1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * New "--readnever" command line option instructs GDB to not read each
7 symbol file's symbolic debug information. This makes startup faster
8 but at the expense of not being able to perform symbolic debugging.
9 This option is intended for use cases where symbolic debugging will
10 not be used, e.g., when you only need to dump the debuggee's core.
12 * GDB now uses the GNU MPFR library, if available, to emulate target
13 floating-point arithmetic during expression evaluation when the target
14 uses different floating-point formats than the host. At least version
15 3.1 of GNU MPFR is required.
17 * GDB now supports access to the guarded-storage-control registers and the
18 software-based guarded-storage broadcast control registers on IBM z14.
20 * On Unix systems, GDB now supports transmitting environment variables
21 that are to be set or unset to GDBserver. These variables will
22 affect the environment to be passed to the remote inferior.
24 To inform GDB of environment variables that are to be transmitted to
25 GDBserver, use the "set environment" command. Only user set
26 environment variables are sent to GDBserver.
28 To inform GDB of environment variables that are to be unset before
29 the remote inferior is started by the GDBserver, use the "unset
32 * Completion improvements
34 ** GDB can now complete function parameters in linespecs and
35 explicit locations without quoting. When setting breakpoints,
36 quoting around functions names to help with TAB-completion is
37 generally no longer necessary. For example, this now completes
40 (gdb) b function(in[TAB]
43 Related, GDB is no longer confused with completing functions in
44 C++ anonymous namespaces:
47 (gdb) b (anonymous namespace)::[TAB][TAB]
48 (anonymous namespace)::a_function()
49 (anonymous namespace)::b_function()
51 ** GDB now has much improved linespec and explicit locations TAB
52 completion support, that better understands what you're
53 completing and offers better suggestions. For example, GDB no
54 longer offers data symbols as possible completions when you're
57 ** GDB now TAB-completes label symbol names.
59 ** The "complete" command now mimics TAB completion accurately.
61 * Breakpoints on C++ functions are now set on all scopes by default
63 By default, breakpoints on functions/methods are now interpreted as
64 specifying all functions with the given name ignoring missing
65 leading scopes (namespaces and classes).
67 For example, assuming a C++ program with symbols named:
72 both commands "break func()" and "break B::func()" set a breakpoint
75 You can use the new flag "-qualified" to override this. This makes
76 GDB interpret the specified function name as a complete
77 fully-qualified name instead. For example, using the same C++
78 program, the "break -q B::func" command sets a breakpoint on
81 * Breakpoints on functions marked with C++ ABI tags
83 GDB can now set breakpoints on functions marked with C++ ABI tags
84 (e.g., [abi:cxx11]). See here for a description of ABI tags:
85 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
87 Functions with a C++11 abi tag are demangled/displayed like this:
89 function[abi:cxx11](int)
92 You can now set a breakpoint on such functions simply as if they had
97 Or if you need to disambiguate between tags, like:
99 (gdb) b function[abi:other_tag](int)
101 Tab completion was adjusted accordingly as well.
105 ** New events gdb.new_inferior, gdb.inferior_deleted, and
106 gdb.new_thread are emitted. See the manual for further
107 description of these.
109 ** A new command, "rbreak" has been added to the Python API. This
110 command allows the setting of a large number of breakpoints via a
111 regex pattern in Python. See the manual for further details.
113 * New features in the GDB remote stub, GDBserver
115 ** GDBserver is now able to start inferior processes with a
116 specified initial working directory.
118 The user can set the desired working directory to be used from
119 GDB using the new "set cwd" command.
121 ** New "--selftest" command line option runs some GDBserver self
122 tests. These self tests are disabled in releases.
124 ** On Unix systems, GDBserver now does globbing expansion and variable
125 substitution in inferior command line arguments.
127 This is done by starting inferiors using a shell, like GDB does.
128 See "set startup-with-shell" in the user manual for how to disable
129 this from GDB when using "target extended-remote". When using
130 "target remote", you can disable the startup with shell by using the
131 new "--no-startup-with-shell" GDBserver command line option.
133 ** On Unix systems, GDBserver now supports receiving environment
134 variables that are to be set or unset from GDB. These variables
135 will affect the environment to be passed to the inferior.
137 * When catching an Ada exception raised with a message, GDB now prints
138 the message in the catchpoint hit notification. In GDB/MI mode, that
139 information is provided as an extra field named "exception-message"
140 in the *stopped notification.
142 * Trait objects can now be inspected When debugging Rust code. This
143 requires compiler support which will appear in Rust 1.24.
147 QEnvironmentHexEncoded
148 Inform GDBserver of an environment variable that is to be passed to
149 the inferior when starting it.
152 Inform GDBserver of an environment variable that is to be unset
153 before starting the remote inferior.
156 Inform GDBserver that the environment should be reset (i.e.,
157 user-set environment variables should be unset).
160 Indicates whether the inferior must be started with a shell or not.
163 Tell GDBserver that the inferior to be started should use a specific
166 * The "maintenance print c-tdesc" command now takes an optional
167 argument which is the file name of XML target description.
169 * The "maintenance selftest" command now takes an optional argument to
170 filter the tests to be run.
172 * The "enable", and "disable" commands now accept a range of
173 breakpoint locations, e.g. "enable 1.3-5".
178 Set and show the current working directory for the inferior.
181 Set and show compilation command used for compiling and injecting code
182 with the 'compile' commands.
184 set debug separate-debug-file
185 show debug separate-debug-file
186 Control the display of debug output about separate debug file search.
189 List the registered selftests.
192 Start the debugged program stopping at the first instruction.
194 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
197 * Safer/improved support for debugging with no debug info
199 GDB no longer assumes functions with no debug information return
202 This means that GDB now refuses to call such functions unless you
203 tell it the function's type, by either casting the call to the
204 declared return type, or by casting the function to a function
205 pointer of the right type, and calling that:
207 (gdb) p getenv ("PATH")
208 'getenv' has unknown return type; cast the call to its declared return type
209 (gdb) p (char *) getenv ("PATH")
210 $1 = 0x7fffffffe "/usr/local/bin:/"...
211 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
212 $2 = 0x7fffffffe "/usr/local/bin:/"...
214 Similarly, GDB no longer assumes that global variables with no debug
215 info have type 'int', and refuses to print the variable's value
216 unless you tell it the variable's type:
219 'var' has unknown type; cast it to its declared type
223 * New native configurations
225 FreeBSD/aarch64 aarch64*-*-freebsd*
226 FreeBSD/arm arm*-*-freebsd*
230 FreeBSD/aarch64 aarch64*-*-freebsd*
231 FreeBSD/arm arm*-*-freebsd*
233 * Removed targets and native configurations
235 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
237 *** Changes in GDB 8.0
239 * GDB now supports access to the PKU register on GNU/Linux. The register is
240 added by the Memory Protection Keys for Userspace feature which will be
241 available in future Intel CPUs.
243 * GDB now supports C++11 rvalue references.
247 ** New functions to start, stop and access a running btrace recording.
248 ** Rvalue references are now supported in gdb.Type.
250 * GDB now supports recording and replaying rdrand and rdseed Intel 64
253 * Building GDB and GDBserver now requires a C++11 compiler.
255 For example, GCC 4.8 or later.
257 It is no longer possible to build GDB or GDBserver with a C
258 compiler. The --disable-build-with-cxx configure option has been
261 * Building GDB and GDBserver now requires GNU make >= 3.81.
263 It is no longer supported to build GDB or GDBserver with another
264 implementation of the make program or an earlier version of GNU make.
266 * Native debugging on MS-Windows supports command-line redirection
268 Command-line arguments used for starting programs on MS-Windows can
269 now include redirection symbols supported by native Windows shells,
270 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
271 as "run", "start", and "set args", as well as the corresponding MI
274 * Support for thread names on MS-Windows.
276 GDB now catches and handles the special exception that programs
277 running on MS-Windows use to assign names to threads in the
280 * Support for Java programs compiled with gcj has been removed.
282 * User commands now accept an unlimited number of arguments.
283 Previously, only up to 10 was accepted.
285 * The "eval" command now expands user-defined command arguments.
287 This makes it easier to process a variable number of arguments:
292 eval "print $arg%d", $i
297 * Target descriptions can now describe registers for sparc32 and sparc64.
299 * GDB now supports DWARF version 5 (debug information format).
300 Its .debug_names index is not yet supported.
302 * New native configurations
304 FreeBSD/mips mips*-*-freebsd
308 Synopsys ARC arc*-*-elf32
309 FreeBSD/mips mips*-*-freebsd
311 * Removed targets and native configurations
313 Alpha running FreeBSD alpha*-*-freebsd*
314 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
319 Erases all the flash memory regions reported by the target.
321 maint print arc arc-instruction address
322 Print internal disassembler information about instruction at a given address.
326 set disassembler-options
327 show disassembler-options
328 Controls the passing of target specific information to the disassembler.
329 If it is necessary to specify more than one disassembler option then
330 multiple options can be placed together into a comma separated list.
331 The default value is the empty string. Currently, the only supported
332 targets are ARM, PowerPC and S/390.
337 Erases all the flash memory regions reported by the target. This is
338 equivalent to the CLI command flash-erase.
340 -file-list-shared-libraries
341 List the shared libraries in the program. This is
342 equivalent to the CLI command "info shared".
344 *** Changes in GDB 7.12
346 * GDB and GDBserver now build with a C++ compiler by default.
348 The --enable-build-with-cxx configure option is now enabled by
349 default. One must now explicitly configure with
350 --disable-build-with-cxx in order to build with a C compiler. This
351 option will be removed in a future release.
353 * GDBserver now supports recording btrace without maintaining an active
356 * GDB now supports a negative repeat count in the 'x' command to examine
357 memory backward from the given address. For example:
360 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
361 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
362 (gdb) x/-5i 0x0000000000400580
363 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
364 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
365 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
366 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
367 0x40057b <main(int, char**)+25>:
368 callq 0x400536 <Func1(int, char const*)>
370 * Fortran: Support structures with fields of dynamic types and
371 arrays of dynamic types.
373 * The symbol dumping maintenance commands have new syntax.
374 maint print symbols [-pc address] [--] [filename]
375 maint print symbols [-objfile objfile] [-source source] [--] [filename]
376 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
377 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
378 maint print msymbols [-objfile objfile] [--] [filename]
380 * GDB now supports multibit bitfields and enums in target register
383 * New Python-based convenience function $_as_string(val), which returns
384 the textual representation of a value. This function is especially
385 useful to obtain the text label of an enum value.
387 * Intel MPX bound violation handling.
389 Segmentation faults caused by a Intel MPX boundary violation
390 now display the kind of violation (upper or lower), the memory
391 address accessed and the memory bounds, along with the usual
392 signal received and code location.
396 Program received signal SIGSEGV, Segmentation fault
397 Upper bound violation while accessing address 0x7fffffffc3b3
398 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
399 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
401 * Rust language support.
402 GDB now supports debugging programs written in the Rust programming
403 language. See https://www.rust-lang.org/ for more information about
406 * Support for running interpreters on specified input/output devices
408 GDB now supports a new mechanism that allows frontends to provide
409 fully featured GDB console views, as a better alternative to
410 building such views on top of the "-interpreter-exec console"
411 command. See the new "new-ui" command below. With that command,
412 frontends can now start GDB in the traditional command-line mode
413 running in an embedded terminal emulator widget, and create a
414 separate MI interpreter running on a specified i/o device. In this
415 way, GDB handles line editing, history, tab completion, etc. in the
416 console all by itself, and the GUI uses the separate MI interpreter
417 for its own control and synchronization, invisible to the command
420 * The "catch syscall" command catches groups of related syscalls.
422 The "catch syscall" command now supports catching a group of related
423 syscalls using the 'group:' or 'g:' prefix.
428 skip -gfile file-glob-pattern
429 skip -function function
430 skip -rfunction regular-expression
431 A generalized form of the skip command, with new support for
432 glob-style file names and regular expressions for function names.
433 Additionally, a file spec and a function spec may now be combined.
435 maint info line-table REGEXP
436 Display the contents of GDB's internal line table data struture.
439 Run any GDB unit tests that were compiled in.
442 Start a new user interface instance running INTERP as interpreter,
443 using the TTY file for input/output.
447 ** gdb.Breakpoint objects have a new attribute "pending", which
448 indicates whether the breakpoint is pending.
449 ** Three new breakpoint-related events have been added:
450 gdb.breakpoint_created, gdb.breakpoint_modified, and
451 gdb.breakpoint_deleted.
454 Signal ("set") the given MS-Windows event object. This is used in
455 conjunction with the Windows JIT debugging (AeDebug) support, where
456 the OS suspends a crashing process until a debugger can attach to
457 it. Resuming the crashing process, in order to debug it, is done by
460 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
461 was added in GDBserver, including JIT compiling fast tracepoint's
462 conditional expression bytecode into native code.
464 * Support for various remote target protocols and ROM monitors has
467 target m32rsdi Remote M32R debugging over SDI
468 target mips MIPS remote debugging protocol
469 target pmon PMON ROM monitor
470 target ddb NEC's DDB variant of PMON for Vr4300
471 target rockhopper NEC RockHopper variant of PMON
472 target lsi LSI variant of PMO
474 * Support for tracepoints and fast tracepoints on powerpc-linux,
475 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
476 including JIT compiling fast tracepoint's conditional expression
477 bytecode into native code.
479 * MI async record =record-started now includes the method and format used for
480 recording. For example:
482 =record-started,thread-group="i1",method="btrace",format="bts"
484 * MI async record =thread-selected now includes the frame field. For example:
486 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
490 Andes NDS32 nds32*-*-elf
492 *** Changes in GDB 7.11
494 * GDB now supports debugging kernel-based threads on FreeBSD.
