginfo convenience variable. The feature is currently
3308 implemented on linux ARM, i386 and amd64.
3310 * GDB can now display the VFP floating point registers and NEON vector
3311 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3312 can provide these registers (requires Linux 2.6.30 or later). Remote
3313 and simulator targets may also provide them.
3315 * New remote packets
3318 Search memory for a sequence of bytes.
3321 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3322 operation over reliable transport links. Use of this packet is
3323 controlled by the `set remote noack-packet' command.
3326 Kill the process with the specified process ID. Use this in preference
3327 to `k' when multiprocess protocol extensions are supported.
3330 Obtains additional operating system information
3334 Read or write additional signal information.
3336 * Removed remote protocol undocumented extension
3338 An undocumented extension to the remote protocol's `S' stop reply
3339 packet that permited the stub to pass a process id was removed.
3340 Remote servers should use the `T' stop reply packet instead.
3342 * GDB now supports multiple function calling conventions according to the
3343 DWARF-2 DW_AT_calling_convention function attribute.
3345 * The SH target utilizes the aforementioned change to distinguish between gcc
3346 and Renesas calling convention. It also adds the new CLI commands
3347 `set/show sh calling-convention'.
3349 * GDB can now read compressed debug sections, as produced by GNU gold
3350 with the --compress-debug-sections=zlib flag.
3352 * 64-bit core files are now supported on AIX.
3354 * Thread switching is now supported on Tru64.
3356 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3357 which will be allocated using malloc later in program execution.
3359 * The qXfer:libraries:read remote procotol packet now allows passing a
3360 list of section offsets.
3362 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3363 conditions handling signals delivered during attach or thread creation
3364 have also been fixed.
3366 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3367 From the user's standpoint, all unqualified instances of True and False
3368 are treated as the standard definitions, regardless of context.
3370 * GDB now parses C++ symbol and type names more flexibly. For
3373 template<typename T> class C { };
3376 GDB will now correctly handle all of:
3378 ptype C<char const *>
3379 ptype C<char const*>
3380 ptype C<const char *>
3381 ptype C<const char*>
3383 * New features in the GDB remote stub, gdbserver
3385 - The "--wrapper" command-line argument tells gdbserver to use a
3386 wrapper program to launch programs for debugging.
3388 - On PowerPC and S/390 targets, it is now possible to use a single
3389 gdbserver executable to debug both 32-bit and 64-bit programs.
3390 (This requires gdbserver itself to be built as a 64-bit executable.)
3392 - gdbserver uses the new noack protocol mode for TCP connections to
3393 reduce communications latency, if also supported and enabled in GDB.
3395 - Support for the sparc64-linux-gnu target is now included in
3398 - The amd64-linux build of gdbserver now supports debugging both
3399 32-bit and 64-bit programs.
3401 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3402 now support hardware watchpoints, and will use them automatically
3407 GDB now has support for scripting using Python. Whether this is
3408 available is determined at configure time.
3410 New GDB commands can now be written in Python.
3412 * Ada tasking support
3414 Ada tasks can now be inspected in GDB. The following commands have
3418 Print the list of Ada tasks.
3420 Print detailed information about task number N.
3422 Print the task number of the current task.
3424 Switch the context of debugging to task number N.
3426 * Support for user-defined prefixed commands. The "define" command can
3427 add new commands to existing prefixes, e.g. "target".
3429 * Multi-inferior, multi-process debugging.
3431 GDB now has generalized support for multi-inferior debugging. See
3432 "Debugging Multiple Inferiors" in the manual for more information.
3433 Although availability still depends on target support, the command
3434 set is more uniform now. The GNU/Linux specific multi-forks support
3435 has been migrated to this new framework. This implied some user
3436 visible changes; see "New commands" and also "Removed commands"
3439 * Target descriptions can now describe the target OS ABI. See the
3440 "Target Description Format" section in the user manual for more
3443 * Target descriptions can now describe "compatible" architectures
3444 to indicate that the target can execute applications for a different
3445 architecture in addition to those for the main target architecture.
3446 See the "Target Description Format" section in the user manual for
3449 * Multi-architecture debugging.
3451 GDB now includes general supports for debugging applications on
3452 hybrid systems that use more than one single processor architecture
3453 at the same time. Each such hybrid architecture still requires
3454 specific support to be added. The only hybrid architecture supported
3455 in this version of GDB is the Cell Broadband Engine.
3457 * GDB now supports integrated debugging of Cell/B.E. applications that
3458 use both the PPU and SPU architectures. To enable support for hybrid
3459 Cell/B.E. debugging, you need to configure GDB to support both the
3460 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3461 --enable-targets configure option.
3463 * Non-stop mode debugging.
3465 For some targets, GDB now supports an optional mode of operation in
3466 which you can examine stopped threads while other threads continue
3467 to execute freely. This is referred to as non-stop mode, with the
3468 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3469 section in the user manual for more information.
3471 To be able to support remote non-stop debugging, a remote stub needs
3472 to implement the non-stop mode remote protocol extensions, as
3473 described in the "Remote Non-Stop" section of the user manual. The
3474 GDB remote stub, gdbserver, has been adjusted to support these
3475 extensions on linux targets.
3477 * New commands (for set/show, see "New options" below)
3479 catch syscall [NAME(S) | NUMBER(S)]
3480 Catch system calls. Arguments, which should be names of system
3481 calls or their numbers, mean catch only those syscalls. Without
3482 arguments, every syscall will be caught. When the inferior issues
3483 any of the specified syscalls, GDB will stop and announce the system
3484 call, both when it is called and when its call returns. This
3485 feature is currently available with a native GDB running on the
3486 Linux Kernel, under the following architectures: x86, x86_64,
3487 PowerPC and PowerPC64.
3489 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3491 Search memory for a sequence of bytes.
3493 maint set python print-stack
3494 maint show python print-stack
3495 Show a stack trace when an error is encountered in a Python script.
3498 Invoke CODE by passing it to the Python interpreter.
3503 These allow macros to be defined, undefined, and listed
3507 Show operating system information about processes.
3510 List the inferiors currently under GDB's control.
3513 Switch focus to inferior number NUM.
3516 Detach from inferior number NUM.
3519 Kill inferior number NUM.
3523 set spu stop-on-load
3524 show spu stop-on-load
3525 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3527 set spu auto-flush-cache
3528 show spu auto-flush-cache
3529 Control whether to automatically flush the software-managed cache
3530 during Cell/B.E. debugging.
3532 set sh calling-convention
3533 show sh calling-convention
3534 Control the calling convention used when calling SH target functions.
3537 show debug timestamp
3538 Control display of timestamps with GDB debugging output.
3540 set disassemble-next-line
3541 show disassemble-next-line
3542 Control display of disassembled source lines or instructions when
3545 set remote noack-packet
3546 show remote noack-packet
3547 Set/show the use of remote protocol QStartNoAckMode packet. See above
3548 under "New remote packets."
3550 set remote query-attached-packet
3551 show remote query-attached-packet
3552 Control use of remote protocol `qAttached' (query-attached) packet.
3554 set remote read-siginfo-object
3555 show remote read-siginfo-object
3556 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3559 set remote write-siginfo-object
3560 show remote write-siginfo-object
3561 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3564 set remote reverse-continue
3565 show remote reverse-continue
3566 Control use of remote protocol 'bc' (reverse-continue) packet.
3568 set remote reverse-step
3569 show remote reverse-step
3570 Control use of remote protocol 'bs' (reverse-step) packet.
3572 set displaced-stepping
3573 show displaced-stepping
3574 Control displaced stepping mode. Displaced stepping is a way to
3575 single-step over breakpoints without removing them from the debuggee.
3576 Also known as "out-of-line single-stepping".
3579 show debug displaced
3580 Control display of debugging info for displaced stepping.
3582 maint set internal-error
3583 maint show internal-error
3584 Control what GDB does when an internal error is detected.
3586 maint set internal-warning
3587 maint show internal-warning
3588 Control what GDB does when an internal warning is detected.
3593 Use a wrapper program to launch programs for debugging.
3595 set multiple-symbols (all|ask|cancel)
3596 show multiple-symbols
3597 The value of this variable can be changed to adjust the debugger behavior
3598 when an expression or a breakpoint location contains an ambiguous symbol
3599 name (an overloaded function name, for instance).
3601 set breakpoint always-inserted
3602 show breakpoint always-inserted
3603 Keep breakpoints always inserted in the target, as opposed to inserting
3604 them when resuming the target, and removing them when the target stops.
3605 This option can improve debugger performance on slow remote targets.
3607 set arm fallback-mode (arm|thumb|auto)
3608 show arm fallback-mode
3609 set arm force-mode (arm|thumb|auto)
3611 These commands control how ARM GDB determines whether instructions
3612 are ARM or Thumb. The default for both settings is auto, which uses
3613 the current CPSR value for instructions without symbols; previous
3614 versions of GDB behaved as if "set arm fallback-mode arm".
3616 set disable-randomization
3617 show disable-randomization
3618 Standalone programs run with the virtual address space randomization enabled
3619 by default on some platforms. This option keeps the addresses stable across
3620 multiple debugging sessions.
3624 Control whether other threads are stopped or not when some thread hits
3629 Requests that asynchronous execution is enabled in the target, if available.
3630 In this case, it's possible to resume target in the background, and interact
3631 with GDB while the target is running. "show target-async" displays the
3632 current state of asynchronous execution of the target.
3634 set target-wide-charset
3635 show target-wide-charset
3636 The target-wide-charset is the name of the character set that GDB
3637 uses when printing characters whose type is wchar_t.
3639 set tcp auto-retry (on|off)
3641 set tcp connect-timeout
3642 show tcp connect-timeout
3643 These commands allow GDB to retry failed TCP connections to a remote stub
3644 with a specified timeout period; this is useful if the stub is launched
3645 in parallel with GDB but may not be ready to accept connections immediately.
3647 set libthread-db-search-path
3648 show libthread-db-search-path
3649 Control list of directories which GDB will search for appropriate
3652 set schedule-multiple (on|off)
3653 show schedule-multiple
3654 Allow GDB to resume all threads of all processes or only threads of
3655 the current process.
3659 Use more aggressive caching for accesses to the stack. This improves
3660 performance of remote debugging (particularly backtraces) without
3661 affecting correctness.
3663 set interactive-mode (on|off|auto)
3664 show interactive-mode
3665 Control whether GDB runs in interactive mode (on) or not (off).
3666 When in interactive mode, GDB waits for the user to answer all
3667 queries. Otherwise, GDB does not wait and assumes the default
3668 answer. When set to auto (the default), GDB determines which
3669 mode to use based on the stdin settings.
3674 For program forks, this is replaced by the new more generic `info
3675 inferiors' command. To list checkpoints, you can still use the
3676 `info checkpoints' command, which was an alias for the `info forks'
3680 Replaced by the new `inferior' command. To switch between
3681 checkpoints, you can still use the `restart' command, which was an
3682 alias for the `fork' command.
3685 This is removed, since some targets don't have a notion of
3686 processes. To switch between processes, you can still use the
3687 `inferior' command using GDB's own inferior number.
3690 For program forks, this is replaced by the new more generic `kill
3691 inferior' command. To delete a checkpoint, you can still use the
3692 `delete checkpoint' command, which was an alias for the `delete
3696 For program forks, this is replaced by the new more generic `detach
3697 inferior' command. To detach a checkpoint, you can still use the
3698 `detach checkpoint' command, which was an alias for the `detach
3701 * New native configurations
3703 x86/x86_64 Darwin i[34567]86-*-darwin*
3705 x86_64 MinGW x86_64-*-mingw*
3709 Lattice Mico32 lm32-*
3710 x86 DICOS i[34567]86-*-dicos*
3711 x86_64 DICOS x86_64-*-dicos*
3714 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3715 (mingw32ce) debugging.
3721 These commands were actually not implemented on any target.
3723 *** Changes in GDB 6.8
3725 * New native configurations
3727 NetBSD/hppa hppa*-*netbsd*
3728 Xtensa GNU/Linux xtensa*-*-linux*
3732 NetBSD/hppa hppa*-*-netbsd*
3733 Xtensa GNU/Lunux xtensa*-*-linux*
3735 * Change in command line behavior -- corefiles vs. process ids.
3737 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3738 attaching to process NUMBER fails, GDB no longer attempts to open a
3739 core file named NUMBER. Attaching to a program using the -c option
3740 is no longer supported. Instead, use the '-p' or '--pid' options.
3742 * GDB can now be built as a native debugger for debugging Windows x86
3743 (mingw32) Portable Executable (PE) programs.
3745 * Pending breakpoints no longer change their number when their address
3748 * GDB now supports breakpoints with multiple locations,
3749 including breakpoints on C++ constructors, inside C++ templates,
3750 and in inlined functions.
3752 * GDB's ability to debug optimized code has been improved. GDB more
3753 accurately identifies function bodies and lexical blocks that occupy
3754 more than one contiguous range of addresses.
3756 * Target descriptions can now describe registers for PowerPC.
3758 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3759 registers on PowerPC targets.
3761 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3762 targets even when the libthread_db library is not available.
3764 * The GDB remote stub, gdbserver, now supports the new file transfer
3765 commands (remote put, remote get, and remote delete).
3767 * The GDB remote stub, gdbserver, now supports run and attach in
3768 extended-remote mode.
3770 * hppa*64*-*-hpux11* target broken
3771 The debugger is unable to start a program and fails with the following
3772 error: "Error trying to get information about dynamic linker".
3773 The gdb-6.7 release is also affected.
3775 * GDB now supports the --enable-targets= configure option to allow
3776 building a single GDB executable that supports multiple remote
3777 target architectures.
3779 * GDB now supports debugging C and C++ programs which use the
3780 Decimal Floating Point extension. In addition, the PowerPC target
3781 now has a set of pseudo-registers to inspect decimal float values
3782 stored in two consecutive float registers.
