1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * New "--readnever" command line option instructs GDB to not read each
7 symbol file's symbolic debug information. This makes startup faster
8 but at the expense of not being able to perform symbolic debugging.
9 This option is intended for use cases where symbolic debugging will
10 not be used, e.g., when you only need to dump the debuggee's core.
12 * GDB now uses the GNU MPFR library, if available, to emulate target
13 floating-point arithmetic during expression evaluation when the target
14 uses different floating-point formats than the host. At least version
15 3.1 of GNU MPFR is required.
17 * GDB now supports access to the guarded-storage-control registers and the
18 software-based guarded-storage broadcast control registers on IBM z14.
20 * On Unix systems, GDB now supports transmitting environment variables
21 that are to be set or unset to GDBserver. These variables will
22 affect the environment to be passed to the remote inferior.
24 To inform GDB of environment variables that are to be transmitted to
25 GDBserver, use the "set environment" command. Only user set
26 environment variables are sent to GDBserver.
28 To inform GDB of environment variables that are to be unset before
29 the remote inferior is started by the GDBserver, use the "unset
32 * Completion improvements
34 ** GDB can now complete function parameters in linespecs and
35 explicit locations without quoting. When setting breakpoints,
36 quoting around functions names to help with TAB-completion is
37 generally no longer necessary. For example, this now completes
40 (gdb) b function(in[TAB]
43 Related, GDB is no longer confused with completing functions in
44 C++ anonymous namespaces:
47 (gdb) b (anonymous namespace)::[TAB][TAB]
48 (anonymous namespace)::a_function()
49 (anonymous namespace)::b_function()
51 ** GDB now has much improved linespec and explicit locations TAB
52 completion support, that better understands what you're
53 completing and offers better suggestions. For example, GDB no
54 longer offers data symbols as possible completions when you're
57 ** GDB now TAB-completes label symbol names.
59 ** The "complete" command now mimics TAB completion accurately.
61 * New command line options (gcore)
64 Dump all memory mappings.
66 * Breakpoints on C++ functions are now set on all scopes by default
68 By default, breakpoints on functions/methods are now interpreted as
69 specifying all functions with the given name ignoring missing
70 leading scopes (namespaces and classes).
72 For example, assuming a C++ program with symbols named:
77 both commands "break func()" and "break B::func()" set a breakpoint
80 You can use the new flag "-qualified" to override this. This makes
81 GDB interpret the specified function name as a complete
82 fully-qualified name instead. For example, using the same C++
83 program, the "break -q B::func" command sets a breakpoint on
84 "B::func", only. A parameter has been added to the Python
85 gdb.Breakpoint constructor to achieve the same result when creating
86 a breakpoint from Python.
88 * Breakpoints on functions marked with C++ ABI tags
90 GDB can now set breakpoints on functions marked with C++ ABI tags
91 (e.g., [abi:cxx11]). See here for a description of ABI tags:
92 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
94 Functions with a C++11 abi tag are demangled/displayed like this:
96 function[abi:cxx11](int)
99 You can now set a breakpoint on such functions simply as if they had
102 (gdb) b function(int)
104 Or if you need to disambiguate between tags, like:
106 (gdb) b function[abi:other_tag](int)
108 Tab completion was adjusted accordingly as well.
112 ** New events gdb.new_inferior, gdb.inferior_deleted, and
113 gdb.new_thread are emitted. See the manual for further
114 description of these.
116 ** A new command, "rbreak" has been added to the Python API. This
117 command allows the setting of a large number of breakpoints via a
118 regex pattern in Python. See the manual for further details.
120 ** Python breakpoints can now accept explicit locations. See the
121 manual for a further description of this feature.
124 * New features in the GDB remote stub, GDBserver
126 ** GDBserver is now able to start inferior processes with a
127 specified initial working directory.
129 The user can set the desired working directory to be used from
130 GDB using the new "set cwd" command.
132 ** New "--selftest" command line option runs some GDBserver self
133 tests. These self tests are disabled in releases.
135 ** On Unix systems, GDBserver now does globbing expansion and variable
136 substitution in inferior command line arguments.
138 This is done by starting inferiors using a shell, like GDB does.
139 See "set startup-with-shell" in the user manual for how to disable
140 this from GDB when using "target extended-remote". When using
141 "target remote", you can disable the startup with shell by using the
142 new "--no-startup-with-shell" GDBserver command line option.
144 ** On Unix systems, GDBserver now supports receiving environment
145 variables that are to be set or unset from GDB. These variables
146 will affect the environment to be passed to the inferior.
148 * When catching an Ada exception raised with a message, GDB now prints
149 the message in the catchpoint hit notification. In GDB/MI mode, that
150 information is provided as an extra field named "exception-message"
151 in the *stopped notification.
153 * Trait objects can now be inspected When debugging Rust code. This
154 requires compiler support which will appear in Rust 1.24.
158 QEnvironmentHexEncoded
159 Inform GDBserver of an environment variable that is to be passed to
160 the inferior when starting it.
163 Inform GDBserver of an environment variable that is to be unset
164 before starting the remote inferior.
167 Inform GDBserver that the environment should be reset (i.e.,
168 user-set environment variables should be unset).
171 Indicates whether the inferior must be started with a shell or not.
174 Tell GDBserver that the inferior to be started should use a specific
177 * The "maintenance print c-tdesc" command now takes an optional
178 argument which is the file name of XML target description.
180 * The "maintenance selftest" command now takes an optional argument to
181 filter the tests to be run.
183 * The "enable", and "disable" commands now accept a range of
184 breakpoint locations, e.g. "enable 1.3-5".
189 Set and show the current working directory for the inferior.
192 Set and show compilation command used for compiling and injecting code
193 with the 'compile' commands.
195 set debug separate-debug-file
196 show debug separate-debug-file
197 Control the display of debug output about separate debug file search.
199 set dump-excluded-mappings
200 show dump-excluded-mappings
201 Control whether mappings marked with the VM_DONTDUMP flag should be
202 dumped when generating a core file.
205 List the registered selftests.
208 Start the debugged program stopping at the first instruction.
210 set|show print type nested-type-limit
211 Set and show the limit of nesting level for nested types that the
212 type printer will show.
214 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
217 * Safer/improved support for debugging with no debug info
219 GDB no longer assumes functions with no debug information return
222 This means that GDB now refuses to call such functions unless you
223 tell it the function's type, by either casting the call to the
224 declared return type, or by casting the function to a function
225 pointer of the right type, and calling that:
227 (gdb) p getenv ("PATH")
228 'getenv' has unknown return type; cast the call to its declared return type
229 (gdb) p (char *) getenv ("PATH")
230 $1 = 0x7fffffffe "/usr/local/bin:/"...
231 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
232 $2 = 0x7fffffffe "/usr/local/bin:/"...
234 Similarly, GDB no longer assumes that global variables with no debug
235 info have type 'int', and refuses to print the variable's value
236 unless you tell it the variable's type:
239 'var' has unknown type; cast it to its declared type
243 * New native configurations
245 FreeBSD/aarch64 aarch64*-*-freebsd*
246 FreeBSD/arm arm*-*-freebsd*
250 FreeBSD/aarch64 aarch64*-*-freebsd*
251 FreeBSD/arm arm*-*-freebsd*
253 * Removed targets and native configurations
255 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
257 *** Changes in GDB 8.0
259 * GDB now supports access to the PKU register on GNU/Linux. The register is
260 added by the Memory Protection Keys for Userspace feature which will be
261 available in future Intel CPUs.
263 * GDB now supports C++11 rvalue references.
267 ** New functions to start, stop and access a running btrace recording.
268 ** Rvalue references are now supported in gdb.Type.
270 * GDB now supports recording and replaying rdrand and rdseed Intel 64
273 * Building GDB and GDBserver now requires a C++11 compiler.
275 For example, GCC 4.8 or later.
277 It is no longer possible to build GDB or GDBserver with a C
278 compiler. The --disable-build-with-cxx configure option has been
281 * Building GDB and GDBserver now requires GNU make >= 3.81.
283 It is no longer supported to build GDB or GDBserver with another
284 implementation of the make program or an earlier version of GNU make.
286 * Native debugging on MS-Windows supports command-line redirection
288 Command-line arguments used for starting programs on MS-Windows can
289 now include redirection symbols supported by native Windows shells,
290 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
291 as "run", "start", and "set args", as well as the corresponding MI
294 * Support for thread names on MS-Windows.
296 GDB now catches and handles the special exception that programs
297 running on MS-Windows use to assign names to threads in the
300 * Support for Java programs compiled with gcj has been removed.
302 * User commands now accept an unlimited number of arguments.
303 Previously, only up to 10 was accepted.
305 * The "eval" command now expands user-defined command arguments.
307 This makes it easier to process a variable number of arguments:
312 eval "print $arg%d", $i
317 * Target descriptions can now describe registers for sparc32 and sparc64.
319 * GDB now supports DWARF version 5 (debug information format).
320 Its .debug_names index is not yet supported.
322 * New native configurations
324 FreeBSD/mips mips*-*-freebsd
328 Synopsys ARC arc*-*-elf32
329 FreeBSD/mips mips*-*-freebsd
331 * Removed targets and native configurations
333 Alpha running FreeBSD alpha*-*-freebsd*
334 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
339 Erases all the flash memory regions reported by the target.
341 maint print arc arc-instruction address
342 Print internal disassembler information about instruction at a given address.
346 set disassembler-options
347 show disassembler-options
348 Controls the passing of target specific information to the disassembler.
349 If it is necessary to specify more than one disassembler option then
350 multiple options can be placed together into a comma separated list.
351 The default value is the empty string. Currently, the only supported
352 targets are ARM, PowerPC and S/390.
357 Erases all the flash memory regions reported by the target. This is
358 equivalent to the CLI command flash-erase.
360 -file-list-shared-libraries
361 List the shared libraries in the program. This is
362 equivalent to the CLI command "info shared".
364 *** Changes in GDB 7.12
366 * GDB and GDBserver now build with a C++ compiler by default.
368 The --enable-build-with-cxx configure option is now enabled by
369 default. One must now explicitly configure with
370 --disable-build-with-cxx in order to build with a C compiler. This
371 option will be removed in a future release.
373 * GDBserver now supports recording btrace without maintaining an active
376 * GDB now supports a negative repeat count in the 'x' command to examine
377 memory backward from the given address. For example:
380 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
381 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
382 (gdb) x/-5i 0x0000000000400580
383 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
384 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
385 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
386 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
387 0x40057b <main(int, char**)+25>:
388 callq 0x400536 <Func1(int, char const*)>
390 * Fortran: Support structures with fields of dynamic types and
391 arrays of dynamic types.
393 * The symbol dumping maintenance commands have new syntax.
394 maint print symbols [-pc address] [--] [filename]
395 maint print symbols [-objfile objfile] [-source source] [--] [filename]
396 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
397 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
398 maint print msymbols [-objfile objfile] [--] [filename]
400 * GDB now supports multibit bitfields and enums in target register
403 * New Python-based convenience function $_as_string(val), which returns
404 the textual representation of a value. This function is especially
405 useful to obtain the text label of an enum value.
407 * Intel MPX bound violation handling.
409 Segmentation faults caused by a Intel MPX boundary violation
410 now display the kind of violation (upper or lower), the memory
411 address accessed and the memory bounds, along with the usual
412 signal received and code location.
416 Program received signal SIGSEGV, Segmentation fault
417 Upper bound violation while accessing address 0x7fffffffc3b3
418 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
419 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
421 * Rust language support.
422 GDB now supports debugging programs written in the Rust programming
423 language. See https://www.rust-lang.org/ for more information about
426 * Support for running interpreters on specified input/output devices
428 GDB now supports a new mechanism that allows frontends to provide
429 fully featured GDB console views, as a better alternative to
430 building such views on top of the "-interpreter-exec console"
431 command. See the new "new-ui" command below. With that command,
432 frontends can now start GDB in the traditional command-line mode
433 running in an embedded terminal emulator widget, and create a
434 separate MI interpreter running on a specified i/o device. In this
435 way, GDB handles line editing, history, tab completion, etc. in the
436 console all by itself, and the GUI uses the separate MI interpreter
437 for its own control and synchronization, invisible to the command
440 * The "catch syscall" command catches groups of related syscalls.
442 The "catch syscall" command now supports catching a group of related
443 syscalls using the 'group:' or 'g:' prefix.
448 skip -gfile file-glob-pattern
449 skip -function function
450 skip -rfunction regular-expression
451 A generalized form of the skip command, with new support for
452 glob-style file names and regular expressions for function names.
453 Additionally, a file spec and a function spec may now be combined.
455 maint info line-table REGEXP
456 Display the contents of GDB's internal line table data struture.
459 Run any GDB unit tests that were compiled in.
462 Start a new user interface instance running INTERP as interpreter,
463 using the TTY file for input/output.
467 ** gdb.Breakpoint objects have a new attribute "pending", which
468 indicates whether the breakpoint is pending.
469 ** Three new breakpoint-related events have been added:
470 gdb.breakpoint_created, gdb.breakpoint_modified, and
471 gdb.breakpoint_deleted.
474 Signal ("set") the given MS-Windows event object. This is used in
475 conjunction with the Windows JIT debugging (AeDebug) support, where
476 the OS suspends a crashing process until a debugger can attach to
477 it. Resuming the crashing process, in order to debug it, is done by
480 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
481 was added in GDBserver, including JIT compiling fast tracepoint's
482 conditional expression bytecode into native code.
484 * Support for various remote target protocols and ROM monitors has
487 target m32rsdi Remote M32R debugging over SDI
488 target mips MIPS remote debugging protocol
489 target pmon PMON ROM monitor
490 target ddb NEC's DDB variant of PMON for Vr4300
491 target rockhopper NEC RockHopper variant of PMON
492 target lsi LSI variant of PMO
494 * Support for tracepoints and fast tracepoints on powerpc-linux,
495 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
496 including JIT compiling fast tracepoint's conditional expression
497 bytecode into native code.
499 * MI async record =record-started now includes the method and format used for
500 recording. For example:
502 =record-started,thread-group="i1",method="btrace",format="bts"
504 * MI async record =thread-selected now includes the frame field. For example:
506 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
510 Andes NDS32 nds32*-*-elf
512 *** Changes in GDB 7.11
514 * GDB now supports debugging kernel-based threads on FreeBSD.
516 * Per-inferior thread numbers
518 Thread numbers are now per inferior instead of global. If you're
519 debugging multiple inferiors, GDB displays thread IDs using a
520 qualified INF_NUM.THR_NUM form. For example:
524 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
525 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
526 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
527 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
529 As consequence, thread numbers as visible in the $_thread
530 convenience variable and in Python's InferiorThread.num attribute
531 are no longer unique between inferiors.
533 GDB now maintains a second thread ID per thread, referred to as the
534 global thread ID, which is the new equivalent of thread numbers in
535 previous releases. See also $_gthread below.
537 For backwards compatibility, MI's thread IDs always refer to global
540 * Commands that accept thread IDs now accept the qualified
541 INF_NUM.THR_NUM form as well. For example:
544 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
547 * In commands that accept a list of thread IDs, you can now refer to
548 all threads of an inferior using a star wildcard. GDB accepts
549 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
550 refer to all threads of the current inferior. For example, "info
553 * You can use "info threads -gid" to display the global thread ID of
556 * The new convenience variable $_gthread holds the global number of
559 * The new convenience variable $_inferior holds the number of the
562 * GDB now displays the ID and name of the thread that hit a breakpoint
563 or received a signal, if your program is multi-threaded. For
566 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
567 Thread 1 "main" received signal SIGINT, Interrupt.
569 * Record btrace now supports non-stop mode.
571 * Support for tracepoints on aarch64-linux was added in GDBserver.
573 * The 'record instruction-history' command now indicates speculative execution
574 when using the Intel Processor Trace recording format.
576 * GDB now allows users to specify explicit locations, bypassing
577 the linespec parser. This feature is also available to GDB/MI
580 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
581 GDB now is able to debug both AArch64 applications and ARM applications
584 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
585 including JIT compiling fast tracepoint's conditional expression bytecode
588 * GDB now supports displaced stepping on AArch64 GNU/Linux.
590 * "info threads", "info inferiors", "info display", "info checkpoints"
591 and "maint info program-spaces" now list the corresponding items in
592 ascending ID order, for consistency with all other "info" commands.
594 * In Ada, the overloads selection menu has been enhanced to display the
595 parameter types and the return types for the matching overloaded subprograms.
599 maint set target-non-stop (on|off|auto)
600 maint show target-non-stop
601 Control whether GDB targets always operate in non-stop mode even if
602 "set non-stop" is "off". The default is "auto", meaning non-stop
603 mode is enabled if supported by the target.
605 maint set bfd-sharing
606 maint show bfd-sharing
607 Control the reuse of bfd objects.
611 Control display of debugging info regarding bfd caching.
615 Control display of debugging info regarding FreeBSD threads.
617 set remote multiprocess-extensions-packet
618 show remote multiprocess-extensions-packet
619 Set/show the use of the remote protocol multiprocess extensions.
621 set remote thread-events
622 show remote thread-events
623 Set/show the use of thread create/exit events.
625 set ada print-signatures on|off
626 show ada print-signatures"
627 Control whether parameter types and return types are displayed in overloads
628 selection menus. It is activaled (@code{on}) by default.
632 Controls the maximum size of memory, in bytes, that GDB will
633 allocate for value contents. Prevents incorrect programs from
634 causing GDB to allocate overly large buffers. Default is 64k.
636 * The "disassemble" command accepts a new modifier: /s.
637 It prints mixed source+disassembly like /m with two differences:
638 - disassembled instructions are now printed in program order, and
639 - and source for all relevant files is now printed.
640 The "/m" option is now considered deprecated: its "source-centric"
641 output hasn't proved useful in practice.
643 * The "record instruction-history" command accepts a new modifier: /s.
644 It behaves exactly like /m and prints mixed source+disassembly.
646 * The "set scheduler-locking" command supports a new mode "replay".
647 It behaves like "off" in record mode and like "on" in replay mode.
649 * Support for various ROM monitors has been removed:
651 target dbug dBUG ROM monitor for Motorola ColdFire
652 target picobug Motorola picobug monitor
653 target dink32 DINK32 ROM monitor for PowerPC
654 target m32r Renesas M32R/D ROM monitor
655 target mon2000 mon2000 ROM monitor
656 target ppcbug PPCBUG ROM monitor for PowerPC
658 * Support for reading/writing memory and extracting values on architectures
659 whose memory is addressable in units of any integral multiple of 8 bits.
664 Indicates that an exec system call was executed.
666 exec-events feature in qSupported
667 The qSupported packet allows GDB to request support for exec
668 events using the new 'gdbfeature' exec-event, and the qSupported
669 response can contain the corresponding 'stubfeature'. Set and
670 show commands can be used to display whether these features are enabled.
673 Equivalent to interrupting with the ^C character, but works in
676 thread created stop reason (T05 create:...)
677 Indicates that the thread was just created and is stopped at entry.
679 thread exit stop reply (w exitcode;tid)
680 Indicates that the thread has terminated.
683 Enables/disables thread create and exit event reporting. For
684 example, this is used in non-stop mode when GDB stops a set of
685 threads and synchronously waits for the their corresponding stop
686 replies. Without exit events, if one of the threads exits, GDB
687 would hang forever not knowing that it should no longer expect a
688 stop for that same thread.
691 Indicates that there are no resumed threads left in the target (all
692 threads are stopped). The remote stub reports support for this stop
693 reply to GDB's qSupported query.
696 Enables/disables catching syscalls from the inferior process.
697 The remote stub reports support for this packet to GDB's qSupported query.
699 syscall_entry stop reason
700 Indicates that a syscall was just called.
702 syscall_return stop reason
703 Indicates that a syscall just returned.
705 * Extended-remote exec events
707 ** GDB now has support for exec events on extended-remote Linux targets.
708 For such targets with Linux kernels 2.5.46 and later, this enables
709 follow-exec-mode and exec catchpoints.
711 set remote exec-event-feature-packet
712 show remote exec-event-feature-packet
713 Set/show the use of the remote exec event feature.
715 * Thread names in remote protocol
717 The reply to qXfer:threads:read may now include a name attribute for each
720 * Target remote mode fork and exec events
722 ** GDB now has support for fork and exec events on target remote mode
723 Linux targets. For such targets with Linux kernels 2.5.46 and later,
724 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
725 fork and exec catchpoints.
727 * Remote syscall events
729 ** GDB now has support for catch syscall on remote Linux targets,
730 currently enabled on x86/x86_64 architectures.
732 set remote catch-syscall-packet
733 show remote catch-syscall-packet
734 Set/show the use of the remote catch syscall feature.
738 ** The -var-set-format command now accepts the zero-hexadecimal
739 format. It outputs data in hexadecimal format with zero-padding on the
744 ** gdb.InferiorThread objects have a new attribute "global_num",
745 which refers to the thread's global thread ID. The existing
746 "num" attribute now refers to the thread's per-inferior number.
747 See "Per-inferior thread numbers" above.
748 ** gdb.InferiorThread objects have a new attribute "inferior", which
749 is the Inferior object the thread belongs to.
751 *** Changes in GDB 7.10
753 * Support for process record-replay and reverse debugging on aarch64*-linux*
754 targets has been added. GDB now supports recording of A64 instruction set
755 including advance SIMD instructions.
757 * Support for Sun's version of the "stabs" debug file format has been removed.
759 * GDB now honors the content of the file /proc/PID/coredump_filter
760 (PID is the process ID) on GNU/Linux systems. This file can be used
761 to specify the types of memory mappings that will be included in a
762 corefile. For more information, please refer to the manual page of
763 "core(5)". GDB also has a new command: "set use-coredump-filter
764 on|off". It allows to set whether GDB will read the content of the
765 /proc/PID/coredump_filter file when generating a corefile.
767 * The "info os" command on GNU/Linux can now display information on
769 "info os cpus" Listing of all cpus/cores on the system
771 * GDB has two new commands: "set serial parity odd|even|none" and
772 "show serial parity". These allows to set or show parity for the
775 * The "info source" command now displays the producer string if it was
776 present in the debug info. This typically includes the compiler version
777 and may include things like its command line arguments.
779 * The "info dll", an alias of the "info sharedlibrary" command,
780 is now available on all platforms.
782 * Directory names supplied to the "set sysroot" commands may be
783 prefixed with "target:" to tell GDB to access shared libraries from
784 the target system, be it local or remote. This replaces the prefix
785 "remote:". The default sysroot has been changed from "" to
786 "target:". "remote:" is automatically converted to "target:" for
787 backward compatibility.
789 * The system root specified by "set sysroot" will be prepended to the
790 filename of the main executable (if reported to GDB as absolute by
791 the operating system) when starting processes remotely, and when
792 attaching to already-running local or remote processes.
794 * GDB now supports automatic location and retrieval of executable
795 files from remote targets. Remote debugging can now be initiated
796 using only a "target remote" or "target extended-remote" command
797 (no "set sysroot" or "file" commands are required). See "New remote
800 * The "dump" command now supports verilog hex format.
802 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
804 * On GNU/Linux, GDB and gdbserver are now able to access executable
805 and shared library files without a "set sysroot" command when
806 attaching to processes running in different mount namespaces from
807 the debugger. This makes it possible to attach to processes in
808 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
809 See "New remote packets" below.
811 * The "tui reg" command now provides completion for all of the
812 available register groups, including target specific groups.
814 * The HISTSIZE environment variable is no longer read when determining
815 the size of GDB's command history. GDB now instead reads the dedicated
816 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
817 disables truncation of command history. Non-numeric values of GDBHISTSIZE
822 ** Memory ports can now be unbuffered.
826 ** gdb.Objfile objects have a new attribute "username",
827 which is the name of the objfile as specified by the user,
828 without, for example, resolving symlinks.
829 ** You can now write frame unwinders in Python.
830 ** gdb.Type objects have a new method "optimized_out",
831 returning optimized out gdb.Value instance of this type.
832 ** gdb.Value objects have new methods "reference_value" and
833 "const_value" which return a reference to the value and a
834 "const" version of the value respectively.
838 maint print symbol-cache
839 Print the contents of the symbol cache.
841 maint print symbol-cache-statistics
842 Print statistics of symbol cache usage.
844 maint flush-symbol-cache
845 Flush the contents of the symbol cache.
849 Start branch trace recording using Branch Trace Store (BTS) format.
852 Evaluate expression by using the compiler and print result.
856 Explicit commands for enabling and disabling tui mode.
859 set mpx bound on i386 and amd64
860 Support for bound table investigation on Intel MPX enabled applications.
864 Start branch trace recording using Intel Processor Trace format.
867 Print information about branch tracing internals.
869 maint btrace packet-history
870 Print the raw branch tracing data.
872 maint btrace clear-packet-history
873 Discard the stored raw branch tracing data.
876 Discard all branch tracing data. It will be fetched and processed
877 anew by the next "record" command.
882 Renamed from "set debug dwarf2-die".
884 Renamed from "show debug dwarf2-die".
887 Renamed from "set debug dwarf2-read".
888 show debug dwarf-read
889 Renamed from "show debug dwarf2-read".
891 maint set dwarf always-disassemble
892 Renamed from "maint set dwarf2 always-disassemble".
893 maint show dwarf always-disassemble
894 Renamed from "maint show dwarf2 always-disassemble".
896 maint set dwarf max-cache-age
897 Renamed from "maint set dwarf2 max-cache-age".
898 maint show dwarf max-cache-age
899 Renamed from "maint show dwarf2 max-cache-age".
902 show debug dwarf-line
903 Control display of debugging info regarding DWARF line processing.
907 Set the maximum number of candidates to be considered during
908 completion. The default value is 200. This limit allows GDB
909 to avoid generating large completion lists, the computation of
910 which can cause the debugger to become temporarily unresponsive.
912 set history remove-duplicates
913 show history remove-duplicates
914 Control the removal of duplicate history entries.
916 maint set symbol-cache-size
917 maint show symbol-cache-size
918 Control the size of the symbol cache.
920 set|show record btrace bts buffer-size
921 Set and show the size of the ring buffer used for branch tracing in
923 The obtained size may differ from the requested size. Use "info
924 record" to see the obtained buffer size.