496 * Per-inferior thread numbers
498 Thread numbers are now per inferior instead of global. If you're
499 debugging multiple inferiors, GDB displays thread IDs using a
500 qualified INF_NUM.THR_NUM form. For example:
504 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
505 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
506 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
507 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
509 As consequence, thread numbers as visible in the $_thread
510 convenience variable and in Python's InferiorThread.num attribute
511 are no longer unique between inferiors.
513 GDB now maintains a second thread ID per thread, referred to as the
514 global thread ID, which is the new equivalent of thread numbers in
515 previous releases. See also $_gthread below.
517 For backwards compatibility, MI's thread IDs always refer to global
520 * Commands that accept thread IDs now accept the qualified
521 INF_NUM.THR_NUM form as well. For example:
524 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
527 * In commands that accept a list of thread IDs, you can now refer to
528 all threads of an inferior using a star wildcard. GDB accepts
529 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
530 refer to all threads of the current inferior. For example, "info
533 * You can use "info threads -gid" to display the global thread ID of
536 * The new convenience variable $_gthread holds the global number of
539 * The new convenience variable $_inferior holds the number of the
542 * GDB now displays the ID and name of the thread that hit a breakpoint
543 or received a signal, if your program is multi-threaded. For
546 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
547 Thread 1 "main" received signal SIGINT, Interrupt.
549 * Record btrace now supports non-stop mode.
551 * Support for tracepoints on aarch64-linux was added in GDBserver.
553 * The 'record instruction-history' command now indicates speculative execution
554 when using the Intel Processor Trace recording format.
556 * GDB now allows users to specify explicit locations, bypassing
557 the linespec parser. This feature is also available to GDB/MI
560 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
561 GDB now is able to debug both AArch64 applications and ARM applications
564 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
565 including JIT compiling fast tracepoint's conditional expression bytecode
568 * GDB now supports displaced stepping on AArch64 GNU/Linux.
570 * "info threads", "info inferiors", "info display", "info checkpoints"
571 and "maint info program-spaces" now list the corresponding items in
572 ascending ID order, for consistency with all other "info" commands.
574 * In Ada, the overloads selection menu has been enhanced to display the
575 parameter types and the return types for the matching overloaded subprograms.
579 maint set target-non-stop (on|off|auto)
580 maint show target-non-stop
581 Control whether GDB targets always operate in non-stop mode even if
582 "set non-stop" is "off". The default is "auto", meaning non-stop
583 mode is enabled if supported by the target.
585 maint set bfd-sharing
586 maint show bfd-sharing
587 Control the reuse of bfd objects.
591 Control display of debugging info regarding bfd caching.
595 Control display of debugging info regarding FreeBSD threads.
597 set remote multiprocess-extensions-packet
598 show remote multiprocess-extensions-packet
599 Set/show the use of the remote protocol multiprocess extensions.
601 set remote thread-events
602 show remote thread-events
603 Set/show the use of thread create/exit events.
605 set ada print-signatures on|off
606 show ada print-signatures"
607 Control whether parameter types and return types are displayed in overloads
608 selection menus. It is activaled (@code{on}) by default.
612 Controls the maximum size of memory, in bytes, that GDB will
613 allocate for value contents. Prevents incorrect programs from
614 causing GDB to allocate overly large buffers. Default is 64k.
616 * The "disassemble" command accepts a new modifier: /s.
617 It prints mixed source+disassembly like /m with two differences:
618 - disassembled instructions are now printed in program order, and
619 - and source for all relevant files is now printed.
620 The "/m" option is now considered deprecated: its "source-centric"
621 output hasn't proved useful in practice.
623 * The "record instruction-history" command accepts a new modifier: /s.
624 It behaves exactly like /m and prints mixed source+disassembly.
626 * The "set scheduler-locking" command supports a new mode "replay".
627 It behaves like "off" in record mode and like "on" in replay mode.
629 * Support for various ROM monitors has been removed:
631 target dbug dBUG ROM monitor for Motorola ColdFire
632 target picobug Motorola picobug monitor
633 target dink32 DINK32 ROM monitor for PowerPC
634 target m32r Renesas M32R/D ROM monitor
635 target mon2000 mon2000 ROM monitor
636 target ppcbug PPCBUG ROM monitor for PowerPC
638 * Support for reading/writing memory and extracting values on architectures
639 whose memory is addressable in units of any integral multiple of 8 bits.
644 Indicates that an exec system call was executed.
646 exec-events feature in qSupported
647 The qSupported packet allows GDB to request support for exec
648 events using the new 'gdbfeature' exec-event, and the qSupported
649 response can contain the corresponding 'stubfeature'. Set and
650 show commands can be used to display whether these features are enabled.
653 Equivalent to interrupting with the ^C character, but works in
656 thread created stop reason (T05 create:...)
657 Indicates that the thread was just created and is stopped at entry.
659 thread exit stop reply (w exitcode;tid)
660 Indicates that the thread has terminated.
663 Enables/disables thread create and exit event reporting. For
664 example, this is used in non-stop mode when GDB stops a set of
665 threads and synchronously waits for the their corresponding stop
666 replies. Without exit events, if one of the threads exits, GDB
667 would hang forever not knowing that it should no longer expect a
668 stop for that same thread.
671 Indicates that there are no resumed threads left in the target (all
672 threads are stopped). The remote stub reports support for this stop
673 reply to GDB's qSupported query.
676 Enables/disables catching syscalls from the inferior process.
677 The remote stub reports support for this packet to GDB's qSupported query.
679 syscall_entry stop reason
680 Indicates that a syscall was just called.
682 syscall_return stop reason
683 Indicates that a syscall just returned.
685 * Extended-remote exec events
687 ** GDB now has support for exec events on extended-remote Linux targets.
688 For such targets with Linux kernels 2.5.46 and later, this enables
689 follow-exec-mode and exec catchpoints.
691 set remote exec-event-feature-packet
692 show remote exec-event-feature-packet
693 Set/show the use of the remote exec event feature.
695 * Thread names in remote protocol
697 The reply to qXfer:threads:read may now include a name attribute for each
700 * Target remote mode fork and exec events
702 ** GDB now has support for fork and exec events on target remote mode
703 Linux targets. For such targets with Linux kernels 2.5.46 and later,
704 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
705 fork and exec catchpoints.
707 * Remote syscall events
709 ** GDB now has support for catch syscall on remote Linux targets,
710 currently enabled on x86/x86_64 architectures.
712 set remote catch-syscall-packet
713 show remote catch-syscall-packet
714 Set/show the use of the remote catch syscall feature.
718 ** The -var-set-format command now accepts the zero-hexadecimal
719 format. It outputs data in hexadecimal format with zero-padding on the
724 ** gdb.InferiorThread objects have a new attribute "global_num",
725 which refers to the thread's global thread ID. The existing
726 "num" attribute now refers to the thread's per-inferior number.
727 See "Per-inferior thread numbers" above.
728 ** gdb.InferiorThread objects have a new attribute "inferior", which
729 is the Inferior object the thread belongs to.
731 *** Changes in GDB 7.10
733 * Support for process record-replay and reverse debugging on aarch64*-linux*
734 targets has been added. GDB now supports recording of A64 instruction set
735 including advance SIMD instructions.
737 * Support for Sun's version of the "stabs" debug file format has been removed.
739 * GDB now honors the content of the file /proc/PID/coredump_filter
740 (PID is the process ID) on GNU/Linux systems. This file can be used
741 to specify the types of memory mappings that will be included in a
742 corefile. For more information, please refer to the manual page of
743 "core(5)". GDB also has a new command: "set use-coredump-filter
744 on|off". It allows to set whether GDB will read the content of the
745 /proc/PID/coredump_filter file when generating a corefile.
747 * The "info os" command on GNU/Linux can now display information on
749 "info os cpus" Listing of all cpus/cores on the system
751 * GDB has two new commands: "set serial parity odd|even|none" and
752 "show serial parity". These allows to set or show parity for the
755 * The "info source" command now displays the producer string if it was
756 present in the debug info. This typically includes the compiler version
757 and may include things like its command line arguments.
759 * The "info dll", an alias of the "info sharedlibrary" command,
760 is now available on all platforms.
762 * Directory names supplied to the "set sysroot" commands may be
763 prefixed with "target:" to tell GDB to access shared libraries from
764 the target system, be it local or remote. This replaces the prefix
765 "remote:". The default sysroot has been changed from "" to
766 "target:". "remote:" is automatically converted to "target:" for
767 backward compatibility.
769 * The system root specified by "set sysroot" will be prepended to the
770 filename of the main executable (if reported to GDB as absolute by
771 the operating system) when starting processes remotely, and when
772 attaching to already-running local or remote processes.
774 * GDB now supports automatic location and retrieval of executable
775 files from remote targets. Remote debugging can now be initiated
776 using only a "target remote" or "target extended-remote" command
777 (no "set sysroot" or "file" commands are required). See "New remote
780 * The "dump" command now supports verilog hex format.
782 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
784 * On GNU/Linux, GDB and gdbserver are now able to access executable
785 and shared library files without a "set sysroot" command when
786 attaching to processes running in different mount namespaces from
787 the debugger. This makes it possible to attach to processes in
788 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
789 See "New remote packets" below.
791 * The "tui reg" command now provides completion for all of the
792 available register groups, including target specific groups.
794 * The HISTSIZE environment variable is no longer read when determining
795 the size of GDB's command history. GDB now instead reads the dedicated
796 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
797 disables truncation of command history. Non-numeric values of GDBHISTSIZE
802 ** Memory ports can now be unbuffered.
806 ** gdb.Objfile objects have a new attribute "username",
807 which is the name of the objfile as specified by the user,
808 without, for example, resolving symlinks.
809 ** You can now write frame unwinders in Python.
810 ** gdb.Type objects have a new method "optimized_out",
811 returning optimized out gdb.Value instance of this type.
812 ** gdb.Value objects have new methods "reference_value" and
813 "const_value" which return a reference to the value and a
814 "const" version of the value respectively.
818 maint print symbol-cache
819 Print the contents of the symbol cache.
821 maint print symbol-cache-statistics
822 Print statistics of symbol cache usage.
824 maint flush-symbol-cache
825 Flush the contents of the symbol cache.
829 Start branch trace recording using Branch Trace Store (BTS) format.
832 Evaluate expression by using the compiler and print result.
836 Explicit commands for enabling and disabling tui mode.
839 set mpx bound on i386 and amd64
840 Support for bound table investigation on Intel MPX enabled applications.
844 Start branch trace recording using Intel Processor Trace format.
847 Print information about branch tracing internals.
849 maint btrace packet-history
850 Print the raw branch tracing data.
852 maint btrace clear-packet-history
853 Discard the stored raw branch tracing data.
856 Discard all branch tracing data. It will be fetched and processed
857 anew by the next "record" command.
862 Renamed from "set debug dwarf2-die".
864 Renamed from "show debug dwarf2-die".
867 Renamed from "set debug dwarf2-read".
868 show debug dwarf-read
869 Renamed from "show debug dwarf2-read".
871 maint set dwarf always-disassemble
872 Renamed from "maint set dwarf2 always-disassemble".
873 maint show dwarf always-disassemble
874 Renamed from "maint show dwarf2 always-disassemble".
876 maint set dwarf max-cache-age
877 Renamed from "maint set dwarf2 max-cache-age".
878 maint show dwarf max-cache-age
879 Renamed from "maint show dwarf2 max-cache-age".
882 show debug dwarf-line
883 Control display of debugging info regarding DWARF line processing.
887 Set the maximum number of candidates to be considered during
888 completion. The default value is 200. This limit allows GDB
889 to avoid generating large completion lists, the computation of
890 which can cause the debugger to become temporarily unresponsive.
892 set history remove-duplicates
893 show history remove-duplicates
894 Control the removal of duplicate history entries.
896 maint set symbol-cache-size
897 maint show symbol-cache-size
898 Control the size of the symbol cache.
900 set|show record btrace bts buffer-size
901 Set and show the size of the ring buffer used for branch tracing in
903 The obtained size may differ from the requested size. Use "info
904 record" to see the obtained buffer size.
906 set debug linux-namespaces
907 show debug linux-namespaces
908 Control display of debugging info regarding Linux namespaces.
910 set|show record btrace pt buffer-size
911 Set and show the size of the ring buffer used for branch tracing in
912 Intel Processor Trace format.
913 The obtained size may differ from the requested size. Use "info
914 record" to see the obtained buffer size.
916 maint set|show btrace pt skip-pad
917 Set and show whether PAD packets are skipped when computing the
920 * The command 'thread apply all' can now support new option '-ascending'
921 to call its specified command for all threads in ascending order.
923 * Python/Guile scripting
925 ** GDB now supports auto-loading of Python/Guile scripts contained in the
926 special section named `.debug_gdb_scripts'.
930 qXfer:btrace-conf:read
931 Return the branch trace configuration for the current thread.
933 Qbtrace-conf:bts:size
934 Set the requested ring buffer size for branch tracing in BTS format.
937 Enable Intel Procesor Trace-based branch tracing for the current
938 process. The remote stub reports support for this packet to GDB's
942 Set the requested ring buffer size for branch tracing in Intel Processor
946 Indicates a memory breakpoint instruction was executed, irrespective
947 of whether it was GDB that planted the breakpoint or the breakpoint
948 is hardcoded in the program. This is required for correct non-stop
952 Indicates the target stopped for a hardware breakpoint. This is
953 required for correct non-stop mode operation.
956 Return information about files on the remote system.
959 Return the full absolute name of the file that was executed to
960 create a process running on the remote system.
963 Select the filesystem on which vFile: operations with filename
964 arguments will operate. This is required for GDB to be able to
965 access files on remote targets where the remote stub does not
966 share a common filesystem with the inferior(s).
969 Indicates that a fork system call was executed.
972 Indicates that a vfork system call was executed.
974 vforkdone stop reason
975 Indicates that a vfork child of the specified process has executed
976 an exec or exit, allowing the vfork parent to resume execution.