3784 * The -break-insert MI command can optionally create pending
3787 * Improved support for debugging Ada
3788 Many improvements to the Ada language support have been made. These
3790 - Better support for Ada2005 interface types
3791 - Improved handling of arrays and slices in general
3792 - Better support for Taft-amendment types
3793 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3795 - Improved command completion in Ada
3798 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3803 set print frame-arguments (all|scalars|none)
3804 show print frame-arguments
3805 The value of this variable can be changed to control which argument
3806 values should be printed by the debugger when displaying a frame.
3811 Transfer files to and from a remote target, and delete remote files.
3818 Transfer files to and from a remote target, and delete remote files.
3820 * New remote packets
3827 Open, close, read, write, and delete files on the remote system.
3830 Attach to an existing process on the remote system, in extended-remote
3834 Run a new process on the remote system, in extended-remote mode.
3836 *** Changes in GDB 6.7
3838 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3839 bfd, libiberty and opcodes, as revealed by static analysis donated by
3840 Coverity, Inc. (http://scan.coverity.com).
3842 * When looking up multiply-defined global symbols, GDB will now prefer the
3843 symbol definition in the current shared library if it was built using the
3844 -Bsymbolic linker option.
3846 * When the Text User Interface (TUI) is not configured, GDB will now
3847 recognize the -tui command-line option and print a message that the TUI
3850 * The GDB remote stub, gdbserver, now has lower overhead for high
3851 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3853 * GDB for MIPS targets now autodetects whether a remote target provides
3854 32-bit or 64-bit register values.
3856 * Support for C++ member pointers has been improved.
3858 * GDB now understands XML target descriptions, which specify the
3859 target's overall architecture. GDB can read a description from
3860 a local file or over the remote serial protocol.
3862 * Vectors of single-byte data use a new integer type which is not
3863 automatically displayed as character or string data.
3865 * The /s format now works with the print command. It displays
3866 arrays of single-byte integers and pointers to single-byte integers
3869 * Target descriptions can now describe target-specific registers,
3870 for architectures which have implemented the support (currently
3871 only ARM, M68K, and MIPS).
3873 * GDB and the GDB remote stub, gdbserver, now support the XScale
3876 * The GDB remote stub, gdbserver, has been updated to support
3877 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3878 has been rewritten to use the standard GDB remote protocol.
3880 * GDB can now step into C++ functions which are called through thunks.
3882 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3884 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3885 layout. It also supports a TextSeg= and DataSeg= response when only
3886 segment base addresses (rather than offsets) are available.
3888 * The /i format now outputs any trailing branch delay slot instructions
3889 immediately following the last instruction within the count specified.
3891 * The GDB remote protocol "T" stop reply packet now supports a
3892 "library" response. Combined with the new "qXfer:libraries:read"
3893 packet, this response allows GDB to debug shared libraries on targets
3894 where the operating system manages the list of loaded libraries (e.g.
3895 Windows and SymbianOS).
3897 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3898 (DLLs) on Windows and Windows CE targets.
3900 * GDB now supports a faster verification that a .debug file matches its binary
3901 according to its build-id signature, if the signature is present.
3907 Enable or disable hardware flow control (RTS/CTS) on the serial port
3908 when debugging using remote targets.
3910 set mem inaccessible-by-default
3911 show mem inaccessible-by-default
3912 If the target supplies a memory map, for instance via the remote
3913 protocol's "qXfer:memory-map:read" packet, setting this variable
3914 prevents GDB from accessing memory outside the memory map. This
3915 is useful for targets with memory mapped registers or which react
3916 badly to accesses of unmapped address space.
3918 set breakpoint auto-hw
3919 show breakpoint auto-hw
3920 If the target supplies a memory map, for instance via the remote
3921 protocol's "qXfer:memory-map:read" packet, setting this variable
3922 lets GDB use hardware breakpoints automatically for memory regions
3923 where it can not use software breakpoints. This covers both the
3924 "break" command and internal breakpoints used for other commands
3925 including "next" and "finish".
3928 catch exception unhandled
3929 Stop the program execution when Ada exceptions are raised.
3932 Stop the program execution when an Ada assertion failed.
3936 Set an alternate system root for target files. This is a more
3937 general version of "set solib-absolute-prefix", which is now
3938 an alias to "set sysroot".
3941 Provide extended SPU facility status information. This set of
3942 commands is available only when debugging the Cell/B.E. SPU
3945 * New native configurations
3947 OpenBSD/sh sh*-*openbsd*
3950 unset tdesc filename
3952 Use the specified local file as an XML target description, and do
3953 not query the target for its built-in description.
3957 OpenBSD/sh sh*-*-openbsd*
3958 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3959 Toshiba Media Processor mep-elf
3961 * New remote packets
3964 Ignore the specified signals; pass them directly to the debugged program
3965 without stopping other threads or reporting them to GDB.
3967 qXfer:features:read:
3968 Read an XML target description from the target, which describes its
3973 Read or write contents of an spufs file on the target system. These
3974 packets are available only on the Cell/B.E. SPU architecture.
3976 qXfer:libraries:read:
3977 Report the loaded shared libraries. Combined with new "T" packet
3978 response, this packet allows GDB to debug shared libraries on
3979 targets where the operating system manages the list of loaded
3980 libraries (e.g. Windows and SymbianOS).
3984 Support for these obsolete configurations has been removed.
3992 i[34567]86-*-lynxos*
3993 i[34567]86-*-netware*
3994 i[34567]86-*-sco3.2v5*
3995 i[34567]86-*-sco3.2v4*
3997 i[34567]86-*-sysv4.2*
4000 i[34567]86-*-unixware2*
4001 i[34567]86-*-unixware*
4010 * Other removed features
4017 Various m68k-only ROM monitors.
4024 Various Renesas ROM monitors and debugging interfaces for SH and
4029 Support for a Macraigor serial interface to on-chip debugging.
4030 GDB does not directly support the newer parallel or USB
4035 A debug information format. The predecessor to DWARF 2 and
4036 DWARF 3, which are still supported.
4038 Support for the HP aCC compiler on HP-UX/PA-RISC
4040 SOM-encapsulated symbolic debugging information, automatic
4041 invocation of pxdb, and the aCC custom C++ ABI. This does not
4042 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4043 with aCC can still be debugged on an assembly level.
4045 MIPS ".pdr" sections
4047 A MIPS-specific format used to describe stack frame layout
4048 in debugging information.
4052 GDB could work with an older version of Guile to debug
4053 the interpreter and Scheme programs running in it.
4055 set mips stack-arg-size
4056 set mips saved-gpreg-size
4058 Use "set mips abi" to control parameter passing for MIPS.
4060 *** Changes in GDB 6.6
4065 Cell Broadband Engine SPU spu-elf
4067 * GDB can now be configured as a cross-debugger targeting native Windows
4068 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4069 running on a Windows system over TCP/IP to debug Windows programs.
4071 * The GDB remote stub, gdbserver, has been updated to support Windows and
4072 Cygwin debugging. Both single-threaded and multi-threaded programs are
4075 * The "set trust-readonly-sections" command works again. This command was
4076 broken in GDB 6.3, 6.4, and 6.5.
4078 * The "load" command now supports writing to flash memory, if the remote
4079 stub provides the required support.
4081 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4082 longer requires symbolic debug information (e.g. DWARF-2).
4087 unset substitute-path
4088 show substitute-path
4089 Manage a list of substitution rules that GDB uses to rewrite the name
4090 of the directories where the sources are located. This can be useful
4091 for instance when the sources were moved to a different location
4092 between compilation and debugging.
4096 Print each CLI command as it is executed. Each command is prefixed with
4097 a number of `+' symbols representing the nesting depth.
4098 The source command now has a `-v' option to enable the same feature.
4102 The ARM Demon monitor support (RDP protocol, "target rdp").
4104 Kernel Object Display, an embedded debugging feature which only worked with
4105 an obsolete version of Cisco IOS.
4107 The 'set download-write-size' and 'show download-write-size' commands.
4109 * New remote packets
4112 Tell a stub about GDB client features, and request remote target features.
4113 The first feature implemented is PacketSize, which allows the target to
4114 specify the size of packets it can handle - to minimize the number of
4115 packets required and improve performance when connected to a remote
4119 Fetch an OS auxilliary vector from the remote stub. This packet is a
4120 more efficient replacement for qPart:auxv:read.
4122 qXfer:memory-map:read:
4123 Fetch a memory map from the remote stub, including information about
4124 RAM, ROM, and flash memory devices.
4129 Erase and program a flash memory device.
4131 * Removed remote packets
4134 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4135 used it, and only gdbserver implemented it.
4137 *** Changes in GDB 6.5
4141 Renesas M32C/M16C m32c-elf
4143 Morpho Technologies ms1 ms1-elf
4147 init-if-undefined Initialize a convenience variable, but
4148 only if it doesn't already have a value.
4150 The following commands are presently only implemented for native GNU/Linux:
4152 checkpoint Save a snapshot of the program state.
4154 restart <n> Return the program state to a
4155 previously saved state.
4157 info checkpoints List currently saved checkpoints.
4159 delete-checkpoint <n> Delete a previously saved checkpoint.
4161 set|show detach-on-fork Tell gdb whether to detach from a newly
4162 forked process, or to keep debugging it.
4164 info forks List forks of the user program that
4165 are available to be debugged.
4167 fork <n> Switch to debugging one of several
4168 forks of the user program that are
4169 available to be debugged.
4171 delete-fork <n> Delete a fork from the list of forks
4172 that are available to be debugged (and
4173 kill the forked process).
4175 detach-fork <n> Delete a fork from the list of forks
4176 that are available to be debugged (and
4177 allow the process to continue).
4181 Morpho Technologies ms2 ms1-elf
4183 * Improved Windows host support
4185 GDB now builds as a cross debugger hosted on i686-mingw32, including
4186 native console support, and remote communications using either
4187 network sockets or serial ports.
4189 * Improved Modula-2 language support
4191 GDB can now print most types in the Modula-2 syntax. This includes:
4192 basic types, set types, record types, enumerated types, range types,
4193 pointer types and ARRAY types. Procedure var parameters are correctly
4194 printed and hexadecimal addresses and character constants are also
4195 written in the Modula-2 syntax. Best results can be obtained by using
4196 GNU Modula-2 together with the -gdwarf-2 command line option.
4200 The ARM rdi-share module.
4202 The Netware NLM debug server.
4204 *** Changes in GDB 6.4
4206 * New native configurations
4208 OpenBSD/arm arm*-*-openbsd*
4209 OpenBSD/mips64 mips64-*-openbsd*
4213 Morpho Technologies ms1 ms1-elf
4215 * New command line options
4217 --batch-silent As for --batch, but totally silent.
4218 --return-child-result The debugger will exist with the same value
4219 the child (debugged) program exited with.
4220 --eval-command COMMAND, -ex COMMAND
4221 Execute a single GDB CLI command. This may be
4222 specified multiple times and in conjunction
4223 with the --command (-x) option.
4225 * Deprecated commands removed
4227 The following commands, that were deprecated in 2000, have been
4231 set|show arm disassembly-flavor set|show arm disassembler
4232 othernames set arm disassembler
4233 set|show remotedebug set|show debug remote
4234 set|show archdebug set|show debug arch
4235 set|show eventdebug set|show debug event
4238 * New BSD user-level threads support
4240 It is now possible to debug programs using the user-level threads
4241 library on OpenBSD and FreeBSD. Currently supported (target)
4244 FreeBSD/amd64 x86_64-*-freebsd*
4245 FreeBSD/i386 i386-*-freebsd*
4246 OpenBSD/i386 i386-*-openbsd*
4248 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4249 are not yet supported.
4251 * New support for Matsushita MN10300 w/sim added
4252 (Work in progress). mn10300-elf.
4254 * REMOVED configurations and files
4256 VxWorks and the XDR protocol *-*-vxworks
4257 Motorola MCORE mcore-*-*
4258 National Semiconductor NS32000 ns32k-*-*
4260 * New "set print array-indexes" command
4262 After turning this setting "on", GDB prints the index of each element
4263 when displaying arrays. The default is "off" to preserve the previous
4266 * VAX floating point support
4268 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4270 * User-defined command support
4272 In addition to using $arg0..$arg9 for argument passing, it is now possible
4273 to use $argc to determine now many arguments have been passed. See the
4274 section on user-defined commands in the user manual for more information.
4276 *** Changes in GDB 6.3:
4278 * New command line option
4280 GDB now accepts -l followed by a number to set the timeout for remote
4283 * GDB works with GCC -feliminate-dwarf2-dups
4285 GDB now supports a more compact representation of DWARF-2 debug
4286 information using DW_FORM_ref_addr references. These are produced
4287 by GCC with the option -feliminate-dwarf2-dups and also by some
4288 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4289 to use -feliminate-dwarf2-dups.
4291 * Internationalization
4293 When supported by the host system, GDB will be built with
4294 internationalization (libintl). The task of marking up the sources is
4295 continued, we're looking forward to our first translation.
4299 Initial support for debugging programs compiled with the GNAT
4300 implementation of the Ada programming language has been integrated
4301 into GDB. In this release, support is limited to expression evaluation.
4303 * New native configurations
4305 GNU/Linux/m32r m32r-*-linux-gnu
4309 GDB's remote protocol now includes support for the 'p' packet. This
4310 packet is used to fetch individual registers from a remote inferior.