926 set debug linux-namespaces
927 show debug linux-namespaces
928 Control display of debugging info regarding Linux namespaces.
930 set|show record btrace pt buffer-size
931 Set and show the size of the ring buffer used for branch tracing in
932 Intel Processor Trace format.
933 The obtained size may differ from the requested size. Use "info
934 record" to see the obtained buffer size.
936 maint set|show btrace pt skip-pad
937 Set and show whether PAD packets are skipped when computing the
940 * The command 'thread apply all' can now support new option '-ascending'
941 to call its specified command for all threads in ascending order.
943 * Python/Guile scripting
945 ** GDB now supports auto-loading of Python/Guile scripts contained in the
946 special section named `.debug_gdb_scripts'.
950 qXfer:btrace-conf:read
951 Return the branch trace configuration for the current thread.
953 Qbtrace-conf:bts:size
954 Set the requested ring buffer size for branch tracing in BTS format.
957 Enable Intel Procesor Trace-based branch tracing for the current
958 process. The remote stub reports support for this packet to GDB's
962 Set the requested ring buffer size for branch tracing in Intel Processor
966 Indicates a memory breakpoint instruction was executed, irrespective
967 of whether it was GDB that planted the breakpoint or the breakpoint
968 is hardcoded in the program. This is required for correct non-stop
972 Indicates the target stopped for a hardware breakpoint. This is
973 required for correct non-stop mode operation.
976 Return information about files on the remote system.
979 Return the full absolute name of the file that was executed to
980 create a process running on the remote system.
983 Select the filesystem on which vFile: operations with filename
984 arguments will operate. This is required for GDB to be able to
985 access files on remote targets where the remote stub does not
986 share a common filesystem with the inferior(s).
989 Indicates that a fork system call was executed.
992 Indicates that a vfork system call was executed.
994 vforkdone stop reason
995 Indicates that a vfork child of the specified process has executed
996 an exec or exit, allowing the vfork parent to resume execution.
998 fork-events and vfork-events features in qSupported
999 The qSupported packet allows GDB to request support for fork and
1000 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1001 and the qSupported response can contain the corresponding
1002 'stubfeatures'. Set and show commands can be used to display
1003 whether these features are enabled.
1005 * Extended-remote fork events
1007 ** GDB now has support for fork events on extended-remote Linux
1008 targets. For targets with Linux kernels 2.5.60 and later, this
1009 enables follow-fork-mode and detach-on-fork for both fork and
1010 vfork, as well as fork and vfork catchpoints.
1012 * The info record command now shows the recording format and the
1013 branch tracing configuration for the current thread when using
1014 the btrace record target.
1015 For the BTS format, it shows the ring buffer size.
1017 * GDB now has support for DTrace USDT (Userland Static Defined
1018 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1020 * GDB now supports access to vector registers on S/390 GNU/Linux
1023 * Removed command line options
1025 -xdb HP-UX XDB compatibility mode.
1027 * Removed targets and native configurations
1029 HP/PA running HP-UX hppa*-*-hpux*
1030 Itanium running HP-UX ia64-*-hpux*
1032 * New configure options
1035 This configure option allows the user to build GDB with support for
1036 Intel Processor Trace (default: auto). This requires libipt.
1038 --with-libipt-prefix=PATH
1039 Specify the path to the version of libipt that GDB should use.
1040 $PATH/include should contain the intel-pt.h header and
1041 $PATH/lib should contain the libipt.so library.
1043 *** Changes in GDB 7.9.1
1047 ** Xmethods can now specify a result type.
1049 *** Changes in GDB 7.9
1051 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1055 ** You can now access frame registers from Python scripts.
1056 ** New attribute 'producer' for gdb.Symtab objects.
1057 ** gdb.Objfile objects have a new attribute "progspace",
1058 which is the gdb.Progspace object of the containing program space.
1059 ** gdb.Objfile objects have a new attribute "owner".
1060 ** gdb.Objfile objects have a new attribute "build_id",
1061 which is the build ID generated when the file was built.
1062 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1063 ** A new event "gdb.clear_objfiles" has been added, triggered when
1064 selecting a new file to debug.
1065 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1066 ** New function gdb.lookup_objfile.
1068 New events which are triggered when GDB modifies the state of the
1071 ** gdb.events.inferior_call_pre: Function call is about to be made.
1072 ** gdb.events.inferior_call_post: Function call has just been made.
1073 ** gdb.events.memory_changed: A memory location has been altered.
1074 ** gdb.events.register_changed: A register has been altered.
1076 * New Python-based convenience functions:
1078 ** $_caller_is(name [, number_of_frames])
1079 ** $_caller_matches(regexp [, number_of_frames])
1080 ** $_any_caller_is(name [, number_of_frames])
1081 ** $_any_caller_matches(regexp [, number_of_frames])
1083 * GDB now supports the compilation and injection of source code into
1084 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1085 to compile the source code to object code, and if successful, inject
1086 and execute that code within the current context of the inferior.
1087 Currently the C language is supported. The commands used to
1088 interface with this new feature are:
1090 compile code [-raw|-r] [--] [source code]
1091 compile file [-raw|-r] filename
1095 demangle [-l language] [--] name
1096 Demangle "name" in the specified language, or the current language
1097 if elided. This command is renamed from the "maint demangle" command.
1098 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1099 as "maint demangler-warning".
1101 queue-signal signal-name-or-number
1102 Queue a signal to be delivered to the thread when it is resumed.
1104 add-auto-load-scripts-directory directory
1105 Add entries to the list of directories from which to load auto-loaded
1108 maint print user-registers
1109 List all currently available "user" registers.
1111 compile code [-r|-raw] [--] [source code]
1112 Compile, inject, and execute in the inferior the executable object
1113 code produced by compiling the provided source code.
1115 compile file [-r|-raw] filename
1116 Compile and inject into the inferior the executable object code
1117 produced by compiling the source code stored in the filename
1120 * On resume, GDB now always passes the signal the program had stopped
1121 for to the thread the signal was sent to, even if the user changed
1122 threads before resuming. Previously GDB would often (but not
1123 always) deliver the signal to the thread that happens to be current
1126 * Conversely, the "signal" command now consistently delivers the
1127 requested signal to the current thread. GDB now asks for
1128 confirmation if the program had stopped for a signal and the user
1129 switched threads meanwhile.
1131 * "breakpoint always-inserted" modes "off" and "auto" merged.
1133 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1134 won't remove breakpoints from the target until all threads stop,
1135 even in non-stop mode. The "auto" mode has been removed, and "off"
1136 is now the default mode.
1140 set debug symbol-lookup
1141 show debug symbol-lookup
1142 Control display of debugging info regarding symbol lookup.
1146 ** The -list-thread-groups command outputs an exit-code field for
1147 inferiors that have exited.
1151 MIPS SDE mips*-sde*-elf*
1155 Support for these obsolete configurations has been removed.
1157 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1158 SGI Irix-5.x mips-*-irix5*
1159 SGI Irix-6.x mips-*-irix6*
1160 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1161 VAX running Ultrix vax-*-ultrix*
1163 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1164 and "assf"), have been removed. Use the "sharedlibrary" command, or
1165 its alias "share", instead.
1167 *** Changes in GDB 7.8
1169 * New command line options
1172 This is an alias for the --data-directory option.
1174 * GDB supports printing and modifying of variable length automatic arrays
1175 as specified in ISO C99.
1177 * The ARM simulator now supports instruction level tracing
1178 with or without disassembly.
1182 GDB now has support for scripting using Guile. Whether this is
1183 available is determined at configure time.
1184 Guile version 2.0 or greater is required.
1185 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1187 * New commands (for set/show, see "New options" below)
1191 Invoke CODE by passing it to the Guile interpreter.
1195 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1197 info auto-load guile-scripts [regexp]
1198 Print the list of automatically loaded Guile scripts.
1200 * The source command is now capable of sourcing Guile scripts.
1201 This feature is dependent on the debugger being built with Guile support.
1205 set print symbol-loading (off|brief|full)
1206 show print symbol-loading
1207 Control whether to print informational messages when loading symbol
1208 information for a file. The default is "full", but when debugging
1209 programs with large numbers of shared libraries the amount of output
1210 becomes less useful.
1212 set guile print-stack (none|message|full)
1213 show guile print-stack
1214 Show a stack trace when an error is encountered in a Guile script.
1216 set auto-load guile-scripts (on|off)
1217 show auto-load guile-scripts
1218 Control auto-loading of Guile script files.
1220 maint ada set ignore-descriptive-types (on|off)
1221 maint ada show ignore-descriptive-types
1222 Control whether the debugger should ignore descriptive types in Ada
1223 programs. The default is not to ignore the descriptive types. See
1224 the user manual for more details on descriptive types and the intended
1225 usage of this option.
1227 set auto-connect-native-target
1229 Control whether GDB is allowed to automatically connect to the
1230 native target for the run, attach, etc. commands when not connected
1231 to any target yet. See also "target native" below.
1233 set record btrace replay-memory-access (read-only|read-write)
1234 show record btrace replay-memory-access
1235 Control what memory accesses are allowed during replay.
1237 maint set target-async (on|off)
1238 maint show target-async
1239 This controls whether GDB targets operate in synchronous or
1240 asynchronous mode. Normally the default is asynchronous, if it is
1241 available; but this can be changed to more easily debug problems
1242 occurring only in synchronous mode.
1244 set mi-async (on|off)
1246 Control whether MI asynchronous mode is preferred. This supersedes
1247 "set target-async" of previous GDB versions.
1249 * "set target-async" is deprecated as a CLI option and is now an alias
1250 for "set mi-async" (only puts MI into async mode).
1252 * Background execution commands (e.g., "c&", "s&", etc.) are now
1253 possible ``out of the box'' if the target supports them. Previously
1254 the user would need to explicitly enable the possibility with the
1255 "set target-async on" command.
1257 * New features in the GDB remote stub, GDBserver
1259 ** New option --debug-format=option1[,option2,...] allows one to add
1260 additional text to each output. At present only timestamps
1261 are supported: --debug-format=timestamps.
1262 Timestamps can also be turned on with the
1263 "monitor set debug-format timestamps" command from GDB.
1265 * The 'record instruction-history' command now starts counting instructions
1266 at one. This also affects the instruction ranges reported by the
1267 'record function-call-history' command when given the /i modifier.
1269 * The command 'record function-call-history' supports a new modifier '/c' to
1270 indent the function names based on their call stack depth.
1271 The fields for the '/i' and '/l' modifier have been reordered.
1272 The source line range is now prefixed with 'at'.
1273 The instruction range is now prefixed with 'inst'.
1274 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1275 "record instruction-history" and "list" commands.
1277 * The ranges given as arguments to the 'record function-call-history' and
1278 'record instruction-history' commands are now inclusive.
1280 * The btrace record target now supports the 'record goto' command.
1281 For locations inside the execution trace, the back trace is computed
1282 based on the information stored in the execution trace.
1284 * The btrace record target supports limited reverse execution and replay.
1285 The target does not record data and therefore does not allow reading
1286 memory or registers.
1288 * The "catch syscall" command now works on s390*-linux* targets.
1290 * The "compare-sections" command is no longer specific to target
1291 remote. It now works with all targets.
1293 * All native targets are now consistently called "native".
1294 Consequently, the "target child", "target GNU", "target djgpp",
1295 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1296 commands have been replaced with "target native". The QNX/NTO port
1297 leaves the "procfs" target in place and adds a "native" target for
1298 consistency with other ports. The impact on users should be minimal
1299 as these commands previously either throwed an error, or were
1300 no-ops. The target's name is visible in the output of the following
1301 commands: "help target", "info target", "info files", "maint print
1304 * The "target native" command now connects to the native target. This
1305 can be used to launch native programs even when "set
1306 auto-connect-native-target" is set to off.
1308 * GDB now supports access to Intel MPX registers on GNU/Linux.
1310 * Support for Intel AVX-512 registers on GNU/Linux.
1311 Support displaying and modifying Intel AVX-512 registers
1312 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1314 * New remote packets
1316 qXfer:btrace:read's annex
1317 The qXfer:btrace:read packet supports a new annex 'delta' to read
1318 branch trace incrementally.
1322 ** Valid Python operations on gdb.Value objects representing
1323 structs/classes invoke the corresponding overloaded operators if
1325 ** New `Xmethods' feature in the Python API. Xmethods are
1326 additional methods or replacements for existing methods of a C++
1327 class. This feature is useful for those cases where a method
1328 defined in C++ source code could be inlined or optimized out by
1329 the compiler, making it unavailable to GDB.
1332 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1334 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1335 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1336 its alias "share", instead.
1338 * The commands "set remotebaud" and "show remotebaud" are no longer
1339 supported. Use "set serial baud" and "show serial baud" (respectively)
1344 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1345 target-async". The latter is left as a deprecated alias of the
1346 former for backward compatibility. If the target supports it,
1347 CLI background execution commands are now always possible by
1348 default, independently of whether the frontend stated a
1349 preference for asynchronous execution with "-gdb-set mi-async".
1350 Previously "-gdb-set target-async off" affected both MI execution
1351 commands and CLI execution commands.
1353 *** Changes in GDB 7.7
1355 * Improved support for process record-replay and reverse debugging on
1356 arm*-linux* targets. Support for thumb32 and syscall instruction
1357 recording has been added.
1359 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1361 * GDB now supports Fission DWP file format version 2.
1362 http://gcc.gnu.org/wiki/DebugFission
1364 * New convenience function "$_isvoid", to check whether an expression
1365 is void. A void expression is an expression where the type of the
1366 result is "void". For example, some convenience variables may be
1367 "void" when evaluated (e.g., "$_exitcode" before the execution of
1368 the program being debugged; or an undefined convenience variable).
1369 Another example, when calling a function whose return type is
1372 * The "maintenance print objfiles" command now takes an optional regexp.
1374 * The "catch syscall" command now works on arm*-linux* targets.
1376 * GDB now consistently shows "<not saved>" when printing values of
1377 registers the debug info indicates have not been saved in the frame
1378 and there's nowhere to retrieve them from
1379 (callee-saved/call-clobbered registers):
1384 (gdb) info registers rax
1387 Before, the former would print "<optimized out>", and the latter
1388 "*value not available*".
1390 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1395 ** Frame filters and frame decorators have been added.
1396 ** Temporary breakpoints are now supported.
1397 ** Line tables representation has been added.
1398 ** New attribute 'parent_type' for gdb.Field objects.
1399 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1400 ** New attribute 'name' for gdb.Type objects.
1404 Nios II ELF nios2*-*-elf
1405 Nios II GNU/Linux nios2*-*-linux
1406 Texas Instruments MSP430 msp430*-*-elf
1408 * Removed native configurations
1410 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1411 been removed. ELF variants of these configurations are kept supported.
1413 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1414 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1415 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1416 i[34567]86-*-openbsd3.[0-3]
1417 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1418 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1419 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1423 Like "catch throw", but catches a re-thrown exception.
1424 maint check-psymtabs
1425 Renamed from old "maint check-symtabs".
1427 Perform consistency checks on symtabs.
1428 maint expand-symtabs
1429 Expand symtabs matching an optional regexp.
1432 Display the details of GDB configure-time options.
1434 maint set|show per-command
1435 maint set|show per-command space
1436 maint set|show per-command time
1437 maint set|show per-command symtab
1438 Enable display of per-command gdb resource usage.
1440 remove-symbol-file FILENAME
1441 remove-symbol-file -a ADDRESS
1442 Remove a symbol file added via add-symbol-file. The file to remove
1443 can be identified by its filename or by an address that lies within
1444 the boundaries of this symbol file in memory.
1447 info exceptions REGEXP
1448 Display the list of Ada exceptions defined in the program being
1449 debugged. If provided, only the exceptions whose names match REGEXP
1454 set debug symfile off|on
1456 Control display of debugging info regarding reading symbol files and
1457 symbol tables within those files
1459 set print raw frame-arguments
1460 show print raw frame-arguments
1461 Set/show whether to print frame arguments in raw mode,
1462 disregarding any defined pretty-printers.
1464 set remote trace-status-packet
1465 show remote trace-status-packet
1466 Set/show the use of remote protocol qTStatus packet.
1470 Control display of debugging messages related to Nios II targets.
1474 Control whether target-assisted range stepping is enabled.
1476 set startup-with-shell
1477 show startup-with-shell
1478 Specifies whether Unix child processes are started via a shell or
1483 Use the target memory cache for accesses to the code segment. This
1484 improves performance of remote debugging (particularly disassembly).
1486 * You can now use a literal value 'unlimited' for options that
1487 interpret 0 or -1 as meaning "unlimited". E.g., "set
1488 trace-buffer-size unlimited" is now an alias for "set
1489 trace-buffer-size -1" and "set height unlimited" is now an alias for
1492 * The "set debug symtab-create" debugging option of GDB has been changed to
1493 accept a verbosity level. 0 means "off", 1 provides basic debugging
1494 output, and values of 2 or greater provides more verbose output.
1496 * New command-line options
1498 Display the details of GDB configure-time options.
1500 * The command 'tsave' can now support new option '-ctf' to save trace
1501 buffer in Common Trace Format.
1503 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1506 * GDB now implements the the C++ 'typeid' operator.
1508 * The new convenience variable $_exception holds the exception being
1509 thrown or caught at an exception-related catchpoint.
1511 * The exception-related catchpoints, like "catch throw", now accept a
1512 regular expression which can be used to filter exceptions by type.
1514 * The new convenience variable $_exitsignal is automatically set to
1515 the terminating signal number when the program being debugged dies
1516 due to an uncaught signal.
1520 ** All MI commands now accept an optional "--language" option.
1521 Support for this feature can be verified by using the "-list-features"
1522 command, which should contain "language-option".
1524 ** The new command -info-gdb-mi-command allows the user to determine
1525 whether a GDB/MI command is supported or not.
1527 ** The "^error" result record returned when trying to execute an undefined
1528 GDB/MI command now provides a variable named "code" whose content is the
1529 "undefined-command" error code. Support for this feature can be verified
1530 by using the "-list-features" command, which should contain
1531 "undefined-command-error-code".
1533 ** The -trace-save MI command can optionally save trace buffer in Common
1536 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1538 ** The command -data-list-register-values now accepts an optional
1539 "--skip-unavailable" option. When used, only the available registers
1542 ** The new command -trace-frame-collected dumps collected variables,
1543 computed expressions, tvars, memory and registers in a traceframe.
1545 ** The commands -stack-list-locals, -stack-list-arguments and
1546 -stack-list-variables now accept an option "--skip-unavailable".
1547 When used, only the available locals or arguments are displayed.
1549 ** The -exec-run command now accepts an optional "--start" option.
1550 When used, the command follows the same semantics as the "start"
1551 command, stopping the program's execution at the start of its
1552 main subprogram. Support for this feature can be verified using
1553 the "-list-features" command, which should contain
1554 "exec-run-start-option".
1556 ** The new commands -catch-assert and -catch-exceptions insert
1557 catchpoints stopping the program when Ada exceptions are raised.
1559 ** The new command -info-ada-exceptions provides the equivalent of
1560 the new "info exceptions" command.
1562 * New system-wide configuration scripts
1563 A GDB installation now provides scripts suitable for use as system-wide
1564 configuration scripts for the following systems:
1568 * GDB now supports target-assigned range stepping with remote targets.
1569 This improves the performance of stepping source lines by reducing
1570 the number of control packets from/to GDB. See "New remote packets"
1573 * GDB now understands the element 'tvar' in the XML traceframe info.
1574 It has the id of the collected trace state variables.
1576 * On S/390 targets that provide the transactional-execution feature,
1577 the program interruption transaction diagnostic block (TDB) is now
1578 represented as a number of additional "registers" in GDB.
1580 * New remote packets
1584 The vCont packet supports a new 'r' action, that tells the remote
1585 stub to step through an address range itself, without GDB
1586 involvemement at each single-step.
1588 qXfer:libraries-svr4:read's annex
1589 The previously unused annex of the qXfer:libraries-svr4:read packet
1590 is now used to support passing an argument list. The remote stub
1591 reports support for this argument list to GDB's qSupported query.
1592 The defined arguments are "start" and "prev", used to reduce work
1593 necessary for library list updating, resulting in significant
1596 * New features in the GDB remote stub, GDBserver
1598 ** GDBserver now supports target-assisted range stepping. Currently
1599 enabled on x86/x86_64 GNU/Linux targets.
1601 ** GDBserver now adds element 'tvar' in the XML in the reply to
1602 'qXfer:traceframe-info:read'. It has the id of the collected
1603 trace state variables.
1605 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1608 * New 'z' formatter for printing and examining memory, this displays the
1609 value as hexadecimal zero padded on the left to the size of the type.
1611 * GDB can now use Windows x64 unwinding data.
1613 * The "set remotebaud" command has been replaced by "set serial baud".
1614 Similarly, "show remotebaud" has been replaced by "show serial baud".
1615 The "set remotebaud" and "show remotebaud" commands are still available
1616 to provide backward compatibility with older versions of GDB.
1618 *** Changes in GDB 7.6
1620 * Target record has been renamed to record-full.
1621 Record/replay is now enabled with the "record full" command.
1622 This also affects settings that are associated with full record/replay
1623 that have been moved from "set/show record" to "set/show record full":
1625 set|show record full insn-number-max
1626 set|show record full stop-at-limit
1627 set|show record full memory-query
1629 * A new record target "record-btrace" has been added. The new target
1630 uses hardware support to record the control-flow of a process. It
1631 does not support replaying the execution, but it implements the
1632 below new commands for investigating the recorded execution log.
1633 This new recording method can be enabled using:
1637 The "record-btrace" target is only available on Intel Atom processors
1638 and requires a Linux kernel 2.6.32 or later.
1640 * Two new commands have been added for record/replay to give information
1641 about the recorded execution without having to replay the execution.
1642 The commands are only supported by "record btrace".
1644 record instruction-history prints the execution history at
1645 instruction granularity
1647 record function-call-history prints the execution history at
1648 function granularity
1650 * New native configurations
1652 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1653 FreeBSD/powerpc powerpc*-*-freebsd
1654 x86_64/Cygwin x86_64-*-cygwin*
1655 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1659 ARM AArch64 aarch64*-*-elf
1660 ARM AArch64 GNU/Linux aarch64*-*-linux
1661 Lynx 178 PowerPC powerpc-*-lynx*178
1662 x86_64/Cygwin x86_64-*-cygwin*
1663 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1665 * If the configured location of system.gdbinit file (as given by the
1666 --with-system-gdbinit option at configure time) is in the
1667 data-directory (as specified by --with-gdb-datadir at configure
1668 time) or in one of its subdirectories, then GDB will look for the
1669 system-wide init file in the directory specified by the
1670 --data-directory command-line option.
1672 * New command line options:
1674 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1675 other initialization files, unlike -nx which disables all of them.
1677 * Removed command line options
1679 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1682 * The 'ptype' and 'whatis' commands now accept an argument to control
1685 * 'info proc' now works on some core files.
1689 ** Vectors can be created with gdb.Type.vector.
1691 ** Python's atexit.register now works in GDB.
1693 ** Types can be pretty-printed via a Python API.
1695 ** Python 3 is now supported (in addition to Python 2.4 or later)
1697 ** New class gdb.Architecture exposes GDB's internal representation
1698 of architecture in the Python API.
1700 ** New method Frame.architecture returns the gdb.Architecture object
1701 corresponding to the frame's architecture.
1703 * New Python-based convenience functions:
1705 ** $_memeq(buf1, buf2, length)
1706 ** $_streq(str1, str2)
1708 ** $_regex(str, regex)
1710 * The 'cd' command now defaults to using '~' (the home directory) if not
1713 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1714 default for GCC since November 2000.
1716 * The command 'forward-search' can now be abbreviated as 'fo'.
1718 * The command 'info tracepoints' can now display 'installed on target'
1719 or 'not installed on target' for each non-pending location of tracepoint.
1721 * New configure options
1723 --enable-libmcheck/--disable-libmcheck
1724 By default, development versions are built with -lmcheck on hosts
1725 that support it, in order to help track memory corruption issues.
1726 Release versions, on the other hand, are built without -lmcheck
1727 by default. The --enable-libmcheck/--disable-libmcheck configure
1728 options allow the user to override that default.
1729 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1730 This configure option allows the user to build GDB with
1731 libbabeltrace using which GDB can read Common Trace Format data.
1733 * New commands (for set/show, see "New options" below)
1736 Catch signals. This is similar to "handle", but allows commands and
1737 conditions to be attached.
1740 List the BFDs known to GDB.
1742 python-interactive [command]
1744 Start a Python interactive prompt, or evaluate the optional command
1745 and print the result of expressions.
1748 "py" is a new alias for "python".
1750 enable type-printer [name]...
1751 disable type-printer [name]...
1752 Enable or disable type printers.
1756 ** For the Renesas Super-H architecture, the "regs" command has been removed
1757 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1762 set print type methods (on|off)
1763 show print type methods
1764 Control whether method declarations are displayed by "ptype".
1765 The default is to show them.
1767 set print type typedefs (on|off)
1768 show print type typedefs
1769 Control whether typedef definitions are displayed by "ptype".
1770 The default is to show them.
1772 set filename-display basename|relative|absolute
1773 show filename-display
1774 Control the way in which filenames is displayed.
1775 The default is "relative", which preserves previous behavior.
1777 set trace-buffer-size
1778 show trace-buffer-size
1779 Request target to change the size of trace buffer.
1781 set remote trace-buffer-size-packet auto|on|off
1782 show remote trace-buffer-size-packet
1783 Control the use of the remote protocol `QTBuffer:size' packet.
1787 Control display of debugging messages related to ARM AArch64.
1790 set debug coff-pe-read
1791 show debug coff-pe-read
1792 Control display of debugging messages related to reading of COFF/PE
1797 Control display of debugging messages related to Mach-O symbols
1800 set debug notification
1801 show debug notification
1802 Control display of debugging info for async remote notification.
1806 ** Command parameter changes are now notified using new async record
1807 "=cmd-param-changed".