978 fork-events and vfork-events features in qSupported
979 The qSupported packet allows GDB to request support for fork and
980 vfork events using new 'gdbfeatures' fork-events and vfork-events,
981 and the qSupported response can contain the corresponding
982 'stubfeatures'. Set and show commands can be used to display
983 whether these features are enabled.
985 * Extended-remote fork events
987 ** GDB now has support for fork events on extended-remote Linux
988 targets. For targets with Linux kernels 2.5.60 and later, this
989 enables follow-fork-mode and detach-on-fork for both fork and
990 vfork, as well as fork and vfork catchpoints.
992 * The info record command now shows the recording format and the
993 branch tracing configuration for the current thread when using
994 the btrace record target.
995 For the BTS format, it shows the ring buffer size.
997 * GDB now has support for DTrace USDT (Userland Static Defined
998 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1000 * GDB now supports access to vector registers on S/390 GNU/Linux
1003 * Removed command line options
1005 -xdb HP-UX XDB compatibility mode.
1007 * Removed targets and native configurations
1009 HP/PA running HP-UX hppa*-*-hpux*
1010 Itanium running HP-UX ia64-*-hpux*
1012 * New configure options
1015 This configure option allows the user to build GDB with support for
1016 Intel Processor Trace (default: auto). This requires libipt.
1018 --with-libipt-prefix=PATH
1019 Specify the path to the version of libipt that GDB should use.
1020 $PATH/include should contain the intel-pt.h header and
1021 $PATH/lib should contain the libipt.so library.
1023 *** Changes in GDB 7.9.1
1027 ** Xmethods can now specify a result type.
1029 *** Changes in GDB 7.9
1031 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1035 ** You can now access frame registers from Python scripts.
1036 ** New attribute 'producer' for gdb.Symtab objects.
1037 ** gdb.Objfile objects have a new attribute "progspace",
1038 which is the gdb.Progspace object of the containing program space.
1039 ** gdb.Objfile objects have a new attribute "owner".
1040 ** gdb.Objfile objects have a new attribute "build_id",
1041 which is the build ID generated when the file was built.
1042 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1043 ** A new event "gdb.clear_objfiles" has been added, triggered when
1044 selecting a new file to debug.
1045 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1046 ** New function gdb.lookup_objfile.
1048 New events which are triggered when GDB modifies the state of the
1051 ** gdb.events.inferior_call_pre: Function call is about to be made.
1052 ** gdb.events.inferior_call_post: Function call has just been made.
1053 ** gdb.events.memory_changed: A memory location has been altered.
1054 ** gdb.events.register_changed: A register has been altered.
1056 * New Python-based convenience functions:
1058 ** $_caller_is(name [, number_of_frames])
1059 ** $_caller_matches(regexp [, number_of_frames])
1060 ** $_any_caller_is(name [, number_of_frames])
1061 ** $_any_caller_matches(regexp [, number_of_frames])
1063 * GDB now supports the compilation and injection of source code into
1064 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1065 to compile the source code to object code, and if successful, inject
1066 and execute that code within the current context of the inferior.
1067 Currently the C language is supported. The commands used to
1068 interface with this new feature are:
1070 compile code [-raw|-r] [--] [source code]
1071 compile file [-raw|-r] filename
1075 demangle [-l language] [--] name
1076 Demangle "name" in the specified language, or the current language
1077 if elided. This command is renamed from the "maint demangle" command.
1078 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1079 as "maint demangler-warning".
1081 queue-signal signal-name-or-number
1082 Queue a signal to be delivered to the thread when it is resumed.
1084 add-auto-load-scripts-directory directory
1085 Add entries to the list of directories from which to load auto-loaded
1088 maint print user-registers
1089 List all currently available "user" registers.
1091 compile code [-r|-raw] [--] [source code]
1092 Compile, inject, and execute in the inferior the executable object
1093 code produced by compiling the provided source code.
1095 compile file [-r|-raw] filename
1096 Compile and inject into the inferior the executable object code
1097 produced by compiling the source code stored in the filename
1100 * On resume, GDB now always passes the signal the program had stopped
1101 for to the thread the signal was sent to, even if the user changed
1102 threads before resuming. Previously GDB would often (but not
1103 always) deliver the signal to the thread that happens to be current
1106 * Conversely, the "signal" command now consistently delivers the
1107 requested signal to the current thread. GDB now asks for
1108 confirmation if the program had stopped for a signal and the user
1109 switched threads meanwhile.
1111 * "breakpoint always-inserted" modes "off" and "auto" merged.
1113 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1114 won't remove breakpoints from the target until all threads stop,
1115 even in non-stop mode. The "auto" mode has been removed, and "off"
1116 is now the default mode.
1120 set debug symbol-lookup
1121 show debug symbol-lookup
1122 Control display of debugging info regarding symbol lookup.
1126 ** The -list-thread-groups command outputs an exit-code field for
1127 inferiors that have exited.
1131 MIPS SDE mips*-sde*-elf*
1135 Support for these obsolete configurations has been removed.
1137 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1138 SGI Irix-5.x mips-*-irix5*
1139 SGI Irix-6.x mips-*-irix6*
1140 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1141 VAX running Ultrix vax-*-ultrix*
1143 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1144 and "assf"), have been removed. Use the "sharedlibrary" command, or
1145 its alias "share", instead.
1147 *** Changes in GDB 7.8
1149 * New command line options
1152 This is an alias for the --data-directory option.
1154 * GDB supports printing and modifying of variable length automatic arrays
1155 as specified in ISO C99.
1157 * The ARM simulator now supports instruction level tracing
1158 with or without disassembly.
1162 GDB now has support for scripting using Guile. Whether this is
1163 available is determined at configure time.
1164 Guile version 2.0 or greater is required.
1165 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1167 * New commands (for set/show, see "New options" below)
1171 Invoke CODE by passing it to the Guile interpreter.
1175 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1177 info auto-load guile-scripts [regexp]
1178 Print the list of automatically loaded Guile scripts.
1180 * The source command is now capable of sourcing Guile scripts.
1181 This feature is dependent on the debugger being built with Guile support.
1185 set print symbol-loading (off|brief|full)
1186 show print symbol-loading
1187 Control whether to print informational messages when loading symbol
1188 information for a file. The default is "full", but when debugging
1189 programs with large numbers of shared libraries the amount of output
1190 becomes less useful.
1192 set guile print-stack (none|message|full)
1193 show guile print-stack
1194 Show a stack trace when an error is encountered in a Guile script.
1196 set auto-load guile-scripts (on|off)
1197 show auto-load guile-scripts
1198 Control auto-loading of Guile script files.
1200 maint ada set ignore-descriptive-types (on|off)
1201 maint ada show ignore-descriptive-types
1202 Control whether the debugger should ignore descriptive types in Ada
1203 programs. The default is not to ignore the descriptive types. See
1204 the user manual for more details on descriptive types and the intended
1205 usage of this option.
1207 set auto-connect-native-target
1209 Control whether GDB is allowed to automatically connect to the
1210 native target for the run, attach, etc. commands when not connected
1211 to any target yet. See also "target native" below.
1213 set record btrace replay-memory-access (read-only|read-write)
1214 show record btrace replay-memory-access
1215 Control what memory accesses are allowed during replay.
1217 maint set target-async (on|off)
1218 maint show target-async
1219 This controls whether GDB targets operate in synchronous or
1220 asynchronous mode. Normally the default is asynchronous, if it is
1221 available; but this can be changed to more easily debug problems
1222 occurring only in synchronous mode.
1224 set mi-async (on|off)
1226 Control whether MI asynchronous mode is preferred. This supersedes
1227 "set target-async" of previous GDB versions.
1229 * "set target-async" is deprecated as a CLI option and is now an alias
1230 for "set mi-async" (only puts MI into async mode).
1232 * Background execution commands (e.g., "c&", "s&", etc.) are now
1233 possible ``out of the box'' if the target supports them. Previously
1234 the user would need to explicitly enable the possibility with the
1235 "set target-async on" command.
1237 * New features in the GDB remote stub, GDBserver
1239 ** New option --debug-format=option1[,option2,...] allows one to add
1240 additional text to each output. At present only timestamps
1241 are supported: --debug-format=timestamps.
1242 Timestamps can also be turned on with the
1243 "monitor set debug-format timestamps" command from GDB.
1245 * The 'record instruction-history' command now starts counting instructions
1246 at one. This also affects the instruction ranges reported by the
1247 'record function-call-history' command when given the /i modifier.
1249 * The command 'record function-call-history' supports a new modifier '/c' to
1250 indent the function names based on their call stack depth.
1251 The fields for the '/i' and '/l' modifier have been reordered.
1252 The source line range is now prefixed with 'at'.
1253 The instruction range is now prefixed with 'inst'.
1254 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1255 "record instruction-history" and "list" commands.
1257 * The ranges given as arguments to the 'record function-call-history' and
1258 'record instruction-history' commands are now inclusive.
1260 * The btrace record target now supports the 'record goto' command.
1261 For locations inside the execution trace, the back trace is computed
1262 based on the information stored in the execution trace.
1264 * The btrace record target supports limited reverse execution and replay.
1265 The target does not record data and therefore does not allow reading
1266 memory or registers.
1268 * The "catch syscall" command now works on s390*-linux* targets.
1270 * The "compare-sections" command is no longer specific to target
1271 remote. It now works with all targets.
1273 * All native targets are now consistently called "native".
1274 Consequently, the "target child", "target GNU", "target djgpp",
1275 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1276 commands have been replaced with "target native". The QNX/NTO port
1277 leaves the "procfs" target in place and adds a "native" target for
1278 consistency with other ports. The impact on users should be minimal
1279 as these commands previously either throwed an error, or were
1280 no-ops. The target's name is visible in the output of the following
1281 commands: "help target", "info target", "info files", "maint print
1284 * The "target native" command now connects to the native target. This
1285 can be used to launch native programs even when "set
1286 auto-connect-native-target" is set to off.
1288 * GDB now supports access to Intel MPX registers on GNU/Linux.
1290 * Support for Intel AVX-512 registers on GNU/Linux.
1291 Support displaying and modifying Intel AVX-512 registers
1292 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1294 * New remote packets
1296 qXfer:btrace:read's annex
1297 The qXfer:btrace:read packet supports a new annex 'delta' to read
1298 branch trace incrementally.
1302 ** Valid Python operations on gdb.Value objects representing
1303 structs/classes invoke the corresponding overloaded operators if
1305 ** New `Xmethods' feature in the Python API. Xmethods are
1306 additional methods or replacements for existing methods of a C++
1307 class. This feature is useful for those cases where a method
1308 defined in C++ source code could be inlined or optimized out by
1309 the compiler, making it unavailable to GDB.
1312 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1314 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1315 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1316 its alias "share", instead.
1318 * The commands "set remotebaud" and "show remotebaud" are no longer
1319 supported. Use "set serial baud" and "show serial baud" (respectively)
1324 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1325 target-async". The latter is left as a deprecated alias of the
1326 former for backward compatibility. If the target supports it,
1327 CLI background execution commands are now always possible by
1328 default, independently of whether the frontend stated a
1329 preference for asynchronous execution with "-gdb-set mi-async".
1330 Previously "-gdb-set target-async off" affected both MI execution
1331 commands and CLI execution commands.
1333 *** Changes in GDB 7.7
1335 * Improved support for process record-replay and reverse debugging on
1336 arm*-linux* targets. Support for thumb32 and syscall instruction
1337 recording has been added.
1339 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1341 * GDB now supports Fission DWP file format version 2.
1342 http://gcc.gnu.org/wiki/DebugFission
1344 * New convenience function "$_isvoid", to check whether an expression
1345 is void. A void expression is an expression where the type of the
1346 result is "void". For example, some convenience variables may be
1347 "void" when evaluated (e.g., "$_exitcode" before the execution of
1348 the program being debugged; or an undefined convenience variable).
1349 Another example, when calling a function whose return type is
1352 * The "maintenance print objfiles" command now takes an optional regexp.
1354 * The "catch syscall" command now works on arm*-linux* targets.
1356 * GDB now consistently shows "<not saved>" when printing values of
1357 registers the debug info indicates have not been saved in the frame
1358 and there's nowhere to retrieve them from
1359 (callee-saved/call-clobbered registers):
1364 (gdb) info registers rax
1367 Before, the former would print "<optimized out>", and the latter
1368 "*value not available*".
1370 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1375 ** Frame filters and frame decorators have been added.
1376 ** Temporary breakpoints are now supported.
1377 ** Line tables representation has been added.
1378 ** New attribute 'parent_type' for gdb.Field objects.
1379 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1380 ** New attribute 'name' for gdb.Type objects.
1384 Nios II ELF nios2*-*-elf
1385 Nios II GNU/Linux nios2*-*-linux
1386 Texas Instruments MSP430 msp430*-*-elf
1388 * Removed native configurations
1390 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1391 been removed. ELF variants of these configurations are kept supported.
1393 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1394 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1395 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1396 i[34567]86-*-openbsd3.[0-3]
1397 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1398 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1399 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1403 Like "catch throw", but catches a re-thrown exception.
1404 maint check-psymtabs
1405 Renamed from old "maint check-symtabs".
1407 Perform consistency checks on symtabs.
1408 maint expand-symtabs
1409 Expand symtabs matching an optional regexp.
1412 Display the details of GDB configure-time options.
1414 maint set|show per-command
1415 maint set|show per-command space
1416 maint set|show per-command time
1417 maint set|show per-command symtab
1418 Enable display of per-command gdb resource usage.
1420 remove-symbol-file FILENAME
1421 remove-symbol-file -a ADDRESS
1422 Remove a symbol file added via add-symbol-file. The file to remove
1423 can be identified by its filename or by an address that lies within
1424 the boundaries of this symbol file in memory.