4312 * END-OF-LIFE registers[] compatibility module
4314 GDB's internal register infrastructure has been completely rewritten.
4315 The new infrastructure making possible the implementation of key new
4316 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4319 GDB 6.3 will be the last release to include the the registers[]
4320 compatibility module that allowed out-of-date configurations to
4321 continue to work. This change directly impacts the following
4331 powerpc bdm protocol
4333 Unless there is activity to revive these configurations, they will be
4334 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4336 * OBSOLETE configurations and files
4338 Configurations that have been declared obsolete in this release have
4339 been commented out. Unless there is activity to revive these
4340 configurations, the next release of GDB will have their sources
4341 permanently REMOVED.
4350 *** Changes in GDB 6.2.1:
4352 * MIPS `break main; run' gave an heuristic-fence-post warning
4354 When attempting to run even a simple program, a warning about
4355 heuristic-fence-post being hit would be reported. This problem has
4358 * MIPS IRIX 'long double' crashed GDB
4360 When examining a long double variable, GDB would get a segmentation
4361 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4362 IRIX long double values).
4366 A bug in the VAX stack code was causing problems with the "next"
4367 command. This problem has been fixed.
4369 *** Changes in GDB 6.2:
4371 * Fix for ``many threads''
4373 On GNU/Linux systems that use the NPTL threads library, a program
4374 rapidly creating and deleting threads would confuse GDB leading to the
4377 ptrace: No such process.
4378 thread_db_get_info: cannot get thread info: generic error
4380 This problem has been fixed.
4382 * "-async" and "-noasync" options removed.
4384 Support for the broken "-noasync" option has been removed (it caused
4387 * New ``start'' command.
4389 This command runs the program until the begining of the main procedure.
4391 * New BSD Kernel Data Access Library (libkvm) interface
4393 Using ``target kvm'' it is now possible to debug kernel core dumps and
4394 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4395 platforms. Currently supported (native-only) configurations are:
4397 FreeBSD/amd64 x86_64-*-freebsd*
4398 FreeBSD/i386 i?86-*-freebsd*
4399 NetBSD/i386 i?86-*-netbsd*
4400 NetBSD/m68k m68*-*-netbsd*
4401 NetBSD/sparc sparc-*-netbsd*
4402 OpenBSD/amd64 x86_64-*-openbsd*
4403 OpenBSD/i386 i?86-*-openbsd*
4404 OpenBSD/m68k m68*-openbsd*
4405 OpenBSD/sparc sparc-*-openbsd*
4407 * Signal trampoline code overhauled
4409 Many generic problems with GDB's signal handling code have been fixed.
4410 These include: backtraces through non-contiguous stacks; recognition
4411 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4412 call; backtrace through a signal trampoline; step into and out of
4413 signal handlers; and single-stepping in the signal trampoline.
4415 Please note that kernel bugs are a limiting factor here. These
4416 features have been shown to work on an s390 GNU/Linux system that
4417 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4419 * Cygwin support for DWARF 2 added.
4421 * New native configurations
4423 GNU/Linux/hppa hppa*-*-linux*
4424 OpenBSD/hppa hppa*-*-openbsd*
4425 OpenBSD/m68k m68*-*-openbsd*
4426 OpenBSD/m88k m88*-*-openbsd*
4427 OpenBSD/powerpc powerpc-*-openbsd*
4428 NetBSD/vax vax-*-netbsd*
4429 OpenBSD/vax vax-*-openbsd*
4431 * END-OF-LIFE frame compatibility module
4433 GDB's internal frame infrastructure has been completely rewritten.
4434 The new infrastructure making it possible to support key new features
4435 including DWARF 2 Call Frame Information. To aid in the task of
4436 migrating old configurations to this new infrastructure, a
4437 compatibility module, that allowed old configurations to continue to
4438 work, was also included.
4440 GDB 6.2 will be the last release to include this frame compatibility
4441 module. This change directly impacts the following configurations:
4451 Unless there is activity to revive these configurations, they will be
4452 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4454 * REMOVED configurations and files
4456 Sun 3, running SunOS 3 m68*-*-sunos3*
4457 Sun 3, running SunOS 4 m68*-*-sunos4*
4458 Sun 2, running SunOS 3 m68000-*-sunos3*
4459 Sun 2, running SunOS 4 m68000-*-sunos4*
4460 Motorola 680x0 running LynxOS m68*-*-lynxos*
4461 AT&T 3b1/Unix pc m68*-att-*
4462 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4463 decstation mips-dec-* mips-little-*
4464 riscos mips-*-riscos* mips-*-sysv*
4465 sonymips mips-sony-*
4466 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4468 *** Changes in GDB 6.1.1:
4470 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4472 The TUI (Text-mode User Interface) is now built as part of a default
4473 GDB configuration. It is enabled by either selecting the TUI with the
4474 command line option "-i=tui" or by running the separate "gdbtui"
4475 program. For more information on the TUI, see the manual "Debugging
4478 * Pending breakpoint support (also included in GDB 6.1)
4480 Support has been added to allow you to specify breakpoints in shared
4481 libraries that have not yet been loaded. If a breakpoint location
4482 cannot be found, and the "breakpoint pending" option is set to auto,
4483 GDB queries you if you wish to make the breakpoint pending on a future
4484 shared-library load. If and when GDB resolves the breakpoint symbol,
4485 the pending breakpoint is removed as one or more regular breakpoints
4488 Pending breakpoints are very useful for GCJ Java debugging.
4490 * Fixed ISO-C build problems
4492 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4493 non ISO-C code that stopped them being built using a more strict ISO-C
4494 compiler (e.g., IBM's C compiler).
4496 * Fixed build problem on IRIX 5
4498 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4499 wasn't able to compile compile on an IRIX 5 system.
4501 * Added execute permission to gdb/gdbserver/configure
4503 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4504 permission. This bug would cause configure to fail on a number of
4505 systems (Solaris, IRIX). Ref: server/519.
4507 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4509 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4510 has been updated to use constant array sizes.
4512 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4514 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4515 its generated DWARF Call Frame Info. This encoding was causing GDB to
4516 panic, that panic has been fixed. Ref: gdb/1628.
4518 * Fixed a problem when examining parameters in shared library code.
4520 When examining parameters in optimized shared library code generated
4521 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4522 not available''. GDB now correctly displays the variable's value.
4524 *** Changes in GDB 6.1:
4526 * Removed --with-mmalloc
4528 Support for the mmalloc memory manager has been removed, as it
4529 conflicted with the internal gdb byte cache.
4531 * Changes in AMD64 configurations
4533 The AMD64 target now includes the %cs and %ss registers. As a result
4534 the AMD64 remote protocol has changed; this affects the floating-point
4535 and SSE registers. If you rely on those registers for your debugging,
4536 you should upgrade gdbserver on the remote side.
4538 * Revised SPARC target
4540 The SPARC target has been completely revised, incorporating the
4541 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4542 support for LynxOS and SunOS 4 has been dropped. Calling functions
4543 from within GDB on operating systems with a non-executable stack
4544 (Solaris, OpenBSD) now works.
4548 GDB has a new C++ demangler which does a better job on the mangled
4549 names generated by current versions of g++. It also runs faster, so
4550 with this and other changes gdb should now start faster on large C++
4553 * DWARF 2 Location Expressions
4555 GDB support for location expressions has been extended to support function
4556 arguments and frame bases. Older versions of GDB could crash when they
4559 * C++ nested types and namespaces
4561 GDB's support for nested types and namespaces in C++ has been
4562 improved, especially if you use the DWARF 2 debugging format. (This
4563 is the default for recent versions of GCC on most platforms.)
4564 Specifically, if you have a class "Inner" defined within a class or
4565 namespace "Outer", then GDB realizes that the class's name is
4566 "Outer::Inner", not simply "Inner". This should greatly reduce the
4567 frequency of complaints about not finding RTTI symbols. In addition,
4568 if you are stopped at inside of a function defined within a namespace,
4569 GDB modifies its name lookup accordingly.
4571 * New native configurations
4573 NetBSD/amd64 x86_64-*-netbsd*
4574 OpenBSD/amd64 x86_64-*-openbsd*
4575 OpenBSD/alpha alpha*-*-openbsd*
4576 OpenBSD/sparc sparc-*-openbsd*
4577 OpenBSD/sparc64 sparc64-*-openbsd*
4579 * New debugging protocols
4581 M32R with SDI protocol m32r-*-elf*
4583 * "set prompt-escape-char" command deleted.
4585 The command "set prompt-escape-char" has been deleted. This command,
4586 and its very obscure effet on GDB's prompt, was never documented,
4587 tested, nor mentioned in the NEWS file.
4589 * OBSOLETE configurations and files
4591 Configurations that have been declared obsolete in this release have
4592 been commented out. Unless there is activity to revive these
4593 configurations, the next release of GDB will have their sources
4594 permanently REMOVED.
4596 Sun 3, running SunOS 3 m68*-*-sunos3*
4597 Sun 3, running SunOS 4 m68*-*-sunos4*
4598 Sun 2, running SunOS 3 m68000-*-sunos3*
4599 Sun 2, running SunOS 4 m68000-*-sunos4*
4600 Motorola 680x0 running LynxOS m68*-*-lynxos*
4601 AT&T 3b1/Unix pc m68*-att-*
4602 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4603 decstation mips-dec-* mips-little-*
4604 riscos mips-*-riscos* mips-*-sysv*
4605 sonymips mips-sony-*
4606 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4608 * REMOVED configurations and files
4610 SGI Irix-4.x mips-sgi-irix4 or iris4
4611 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4612 Z8000 simulator z8k-zilog-none or z8ksim
4613 Matsushita MN10200 w/simulator mn10200-*-*
4614 H8/500 simulator h8500-hitachi-hms or h8500hms
4615 HP/PA running BSD hppa*-*-bsd*
4616 HP/PA running OSF/1 hppa*-*-osf*
4617 HP/PA Pro target hppa*-*-pro*
4618 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4619 386BSD i[3456]86-*-bsd*
4620 Sequent family i[3456]86-sequent-sysv4*
4621 i[3456]86-sequent-sysv*
4622 i[3456]86-sequent-bsd*
4623 SPARC running LynxOS sparc-*-lynxos*
4624 SPARC running SunOS 4 sparc-*-sunos4*
4625 Tsqware Sparclet sparclet-*-*
4626 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4628 *** Changes in GDB 6.0:
4632 Support for debugging the Objective-C programming language has been
4633 integrated into GDB.
4635 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4637 DWARF 2's Call Frame Information makes available compiler generated
4638 information that more exactly describes the program's run-time stack.
4639 By using this information, GDB is able to provide more robust stack
4642 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4643 have been updated to use a new backtrace mechanism which includes
4644 DWARF 2 CFI support.
4648 GDB's remote protocol has been extended to include support for hosted
4649 file I/O (where the remote target uses GDB's file system). See GDB's
4650 remote protocol documentation for details.
4652 * All targets using the new architecture framework.
4654 All of GDB's targets have been updated to use the new internal
4655 architecture framework. The way is now open for future GDB releases
4656 to include cross-architecture native debugging support (i386 on amd64,
4659 * GNU/Linux's Thread Local Storage (TLS)
4661 GDB now includes support for for the GNU/Linux implementation of
4662 per-thread variables.
4664 * GNU/Linux's Native POSIX Thread Library (NPTL)
4666 GDB's thread code has been updated to work with either the new
4667 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4669 * Separate debug info.
4671 GDB, in conjunction with BINUTILS, now supports a mechanism for
4672 automatically loading debug information from a separate file. Instead
4673 of shipping full debug and non-debug versions of system libraries,
4674 system integrators can now instead ship just the stripped libraries
4675 and optional debug files.
4677 * DWARF 2 Location Expressions
4679 DWARF 2 Location Expressions allow the compiler to more completely
4680 describe the location of variables (even in optimized code) to the
4683 GDB now includes preliminary support for location expressions (support
4684 for DW_OP_piece is still missing).
4688 A number of long standing bugs that caused GDB to die while starting a
4689 Java application have been fixed. GDB's Java support is now
4690 considered "useable".
4692 * GNU/Linux support for fork, vfork, and exec.
4694 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4695 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4698 * GDB supports logging output to a file
4700 There are two new commands, "set logging" and "show logging", which can be
4701 used to capture GDB's output to a file.
4703 * The meaning of "detach" has changed for gdbserver
4705 The "detach" command will now resume the application, as documented. To
4706 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4709 * d10v, m68hc11 `regs' command deprecated
4711 The `info registers' command has been updated so that it displays the
4712 registers using a format identical to the old `regs' command.
4716 A new command, "maint set profile on/off", has been added. This command can
4717 be used to enable or disable profiling while running GDB, to profile a
4718 session or a set of commands. In addition there is a new configure switch,
4719 "--enable-profiling", which will cause GDB to be compiled with profiling
4720 data, for more informative profiling results.
4722 * Default MI syntax changed to "mi2".
4724 The default MI (machine interface) syntax, enabled by the command line
4725 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4726 "mi1", can be enabled by specifying the option "-i=mi1".
4728 Support for the original "mi0" syntax (included in GDB 5.0) has been
4731 Fix for gdb/192: removed extraneous space when displaying frame level.
4732 Fix for gdb/672: update changelist is now output in mi list format.
4733 Fix for gdb/702: a -var-assign that updates the value now shows up
4734 in a subsequent -var-update.
4736 * New native configurations.
4738 FreeBSD/amd64 x86_64-*-freebsd*
4740 * Multi-arched targets.
4742 HP/PA HPUX11 hppa*-*-hpux*
4743 Renesas M32R/D w/simulator m32r-*-elf*
4745 * OBSOLETE configurations and files
4747 Configurations that have been declared obsolete in this release have
4748 been commented out. Unless there is activity to revive these
4749 configurations, the next release of GDB will have their sources
4750 permanently REMOVED.