1808 ** Trace frame changes caused by command "tfind" are now notified using
1809 new async record "=traceframe-changed".
1810 ** The creation, deletion and modification of trace state variables
1811 are now notified using new async records "=tsv-created",
1812 "=tsv-deleted" and "=tsv-modified".
1813 ** The start and stop of process record are now notified using new
1814 async record "=record-started" and "=record-stopped".
1815 ** Memory changes are now notified using new async record
1817 ** The data-disassemble command response will include a "fullname" field
1818 containing the absolute file name when source has been requested.
1819 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1820 command, to allow pattern filling of memory areas.
1821 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1822 library load/unload events.
1823 ** The response to breakpoint commands and breakpoint async records
1824 includes an "installed" field containing a boolean state about each
1825 non-pending tracepoint location is whether installed on target or not.
1826 ** Output of the "-trace-status" command includes a "trace-file" field
1827 containing the name of the trace file being examined. This field is
1828 optional, and only present when examining a trace file.
1829 ** The "fullname" field is now always present along with the "file" field,
1830 even if the file cannot be found by GDB.
1832 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1833 You must have the LZMA library available when configuring GDB for this
1834 feature to be enabled. For more information, see:
1835 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1837 * New remote packets
1840 Set the size of trace buffer. The remote stub reports support for this
1841 packet to gdb's qSupported query.
1844 Enable Branch Trace Store (BTS)-based branch tracing for the current
1845 thread. The remote stub reports support for this packet to gdb's
1849 Disable branch tracing for the current thread. The remote stub reports
1850 support for this packet to gdb's qSupported query.
1853 Read the traced branches for the current thread. The remote stub
1854 reports support for this packet to gdb's qSupported query.
1856 *** Changes in GDB 7.5
1858 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1859 for more x32 ABI info.
1861 * GDB now supports access to MIPS DSP registers on Linux targets.
1863 * GDB now supports debugging microMIPS binaries.
1865 * The "info os" command on GNU/Linux can now display information on
1866 several new classes of objects managed by the operating system:
1867 "info os procgroups" lists process groups
1868 "info os files" lists file descriptors
1869 "info os sockets" lists internet-domain sockets
1870 "info os shm" lists shared-memory regions
1871 "info os semaphores" lists semaphores
1872 "info os msg" lists message queues
1873 "info os modules" lists loaded kernel modules
1875 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1876 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1877 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1878 options and inspect the probe arguments using the new $_probe_arg family
1879 of convenience variables. You can obtain more information about SystemTap
1880 in <http://sourceware.org/systemtap/>.
1882 * GDB now supports reversible debugging on ARM, it allows you to
1883 debug basic ARM and THUMB instructions, and provides
1884 record/replay support.
1886 * The option "symbol-reloading" has been deleted as it is no longer used.
1890 ** GDB commands implemented in Python can now be put in command class
1893 ** The "maint set python print-stack on|off" is now deleted.
1895 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1896 apply "flag enum"-style pretty-printing to any enum.
1898 ** gdb.lookup_symbol can now work when there is no current frame.
1900 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1901 the source at which the symbol was defined.
1903 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1904 method 'value'. The former indicates whether the symbol needs a
1905 frame in order to compute its value, and the latter computes the
1908 ** A new method 'referenced_value' on gdb.Value objects which can
1909 dereference pointer as well as C++ reference values.
1911 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1912 which return the global and static blocks (as gdb.Block objects),
1913 of the underlying symbol table, respectively.
1915 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1916 object associated with a PC value.
1918 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1919 of the address range occupied by code for the current source line.
1921 * Go language support.
1922 GDB now supports debugging programs written in the Go programming
1925 * GDBserver now supports stdio connections.
1926 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1928 * The binary "gdbtui" can no longer be built or installed.
1929 Use "gdb -tui" instead.
1931 * GDB will now print "flag" enums specially. A flag enum is one where
1932 all the enumerator values have no bits in common when pairwise
1933 "and"ed. When printing a value whose type is a flag enum, GDB will
1934 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1935 (gdb) print (enum E) 3
1938 * The filename part of a linespec will now match trailing components
1939 of a source file name. For example, "break gcc/expr.c:1000" will
1940 now set a breakpoint in build/gcc/expr.c, but not
1941 build/libcpp/expr.c.
1943 * The "info proc" and "generate-core-file" commands will now also
1944 work on remote targets connected to GDBserver on Linux.
1946 * The command "info catch" has been removed. It has been disabled
1947 since December 2007.
1949 * The "catch exception" and "catch assert" commands now accept
1950 a condition at the end of the command, much like the "break"
1951 command does. For instance:
1953 (gdb) catch exception Constraint_Error if Barrier = True
1955 Previously, it was possible to add a condition to such catchpoints,
1956 but it had to be done as a second step, after the catchpoint had been
1957 created, using the "condition" command.
1959 * The "info static-tracepoint-marker" command will now also work on
1960 native Linux targets with in-process agent.
1962 * GDB can now set breakpoints on inlined functions.
1964 * The .gdb_index section has been updated to include symbols for
1965 inlined functions. GDB will ignore older .gdb_index sections by
1966 default, which could cause symbol files to be loaded more slowly
1967 until their .gdb_index sections can be recreated. The new command
1968 "set use-deprecated-index-sections on" will cause GDB to use any older
1969 .gdb_index sections it finds. This will restore performance, but the
1970 ability to set breakpoints on inlined functions will be lost in symbol
1971 files with older .gdb_index sections.
1973 The .gdb_index section has also been updated to record more information
1974 about each symbol. This speeds up the "info variables", "info functions"
1975 and "info types" commands when used with programs having the .gdb_index
1976 section, as well as speeding up debugging with shared libraries using
1977 the .gdb_index section.
1979 * Ada support for GDB/MI Variable Objects has been added.
1981 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1986 ** New command -info-os is the MI equivalent of "info os".
1988 ** Output logs ("set logging" and related) now include MI output.
1992 ** "set use-deprecated-index-sections on|off"
1993 "show use-deprecated-index-sections on|off"
1994 Controls the use of deprecated .gdb_index sections.
1996 ** "catch load" and "catch unload" can be used to stop when a shared
1997 library is loaded or unloaded, respectively.
1999 ** "enable count" can be used to auto-disable a breakpoint after
2002 ** "info vtbl" can be used to show the virtual method tables for
2003 C++ and Java objects.
2005 ** "explore" and its sub commands "explore value" and "explore type"
2006 can be used to recursively explore values and types of
2007 expressions. These commands are available only if GDB is
2008 configured with '--with-python'.
2010 ** "info auto-load" shows status of all kinds of auto-loaded files,
2011 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2012 sequences of commands files, "info auto-load python-scripts"
2013 shows status of auto-loading Python script files,
2014 "info auto-load local-gdbinit" shows status of loading init file
2015 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2016 status of inferior specific thread debugging shared library loading.
2018 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2019 and "show auto-load-scripts" commands have been deprecated, use their
2020 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2021 and "show auto-load python-scripts" counterparts instead.
2023 ** "dprintf location,format,args..." creates a dynamic printf, which
2024 is basically a breakpoint that does a printf and immediately
2025 resumes your program's execution, so it is like a printf that you
2026 can insert dynamically at runtime instead of at compiletime.
2028 ** "set print symbol"
2030 Controls whether GDB attempts to display the symbol, if any,
2031 corresponding to addresses it prints. This defaults to "on", but
2032 you can set it to "off" to restore GDB's previous behavior.
2034 * Deprecated commands
2036 ** For the Renesas Super-H architecture, the "regs" command has been
2037 deprecated, and "info all-registers" should be used instead.
2041 Renesas RL78 rl78-*-elf
2042 HP OpenVMS ia64 ia64-hp-openvms*
2044 * GDBserver supports evaluation of breakpoint conditions. When
2045 support is advertised by GDBserver, GDB may be told to send the
2046 breakpoint conditions in bytecode form to GDBserver. GDBserver
2047 will only report the breakpoint trigger to GDB when its condition
2052 set mips compression
2053 show mips compression
2054 Select the compressed ISA encoding used in functions that have no symbol
2055 information available. The encoding can be set to either of:
2058 and is updated automatically from ELF file flags if available.
2060 set breakpoint condition-evaluation
2061 show breakpoint condition-evaluation
2062 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2063 GDBserver ("target"). Default option "auto" chooses the most efficient
2065 This option can improve debugger efficiency depending on the speed of the
2069 Disable auto-loading globally.
2072 Show auto-loading setting of all kinds of auto-loaded files.
2074 set auto-load gdb-scripts on|off
2075 show auto-load gdb-scripts
2076 Control auto-loading of GDB canned sequences of commands files.
2078 set auto-load python-scripts on|off
2079 show auto-load python-scripts
2080 Control auto-loading of Python script files.
2082 set auto-load local-gdbinit on|off
2083 show auto-load local-gdbinit
2084 Control loading of init file (.gdbinit) from current directory.
2086 set auto-load libthread-db on|off
2087 show auto-load libthread-db
2088 Control auto-loading of inferior specific thread debugging shared library.
2090 set auto-load scripts-directory <dir1>[:<dir2>...]
2091 show auto-load scripts-directory
2092 Set a list of directories from which to load auto-loaded scripts.
2093 Automatically loaded Python scripts and GDB scripts are located in one
2094 of the directories listed by this option.
2095 The delimiter (':' above) may differ according to the host platform.
2097 set auto-load safe-path <dir1>[:<dir2>...]
2098 show auto-load safe-path
2099 Set a list of directories from which it is safe to auto-load files.
2100 The delimiter (':' above) may differ according to the host platform.
2102 set debug auto-load on|off
2103 show debug auto-load
2104 Control display of debugging info for auto-loading the files above.
2106 set dprintf-style gdb|call|agent
2108 Control the way in which a dynamic printf is performed; "gdb"
2109 requests a GDB printf command, while "call" causes dprintf to call a
2110 function in the inferior. "agent" requests that the target agent
2111 (such as GDBserver) do the printing.
2113 set dprintf-function <expr>
2114 show dprintf-function
2115 set dprintf-channel <expr>
2116 show dprintf-channel
2117 Set the function and optional first argument to the call when using
2118 the "call" style of dynamic printf.
2120 set disconnected-dprintf on|off
2121 show disconnected-dprintf
2122 Control whether agent-style dynamic printfs continue to be in effect
2123 after GDB disconnects.
2125 * New configure options
2127 --with-auto-load-dir
2128 Configure default value for the 'set auto-load scripts-directory'
2129 setting above. It defaults to '$debugdir:$datadir/auto-load',
2130 $debugdir representing global debugging info directories (available
2131 via 'show debug-file-directory') and $datadir representing GDB's data
2132 directory (available via 'show data-directory').
2134 --with-auto-load-safe-path
2135 Configure default value for the 'set auto-load safe-path' setting
2136 above. It defaults to the --with-auto-load-dir setting.
2138 --without-auto-load-safe-path
2139 Set 'set auto-load safe-path' to '/', effectively disabling this
2142 * New remote packets
2144 z0/z1 conditional breakpoints extension
2146 The z0/z1 breakpoint insertion packets have been extended to carry
2147 a list of conditional expressions over to the remote stub depending on the
2148 condition evaluation mode. The use of this extension can be controlled
2149 via the "set remote conditional-breakpoints-packet" command.
2153 Specify the signals which the remote stub may pass to the debugged
2154 program without GDB involvement.
2156 * New command line options
2158 --init-command=FILE, -ix Like --command, -x but execute it
2159 before loading inferior.
2160 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2161 execute it before loading inferior.
2163 *** Changes in GDB 7.4
2165 * GDB now handles ambiguous linespecs more consistently; the existing
2166 FILE:LINE support has been expanded to other types of linespecs. A
2167 breakpoint will now be set on all matching locations in all
2168 inferiors, and locations will be added or removed according to
2171 * GDB now allows you to skip uninteresting functions and files when
2172 stepping with the "skip function" and "skip file" commands.
2174 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2175 and "show remote hardware-watchpoint-length-limit". These allows to
2176 set or show the maximum length limit (in bytes) of a remote
2177 target hardware watchpoint.
2179 This allows e.g. to use "unlimited" hardware watchpoints with the
2180 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2181 watchpoints are slower than real hardware watchpoints but are
2182 significantly faster than gdb software watchpoints.
2186 ** The register_pretty_printer function in module gdb.printing now takes
2187 an optional `replace' argument. If True, the new printer replaces any
2190 ** The "maint set python print-stack on|off" command has been
2191 deprecated and will be deleted in GDB 7.5.
2192 A new command: "set python print-stack none|full|message" has
2193 replaced it. Additionally, the default for "print-stack" is
2194 now "message", which just prints the error message without
2197 ** A prompt substitution hook (prompt_hook) is now available to the
2200 ** A new Python module, gdb.prompt has been added to the GDB Python
2201 modules library. This module provides functionality for
2202 escape sequences in prompts (used by set/show
2203 extended-prompt). These escape sequences are replaced by their
2204 corresponding value.
2206 ** Python commands and convenience-functions located in
2207 'data-directory'/python/gdb/command and
2208 'data-directory'/python/gdb/function are now automatically loaded
2211 ** Blocks now provide four new attributes. global_block and
2212 static_block will return the global and static blocks
2213 respectively. is_static and is_global are boolean attributes
2214 that indicate if the block is one of those two types.
2216 ** Symbols now provide the "type" attribute, the type of the symbol.
2218 ** The "gdb.breakpoint" function has been deprecated in favor of
2221 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2222 of a function. This class is based on the "finish" command
2223 available in the CLI.
2225 ** Type objects for struct and union types now allow access to
2226 the fields using standard Python dictionary (mapping) methods.
2227 For example, "some_type['myfield']" now works, as does
2228 "some_type.items()".
2230 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2233 ** A new function, "deep_items" has been added to the gdb.types
2234 module in the GDB Python modules library. This function returns
2235 an iterator over the fields of a struct or union type. Unlike
2236 the standard Python "iteritems" method, it will recursively traverse
2237 any anonymous fields.
2241 ** "*stopped" events can report several new "reason"s, such as
2244 ** Breakpoint changes are now notified using new async records, like
2245 "=breakpoint-modified".
2247 ** New command -ada-task-info.
2249 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2250 $sdir specifies the default system locations of shared libraries.
2251 $pdir specifies the directory where the libpthread used by the application
2254 GDB no longer looks in $sdir and $pdir after it has searched the directories
2255 mentioned in libthread-db-search-path. If you want to search those
2256 directories, they must be specified in libthread-db-search-path.
2257 The default value of libthread-db-search-path on GNU/Linux and Solaris
2258 systems is now "$sdir:$pdir".
2260 $pdir is not supported by gdbserver, it is currently ignored.
2261 $sdir is supported by gdbserver.
2263 * New configure option --with-iconv-bin.
2264 When using the internationalization support like the one in the GNU C
2265 library, GDB will invoke the "iconv" program to get a list of supported
2266 character sets. If this program lives in a non-standard location, one can
2267 use this option to specify where to find it.
2269 * When natively debugging programs on PowerPC BookE processors running
2270 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2271 watchpoints, which specify a mask in addition to an address to watch.
2272 The mask specifies that some bits of an address (the bits which are
2273 reset in the mask) should be ignored when matching the address accessed
2274 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2275 section in the user manual for more details.
2277 * The new option --once causes GDBserver to stop listening for connections once
2278 the first connection is made. The listening port used by GDBserver will
2279 become available after that.
2281 * New commands "info macros" and "alias" have been added.
2283 * New function parameters suffix @entry specifies value of function parameter
2284 at the time the function got called. Entry values are available only since
2290 "!" is now an alias of the "shell" command.
2291 Note that no space is needed between "!" and SHELL COMMAND.
2295 watch EXPRESSION mask MASK_VALUE
2296 The watch command now supports the mask argument which allows creation
2297 of masked watchpoints, if the current architecture supports this feature.
2299 info auto-load-scripts [REGEXP]
2300 This command was formerly named "maintenance print section-scripts".
2301 It is now generally useful and is no longer a maintenance-only command.
2303 info macro [-all] [--] MACRO
2304 The info macro command has new options `-all' and `--'. The first for
2305 printing all definitions of a macro. The second for explicitly specifying
2306 the end of arguments and the beginning of the macro name in case the macro
2307 name starts with a hyphen.
2309 collect[/s] EXPRESSIONS
2310 The tracepoint collect command now takes an optional modifier "/s"
2311 that directs it to dereference pointer-to-character types and
2312 collect the bytes of memory up to a zero byte. The behavior is
2313 similar to what you see when you use the regular print command on a
2314 string. An optional integer following the "/s" sets a bound on the
2315 number of bytes that will be collected.
2318 The trace start command now interprets any supplied arguments as a
2319 note to be recorded with the trace run, with an effect similar to
2320 setting the variable trace-notes.
2323 The trace stop command now interprets any arguments as a note to be
2324 mentioned along with the tstatus report that the trace was stopped
2325 with a command. The effect is similar to setting the variable
2328 * Tracepoints can now be enabled and disabled at any time after a trace
2329 experiment has been started using the standard "enable" and "disable"
2330 commands. It is now possible to start a trace experiment with no enabled
2331 tracepoints; GDB will display a warning, but will allow the experiment to
2332 begin, assuming that tracepoints will be enabled as needed while the trace
2335 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2336 locations with 4-byte instructions, when they were previously
2337 limited to locations with instructions of 5 bytes or longer.
2341 set debug dwarf2-read
2342 show debug dwarf2-read
2343 Turns on or off display of debugging messages related to reading
2344 DWARF debug info. The default is off.
2346 set debug symtab-create
2347 show debug symtab-create
2348 Turns on or off display of debugging messages related to symbol table
2349 creation. The default is off.
2352 show extended-prompt
2353 Set the GDB prompt, and allow escape sequences to be inserted to
2354 display miscellaneous information (see 'help set extended-prompt'
2355 for the list of sequences). This prompt (and any information
2356 accessed through the escape sequences) is updated every time the
2357 prompt is displayed.
2359 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2360 show print entry-values
2361 Set printing of frame argument values at function entry. In some cases
2362 GDB can determine the value of function argument which was passed by the
2363 function caller, even if the value was modified inside the called function.
2365 set debug entry-values
2366 show debug entry-values
2367 Control display of debugging info for determining frame argument values at
2368 function entry and virtual tail call frames.
2370 set basenames-may-differ
2371 show basenames-may-differ
2372 Set whether a source file may have multiple base names.
2373 (A "base name" is the name of a file with the directory part removed.
2374 Example: The base name of "/home/user/hello.c" is "hello.c".)
2375 If set, GDB will canonicalize file names (e.g., expand symlinks)
2376 before comparing them. Canonicalization is an expensive operation,
2377 but it allows the same file be known by more than one base name.
2378 If not set (the default), all source files are assumed to have just
2379 one base name, and gdb will do file name comparisons more efficiently.
2385 Set a user name and notes for the current and any future trace runs.
2386 This is useful for long-running and/or disconnected traces, to
2387 inform others (or yourself) as to who is running the trace, supply
2388 contact information, or otherwise explain what is going on.
2390 set trace-stop-notes
2391 show trace-stop-notes
2392 Set a note attached to the trace run, that is displayed when the
2393 trace has been stopped by a tstop command. This is useful for
2394 instance as an explanation, if you are stopping a trace run that was
2395 started by someone else.
2397 * New remote packets
2401 Dynamically enable a tracepoint in a started trace experiment.
2405 Dynamically disable a tracepoint in a started trace experiment.
2409 Set the user and notes of the trace run.
2413 Query the current status of a tracepoint.
2417 Query the minimum length of instruction at which a fast tracepoint may
2420 * Dcache size (number of lines) and line-size are now runtime-configurable
2421 via "set dcache line" and "set dcache line-size" commands.
2425 Texas Instruments TMS320C6x tic6x-*-*
2429 Renesas RL78 rl78-*-elf
2431 *** Changes in GDB 7.3.1
2433 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2435 *** Changes in GDB 7.3
2437 * GDB has a new command: "thread find [REGEXP]".
2438 It finds the thread id whose name, target id, or thread extra info
2439 matches the given regular expression.
2441 * The "catch syscall" command now works on mips*-linux* targets.
2443 * The -data-disassemble MI command now supports modes 2 and 3 for
2444 dumping the instruction opcodes.
2446 * New command line options
2448 -data-directory DIR Specify DIR as the "data-directory".
2449 This is mostly for testing purposes.
2451 * The "maint set python auto-load on|off" command has been renamed to
2452 "set auto-load-scripts on|off".
2454 * GDB has a new command: "set directories".
2455 It is like the "dir" command except that it replaces the
2456 source path list instead of augmenting it.
2458 * GDB now understands thread names.
2460 On GNU/Linux, "info threads" will display the thread name as set by
2461 prctl or pthread_setname_np.
2463 There is also a new command, "thread name", which can be used to
2464 assign a name internally for GDB to display.
2467 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2468 has been integrated into GDB.
2472 ** The function gdb.Write now accepts an optional keyword 'stream'.
2473 This keyword, when provided, will direct the output to either
2474 stdout, stderr, or GDB's logging output.
2476 ** Parameters can now be be sub-classed in Python, and in particular
2477 you may implement the get_set_doc and get_show_doc functions.
2478 This improves how Parameter set/show documentation is processed
2479 and allows for more dynamic content.
2481 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2482 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2483 have an is_valid method.
2485 ** Breakpoints can now be sub-classed in Python, and in particular
2486 you may implement a 'stop' function that is executed each time
2487 the inferior reaches that breakpoint.
2489 ** New function gdb.lookup_global_symbol looks up a global symbol.
2491 ** GDB values in Python are now callable if the value represents a
2492 function. For example, if 'some_value' represents a function that
2493 takes two integer parameters and returns a value, you can call
2494 that function like so:
2496 result = some_value (10,20)
2498 ** Module gdb.types has been added.
2499 It contains a collection of utilities for working with gdb.Types objects:
2500 get_basic_type, has_field, make_enum_dict.
2502 ** Module gdb.printing has been added.
2503 It contains utilities for writing and registering pretty-printers.
2504 New classes: PrettyPrinter, SubPrettyPrinter,
2505 RegexpCollectionPrettyPrinter.
2506 New function: register_pretty_printer.
2508 ** New commands "info pretty-printers", "enable pretty-printer" and
2509 "disable pretty-printer" have been added.
2511 ** gdb.parameter("directories") is now available.
2513 ** New function gdb.newest_frame returns the newest frame in the
2516 ** The gdb.InferiorThread class has a new "name" attribute. This
2517 holds the thread's name.
2519 ** Python Support for Inferior events.
2520 Python scripts can add observers to be notified of events
2521 occurring in the process being debugged.
2522 The following events are currently supported:
2523 - gdb.events.cont Continue event.
2524 - gdb.events.exited Inferior exited event.
2525 - gdb.events.stop Signal received, and Breakpoint hit events.
2529 ** GDB now puts template parameters in scope when debugging in an
2530 instantiation. For example, if you have:
2532 template<int X> int func (void) { return X; }
2534 then if you step into func<5>, "print X" will show "5". This
2535 feature requires proper debuginfo support from the compiler; it
2536 was added to GCC 4.5.
2538 ** The motion commands "next", "finish", "until", and "advance" now
2539 work better when exceptions are thrown. In particular, GDB will
2540 no longer lose control of the inferior; instead, the GDB will
2541 stop the inferior at the point at which the exception is caught.
2542 This functionality requires a change in the exception handling
2543 code that was introduced in GCC 4.5.
2545 * GDB now follows GCC's rules on accessing volatile objects when
2546 reading or writing target state during expression evaluation.
2547 One notable difference to prior behavior is that "print x = 0"
2548 no longer generates a read of x; the value of the assignment is
2549 now always taken directly from the value being assigned.
2551 * GDB now has some support for using labels in the program's source in
2552 linespecs. For instance, you can use "advance label" to continue
2553 execution to a label.
2555 * GDB now has support for reading and writing a new .gdb_index
2556 section. This section holds a fast index of DWARF debugging
2557 information and can be used to greatly speed up GDB startup and
2558 operation. See the documentation for `save gdb-index' for details.
2560 * The "watch" command now accepts an optional "-location" argument.
2561 When used, this causes GDB to watch the memory referred to by the
2562 expression. Such a watchpoint is never deleted due to it going out
2565 * GDB now supports thread debugging of core dumps on GNU/Linux.
2567 GDB now activates thread debugging using the libthread_db library
2568 when debugging GNU/Linux core dumps, similarly to when debugging
2569 live processes. As a result, when debugging a core dump file, GDB
2570 is now able to display pthread_t ids of threads. For example, "info
2571 threads" shows the same output as when debugging the process when it
2572 was live. In earlier releases, you'd see something like this:
2575 * 1 LWP 6780 main () at main.c:10
2577 While now you see this:
2580 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2582 It is also now possible to inspect TLS variables when debugging core
2585 When debugging a core dump generated on a machine other than the one
2586 used to run GDB, you may need to point GDB at the correct
2587 libthread_db library with the "set libthread-db-search-path"
2588 command. See the user manual for more details on this command.
2590 * When natively debugging programs on PowerPC BookE processors running
2591 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2592 which stop execution of the inferior whenever it executes an instruction
2593 at any address within the specified range. See the "PowerPC Embedded"
2594 section in the user manual for more details.
2596 * New features in the GDB remote stub, GDBserver
2598 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2599 and i686 LynxOS (version 5.x).
2601 ** GDBserver is now supported on Blackfin Linux.
2603 * New native configurations
2605 ia64 HP-UX ia64-*-hpux*
2609 Analog Devices, Inc. Blackfin Processor bfin-*
2611 * Ada task switching is now supported on sparc-elf targets when
2612 debugging a program using the Ravenscar Profile. For more information,
2613 see the "Tasking Support when using the Ravenscar Profile" section
2614 in the GDB user manual.
2616 * Guile support was removed.
2618 * New features in the GNU simulator
2620 ** The --map-info flag lists all known core mappings.
2622 ** CFI flashes may be simulated via the "cfi" device.