1427 info exceptions REGEXP
1428 Display the list of Ada exceptions defined in the program being
1429 debugged. If provided, only the exceptions whose names match REGEXP
1434 set debug symfile off|on
1436 Control display of debugging info regarding reading symbol files and
1437 symbol tables within those files
1439 set print raw frame-arguments
1440 show print raw frame-arguments
1441 Set/show whether to print frame arguments in raw mode,
1442 disregarding any defined pretty-printers.
1444 set remote trace-status-packet
1445 show remote trace-status-packet
1446 Set/show the use of remote protocol qTStatus packet.
1450 Control display of debugging messages related to Nios II targets.
1454 Control whether target-assisted range stepping is enabled.
1456 set startup-with-shell
1457 show startup-with-shell
1458 Specifies whether Unix child processes are started via a shell or
1463 Use the target memory cache for accesses to the code segment. This
1464 improves performance of remote debugging (particularly disassembly).
1466 * You can now use a literal value 'unlimited' for options that
1467 interpret 0 or -1 as meaning "unlimited". E.g., "set
1468 trace-buffer-size unlimited" is now an alias for "set
1469 trace-buffer-size -1" and "set height unlimited" is now an alias for
1472 * The "set debug symtab-create" debugging option of GDB has been changed to
1473 accept a verbosity level. 0 means "off", 1 provides basic debugging
1474 output, and values of 2 or greater provides more verbose output.
1476 * New command-line options
1478 Display the details of GDB configure-time options.
1480 * The command 'tsave' can now support new option '-ctf' to save trace
1481 buffer in Common Trace Format.
1483 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1486 * GDB now implements the the C++ 'typeid' operator.
1488 * The new convenience variable $_exception holds the exception being
1489 thrown or caught at an exception-related catchpoint.
1491 * The exception-related catchpoints, like "catch throw", now accept a
1492 regular expression which can be used to filter exceptions by type.
1494 * The new convenience variable $_exitsignal is automatically set to
1495 the terminating signal number when the program being debugged dies
1496 due to an uncaught signal.
1500 ** All MI commands now accept an optional "--language" option.
1501 Support for this feature can be verified by using the "-list-features"
1502 command, which should contain "language-option".
1504 ** The new command -info-gdb-mi-command allows the user to determine
1505 whether a GDB/MI command is supported or not.
1507 ** The "^error" result record returned when trying to execute an undefined
1508 GDB/MI command now provides a variable named "code" whose content is the
1509 "undefined-command" error code. Support for this feature can be verified
1510 by using the "-list-features" command, which should contain
1511 "undefined-command-error-code".
1513 ** The -trace-save MI command can optionally save trace buffer in Common
1516 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1518 ** The command -data-list-register-values now accepts an optional
1519 "--skip-unavailable" option. When used, only the available registers
1522 ** The new command -trace-frame-collected dumps collected variables,
1523 computed expressions, tvars, memory and registers in a traceframe.
1525 ** The commands -stack-list-locals, -stack-list-arguments and
1526 -stack-list-variables now accept an option "--skip-unavailable".
1527 When used, only the available locals or arguments are displayed.
1529 ** The -exec-run command now accepts an optional "--start" option.
1530 When used, the command follows the same semantics as the "start"
1531 command, stopping the program's execution at the start of its
1532 main subprogram. Support for this feature can be verified using
1533 the "-list-features" command, which should contain
1534 "exec-run-start-option".
1536 ** The new commands -catch-assert and -catch-exceptions insert
1537 catchpoints stopping the program when Ada exceptions are raised.
1539 ** The new command -info-ada-exceptions provides the equivalent of
1540 the new "info exceptions" command.
1542 * New system-wide configuration scripts
1543 A GDB installation now provides scripts suitable for use as system-wide
1544 configuration scripts for the following systems:
1548 * GDB now supports target-assigned range stepping with remote targets.
1549 This improves the performance of stepping source lines by reducing
1550 the number of control packets from/to GDB. See "New remote packets"
1553 * GDB now understands the element 'tvar' in the XML traceframe info.
1554 It has the id of the collected trace state variables.
1556 * On S/390 targets that provide the transactional-execution feature,
1557 the program interruption transaction diagnostic block (TDB) is now
1558 represented as a number of additional "registers" in GDB.
1560 * New remote packets
1564 The vCont packet supports a new 'r' action, that tells the remote
1565 stub to step through an address range itself, without GDB
1566 involvemement at each single-step.
1568 qXfer:libraries-svr4:read's annex
1569 The previously unused annex of the qXfer:libraries-svr4:read packet
1570 is now used to support passing an argument list. The remote stub
1571 reports support for this argument list to GDB's qSupported query.
1572 The defined arguments are "start" and "prev", used to reduce work
1573 necessary for library list updating, resulting in significant
1576 * New features in the GDB remote stub, GDBserver
1578 ** GDBserver now supports target-assisted range stepping. Currently
1579 enabled on x86/x86_64 GNU/Linux targets.
1581 ** GDBserver now adds element 'tvar' in the XML in the reply to
1582 'qXfer:traceframe-info:read'. It has the id of the collected
1583 trace state variables.
1585 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1588 * New 'z' formatter for printing and examining memory, this displays the
1589 value as hexadecimal zero padded on the left to the size of the type.
1591 * GDB can now use Windows x64 unwinding data.
1593 * The "set remotebaud" command has been replaced by "set serial baud".
1594 Similarly, "show remotebaud" has been replaced by "show serial baud".
1595 The "set remotebaud" and "show remotebaud" commands are still available
1596 to provide backward compatibility with older versions of GDB.
1598 *** Changes in GDB 7.6
1600 * Target record has been renamed to record-full.
1601 Record/replay is now enabled with the "record full" command.
1602 This also affects settings that are associated with full record/replay
1603 that have been moved from "set/show record" to "set/show record full":
1605 set|show record full insn-number-max
1606 set|show record full stop-at-limit
1607 set|show record full memory-query
1609 * A new record target "record-btrace" has been added. The new target
1610 uses hardware support to record the control-flow of a process. It
1611 does not support replaying the execution, but it implements the
1612 below new commands for investigating the recorded execution log.
1613 This new recording method can be enabled using:
1617 The "record-btrace" target is only available on Intel Atom processors
1618 and requires a Linux kernel 2.6.32 or later.
1620 * Two new commands have been added for record/replay to give information
1621 about the recorded execution without having to replay the execution.
1622 The commands are only supported by "record btrace".
1624 record instruction-history prints the execution history at
1625 instruction granularity
1627 record function-call-history prints the execution history at
1628 function granularity
1630 * New native configurations
1632 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1633 FreeBSD/powerpc powerpc*-*-freebsd
1634 x86_64/Cygwin x86_64-*-cygwin*
1635 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1639 ARM AArch64 aarch64*-*-elf
1640 ARM AArch64 GNU/Linux aarch64*-*-linux
1641 Lynx 178 PowerPC powerpc-*-lynx*178
1642 x86_64/Cygwin x86_64-*-cygwin*
1643 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1645 * If the configured location of system.gdbinit file (as given by the
1646 --with-system-gdbinit option at configure time) is in the
1647 data-directory (as specified by --with-gdb-datadir at configure
1648 time) or in one of its subdirectories, then GDB will look for the
1649 system-wide init file in the directory specified by the
1650 --data-directory command-line option.
1652 * New command line options:
1654 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1655 other initialization files, unlike -nx which disables all of them.
1657 * Removed command line options
1659 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1662 * The 'ptype' and 'whatis' commands now accept an argument to control
1665 * 'info proc' now works on some core files.
1669 ** Vectors can be created with gdb.Type.vector.
1671 ** Python's atexit.register now works in GDB.
1673 ** Types can be pretty-printed via a Python API.
1675 ** Python 3 is now supported (in addition to Python 2.4 or later)
1677 ** New class gdb.Architecture exposes GDB's internal representation
1678 of architecture in the Python API.
1680 ** New method Frame.architecture returns the gdb.Architecture object
1681 corresponding to the frame's architecture.
1683 * New Python-based convenience functions:
1685 ** $_memeq(buf1, buf2, length)
1686 ** $_streq(str1, str2)
1688 ** $_regex(str, regex)
1690 * The 'cd' command now defaults to using '~' (the home directory) if not
1693 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1694 default for GCC since November 2000.
1696 * The command 'forward-search' can now be abbreviated as 'fo'.
1698 * The command 'info tracepoints' can now display 'installed on target'
1699 or 'not installed on target' for each non-pending location of tracepoint.
1701 * New configure options
1703 --enable-libmcheck/--disable-libmcheck
1704 By default, development versions are built with -lmcheck on hosts
1705 that support it, in order to help track memory corruption issues.
1706 Release versions, on the other hand, are built without -lmcheck
1707 by default. The --enable-libmcheck/--disable-libmcheck configure
1708 options allow the user to override that default.
1709 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1710 This configure option allows the user to build GDB with
1711 libbabeltrace using which GDB can read Common Trace Format data.
1713 * New commands (for set/show, see "New options" below)
1716 Catch signals. This is similar to "handle", but allows commands and
1717 conditions to be attached.
1720 List the BFDs known to GDB.
1722 python-interactive [command]
1724 Start a Python interactive prompt, or evaluate the optional command
1725 and print the result of expressions.
1728 "py" is a new alias for "python".
1730 enable type-printer [name]...
1731 disable type-printer [name]...
1732 Enable or disable type printers.
1736 ** For the Renesas Super-H architecture, the "regs" command has been removed
1737 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1742 set print type methods (on|off)
1743 show print type methods
1744 Control whether method declarations are displayed by "ptype".
1745 The default is to show them.
1747 set print type typedefs (on|off)
1748 show print type typedefs
1749 Control whether typedef definitions are displayed by "ptype".
1750 The default is to show them.
1752 set filename-display basename|relative|absolute
1753 show filename-display
1754 Control the way in which filenames is displayed.
1755 The default is "relative", which preserves previous behavior.
1757 set trace-buffer-size
1758 show trace-buffer-size
1759 Request target to change the size of trace buffer.
1761 set remote trace-buffer-size-packet auto|on|off
1762 show remote trace-buffer-size-packet
1763 Control the use of the remote protocol `QTBuffer:size' packet.
1767 Control display of debugging messages related to ARM AArch64.
1770 set debug coff-pe-read
1771 show debug coff-pe-read
1772 Control display of debugging messages related to reading of COFF/PE
1777 Control display of debugging messages related to Mach-O symbols
1780 set debug notification
1781 show debug notification
1782 Control display of debugging info for async remote notification.
1786 ** Command parameter changes are now notified using new async record
1787 "=cmd-param-changed".
1788 ** Trace frame changes caused by command "tfind" are now notified using
1789 new async record "=traceframe-changed".
1790 ** The creation, deletion and modification of trace state variables
1791 are now notified using new async records "=tsv-created",
1792 "=tsv-deleted" and "=tsv-modified".
1793 ** The start and stop of process record are now notified using new
1794 async record "=record-started" and "=record-stopped".
1795 ** Memory changes are now notified using new async record
1797 ** The data-disassemble command response will include a "fullname" field
1798 containing the absolute file name when source has been requested.
1799 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1800 command, to allow pattern filling of memory areas.
1801 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1802 library load/unload events.
1803 ** The response to breakpoint commands and breakpoint async records
1804 includes an "installed" field containing a boolean state about each
1805 non-pending tracepoint location is whether installed on target or not.
1806 ** Output of the "-trace-status" command includes a "trace-file" field
1807 containing the name of the trace file being examined. This field is
1808 optional, and only present when examining a trace file.
1809 ** The "fullname" field is now always present along with the "file" field,
1810 even if the file cannot be found by GDB.
1812 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1813 You must have the LZMA library available when configuring GDB for this
1814 feature to be enabled. For more information, see:
1815 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1817 * New remote packets
1820 Set the size of trace buffer. The remote stub reports support for this
1821 packet to gdb's qSupported query.
1824 Enable Branch Trace Store (BTS)-based branch tracing for the current
1825 thread. The remote stub reports support for this packet to gdb's
1829 Disable branch tracing for the current thread. The remote stub reports
1830 support for this packet to gdb's qSupported query.
1833 Read the traced branches for the current thread. The remote stub
1834 reports support for this packet to gdb's qSupported query.
1836 *** Changes in GDB 7.5
1838 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1839 for more x32 ABI info.
1841 * GDB now supports access to MIPS DSP registers on Linux targets.
1843 * GDB now supports debugging microMIPS binaries.
1845 * The "info os" command on GNU/Linux can now display information on
1846 several new classes of objects managed by the operating system:
1847 "info os procgroups" lists process groups
1848 "info os files" lists file descriptors
1849 "info os sockets" lists internet-domain sockets
1850 "info os shm" lists shared-memory regions
1851 "info os semaphores" lists semaphores
1852 "info os msg" lists message queues
1853 "info os modules" lists loaded kernel modules
1855 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1856 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1857 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1858 options and inspect the probe arguments using the new $_probe_arg family
1859 of convenience variables. You can obtain more information about SystemTap
1860 in <http://sourceware.org/systemtap/>.
1862 * GDB now supports reversible debugging on ARM, it allows you to
1863 debug basic ARM and THUMB instructions, and provides
1864 record/replay support.
1866 * The option "symbol-reloading" has been deleted as it is no longer used.
1870 ** GDB commands implemented in Python can now be put in command class
1873 ** The "maint set python print-stack on|off" is now deleted.
1875 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1876 apply "flag enum"-style pretty-printing to any enum.
1878 ** gdb.lookup_symbol can now work when there is no current frame.
1880 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1881 the source at which the symbol was defined.
1883 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1884 method 'value'. The former indicates whether the symbol needs a
1885 frame in order to compute its value, and the latter computes the
1888 ** A new method 'referenced_value' on gdb.Value objects which can
1889 dereference pointer as well as C++ reference values.