4752 Z8000 simulator z8k-zilog-none or z8ksim
4753 Matsushita MN10200 w/simulator mn10200-*-*
4754 H8/500 simulator h8500-hitachi-hms or h8500hms
4755 HP/PA running BSD hppa*-*-bsd*
4756 HP/PA running OSF/1 hppa*-*-osf*
4757 HP/PA Pro target hppa*-*-pro*
4758 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4759 Sequent family i[3456]86-sequent-sysv4*
4760 i[3456]86-sequent-sysv*
4761 i[3456]86-sequent-bsd*
4762 Tsqware Sparclet sparclet-*-*
4763 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4765 * REMOVED configurations and files
4768 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4769 IBM AIX PS/2 i[3456]86-*-aix
4770 i386 running Mach 3.0 i[3456]86-*-mach3*
4771 i386 running Mach i[3456]86-*-mach*
4772 i386 running OSF/1 i[3456]86-*osf1mk*
4773 HP/Apollo 68k Family m68*-apollo*-sysv*,
4775 m68*-hp-bsd*, m68*-hp-hpux*
4776 Argonaut Risc Chip (ARC) arc-*-*
4777 Mitsubishi D30V d30v-*-*
4778 Fujitsu FR30 fr30-*-elf*
4779 OS/9000 i[34]86-*-os9k
4780 I960 with MON960 i960-*-coff
4782 * MIPS $fp behavior changed
4784 The convenience variable $fp, for the MIPS, now consistently returns
4785 the address of the current frame's base. Previously, depending on the
4786 context, $fp could refer to either $sp or the current frame's base
4787 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4788 The GNU Source-Level Debugger''.
4790 *** Changes in GDB 5.3:
4792 * GNU/Linux shared library multi-threaded performance improved.
4794 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4795 `/proc', in preference to `ptrace' for memory reads. This may result
4796 in an improvement in the start-up time of multi-threaded, shared
4797 library applications when run under GDB. One GDB user writes: ``loads
4798 shared libs like mad''.
4800 * ``gdbserver'' now supports multi-threaded applications on some targets
4802 Support for debugging multi-threaded applications which use
4803 the GNU/Linux LinuxThreads package has been added for
4804 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4805 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4807 * GDB now supports C/C++ preprocessor macros.
4809 GDB now expands preprocessor macro invocations in C/C++ expressions,
4810 and provides various commands for showing macro definitions and how
4813 The new command `macro expand EXPRESSION' expands any macro
4814 invocations in expression, and shows the result.
4816 The new command `show macro MACRO-NAME' shows the definition of the
4817 macro named MACRO-NAME, and where it was defined.
4819 Most compilers don't include information about macros in the debugging
4820 information by default. In GCC 3.1, for example, you need to compile
4821 your program with the options `-gdwarf-2 -g3'. If the macro
4822 information is present in the executable, GDB will read it.
4824 * Multi-arched targets.
4826 DEC Alpha (partial) alpha*-*-*
4827 DEC VAX (partial) vax-*-*
4829 National Semiconductor NS32000 (partial) ns32k-*-*
4830 Motorola 68000 (partial) m68k-*-*
4831 Motorola MCORE mcore-*-*
4835 Fujitsu FRV architecture added by Red Hat frv*-*-*
4838 * New native configurations
4840 Alpha NetBSD alpha*-*-netbsd*
4841 SH NetBSD sh*-*-netbsdelf*
4842 MIPS NetBSD mips*-*-netbsd*
4843 UltraSPARC NetBSD sparc64-*-netbsd*
4845 * OBSOLETE configurations and files
4847 Configurations that have been declared obsolete in this release have
4848 been commented out. Unless there is activity to revive these
4849 configurations, the next release of GDB will have their sources
4850 permanently REMOVED.
4852 Mitsubishi D30V d30v-*-*
4853 OS/9000 i[34]86-*-os9k
4854 IBM AIX PS/2 i[3456]86-*-aix
4855 Fujitsu FR30 fr30-*-elf*
4856 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4857 Argonaut Risc Chip (ARC) arc-*-*
4858 i386 running Mach 3.0 i[3456]86-*-mach3*
4859 i386 running Mach i[3456]86-*-mach*
4860 i386 running OSF/1 i[3456]86-*osf1mk*
4861 HP/Apollo 68k Family m68*-apollo*-sysv*,
4863 m68*-hp-bsd*, m68*-hp-hpux*
4864 I960 with MON960 i960-*-coff
4866 * OBSOLETE languages
4868 CHILL, a Pascal like language used by telecommunications companies.
4870 * REMOVED configurations and files
4872 AMD 29k family via UDI a29k-amd-udi, udi29k
4873 A29K VxWorks a29k-*-vxworks
4874 AMD 29000 embedded, using EBMON a29k-none-none
4875 AMD 29000 embedded with COFF a29k-none-coff
4876 AMD 29000 embedded with a.out a29k-none-aout
4878 testsuite/gdb.hp/gdb.threads-hp/ directory
4880 * New command "set max-user-call-depth <nnn>"
4882 This command allows the user to limit the call depth of user-defined
4883 commands. The default is 1024.
4885 * Changes in FreeBSD/i386 native debugging.
4887 Support for the "generate-core-file" has been added.
4889 * New commands "dump", "append", and "restore".
4891 These commands allow data to be copied from target memory
4892 to a bfd-format or binary file (dump and append), and back
4893 from a file into memory (restore).
4895 * Improved "next/step" support on multi-processor Alpha Tru64.
4897 The previous single-step mechanism could cause unpredictable problems,
4898 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4899 of a software single-step mechanism prevents this.
4901 *** Changes in GDB 5.2.1:
4909 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4910 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4911 Fix, by Joel Brobecker imported from mainline.
4913 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4914 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4915 Fix, by Fred Fish, imported from mainline.
4917 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4918 Surprisingly enough, it works now.
4919 By Michal Ludvig, imported from mainline.
4921 i386 hardware watchpoint support:
4922 avoid misses on second run for some targets.
4923 By Pierre Muller, imported from mainline.
4925 *** Changes in GDB 5.2:
4927 * New command "set trust-readonly-sections on[off]".
4929 This command is a hint that tells gdb that read-only sections
4930 really are read-only (ie. that their contents will not change).
4931 In this mode, gdb will go to the object file rather than the
4932 target to read memory from read-only sections (such as ".text").
4933 This can be a significant performance improvement on some
4934 (notably embedded) targets.
4936 * New command "generate-core-file" (or "gcore").
4938 This new gdb command allows the user to drop a core file of the child
4939 process state at any time. So far it's been implemented only for
4940 GNU/Linux and Solaris, but should be relatively easily ported to other
4941 hosts. Argument is core file name (defaults to core.<pid>).
4943 * New command line option
4945 GDB now accepts --pid or -p followed by a process id.
4947 * Change in command line behavior -- corefiles vs. process ids.
4949 There is a subtle behavior in the way in which GDB handles
4950 command line arguments. The first non-flag argument is always
4951 a program to debug, but the second non-flag argument may either
4952 be a corefile or a process id. Previously, GDB would attempt to
4953 open the second argument as a corefile, and if that failed, would
4954 issue a superfluous error message and then attempt to attach it as
4955 a process. Now, if the second argument begins with a non-digit,
4956 it will be treated as a corefile. If it begins with a digit,
4957 GDB will attempt to attach it as a process, and if no such process
4958 is found, will then attempt to open it as a corefile.
4960 * Changes in ARM configurations.
4962 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4963 configuration is fully multi-arch.
4965 * New native configurations
4967 ARM NetBSD arm*-*-netbsd*
4968 x86 OpenBSD i[3456]86-*-openbsd*
4969 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4970 Sparc64 running FreeBSD sparc64-*-freebsd*
4974 Sanyo XStormy16 xstormy16-elf
4976 * OBSOLETE configurations and files
4978 Configurations that have been declared obsolete in this release have
4979 been commented out. Unless there is activity to revive these
4980 configurations, the next release of GDB will have their sources
4981 permanently REMOVED.
4983 AMD 29k family via UDI a29k-amd-udi, udi29k
4984 A29K VxWorks a29k-*-vxworks
4985 AMD 29000 embedded, using EBMON a29k-none-none
4986 AMD 29000 embedded with COFF a29k-none-coff
4987 AMD 29000 embedded with a.out a29k-none-aout
4989 testsuite/gdb.hp/gdb.threads-hp/ directory
4991 * REMOVED configurations and files
4993 TI TMS320C80 tic80-*-*
4995 PowerPC Solaris powerpcle-*-solaris*
4996 PowerPC Windows NT powerpcle-*-cygwin32
4997 PowerPC Netware powerpc-*-netware*
4998 Harris/CXUX m88k m88*-harris-cxux*
4999 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5000 ns32k-utek-sysv* ns32k-utek-*
5001 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5002 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5003 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5004 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5005 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5007 * Changes to command line processing
5009 The new `--args' feature can be used to specify command-line arguments
5010 for the inferior from gdb's command line.
5012 * Changes to key bindings
5014 There is a new `operate-and-get-next' function bound to `C-o'.
5016 *** Changes in GDB 5.1.1
5018 Fix compile problem on DJGPP.
5020 Fix a problem with floating-point registers on the i386 being
5023 Fix to stop GDB crashing on .debug_str debug info.
5025 Numerous documentation fixes.
5027 Numerous testsuite fixes.
5029 *** Changes in GDB 5.1:
5031 * New native configurations
5033 Alpha FreeBSD alpha*-*-freebsd*
5034 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5035 MIPS GNU/Linux mips*-*-linux*
5036 MIPS SGI Irix 6.x mips*-sgi-irix6*
5037 ia64 AIX ia64-*-aix*
5038 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5042 Motorola 68HC11 and 68HC12 m68hc11-elf
5044 UltraSparc running GNU/Linux sparc64-*-linux*
5046 * OBSOLETE configurations and files
5048 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5049 Harris/CXUX m88k m88*-harris-cxux*
5050 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5051 ns32k-utek-sysv* ns32k-utek-*
5052 TI TMS320C80 tic80-*-*
5054 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5055 PowerPC Solaris powerpcle-*-solaris*
5056 PowerPC Windows NT powerpcle-*-cygwin32
5057 PowerPC Netware powerpc-*-netware*
5058 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5059 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5060 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5061 Apple Macintosh (MPW) host N/A
5063 stuff.c (Program to stuff files into a specially prepared space in kdb)
5064 kdb-start.c (Main loop for the standalone kernel debugger)
5066 Configurations that have been declared obsolete in this release have
5067 been commented out. Unless there is activity to revive these
5068 configurations, the next release of GDB will have their sources
5069 permanently REMOVED.
5071 * REMOVED configurations and files
5073 Altos 3068 m68*-altos-*
5074 Convex c1-*-*, c2-*-*
5076 ARM RISCix arm-*-* (as host)
5080 * GDB has been converted to ISO C.
5082 GDB's source code has been converted to ISO C. In particular, the
5083 sources are fully protoized, and rely on standard headers being
5088 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5090 * The MI enabled by default.
5092 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5093 revised and enabled by default. Packages which use GDB as a debugging
5094 engine behind a UI or another front end are encouraged to switch to
5095 using the GDB/MI interface, instead of the old annotations interface
5096 which is now deprecated.
5098 * Support for debugging Pascal programs.
5100 GDB now includes support for debugging Pascal programs. The following
5101 main features are supported:
5103 - Pascal-specific data types such as sets;
5105 - automatic recognition of Pascal sources based on file-name
5108 - Pascal-style display of data types, variables, and functions;
5110 - a Pascal expression parser.
5112 However, some important features are not yet supported.
5114 - Pascal string operations are not supported at all;
5116 - there are some problems with boolean types;
5118 - Pascal type hexadecimal constants are not supported
5119 because they conflict with the internal variables format;
5121 - support for Pascal objects and classes is not full yet;
5123 - unlike Pascal, GDB is case-sensitive for symbol names.
5125 * Changes in completion.
5127 Commands such as `shell', `run' and `set args', which pass arguments
5128 to inferior programs, now complete on file names, similar to what
5129 users expect at the shell prompt.
5131 Commands which accept locations, such as `disassemble', `print',
5132 `breakpoint', `until', etc. now complete on filenames as well as
5133 program symbols. Thus, if you type "break foob TAB", and the source
5134 files linked into the programs include `foobar.c', that file name will
5135 be one of the candidates for completion. However, file names are not
5136 considered for completion after you typed a colon that delimits a file
5137 name from a name of a function in that file, as in "break foo.c:bar".
5139 `set demangle-style' completes on available demangling styles.
5141 * New platform-independent commands:
5143 It is now possible to define a post-hook for a command as well as a
5144 hook that runs before the command. For more details, see the
5145 documentation of `hookpost' in the GDB manual.
5147 * Changes in GNU/Linux native debugging.
5149 Support for debugging multi-threaded programs has been completely
5150 revised for all platforms except m68k and sparc. You can now debug as
5151 many threads as your system allows you to have.
5153 Attach/detach is supported for multi-threaded programs.
5155 Support for SSE registers was added for x86. This doesn't work for
5156 multi-threaded programs though.
5158 * Changes in MIPS configurations.
5160 Multi-arch support is enabled for all MIPS configurations.
5162 GDB can now be built as native debugger on SGI Irix 6.x systems for
5163 debugging n32 executables. (Debugging 64-bit executables is not yet
5166 * Unified support for hardware watchpoints in all x86 configurations.
5168 Most (if not all) native x86 configurations support hardware-assisted
5169 breakpoints and watchpoints in a unified manner. This support
5170 implements debug register sharing between watchpoints, which allows to
5171 put a virtually infinite number of watchpoints on the same address,
5172 and also supports watching regions up to 16 bytes with several debug
5175 The new maintenance command `maintenance show-debug-regs' toggles
5176 debugging print-outs in functions that insert, remove, and test
5177 watchpoints and hardware breakpoints.
5179 * Changes in the DJGPP native configuration.
5181 New command ``info dos sysinfo'' displays assorted information about
5182 the CPU, OS, memory, and DPMI server.