2624 *** Changes in GDB 7.2
2626 * Shared library support for remote targets by default
2628 When GDB is configured for a generic, non-OS specific target, like
2629 for example, --target=arm-eabi or one of the many *-*-elf targets,
2630 GDB now queries remote stubs for loaded shared libraries using the
2631 `qXfer:libraries:read' packet. Previously, shared library support
2632 was always disabled for such configurations.
2636 ** Argument Dependent Lookup (ADL)
2638 In C++ ADL lookup directs function search to the namespaces of its
2639 arguments even if the namespace has not been imported.
2649 Here the compiler will search for `foo' in the namespace of 'b'
2650 and find A::foo. GDB now supports this. This construct is commonly
2651 used in the Standard Template Library for operators.
2653 ** Improved User Defined Operator Support
2655 In addition to member operators, GDB now supports lookup of operators
2656 defined in a namespace and imported with a `using' directive, operators
2657 defined in the global scope, operators imported implicitly from an
2658 anonymous namespace, and the ADL operators mentioned in the previous
2660 GDB now also supports proper overload resolution for all the previously
2661 mentioned flavors of operators.
2663 ** static const class members
2665 Printing of static const class members that are initialized in the
2666 class definition has been fixed.
2668 * Windows Thread Information Block access.
2670 On Windows targets, GDB now supports displaying the Windows Thread
2671 Information Block (TIB) structure. This structure is visible either
2672 by using the new command `info w32 thread-information-block' or, by
2673 dereferencing the new convenience variable named `$_tlb', a
2674 thread-specific pointer to the TIB. This feature is also supported
2675 when remote debugging using GDBserver.
2677 * Static tracepoints
2679 Static tracepoints are calls in the user program into a tracing
2680 library. One such library is a port of the LTTng kernel tracer to
2681 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2682 When debugging with GDBserver, GDB now supports combining the GDB
2683 tracepoint machinery with such libraries. For example: the user can
2684 use GDB to probe a static tracepoint marker (a call from the user
2685 program into the tracing library) with the new "strace" command (see
2686 "New commands" below). This creates a "static tracepoint" in the
2687 breakpoint list, that can be manipulated with the same feature set
2688 as fast and regular tracepoints. E.g., collect registers, local and
2689 global variables, collect trace state variables, and define
2690 tracepoint conditions. In addition, the user can collect extra
2691 static tracepoint marker specific data, by collecting the new
2692 $_sdata internal variable. When analyzing the trace buffer, you can
2693 inspect $_sdata like any other variable available to GDB. For more
2694 information, see the "Tracepoints" chapter in GDB user manual. New
2695 remote packets have been defined to support static tracepoints, see
2696 the "New remote packets" section below.
2698 * Better reconstruction of tracepoints after disconnected tracing
2700 GDB will attempt to download the original source form of tracepoint
2701 definitions when starting a trace run, and then will upload these
2702 upon reconnection to the target, resulting in a more accurate
2703 reconstruction of the tracepoints that are in use on the target.
2707 You can now exercise direct control over the ways that GDB can
2708 affect your program. For instance, you can disallow the setting of
2709 breakpoints, so that the program can run continuously (assuming
2710 non-stop mode). In addition, the "observer" variable is available
2711 to switch all of the different controls; in observer mode, GDB
2712 cannot affect the target's behavior at all, which is useful for
2713 tasks like diagnosing live systems in the field.
2715 * The new convenience variable $_thread holds the number of the
2718 * New remote packets
2722 Return the address of the Windows Thread Information Block of a given thread.
2726 In response to several of the tracepoint packets, the target may now
2727 also respond with a number of intermediate `qRelocInsn' request
2728 packets before the final result packet, to have GDB handle
2729 relocating an instruction to execute at a different address. This
2730 is particularly useful for stubs that support fast tracepoints. GDB
2731 reports support for this feature in the qSupported packet.
2735 List static tracepoint markers in the target program.
2739 List static tracepoint markers at a given address in the target
2742 qXfer:statictrace:read
2744 Read the static trace data collected (by a `collect $_sdata'
2745 tracepoint action). The remote stub reports support for this packet
2746 to gdb's qSupported query.
2750 Send the current settings of GDB's permission flags.
2754 Send part of the source (textual) form of a tracepoint definition,
2755 which includes location, conditional, and action list.
2757 * The source command now accepts a -s option to force searching for the
2758 script in the source search path even if the script name specifies
2761 * New features in the GDB remote stub, GDBserver
2763 - GDBserver now support tracepoints (including fast tracepoints, and
2764 static tracepoints). The feature is currently supported by the
2765 i386-linux and amd64-linux builds. See the "Tracepoints support
2766 in gdbserver" section in the manual for more information.
2768 GDBserver JIT compiles the tracepoint's conditional agent
2769 expression bytecode into native code whenever possible for low
2770 overhead dynamic tracepoints conditionals. For such tracepoints,
2771 an expression that examines program state is evaluated when the
2772 tracepoint is reached, in order to determine whether to capture
2773 trace data. If the condition is simple and false, processing the
2774 tracepoint finishes very quickly and no data is gathered.
2776 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2777 for static tracepoints support.
2779 - GDBserver now supports x86_64 Windows 64-bit debugging.
2781 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2782 it understands register description.
2784 * The --batch flag now disables pagination and queries.
2786 * X86 general purpose registers
2788 GDB now supports reading/writing byte, word and double-word x86
2789 general purpose registers directly. This means you can use, say,
2790 $ah or $ax to refer, respectively, to the byte register AH and
2791 16-bit word register AX that are actually portions of the 32-bit
2792 register EAX or 64-bit register RAX.
2794 * The `commands' command now accepts a range of breakpoints to modify.
2795 A plain `commands' following a command that creates multiple
2796 breakpoints affects all the breakpoints set by that command. This
2797 applies to breakpoints set by `rbreak', and also applies when a
2798 single `break' command creates multiple breakpoints (e.g.,
2799 breakpoints on overloaded c++ functions).
2801 * The `rbreak' command now accepts a filename specification as part of
2802 its argument, limiting the functions selected by the regex to those
2803 in the specified file.
2805 * Support for remote debugging Windows and SymbianOS shared libraries
2806 from Unix hosts has been improved. Non Windows GDB builds now can
2807 understand target reported file names that follow MS-DOS based file
2808 system semantics, such as file names that include drive letters and
2809 use the backslash character as directory separator. This makes it
2810 possible to transparently use the "set sysroot" and "set
2811 solib-search-path" on Unix hosts to point as host copies of the
2812 target's shared libraries. See the new command "set
2813 target-file-system-kind" described below, and the "Commands to
2814 specify files" section in the user manual for more information.
2818 eval template, expressions...
2819 Convert the values of one or more expressions under the control
2820 of the string template to a command line, and call it.
2822 set target-file-system-kind unix|dos-based|auto
2823 show target-file-system-kind
2824 Set or show the assumed file system kind for target reported file
2827 save breakpoints <filename>
2828 Save all current breakpoint definitions to a file suitable for use
2829 in a later debugging session. To read the saved breakpoint
2830 definitions, use the `source' command.
2832 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2835 info static-tracepoint-markers
2836 Display information about static tracepoint markers in the target.
2838 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2839 Define a static tracepoint by probing a marker at the given
2840 function, line, address, or marker ID.
2844 Enable and disable observer mode.
2846 set may-write-registers on|off
2847 set may-write-memory on|off
2848 set may-insert-breakpoints on|off
2849 set may-insert-tracepoints on|off
2850 set may-insert-fast-tracepoints on|off
2851 set may-interrupt on|off
2852 Set individual permissions for GDB effects on the target. Note that
2853 some of these settings can have undesirable or surprising
2854 consequences, particularly when changed in the middle of a session.
2855 For instance, disabling the writing of memory can prevent
2856 breakpoints from being inserted, cause single-stepping to fail, or
2857 even crash your program, if you disable after breakpoints have been
2858 inserted. However, GDB should not crash.
2860 set record memory-query on|off
2861 show record memory-query
2862 Control whether to stop the inferior if memory changes caused
2863 by an instruction cannot be recorded.
2868 The disassemble command now supports "start,+length" form of two arguments.
2872 ** GDB now provides a new directory location, called the python directory,
2873 where Python scripts written for GDB can be installed. The location
2874 of that directory is <data-directory>/python, where <data-directory>
2875 is the GDB data directory. For more details, see section `Scripting
2876 GDB using Python' in the manual.
2878 ** The GDB Python API now has access to breakpoints, symbols, symbol
2879 tables, program spaces, inferiors, threads and frame's code blocks.
2880 Additionally, GDB Parameters can now be created from the API, and
2881 manipulated via set/show in the CLI.
2883 ** New functions gdb.target_charset, gdb.target_wide_charset,
2884 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2886 ** New exception gdb.GdbError.
2888 ** Pretty-printers are now also looked up in the current program space.
2890 ** Pretty-printers can now be individually enabled and disabled.
2892 ** GDB now looks for names of Python scripts to auto-load in a
2893 special section named `.debug_gdb_scripts', in addition to looking
2894 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2896 * Tracepoint actions were unified with breakpoint commands. In particular,
2897 there are no longer differences in "info break" output for breakpoints and
2898 tracepoints and the "commands" command can be used for both tracepoints and
2899 regular breakpoints.
2903 ARM Symbian arm*-*-symbianelf*
2905 * D language support.
2906 GDB now supports debugging programs written in the D programming
2909 * GDB now supports the extended ptrace interface for PowerPC which is
2910 available since Linux kernel version 2.6.34. This automatically enables
2911 any hardware breakpoints and additional hardware watchpoints available in
2912 the processor. The old ptrace interface exposes just one hardware
2913 watchpoint and no hardware breakpoints.
2915 * GDB is now able to use the Data Value Compare (DVC) register available on
2916 embedded PowerPC processors to implement in hardware simple watchpoint
2917 conditions of the form:
2919 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2921 This works in native GDB running on Linux kernels with the extended ptrace
2922 interface mentioned above.
2924 *** Changes in GDB 7.1
2928 ** Namespace Support
2930 GDB now supports importing of namespaces in C++. This enables the
2931 user to inspect variables from imported namespaces. Support for
2932 namepace aliasing has also been added. So, if a namespace is
2933 aliased in the current scope (e.g. namepace C=A; ) the user can
2934 print variables using the alias (e.g. (gdb) print C::x).
2938 All known bugs relating to the printing of virtual base class were
2939 fixed. It is now possible to call overloaded static methods using a
2944 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2945 and reinterpret_cast<> are now handled by the C++ expression parser.
2949 Xilinx MicroBlaze microblaze-*-*
2954 Xilinx MicroBlaze microblaze
2957 * Multi-program debugging.
2959 GDB now has support for multi-program (a.k.a. multi-executable or
2960 multi-exec) debugging. This allows for debugging multiple inferiors
2961 simultaneously each running a different program under the same GDB
2962 session. See "Debugging Multiple Inferiors and Programs" in the
2963 manual for more information. This implied some user visible changes
2964 in the multi-inferior support. For example, "info inferiors" now
2965 lists inferiors that are not running yet or that have exited
2966 already. See also "New commands" and "New options" below.
2968 * New tracing features
2970 GDB's tracepoint facility now includes several new features:
2972 ** Trace state variables
2974 GDB tracepoints now include support for trace state variables, which
2975 are variables managed by the target agent during a tracing
2976 experiment. They are useful for tracepoints that trigger each
2977 other, so for instance one tracepoint can count hits in a variable,
2978 and then a second tracepoint has a condition that is true when the
2979 count reaches a particular value. Trace state variables share the
2980 $-syntax of GDB convenience variables, and can appear in both
2981 tracepoint actions and condition expressions. Use the "tvariable"
2982 command to create, and "info tvariables" to view; see "Trace State
2983 Variables" in the manual for more detail.
2987 GDB now includes an option for defining fast tracepoints, which
2988 targets may implement more efficiently, such as by installing a jump
2989 into the target agent rather than a trap instruction. The resulting
2990 speedup can be by two orders of magnitude or more, although the
2991 tradeoff is that some program locations on some target architectures
2992 might not allow fast tracepoint installation, for instance if the
2993 instruction to be replaced is shorter than the jump. To request a
2994 fast tracepoint, use the "ftrace" command, with syntax identical to
2995 the regular trace command.
2997 ** Disconnected tracing
2999 It is now possible to detach GDB from the target while it is running
3000 a trace experiment, then reconnect later to see how the experiment
3001 is going. In addition, a new variable disconnected-tracing lets you
3002 tell the target agent whether to continue running a trace if the
3003 connection is lost unexpectedly.
3007 GDB now has the ability to save the trace buffer into a file, and
3008 then use that file as a target, similarly to you can do with
3009 corefiles. You can select trace frames, print data that was
3010 collected in them, and use tstatus to display the state of the
3011 tracing run at the moment that it was saved. To create a trace
3012 file, use "tsave <filename>", and to use it, do "target tfile
3015 ** Circular trace buffer
3017 You can ask the target agent to handle the trace buffer as a
3018 circular buffer, discarding the oldest trace frames to make room for
3019 newer ones, by setting circular-trace-buffer to on. This feature may
3020 not be available for all target agents.
3025 The disassemble command, when invoked with two arguments, now requires
3026 the arguments to be comma-separated.
3029 The info variables command now displays variable definitions. Files
3030 which only declare a variable are not shown.
3033 The source command is now capable of sourcing Python scripts.
3034 This feature is dependent on the debugger being build with Python
3037 Related to this enhancement is also the introduction of a new command
3038 "set script-extension" (see below).
3040 * New commands (for set/show, see "New options" below)
3042 record save [<FILENAME>]
3043 Save a file (in core file format) containing the process record
3044 execution log for replay debugging at a later time.
3046 record restore <FILENAME>
3047 Restore the process record execution log that was saved at an
3048 earlier time, for replay debugging.
3050 add-inferior [-copies <N>] [-exec <FILENAME>]
3053 clone-inferior [-copies <N>] [ID]
3054 Make a new inferior ready to execute the same program another
3055 inferior has loaded.
3060 maint info program-spaces
3061 List the program spaces loaded into GDB.
3063 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3064 show remote interrupt-sequence
3065 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3066 as the sequence to the remote target in order to interrupt the execution.
3067 Ctrl-C is a default. Some system prefers BREAK which is high level of
3068 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3069 Magic SysRq g. It is BREAK signal and character 'g'.
3071 set remote interrupt-on-connect [on | off]
3072 show remote interrupt-on-connect
3073 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3074 remote target when gdb connects to it. This is needed when you debug
3077 set remotebreak [on | off]
3079 Deprecated. Use "set/show remote interrupt-sequence" instead.
3081 tvariable $NAME [ = EXP ]
3082 Create or modify a trace state variable.
3085 List trace state variables and their values.
3087 delete tvariable $NAME ...
3088 Delete one or more trace state variables.
3091 Evaluate the given expressions without collecting anything into the
3092 trace buffer. (Valid in tracepoint actions only.)
3094 ftrace FN / FILE:LINE / *ADDR
3095 Define a fast tracepoint at the given function, line, or address.
3097 * New expression syntax
3099 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3100 GDB now parses 0b101010 identically with 42.
3104 set follow-exec-mode new|same
3105 show follow-exec-mode
3106 Control whether GDB reuses the same inferior across an exec call or
3107 creates a new one. This is useful to be able to restart the old
3108 executable after the inferior having done an exec call.
3110 set default-collect EXPR, ...
3111 show default-collect
3112 Define a list of expressions to be collected at each tracepoint.
3113 This is a useful way to ensure essential items are not overlooked,
3114 such as registers or a critical global variable.
3116 set disconnected-tracing
3117 show disconnected-tracing
3118 If set to 1, the target is instructed to continue tracing if it
3119 loses its connection to GDB. If 0, the target is to stop tracing
3122 set circular-trace-buffer
3123 show circular-trace-buffer
3124 If set to on, the target is instructed to use a circular trace buffer
3125 and discard the oldest trace frames instead of stopping the trace due
3126 to a full trace buffer. If set to off, the trace stops when the buffer
3127 fills up. Some targets may not support this.
3129 set script-extension off|soft|strict
3130 show script-extension
3131 If set to "off", the debugger does not perform any script language
3132 recognition, and all sourced files are assumed to be GDB scripts.
3133 If set to "soft" (the default), files are sourced according to
3134 filename extension, falling back to GDB scripts if the first
3136 If set to "strict", files are sourced according to filename extension.
3138 set ada trust-PAD-over-XVS on|off
3139 show ada trust-PAD-over-XVS
3140 If off, activate a workaround against a bug in the debugging information
3141 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3142 the GCC sources for more information about the GNAT encoding and
3143 PAD types in particular). It is always safe to set this option to
3144 off, but this introduces a slight performance penalty. The default
3147 * Python API Improvements
3149 ** GDB provides the new class gdb.LazyString. This is useful in
3150 some pretty-printing cases. The new method gdb.Value.lazy_string
3151 provides a simple way to create objects of this type.
3153 ** The fields returned by gdb.Type.fields now have an
3154 `is_base_class' attribute.
3156 ** The new method gdb.Type.range returns the range of an array type.
3158 ** The new method gdb.parse_and_eval can be used to parse and
3159 evaluate an expression.
3161 * New remote packets
3164 Define a trace state variable.
3167 Get the current value of a trace state variable.
3170 Set desired tracing behavior upon disconnection.
3173 Set the trace buffer to be linear or circular.
3176 Get data about the tracepoints currently in use.
3180 Process record now works correctly with hardware watchpoints.
3182 Multiple bug fixes have been made to the mips-irix port, making it
3183 much more reliable. In particular:
3184 - Debugging threaded applications is now possible again. Previously,
3185 GDB would hang while starting the program, or while waiting for
3186 the program to stop at a breakpoint.
3187 - Attaching to a running process no longer hangs.
3188 - An error occurring while loading a core file has been fixed.
3189 - Changing the value of the PC register now works again. This fixes
3190 problems observed when using the "jump" command, or when calling
3191 a function from GDB, or even when assigning a new value to $pc.
3192 - With the "finish" and "return" commands, the return value for functions
3193 returning a small array is now correctly printed.
3194 - It is now possible to break on shared library code which gets executed
3195 during a shared library init phase (code executed while executing
3196 their .init section). Previously, the breakpoint would have no effect.
3197 - GDB is now able to backtrace through the signal handler for
3198 non-threaded programs.
3200 PIE (Position Independent Executable) programs debugging is now supported.
3201 This includes debugging execution of PIC (Position Independent Code) shared
3202 libraries although for that, it should be possible to run such libraries as an
3205 *** Changes in GDB 7.0
3207 * GDB now has an interface for JIT compilation. Applications that
3208 dynamically generate code can create symbol files in memory and register
3209 them with GDB. For users, the feature should work transparently, and
3210 for JIT developers, the interface is documented in the GDB manual in the
3211 "JIT Compilation Interface" chapter.
3213 * Tracepoints may now be conditional. The syntax is as for
3214 breakpoints; either an "if" clause appended to the "trace" command,
3215 or the "condition" command is available. GDB sends the condition to
3216 the target for evaluation using the same bytecode format as is used
3217 for tracepoint actions.
3219 * The disassemble command now supports: an optional /r modifier, print the
3220 raw instructions in hex as well as in symbolic form, and an optional /m
3221 modifier to print mixed source+assembly.
3223 * Process record and replay
3225 In a architecture environment that supports ``process record and
3226 replay'', ``process record and replay'' target can record a log of
3227 the process execution, and replay it with both forward and reverse
3230 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3231 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3232 set execution-direction {forward|reverse}, for targets that support
3235 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3236 feature is available with a native GDB running on kernel version
3239 * GDB now has support for multi-byte and wide character sets on the
3240 target. Strings whose character type is wchar_t, char16_t, or
3241 char32_t are now correctly printed. GDB supports wide- and unicode-
3242 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3243 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3244 `printf'. This feature requires iconv to work properly; if your
3245 system does not have a working iconv, GDB can use GNU libiconv. See
3246 the installation instructions for more information.
3248 * GDB now supports automatic retrieval of shared library files from
3249 remote targets. To use this feature, specify a system root that begins
3250 with the `remote:' prefix, either via the `set sysroot' command or via
3251 the `--with-sysroot' configure-time option.
3253 * "info sharedlibrary" now takes an optional regex of libraries to show,
3254 and it now reports if a shared library has no debugging information.
3256 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3257 now complete on file names.
3259 * When completing in expressions, gdb will attempt to limit
3260 completions to allowable structure or union fields, where appropriate.
3261 For instance, consider:
3263 # struct example { int f1; double f2; };
3264 # struct example variable;
3267 If the user types TAB at the end of this command line, the available
3268 completions will be "f1" and "f2".
3270 * Inlined functions are now supported. They show up in backtraces, and
3271 the "step", "next", and "finish" commands handle them automatically.
3273 * GDB now supports the token-splicing (##) and stringification (#)
3274 operators when expanding macros. It also supports variable-arity
3277 * GDB now supports inspecting extra signal information, exported by
3278 the new $_siginfo convenience variable. The feature is currently
3279 implemented on linux ARM, i386 and amd64.
3281 * GDB can now display the VFP floating point registers and NEON vector
3282 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3283 can provide these registers (requires Linux 2.6.30 or later). Remote
3284 and simulator targets may also provide them.
3286 * New remote packets
3289 Search memory for a sequence of bytes.
3292 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3293 operation over reliable transport links. Use of this packet is
3294 controlled by the `set remote noack-packet' command.
3297 Kill the process with the specified process ID. Use this in preference
3298 to `k' when multiprocess protocol extensions are supported.
3301 Obtains additional operating system information
3305 Read or write additional signal information.
3307 * Removed remote protocol undocumented extension
3309 An undocumented extension to the remote protocol's `S' stop reply
3310 packet that permited the stub to pass a process id was removed.
3311 Remote servers should use the `T' stop reply packet instead.
3313 * GDB now supports multiple function calling conventions according to the
3314 DWARF-2 DW_AT_calling_convention function attribute.
3316 * The SH target utilizes the aforementioned change to distinguish between gcc
3317 and Renesas calling convention. It also adds the new CLI commands
3318 `set/show sh calling-convention'.
3320 * GDB can now read compressed debug sections, as produced by GNU gold
3321 with the --compress-debug-sections=zlib flag.
3323 * 64-bit core files are now supported on AIX.
3325 * Thread switching is now supported on Tru64.
3327 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3328 which will be allocated using malloc later in program execution.
3330 * The qXfer:libraries:read remote procotol packet now allows passing a
3331 list of section offsets.
3333 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3334 conditions handling signals delivered during attach or thread creation
3335 have also been fixed.
3337 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3338 From the user's standpoint, all unqualified instances of True and False
3339 are treated as the standard definitions, regardless of context.
3341 * GDB now parses C++ symbol and type names more flexibly. For
3344 template<typename T> class C { };
3347 GDB will now correctly handle all of:
3349 ptype C<char const *>
3350 ptype C<char const*>
3351 ptype C<const char *>
3352 ptype C<const char*>
3354 * New features in the GDB remote stub, gdbserver
3356 - The "--wrapper" command-line argument tells gdbserver to use a
3357 wrapper program to launch programs for debugging.
3359 - On PowerPC and S/390 targets, it is now possible to use a single
3360 gdbserver executable to debug both 32-bit and 64-bit programs.
3361 (This requires gdbserver itself to be built as a 64-bit executable.)
3363 - gdbserver uses the new noack protocol mode for TCP connections to
3364 reduce communications latency, if also supported and enabled in GDB.
3366 - Support for the sparc64-linux-gnu target is now included in
3369 - The amd64-linux build of gdbserver now supports debugging both
3370 32-bit and 64-bit programs.
3372 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3373 now support hardware watchpoints, and will use them automatically
3378 GDB now has support for scripting using Python. Whether this is
3379 available is determined at configure time.
3381 New GDB commands can now be written in Python.
3383 * Ada tasking support
3385 Ada tasks can now be inspected in GDB. The following commands have
3389 Print the list of Ada tasks.
3391 Print detailed information about task number N.
3393 Print the task number of the current task.
3395 Switch the context of debugging to task number N.
3397 * Support for user-defined prefixed commands. The "define" command can
3398 add new commands to existing prefixes, e.g. "target".
3400 * Multi-inferior, multi-process debugging.
3402 GDB now has generalized support for multi-inferior debugging. See
3403 "Debugging Multiple Inferiors" in the manual for more information.
3404 Although availability still depends on target support, the command
3405 set is more uniform now. The GNU/Linux specific multi-forks support
3406 has been migrated to this new framework. This implied some user
3407 visible changes; see "New commands" and also "Removed commands"
3410 * Target descriptions can now describe the target OS ABI. See the
3411 "Target Description Format" section in the user manual for more
3414 * Target descriptions can now describe "compatible" architectures
3415 to indicate that the target can execute applications for a different
3416 architecture in addition to those for the main target architecture.
3417 See the "Target Description Format" section in the user manual for
3420 * Multi-architecture debugging.
3422 GDB now includes general supports for debugging applications on
3423 hybrid systems that use more than one single processor architecture
3424 at the same time. Each such hybrid architecture still requires
3425 specific support to be added. The only hybrid architecture supported
3426 in this version of GDB is the Cell Broadband Engine.
3428 * GDB now supports integrated debugging of Cell/B.E. applications that
3429 use both the PPU and SPU architectures. To enable support for hybrid
3430 Cell/B.E. debugging, you need to configure GDB to support both the
3431 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3432 --enable-targets configure option.
3434 * Non-stop mode debugging.
3436 For some targets, GDB now supports an optional mode of operation in
3437 which you can examine stopped threads while other threads continue
3438 to execute freely. This is referred to as non-stop mode, with the
3439 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3440 section in the user manual for more information.
3442 To be able to support remote non-stop debugging, a remote stub needs
3443 to implement the non-stop mode remote protocol extensions, as
3444 described in the "Remote Non-Stop" section of the user manual. The
3445 GDB remote stub, gdbserver, has been adjusted to support these
3446 extensions on linux targets.