1891 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1892 which return the global and static blocks (as gdb.Block objects),
1893 of the underlying symbol table, respectively.
1895 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1896 object associated with a PC value.
1898 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1899 of the address range occupied by code for the current source line.
1901 * Go language support.
1902 GDB now supports debugging programs written in the Go programming
1905 * GDBserver now supports stdio connections.
1906 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1908 * The binary "gdbtui" can no longer be built or installed.
1909 Use "gdb -tui" instead.
1911 * GDB will now print "flag" enums specially. A flag enum is one where
1912 all the enumerator values have no bits in common when pairwise
1913 "and"ed. When printing a value whose type is a flag enum, GDB will
1914 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1915 (gdb) print (enum E) 3
1918 * The filename part of a linespec will now match trailing components
1919 of a source file name. For example, "break gcc/expr.c:1000" will
1920 now set a breakpoint in build/gcc/expr.c, but not
1921 build/libcpp/expr.c.
1923 * The "info proc" and "generate-core-file" commands will now also
1924 work on remote targets connected to GDBserver on Linux.
1926 * The command "info catch" has been removed. It has been disabled
1927 since December 2007.
1929 * The "catch exception" and "catch assert" commands now accept
1930 a condition at the end of the command, much like the "break"
1931 command does. For instance:
1933 (gdb) catch exception Constraint_Error if Barrier = True
1935 Previously, it was possible to add a condition to such catchpoints,
1936 but it had to be done as a second step, after the catchpoint had been
1937 created, using the "condition" command.
1939 * The "info static-tracepoint-marker" command will now also work on
1940 native Linux targets with in-process agent.
1942 * GDB can now set breakpoints on inlined functions.
1944 * The .gdb_index section has been updated to include symbols for
1945 inlined functions. GDB will ignore older .gdb_index sections by
1946 default, which could cause symbol files to be loaded more slowly
1947 until their .gdb_index sections can be recreated. The new command
1948 "set use-deprecated-index-sections on" will cause GDB to use any older
1949 .gdb_index sections it finds. This will restore performance, but the
1950 ability to set breakpoints on inlined functions will be lost in symbol
1951 files with older .gdb_index sections.
1953 The .gdb_index section has also been updated to record more information
1954 about each symbol. This speeds up the "info variables", "info functions"
1955 and "info types" commands when used with programs having the .gdb_index
1956 section, as well as speeding up debugging with shared libraries using
1957 the .gdb_index section.
1959 * Ada support for GDB/MI Variable Objects has been added.
1961 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1966 ** New command -info-os is the MI equivalent of "info os".
1968 ** Output logs ("set logging" and related) now include MI output.
1972 ** "set use-deprecated-index-sections on|off"
1973 "show use-deprecated-index-sections on|off"
1974 Controls the use of deprecated .gdb_index sections.
1976 ** "catch load" and "catch unload" can be used to stop when a shared
1977 library is loaded or unloaded, respectively.
1979 ** "enable count" can be used to auto-disable a breakpoint after
1982 ** "info vtbl" can be used to show the virtual method tables for
1983 C++ and Java objects.
1985 ** "explore" and its sub commands "explore value" and "explore type"
1986 can be used to recursively explore values and types of
1987 expressions. These commands are available only if GDB is
1988 configured with '--with-python'.
1990 ** "info auto-load" shows status of all kinds of auto-loaded files,
1991 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1992 sequences of commands files, "info auto-load python-scripts"
1993 shows status of auto-loading Python script files,
1994 "info auto-load local-gdbinit" shows status of loading init file
1995 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1996 status of inferior specific thread debugging shared library loading.
1998 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1999 and "show auto-load-scripts" commands have been deprecated, use their
2000 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2001 and "show auto-load python-scripts" counterparts instead.
2003 ** "dprintf location,format,args..." creates a dynamic printf, which
2004 is basically a breakpoint that does a printf and immediately
2005 resumes your program's execution, so it is like a printf that you
2006 can insert dynamically at runtime instead of at compiletime.
2008 ** "set print symbol"
2010 Controls whether GDB attempts to display the symbol, if any,
2011 corresponding to addresses it prints. This defaults to "on", but
2012 you can set it to "off" to restore GDB's previous behavior.
2014 * Deprecated commands
2016 ** For the Renesas Super-H architecture, the "regs" command has been
2017 deprecated, and "info all-registers" should be used instead.
2021 Renesas RL78 rl78-*-elf
2022 HP OpenVMS ia64 ia64-hp-openvms*
2024 * GDBserver supports evaluation of breakpoint conditions. When
2025 support is advertised by GDBserver, GDB may be told to send the
2026 breakpoint conditions in bytecode form to GDBserver. GDBserver
2027 will only report the breakpoint trigger to GDB when its condition
2032 set mips compression
2033 show mips compression
2034 Select the compressed ISA encoding used in functions that have no symbol
2035 information available. The encoding can be set to either of:
2038 and is updated automatically from ELF file flags if available.
2040 set breakpoint condition-evaluation
2041 show breakpoint condition-evaluation
2042 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2043 GDBserver ("target"). Default option "auto" chooses the most efficient
2045 This option can improve debugger efficiency depending on the speed of the
2049 Disable auto-loading globally.
2052 Show auto-loading setting of all kinds of auto-loaded files.
2054 set auto-load gdb-scripts on|off
2055 show auto-load gdb-scripts
2056 Control auto-loading of GDB canned sequences of commands files.
2058 set auto-load python-scripts on|off
2059 show auto-load python-scripts
2060 Control auto-loading of Python script files.
2062 set auto-load local-gdbinit on|off
2063 show auto-load local-gdbinit
2064 Control loading of init file (.gdbinit) from current directory.
2066 set auto-load libthread-db on|off
2067 show auto-load libthread-db
2068 Control auto-loading of inferior specific thread debugging shared library.
2070 set auto-load scripts-directory <dir1>[:<dir2>...]
2071 show auto-load scripts-directory
2072 Set a list of directories from which to load auto-loaded scripts.
2073 Automatically loaded Python scripts and GDB scripts are located in one
2074 of the directories listed by this option.
2075 The delimiter (':' above) may differ according to the host platform.
2077 set auto-load safe-path <dir1>[:<dir2>...]
2078 show auto-load safe-path
2079 Set a list of directories from which it is safe to auto-load files.
2080 The delimiter (':' above) may differ according to the host platform.
2082 set debug auto-load on|off
2083 show debug auto-load
2084 Control display of debugging info for auto-loading the files above.
2086 set dprintf-style gdb|call|agent
2088 Control the way in which a dynamic printf is performed; "gdb"
2089 requests a GDB printf command, while "call" causes dprintf to call a
2090 function in the inferior. "agent" requests that the target agent
2091 (such as GDBserver) do the printing.
2093 set dprintf-function <expr>
2094 show dprintf-function
2095 set dprintf-channel <expr>
2096 show dprintf-channel
2097 Set the function and optional first argument to the call when using
2098 the "call" style of dynamic printf.
2100 set disconnected-dprintf on|off
2101 show disconnected-dprintf
2102 Control whether agent-style dynamic printfs continue to be in effect
2103 after GDB disconnects.
2105 * New configure options
2107 --with-auto-load-dir
2108 Configure default value for the 'set auto-load scripts-directory'
2109 setting above. It defaults to '$debugdir:$datadir/auto-load',
2110 $debugdir representing global debugging info directories (available
2111 via 'show debug-file-directory') and $datadir representing GDB's data
2112 directory (available via 'show data-directory').
2114 --with-auto-load-safe-path
2115 Configure default value for the 'set auto-load safe-path' setting
2116 above. It defaults to the --with-auto-load-dir setting.
2118 --without-auto-load-safe-path
2119 Set 'set auto-load safe-path' to '/', effectively disabling this
2122 * New remote packets
2124 z0/z1 conditional breakpoints extension
2126 The z0/z1 breakpoint insertion packets have been extended to carry
2127 a list of conditional expressions over to the remote stub depending on the
2128 condition evaluation mode. The use of this extension can be controlled
2129 via the "set remote conditional-breakpoints-packet" command.
2133 Specify the signals which the remote stub may pass to the debugged
2134 program without GDB involvement.
2136 * New command line options
2138 --init-command=FILE, -ix Like --command, -x but execute it
2139 before loading inferior.
2140 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2141 execute it before loading inferior.
2143 *** Changes in GDB 7.4
2145 * GDB now handles ambiguous linespecs more consistently; the existing
2146 FILE:LINE support has been expanded to other types of linespecs. A
2147 breakpoint will now be set on all matching locations in all
2148 inferiors, and locations will be added or removed according to
2151 * GDB now allows you to skip uninteresting functions and files when
2152 stepping with the "skip function" and "skip file" commands.
2154 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2155 and "show remote hardware-watchpoint-length-limit". These allows to
2156 set or show the maximum length limit (in bytes) of a remote
2157 target hardware watchpoint.
2159 This allows e.g. to use "unlimited" hardware watchpoints with the
2160 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2161 watchpoints are slower than real hardware watchpoints but are
2162 significantly faster than gdb software watchpoints.
2166 ** The register_pretty_printer function in module gdb.printing now takes
2167 an optional `replace' argument. If True, the new printer replaces any
2170 ** The "maint set python print-stack on|off" command has been
2171 deprecated and will be deleted in GDB 7.5.
2172 A new command: "set python print-stack none|full|message" has
2173 replaced it. Additionally, the default for "print-stack" is
2174 now "message", which just prints the error message without
2177 ** A prompt substitution hook (prompt_hook) is now available to the
2180 ** A new Python module, gdb.prompt has been added to the GDB Python
2181 modules library. This module provides functionality for
2182 escape sequences in prompts (used by set/show
2183 extended-prompt). These escape sequences are replaced by their
2184 corresponding value.
2186 ** Python commands and convenience-functions located in
2187 'data-directory'/python/gdb/command and
2188 'data-directory'/python/gdb/function are now automatically loaded
2191 ** Blocks now provide four new attributes. global_block and
2192 static_block will return the global and static blocks
2193 respectively. is_static and is_global are boolean attributes
2194 that indicate if the block is one of those two types.
2196 ** Symbols now provide the "type" attribute, the type of the symbol.
2198 ** The "gdb.breakpoint" function has been deprecated in favor of
2201 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2202 of a function. This class is based on the "finish" command
2203 available in the CLI.
2205 ** Type objects for struct and union types now allow access to
2206 the fields using standard Python dictionary (mapping) methods.
2207 For example, "some_type['myfield']" now works, as does
2208 "some_type.items()".
2210 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2213 ** A new function, "deep_items" has been added to the gdb.types
2214 module in the GDB Python modules library. This function returns
2215 an iterator over the fields of a struct or union type. Unlike
2216 the standard Python "iteritems" method, it will recursively traverse
2217 any anonymous fields.
2221 ** "*stopped" events can report several new "reason"s, such as
2224 ** Breakpoint changes are now notified using new async records, like
2225 "=breakpoint-modified".
2227 ** New command -ada-task-info.
2229 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2230 $sdir specifies the default system locations of shared libraries.
2231 $pdir specifies the directory where the libpthread used by the application
2234 GDB no longer looks in $sdir and $pdir after it has searched the directories
2235 mentioned in libthread-db-search-path. If you want to search those
2236 directories, they must be specified in libthread-db-search-path.
2237 The default value of libthread-db-search-path on GNU/Linux and Solaris
2238 systems is now "$sdir:$pdir".
2240 $pdir is not supported by gdbserver, it is currently ignored.
2241 $sdir is supported by gdbserver.
2243 * New configure option --with-iconv-bin.
2244 When using the internationalization support like the one in the GNU C
2245 library, GDB will invoke the "iconv" program to get a list of supported
2246 character sets. If this program lives in a non-standard location, one can
2247 use this option to specify where to find it.
2249 * When natively debugging programs on PowerPC BookE processors running
2250 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2251 watchpoints, which specify a mask in addition to an address to watch.
2252 The mask specifies that some bits of an address (the bits which are
2253 reset in the mask) should be ignored when matching the address accessed
2254 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2255 section in the user manual for more details.
2257 * The new option --once causes GDBserver to stop listening for connections once
2258 the first connection is made. The listening port used by GDBserver will
2259 become available after that.
2261 * New commands "info macros" and "alias" have been added.
2263 * New function parameters suffix @entry specifies value of function parameter
2264 at the time the function got called. Entry values are available only since
2270 "!" is now an alias of the "shell" command.
2271 Note that no space is needed between "!" and SHELL COMMAND.
2275 watch EXPRESSION mask MASK_VALUE
2276 The watch command now supports the mask argument which allows creation
2277 of masked watchpoints, if the current architecture supports this feature.
2279 info auto-load-scripts [REGEXP]
2280 This command was formerly named "maintenance print section-scripts".
2281 It is now generally useful and is no longer a maintenance-only command.
2283 info macro [-all] [--] MACRO
2284 The info macro command has new options `-all' and `--'. The first for
2285 printing all definitions of a macro. The second for explicitly specifying
2286 the end of arguments and the beginning of the macro name in case the macro
2287 name starts with a hyphen.
2289 collect[/s] EXPRESSIONS
2290 The tracepoint collect command now takes an optional modifier "/s"
2291 that directs it to dereference pointer-to-character types and
2292 collect the bytes of memory up to a zero byte. The behavior is
2293 similar to what you see when you use the regular print command on a
2294 string. An optional integer following the "/s" sets a bound on the
2295 number of bytes that will be collected.
2298 The trace start command now interprets any supplied arguments as a
2299 note to be recorded with the trace run, with an effect similar to
2300 setting the variable trace-notes.