5184 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5185 display information about segment descriptors stored in GDT, LDT, and
5188 New commands ``info dos pde'' and ``info dos pte'' display entries
5189 from Page Directory and Page Tables (for now works with CWSDPMI only).
5190 New command ``info dos address-pte'' displays the Page Table entry for
5191 a given linear address.
5193 GDB can now pass command lines longer than 126 characters to the
5194 program being debugged (requires an update to the libdbg.a library
5195 which is part of the DJGPP development kit).
5197 DWARF2 debug info is now supported.
5199 It is now possible to `step' and `next' through calls to `longjmp'.
5201 * Changes in documentation.
5203 All GDB documentation was converted to GFDL, the GNU Free
5204 Documentation License.
5206 Tracepoints-related commands are now fully documented in the GDB
5209 TUI, the Text-mode User Interface, is now documented in the manual.
5211 Tracepoints-related commands are now fully documented in the GDB
5214 The "GDB Internals" manual now has an index. It also includes
5215 documentation of `ui_out' functions, GDB coding standards, x86
5216 hardware watchpoints, and memory region attributes.
5218 * GDB's version number moved to ``version.in''
5220 The Makefile variable VERSION has been replaced by the file
5221 ``version.in''. People creating GDB distributions should update the
5222 contents of this file.
5226 GUD support is now a standard part of the EMACS distribution.
5228 *** Changes in GDB 5.0:
5230 * Improved support for debugging FP programs on x86 targets
5232 Unified and much-improved support for debugging floating-point
5233 programs on all x86 targets. In particular, ``info float'' now
5234 displays the FP registers in the same format on all x86 targets, with
5235 greater level of detail.
5237 * Improvements and bugfixes in hardware-assisted watchpoints
5239 It is now possible to watch array elements, struct members, and
5240 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5241 on x86 targets no longer erroneously trigger when the address is
5244 * Improvements in the native DJGPP version of GDB
5246 The distribution now includes all the scripts and auxiliary files
5247 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5248 machines ``out of the box''.
5250 The DJGPP version can now debug programs that use signals. It is
5251 possible to catch signals that happened in the debuggee, deliver
5252 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5253 would kill the program being debugged.) Programs that hook hardware
5254 interrupts (keyboard, timer, etc.) can also be debugged.
5256 It is now possible to debug DJGPP programs that redirect their
5257 standard handles or switch them to raw (as opposed to cooked) mode, or
5258 even close them. The command ``run < foo > bar'' works as expected,
5259 and ``info terminal'' reports useful information about the debuggee's
5260 terminal, including raw/cooked mode, redirection, etc.
5262 The DJGPP version now uses termios functions for console I/O, which
5263 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5266 DOS-style file names with drive letters are now fully supported by
5269 It is now possible to debug DJGPP programs that switch their working
5270 directory. It is also possible to rerun the debuggee any number of
5271 times without restarting GDB; thus, you can use the same setup,
5272 breakpoints, etc. for many debugging sessions.
5274 * New native configurations
5276 ARM GNU/Linux arm*-*-linux*
5277 PowerPC GNU/Linux powerpc-*-linux*
5281 Motorola MCore mcore-*-*
5282 x86 VxWorks i[3456]86-*-vxworks*
5283 PowerPC VxWorks powerpc-*-vxworks*
5284 TI TMS320C80 tic80-*-*
5286 * OBSOLETE configurations
5288 Altos 3068 m68*-altos-*
5289 Convex c1-*-*, c2-*-*
5291 ARM RISCix arm-*-* (as host)
5294 Configurations that have been declared obsolete will be commented out,
5295 but the code will be left in place. If there is no activity to revive
5296 these configurations before the next release of GDB, the sources will
5297 be permanently REMOVED.
5299 * Gould support removed
5301 Support for the Gould PowerNode and NP1 has been removed.
5303 * New features for SVR4
5305 On SVR4 native platforms (such as Solaris), if you attach to a process
5306 without first loading a symbol file, GDB will now attempt to locate and
5307 load symbols from the running process's executable file.
5309 * Many C++ enhancements
5311 C++ support has been greatly improved. Overload resolution now works properly
5312 in almost all cases. RTTI support is on the way.
5314 * Remote targets can connect to a sub-program
5316 A popen(3) style serial-device has been added. This device starts a
5317 sub-process (such as a stand-alone simulator) and then communicates
5318 with that. The sub-program to run is specified using the syntax
5319 ``|<program> <args>'' vis:
5321 (gdb) set remotedebug 1
5322 (gdb) target extended-remote |mn10300-elf-sim program-args
5324 * MIPS 64 remote protocol
5326 A long standing bug in the mips64 remote protocol where by GDB
5327 expected certain 32 bit registers (ex SR) to be transfered as 32
5328 instead of 64 bits has been fixed.
5330 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5331 added to provide backward compatibility with older versions of GDB.
5333 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5335 The command ``set remotebinarydownload'' command has been replaced by
5336 ``set remote X-packet''. Other commands in ``set remote'' family
5337 include ``set remote P-packet''.
5339 * Breakpoint commands accept ranges.
5341 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5342 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5343 ``tracepoint passcount'' also accepts a range of tracepoints.
5345 * ``apropos'' command added.
5347 The ``apropos'' command searches through command names and
5348 documentation strings, printing out matches, making it much easier to
5349 try to find a command that does what you are looking for.
5353 A new machine oriented interface (MI) has been added to GDB. This
5354 interface is designed for debug environments running GDB as a separate
5355 process. This is part of the long term libGDB project. See the
5356 "GDB/MI" chapter of the GDB manual for further information. It can be
5357 enabled by configuring with:
5359 .../configure --enable-gdbmi
5361 *** Changes in GDB-4.18:
5363 * New native configurations
5365 HP-UX 10.20 hppa*-*-hpux10.20
5366 HP-UX 11.x hppa*-*-hpux11.0*
5367 M68K GNU/Linux m68*-*-linux*
5371 Fujitsu FR30 fr30-*-elf*
5372 Intel StrongARM strongarm-*-*
5373 Mitsubishi D30V d30v-*-*
5375 * OBSOLETE configurations
5377 Gould PowerNode, NP1 np1-*-*, pn-*-*
5379 Configurations that have been declared obsolete will be commented out,
5380 but the code will be left in place. If there is no activity to revive
5381 these configurations before the next release of GDB, the sources will
5382 be permanently REMOVED.
5386 As a compatibility experiment, GDB's source files buildsym.h and
5387 buildsym.c have been converted to pure standard C, no longer
5388 containing any K&R compatibility code. We believe that all systems in
5389 use today either come with a standard C compiler, or have a GCC port
5390 available. If this is not true, please report the affected
5391 configuration to bug-gdb@gnu.org immediately. See the README file for
5392 information about getting a standard C compiler if you don't have one
5397 GDB now uses readline 2.2.
5399 * set extension-language
5401 You can now control the mapping between filename extensions and source
5402 languages by using the `set extension-language' command. For instance,
5403 you can ask GDB to treat .c files as C++ by saying
5404 set extension-language .c c++
5405 The command `info extensions' lists all of the recognized extensions
5406 and their associated languages.
5408 * Setting processor type for PowerPC and RS/6000
5410 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5411 you can use the `set processor' command to specify what variant of the
5412 PowerPC family you are debugging. The command
5416 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5417 following PowerPC and RS6000 variants:
5419 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5420 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5422 403GC IBM PowerPC 403GC
5423 505 Motorola PowerPC 505
5424 860 Motorola PowerPC 860 or 850
5425 601 Motorola PowerPC 601
5426 602 Motorola PowerPC 602
5427 603 Motorola/IBM PowerPC 603 or 603e
5428 604 Motorola PowerPC 604 or 604e
5429 750 Motorola/IBM PowerPC 750 or 750
5431 At the moment, this command just tells GDB what to name the
5432 special-purpose processor registers. Since almost all the affected
5433 registers are inaccessible to user-level programs, this command is
5434 only useful for remote debugging in its present form.
5438 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5439 more extensive support for HP-UX. Added features include shared
5440 library support, kernel threads and hardware watchpoints for 11.00,
5441 support for HP's ANSI C and C++ compilers, and a compatibility mode
5442 for xdb and dbx commands.
5446 HP's donation includes the new concept of catchpoints, which is a
5447 generalization of the old catch command. On HP-UX, it is now possible
5448 to catch exec, fork, and vfork, as well as library loading.
5450 This means that the existing catch command has changed; its first
5451 argument now specifies the type of catch to be set up. See the
5452 output of "help catch" for a list of catchpoint types.
5454 * Debugging across forks
5456 On HP-UX, you can choose which process to debug when a fork() happens
5461 HP has donated a curses-based terminal user interface (TUI). To get
5462 it, build with --enable-tui. Although this can be enabled for any
5463 configuration, at present it only works for native HP debugging.
5465 * GDB remote protocol additions
5467 A new protocol packet 'X' that writes binary data is now available.
5468 Default behavior is to try 'X', then drop back to 'M' if the stub
5469 fails to respond. The settable variable `remotebinarydownload'
5470 allows explicit control over the use of 'X'.
5472 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5473 full 64-bit address. The command
5475 set remoteaddresssize 32
5477 can be used to revert to the old behaviour. For existing remote stubs
5478 the change should not be noticed, as the additional address information
5481 In order to assist in debugging stubs, you may use the maintenance
5482 command `packet' to send any text string to the stub. For instance,
5484 maint packet heythere
5486 sends the packet "$heythere#<checksum>". Note that it is very easy to
5487 disrupt a debugging session by sending the wrong packet at the wrong
5490 The compare-sections command allows you to compare section data on the
5491 target to what is in the executable file without uploading or
5492 downloading, by comparing CRC checksums.
5494 * Tracing can collect general expressions
5496 You may now collect general expressions at tracepoints. This requires
5497 further additions to the target-side stub; see tracepoint.c and
5498 doc/agentexpr.texi for further details.
5500 * mask-address variable for Mips
5502 For Mips targets, you may control the zeroing of the upper 32 bits of
5503 a 64-bit address by entering `set mask-address on'. This is mainly
5504 of interest to users of embedded R4xxx and R5xxx processors.
5506 * Higher serial baud rates
5508 GDB's serial code now allows you to specify baud rates 57600, 115200,
5509 230400, and 460800 baud. (Note that your host system may not be able
5510 to achieve all of these rates.)
5514 The i960 configuration now includes an initial implementation of a
5515 builtin simulator, contributed by Jim Wilson.
5518 *** Changes in GDB-4.17:
5520 * New native configurations
5522 Alpha GNU/Linux alpha*-*-linux*
5523 Unixware 2.x i[3456]86-unixware2*
5524 Irix 6.x mips*-sgi-irix6*
5525 PowerPC GNU/Linux powerpc-*-linux*
5526 PowerPC Solaris powerpcle-*-solaris*
5527 Sparc GNU/Linux sparc-*-linux*
5528 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5532 Argonaut Risc Chip (ARC) arc-*-*
5533 Hitachi H8/300S h8300*-*-*
5534 Matsushita MN10200 w/simulator mn10200-*-*
5535 Matsushita MN10300 w/simulator mn10300-*-*
5536 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5537 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5538 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5539 Mitsubishi D10V w/simulator d10v-*-*
5540 Mitsubishi M32R/D w/simulator m32r-*-elf*
5541 Tsqware Sparclet sparclet-*-*
5542 NEC V850 w/simulator v850-*-*
5544 * New debugging protocols
5546 ARM with RDI protocol arm*-*-*
5547 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5548 DDB and LSI variants of PMON protocol mips*-*-*
5549 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5550 PowerPC with SDS protocol powerpc{,le}-*-eabi
5551 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5555 All configurations can now understand and use the DWARF 2 debugging
5556 format. The choice is automatic, if the symbol file contains DWARF 2
5561 GDB now includes basic Java language support. This support is
5562 only useful with Java compilers that produce native machine code.
5564 * solib-absolute-prefix and solib-search-path
5566 For SunOS and SVR4 shared libraries, you may now set the prefix for
5567 loading absolute shared library symbol files, and the search path for
5568 locating non-absolute shared library symbol files.
5570 * Live range splitting
5572 GDB can now effectively debug code for which GCC has performed live
5573 range splitting as part of its optimization. See gdb/doc/LRS for
5574 more details on the expected format of the stabs information.
5578 GDB's support for the GNU Hurd, including thread debugging, has been
5579 updated to work with current versions of the Hurd.
5583 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5584 instruction set. ARM GDB automatically detects when Thumb
5585 instructions are in use, and adjusts disassembly and backtracing
5590 GDB's MIPS target configurations now handle the MIP16 16-bit
5595 GDB now includes support for overlays; if an executable has been
5596 linked such that multiple sections are based at the same address, GDB
5597 will decide which section to use for symbolic info. You can choose to
5598 control the decision manually, using overlay commands, or implement
5599 additional target-side support and use "overlay load-target" to bring
5600 in the overlay mapping. Do "help overlay" for more detail.
5604 The command "info symbol <address>" displays information about
5605 the symbol at the specified address.
5609 The standard remote protocol now includes an extension that allows
5610 asynchronous collection and display of trace data. This requires
5611 extensive support in the target-side debugging stub. Tracing mode
5612 includes a new interaction mode in GDB and new commands: see the
5613 file tracepoint.c for more details.
5617 Configurations for embedded MIPS now include a simulator contributed
5618 by Cygnus Solutions. The simulator supports the instruction sets
5619 of most MIPS variants.
5623 Sparc configurations may now include the ERC32 simulator contributed
5624 by the European Space Agency. The simulator is not built into
5625 Sparc targets by default; configure with --enable-sim to include it.
5629 For target configurations that may include multiple variants of a
5630 basic architecture (such as MIPS and SH), you may now set the
5631 architecture explicitly. "set arch" sets, "info arch" lists
5632 the possible architectures.