3448 * New commands (for set/show, see "New options" below)
3450 catch syscall [NAME(S) | NUMBER(S)]
3451 Catch system calls. Arguments, which should be names of system
3452 calls or their numbers, mean catch only those syscalls. Without
3453 arguments, every syscall will be caught. When the inferior issues
3454 any of the specified syscalls, GDB will stop and announce the system
3455 call, both when it is called and when its call returns. This
3456 feature is currently available with a native GDB running on the
3457 Linux Kernel, under the following architectures: x86, x86_64,
3458 PowerPC and PowerPC64.
3460 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3462 Search memory for a sequence of bytes.
3464 maint set python print-stack
3465 maint show python print-stack
3466 Show a stack trace when an error is encountered in a Python script.
3469 Invoke CODE by passing it to the Python interpreter.
3474 These allow macros to be defined, undefined, and listed
3478 Show operating system information about processes.
3481 List the inferiors currently under GDB's control.
3484 Switch focus to inferior number NUM.
3487 Detach from inferior number NUM.
3490 Kill inferior number NUM.
3494 set spu stop-on-load
3495 show spu stop-on-load
3496 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3498 set spu auto-flush-cache
3499 show spu auto-flush-cache
3500 Control whether to automatically flush the software-managed cache
3501 during Cell/B.E. debugging.
3503 set sh calling-convention
3504 show sh calling-convention
3505 Control the calling convention used when calling SH target functions.
3508 show debug timestamp
3509 Control display of timestamps with GDB debugging output.
3511 set disassemble-next-line
3512 show disassemble-next-line
3513 Control display of disassembled source lines or instructions when
3516 set remote noack-packet
3517 show remote noack-packet
3518 Set/show the use of remote protocol QStartNoAckMode packet. See above
3519 under "New remote packets."
3521 set remote query-attached-packet
3522 show remote query-attached-packet
3523 Control use of remote protocol `qAttached' (query-attached) packet.
3525 set remote read-siginfo-object
3526 show remote read-siginfo-object
3527 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3530 set remote write-siginfo-object
3531 show remote write-siginfo-object
3532 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3535 set remote reverse-continue
3536 show remote reverse-continue
3537 Control use of remote protocol 'bc' (reverse-continue) packet.
3539 set remote reverse-step
3540 show remote reverse-step
3541 Control use of remote protocol 'bs' (reverse-step) packet.
3543 set displaced-stepping
3544 show displaced-stepping
3545 Control displaced stepping mode. Displaced stepping is a way to
3546 single-step over breakpoints without removing them from the debuggee.
3547 Also known as "out-of-line single-stepping".
3550 show debug displaced
3551 Control display of debugging info for displaced stepping.
3553 maint set internal-error
3554 maint show internal-error
3555 Control what GDB does when an internal error is detected.
3557 maint set internal-warning
3558 maint show internal-warning
3559 Control what GDB does when an internal warning is detected.
3564 Use a wrapper program to launch programs for debugging.
3566 set multiple-symbols (all|ask|cancel)
3567 show multiple-symbols
3568 The value of this variable can be changed to adjust the debugger behavior
3569 when an expression or a breakpoint location contains an ambiguous symbol
3570 name (an overloaded function name, for instance).
3572 set breakpoint always-inserted
3573 show breakpoint always-inserted
3574 Keep breakpoints always inserted in the target, as opposed to inserting
3575 them when resuming the target, and removing them when the target stops.
3576 This option can improve debugger performance on slow remote targets.
3578 set arm fallback-mode (arm|thumb|auto)
3579 show arm fallback-mode
3580 set arm force-mode (arm|thumb|auto)
3582 These commands control how ARM GDB determines whether instructions
3583 are ARM or Thumb. The default for both settings is auto, which uses
3584 the current CPSR value for instructions without symbols; previous
3585 versions of GDB behaved as if "set arm fallback-mode arm".
3587 set disable-randomization
3588 show disable-randomization
3589 Standalone programs run with the virtual address space randomization enabled
3590 by default on some platforms. This option keeps the addresses stable across
3591 multiple debugging sessions.
3595 Control whether other threads are stopped or not when some thread hits
3600 Requests that asynchronous execution is enabled in the target, if available.
3601 In this case, it's possible to resume target in the background, and interact
3602 with GDB while the target is running. "show target-async" displays the
3603 current state of asynchronous execution of the target.
3605 set target-wide-charset
3606 show target-wide-charset
3607 The target-wide-charset is the name of the character set that GDB
3608 uses when printing characters whose type is wchar_t.
3610 set tcp auto-retry (on|off)
3612 set tcp connect-timeout
3613 show tcp connect-timeout
3614 These commands allow GDB to retry failed TCP connections to a remote stub
3615 with a specified timeout period; this is useful if the stub is launched
3616 in parallel with GDB but may not be ready to accept connections immediately.
3618 set libthread-db-search-path
3619 show libthread-db-search-path
3620 Control list of directories which GDB will search for appropriate
3623 set schedule-multiple (on|off)
3624 show schedule-multiple
3625 Allow GDB to resume all threads of all processes or only threads of
3626 the current process.
3630 Use more aggressive caching for accesses to the stack. This improves
3631 performance of remote debugging (particularly backtraces) without
3632 affecting correctness.
3634 set interactive-mode (on|off|auto)
3635 show interactive-mode
3636 Control whether GDB runs in interactive mode (on) or not (off).
3637 When in interactive mode, GDB waits for the user to answer all
3638 queries. Otherwise, GDB does not wait and assumes the default
3639 answer. When set to auto (the default), GDB determines which
3640 mode to use based on the stdin settings.
3645 For program forks, this is replaced by the new more generic `info
3646 inferiors' command. To list checkpoints, you can still use the
3647 `info checkpoints' command, which was an alias for the `info forks'
3651 Replaced by the new `inferior' command. To switch between
3652 checkpoints, you can still use the `restart' command, which was an
3653 alias for the `fork' command.
3656 This is removed, since some targets don't have a notion of
3657 processes. To switch between processes, you can still use the
3658 `inferior' command using GDB's own inferior number.
3661 For program forks, this is replaced by the new more generic `kill
3662 inferior' command. To delete a checkpoint, you can still use the
3663 `delete checkpoint' command, which was an alias for the `delete
3667 For program forks, this is replaced by the new more generic `detach
3668 inferior' command. To detach a checkpoint, you can still use the
3669 `detach checkpoint' command, which was an alias for the `detach
3672 * New native configurations
3674 x86/x86_64 Darwin i[34567]86-*-darwin*
3676 x86_64 MinGW x86_64-*-mingw*
3680 Lattice Mico32 lm32-*
3681 x86 DICOS i[34567]86-*-dicos*
3682 x86_64 DICOS x86_64-*-dicos*
3685 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3686 (mingw32ce) debugging.
3692 These commands were actually not implemented on any target.
3694 *** Changes in GDB 6.8
3696 * New native configurations
3698 NetBSD/hppa hppa*-*netbsd*
3699 Xtensa GNU/Linux xtensa*-*-linux*
3703 NetBSD/hppa hppa*-*-netbsd*
3704 Xtensa GNU/Lunux xtensa*-*-linux*
3706 * Change in command line behavior -- corefiles vs. process ids.
3708 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3709 attaching to process NUMBER fails, GDB no longer attempts to open a
3710 core file named NUMBER. Attaching to a program using the -c option
3711 is no longer supported. Instead, use the '-p' or '--pid' options.
3713 * GDB can now be built as a native debugger for debugging Windows x86
3714 (mingw32) Portable Executable (PE) programs.
3716 * Pending breakpoints no longer change their number when their address
3719 * GDB now supports breakpoints with multiple locations,
3720 including breakpoints on C++ constructors, inside C++ templates,
3721 and in inlined functions.
3723 * GDB's ability to debug optimized code has been improved. GDB more
3724 accurately identifies function bodies and lexical blocks that occupy
3725 more than one contiguous range of addresses.
3727 * Target descriptions can now describe registers for PowerPC.
3729 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3730 registers on PowerPC targets.
3732 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3733 targets even when the libthread_db library is not available.
3735 * The GDB remote stub, gdbserver, now supports the new file transfer
3736 commands (remote put, remote get, and remote delete).
3738 * The GDB remote stub, gdbserver, now supports run and attach in
3739 extended-remote mode.
3741 * hppa*64*-*-hpux11* target broken
3742 The debugger is unable to start a program and fails with the following
3743 error: "Error trying to get information about dynamic linker".
3744 The gdb-6.7 release is also affected.
3746 * GDB now supports the --enable-targets= configure option to allow
3747 building a single GDB executable that supports multiple remote
3748 target architectures.
3750 * GDB now supports debugging C and C++ programs which use the
3751 Decimal Floating Point extension. In addition, the PowerPC target
3752 now has a set of pseudo-registers to inspect decimal float values
3753 stored in two consecutive float registers.
3755 * The -break-insert MI command can optionally create pending
3758 * Improved support for debugging Ada
3759 Many improvements to the Ada language support have been made. These
3761 - Better support for Ada2005 interface types
3762 - Improved handling of arrays and slices in general
3763 - Better support for Taft-amendment types
3764 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3766 - Improved command completion in Ada
3769 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3774 set print frame-arguments (all|scalars|none)
3775 show print frame-arguments
3776 The value of this variable can be changed to control which argument
3777 values should be printed by the debugger when displaying a frame.
3782 Transfer files to and from a remote target, and delete remote files.
3789 Transfer files to and from a remote target, and delete remote files.
3791 * New remote packets
3798 Open, close, read, write, and delete files on the remote system.
3801 Attach to an existing process on the remote system, in extended-remote
3805 Run a new process on the remote system, in extended-remote mode.
3807 *** Changes in GDB 6.7
3809 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3810 bfd, libiberty and opcodes, as revealed by static analysis donated by
3811 Coverity, Inc. (http://scan.coverity.com).
3813 * When looking up multiply-defined global symbols, GDB will now prefer the
3814 symbol definition in the current shared library if it was built using the
3815 -Bsymbolic linker option.
3817 * When the Text User Interface (TUI) is not configured, GDB will now
3818 recognize the -tui command-line option and print a message that the TUI
3821 * The GDB remote stub, gdbserver, now has lower overhead for high
3822 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3824 * GDB for MIPS targets now autodetects whether a remote target provides
3825 32-bit or 64-bit register values.
3827 * Support for C++ member pointers has been improved.
3829 * GDB now understands XML target descriptions, which specify the
3830 target's overall architecture. GDB can read a description from
3831 a local file or over the remote serial protocol.
3833 * Vectors of single-byte data use a new integer type which is not
3834 automatically displayed as character or string data.
3836 * The /s format now works with the print command. It displays
3837 arrays of single-byte integers and pointers to single-byte integers
3840 * Target descriptions can now describe target-specific registers,
3841 for architectures which have implemented the support (currently
3842 only ARM, M68K, and MIPS).
3844 * GDB and the GDB remote stub, gdbserver, now support the XScale
3847 * The GDB remote stub, gdbserver, has been updated to support
3848 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3849 has been rewritten to use the standard GDB remote protocol.
3851 * GDB can now step into C++ functions which are called through thunks.
3853 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3855 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3856 layout. It also supports a TextSeg= and DataSeg= response when only
3857 segment base addresses (rather than offsets) are available.
3859 * The /i format now outputs any trailing branch delay slot instructions
3860 immediately following the last instruction within the count specified.
3862 * The GDB remote protocol "T" stop reply packet now supports a
3863 "library" response. Combined with the new "qXfer:libraries:read"
3864 packet, this response allows GDB to debug shared libraries on targets
3865 where the operating system manages the list of loaded libraries (e.g.
3866 Windows and SymbianOS).
3868 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3869 (DLLs) on Windows and Windows CE targets.
3871 * GDB now supports a faster verification that a .debug file matches its binary
3872 according to its build-id signature, if the signature is present.
3878 Enable or disable hardware flow control (RTS/CTS) on the serial port
3879 when debugging using remote targets.
3881 set mem inaccessible-by-default
3882 show mem inaccessible-by-default
3883 If the target supplies a memory map, for instance via the remote
3884 protocol's "qXfer:memory-map:read" packet, setting this variable
3885 prevents GDB from accessing memory outside the memory map. This
3886 is useful for targets with memory mapped registers or which react
3887 badly to accesses of unmapped address space.
3889 set breakpoint auto-hw
3890 show breakpoint auto-hw
3891 If the target supplies a memory map, for instance via the remote
3892 protocol's "qXfer:memory-map:read" packet, setting this variable
3893 lets GDB use hardware breakpoints automatically for memory regions
3894 where it can not use software breakpoints. This covers both the
3895 "break" command and internal breakpoints used for other commands
3896 including "next" and "finish".
3899 catch exception unhandled
3900 Stop the program execution when Ada exceptions are raised.
3903 Stop the program execution when an Ada assertion failed.
3907 Set an alternate system root for target files. This is a more
3908 general version of "set solib-absolute-prefix", which is now
3909 an alias to "set sysroot".
3912 Provide extended SPU facility status information. This set of
3913 commands is available only when debugging the Cell/B.E. SPU
3916 * New native configurations
3918 OpenBSD/sh sh*-*openbsd*
3921 unset tdesc filename
3923 Use the specified local file as an XML target description, and do
3924 not query the target for its built-in description.
3928 OpenBSD/sh sh*-*-openbsd*
3929 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3930 Toshiba Media Processor mep-elf
3932 * New remote packets
3935 Ignore the specified signals; pass them directly to the debugged program
3936 without stopping other threads or reporting them to GDB.
3938 qXfer:features:read:
3939 Read an XML target description from the target, which describes its
3944 Read or write contents of an spufs file on the target system. These
3945 packets are available only on the Cell/B.E. SPU architecture.
3947 qXfer:libraries:read:
3948 Report the loaded shared libraries. Combined with new "T" packet
3949 response, this packet allows GDB to debug shared libraries on
3950 targets where the operating system manages the list of loaded
3951 libraries (e.g. Windows and SymbianOS).
3955 Support for these obsolete configurations has been removed.
3963 i[34567]86-*-lynxos*
3964 i[34567]86-*-netware*
3965 i[34567]86-*-sco3.2v5*
3966 i[34567]86-*-sco3.2v4*
3968 i[34567]86-*-sysv4.2*
3971 i[34567]86-*-unixware2*
3972 i[34567]86-*-unixware*
3981 * Other removed features
3988 Various m68k-only ROM monitors.
3995 Various Renesas ROM monitors and debugging interfaces for SH and
4000 Support for a Macraigor serial interface to on-chip debugging.
4001 GDB does not directly support the newer parallel or USB
4006 A debug information format. The predecessor to DWARF 2 and
4007 DWARF 3, which are still supported.
4009 Support for the HP aCC compiler on HP-UX/PA-RISC
4011 SOM-encapsulated symbolic debugging information, automatic
4012 invocation of pxdb, and the aCC custom C++ ABI. This does not
4013 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4014 with aCC can still be debugged on an assembly level.
4016 MIPS ".pdr" sections
4018 A MIPS-specific format used to describe stack frame layout
4019 in debugging information.
4023 GDB could work with an older version of Guile to debug
4024 the interpreter and Scheme programs running in it.
4026 set mips stack-arg-size
4027 set mips saved-gpreg-size
4029 Use "set mips abi" to control parameter passing for MIPS.
4031 *** Changes in GDB 6.6
4036 Cell Broadband Engine SPU spu-elf
4038 * GDB can now be configured as a cross-debugger targeting native Windows
4039 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4040 running on a Windows system over TCP/IP to debug Windows programs.
4042 * The GDB remote stub, gdbserver, has been updated to support Windows and
4043 Cygwin debugging. Both single-threaded and multi-threaded programs are
4046 * The "set trust-readonly-sections" command works again. This command was
4047 broken in GDB 6.3, 6.4, and 6.5.
4049 * The "load" command now supports writing to flash memory, if the remote
4050 stub provides the required support.
4052 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4053 longer requires symbolic debug information (e.g. DWARF-2).
4058 unset substitute-path
4059 show substitute-path
4060 Manage a list of substitution rules that GDB uses to rewrite the name
4061 of the directories where the sources are located. This can be useful
4062 for instance when the sources were moved to a different location
4063 between compilation and debugging.
4067 Print each CLI command as it is executed. Each command is prefixed with
4068 a number of `+' symbols representing the nesting depth.
4069 The source command now has a `-v' option to enable the same feature.
4073 The ARM Demon monitor support (RDP protocol, "target rdp").
4075 Kernel Object Display, an embedded debugging feature which only worked with
4076 an obsolete version of Cisco IOS.
4078 The 'set download-write-size' and 'show download-write-size' commands.
4080 * New remote packets
4083 Tell a stub about GDB client features, and request remote target features.
4084 The first feature implemented is PacketSize, which allows the target to
4085 specify the size of packets it can handle - to minimize the number of
4086 packets required and improve performance when connected to a remote
4090 Fetch an OS auxilliary vector from the remote stub. This packet is a
4091 more efficient replacement for qPart:auxv:read.
4093 qXfer:memory-map:read:
4094 Fetch a memory map from the remote stub, including information about
4095 RAM, ROM, and flash memory devices.
4100 Erase and program a flash memory device.
4102 * Removed remote packets
4105 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4106 used it, and only gdbserver implemented it.
4108 *** Changes in GDB 6.5
4112 Renesas M32C/M16C m32c-elf
4114 Morpho Technologies ms1 ms1-elf
4118 init-if-undefined Initialize a convenience variable, but
4119 only if it doesn't already have a value.
4121 The following commands are presently only implemented for native GNU/Linux:
4123 checkpoint Save a snapshot of the program state.
4125 restart <n> Return the program state to a
4126 previously saved state.
4128 info checkpoints List currently saved checkpoints.
4130 delete-checkpoint <n> Delete a previously saved checkpoint.
4132 set|show detach-on-fork Tell gdb whether to detach from a newly
4133 forked process, or to keep debugging it.
4135 info forks List forks of the user program that
4136 are available to be debugged.
4138 fork <n> Switch to debugging one of several
4139 forks of the user program that are
4140 available to be debugged.
4142 delete-fork <n> Delete a fork from the list of forks
4143 that are available to be debugged (and
4144 kill the forked process).
4146 detach-fork <n> Delete a fork from the list of forks
4147 that are available to be debugged (and
4148 allow the process to continue).
4152 Morpho Technologies ms2 ms1-elf
4154 * Improved Windows host support
4156 GDB now builds as a cross debugger hosted on i686-mingw32, including
4157 native console support, and remote communications using either
4158 network sockets or serial ports.
4160 * Improved Modula-2 language support
4162 GDB can now print most types in the Modula-2 syntax. This includes:
4163 basic types, set types, record types, enumerated types, range types,
4164 pointer types and ARRAY types. Procedure var parameters are correctly
4165 printed and hexadecimal addresses and character constants are also
4166 written in the Modula-2 syntax. Best results can be obtained by using
4167 GNU Modula-2 together with the -gdwarf-2 command line option.
4171 The ARM rdi-share module.
4173 The Netware NLM debug server.
4175 *** Changes in GDB 6.4
4177 * New native configurations
4179 OpenBSD/arm arm*-*-openbsd*
4180 OpenBSD/mips64 mips64-*-openbsd*
4184 Morpho Technologies ms1 ms1-elf
4186 * New command line options
4188 --batch-silent As for --batch, but totally silent.
4189 --return-child-result The debugger will exist with the same value
4190 the child (debugged) program exited with.
4191 --eval-command COMMAND, -ex COMMAND
4192 Execute a single GDB CLI command. This may be
4193 specified multiple times and in conjunction
4194 with the --command (-x) option.
4196 * Deprecated commands removed
4198 The following commands, that were deprecated in 2000, have been
4202 set|show arm disassembly-flavor set|show arm disassembler
4203 othernames set arm disassembler
4204 set|show remotedebug set|show debug remote
4205 set|show archdebug set|show debug arch
4206 set|show eventdebug set|show debug event
4209 * New BSD user-level threads support
4211 It is now possible to debug programs using the user-level threads
4212 library on OpenBSD and FreeBSD. Currently supported (target)
4215 FreeBSD/amd64 x86_64-*-freebsd*
4216 FreeBSD/i386 i386-*-freebsd*
4217 OpenBSD/i386 i386-*-openbsd*
4219 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4220 are not yet supported.
4222 * New support for Matsushita MN10300 w/sim added
4223 (Work in progress). mn10300-elf.
4225 * REMOVED configurations and files
4227 VxWorks and the XDR protocol *-*-vxworks
4228 Motorola MCORE mcore-*-*
4229 National Semiconductor NS32000 ns32k-*-*
4231 * New "set print array-indexes" command
4233 After turning this setting "on", GDB prints the index of each element
4234 when displaying arrays. The default is "off" to preserve the previous
4237 * VAX floating point support
4239 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4241 * User-defined command support
4243 In addition to using $arg0..$arg9 for argument passing, it is now possible
4244 to use $argc to determine now many arguments have been passed. See the
4245 section on user-defined commands in the user manual for more information.
4247 *** Changes in GDB 6.3:
4249 * New command line option
4251 GDB now accepts -l followed by a number to set the timeout for remote
4254 * GDB works with GCC -feliminate-dwarf2-dups
4256 GDB now supports a more compact representation of DWARF-2 debug
4257 information using DW_FORM_ref_addr references. These are produced
4258 by GCC with the option -feliminate-dwarf2-dups and also by some
4259 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4260 to use -feliminate-dwarf2-dups.
4262 * Internationalization
4264 When supported by the host system, GDB will be built with
4265 internationalization (libintl). The task of marking up the sources is
4266 continued, we're looking forward to our first translation.
4270 Initial support for debugging programs compiled with the GNAT
4271 implementation of the Ada programming language has been integrated
4272 into GDB. In this release, support is limited to expression evaluation.
4274 * New native configurations
4276 GNU/Linux/m32r m32r-*-linux-gnu
4280 GDB's remote protocol now includes support for the 'p' packet. This
4281 packet is used to fetch individual registers from a remote inferior.
4283 * END-OF-LIFE registers[] compatibility module
4285 GDB's internal register infrastructure has been completely rewritten.
4286 The new infrastructure making possible the implementation of key new
4287 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4290 GDB 6.3 will be the last release to include the the registers[]
4291 compatibility module that allowed out-of-date configurations to
4292 continue to work. This change directly impacts the following
4302 powerpc bdm protocol
4304 Unless there is activity to revive these configurations, they will be
4305 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4307 * OBSOLETE configurations and files
4309 Configurations that have been declared obsolete in this release have
4310 been commented out. Unless there is activity to revive these
4311 configurations, the next release of GDB will have their sources
4312 permanently REMOVED.
4321 *** Changes in GDB 6.2.1:
4323 * MIPS `break main; run' gave an heuristic-fence-post warning
4325 When attempting to run even a simple program, a warning about
4326 heuristic-fence-post being hit would be reported. This problem has
4329 * MIPS IRIX 'long double' crashed GDB
4331 When examining a long double variable, GDB would get a segmentation
4332 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4333 IRIX long double values).
4337 A bug in the VAX stack code was causing problems with the "next"
4338 command. This problem has been fixed.
4340 *** Changes in GDB 6.2:
4342 * Fix for ``many threads''
4344 On GNU/Linux systems that use the NPTL threads library, a program
4345 rapidly creating and deleting threads would confuse GDB leading to the
4348 ptrace: No such process.
4349 thread_db_get_info: cannot get thread info: generic error
4351 This problem has been fixed.
4353 * "-async" and "-noasync" options removed.
4355 Support for the broken "-noasync" option has been removed (it caused
4358 * New ``start'' command.
4360 This command runs the program until the begining of the main procedure.
4362 * New BSD Kernel Data Access Library (libkvm) interface
4364 Using ``target kvm'' it is now possible to debug kernel core dumps and
4365 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4366 platforms. Currently supported (native-only) configurations are:
4368 FreeBSD/amd64 x86_64-*-freebsd*
4369 FreeBSD/i386 i?86-*-freebsd*
4370 NetBSD/i386 i?86-*-netbsd*
4371 NetBSD/m68k m68*-*-netbsd*
4372 NetBSD/sparc sparc-*-netbsd*
4373 OpenBSD/amd64 x86_64-*-openbsd*
4374 OpenBSD/i386 i?86-*-openbsd*
4375 OpenBSD/m68k m68*-openbsd*
4376 OpenBSD/sparc sparc-*-openbsd*
4378 * Signal trampoline code overhauled
4380 Many generic problems with GDB's signal handling code have been fixed.
4381 These include: backtraces through non-contiguous stacks; recognition
4382 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4383 call; backtrace through a signal trampoline; step into and out of
4384 signal handlers; and single-stepping in the signal trampoline.
4386 Please note that kernel bugs are a limiting factor here. These
4387 features have been shown to work on an s390 GNU/Linux system that
4388 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4390 * Cygwin support for DWARF 2 added.
4392 * New native configurations
4394 GNU/Linux/hppa hppa*-*-linux*
4395 OpenBSD/hppa hppa*-*-openbsd*
4396 OpenBSD/m68k m68*-*-openbsd*
4397 OpenBSD/m88k m88*-*-openbsd*
4398 OpenBSD/powerpc powerpc-*-openbsd*
4399 NetBSD/vax vax-*-netbsd*
4400 OpenBSD/vax vax-*-openbsd*
4402 * END-OF-LIFE frame compatibility module
4404 GDB's internal frame infrastructure has been completely rewritten.
4405 The new infrastructure making it possible to support key new features
4406 including DWARF 2 Call Frame Information. To aid in the task of
4407 migrating old configurations to this new infrastructure, a
4408 compatibility module, that allowed old configurations to continue to
4409 work, was also included.