2303 The trace stop command now interprets any arguments as a note to be
2304 mentioned along with the tstatus report that the trace was stopped
2305 with a command. The effect is similar to setting the variable
2308 * Tracepoints can now be enabled and disabled at any time after a trace
2309 experiment has been started using the standard "enable" and "disable"
2310 commands. It is now possible to start a trace experiment with no enabled
2311 tracepoints; GDB will display a warning, but will allow the experiment to
2312 begin, assuming that tracepoints will be enabled as needed while the trace
2315 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2316 locations with 4-byte instructions, when they were previously
2317 limited to locations with instructions of 5 bytes or longer.
2321 set debug dwarf2-read
2322 show debug dwarf2-read
2323 Turns on or off display of debugging messages related to reading
2324 DWARF debug info. The default is off.
2326 set debug symtab-create
2327 show debug symtab-create
2328 Turns on or off display of debugging messages related to symbol table
2329 creation. The default is off.
2332 show extended-prompt
2333 Set the GDB prompt, and allow escape sequences to be inserted to
2334 display miscellaneous information (see 'help set extended-prompt'
2335 for the list of sequences). This prompt (and any information
2336 accessed through the escape sequences) is updated every time the
2337 prompt is displayed.
2339 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2340 show print entry-values
2341 Set printing of frame argument values at function entry. In some cases
2342 GDB can determine the value of function argument which was passed by the
2343 function caller, even if the value was modified inside the called function.
2345 set debug entry-values
2346 show debug entry-values
2347 Control display of debugging info for determining frame argument values at
2348 function entry and virtual tail call frames.
2350 set basenames-may-differ
2351 show basenames-may-differ
2352 Set whether a source file may have multiple base names.
2353 (A "base name" is the name of a file with the directory part removed.
2354 Example: The base name of "/home/user/hello.c" is "hello.c".)
2355 If set, GDB will canonicalize file names (e.g., expand symlinks)
2356 before comparing them. Canonicalization is an expensive operation,
2357 but it allows the same file be known by more than one base name.
2358 If not set (the default), all source files are assumed to have just
2359 one base name, and gdb will do file name comparisons more efficiently.
2365 Set a user name and notes for the current and any future trace runs.
2366 This is useful for long-running and/or disconnected traces, to
2367 inform others (or yourself) as to who is running the trace, supply
2368 contact information, or otherwise explain what is going on.
2370 set trace-stop-notes
2371 show trace-stop-notes
2372 Set a note attached to the trace run, that is displayed when the
2373 trace has been stopped by a tstop command. This is useful for
2374 instance as an explanation, if you are stopping a trace run that was
2375 started by someone else.
2377 * New remote packets
2381 Dynamically enable a tracepoint in a started trace experiment.
2385 Dynamically disable a tracepoint in a started trace experiment.
2389 Set the user and notes of the trace run.
2393 Query the current status of a tracepoint.
2397 Query the minimum length of instruction at which a fast tracepoint may
2400 * Dcache size (number of lines) and line-size are now runtime-configurable
2401 via "set dcache line" and "set dcache line-size" commands.
2405 Texas Instruments TMS320C6x tic6x-*-*
2409 Renesas RL78 rl78-*-elf
2411 *** Changes in GDB 7.3.1
2413 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2415 *** Changes in GDB 7.3
2417 * GDB has a new command: "thread find [REGEXP]".
2418 It finds the thread id whose name, target id, or thread extra info
2419 matches the given regular expression.
2421 * The "catch syscall" command now works on mips*-linux* targets.
2423 * The -data-disassemble MI command now supports modes 2 and 3 for
2424 dumping the instruction opcodes.
2426 * New command line options
2428 -data-directory DIR Specify DIR as the "data-directory".
2429 This is mostly for testing purposes.
2431 * The "maint set python auto-load on|off" command has been renamed to
2432 "set auto-load-scripts on|off".
2434 * GDB has a new command: "set directories".
2435 It is like the "dir" command except that it replaces the
2436 source path list instead of augmenting it.
2438 * GDB now understands thread names.
2440 On GNU/Linux, "info threads" will display the thread name as set by
2441 prctl or pthread_setname_np.
2443 There is also a new command, "thread name", which can be used to
2444 assign a name internally for GDB to display.
2447 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2448 has been integrated into GDB.
2452 ** The function gdb.Write now accepts an optional keyword 'stream'.
2453 This keyword, when provided, will direct the output to either
2454 stdout, stderr, or GDB's logging output.
2456 ** Parameters can now be be sub-classed in Python, and in particular
2457 you may implement the get_set_doc and get_show_doc functions.
2458 This improves how Parameter set/show documentation is processed
2459 and allows for more dynamic content.
2461 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2462 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2463 have an is_valid method.
2465 ** Breakpoints can now be sub-classed in Python, and in particular
2466 you may implement a 'stop' function that is executed each time
2467 the inferior reaches that breakpoint.
2469 ** New function gdb.lookup_global_symbol looks up a global symbol.
2471 ** GDB values in Python are now callable if the value represents a
2472 function. For example, if 'some_value' represents a function that
2473 takes two integer parameters and returns a value, you can call
2474 that function like so:
2476 result = some_value (10,20)
2478 ** Module gdb.types has been added.
2479 It contains a collection of utilities for working with gdb.Types objects:
2480 get_basic_type, has_field, make_enum_dict.
2482 ** Module gdb.printing has been added.
2483 It contains utilities for writing and registering pretty-printers.
2484 New classes: PrettyPrinter, SubPrettyPrinter,
2485 RegexpCollectionPrettyPrinter.
2486 New function: register_pretty_printer.
2488 ** New commands "info pretty-printers", "enable pretty-printer" and
2489 "disable pretty-printer" have been added.
2491 ** gdb.parameter("directories") is now available.
2493 ** New function gdb.newest_frame returns the newest frame in the
2496 ** The gdb.InferiorThread class has a new "name" attribute. This
2497 holds the thread's name.
2499 ** Python Support for Inferior events.
2500 Python scripts can add observers to be notified of events
2501 occurring in the process being debugged.
2502 The following events are currently supported:
2503 - gdb.events.cont Continue event.
2504 - gdb.events.exited Inferior exited event.
2505 - gdb.events.stop Signal received, and Breakpoint hit events.
2509 ** GDB now puts template parameters in scope when debugging in an
2510 instantiation. For example, if you have:
2512 template<int X> int func (void) { return X; }
2514 then if you step into func<5>, "print X" will show "5". This
2515 feature requires proper debuginfo support from the compiler; it
2516 was added to GCC 4.5.
2518 ** The motion commands "next", "finish", "until", and "advance" now
2519 work better when exceptions are thrown. In particular, GDB will
2520 no longer lose control of the inferior; instead, the GDB will
2521 stop the inferior at the point at which the exception is caught.
2522 This functionality requires a change in the exception handling
2523 code that was introduced in GCC 4.5.
2525 * GDB now follows GCC's rules on accessing volatile objects when
2526 reading or writing target state during expression evaluation.
2527 One notable difference to prior behavior is that "print x = 0"
2528 no longer generates a read of x; the value of the assignment is
2529 now always taken directly from the value being assigned.
2531 * GDB now has some support for using labels in the program's source in
2532 linespecs. For instance, you can use "advance label" to continue
2533 execution to a label.
2535 * GDB now has support for reading and writing a new .gdb_index
2536 section. This section holds a fast index of DWARF debugging
2537 information and can be used to greatly speed up GDB startup and
2538 operation. See the documentation for `save gdb-index' for details.
2540 * The "watch" command now accepts an optional "-location" argument.
2541 When used, this causes GDB to watch the memory referred to by the
2542 expression. Such a watchpoint is never deleted due to it going out
2545 * GDB now supports thread debugging of core dumps on GNU/Linux.
2547 GDB now activates thread debugging using the libthread_db library
2548 when debugging GNU/Linux core dumps, similarly to when debugging
2549 live processes. As a result, when debugging a core dump file, GDB
2550 is now able to display pthread_t ids of threads. For example, "info
2551 threads" shows the same output as when debugging the process when it
2552 was live. In earlier releases, you'd see something like this:
2555 * 1 LWP 6780 main () at main.c:10
2557 While now you see this:
2560 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2562 It is also now possible to inspect TLS variables when debugging core
2565 When debugging a core dump generated on a machine other than the one
2566 used to run GDB, you may need to point GDB at the correct
2567 libthread_db library with the "set libthread-db-search-path"
2568 command. See the user manual for more details on this command.
2570 * When natively debugging programs on PowerPC BookE processors running
2571 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2572 which stop execution of the inferior whenever it executes an instruction
2573 at any address within the specified range. See the "PowerPC Embedded"
2574 section in the user manual for more details.
2576 * New features in the GDB remote stub, GDBserver
2578 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2579 and i686 LynxOS (version 5.x).
2581 ** GDBserver is now supported on Blackfin Linux.
2583 * New native configurations
2585 ia64 HP-UX ia64-*-hpux*
2589 Analog Devices, Inc. Blackfin Processor bfin-*
2591 * Ada task switching is now supported on sparc-elf targets when
2592 debugging a program using the Ravenscar Profile. For more information,
2593 see the "Tasking Support when using the Ravenscar Profile" section
2594 in the GDB user manual.
2596 * Guile support was removed.
2598 * New features in the GNU simulator
2600 ** The --map-info flag lists all known core mappings.
2602 ** CFI flashes may be simulated via the "cfi" device.
2604 *** Changes in GDB 7.2
2606 * Shared library support for remote targets by default
2608 When GDB is configured for a generic, non-OS specific target, like
2609 for example, --target=arm-eabi or one of the many *-*-elf targets,
2610 GDB now queries remote stubs for loaded shared libraries using the
2611 `qXfer:libraries:read' packet. Previously, shared library support
2612 was always disabled for such configurations.
2616 ** Argument Dependent Lookup (ADL)
2618 In C++ ADL lookup directs function search to the namespaces of its
2619 arguments even if the namespace has not been imported.
2629 Here the compiler will search for `foo' in the namespace of 'b'
2630 and find A::foo. GDB now supports this. This construct is commonly
2631 used in the Standard Template Library for operators.
2633 ** Improved User Defined Operator Support
2635 In addition to member operators, GDB now supports lookup of operators
2636 defined in a namespace and imported with a `using' directive, operators
2637 defined in the global scope, operators imported implicitly from an
2638 anonymous namespace, and the ADL operators mentioned in the previous
2640 GDB now also supports proper overload resolution for all the previously
2641 mentioned flavors of operators.
2643 ** static const class members
2645 Printing of static const class members that are initialized in the
2646 class definition has been fixed.
2648 * Windows Thread Information Block access.
2650 On Windows targets, GDB now supports displaying the Windows Thread
2651 Information Block (TIB) structure. This structure is visible either
2652 by using the new command `info w32 thread-information-block' or, by
2653 dereferencing the new convenience variable named `$_tlb', a
2654 thread-specific pointer to the TIB. This feature is also supported
2655 when remote debugging using GDBserver.
2657 * Static tracepoints
2659 Static tracepoints are calls in the user program into a tracing
2660 library. One such library is a port of the LTTng kernel tracer to
2661 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2662 When debugging with GDBserver, GDB now supports combining the GDB
2663 tracepoint machinery with such libraries. For example: the user can
2664 use GDB to probe a static tracepoint marker (a call from the user
2665 program into the tracing library) with the new "strace" command (see
2666 "New commands" below). This creates a "static tracepoint" in the
2667 breakpoint list, that can be manipulated with the same feature set
2668 as fast and regular tracepoints. E.g., collect registers, local and
2669 global variables, collect trace state variables, and define
2670 tracepoint conditions. In addition, the user can collect extra
2671 static tracepoint marker specific data, by collecting the new
2672 $_sdata internal variable. When analyzing the trace buffer, you can
2673 inspect $_sdata like any other variable available to GDB. For more
2674 information, see the "Tracepoints" chapter in GDB user manual. New
2675 remote packets have been defined to support static tracepoints, see
2676 the "New remote packets" section below.
2678 * Better reconstruction of tracepoints after disconnected tracing
2680 GDB will attempt to download the original source form of tracepoint
2681 definitions when starting a trace run, and then will upload these
2682 upon reconnection to the target, resulting in a more accurate
2683 reconstruction of the tracepoints that are in use on the target.
2687 You can now exercise direct control over the ways that GDB can
2688 affect your program. For instance, you can disallow the setting of
2689 breakpoints, so that the program can run continuously (assuming
2690 non-stop mode). In addition, the "observer" variable is available
2691 to switch all of the different controls; in observer mode, GDB
2692 cannot affect the target's behavior at all, which is useful for
2693 tasks like diagnosing live systems in the field.
2695 * The new convenience variable $_thread holds the number of the
2698 * New remote packets
2702 Return the address of the Windows Thread Information Block of a given thread.
2706 In response to several of the tracepoint packets, the target may now
2707 also respond with a number of intermediate `qRelocInsn' request
2708 packets before the final result packet, to have GDB handle
2709 relocating an instruction to execute at a different address. This
2710 is particularly useful for stubs that support fast tracepoints. GDB
2711 reports support for this feature in the qSupported packet.
2715 List static tracepoint markers in the target program.
2719 List static tracepoint markers at a given address in the target
2722 qXfer:statictrace:read
2724 Read the static trace data collected (by a `collect $_sdata'
2725 tracepoint action). The remote stub reports support for this packet
2726 to gdb's qSupported query.
2730 Send the current settings of GDB's permission flags.
2734 Send part of the source (textual) form of a tracepoint definition,
2735 which includes location, conditional, and action list.
2737 * The source command now accepts a -s option to force searching for the
2738 script in the source search path even if the script name specifies
2741 * New features in the GDB remote stub, GDBserver
2743 - GDBserver now support tracepoints (including fast tracepoints, and
2744 static tracepoints). The feature is currently supported by the
2745 i386-linux and amd64-linux builds. See the "Tracepoints support
2746 in gdbserver" section in the manual for more information.