5634 *** Changes in GDB-4.16:
5636 * New native configurations
5638 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5639 M68K NetBSD m68k-*-netbsd*
5640 PowerPC AIX 4.x powerpc-*-aix*
5641 PowerPC MacOS powerpc-*-macos*
5642 PowerPC Windows NT powerpcle-*-cygwin32
5643 RS/6000 AIX 4.x rs6000-*-aix4*
5647 ARM with RDP protocol arm-*-*
5648 I960 with MON960 i960-*-coff
5649 MIPS VxWorks mips*-*-vxworks*
5650 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5651 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5653 Matra Sparclet sparclet-*-*
5657 The powerpc-eabi configuration now includes the PSIM simulator,
5658 contributed by Andrew Cagney, with assistance from Mike Meissner.
5659 PSIM is a very elaborate model of the PowerPC, including not only
5660 basic instruction set execution, but also details of execution unit
5661 performance and I/O hardware. See sim/ppc/README for more details.
5665 GDB now works with Solaris 2.5.
5667 * Windows 95/NT native
5669 GDB will now work as a native debugger on Windows 95 and Windows NT.
5670 To build it from source, you must use the "gnu-win32" environment,
5671 which uses a DLL to emulate enough of Unix to run the GNU tools.
5672 Further information, binaries, and sources are available at
5673 ftp.cygnus.com, under pub/gnu-win32.
5675 * dont-repeat command
5677 If a user-defined command includes the command `dont-repeat', then the
5678 command will not be repeated if the user just types return. This is
5679 useful if the command is time-consuming to run, so that accidental
5680 extra keystrokes don't run the same command many times.
5682 * Send break instead of ^C
5684 The standard remote protocol now includes an option to send a break
5685 rather than a ^C to the target in order to interrupt it. By default,
5686 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5688 * Remote protocol timeout
5690 The standard remote protocol includes a new variable `remotetimeout'
5691 that allows you to set the number of seconds before GDB gives up trying
5692 to read from the target. The default value is 2.
5694 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5696 By default GDB will automatically keep track of objects as they are
5697 loaded and unloaded by the dynamic linker. By using the command `set
5698 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5699 when shared library events occur, thus allowing you to set breakpoints
5700 in shared libraries which are explicitly loaded by the inferior.
5702 Note this feature does not work on hpux8. On hpux9 you must link
5703 /usr/lib/end.o into your program. This feature should work
5704 automatically on hpux10.
5706 * Irix 5.x hardware watchpoint support
5708 Irix 5 configurations now support the use of hardware watchpoints.
5710 * Mips protocol "SYN garbage limit"
5712 When debugging a Mips target using the `target mips' protocol, you
5713 may set the number of characters that GDB will ignore by setting
5714 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5715 every character. The default value is 1050.
5717 * Recording and replaying remote debug sessions
5719 If you set `remotelogfile' to the name of a file, gdb will write to it
5720 a recording of a remote debug session. This recording may then be
5721 replayed back to gdb using "gdbreplay". See gdbserver/README for
5722 details. This is useful when you have a problem with GDB while doing
5723 remote debugging; you can make a recording of the session and send it
5724 to someone else, who can then recreate the problem.
5726 * Speedups for remote debugging
5728 GDB includes speedups for downloading and stepping MIPS systems using
5729 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5730 and more efficient S-record downloading.
5732 * Memory use reductions and statistics collection
5734 GDB now uses less memory and reports statistics about memory usage.
5735 Try the `maint print statistics' command, for example.
5737 *** Changes in GDB-4.15:
5739 * Psymtabs for XCOFF
5741 The symbol reader for AIX GDB now uses partial symbol tables. This
5742 can greatly improve startup time, especially for large executables.
5744 * Remote targets use caching
5746 Remote targets now use a data cache to speed up communication with the
5747 remote side. The data cache could lead to incorrect results because
5748 it doesn't know about volatile variables, thus making it impossible to
5749 debug targets which use memory mapped I/O devices. `set remotecache
5750 off' turns the the data cache off.
5752 * Remote targets may have threads
5754 The standard remote protocol now includes support for multiple threads
5755 in the target system, using new protocol commands 'H' and 'T'. See
5756 gdb/remote.c for details.
5760 If GDB is configured with `--enable-netrom', then it will include
5761 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5762 acts as though it is a bank of ROM on the target board, but you can
5763 write into it over the network. GDB's support consists only of
5764 support for fast loading into the emulated ROM; to debug, you must use
5765 another protocol, such as standard remote protocol. The usual
5766 sequence is something like
5768 target nrom <netrom-hostname>
5770 target remote <netrom-hostname>:1235
5774 GDB now includes support for the Apple Macintosh, as a host only. It
5775 may be run as either an MPW tool or as a standalone application, and
5776 it can debug through the serial port. All the usual GDB commands are
5777 available, but to the target command, you must supply "serial" as the
5778 device type instead of "/dev/ttyXX". See mpw-README in the main
5779 directory for more information on how to build. The MPW configuration
5780 scripts */mpw-config.in support only a few targets, and only the
5781 mips-idt-ecoff target has been tested.
5785 GDB configuration now uses autoconf. This is not user-visible,
5786 but does simplify configuration and building.
5790 GDB now supports hpux10.
5792 *** Changes in GDB-4.14:
5794 * New native configurations
5796 x86 FreeBSD i[345]86-*-freebsd
5797 x86 NetBSD i[345]86-*-netbsd
5798 NS32k NetBSD ns32k-*-netbsd
5799 Sparc NetBSD sparc-*-netbsd
5803 A29K VxWorks a29k-*-vxworks
5804 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5805 CPU32 EST-300 emulator m68*-*-est*
5806 PowerPC ELF powerpc-*-elf
5809 * Alpha OSF/1 support for procfs
5811 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5812 possible to attach to running processes. As the mounting of the /proc
5813 filesystem is optional on the Alpha, GDB automatically determines
5814 the availability of /proc during startup. This can lead to problems
5815 if /proc is unmounted after GDB has been started.
5817 * Arguments to user-defined commands
5819 User commands may accept up to 10 arguments separated by whitespace.
5820 Arguments are accessed within the user command via $arg0..$arg9. A
5823 print $arg0 + $arg1 + $arg2
5825 To execute the command use:
5828 Defines the command "adder" which prints the sum of its three arguments.
5829 Note the arguments are text substitutions, so they may reference variables,
5830 use complex expressions, or even perform inferior function calls.
5832 * New `if' and `while' commands
5834 This makes it possible to write more sophisticated user-defined
5835 commands. Both commands take a single argument, which is the
5836 expression to evaluate, and must be followed by the commands to
5837 execute, one per line, if the expression is nonzero, the list being
5838 terminated by the word `end'. The `if' command list may include an
5839 `else' word, which causes the following commands to be executed only
5840 if the expression is zero.
5842 * Fortran source language mode
5844 GDB now includes partial support for Fortran 77. It will recognize
5845 Fortran programs and can evaluate a subset of Fortran expressions, but
5846 variables and functions may not be handled correctly. GDB will work
5847 with G77, but does not yet know much about symbols emitted by other
5850 * Better HPUX support
5852 Most debugging facilities now work on dynamic executables for HPPAs
5853 running hpux9 or later. You can attach to running dynamically linked
5854 processes, but by default the dynamic libraries will be read-only, so
5855 for instance you won't be able to put breakpoints in them. To change
5856 that behavior do the following before running the program:
5862 This will cause the libraries to be mapped private and read-write.
5863 To revert to the normal behavior, do this:
5869 You cannot set breakpoints or examine data in the library until after
5870 the library is loaded if the function/data symbols do not have
5873 GDB can now also read debug symbols produced by the HP C compiler on
5874 HPPAs (sorry, no C++, Fortran or 68k support).
5876 * Target byte order now dynamically selectable
5878 You can choose which byte order to use with a target system, via the
5879 commands "set endian big" and "set endian little", and you can see the
5880 current setting by using "show endian". You can also give the command
5881 "set endian auto", in which case GDB will use the byte order
5882 associated with the executable. Currently, only embedded MIPS
5883 configurations support dynamic selection of target byte order.
5885 * New DOS host serial code
5887 This version uses DPMI interrupts to handle buffered I/O, so you
5888 no longer need to run asynctsr when debugging boards connected to
5891 *** Changes in GDB-4.13:
5893 * New "complete" command
5895 This lists all the possible completions for the rest of the line, if it
5896 were to be given as a command itself. This is intended for use by emacs.
5898 * Trailing space optional in prompt
5900 "set prompt" no longer adds a space for you after the prompt you set. This
5901 allows you to set a prompt which ends in a space or one that does not.
5903 * Breakpoint hit counts
5905 "info break" now displays a count of the number of times the breakpoint
5906 has been hit. This is especially useful in conjunction with "ignore"; you
5907 can ignore a large number of breakpoint hits, look at the breakpoint info
5908 to see how many times the breakpoint was hit, then run again, ignoring one
5909 less than that number, and this will get you quickly to the last hit of
5912 * Ability to stop printing at NULL character
5914 "set print null-stop" will cause GDB to stop printing the characters of
5915 an array when the first NULL is encountered. This is useful when large
5916 arrays actually contain only short strings.
5918 * Shared library breakpoints
5920 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5921 breakpoints in shared libraries before the executable is run.
5923 * Hardware watchpoints
5925 There is a new hardware breakpoint for the watch command for sparclite
5926 targets. See gdb/sparclite/hw_breakpoint.note.
5928 Hardware watchpoints are also now supported under GNU/Linux.
5932 Annotations have been added. These are for use with graphical interfaces,
5933 and are still experimental. Currently only gdba.el uses these.
5935 * Improved Irix 5 support
5937 GDB now works properly with Irix 5.2.
5939 * Improved HPPA support
5941 GDB now works properly with the latest GCC and GAS.
5943 * New native configurations
5945 Sequent PTX4 i[34]86-sequent-ptx4
5946 HPPA running OSF/1 hppa*-*-osf*
5947 Atari TT running SVR4 m68*-*-sysv4*
5948 RS/6000 LynxOS rs6000-*-lynxos*
5952 OS/9000 i[34]86-*-os9k
5953 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5956 * Hitachi SH7000 and E7000-PC ICE support
5958 There is now support for communicating with the Hitachi E7000-PC ICE.
5959 This is available automatically when GDB is configured for the SH.
5963 As usual, a variety of small fixes and improvements, both generic
5964 and configuration-specific. See the ChangeLog for more detail.
5966 *** Changes in GDB-4.12:
5968 * Irix 5 is now supported
5972 GDB-4.12 on the HPPA has a number of changes which make it unable
5973 to debug the output from the currently released versions of GCC and
5974 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5975 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5976 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5979 *** Changes in GDB-4.11:
5981 * User visible changes:
5985 The "set remotedebug" option is now consistent between the mips remote
5986 target, remote targets using the gdb-specific protocol, UDI (AMD's
5987 debug protocol for the 29k) and the 88k bug monitor. It is now an
5988 integer specifying a debug level (normally 0 or 1, but 2 means more
5989 debugging info for the mips target).
5991 * DEC Alpha native support
5993 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5994 debug info, but GDB works fairly well with the DEC compiler and should
5995 work with a future GCC release. See the README file for a few
5996 Alpha-specific notes.
5998 * Preliminary thread implementation
6000 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6002 * LynxOS native and target support for 386
6004 This release has been hosted on LynxOS 2.2, and also can be configured
6005 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6008 * Improvements in C++ mangling/demangling.
6010 This release has much better g++ debugging, specifically in name
6011 mangling/demangling, virtual function calls, print virtual table,
6012 call methods, ...etc.
6014 *** Changes in GDB-4.10:
6016 * User visible changes:
6018 Remote debugging using the GDB-specific (`target remote') protocol now
6019 supports the `load' command. This is only useful if you have some
6020 other way of getting the stub to the target system, and you can put it
6021 somewhere in memory where it won't get clobbered by the download.
6023 Filename completion now works.
6025 When run under emacs mode, the "info line" command now causes the
6026 arrow to point to the line specified. Also, "info line" prints
6027 addresses in symbolic form (as well as hex).
6029 All vxworks based targets now support a user settable option, called
6030 vxworks-timeout. This option represents the number of seconds gdb
6031 should wait for responses to rpc's. You might want to use this if
6032 your vxworks target is, perhaps, a slow software simulator or happens
6033 to be on the far side of a thin network line.
6037 This release contains support for using a DEC alpha as a GDB host for
6038 cross debugging. Native alpha debugging is not supported yet.
6041 *** Changes in GDB-4.9:
6045 This is the first GDB release which is accompanied by a matching testsuite.
6046 The testsuite requires installation of dejagnu, which should be available
6047 via ftp from most sites that carry GNU software.
6051 'Cfront' style demangling has had its name changed to 'ARM' style, to
6052 emphasize that it was written from the specifications in the C++ Annotated
6053 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6054 disclaimers, it still generated too much confusion with users attempting to
6055 use gdb with AT&T cfront.
6059 GDB now uses a standard remote interface to a simulator library.
6060 So far, the library contains simulators for the Zilog Z8001/2, the
6061 Hitachi H8/300, H8/500 and Super-H.
6063 * New targets supported
6065 H8/300 simulator h8300-hitachi-hms or h8300hms
6066 H8/500 simulator h8500-hitachi-hms or h8500hms
6067 SH simulator sh-hitachi-hms or sh
6068 Z8000 simulator z8k-zilog-none or z8ksim
6069 IDT MIPS board over serial line mips-idt-ecoff
6071 Cross-debugging to GO32 targets is supported. It requires a custom
6072 version of the i386-stub.c module which is integrated with the
6073 GO32 memory extender.
6075 * New remote protocols
6077 MIPS remote debugging protocol.
6079 * New source languages supported
6081 This version includes preliminary support for Chill, a Pascal like language
6082 used by telecommunications companies. Chill support is also being integrated
6083 into the GNU compiler, but we don't know when it will be publically available.