4411 GDB 6.2 will be the last release to include this frame compatibility
4412 module. This change directly impacts the following configurations:
4422 Unless there is activity to revive these configurations, they will be
4423 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4425 * REMOVED configurations and files
4427 Sun 3, running SunOS 3 m68*-*-sunos3*
4428 Sun 3, running SunOS 4 m68*-*-sunos4*
4429 Sun 2, running SunOS 3 m68000-*-sunos3*
4430 Sun 2, running SunOS 4 m68000-*-sunos4*
4431 Motorola 680x0 running LynxOS m68*-*-lynxos*
4432 AT&T 3b1/Unix pc m68*-att-*
4433 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4434 decstation mips-dec-* mips-little-*
4435 riscos mips-*-riscos* mips-*-sysv*
4436 sonymips mips-sony-*
4437 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4439 *** Changes in GDB 6.1.1:
4441 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4443 The TUI (Text-mode User Interface) is now built as part of a default
4444 GDB configuration. It is enabled by either selecting the TUI with the
4445 command line option "-i=tui" or by running the separate "gdbtui"
4446 program. For more information on the TUI, see the manual "Debugging
4449 * Pending breakpoint support (also included in GDB 6.1)
4451 Support has been added to allow you to specify breakpoints in shared
4452 libraries that have not yet been loaded. If a breakpoint location
4453 cannot be found, and the "breakpoint pending" option is set to auto,
4454 GDB queries you if you wish to make the breakpoint pending on a future
4455 shared-library load. If and when GDB resolves the breakpoint symbol,
4456 the pending breakpoint is removed as one or more regular breakpoints
4459 Pending breakpoints are very useful for GCJ Java debugging.
4461 * Fixed ISO-C build problems
4463 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4464 non ISO-C code that stopped them being built using a more strict ISO-C
4465 compiler (e.g., IBM's C compiler).
4467 * Fixed build problem on IRIX 5
4469 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4470 wasn't able to compile compile on an IRIX 5 system.
4472 * Added execute permission to gdb/gdbserver/configure
4474 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4475 permission. This bug would cause configure to fail on a number of
4476 systems (Solaris, IRIX). Ref: server/519.
4478 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4480 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4481 has been updated to use constant array sizes.
4483 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4485 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4486 its generated DWARF Call Frame Info. This encoding was causing GDB to
4487 panic, that panic has been fixed. Ref: gdb/1628.
4489 * Fixed a problem when examining parameters in shared library code.
4491 When examining parameters in optimized shared library code generated
4492 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4493 not available''. GDB now correctly displays the variable's value.
4495 *** Changes in GDB 6.1:
4497 * Removed --with-mmalloc
4499 Support for the mmalloc memory manager has been removed, as it
4500 conflicted with the internal gdb byte cache.
4502 * Changes in AMD64 configurations
4504 The AMD64 target now includes the %cs and %ss registers. As a result
4505 the AMD64 remote protocol has changed; this affects the floating-point
4506 and SSE registers. If you rely on those registers for your debugging,
4507 you should upgrade gdbserver on the remote side.
4509 * Revised SPARC target
4511 The SPARC target has been completely revised, incorporating the
4512 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4513 support for LynxOS and SunOS 4 has been dropped. Calling functions
4514 from within GDB on operating systems with a non-executable stack
4515 (Solaris, OpenBSD) now works.
4519 GDB has a new C++ demangler which does a better job on the mangled
4520 names generated by current versions of g++. It also runs faster, so
4521 with this and other changes gdb should now start faster on large C++
4524 * DWARF 2 Location Expressions
4526 GDB support for location expressions has been extended to support function
4527 arguments and frame bases. Older versions of GDB could crash when they
4530 * C++ nested types and namespaces
4532 GDB's support for nested types and namespaces in C++ has been
4533 improved, especially if you use the DWARF 2 debugging format. (This
4534 is the default for recent versions of GCC on most platforms.)
4535 Specifically, if you have a class "Inner" defined within a class or
4536 namespace "Outer", then GDB realizes that the class's name is
4537 "Outer::Inner", not simply "Inner". This should greatly reduce the
4538 frequency of complaints about not finding RTTI symbols. In addition,
4539 if you are stopped at inside of a function defined within a namespace,
4540 GDB modifies its name lookup accordingly.
4542 * New native configurations
4544 NetBSD/amd64 x86_64-*-netbsd*
4545 OpenBSD/amd64 x86_64-*-openbsd*
4546 OpenBSD/alpha alpha*-*-openbsd*
4547 OpenBSD/sparc sparc-*-openbsd*
4548 OpenBSD/sparc64 sparc64-*-openbsd*
4550 * New debugging protocols
4552 M32R with SDI protocol m32r-*-elf*
4554 * "set prompt-escape-char" command deleted.
4556 The command "set prompt-escape-char" has been deleted. This command,
4557 and its very obscure effet on GDB's prompt, was never documented,
4558 tested, nor mentioned in the NEWS file.
4560 * OBSOLETE configurations and files
4562 Configurations that have been declared obsolete in this release have
4563 been commented out. Unless there is activity to revive these
4564 configurations, the next release of GDB will have their sources
4565 permanently REMOVED.
4567 Sun 3, running SunOS 3 m68*-*-sunos3*
4568 Sun 3, running SunOS 4 m68*-*-sunos4*
4569 Sun 2, running SunOS 3 m68000-*-sunos3*
4570 Sun 2, running SunOS 4 m68000-*-sunos4*
4571 Motorola 680x0 running LynxOS m68*-*-lynxos*
4572 AT&T 3b1/Unix pc m68*-att-*
4573 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4574 decstation mips-dec-* mips-little-*
4575 riscos mips-*-riscos* mips-*-sysv*
4576 sonymips mips-sony-*
4577 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4579 * REMOVED configurations and files
4581 SGI Irix-4.x mips-sgi-irix4 or iris4
4582 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4583 Z8000 simulator z8k-zilog-none or z8ksim
4584 Matsushita MN10200 w/simulator mn10200-*-*
4585 H8/500 simulator h8500-hitachi-hms or h8500hms
4586 HP/PA running BSD hppa*-*-bsd*
4587 HP/PA running OSF/1 hppa*-*-osf*
4588 HP/PA Pro target hppa*-*-pro*
4589 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4590 386BSD i[3456]86-*-bsd*
4591 Sequent family i[3456]86-sequent-sysv4*
4592 i[3456]86-sequent-sysv*
4593 i[3456]86-sequent-bsd*
4594 SPARC running LynxOS sparc-*-lynxos*
4595 SPARC running SunOS 4 sparc-*-sunos4*
4596 Tsqware Sparclet sparclet-*-*
4597 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4599 *** Changes in GDB 6.0:
4603 Support for debugging the Objective-C programming language has been
4604 integrated into GDB.
4606 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4608 DWARF 2's Call Frame Information makes available compiler generated
4609 information that more exactly describes the program's run-time stack.
4610 By using this information, GDB is able to provide more robust stack
4613 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4614 have been updated to use a new backtrace mechanism which includes
4615 DWARF 2 CFI support.
4619 GDB's remote protocol has been extended to include support for hosted
4620 file I/O (where the remote target uses GDB's file system). See GDB's
4621 remote protocol documentation for details.
4623 * All targets using the new architecture framework.
4625 All of GDB's targets have been updated to use the new internal
4626 architecture framework. The way is now open for future GDB releases
4627 to include cross-architecture native debugging support (i386 on amd64,
4630 * GNU/Linux's Thread Local Storage (TLS)
4632 GDB now includes support for for the GNU/Linux implementation of
4633 per-thread variables.
4635 * GNU/Linux's Native POSIX Thread Library (NPTL)
4637 GDB's thread code has been updated to work with either the new
4638 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4640 * Separate debug info.
4642 GDB, in conjunction with BINUTILS, now supports a mechanism for
4643 automatically loading debug information from a separate file. Instead
4644 of shipping full debug and non-debug versions of system libraries,
4645 system integrators can now instead ship just the stripped libraries
4646 and optional debug files.
4648 * DWARF 2 Location Expressions
4650 DWARF 2 Location Expressions allow the compiler to more completely
4651 describe the location of variables (even in optimized code) to the
4654 GDB now includes preliminary support for location expressions (support
4655 for DW_OP_piece is still missing).
4659 A number of long standing bugs that caused GDB to die while starting a
4660 Java application have been fixed. GDB's Java support is now
4661 considered "useable".
4663 * GNU/Linux support for fork, vfork, and exec.
4665 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4666 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4669 * GDB supports logging output to a file
4671 There are two new commands, "set logging" and "show logging", which can be
4672 used to capture GDB's output to a file.
4674 * The meaning of "detach" has changed for gdbserver
4676 The "detach" command will now resume the application, as documented. To
4677 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4680 * d10v, m68hc11 `regs' command deprecated
4682 The `info registers' command has been updated so that it displays the
4683 registers using a format identical to the old `regs' command.
4687 A new command, "maint set profile on/off", has been added. This command can
4688 be used to enable or disable profiling while running GDB, to profile a
4689 session or a set of commands. In addition there is a new configure switch,
4690 "--enable-profiling", which will cause GDB to be compiled with profiling
4691 data, for more informative profiling results.
4693 * Default MI syntax changed to "mi2".
4695 The default MI (machine interface) syntax, enabled by the command line
4696 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4697 "mi1", can be enabled by specifying the option "-i=mi1".
4699 Support for the original "mi0" syntax (included in GDB 5.0) has been
4702 Fix for gdb/192: removed extraneous space when displaying frame level.
4703 Fix for gdb/672: update changelist is now output in mi list format.
4704 Fix for gdb/702: a -var-assign that updates the value now shows up
4705 in a subsequent -var-update.
4707 * New native configurations.
4709 FreeBSD/amd64 x86_64-*-freebsd*
4711 * Multi-arched targets.
4713 HP/PA HPUX11 hppa*-*-hpux*
4714 Renesas M32R/D w/simulator m32r-*-elf*
4716 * OBSOLETE configurations and files
4718 Configurations that have been declared obsolete in this release have
4719 been commented out. Unless there is activity to revive these
4720 configurations, the next release of GDB will have their sources
4721 permanently REMOVED.
4723 Z8000 simulator z8k-zilog-none or z8ksim
4724 Matsushita MN10200 w/simulator mn10200-*-*
4725 H8/500 simulator h8500-hitachi-hms or h8500hms
4726 HP/PA running BSD hppa*-*-bsd*
4727 HP/PA running OSF/1 hppa*-*-osf*
4728 HP/PA Pro target hppa*-*-pro*
4729 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4730 Sequent family i[3456]86-sequent-sysv4*
4731 i[3456]86-sequent-sysv*
4732 i[3456]86-sequent-bsd*
4733 Tsqware Sparclet sparclet-*-*
4734 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4736 * REMOVED configurations and files
4739 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4740 IBM AIX PS/2 i[3456]86-*-aix
4741 i386 running Mach 3.0 i[3456]86-*-mach3*
4742 i386 running Mach i[3456]86-*-mach*
4743 i386 running OSF/1 i[3456]86-*osf1mk*
4744 HP/Apollo 68k Family m68*-apollo*-sysv*,
4746 m68*-hp-bsd*, m68*-hp-hpux*
4747 Argonaut Risc Chip (ARC) arc-*-*
4748 Mitsubishi D30V d30v-*-*
4749 Fujitsu FR30 fr30-*-elf*
4750 OS/9000 i[34]86-*-os9k
4751 I960 with MON960 i960-*-coff
4753 * MIPS $fp behavior changed
4755 The convenience variable $fp, for the MIPS, now consistently returns
4756 the address of the current frame's base. Previously, depending on the
4757 context, $fp could refer to either $sp or the current frame's base
4758 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4759 The GNU Source-Level Debugger''.
4761 *** Changes in GDB 5.3:
4763 * GNU/Linux shared library multi-threaded performance improved.
4765 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4766 `/proc', in preference to `ptrace' for memory reads. This may result
4767 in an improvement in the start-up time of multi-threaded, shared
4768 library applications when run under GDB. One GDB user writes: ``loads
4769 shared libs like mad''.
4771 * ``gdbserver'' now supports multi-threaded applications on some targets
4773 Support for debugging multi-threaded applications which use
4774 the GNU/Linux LinuxThreads package has been added for
4775 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4776 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4778 * GDB now supports C/C++ preprocessor macros.
4780 GDB now expands preprocessor macro invocations in C/C++ expressions,
4781 and provides various commands for showing macro definitions and how
4784 The new command `macro expand EXPRESSION' expands any macro
4785 invocations in expression, and shows the result.
4787 The new command `show macro MACRO-NAME' shows the definition of the
4788 macro named MACRO-NAME, and where it was defined.
4790 Most compilers don't include information about macros in the debugging
4791 information by default. In GCC 3.1, for example, you need to compile
4792 your program with the options `-gdwarf-2 -g3'. If the macro
4793 information is present in the executable, GDB will read it.
4795 * Multi-arched targets.
4797 DEC Alpha (partial) alpha*-*-*
4798 DEC VAX (partial) vax-*-*
4800 National Semiconductor NS32000 (partial) ns32k-*-*
4801 Motorola 68000 (partial) m68k-*-*
4802 Motorola MCORE mcore-*-*
4806 Fujitsu FRV architecture added by Red Hat frv*-*-*
4809 * New native configurations
4811 Alpha NetBSD alpha*-*-netbsd*
4812 SH NetBSD sh*-*-netbsdelf*
4813 MIPS NetBSD mips*-*-netbsd*
4814 UltraSPARC NetBSD sparc64-*-netbsd*
4816 * OBSOLETE configurations and files
4818 Configurations that have been declared obsolete in this release have
4819 been commented out. Unless there is activity to revive these
4820 configurations, the next release of GDB will have their sources
4821 permanently REMOVED.
4823 Mitsubishi D30V d30v-*-*
4824 OS/9000 i[34]86-*-os9k
4825 IBM AIX PS/2 i[3456]86-*-aix
4826 Fujitsu FR30 fr30-*-elf*
4827 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4828 Argonaut Risc Chip (ARC) arc-*-*
4829 i386 running Mach 3.0 i[3456]86-*-mach3*
4830 i386 running Mach i[3456]86-*-mach*
4831 i386 running OSF/1 i[3456]86-*osf1mk*
4832 HP/Apollo 68k Family m68*-apollo*-sysv*,
4834 m68*-hp-bsd*, m68*-hp-hpux*
4835 I960 with MON960 i960-*-coff
4837 * OBSOLETE languages
4839 CHILL, a Pascal like language used by telecommunications companies.
4841 * REMOVED configurations and files
4843 AMD 29k family via UDI a29k-amd-udi, udi29k
4844 A29K VxWorks a29k-*-vxworks
4845 AMD 29000 embedded, using EBMON a29k-none-none
4846 AMD 29000 embedded with COFF a29k-none-coff
4847 AMD 29000 embedded with a.out a29k-none-aout
4849 testsuite/gdb.hp/gdb.threads-hp/ directory
4851 * New command "set max-user-call-depth <nnn>"
4853 This command allows the user to limit the call depth of user-defined
4854 commands. The default is 1024.
4856 * Changes in FreeBSD/i386 native debugging.
4858 Support for the "generate-core-file" has been added.
4860 * New commands "dump", "append", and "restore".
4862 These commands allow data to be copied from target memory
4863 to a bfd-format or binary file (dump and append), and back
4864 from a file into memory (restore).
4866 * Improved "next/step" support on multi-processor Alpha Tru64.
4868 The previous single-step mechanism could cause unpredictable problems,
4869 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4870 of a software single-step mechanism prevents this.
4872 *** Changes in GDB 5.2.1:
4880 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4881 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4882 Fix, by Joel Brobecker imported from mainline.
4884 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4885 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4886 Fix, by Fred Fish, imported from mainline.
4888 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4889 Surprisingly enough, it works now.
4890 By Michal Ludvig, imported from mainline.
4892 i386 hardware watchpoint support:
4893 avoid misses on second run for some targets.
4894 By Pierre Muller, imported from mainline.
4896 *** Changes in GDB 5.2:
4898 * New command "set trust-readonly-sections on[off]".
4900 This command is a hint that tells gdb that read-only sections
4901 really are read-only (ie. that their contents will not change).
4902 In this mode, gdb will go to the object file rather than the
4903 target to read memory from read-only sections (such as ".text").
4904 This can be a significant performance improvement on some
4905 (notably embedded) targets.
4907 * New command "generate-core-file" (or "gcore").
4909 This new gdb command allows the user to drop a core file of the child
4910 process state at any time. So far it's been implemented only for
4911 GNU/Linux and Solaris, but should be relatively easily ported to other
4912 hosts. Argument is core file name (defaults to core.<pid>).
4914 * New command line option
4916 GDB now accepts --pid or -p followed by a process id.
4918 * Change in command line behavior -- corefiles vs. process ids.
4920 There is a subtle behavior in the way in which GDB handles
4921 command line arguments. The first non-flag argument is always
4922 a program to debug, but the second non-flag argument may either
4923 be a corefile or a process id. Previously, GDB would attempt to
4924 open the second argument as a corefile, and if that failed, would
4925 issue a superfluous error message and then attempt to attach it as
4926 a process. Now, if the second argument begins with a non-digit,
4927 it will be treated as a corefile. If it begins with a digit,
4928 GDB will attempt to attach it as a process, and if no such process
4929 is found, will then attempt to open it as a corefile.
4931 * Changes in ARM configurations.
4933 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4934 configuration is fully multi-arch.
4936 * New native configurations
4938 ARM NetBSD arm*-*-netbsd*
4939 x86 OpenBSD i[3456]86-*-openbsd*
4940 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4941 Sparc64 running FreeBSD sparc64-*-freebsd*
4945 Sanyo XStormy16 xstormy16-elf
4947 * OBSOLETE configurations and files
4949 Configurations that have been declared obsolete in this release have
4950 been commented out. Unless there is activity to revive these
4951 configurations, the next release of GDB will have their sources
4952 permanently REMOVED.
4954 AMD 29k family via UDI a29k-amd-udi, udi29k
4955 A29K VxWorks a29k-*-vxworks
4956 AMD 29000 embedded, using EBMON a29k-none-none
4957 AMD 29000 embedded with COFF a29k-none-coff
4958 AMD 29000 embedded with a.out a29k-none-aout
4960 testsuite/gdb.hp/gdb.threads-hp/ directory
4962 * REMOVED configurations and files
4964 TI TMS320C80 tic80-*-*
4966 PowerPC Solaris powerpcle-*-solaris*
4967 PowerPC Windows NT powerpcle-*-cygwin32
4968 PowerPC Netware powerpc-*-netware*
4969 Harris/CXUX m88k m88*-harris-cxux*
4970 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4971 ns32k-utek-sysv* ns32k-utek-*
4972 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4973 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4974 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4975 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4976 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4978 * Changes to command line processing
4980 The new `--args' feature can be used to specify command-line arguments
4981 for the inferior from gdb's command line.
4983 * Changes to key bindings
4985 There is a new `operate-and-get-next' function bound to `C-o'.
4987 *** Changes in GDB 5.1.1
4989 Fix compile problem on DJGPP.
4991 Fix a problem with floating-point registers on the i386 being
4994 Fix to stop GDB crashing on .debug_str debug info.
4996 Numerous documentation fixes.
4998 Numerous testsuite fixes.
5000 *** Changes in GDB 5.1:
5002 * New native configurations
5004 Alpha FreeBSD alpha*-*-freebsd*
5005 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5006 MIPS GNU/Linux mips*-*-linux*
5007 MIPS SGI Irix 6.x mips*-sgi-irix6*
5008 ia64 AIX ia64-*-aix*
5009 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5013 Motorola 68HC11 and 68HC12 m68hc11-elf
5015 UltraSparc running GNU/Linux sparc64-*-linux*
5017 * OBSOLETE configurations and files
5019 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5020 Harris/CXUX m88k m88*-harris-cxux*
5021 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5022 ns32k-utek-sysv* ns32k-utek-*
5023 TI TMS320C80 tic80-*-*
5025 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5026 PowerPC Solaris powerpcle-*-solaris*
5027 PowerPC Windows NT powerpcle-*-cygwin32
5028 PowerPC Netware powerpc-*-netware*
5029 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5030 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5031 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5032 Apple Macintosh (MPW) host N/A
5034 stuff.c (Program to stuff files into a specially prepared space in kdb)
5035 kdb-start.c (Main loop for the standalone kernel debugger)
5037 Configurations that have been declared obsolete in this release have
5038 been commented out. Unless there is activity to revive these
5039 configurations, the next release of GDB will have their sources
5040 permanently REMOVED.
5042 * REMOVED configurations and files
5044 Altos 3068 m68*-altos-*
5045 Convex c1-*-*, c2-*-*
5047 ARM RISCix arm-*-* (as host)
5051 * GDB has been converted to ISO C.
5053 GDB's source code has been converted to ISO C. In particular, the
5054 sources are fully protoized, and rely on standard headers being
5059 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5061 * The MI enabled by default.
5063 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5064 revised and enabled by default. Packages which use GDB as a debugging
5065 engine behind a UI or another front end are encouraged to switch to
5066 using the GDB/MI interface, instead of the old annotations interface
5067 which is now deprecated.
5069 * Support for debugging Pascal programs.
5071 GDB now includes support for debugging Pascal programs. The following
5072 main features are supported:
5074 - Pascal-specific data types such as sets;
5076 - automatic recognition of Pascal sources based on file-name
5079 - Pascal-style display of data types, variables, and functions;
5081 - a Pascal expression parser.
5083 However, some important features are not yet supported.
5085 - Pascal string operations are not supported at all;
5087 - there are some problems with boolean types;
5089 - Pascal type hexadecimal constants are not supported
5090 because they conflict with the internal variables format;
5092 - support for Pascal objects and classes is not full yet;
5094 - unlike Pascal, GDB is case-sensitive for symbol names.
5096 * Changes in completion.
5098 Commands such as `shell', `run' and `set args', which pass arguments
5099 to inferior programs, now complete on file names, similar to what
5100 users expect at the shell prompt.
5102 Commands which accept locations, such as `disassemble', `print',
5103 `breakpoint', `until', etc. now complete on filenames as well as
5104 program symbols. Thus, if you type "break foob TAB", and the source
5105 files linked into the programs include `foobar.c', that file name will
5106 be one of the candidates for completion. However, file names are not
5107 considered for completion after you typed a colon that delimits a file
5108 name from a name of a function in that file, as in "break foo.c:bar".
5110 `set demangle-style' completes on available demangling styles.
5112 * New platform-independent commands:
5114 It is now possible to define a post-hook for a command as well as a
5115 hook that runs before the command. For more details, see the
5116 documentation of `hookpost' in the GDB manual.
5118 * Changes in GNU/Linux native debugging.
5120 Support for debugging multi-threaded programs has been completely
5121 revised for all platforms except m68k and sparc. You can now debug as
5122 many threads as your system allows you to have.
5124 Attach/detach is supported for multi-threaded programs.
5126 Support for SSE registers was added for x86. This doesn't work for
5127 multi-threaded programs though.
5129 * Changes in MIPS configurations.
5131 Multi-arch support is enabled for all MIPS configurations.
5133 GDB can now be built as native debugger on SGI Irix 6.x systems for
5134 debugging n32 executables. (Debugging 64-bit executables is not yet
5137 * Unified support for hardware watchpoints in all x86 configurations.
5139 Most (if not all) native x86 configurations support hardware-assisted
5140 breakpoints and watchpoints in a unified manner. This support
5141 implements debug register sharing between watchpoints, which allows to
5142 put a virtually infinite number of watchpoints on the same address,
5143 and also supports watching regions up to 16 bytes with several debug
5146 The new maintenance command `maintenance show-debug-regs' toggles
5147 debugging print-outs in functions that insert, remove, and test
5148 watchpoints and hardware breakpoints.
5150 * Changes in the DJGPP native configuration.
5152 New command ``info dos sysinfo'' displays assorted information about
5153 the CPU, OS, memory, and DPMI server.
5155 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5156 display information about segment descriptors stored in GDT, LDT, and
5159 New commands ``info dos pde'' and ``info dos pte'' display entries
5160 from Page Directory and Page Tables (for now works with CWSDPMI only).
5161 New command ``info dos address-pte'' displays the Page Table entry for
5162 a given linear address.
5164 GDB can now pass command lines longer than 126 characters to the
5165 program being debugged (requires an update to the libdbg.a library
5166 which is part of the DJGPP development kit).
5168 DWARF2 debug info is now supported.
5170 It is now possible to `step' and `next' through calls to `longjmp'.
5172 * Changes in documentation.
5174 All GDB documentation was converted to GFDL, the GNU Free
5175 Documentation License.
5177 Tracepoints-related commands are now fully documented in the GDB
5180 TUI, the Text-mode User Interface, is now documented in the manual.
5182 Tracepoints-related commands are now fully documented in the GDB
5185 The "GDB Internals" manual now has an index. It also includes
5186 documentation of `ui_out' functions, GDB coding standards, x86
5187 hardware watchpoints, and memory region attributes.
5189 * GDB's version number moved to ``version.in''
5191 The Makefile variable VERSION has been replaced by the file
5192 ``version.in''. People creating GDB distributions should update the
5193 contents of this file.
5197 GUD support is now a standard part of the EMACS distribution.
5199 *** Changes in GDB 5.0:
5201 * Improved support for debugging FP programs on x86 targets
5203 Unified and much-improved support for debugging floating-point
5204 programs on all x86 targets. In particular, ``info float'' now
5205 displays the FP registers in the same format on all x86 targets, with
5206 greater level of detail.
5208 * Improvements and bugfixes in hardware-assisted watchpoints
5210 It is now possible to watch array elements, struct members, and
5211 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5212 on x86 targets no longer erroneously trigger when the address is
5215 * Improvements in the native DJGPP version of GDB
5217 The distribution now includes all the scripts and auxiliary files
5218 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5219 machines ``out of the box''.
5221 The DJGPP version can now debug programs that use signals. It is
5222 possible to catch signals that happened in the debuggee, deliver
5223 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5224 would kill the program being debugged.) Programs that hook hardware
5225 interrupts (keyboard, timer, etc.) can also be debugged.
5227 It is now possible to debug DJGPP programs that redirect their
5228 standard handles or switch them to raw (as opposed to cooked) mode, or
5229 even close them. The command ``run < foo > bar'' works as expected,
5230 and ``info terminal'' reports useful information about the debuggee's
5231 terminal, including raw/cooked mode, redirection, etc.