2748 GDBserver JIT compiles the tracepoint's conditional agent
2749 expression bytecode into native code whenever possible for low
2750 overhead dynamic tracepoints conditionals. For such tracepoints,
2751 an expression that examines program state is evaluated when the
2752 tracepoint is reached, in order to determine whether to capture
2753 trace data. If the condition is simple and false, processing the
2754 tracepoint finishes very quickly and no data is gathered.
2756 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2757 for static tracepoints support.
2759 - GDBserver now supports x86_64 Windows 64-bit debugging.
2761 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2762 it understands register description.
2764 * The --batch flag now disables pagination and queries.
2766 * X86 general purpose registers
2768 GDB now supports reading/writing byte, word and double-word x86
2769 general purpose registers directly. This means you can use, say,
2770 $ah or $ax to refer, respectively, to the byte register AH and
2771 16-bit word register AX that are actually portions of the 32-bit
2772 register EAX or 64-bit register RAX.
2774 * The `commands' command now accepts a range of breakpoints to modify.
2775 A plain `commands' following a command that creates multiple
2776 breakpoints affects all the breakpoints set by that command. This
2777 applies to breakpoints set by `rbreak', and also applies when a
2778 single `break' command creates multiple breakpoints (e.g.,
2779 breakpoints on overloaded c++ functions).
2781 * The `rbreak' command now accepts a filename specification as part of
2782 its argument, limiting the functions selected by the regex to those
2783 in the specified file.
2785 * Support for remote debugging Windows and SymbianOS shared libraries
2786 from Unix hosts has been improved. Non Windows GDB builds now can
2787 understand target reported file names that follow MS-DOS based file
2788 system semantics, such as file names that include drive letters and
2789 use the backslash character as directory separator. This makes it
2790 possible to transparently use the "set sysroot" and "set
2791 solib-search-path" on Unix hosts to point as host copies of the
2792 target's shared libraries. See the new command "set
2793 target-file-system-kind" described below, and the "Commands to
2794 specify files" section in the user manual for more information.
2798 eval template, expressions...
2799 Convert the values of one or more expressions under the control
2800 of the string template to a command line, and call it.
2802 set target-file-system-kind unix|dos-based|auto
2803 show target-file-system-kind
2804 Set or show the assumed file system kind for target reported file
2807 save breakpoints <filename>
2808 Save all current breakpoint definitions to a file suitable for use
2809 in a later debugging session. To read the saved breakpoint
2810 definitions, use the `source' command.
2812 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2815 info static-tracepoint-markers
2816 Display information about static tracepoint markers in the target.
2818 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2819 Define a static tracepoint by probing a marker at the given
2820 function, line, address, or marker ID.
2824 Enable and disable observer mode.
2826 set may-write-registers on|off
2827 set may-write-memory on|off
2828 set may-insert-breakpoints on|off
2829 set may-insert-tracepoints on|off
2830 set may-insert-fast-tracepoints on|off
2831 set may-interrupt on|off
2832 Set individual permissions for GDB effects on the target. Note that
2833 some of these settings can have undesirable or surprising
2834 consequences, particularly when changed in the middle of a session.
2835 For instance, disabling the writing of memory can prevent
2836 breakpoints from being inserted, cause single-stepping to fail, or
2837 even crash your program, if you disable after breakpoints have been
2838 inserted. However, GDB should not crash.
2840 set record memory-query on|off
2841 show record memory-query
2842 Control whether to stop the inferior if memory changes caused
2843 by an instruction cannot be recorded.
2848 The disassemble command now supports "start,+length" form of two arguments.
2852 ** GDB now provides a new directory location, called the python directory,
2853 where Python scripts written for GDB can be installed. The location
2854 of that directory is <data-directory>/python, where <data-directory>
2855 is the GDB data directory. For more details, see section `Scripting
2856 GDB using Python' in the manual.
2858 ** The GDB Python API now has access to breakpoints, symbols, symbol
2859 tables, program spaces, inferiors, threads and frame's code blocks.
2860 Additionally, GDB Parameters can now be created from the API, and
2861 manipulated via set/show in the CLI.
2863 ** New functions gdb.target_charset, gdb.target_wide_charset,
2864 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2866 ** New exception gdb.GdbError.
2868 ** Pretty-printers are now also looked up in the current program space.
2870 ** Pretty-printers can now be individually enabled and disabled.
2872 ** GDB now looks for names of Python scripts to auto-load in a
2873 special section named `.debug_gdb_scripts', in addition to looking
2874 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2876 * Tracepoint actions were unified with breakpoint commands. In particular,
2877 there are no longer differences in "info break" output for breakpoints and
2878 tracepoints and the "commands" command can be used for both tracepoints and
2879 regular breakpoints.
2883 ARM Symbian arm*-*-symbianelf*
2885 * D language support.
2886 GDB now supports debugging programs written in the D programming
2889 * GDB now supports the extended ptrace interface for PowerPC which is
2890 available since Linux kernel version 2.6.34. This automatically enables
2891 any hardware breakpoints and additional hardware watchpoints available in
2892 the processor. The old ptrace interface exposes just one hardware
2893 watchpoint and no hardware breakpoints.
2895 * GDB is now able to use the Data Value Compare (DVC) register available on
2896 embedded PowerPC processors to implement in hardware simple watchpoint
2897 conditions of the form:
2899 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2901 This works in native GDB running on Linux kernels with the extended ptrace
2902 interface mentioned above.
2904 *** Changes in GDB 7.1
2908 ** Namespace Support
2910 GDB now supports importing of namespaces in C++. This enables the
2911 user to inspect variables from imported namespaces. Support for
2912 namepace aliasing has also been added. So, if a namespace is
2913 aliased in the current scope (e.g. namepace C=A; ) the user can
2914 print variables using the alias (e.g. (gdb) print C::x).
2918 All known bugs relating to the printing of virtual base class were
2919 fixed. It is now possible to call overloaded static methods using a
2924 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2925 and reinterpret_cast<> are now handled by the C++ expression parser.
2929 Xilinx MicroBlaze microblaze-*-*
2934 Xilinx MicroBlaze microblaze
2937 * Multi-program debugging.
2939 GDB now has support for multi-program (a.k.a. multi-executable or
2940 multi-exec) debugging. This allows for debugging multiple inferiors
2941 simultaneously each running a different program under the same GDB
2942 session. See "Debugging Multiple Inferiors and Programs" in the
2943 manual for more information. This implied some user visible changes
2944 in the multi-inferior support. For example, "info inferiors" now
2945 lists inferiors that are not running yet or that have exited
2946 already. See also "New commands" and "New options" below.
2948 * New tracing features
2950 GDB's tracepoint facility now includes several new features:
2952 ** Trace state variables
2954 GDB tracepoints now include support for trace state variables, which
2955 are variables managed by the target agent during a tracing
2956 experiment. They are useful for tracepoints that trigger each
2957 other, so for instance one tracepoint can count hits in a variable,
2958 and then a second tracepoint has a condition that is true when the
2959 count reaches a particular value. Trace state variables share the
2960 $-syntax of GDB convenience variables, and can appear in both
2961 tracepoint actions and condition expressions. Use the "tvariable"
2962 command to create, and "info tvariables" to view; see "Trace State
2963 Variables" in the manual for more detail.
2967 GDB now includes an option for defining fast tracepoints, which
2968 targets may implement more efficiently, such as by installing a jump
2969 into the target agent rather than a trap instruction. The resulting
2970 speedup can be by two orders of magnitude or more, although the
2971 tradeoff is that some program locations on some target architectures
2972 might not allow fast tracepoint installation, for instance if the
2973 instruction to be replaced is shorter than the jump. To request a
2974 fast tracepoint, use the "ftrace" command, with syntax identical to
2975 the regular trace command.
2977 ** Disconnected tracing
2979 It is now possible to detach GDB from the target while it is running
2980 a trace experiment, then reconnect later to see how the experiment
2981 is going. In addition, a new variable disconnected-tracing lets you
2982 tell the target agent whether to continue running a trace if the
2983 connection is lost unexpectedly.
2987 GDB now has the ability to save the trace buffer into a file, and
2988 then use that file as a target, similarly to you can do with
2989 corefiles. You can select trace frames, print data that was
2990 collected in them, and use tstatus to display the state of the
2991 tracing run at the moment that it was saved. To create a trace
2992 file, use "tsave <filename>", and to use it, do "target tfile
2995 ** Circular trace buffer
2997 You can ask the target agent to handle the trace buffer as a
2998 circular buffer, discarding the oldest trace frames to make room for
2999 newer ones, by setting circular-trace-buffer to on. This feature may
3000 not be available for all target agents.
3005 The disassemble command, when invoked with two arguments, now requires
3006 the arguments to be comma-separated.
3009 The info variables command now displays variable definitions. Files
3010 which only declare a variable are not shown.
3013 The source command is now capable of sourcing Python scripts.
3014 This feature is dependent on the debugger being build with Python
3017 Related to this enhancement is also the introduction of a new command
3018 "set script-extension" (see below).
3020 * New commands (for set/show, see "New options" below)
3022 record save [<FILENAME>]
3023 Save a file (in core file format) containing the process record
3024 execution log for replay debugging at a later time.
3026 record restore <FILENAME>
3027 Restore the process record execution log that was saved at an
3028 earlier time, for replay debugging.
3030 add-inferior [-copies <N>] [-exec <FILENAME>]
3033 clone-inferior [-copies <N>] [ID]
3034 Make a new inferior ready to execute the same program another
3035 inferior has loaded.
3040 maint info program-spaces
3041 List the program spaces loaded into GDB.
3043 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3044 show remote interrupt-sequence
3045 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3046 as the sequence to the remote target in order to interrupt the execution.
3047 Ctrl-C is a default. Some system prefers BREAK which is high level of
3048 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3049 Magic SysRq g. It is BREAK signal and character 'g'.
3051 set remote interrupt-on-connect [on | off]
3052 show remote interrupt-on-connect
3053 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3054 remote target when gdb connects to it. This is needed when you debug
3057 set remotebreak [on | off]
3059 Deprecated. Use "set/show remote interrupt-sequence" instead.
3061 tvariable $NAME [ = EXP ]
3062 Create or modify a trace state variable.
3065 List trace state variables and their values.
3067 delete tvariable $NAME ...
3068 Delete one or more trace state variables.
3071 Evaluate the given expressions without collecting anything into the
3072 trace buffer. (Valid in tracepoint actions only.)
3074 ftrace FN / FILE:LINE / *ADDR
3075 Define a fast tracepoint at the given function, line, or address.
3077 * New expression syntax
3079 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3080 GDB now parses 0b101010 identically with 42.
3084 set follow-exec-mode new|same
3085 show follow-exec-mode
3086 Control whether GDB reuses the same inferior across an exec call or
3087 creates a new one. This is useful to be able to restart the old
3088 executable after the inferior having done an exec call.
3090 set default-collect EXPR, ...
3091 show default-collect
3092 Define a list of expressions to be collected at each tracepoint.
3093 This is a useful way to ensure essential items are not overlooked,
3094 such as registers or a critical global variable.
3096 set disconnected-tracing
3097 show disconnected-tracing
3098 If set to 1, the target is instructed to continue tracing if it
3099 loses its connection to GDB. If 0, the target is to stop tracing
3102 set circular-trace-buffer
3103 show circular-trace-buffer
3104 If set to on, the target is instructed to use a circular trace buffer
3105 and discard the oldest trace frames instead of stopping the trace due
3106 to a full trace buffer. If set to off, the trace stops when the buffer
3107 fills up. Some targets may not support this.
3109 set script-extension off|soft|strict
3110 show script-extension
3111 If set to "off", the debugger does not perform any script language
3112 recognition, and all sourced files are assumed to be GDB scripts.
3113 If set to "soft" (the default), files are sourced according to
3114 filename extension, falling back to GDB scripts if the first
3116 If set to "strict", files are sourced according to filename extension.
3118 set ada trust-PAD-over-XVS on|off
3119 show ada trust-PAD-over-XVS
3120 If off, activate a workaround against a bug in the debugging information
3121 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3122 the GCC sources for more information about the GNAT encoding and
3123 PAD types in particular). It is always safe to set this option to
3124 off, but this introduces a slight performance penalty. The default
3127 * Python API Improvements
3129 ** GDB provides the new class gdb.LazyString. This is useful in
3130 some pretty-printing cases. The new method gdb.Value.lazy_string
3131 provides a simple way to create objects of this type.
3133 ** The fields returned by gdb.Type.fields now have an
3134 `is_base_class' attribute.
3136 ** The new method gdb.Type.range returns the range of an array type.
3138 ** The new method gdb.parse_and_eval can be used to parse and
3139 evaluate an expression.
3141 * New remote packets
3144 Define a trace state variable.
3147 Get the current value of a trace state variable.
3150 Set desired tracing behavior upon disconnection.
3153 Set the trace buffer to be linear or circular.
3156 Get data about the tracepoints currently in use.
3160 Process record now works correctly with hardware watchpoints.
3162 Multiple bug fixes have been made to the mips-irix port, making it
3163 much more reliable. In particular:
3164 - Debugging threaded applications is now possible again. Previously,
3165 GDB would hang while starting the program, or while waiting for
3166 the program to stop at a breakpoint.
3167 - Attaching to a running process no longer hangs.
3168 - An error occurring while loading a core file has been fixed.
3169 - Changing the value of the PC register now works again. This fixes
3170 problems observed when using the "jump" command, or when calling
3171 a function from GDB, or even when assigning a new value to $pc.
3172 - With the "finish" and "return" commands, the return value for functions
3173 returning a small array is now correctly printed.
3174 - It is now possible to break on shared library code which gets executed
3175 during a shared library init phase (code executed while executing
3176 their .init section). Previously, the breakpoint would have no effect.
3177 - GDB is now able to backtrace through the signal handler for
3178 non-threaded programs.