6086 *** Changes in GDB-4.8:
6088 * HP Precision Architecture supported
6090 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6091 version of this support was available as a set of patches from the
6092 University of Utah. GDB does not support debugging of programs
6093 compiled with the HP compiler, because HP will not document their file
6094 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6095 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6097 Many problems in the preliminary version have been fixed.
6099 * Faster and better demangling
6101 We have improved template demangling and fixed numerous bugs in the GNU style
6102 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6103 character types (wchar_t) are now supported. Demangling of each symbol is now
6104 only done once, and is cached when the symbol table for a file is read in.
6105 This results in a small increase in memory usage for C programs, a moderate
6106 increase in memory usage for C++ programs, and a fantastic speedup in
6109 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6110 from the specifications in the Annotated Reference Manual, which AT&T's
6111 compiler does not actually implement.
6113 * G++ multiple inheritance compiler problem
6115 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6116 inheritance lattices was reworked to properly discover ambiguities. We
6117 recently found an example which causes this new algorithm to fail in a
6118 very subtle way, producing bad debug information for those classes.
6119 The file 'gcc.patch' (in this directory) can be applied to gcc to
6120 circumvent the problem. A future GCC release will contain a complete
6123 The previous G++ debug info problem (mentioned below for the gdb-4.7
6124 release) is fixed in gcc version 2.3.2.
6126 * Improved configure script
6128 The `configure' script will now attempt to guess your system type if
6129 you don't supply a host system type. The old scheme of supplying a
6130 host system triplet is preferable over using this. All the magic is
6131 done in the new `config.guess' script. Examine it for details.
6133 We have also brought our configure script much more in line with the FSF's
6134 version. It now supports the --with-xxx options. In particular,
6135 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6136 The resulting GDB will not be able to read arbitrary object file formats --
6137 only the format ``expected'' to be used on the configured target system.
6138 We hope to make this the default in a future release.
6140 * Documentation improvements
6142 There's new internal documentation on how to modify GDB, and how to
6143 produce clean changes to the code. We implore people to read it
6144 before submitting changes.
6146 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6147 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6148 `info' files are also provided. To build `info' files from scratch,
6149 you will need the latest `makeinfo' release, which will be available in
6150 a future texinfo-X.Y release.
6152 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6153 We're not sure exactly which versions have this problem, but it has
6154 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6155 or better. If that isn't possible, there is a patch in
6156 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6157 around this problem.
6161 GDB now supports array constants that can be used in expressions typed in by
6162 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6163 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6166 The new directory `gdb/sparclite' contains a program that demonstrates
6167 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6169 * New native hosts supported
6171 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6172 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6174 * New targets supported
6176 AMD 29k family via UDI a29k-amd-udi or udi29k
6178 * New file formats supported
6180 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6181 HPUX core files, and SCO 3.2v2 core files.
6185 Attaching to processes now works again; thanks for the many bug reports.
6187 We have also stomped on a bunch of core dumps caused by
6188 printf_filtered("%s") problems.
6190 We eliminated a copyright problem on the rpc and ptrace header files
6191 for VxWorks, which was discovered at the last minute during the 4.7
6192 release. You should now be able to build a VxWorks GDB.
6194 You can now interrupt gdb while an attached process is running. This
6195 will cause the attached process to stop, and give control back to GDB.
6197 We fixed problems caused by using too many file descriptors
6198 for reading symbols from object files and libraries. This was
6199 especially a problem for programs that used many (~100) shared
6202 The `step' command now only enters a subroutine if there is line number
6203 information for the subroutine. Otherwise it acts like the `next'
6204 command. Previously, `step' would enter subroutines if there was
6205 any debugging information about the routine. This avoids problems
6206 when using `cc -g1' on MIPS machines.
6208 * Internal improvements
6210 GDB's internal interfaces have been improved to make it easier to support
6211 debugging of multiple languages in the future.
6213 GDB now uses a common structure for symbol information internally.
6214 Minimal symbols (derived from linkage symbols in object files), partial
6215 symbols (from a quick scan of debug information), and full symbols
6216 contain a common subset of information, making it easier to write
6217 shared code that handles any of them.
6219 * New command line options
6221 We now accept --silent as an alias for --quiet.
6225 The memory-mapped-malloc library is now licensed under the GNU Library
6226 General Public License.
6228 *** Changes in GDB-4.7:
6230 * Host/native/target split
6232 GDB has had some major internal surgery to untangle the support for
6233 hosts and remote targets. Now, when you configure GDB for a remote
6234 target, it will no longer load in all of the support for debugging
6235 local programs on the host. When fully completed and tested, this will
6236 ensure that arbitrary host/target combinations are possible.
6238 The primary conceptual shift is to separate the non-portable code in
6239 GDB into three categories. Host specific code is required any time GDB
6240 is compiled on that host, regardless of the target. Target specific
6241 code relates to the peculiarities of the target, but can be compiled on
6242 any host. Native specific code is everything else: it can only be
6243 built when the host and target are the same system. Child process
6244 handling and core file support are two common `native' examples.
6246 GDB's use of /proc for controlling Unix child processes is now cleaner.
6247 It has been split out into a single module under the `target_ops' vector,
6248 plus two native-dependent functions for each system that uses /proc.
6250 * New hosts supported
6252 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6253 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6254 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6256 * New targets supported
6258 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6259 68030 and CPU32 m68030-*-*, m68332-*-*
6261 * New native hosts supported
6263 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6264 (386bsd is not well tested yet)
6265 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6267 * New file formats supported
6269 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6270 supports reading of `a.out.adobe' object files, which are an a.out
6271 format extended with minimal information about multiple sections.
6275 `show copying' is the same as the old `info copying'.
6276 `show warranty' is the same as `info warrantee'.
6277 These were renamed for consistency. The old commands continue to work.
6279 `info handle' is a new alias for `info signals'.
6281 You can now define pre-command hooks, which attach arbitrary command
6282 scripts to any command. The commands in the hook will be executed
6283 prior to the user's command. You can also create a hook which will be
6284 executed whenever the program stops. See gdb.texinfo.
6288 We now deal with Cfront style name mangling, and can even extract type
6289 info from mangled symbols. GDB can automatically figure out which
6290 symbol mangling style your C++ compiler uses.
6292 Calling of methods and virtual functions has been improved as well.
6296 The crash that occured when debugging Sun Ansi-C compiled binaries is
6297 fixed. This was due to mishandling of the extra N_SO stabs output
6300 We also finally got Ultrix 4.2 running in house, and fixed core file
6301 support, with help from a dozen people on the net.
6303 John M. Farrell discovered that the reason that single-stepping was so
6304 slow on all of the Mips based platforms (primarily SGI and DEC) was
6305 that we were trying to demangle and lookup a symbol used for internal
6306 purposes on every instruction that was being stepped through. Changing
6307 the name of that symbol so that it couldn't be mistaken for a C++
6308 mangled symbol sped things up a great deal.
6310 Rich Pixley sped up symbol lookups in general by getting much smarter
6311 about when C++ symbol mangling is necessary. This should make symbol
6312 completion (TAB on the command line) much faster. It's not as fast as
6313 we'd like, but it's significantly faster than gdb-4.6.
6317 A new user controllable variable 'call_scratch_address' can
6318 specify the location of a scratch area to be used when GDB
6319 calls a function in the target. This is necessary because the
6320 usual method of putting the scratch area on the stack does not work
6321 in systems that have separate instruction and data spaces.
6323 We integrated changes to support the 29k UDI (Universal Debugger
6324 Interface), but discovered at the last minute that we didn't have all
6325 of the appropriate copyright paperwork. We are working with AMD to
6326 resolve this, and hope to have it available soon.
6330 We have sped up the remote serial line protocol, especially for targets
6331 with lots of registers. It now supports a new `expedited status' ('T')
6332 message which can be used in place of the existing 'S' status message.
6333 This allows the remote stub to send only the registers that GDB
6334 needs to make a quick decision about single-stepping or conditional
6335 breakpoints, eliminating the need to fetch the entire register set for
6336 each instruction being stepped through.
6338 The GDB remote serial protocol now implements a write-through cache for
6339 registers, only re-reading the registers if the target has run.
6341 There is also a new remote serial stub for SPARC processors. You can
6342 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6343 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6344 processor with a serial port.
6348 Configure.in files have become much easier to read and modify. A new
6349 `table driven' format makes it more obvious what configurations are
6350 supported, and what files each one uses.
6354 There is a new opcodes library which will eventually contain all of the
6355 disassembly routines and opcode tables. At present, it only contains
6356 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6357 disassembler (binutils/objdump) to share these routines.
6359 The libiberty library is now copylefted under the GNU Library General
6360 Public License. This allows more liberal use, and was done so libg++
6361 can use it. This makes no difference to GDB, since the Library License
6362 grants all the rights from the General Public License.
6366 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6367 reference to the stabs symbol info used by the debugger. It is (as far
6368 as we know) the only published document on this fascinating topic. We
6369 encourage you to read it, compare it to the stabs information on your
6370 system, and send improvements on the document in general (to
6371 bug-gdb@prep.ai.mit.edu).
6373 And, of course, many bugs have been fixed.
6376 *** Changes in GDB-4.6:
6378 * Better support for C++ function names
6380 GDB now accepts as input the "demangled form" of C++ overloaded function
6381 names and member function names, and can do command completion on such names
6382 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6383 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6384 Make use of command completion, it is your friend.
6386 GDB also now accepts a variety of C++ mangled symbol formats. They are
6387 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6388 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6389 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6390 for the list of formats.
6392 * G++ symbol mangling problem
6394 Recent versions of gcc have a bug in how they emit debugging information for
6395 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6396 directory) can be applied to gcc to fix the problem. Alternatively, if you
6397 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6398 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6399 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6402 * New 'maintenance' command
6404 All of the commands related to hacking GDB internals have been moved out of
6405 the main command set, and now live behind the 'maintenance' command. This
6406 can also be abbreviated as 'mt'. The following changes were made:
6408 dump-me -> maintenance dump-me
6409 info all-breakpoints -> maintenance info breakpoints
6410 printmsyms -> maintenance print msyms
6411 printobjfiles -> maintenance print objfiles
6412 printpsyms -> maintenance print psymbols
6413 printsyms -> maintenance print symbols
6415 The following commands are new:
6417 maintenance demangle Call internal GDB demangler routine to
6418 demangle a C++ link name and prints the result.
6419 maintenance print type Print a type chain for a given symbol
6421 * Change to .gdbinit file processing
6423 We now read the $HOME/.gdbinit file before processing the argv arguments
6424 (e.g. reading symbol files or core files). This allows global parameters to
6425 be set, which will apply during the symbol reading. The ./.gdbinit is still
6426 read after argv processing.
6428 * New hosts supported
6430 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6432 GNU/Linux support i386-unknown-linux or linux
6434 We are also including code to support the HP/PA running BSD and HPUX. This
6435 is almost guaranteed not to work, as we didn't have time to test or build it
6436 for this release. We are including it so that the more adventurous (or
6437 masochistic) of you can play with it. We also had major problems with the
6438 fact that the compiler that we got from HP doesn't support the -g option.
6441 * New targets supported
6443 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6445 * More smarts about finding #include files
6447 GDB now remembers the compilation directory for all include files, and for
6448 all files from which C is generated (like yacc and lex sources). This
6449 greatly improves GDB's ability to find yacc/lex sources, and include files,
6450 especially if you are debugging your program from a directory different from
6451 the one that contains your sources.
6453 We also fixed a bug which caused difficulty with listing and setting
6454 breakpoints in include files which contain C code. (In the past, you had to
6455 try twice in order to list an include file that you hadn't looked at before.)
6457 * Interesting infernals change
6459 GDB now deals with arbitrary numbers of sections, where the symbols for each
6460 section must be relocated relative to that section's landing place in the
6461 target's address space. This work was needed to support ELF with embedded
6462 stabs used by Solaris-2.0.
6464 * Bug fixes (of course!)
6466 There have been loads of fixes for the following things:
6467 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6468 i960, stabs, DOS(GO32), procfs, etc...
6470 See the ChangeLog for details.
6472 *** Changes in GDB-4.5:
6474 * New machines supported (host and target)
6476 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6478 SGI Irix-4.x mips-sgi-irix4 or iris4
6480 * New malloc package
6482 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6483 Mmalloc is capable of handling mutiple heaps of memory. It is also
6484 capable of saving a heap to a file, and then mapping it back in later.
6485 This can be used to greatly speedup the startup of GDB by using a
6486 pre-parsed symbol table which lives in a mmalloc managed heap. For
6487 more details, please read mmalloc/mmalloc.texi.
6491 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6492 'help info proc' for details.
6494 * MIPS ecoff symbol table format
6496 The code that reads MIPS symbol table format is now supported on all hosts.
6497 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6500 * File name changes for MS-DOS
6502 Many files in the config directories have been renamed to make it easier to
6503 support GDB on MS-DOSe systems (which have very restrictive file name
6504 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6505 environment) is close to working but has some remaining problems. Note
6506 that debugging of DOS programs is not supported, due to limitations
6507 in the ``operating system'', but it can be used to host cross-debugging.
6509 * Cross byte order fixes
6511 Many fixes have been made to support cross debugging of Sparc and MIPS
6512 targets from hosts whose byte order differs.
6514 * New -mapped and -readnow options
6516 If memory-mapped files are available on your system through the 'mmap'
6517 system call, you can use the -mapped option on the `file' or
6518 `symbol-file' commands to cause GDB to write the symbols from your
6519 program into a reusable file. If the program you are debugging is
6520 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6521 Future GDB debugging sessions will notice the presence of this file,
6522 and will quickly map in symbol information from it, rather than reading
6523 the symbol table from the executable program. Using the '-mapped'
6524 option in a GDB `file' or `symbol-file' command has the same effect as
6525 starting GDB with the '-mapped' command-line option.