5233 The DJGPP version now uses termios functions for console I/O, which
5234 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5237 DOS-style file names with drive letters are now fully supported by
5240 It is now possible to debug DJGPP programs that switch their working
5241 directory. It is also possible to rerun the debuggee any number of
5242 times without restarting GDB; thus, you can use the same setup,
5243 breakpoints, etc. for many debugging sessions.
5245 * New native configurations
5247 ARM GNU/Linux arm*-*-linux*
5248 PowerPC GNU/Linux powerpc-*-linux*
5252 Motorola MCore mcore-*-*
5253 x86 VxWorks i[3456]86-*-vxworks*
5254 PowerPC VxWorks powerpc-*-vxworks*
5255 TI TMS320C80 tic80-*-*
5257 * OBSOLETE configurations
5259 Altos 3068 m68*-altos-*
5260 Convex c1-*-*, c2-*-*
5262 ARM RISCix arm-*-* (as host)
5265 Configurations that have been declared obsolete will be commented out,
5266 but the code will be left in place. If there is no activity to revive
5267 these configurations before the next release of GDB, the sources will
5268 be permanently REMOVED.
5270 * Gould support removed
5272 Support for the Gould PowerNode and NP1 has been removed.
5274 * New features for SVR4
5276 On SVR4 native platforms (such as Solaris), if you attach to a process
5277 without first loading a symbol file, GDB will now attempt to locate and
5278 load symbols from the running process's executable file.
5280 * Many C++ enhancements
5282 C++ support has been greatly improved. Overload resolution now works properly
5283 in almost all cases. RTTI support is on the way.
5285 * Remote targets can connect to a sub-program
5287 A popen(3) style serial-device has been added. This device starts a
5288 sub-process (such as a stand-alone simulator) and then communicates
5289 with that. The sub-program to run is specified using the syntax
5290 ``|<program> <args>'' vis:
5292 (gdb) set remotedebug 1
5293 (gdb) target extended-remote |mn10300-elf-sim program-args
5295 * MIPS 64 remote protocol
5297 A long standing bug in the mips64 remote protocol where by GDB
5298 expected certain 32 bit registers (ex SR) to be transfered as 32
5299 instead of 64 bits has been fixed.
5301 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5302 added to provide backward compatibility with older versions of GDB.
5304 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5306 The command ``set remotebinarydownload'' command has been replaced by
5307 ``set remote X-packet''. Other commands in ``set remote'' family
5308 include ``set remote P-packet''.
5310 * Breakpoint commands accept ranges.
5312 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5313 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5314 ``tracepoint passcount'' also accepts a range of tracepoints.
5316 * ``apropos'' command added.
5318 The ``apropos'' command searches through command names and
5319 documentation strings, printing out matches, making it much easier to
5320 try to find a command that does what you are looking for.
5324 A new machine oriented interface (MI) has been added to GDB. This
5325 interface is designed for debug environments running GDB as a separate
5326 process. This is part of the long term libGDB project. See the
5327 "GDB/MI" chapter of the GDB manual for further information. It can be
5328 enabled by configuring with:
5330 .../configure --enable-gdbmi
5332 *** Changes in GDB-4.18:
5334 * New native configurations
5336 HP-UX 10.20 hppa*-*-hpux10.20
5337 HP-UX 11.x hppa*-*-hpux11.0*
5338 M68K GNU/Linux m68*-*-linux*
5342 Fujitsu FR30 fr30-*-elf*
5343 Intel StrongARM strongarm-*-*
5344 Mitsubishi D30V d30v-*-*
5346 * OBSOLETE configurations
5348 Gould PowerNode, NP1 np1-*-*, pn-*-*
5350 Configurations that have been declared obsolete will be commented out,
5351 but the code will be left in place. If there is no activity to revive
5352 these configurations before the next release of GDB, the sources will
5353 be permanently REMOVED.
5357 As a compatibility experiment, GDB's source files buildsym.h and
5358 buildsym.c have been converted to pure standard C, no longer
5359 containing any K&R compatibility code. We believe that all systems in
5360 use today either come with a standard C compiler, or have a GCC port
5361 available. If this is not true, please report the affected
5362 configuration to bug-gdb@gnu.org immediately. See the README file for
5363 information about getting a standard C compiler if you don't have one
5368 GDB now uses readline 2.2.
5370 * set extension-language
5372 You can now control the mapping between filename extensions and source
5373 languages by using the `set extension-language' command. For instance,
5374 you can ask GDB to treat .c files as C++ by saying
5375 set extension-language .c c++
5376 The command `info extensions' lists all of the recognized extensions
5377 and their associated languages.
5379 * Setting processor type for PowerPC and RS/6000
5381 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5382 you can use the `set processor' command to specify what variant of the
5383 PowerPC family you are debugging. The command
5387 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5388 following PowerPC and RS6000 variants:
5390 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5391 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5393 403GC IBM PowerPC 403GC
5394 505 Motorola PowerPC 505
5395 860 Motorola PowerPC 860 or 850
5396 601 Motorola PowerPC 601
5397 602 Motorola PowerPC 602
5398 603 Motorola/IBM PowerPC 603 or 603e
5399 604 Motorola PowerPC 604 or 604e
5400 750 Motorola/IBM PowerPC 750 or 750
5402 At the moment, this command just tells GDB what to name the
5403 special-purpose processor registers. Since almost all the affected
5404 registers are inaccessible to user-level programs, this command is
5405 only useful for remote debugging in its present form.
5409 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5410 more extensive support for HP-UX. Added features include shared
5411 library support, kernel threads and hardware watchpoints for 11.00,
5412 support for HP's ANSI C and C++ compilers, and a compatibility mode
5413 for xdb and dbx commands.
5417 HP's donation includes the new concept of catchpoints, which is a
5418 generalization of the old catch command. On HP-UX, it is now possible
5419 to catch exec, fork, and vfork, as well as library loading.
5421 This means that the existing catch command has changed; its first
5422 argument now specifies the type of catch to be set up. See the
5423 output of "help catch" for a list of catchpoint types.
5425 * Debugging across forks
5427 On HP-UX, you can choose which process to debug when a fork() happens
5432 HP has donated a curses-based terminal user interface (TUI). To get
5433 it, build with --enable-tui. Although this can be enabled for any
5434 configuration, at present it only works for native HP debugging.
5436 * GDB remote protocol additions
5438 A new protocol packet 'X' that writes binary data is now available.
5439 Default behavior is to try 'X', then drop back to 'M' if the stub
5440 fails to respond. The settable variable `remotebinarydownload'
5441 allows explicit control over the use of 'X'.
5443 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5444 full 64-bit address. The command
5446 set remoteaddresssize 32
5448 can be used to revert to the old behaviour. For existing remote stubs
5449 the change should not be noticed, as the additional address information
5452 In order to assist in debugging stubs, you may use the maintenance
5453 command `packet' to send any text string to the stub. For instance,
5455 maint packet heythere
5457 sends the packet "$heythere#<checksum>". Note that it is very easy to
5458 disrupt a debugging session by sending the wrong packet at the wrong
5461 The compare-sections command allows you to compare section data on the
5462 target to what is in the executable file without uploading or
5463 downloading, by comparing CRC checksums.
5465 * Tracing can collect general expressions
5467 You may now collect general expressions at tracepoints. This requires
5468 further additions to the target-side stub; see tracepoint.c and
5469 doc/agentexpr.texi for further details.
5471 * mask-address variable for Mips
5473 For Mips targets, you may control the zeroing of the upper 32 bits of
5474 a 64-bit address by entering `set mask-address on'. This is mainly
5475 of interest to users of embedded R4xxx and R5xxx processors.
5477 * Higher serial baud rates
5479 GDB's serial code now allows you to specify baud rates 57600, 115200,
5480 230400, and 460800 baud. (Note that your host system may not be able
5481 to achieve all of these rates.)
5485 The i960 configuration now includes an initial implementation of a
5486 builtin simulator, contributed by Jim Wilson.
5489 *** Changes in GDB-4.17:
5491 * New native configurations
5493 Alpha GNU/Linux alpha*-*-linux*
5494 Unixware 2.x i[3456]86-unixware2*
5495 Irix 6.x mips*-sgi-irix6*
5496 PowerPC GNU/Linux powerpc-*-linux*
5497 PowerPC Solaris powerpcle-*-solaris*
5498 Sparc GNU/Linux sparc-*-linux*
5499 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5503 Argonaut Risc Chip (ARC) arc-*-*
5504 Hitachi H8/300S h8300*-*-*
5505 Matsushita MN10200 w/simulator mn10200-*-*
5506 Matsushita MN10300 w/simulator mn10300-*-*
5507 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5508 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5509 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5510 Mitsubishi D10V w/simulator d10v-*-*
5511 Mitsubishi M32R/D w/simulator m32r-*-elf*
5512 Tsqware Sparclet sparclet-*-*
5513 NEC V850 w/simulator v850-*-*
5515 * New debugging protocols
5517 ARM with RDI protocol arm*-*-*
5518 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5519 DDB and LSI variants of PMON protocol mips*-*-*
5520 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5521 PowerPC with SDS protocol powerpc{,le}-*-eabi
5522 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5526 All configurations can now understand and use the DWARF 2 debugging
5527 format. The choice is automatic, if the symbol file contains DWARF 2
5532 GDB now includes basic Java language support. This support is
5533 only useful with Java compilers that produce native machine code.
5535 * solib-absolute-prefix and solib-search-path
5537 For SunOS and SVR4 shared libraries, you may now set the prefix for
5538 loading absolute shared library symbol files, and the search path for
5539 locating non-absolute shared library symbol files.
5541 * Live range splitting
5543 GDB can now effectively debug code for which GCC has performed live
5544 range splitting as part of its optimization. See gdb/doc/LRS for
5545 more details on the expected format of the stabs information.
5549 GDB's support for the GNU Hurd, including thread debugging, has been
5550 updated to work with current versions of the Hurd.
5554 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5555 instruction set. ARM GDB automatically detects when Thumb
5556 instructions are in use, and adjusts disassembly and backtracing
5561 GDB's MIPS target configurations now handle the MIP16 16-bit
5566 GDB now includes support for overlays; if an executable has been
5567 linked such that multiple sections are based at the same address, GDB
5568 will decide which section to use for symbolic info. You can choose to
5569 control the decision manually, using overlay commands, or implement
5570 additional target-side support and use "overlay load-target" to bring
5571 in the overlay mapping. Do "help overlay" for more detail.
5575 The command "info symbol <address>" displays information about
5576 the symbol at the specified address.
5580 The standard remote protocol now includes an extension that allows
5581 asynchronous collection and display of trace data. This requires
5582 extensive support in the target-side debugging stub. Tracing mode
5583 includes a new interaction mode in GDB and new commands: see the
5584 file tracepoint.c for more details.
5588 Configurations for embedded MIPS now include a simulator contributed
5589 by Cygnus Solutions. The simulator supports the instruction sets
5590 of most MIPS variants.
5594 Sparc configurations may now include the ERC32 simulator contributed
5595 by the European Space Agency. The simulator is not built into
5596 Sparc targets by default; configure with --enable-sim to include it.
5600 For target configurations that may include multiple variants of a
5601 basic architecture (such as MIPS and SH), you may now set the
5602 architecture explicitly. "set arch" sets, "info arch" lists
5603 the possible architectures.
5605 *** Changes in GDB-4.16:
5607 * New native configurations
5609 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5610 M68K NetBSD m68k-*-netbsd*
5611 PowerPC AIX 4.x powerpc-*-aix*
5612 PowerPC MacOS powerpc-*-macos*
5613 PowerPC Windows NT powerpcle-*-cygwin32
5614 RS/6000 AIX 4.x rs6000-*-aix4*
5618 ARM with RDP protocol arm-*-*
5619 I960 with MON960 i960-*-coff
5620 MIPS VxWorks mips*-*-vxworks*
5621 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5622 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5624 Matra Sparclet sparclet-*-*
5628 The powerpc-eabi configuration now includes the PSIM simulator,
5629 contributed by Andrew Cagney, with assistance from Mike Meissner.
5630 PSIM is a very elaborate model of the PowerPC, including not only
5631 basic instruction set execution, but also details of execution unit
5632 performance and I/O hardware. See sim/ppc/README for more details.
5636 GDB now works with Solaris 2.5.
5638 * Windows 95/NT native
5640 GDB will now work as a native debugger on Windows 95 and Windows NT.
5641 To build it from source, you must use the "gnu-win32" environment,
5642 which uses a DLL to emulate enough of Unix to run the GNU tools.
5643 Further information, binaries, and sources are available at
5644 ftp.cygnus.com, under pub/gnu-win32.
5646 * dont-repeat command
5648 If a user-defined command includes the command `dont-repeat', then the
5649 command will not be repeated if the user just types return. This is
5650 useful if the command is time-consuming to run, so that accidental
5651 extra keystrokes don't run the same command many times.
5653 * Send break instead of ^C
5655 The standard remote protocol now includes an option to send a break
5656 rather than a ^C to the target in order to interrupt it. By default,
5657 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5659 * Remote protocol timeout
5661 The standard remote protocol includes a new variable `remotetimeout'
5662 that allows you to set the number of seconds before GDB gives up trying
5663 to read from the target. The default value is 2.
5665 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5667 By default GDB will automatically keep track of objects as they are
5668 loaded and unloaded by the dynamic linker. By using the command `set
5669 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5670 when shared library events occur, thus allowing you to set breakpoints
5671 in shared libraries which are explicitly loaded by the inferior.
5673 Note this feature does not work on hpux8. On hpux9 you must link
5674 /usr/lib/end.o into your program. This feature should work
5675 automatically on hpux10.
5677 * Irix 5.x hardware watchpoint support
5679 Irix 5 configurations now support the use of hardware watchpoints.
5681 * Mips protocol "SYN garbage limit"
5683 When debugging a Mips target using the `target mips' protocol, you
5684 may set the number of characters that GDB will ignore by setting
5685 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5686 every character. The default value is 1050.
5688 * Recording and replaying remote debug sessions
5690 If you set `remotelogfile' to the name of a file, gdb will write to it
5691 a recording of a remote debug session. This recording may then be
5692 replayed back to gdb using "gdbreplay". See gdbserver/README for
5693 details. This is useful when you have a problem with GDB while doing
5694 remote debugging; you can make a recording of the session and send it
5695 to someone else, who can then recreate the problem.
5697 * Speedups for remote debugging
5699 GDB includes speedups for downloading and stepping MIPS systems using
5700 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5701 and more efficient S-record downloading.
5703 * Memory use reductions and statistics collection
5705 GDB now uses less memory and reports statistics about memory usage.
5706 Try the `maint print statistics' command, for example.
5708 *** Changes in GDB-4.15:
5710 * Psymtabs for XCOFF
5712 The symbol reader for AIX GDB now uses partial symbol tables. This
5713 can greatly improve startup time, especially for large executables.
5715 * Remote targets use caching
5717 Remote targets now use a data cache to speed up communication with the
5718 remote side. The data cache could lead to incorrect results because
5719 it doesn't know about volatile variables, thus making it impossible to
5720 debug targets which use memory mapped I/O devices. `set remotecache
5721 off' turns the the data cache off.
5723 * Remote targets may have threads
5725 The standard remote protocol now includes support for multiple threads
5726 in the target system, using new protocol commands 'H' and 'T'. See
5727 gdb/remote.c for details.
5731 If GDB is configured with `--enable-netrom', then it will include
5732 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5733 acts as though it is a bank of ROM on the target board, but you can
5734 write into it over the network. GDB's support consists only of
5735 support for fast loading into the emulated ROM; to debug, you must use
5736 another protocol, such as standard remote protocol. The usual
5737 sequence is something like
5739 target nrom <netrom-hostname>
5741 target remote <netrom-hostname>:1235
5745 GDB now includes support for the Apple Macintosh, as a host only. It
5746 may be run as either an MPW tool or as a standalone application, and
5747 it can debug through the serial port. All the usual GDB commands are
5748 available, but to the target command, you must supply "serial" as the
5749 device type instead of "/dev/ttyXX". See mpw-README in the main
5750 directory for more information on how to build. The MPW configuration
5751 scripts */mpw-config.in support only a few targets, and only the
5752 mips-idt-ecoff target has been tested.
5756 GDB configuration now uses autoconf. This is not user-visible,
5757 but does simplify configuration and building.
5761 GDB now supports hpux10.
5763 *** Changes in GDB-4.14:
5765 * New native configurations
5767 x86 FreeBSD i[345]86-*-freebsd
5768 x86 NetBSD i[345]86-*-netbsd
5769 NS32k NetBSD ns32k-*-netbsd
5770 Sparc NetBSD sparc-*-netbsd
5774 A29K VxWorks a29k-*-vxworks
5775 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5776 CPU32 EST-300 emulator m68*-*-est*
5777 PowerPC ELF powerpc-*-elf
5780 * Alpha OSF/1 support for procfs
5782 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5783 possible to attach to running processes. As the mounting of the /proc
5784 filesystem is optional on the Alpha, GDB automatically determines
5785 the availability of /proc during startup. This can lead to problems
5786 if /proc is unmounted after GDB has been started.
5788 * Arguments to user-defined commands
5790 User commands may accept up to 10 arguments separated by whitespace.
5791 Arguments are accessed within the user command via $arg0..$arg9. A
5794 print $arg0 + $arg1 + $arg2
5796 To execute the command use:
5799 Defines the command "adder" which prints the sum of its three arguments.
5800 Note the arguments are text substitutions, so they may reference variables,
5801 use complex expressions, or even perform inferior function calls.
5803 * New `if' and `while' commands
5805 This makes it possible to write more sophisticated user-defined
5806 commands. Both commands take a single argument, which is the
5807 expression to evaluate, and must be followed by the commands to
5808 execute, one per line, if the expression is nonzero, the list being
5809 terminated by the word `end'. The `if' command list may include an
5810 `else' word, which causes the following commands to be executed only
5811 if the expression is zero.
5813 * Fortran source language mode
5815 GDB now includes partial support for Fortran 77. It will recognize
5816 Fortran programs and can evaluate a subset of Fortran expressions, but
5817 variables and functions may not be handled correctly. GDB will work
5818 with G77, but does not yet know much about symbols emitted by other
5821 * Better HPUX support
5823 Most debugging facilities now work on dynamic executables for HPPAs
5824 running hpux9 or later. You can attach to running dynamically linked
5825 processes, but by default the dynamic libraries will be read-only, so
5826 for instance you won't be able to put breakpoints in them. To change
5827 that behavior do the following before running the program:
5833 This will cause the libraries to be mapped private and read-write.
5834 To revert to the normal behavior, do this:
5840 You cannot set breakpoints or examine data in the library until after
5841 the library is loaded if the function/data symbols do not have
5844 GDB can now also read debug symbols produced by the HP C compiler on
5845 HPPAs (sorry, no C++, Fortran or 68k support).
5847 * Target byte order now dynamically selectable
5849 You can choose which byte order to use with a target system, via the
5850 commands "set endian big" and "set endian little", and you can see the
5851 current setting by using "show endian". You can also give the command
5852 "set endian auto", in which case GDB will use the byte order
5853 associated with the executable. Currently, only embedded MIPS
5854 configurations support dynamic selection of target byte order.
5856 * New DOS host serial code
5858 This version uses DPMI interrupts to handle buffered I/O, so you
5859 no longer need to run asynctsr when debugging boards connected to
5862 *** Changes in GDB-4.13:
5864 * New "complete" command
5866 This lists all the possible completions for the rest of the line, if it
5867 were to be given as a command itself. This is intended for use by emacs.
5869 * Trailing space optional in prompt
5871 "set prompt" no longer adds a space for you after the prompt you set. This
5872 allows you to set a prompt which ends in a space or one that does not.
5874 * Breakpoint hit counts
5876 "info break" now displays a count of the number of times the breakpoint
5877 has been hit. This is especially useful in conjunction with "ignore"; you
5878 can ignore a large number of breakpoint hits, look at the breakpoint info
5879 to see how many times the breakpoint was hit, then run again, ignoring one
5880 less than that number, and this will get you quickly to the last hit of
5883 * Ability to stop printing at NULL character
5885 "set print null-stop" will cause GDB to stop printing the characters of
5886 an array when the first NULL is encountered. This is useful when large
5887 arrays actually contain only short strings.
5889 * Shared library breakpoints
5891 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5892 breakpoints in shared libraries before the executable is run.
5894 * Hardware watchpoints
5896 There is a new hardware breakpoint for the watch command for sparclite
5897 targets. See gdb/sparclite/hw_breakpoint.note.
5899 Hardware watchpoints are also now supported under GNU/Linux.
5903 Annotations have been added. These are for use with graphical interfaces,
5904 and are still experimental. Currently only gdba.el uses these.
5906 * Improved Irix 5 support
5908 GDB now works properly with Irix 5.2.
5910 * Improved HPPA support
5912 GDB now works properly with the latest GCC and GAS.
5914 * New native configurations
5916 Sequent PTX4 i[34]86-sequent-ptx4
5917 HPPA running OSF/1 hppa*-*-osf*
5918 Atari TT running SVR4 m68*-*-sysv4*
5919 RS/6000 LynxOS rs6000-*-lynxos*
5923 OS/9000 i[34]86-*-os9k
5924 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5927 * Hitachi SH7000 and E7000-PC ICE support
5929 There is now support for communicating with the Hitachi E7000-PC ICE.
5930 This is available automatically when GDB is configured for the SH.
5934 As usual, a variety of small fixes and improvements, both generic
5935 and configuration-specific. See the ChangeLog for more detail.
5937 *** Changes in GDB-4.12:
5939 * Irix 5 is now supported
5943 GDB-4.12 on the HPPA has a number of changes which make it unable
5944 to debug the output from the currently released versions of GCC and
5945 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5946 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5947 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5950 *** Changes in GDB-4.11:
5952 * User visible changes:
5956 The "set remotedebug" option is now consistent between the mips remote
5957 target, remote targets using the gdb-specific protocol, UDI (AMD's
5958 debug protocol for the 29k) and the 88k bug monitor. It is now an
5959 integer specifying a debug level (normally 0 or 1, but 2 means more
5960 debugging info for the mips target).
5962 * DEC Alpha native support
5964 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5965 debug info, but GDB works fairly well with the DEC compiler and should
5966 work with a future GCC release. See the README file for a few
5967 Alpha-specific notes.
5969 * Preliminary thread implementation
5971 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5973 * LynxOS native and target support for 386
5975 This release has been hosted on LynxOS 2.2, and also can be configured
5976 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5979 * Improvements in C++ mangling/demangling.
5981 This release has much better g++ debugging, specifically in name
5982 mangling/demangling, virtual function calls, print virtual table,
5983 call methods, ...etc.
5985 *** Changes in GDB-4.10:
5987 * User visible changes:
5989 Remote debugging using the GDB-specific (`target remote') protocol now
5990 supports the `load' command. This is only useful if you have some
5991 other way of getting the stub to the target system, and you can put it
5992 somewhere in memory where it won't get clobbered by the download.
5994 Filename completion now works.
5996 When run under emacs mode, the "info line" command now causes the
5997 arrow to point to the line specified. Also, "info line" prints
5998 addresses in symbolic form (as well as hex).
6000 All vxworks based targets now support a user settable option, called
6001 vxworks-timeout. This option represents the number of seconds gdb
6002 should wait for responses to rpc's. You might want to use this if
6003 your vxworks target is, perhaps, a slow software simulator or happens
6004 to be on the far side of a thin network line.
6008 This release contains support for using a DEC alpha as a GDB host for
6009 cross debugging. Native alpha debugging is not supported yet.
6012 *** Changes in GDB-4.9:
6016 This is the first GDB release which is accompanied by a matching testsuite.
6017 The testsuite requires installation of dejagnu, which should be available
6018 via ftp from most sites that carry GNU software.
6022 'Cfront' style demangling has had its name changed to 'ARM' style, to
6023 emphasize that it was written from the specifications in the C++ Annotated
6024 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6025 disclaimers, it still generated too much confusion with users attempting to
6026 use gdb with AT&T cfront.
6030 GDB now uses a standard remote interface to a simulator library.
6031 So far, the library contains simulators for the Zilog Z8001/2, the
6032 Hitachi H8/300, H8/500 and Super-H.
6034 * New targets supported
6036 H8/300 simulator h8300-hitachi-hms or h8300hms
6037 H8/500 simulator h8500-hitachi-hms or h8500hms
6038 SH simulator sh-hitachi-hms or sh
6039 Z8000 simulator z8k-zilog-none or z8ksim
6040 IDT MIPS board over serial line mips-idt-ecoff
6042 Cross-debugging to GO32 targets is supported. It requires a custom
6043 version of the i386-stub.c module which is integrated with the
6044 GO32 memory extender.
6046 * New remote protocols
6048 MIPS remote debugging protocol.
6050 * New source languages supported
6052 This version includes preliminary support for Chill, a Pascal like language
6053 used by telecommunications companies. Chill support is also being integrated
6054 into the GNU compiler, but we don't know when it will be publically available.
6057 *** Changes in GDB-4.8:
6059 * HP Precision Architecture supported
6061 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6062 version of this support was available as a set of patches from the
6063 University of Utah. GDB does not support debugging of programs
6064 compiled with the HP compiler, because HP will not document their file
6065 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6066 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6068 Many problems in the preliminary version have been fixed.
6070 * Faster and better demangling
6072 We have improved template demangling and fixed numerous bugs in the GNU style
6073 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6074 character types (wchar_t) are now supported. Demangling of each symbol is now
6075 only done once, and is cached when the symbol table for a file is read in.
6076 This results in a small increase in memory usage for C programs, a moderate
6077 increase in memory usage for C++ programs, and a fantastic speedup in
6080 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6081 from the specifications in the Annotated Reference Manual, which AT&T's
6082 compiler does not actually implement.
6084 * G++ multiple inheritance compiler problem
6086 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6087 inheritance lattices was reworked to properly discover ambiguities. We
6088 recently found an example which causes this new algorithm to fail in a
6089 very subtle way, producing bad debug information for those classes.