6527 You can cause GDB to read the entire symbol table immediately by using
6528 the '-readnow' option with any of the commands that load symbol table
6529 information (or on the GDB command line). This makes the command
6530 slower, but makes future operations faster.
6532 The -mapped and -readnow options are typically combined in order to
6533 build a `fred.syms' file that contains complete symbol information.
6534 A simple GDB invocation to do nothing but build a `.syms' file for future
6537 gdb -batch -nx -mapped -readnow programname
6539 The `.syms' file is specific to the host machine on which GDB is run.
6540 It holds an exact image of GDB's internal symbol table. It cannot be
6541 shared across multiple host platforms.
6543 * longjmp() handling
6545 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6546 siglongjmp() without losing control. This feature has not yet been ported to
6547 all systems. It currently works on many 386 platforms, all MIPS-based
6548 platforms (SGI, DECstation, etc), and Sun3/4.
6552 Preliminary work has been put in to support the new Solaris OS from Sun. At
6553 this time, it can control and debug processes, but it is not capable of
6558 As always, many many bug fixes. The major areas were with g++, and mipsread.
6559 People using the MIPS-based platforms should experience fewer mysterious
6560 crashes and trashed symbol tables.
6562 *** Changes in GDB-4.4:
6564 * New machines supported (host and target)
6566 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6568 BSD Reno on Vax vax-dec-bsd
6569 Ultrix on Vax vax-dec-ultrix
6571 * New machines supported (target)
6573 AMD 29000 embedded, using EBMON a29k-none-none
6577 GDB continues to improve its handling of C++. `References' work better.
6578 The demangler has also been improved, and now deals with symbols mangled as
6579 per the Annotated C++ Reference Guide.
6581 GDB also now handles `stabs' symbol information embedded in MIPS
6582 `ecoff' symbol tables. Since the ecoff format was not easily
6583 extensible to handle new languages such as C++, this appeared to be a
6584 good way to put C++ debugging info into MIPS binaries. This option
6585 will be supported in the GNU C compiler, version 2, when it is
6588 * New features for SVR4
6590 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6591 shared libraries. Debugging dynamically linked programs should present
6592 only minor differences from debugging statically linked programs.
6594 The `info proc' command will print out information about any process
6595 on an SVR4 system (including the one you are debugging). At the moment,
6596 it prints the address mappings of the process.
6598 If you bring up GDB on another SVR4 system, please send mail to
6599 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6601 * Better dynamic linking support in SunOS
6603 Reading symbols from shared libraries which contain debugging symbols
6604 now works properly. However, there remain issues such as automatic
6605 skipping of `transfer vector' code during function calls, which
6606 make it harder to debug code in a shared library, than to debug the
6607 same code linked statically.
6611 GDB is now using the latest `getopt' routines from the FSF. This
6612 version accepts the -- prefix for options with long names. GDB will
6613 continue to accept the old forms (-option and +option) as well.
6614 Various single letter abbreviations for options have been explicity
6615 added to the option table so that they won't get overshadowed in the
6616 future by other options that begin with the same letter.
6620 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6621 Many assorted bugs have been handled. Many more remain to be handled.
6622 See the various ChangeLog files (primarily in gdb and bfd) for details.
6625 *** Changes in GDB-4.3:
6627 * New machines supported (host and target)
6629 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6630 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6631 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6633 * Almost SCO Unix support
6635 We had hoped to support:
6636 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6637 (except for core file support), but we discovered very late in the release
6638 that it has problems with process groups that render gdb unusable. Sorry
6639 about that. I encourage people to fix it and post the fixes.
6641 * Preliminary ELF and DWARF support
6643 GDB can read ELF object files on System V Release 4, and can handle
6644 debugging records for C, in DWARF format, in ELF files. This support
6645 is preliminary. If you bring up GDB on another SVR4 system, please
6646 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6651 GDB now uses the latest `readline' library. One user-visible change
6652 is that two tabs will list possible command completions, which previously
6653 required typing M-? (meta-question mark, or ESC ?).
6657 The `stepi' bug that many of you noticed has been squashed.
6658 Many bugs in C++ have been handled. Many more remain to be handled.
6659 See the various ChangeLog files (primarily in gdb and bfd) for details.
6661 * State of the MIPS world (in case you wondered):
6663 GDB can understand the symbol tables emitted by the compilers
6664 supplied by most vendors of MIPS-based machines, including DEC. These
6665 symbol tables are in a format that essentially nobody else uses.
6667 Some versions of gcc come with an assembler post-processor called
6668 mips-tfile. This program is required if you want to do source-level
6669 debugging of gcc-compiled programs. I believe FSF does not ship
6670 mips-tfile with gcc version 1, but it will eventually come with gcc
6673 Debugging of g++ output remains a problem. g++ version 1.xx does not
6674 really support it at all. (If you're lucky, you should be able to get
6675 line numbers and stack traces to work, but no parameters or local
6676 variables.) With some work it should be possible to improve the
6679 When gcc version 2 is released, you will have somewhat better luck.
6680 However, even then you will get confusing results for inheritance and
6683 We will eventually provide full debugging of g++ output on
6684 DECstations. This will probably involve some kind of stabs-in-ecoff
6685 encapulation, but the details have not been worked out yet.
6688 *** Changes in GDB-4.2:
6690 * Improved configuration
6692 Only one copy of `configure' exists now, and it is not self-modifying.
6693 Porting BFD is simpler.
6697 The `step' and `next' commands now only stop at the first instruction
6698 of a source line. This prevents the multiple stops that used to occur
6699 in switch statements, for-loops, etc. `Step' continues to stop if a
6700 function that has debugging information is called within the line.
6704 Lots of small bugs fixed. More remain.
6706 * New host supported (not target)
6708 Intel 386 PC clone running Mach i386-none-mach
6711 *** Changes in GDB-4.1:
6713 * Multiple source language support
6715 GDB now has internal scaffolding to handle several source languages.
6716 It determines the type of each source file from its filename extension,
6717 and will switch expression parsing and number formatting to match the
6718 language of the function in the currently selected stack frame.
6719 You can also specifically set the language to be used, with
6720 `set language c' or `set language modula-2'.
6724 GDB now has preliminary support for the GNU Modula-2 compiler,
6725 currently under development at the State University of New York at
6726 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6727 continue through the fall of 1991 and into 1992.
6729 Other Modula-2 compilers are currently not supported, and attempting to
6730 debug programs compiled with them will likely result in an error as the
6731 symbol table is read. Feel free to work on it, though!
6733 There are hooks in GDB for strict type checking and range checking,
6734 in the `Modula-2 philosophy', but they do not currently work.
6738 GDB can now write to executable and core files (e.g. patch
6739 a variable's value). You must turn this switch on, specify
6740 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6741 by assigning a new value to a variable. Modifications take
6744 * Automatic SunOS shared library reading
6746 When you run your program, GDB automatically determines where its
6747 shared libraries (if any) have been loaded, and reads their symbols.
6748 The `share' command is no longer needed. This also works when
6749 examining core files.
6753 You can specify the number of lines that the `list' command shows.
6756 * New machines supported (host and target)
6758 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6759 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6760 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6762 * New hosts supported (not targets)
6764 IBM RT/PC: romp-ibm-aix or rtpc
6766 * New targets supported (not hosts)
6768 AMD 29000 embedded with COFF a29k-none-coff
6769 AMD 29000 embedded with a.out a29k-none-aout
6770 Ultracomputer remote kernel debug a29k-nyu-kern
6772 * New remote interfaces
6778 *** Changes in GDB-4.0:
6782 Wide output is wrapped at good places to make the output more readable.
6784 Gdb now supports cross-debugging from a host machine of one type to a
6785 target machine of another type. Communication with the target system
6786 is over serial lines. The ``target'' command handles connecting to the
6787 remote system; the ``load'' command will download a program into the
6788 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6789 also supports debugging of realtime processes running under VxWorks,
6790 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6791 stub on the target system.
6793 New CPUs supported include the AMD 29000 and Intel 960.
6795 GDB now reads object files and symbol tables via a ``binary file''
6796 library, which allows a single copy of GDB to debug programs of multiple
6797 object file types such as a.out and coff.
6799 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6800 refcard.dvi and refcard.ps are available to format it).
6803 * Control-Variable user interface simplified
6805 All variables that control the operation of the debugger can be set
6806 by the ``set'' command, and displayed by the ``show'' command.
6808 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6809 ``Show prompt'' produces the response:
6810 Gdb's prompt is new-gdb=>.
6812 What follows are the NEW set commands. The command ``help set'' will
6813 print a complete list of old and new set commands. ``help set FOO''
6814 will give a longer description of the variable FOO. ``show'' will show
6815 all of the variable descriptions and their current settings.
6817 confirm on/off: Enables warning questions for operations that are
6818 hard to recover from, e.g. rerunning the program while
6819 it is already running. Default is ON.
6821 editing on/off: Enables EMACS style command line editing
6822 of input. Previous lines can be recalled with
6823 control-P, the current line can be edited with control-B,
6824 you can search for commands with control-R, etc.
6827 history filename NAME: NAME is where the gdb command history
6828 will be stored. The default is .gdb_history,
6829 or the value of the environment variable
6832 history size N: The size, in commands, of the command history. The
6833 default is 256, or the value of the environment variable
6836 history save on/off: If this value is set to ON, the history file will
6837 be saved after exiting gdb. If set to OFF, the
6838 file will not be saved. The default is OFF.
6840 history expansion on/off: If this value is set to ON, then csh-like
6841 history expansion will be performed on
6842 command line input. The default is OFF.
6844 radix N: Sets the default radix for input and output. It can be set
6845 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6846 in the current radix, so "set radix 10" is always a no-op.
6848 height N: This integer value is the number of lines on a page. Default
6849 is 24, the current `stty rows'' setting, or the ``li#''
6850 setting from the termcap entry matching the environment
6853 width N: This integer value is the number of characters on a line.
6854 Default is 80, the current `stty cols'' setting, or the ``co#''
6855 setting from the termcap entry matching the environment
6858 Note: ``set screensize'' is obsolete. Use ``set height'' and
6859 ``set width'' instead.
6861 print address on/off: Print memory addresses in various command displays,
6862 such as stack traces and structure values. Gdb looks
6863 more ``symbolic'' if you turn this off; it looks more
6864 ``machine level'' with it on. Default is ON.
6866 print array on/off: Prettyprint arrays. New convenient format! Default
6869 print demangle on/off: Print C++ symbols in "source" form if on,
6872 print asm-demangle on/off: Same, for assembler level printouts
6875 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6878 * Support for Epoch Environment.
6880 The epoch environment is a version of Emacs v18 with windowing. One
6881 new command, ``inspect'', is identical to ``print'', except that if you
6882 are running in the epoch environment, the value is printed in its own
6886 * Support for Shared Libraries
6888 GDB can now debug programs and core files that use SunOS shared libraries.
6889 Symbols from a shared library cannot be referenced
6890 before the shared library has been linked with the program (this
6891 happens after you type ``run'' and before the function main() is entered).
6892 At any time after this linking (including when examining core files
6893 from dynamically linked programs), gdb reads the symbols from each
6894 shared library when you type the ``sharedlibrary'' command.
6895 It can be abbreviated ``share''.
6897 sharedlibrary REGEXP: Load shared object library symbols for files
6898 matching a unix regular expression. No argument
6899 indicates to load symbols for all shared libraries.
6901 info sharedlibrary: Status of loaded shared libraries.
6906 A watchpoint stops execution of a program whenever the value of an
6907 expression changes. Checking for this slows down execution
6908 tremendously whenever you are in the scope of the expression, but is
6909 quite useful for catching tough ``bit-spreader'' or pointer misuse
6910 problems. Some machines such as the 386 have hardware for doing this
6911 more quickly, and future versions of gdb will use this hardware.
6913 watch EXP: Set a watchpoint (breakpoint) for an expression.
6915 info watchpoints: Information about your watchpoints.
6917 delete N: Deletes watchpoint number N (same as breakpoints).
6918 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6919 enable N: Re-enables watchpoint number N (same as breakpoints).
6922 * C++ multiple inheritance
6924 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6927 * C++ exception handling
6929 Gdb now supports limited C++ exception handling. Besides the existing
6930 ability to breakpoint on an exception handler, gdb can breakpoint on
6931 the raising of an exception (before the stack is peeled back to the
6934 catch FOO: If there is a FOO exception handler in the dynamic scope,
6935 set a breakpoint to catch exceptions which may be raised there.
6936 Multiple exceptions (``catch foo bar baz'') may be caught.
6938 info catch: Lists all exceptions which may be caught in the
6939 current stack frame.
6942 * Minor command changes
6944 The command ``call func (arg, arg, ...)'' now acts like the print
6945 command, except it does not print or save a value if the function's result
6946 is void. This is similar to dbx usage.
6948 The ``up'' and ``down'' commands now always print the frame they end up
6949 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6950 frames without printing.
6952 * New directory command
6954 'dir' now adds directories to the FRONT of the source search path.
6955 The path starts off empty. Source files that contain debug information
6956 about the directory in which they were compiled can be found even
6957 with an empty path; Sun CC and GCC include this information. If GDB can't
6958 find your source file in the current directory, type "dir .".
6960 * Configuring GDB for compilation
6962 For normal use, type ``./configure host''. See README or gdb.texinfo
6965 GDB now handles cross debugging. If you are remotely debugging between
6966 two different machines, type ``./configure host -target=targ''.
6967 Host is the machine where GDB will run; targ is the machine
6968 where the program that you are debugging will run.