6090 The file 'gcc.patch' (in this directory) can be applied to gcc to
6091 circumvent the problem. A future GCC release will contain a complete
6094 The previous G++ debug info problem (mentioned below for the gdb-4.7
6095 release) is fixed in gcc version 2.3.2.
6097 * Improved configure script
6099 The `configure' script will now attempt to guess your system type if
6100 you don't supply a host system type. The old scheme of supplying a
6101 host system triplet is preferable over using this. All the magic is
6102 done in the new `config.guess' script. Examine it for details.
6104 We have also brought our configure script much more in line with the FSF's
6105 version. It now supports the --with-xxx options. In particular,
6106 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6107 The resulting GDB will not be able to read arbitrary object file formats --
6108 only the format ``expected'' to be used on the configured target system.
6109 We hope to make this the default in a future release.
6111 * Documentation improvements
6113 There's new internal documentation on how to modify GDB, and how to
6114 produce clean changes to the code. We implore people to read it
6115 before submitting changes.
6117 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6118 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6119 `info' files are also provided. To build `info' files from scratch,
6120 you will need the latest `makeinfo' release, which will be available in
6121 a future texinfo-X.Y release.
6123 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6124 We're not sure exactly which versions have this problem, but it has
6125 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6126 or better. If that isn't possible, there is a patch in
6127 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6128 around this problem.
6132 GDB now supports array constants that can be used in expressions typed in by
6133 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6134 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6137 The new directory `gdb/sparclite' contains a program that demonstrates
6138 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6140 * New native hosts supported
6142 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6143 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6145 * New targets supported
6147 AMD 29k family via UDI a29k-amd-udi or udi29k
6149 * New file formats supported
6151 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6152 HPUX core files, and SCO 3.2v2 core files.
6156 Attaching to processes now works again; thanks for the many bug reports.
6158 We have also stomped on a bunch of core dumps caused by
6159 printf_filtered("%s") problems.
6161 We eliminated a copyright problem on the rpc and ptrace header files
6162 for VxWorks, which was discovered at the last minute during the 4.7
6163 release. You should now be able to build a VxWorks GDB.
6165 You can now interrupt gdb while an attached process is running. This
6166 will cause the attached process to stop, and give control back to GDB.
6168 We fixed problems caused by using too many file descriptors
6169 for reading symbols from object files and libraries. This was
6170 especially a problem for programs that used many (~100) shared
6173 The `step' command now only enters a subroutine if there is line number
6174 information for the subroutine. Otherwise it acts like the `next'
6175 command. Previously, `step' would enter subroutines if there was
6176 any debugging information about the routine. This avoids problems
6177 when using `cc -g1' on MIPS machines.
6179 * Internal improvements
6181 GDB's internal interfaces have been improved to make it easier to support
6182 debugging of multiple languages in the future.
6184 GDB now uses a common structure for symbol information internally.
6185 Minimal symbols (derived from linkage symbols in object files), partial
6186 symbols (from a quick scan of debug information), and full symbols
6187 contain a common subset of information, making it easier to write
6188 shared code that handles any of them.
6190 * New command line options
6192 We now accept --silent as an alias for --quiet.
6196 The memory-mapped-malloc library is now licensed under the GNU Library
6197 General Public License.
6199 *** Changes in GDB-4.7:
6201 * Host/native/target split
6203 GDB has had some major internal surgery to untangle the support for
6204 hosts and remote targets. Now, when you configure GDB for a remote
6205 target, it will no longer load in all of the support for debugging
6206 local programs on the host. When fully completed and tested, this will
6207 ensure that arbitrary host/target combinations are possible.
6209 The primary conceptual shift is to separate the non-portable code in
6210 GDB into three categories. Host specific code is required any time GDB
6211 is compiled on that host, regardless of the target. Target specific
6212 code relates to the peculiarities of the target, but can be compiled on
6213 any host. Native specific code is everything else: it can only be
6214 built when the host and target are the same system. Child process
6215 handling and core file support are two common `native' examples.
6217 GDB's use of /proc for controlling Unix child processes is now cleaner.
6218 It has been split out into a single module under the `target_ops' vector,
6219 plus two native-dependent functions for each system that uses /proc.
6221 * New hosts supported
6223 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6224 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6225 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6227 * New targets supported
6229 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6230 68030 and CPU32 m68030-*-*, m68332-*-*
6232 * New native hosts supported
6234 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6235 (386bsd is not well tested yet)
6236 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6238 * New file formats supported
6240 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6241 supports reading of `a.out.adobe' object files, which are an a.out
6242 format extended with minimal information about multiple sections.
6246 `show copying' is the same as the old `info copying'.
6247 `show warranty' is the same as `info warrantee'.
6248 These were renamed for consistency. The old commands continue to work.
6250 `info handle' is a new alias for `info signals'.
6252 You can now define pre-command hooks, which attach arbitrary command
6253 scripts to any command. The commands in the hook will be executed
6254 prior to the user's command. You can also create a hook which will be
6255 executed whenever the program stops. See gdb.texinfo.
6259 We now deal with Cfront style name mangling, and can even extract type
6260 info from mangled symbols. GDB can automatically figure out which
6261 symbol mangling style your C++ compiler uses.
6263 Calling of methods and virtual functions has been improved as well.
6267 The crash that occured when debugging Sun Ansi-C compiled binaries is
6268 fixed. This was due to mishandling of the extra N_SO stabs output
6271 We also finally got Ultrix 4.2 running in house, and fixed core file
6272 support, with help from a dozen people on the net.
6274 John M. Farrell discovered that the reason that single-stepping was so
6275 slow on all of the Mips based platforms (primarily SGI and DEC) was
6276 that we were trying to demangle and lookup a symbol used for internal
6277 purposes on every instruction that was being stepped through. Changing
6278 the name of that symbol so that it couldn't be mistaken for a C++
6279 mangled symbol sped things up a great deal.
6281 Rich Pixley sped up symbol lookups in general by getting much smarter
6282 about when C++ symbol mangling is necessary. This should make symbol
6283 completion (TAB on the command line) much faster. It's not as fast as
6284 we'd like, but it's significantly faster than gdb-4.6.
6288 A new user controllable variable 'call_scratch_address' can
6289 specify the location of a scratch area to be used when GDB
6290 calls a function in the target. This is necessary because the
6291 usual method of putting the scratch area on the stack does not work
6292 in systems that have separate instruction and data spaces.
6294 We integrated changes to support the 29k UDI (Universal Debugger
6295 Interface), but discovered at the last minute that we didn't have all
6296 of the appropriate copyright paperwork. We are working with AMD to
6297 resolve this, and hope to have it available soon.
6301 We have sped up the remote serial line protocol, especially for targets
6302 with lots of registers. It now supports a new `expedited status' ('T')
6303 message which can be used in place of the existing 'S' status message.
6304 This allows the remote stub to send only the registers that GDB
6305 needs to make a quick decision about single-stepping or conditional
6306 breakpoints, eliminating the need to fetch the entire register set for
6307 each instruction being stepped through.
6309 The GDB remote serial protocol now implements a write-through cache for
6310 registers, only re-reading the registers if the target has run.
6312 There is also a new remote serial stub for SPARC processors. You can
6313 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6314 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6315 processor with a serial port.
6319 Configure.in files have become much easier to read and modify. A new
6320 `table driven' format makes it more obvious what configurations are
6321 supported, and what files each one uses.
6325 There is a new opcodes library which will eventually contain all of the
6326 disassembly routines and opcode tables. At present, it only contains
6327 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6328 disassembler (binutils/objdump) to share these routines.
6330 The libiberty library is now copylefted under the GNU Library General
6331 Public License. This allows more liberal use, and was done so libg++
6332 can use it. This makes no difference to GDB, since the Library License
6333 grants all the rights from the General Public License.
6337 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6338 reference to the stabs symbol info used by the debugger. It is (as far
6339 as we know) the only published document on this fascinating topic. We
6340 encourage you to read it, compare it to the stabs information on your
6341 system, and send improvements on the document in general (to
6342 bug-gdb@prep.ai.mit.edu).
6344 And, of course, many bugs have been fixed.
6347 *** Changes in GDB-4.6:
6349 * Better support for C++ function names
6351 GDB now accepts as input the "demangled form" of C++ overloaded function
6352 names and member function names, and can do command completion on such names
6353 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6354 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6355 Make use of command completion, it is your friend.
6357 GDB also now accepts a variety of C++ mangled symbol formats. They are
6358 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6359 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6360 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6361 for the list of formats.
6363 * G++ symbol mangling problem
6365 Recent versions of gcc have a bug in how they emit debugging information for
6366 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6367 directory) can be applied to gcc to fix the problem. Alternatively, if you
6368 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6369 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6370 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6373 * New 'maintenance' command
6375 All of the commands related to hacking GDB internals have been moved out of
6376 the main command set, and now live behind the 'maintenance' command. This
6377 can also be abbreviated as 'mt'. The following changes were made:
6379 dump-me -> maintenance dump-me
6380 info all-breakpoints -> maintenance info breakpoints
6381 printmsyms -> maintenance print msyms
6382 printobjfiles -> maintenance print objfiles
6383 printpsyms -> maintenance print psymbols
6384 printsyms -> maintenance print symbols
6386 The following commands are new:
6388 maintenance demangle Call internal GDB demangler routine to
6389 demangle a C++ link name and prints the result.
6390 maintenance print type Print a type chain for a given symbol
6392 * Change to .gdbinit file processing
6394 We now read the $HOME/.gdbinit file before processing the argv arguments
6395 (e.g. reading symbol files or core files). This allows global parameters to
6396 be set, which will apply during the symbol reading. The ./.gdbinit is still
6397 read after argv processing.
6399 * New hosts supported
6401 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6403 GNU/Linux support i386-unknown-linux or linux
6405 We are also including code to support the HP/PA running BSD and HPUX. This
6406 is almost guaranteed not to work, as we didn't have time to test or build it
6407 for this release. We are including it so that the more adventurous (or
6408 masochistic) of you can play with it. We also had major problems with the
6409 fact that the compiler that we got from HP doesn't support the -g option.
6412 * New targets supported
6414 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6416 * More smarts about finding #include files
6418 GDB now remembers the compilation directory for all include files, and for
6419 all files from which C is generated (like yacc and lex sources). This
6420 greatly improves GDB's ability to find yacc/lex sources, and include files,
6421 especially if you are debugging your program from a directory different from
6422 the one that contains your sources.
6424 We also fixed a bug which caused difficulty with listing and setting
6425 breakpoints in include files which contain C code. (In the past, you had to
6426 try twice in order to list an include file that you hadn't looked at before.)
6428 * Interesting infernals change
6430 GDB now deals with arbitrary numbers of sections, where the symbols for each
6431 section must be relocated relative to that section's landing place in the
6432 target's address space. This work was needed to support ELF with embedded
6433 stabs used by Solaris-2.0.
6435 * Bug fixes (of course!)
6437 There have been loads of fixes for the following things:
6438 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6439 i960, stabs, DOS(GO32), procfs, etc...
6441 See the ChangeLog for details.
6443 *** Changes in GDB-4.5:
6445 * New machines supported (host and target)
6447 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6449 SGI Irix-4.x mips-sgi-irix4 or iris4
6451 * New malloc package
6453 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6454 Mmalloc is capable of handling mutiple heaps of memory. It is also
6455 capable of saving a heap to a file, and then mapping it back in later.
6456 This can be used to greatly speedup the startup of GDB by using a
6457 pre-parsed symbol table which lives in a mmalloc managed heap. For
6458 more details, please read mmalloc/mmalloc.texi.
6462 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6463 'help info proc' for details.
6465 * MIPS ecoff symbol table format
6467 The code that reads MIPS symbol table format is now supported on all hosts.
6468 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6471 * File name changes for MS-DOS
6473 Many files in the config directories have been renamed to make it easier to
6474 support GDB on MS-DOSe systems (which have very restrictive file name
6475 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6476 environment) is close to working but has some remaining problems. Note
6477 that debugging of DOS programs is not supported, due to limitations
6478 in the ``operating system'', but it can be used to host cross-debugging.
6480 * Cross byte order fixes
6482 Many fixes have been made to support cross debugging of Sparc and MIPS
6483 targets from hosts whose byte order differs.
6485 * New -mapped and -readnow options
6487 If memory-mapped files are available on your system through the 'mmap'
6488 system call, you can use the -mapped option on the `file' or
6489 `symbol-file' commands to cause GDB to write the symbols from your
6490 program into a reusable file. If the program you are debugging is
6491 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6492 Future GDB debugging sessions will notice the presence of this file,
6493 and will quickly map in symbol information from it, rather than reading
6494 the symbol table from the executable program. Using the '-mapped'
6495 option in a GDB `file' or `symbol-file' command has the same effect as
6496 starting GDB with the '-mapped' command-line option.
6498 You can cause GDB to read the entire symbol table immediately by using
6499 the '-readnow' option with any of the commands that load symbol table
6500 information (or on the GDB command line). This makes the command
6501 slower, but makes future operations faster.
6503 The -mapped and -readnow options are typically combined in order to
6504 build a `fred.syms' file that contains complete symbol information.
6505 A simple GDB invocation to do nothing but build a `.syms' file for future
6508 gdb -batch -nx -mapped -readnow programname
6510 The `.syms' file is specific to the host machine on which GDB is run.
6511 It holds an exact image of GDB's internal symbol table. It cannot be
6512 shared across multiple host platforms.
6514 * longjmp() handling
6516 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6517 siglongjmp() without losing control. This feature has not yet been ported to
6518 all systems. It currently works on many 386 platforms, all MIPS-based
6519 platforms (SGI, DECstation, etc), and Sun3/4.
6523 Preliminary work has been put in to support the new Solaris OS from Sun. At
6524 this time, it can control and debug processes, but it is not capable of
6529 As always, many many bug fixes. The major areas were with g++, and mipsread.
6530 People using the MIPS-based platforms should experience fewer mysterious
6531 crashes and trashed symbol tables.
6533 *** Changes in GDB-4.4:
6535 * New machines supported (host and target)
6537 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6539 BSD Reno on Vax vax-dec-bsd
6540 Ultrix on Vax vax-dec-ultrix
6542 * New machines supported (target)
6544 AMD 29000 embedded, using EBMON a29k-none-none
6548 GDB continues to improve its handling of C++. `References' work better.
6549 The demangler has also been improved, and now deals with symbols mangled as
6550 per the Annotated C++ Reference Guide.
6552 GDB also now handles `stabs' symbol information embedded in MIPS
6553 `ecoff' symbol tables. Since the ecoff format was not easily
6554 extensible to handle new languages such as C++, this appeared to be a
6555 good way to put C++ debugging info into MIPS binaries. This option
6556 will be supported in the GNU C compiler, version 2, when it is
6559 * New features for SVR4
6561 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6562 shared libraries. Debugging dynamically linked programs should present
6563 only minor differences from debugging statically linked programs.
6565 The `info proc' command will print out information about any process
6566 on an SVR4 system (including the one you are debugging). At the moment,
6567 it prints the address mappings of the process.
6569 If you bring up GDB on another SVR4 system, please send mail to
6570 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6572 * Better dynamic linking support in SunOS
6574 Reading symbols from shared libraries which contain debugging symbols
6575 now works properly. However, there remain issues such as automatic
6576 skipping of `transfer vector' code during function calls, which
6577 make it harder to debug code in a shared library, than to debug the
6578 same code linked statically.
6582 GDB is now using the latest `getopt' routines from the FSF. This
6583 version accepts the -- prefix for options with long names. GDB will
6584 continue to accept the old forms (-option and +option) as well.
6585 Various single letter abbreviations for options have been explicity
6586 added to the option table so that they won't get overshadowed in the
6587 future by other options that begin with the same letter.
6591 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6592 Many assorted bugs have been handled. Many more remain to be handled.
6593 See the various ChangeLog files (primarily in gdb and bfd) for details.
6596 *** Changes in GDB-4.3:
6598 * New machines supported (host and target)
6600 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6601 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6602 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6604 * Almost SCO Unix support
6606 We had hoped to support:
6607 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6608 (except for core file support), but we discovered very late in the release
6609 that it has problems with process groups that render gdb unusable. Sorry
6610 about that. I encourage people to fix it and post the fixes.
6612 * Preliminary ELF and DWARF support
6614 GDB can read ELF object files on System V Release 4, and can handle
6615 debugging records for C, in DWARF format, in ELF files. This support
6616 is preliminary. If you bring up GDB on another SVR4 system, please
6617 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6622 GDB now uses the latest `readline' library. One user-visible change
6623 is that two tabs will list possible command completions, which previously
6624 required typing M-? (meta-question mark, or ESC ?).
6628 The `stepi' bug that many of you noticed has been squashed.
6629 Many bugs in C++ have been handled. Many more remain to be handled.
6630 See the various ChangeLog files (primarily in gdb and bfd) for details.
6632 * State of the MIPS world (in case you wondered):
6634 GDB can understand the symbol tables emitted by the compilers
6635 supplied by most vendors of MIPS-based machines, including DEC. These
6636 symbol tables are in a format that essentially nobody else uses.
6638 Some versions of gcc come with an assembler post-processor called
6639 mips-tfile. This program is required if you want to do source-level
6640 debugging of gcc-compiled programs. I believe FSF does not ship
6641 mips-tfile with gcc version 1, but it will eventually come with gcc
6644 Debugging of g++ output remains a problem. g++ version 1.xx does not
6645 really support it at all. (If you're lucky, you should be able to get
6646 line numbers and stack traces to work, but no parameters or local
6647 variables.) With some work it should be possible to improve the
6650 When gcc version 2 is released, you will have somewhat better luck.
6651 However, even then you will get confusing results for inheritance and
6654 We will eventually provide full debugging of g++ output on
6655 DECstations. This will probably involve some kind of stabs-in-ecoff
6656 encapulation, but the details have not been worked out yet.
6659 *** Changes in GDB-4.2:
6661 * Improved configuration
6663 Only one copy of `configure' exists now, and it is not self-modifying.
6664 Porting BFD is simpler.
6668 The `step' and `next' commands now only stop at the first instruction
6669 of a source line. This prevents the multiple stops that used to occur
6670 in switch statements, for-loops, etc. `Step' continues to stop if a
6671 function that has debugging information is called within the line.
6675 Lots of small bugs fixed. More remain.
6677 * New host supported (not target)
6679 Intel 386 PC clone running Mach i386-none-mach
6682 *** Changes in GDB-4.1:
6684 * Multiple source language support
6686 GDB now has internal scaffolding to handle several source languages.
6687 It determines the type of each source file from its filename extension,
6688 and will switch expression parsing and number formatting to match the
6689 language of the function in the currently selected stack frame.
6690 You can also specifically set the language to be used, with
6691 `set language c' or `set language modula-2'.
6695 GDB now has preliminary support for the GNU Modula-2 compiler,
6696 currently under development at the State University of New York at
6697 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6698 continue through the fall of 1991 and into 1992.
6700 Other Modula-2 compilers are currently not supported, and attempting to
6701 debug programs compiled with them will likely result in an error as the
6702 symbol table is read. Feel free to work on it, though!
6704 There are hooks in GDB for strict type checking and range checking,
6705 in the `Modula-2 philosophy', but they do not currently work.
6709 GDB can now write to executable and core files (e.g. patch
6710 a variable's value). You must turn this switch on, specify
6711 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6712 by assigning a new value to a variable. Modifications take
6715 * Automatic SunOS shared library reading
6717 When you run your program, GDB automatically determines where its
6718 shared libraries (if any) have been loaded, and reads their symbols.
6719 The `share' command is no longer needed. This also works when
6720 examining core files.
6724 You can specify the number of lines that the `list' command shows.
6727 * New machines supported (host and target)
6729 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6730 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6731 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6733 * New hosts supported (not targets)
6735 IBM RT/PC: romp-ibm-aix or rtpc
6737 * New targets supported (not hosts)
6739 AMD 29000 embedded with COFF a29k-none-coff
6740 AMD 29000 embedded with a.out a29k-none-aout
6741 Ultracomputer remote kernel debug a29k-nyu-kern
6743 * New remote interfaces
6749 *** Changes in GDB-4.0:
6753 Wide output is wrapped at good places to make the output more readable.
6755 Gdb now supports cross-debugging from a host machine of one type to a
6756 target machine of another type. Communication with the target system
6757 is over serial lines. The ``target'' command handles connecting to the
6758 remote system; the ``load'' command will download a program into the
6759 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6760 also supports debugging of realtime processes running under VxWorks,
6761 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6762 stub on the target system.
6764 New CPUs supported include the AMD 29000 and Intel 960.
6766 GDB now reads object files and symbol tables via a ``binary file''
6767 library, which allows a single copy of GDB to debug programs of multiple
6768 object file types such as a.out and coff.
6770 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6771 refcard.dvi and refcard.ps are available to format it).
6774 * Control-Variable user interface simplified
6776 All variables that control the operation of the debugger can be set
6777 by the ``set'' command, and displayed by the ``show'' command.
6779 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6780 ``Show prompt'' produces the response:
6781 Gdb's prompt is new-gdb=>.
6783 What follows are the NEW set commands. The command ``help set'' will
6784 print a complete list of old and new set commands. ``help set FOO''
6785 will give a longer description of the variable FOO. ``show'' will show
6786 all of the variable descriptions and their current settings.
6788 confirm on/off: Enables warning questions for operations that are
6789 hard to recover from, e.g. rerunning the program while
6790 it is already running. Default is ON.
6792 editing on/off: Enables EMACS style command line editing
6793 of input. Previous lines can be recalled with
6794 control-P, the current line can be edited with control-B,
6795 you can search for commands with control-R, etc.
6798 history filename NAME: NAME is where the gdb command history
6799 will be stored. The default is .gdb_history,
6800 or the value of the environment variable
6803 history size N: The size, in commands, of the command history. The
6804 default is 256, or the value of the environment variable
6807 history save on/off: If this value is set to ON, the history file will
6808 be saved after exiting gdb. If set to OFF, the
6809 file will not be saved. The default is OFF.
6811 history expansion on/off: If this value is set to ON, then csh-like
6812 history expansion will be performed on
6813 command line input. The default is OFF.
6815 radix N: Sets the default radix for input and output. It can be set
6816 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6817 in the current radix, so "set radix 10" is always a no-op.
6819 height N: This integer value is the number of lines on a page. Default
6820 is 24, the current `stty rows'' setting, or the ``li#''
6821 setting from the termcap entry matching the environment
6824 width N: This integer value is the number of characters on a line.
6825 Default is 80, the current `stty cols'' setting, or the ``co#''
6826 setting from the termcap entry matching the environment
6829 Note: ``set screensize'' is obsolete. Use ``set height'' and
6830 ``set width'' instead.
6832 print address on/off: Print memory addresses in various command displays,
6833 such as stack traces and structure values. Gdb looks
6834 more ``symbolic'' if you turn this off; it looks more
6835 ``machine level'' with it on. Default is ON.
6837 print array on/off: Prettyprint arrays. New convenient format! Default
6840 print demangle on/off: Print C++ symbols in "source" form if on,
6843 print asm-demangle on/off: Same, for assembler level printouts
6846 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6849 * Support for Epoch Environment.
6851 The epoch environment is a version of Emacs v18 with windowing. One
6852 new command, ``inspect'', is identical to ``print'', except that if you
6853 are running in the epoch environment, the value is printed in its own
6857 * Support for Shared Libraries
6859 GDB can now debug programs and core files that use SunOS shared libraries.
6860 Symbols from a shared library cannot be referenced
6861 before the shared library has been linked with the program (this
6862 happens after you type ``run'' and before the function main() is entered).
6863 At any time after this linking (including when examining core files
6864 from dynamically linked programs), gdb reads the symbols from each
6865 shared library when you type the ``sharedlibrary'' command.
6866 It can be abbreviated ``share''.
6868 sharedlibrary REGEXP: Load shared object library symbols for files
6869 matching a unix regular expression. No argument
6870 indicates to load symbols for all shared libraries.
6872 info sharedlibrary: Status of loaded shared libraries.
6877 A watchpoint stops execution of a program whenever the value of an
6878 expression changes. Checking for this slows down execution
6879 tremendously whenever you are in the scope of the expression, but is
6880 quite useful for catching tough ``bit-spreader'' or pointer misuse
6881 problems. Some machines such as the 386 have hardware for doing this
6882 more quickly, and future versions of gdb will use this hardware.
6884 watch EXP: Set a watchpoint (breakpoint) for an expression.
6886 info watchpoints: Information about your watchpoints.
6888 delete N: Deletes watchpoint number N (same as breakpoints).
6889 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6890 enable N: Re-enables watchpoint number N (same as breakpoints).
6893 * C++ multiple inheritance
6895 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6898 * C++ exception handling
6900 Gdb now supports limited C++ exception handling. Besides the existing
6901 ability to breakpoint on an exception handler, gdb can breakpoint on
6902 the raising of an exception (before the stack is peeled back to the
6905 catch FOO: If there is a FOO exception handler in the dynamic scope,
6906 set a breakpoint to catch exceptions which may be raised there.
6907 Multiple exceptions (``catch foo bar baz'') may be caught.
6909 info catch: Lists all exceptions which may be caught in the
6910 current stack frame.
6913 * Minor command changes
6915 The command ``call func (arg, arg, ...)'' now acts like the print
6916 command, except it does not print or save a value if the function's result
6917 is void. This is similar to dbx usage.
6919 The ``up'' and ``down'' commands now always print the frame they end up
6920 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6921 frames without printing.
6923 * New directory command
6925 'dir' now adds directories to the FRONT of the source search path.
6926 The path starts off empty. Source files that contain debug information
6927 about the directory in which they were compiled can be found even
6928 with an empty path; Sun CC and GCC include this information. If GDB can't
6929 find your source file in the current directory, type "dir .".
6931 * Configuring GDB for compilation
6933 For normal use, type ``./configure host''. See README or gdb.texinfo
6936 GDB now handles cross debugging. If you are remotely debugging between
6937 two different machines, type ``./configure host -target=targ''.
6938 Host is the machine where GDB will run; targ is the machine
6939 where the program that you are debugging will run.
projects / external / binutils.git / blob