3180 PIE (Position Independent Executable) programs debugging is now supported.
3181 This includes debugging execution of PIC (Position Independent Code) shared
3182 libraries although for that, it should be possible to run such libraries as an
3185 *** Changes in GDB 7.0
3187 * GDB now has an interface for JIT compilation. Applications that
3188 dynamically generate code can create symbol files in memory and register
3189 them with GDB. For users, the feature should work transparently, and
3190 for JIT developers, the interface is documented in the GDB manual in the
3191 "JIT Compilation Interface" chapter.
3193 * Tracepoints may now be conditional. The syntax is as for
3194 breakpoints; either an "if" clause appended to the "trace" command,
3195 or the "condition" command is available. GDB sends the condition to
3196 the target for evaluation using the same bytecode format as is used
3197 for tracepoint actions.
3199 * The disassemble command now supports: an optional /r modifier, print the
3200 raw instructions in hex as well as in symbolic form, and an optional /m
3201 modifier to print mixed source+assembly.
3203 * Process record and replay
3205 In a architecture environment that supports ``process record and
3206 replay'', ``process record and replay'' target can record a log of
3207 the process execution, and replay it with both forward and reverse
3210 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3211 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3212 set execution-direction {forward|reverse}, for targets that support
3215 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3216 feature is available with a native GDB running on kernel version
3219 * GDB now has support for multi-byte and wide character sets on the
3220 target. Strings whose character type is wchar_t, char16_t, or
3221 char32_t are now correctly printed. GDB supports wide- and unicode-
3222 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3223 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3224 `printf'. This feature requires iconv to work properly; if your
3225 system does not have a working iconv, GDB can use GNU libiconv. See
3226 the installation instructions for more information.
3228 * GDB now supports automatic retrieval of shared library files from
3229 remote targets. To use this feature, specify a system root that begins
3230 with the `remote:' prefix, either via the `set sysroot' command or via
3231 the `--with-sysroot' configure-time option.
3233 * "info sharedlibrary" now takes an optional regex of libraries to show,
3234 and it now reports if a shared library has no debugging information.
3236 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3237 now complete on file names.
3239 * When completing in expressions, gdb will attempt to limit
3240 completions to allowable structure or union fields, where appropriate.
3241 For instance, consider:
3243 # struct example { int f1; double f2; };
3244 # struct example variable;
3247 If the user types TAB at the end of this command line, the available
3248 completions will be "f1" and "f2".
3250 * Inlined functions are now supported. They show up in backtraces, and
3251 the "step", "next", and "finish" commands handle them automatically.
3253 * GDB now supports the token-splicing (##) and stringification (#)
3254 operators when expanding macros. It also supports variable-arity
3257 * GDB now supports inspecting extra signal information, exported by
3258 the new $_siginfo convenience variable. The feature is currently
3259 implemented on linux ARM, i386 and amd64.
3261 * GDB can now display the VFP floating point registers and NEON vector
3262 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3263 can provide these registers (requires Linux 2.6.30 or later). Remote
3264 and simulator targets may also provide them.
3266 * New remote packets
3269 Search memory for a sequence of bytes.
3272 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3273 operation over reliable transport links. Use of this packet is
3274 controlled by the `set remote noack-packet' command.
3277 Kill the process with the specified process ID. Use this in preference
3278 to `k' when multiprocess protocol extensions are supported.
3281 Obtains additional operating system information
3285 Read or write additional signal information.
3287 * Removed remote protocol undocumented extension
3289 An undocumented extension to the remote protocol's `S' stop reply
3290 packet that permited the stub to pass a process id was removed.
3291 Remote servers should use the `T' stop reply packet instead.
3293 * GDB now supports multiple function calling conventions according to the
3294 DWARF-2 DW_AT_calling_convention function attribute.
3296 * The SH target utilizes the aforementioned change to distinguish between gcc
3297 and Renesas calling convention. It also adds the new CLI commands
3298 `set/show sh calling-convention'.
3300 * GDB can now read compressed debug sections, as produced by GNU gold
3301 with the --compress-debug-sections=zlib flag.
3303 * 64-bit core files are now supported on AIX.
3305 * Thread switching is now supported on Tru64.
3307 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3308 which will be allocated using malloc later in program execution.
3310 * The qXfer:libraries:read remote procotol packet now allows passing a
3311 list of section offsets.
3313 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3314 conditions handling signals delivered during attach or thread creation
3315 have also been fixed.
3317 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3318 From the user's standpoint, all unqualified instances of True and False
3319 are treated as the standard definitions, regardless of context.
3321 * GDB now parses C++ symbol and type names more flexibly. For
3324 template<typename T> class C { };
3327 GDB will now correctly handle all of:
3329 ptype C<char const *>
3330 ptype C<char const*>
3331 ptype C<const char *>
3332 ptype C<const char*>
3334 * New features in the GDB remote stub, gdbserver
3336 - The "--wrapper" command-line argument tells gdbserver to use a
3337 wrapper program to launch programs for debugging.
3339 - On PowerPC and S/390 targets, it is now possible to use a single
3340 gdbserver executable to debug both 32-bit and 64-bit programs.
3341 (This requires gdbserver itself to be built as a 64-bit executable.)
3343 - gdbserver uses the new noack protocol mode for TCP connections to
3344 reduce communications latency, if also supported and enabled in GDB.
3346 - Support for the sparc64-linux-gnu target is now included in
3349 - The amd64-linux build of gdbserver now supports debugging both
3350 32-bit and 64-bit programs.
3352 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3353 now support hardware watchpoints, and will use them automatically
3358 GDB now has support for scripting using Python. Whether this is
3359 available is determined at configure time.
3361 New GDB commands can now be written in Python.
3363 * Ada tasking support
3365 Ada tasks can now be inspected in GDB. The following commands have
3369 Print the list of Ada tasks.
3371 Print detailed information about task number N.
3373 Print the task number of the current task.
3375 Switch the context of debugging to task number N.
3377 * Support for user-defined prefixed commands. The "define" command can
3378 add new commands to existing prefixes, e.g. "target".
3380 * Multi-inferior, multi-process debugging.
3382 GDB now has generalized support for multi-inferior debugging. See
3383 "Debugging Multiple Inferiors" in the manual for more information.
3384 Although availability still depends on target support, the command
3385 set is more uniform now. The GNU/Linux specific multi-forks support
3386 has been migrated to this new framework. This implied some user
3387 visible changes; see "New commands" and also "Removed commands"
3390 * Target descriptions can now describe the target OS ABI. See the
3391 "Target Description Format" section in the user manual for more
3394 * Target descriptions can now describe "compatible" architectures
3395 to indicate that the target can execute applications for a different
3396 architecture in addition to those for the main target architecture.
3397 See the "Target Description Format" section in the user manual for
3400 * Multi-architecture debugging.
3402 GDB now includes general supports for debugging applications on
3403 hybrid systems that use more than one single processor architecture
3404 at the same time. Each such hybrid architecture still requires
3405 specific support to be added. The only hybrid architecture supported
3406 in this version of GDB is the Cell Broadband Engine.
3408 * GDB now supports integrated debugging of Cell/B.E. applications that
3409 use both the PPU and SPU architectures. To enable support for hybrid
3410 Cell/B.E. debugging, you need to configure GDB to support both the
3411 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3412 --enable-targets configure option.
3414 * Non-stop mode debugging.
3416 For some targets, GDB now supports an optional mode of operation in
3417 which you can examine stopped threads while other threads continue
3418 to execute freely. This is referred to as non-stop mode, with the
3419 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3420 section in the user manual for more information.
3422 To be able to support remote non-stop debugging, a remote stub needs
3423 to implement the non-stop mode remote protocol extensions, as
3424 described in the "Remote Non-Stop" section of the user manual. The
3425 GDB remote stub, gdbserver, has been adjusted to support these
3426 extensions on linux targets.
3428 * New commands (for set/show, see "New options" below)
3430 catch syscall [NAME(S) | NUMBER(S)]
3431 Catch system calls. Arguments, which should be names of system
3432 calls or their numbers, mean catch only those syscalls. Without
3433 arguments, every syscall will be caught. When the inferior issues
3434 any of the specified syscalls, GDB will stop and announce the system
3435 call, both when it is called and when its call returns. This
3436 feature is currently available with a native GDB running on the
3437 Linux Kernel, under the following architectures: x86, x86_64,
3438 PowerPC and PowerPC64.
3440 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3442 Search memory for a sequence of bytes.
3444 maint set python print-stack
3445 maint show python print-stack
3446 Show a stack trace when an error is encountered in a Python script.
3449 Invoke CODE by passing it to the Python interpreter.
3454 These allow macros to be defined, undefined, and listed
3458 Show operating system information about processes.
3461 List the inferiors currently under GDB's control.
3464 Switch focus to inferior number NUM.
3467 Detach from inferior number NUM.
3470 Kill inferior number NUM.
3474 set spu stop-on-load
3475 show spu stop-on-load
3476 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3478 set spu auto-flush-cache
3479 show spu auto-flush-cache
3480 Control whether to automatically flush the software-managed cache
3481 during Cell/B.E. debugging.
3483 set sh calling-convention
3484 show sh calling-convention
3485 Control the calling convention used when calling SH target functions.
3488 show debug timestamp
3489 Control display of timestamps with GDB debugging output.
3491 set disassemble-next-line
3492 show disassemble-next-line
3493 Control display of disassembled source lines or instructions when
3496 set remote noack-packet
3497 show remote noack-packet
3498 Set/show the use of remote protocol QStartNoAckMode packet. See above
3499 under "New remote packets."
3501 set remote query-attached-packet
3502 show remote query-attached-packet
3503 Control use of remote protocol `qAttached' (query-attached) packet.
3505 set remote read-siginfo-object
3506 show remote read-siginfo-object
3507 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3510 set remote write-siginfo-object
3511 show remote write-siginfo-object
3512 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3515 set remote reverse-continue
3516 show remote reverse-continue
3517 Control use of remote protocol 'bc' (reverse-continue) packet.
3519 set remote reverse-step
3520 show remote reverse-step
3521 Control use of remote protocol 'bs' (reverse-step) packet.
3523 set displaced-stepping
3524 show displaced-stepping
3525 Control displaced stepping mode. Displaced stepping is a way to
3526 single-step over breakpoints without removing them from the debuggee.
3527 Also known as "out-of-line single-stepping".
3530 show debug displaced
3531 Control display of debugging info for displaced stepping.
3533 maint set internal-error
3534 maint show internal-error
3535 Control what GDB does when an internal error is detected.
3537 maint set internal-warning
3538 maint show internal-warning
3539 Control what GDB does when an internal warning is detected.
3544 Use a wrapper program to launch programs for debugging.
3546 set multiple-symbols (all|ask|cancel)
3547 show multiple-symbols
3548 The value of this variable can be changed to adjust the debugger behavior
3549 when an expression or a breakpoint location contains an ambiguous symbol
3550 name (an overloaded function name, for instance).
3552 set breakpoint always-inserted
3553 show breakpoint always-inserted
3554 Keep breakpoints always inserted in the target, as opposed to inserting
3555 them when resuming the target, and removing them when the target stops.
3556 This option can improve debugger performance on slow remote targets.
3558 set arm fallback-mode (arm|thumb|auto)
3559 show arm fallback-mode
3560 set arm force-mode (arm|thumb|auto)
3562 These commands control how ARM GDB determines whether instructions
3563 are ARM or Thumb. The default for both settings is auto, which uses
3564 the current CPSR value for instructions without symbols; previous
3565 versions of GDB behaved as if "set arm fallback-mode arm".
3567 set disable-randomization
3568 show disable-randomization
3569 Standalone programs run with the virtual address space randomization enabled
3570 by default on some platforms. This option keeps the addresses stable across
3571 multiple debugging sessions.
3575 Control whether other threads are stopped or not when some thread hits
3580 Requests that asynchronous execution is enabled in the target, if available.
3581 In this case, it's possible to resume target in the background, and interact
3582 with GDB while the target is running. "show target-async" displays the
3583 current state of asynchronous execution of the target.
3585 set target-wide-charset
3586 show target-wide-charset
3587 The target-wide-charset is the name of the character set that GDB
3588 uses when printing characters whose type is wchar_t.
3590 set tcp auto-retry (on|off)
3592 set tcp connect-timeout
3593 show tcp connect-timeout
3594 These commands allow GDB to retry failed TCP connections to a remote stub
3595 with a specified timeout period; this is useful if the stub is launched
3596 in parallel with GDB but may not be ready to accept connections immediately.
3598 set libthread-db-search-path
3599 show libthread-db-search-path
3600 Control list of directories which GDB will search for appropriate
3603 set schedule-multiple (on|off)
3604 show schedule-multiple
3605 Allow GDB to resume all threads of all processes or only threads of
3606 the current process.
3610 Use more aggressive caching for accesses to the stack. This improves
3611 performance of remote debugging (particularly backtraces) without
3612 affecting correctness.
3614 set interactive-mode (on|off|auto)
3615 show interactive-mode
3616 Control whether GDB runs in interactive mode (on) or not (off).
3617 When in interactive mode, GDB waits for the user to answer all
3618 queries. Otherwise, GDB does not wait and assumes the default
3619 answer. When set to auto (the default), GDB determines which
3620 mode to use based on the stdin settings.
3625 For program forks, this is replaced by the new more generic `info
3626 inferiors' command. To list checkpoints, you can still use the
3627 `info checkpoints' command, which was an alias for the `info forks'
3631 Replaced by the new `inferior' command. To switch between
3632 checkpoints, you can still use the `restart' command, which was an
3633 alias for the `fork' command.
3636 This is removed, since some targets don't have a notion of
3637 processes. To switch between processes, you can still use the
3638 `inferior' command using GDB's own inferior number.
3641 For program forks, this is replaced by the new more generic `kill
3642 inferior' command. To delete a checkpoint, you can still use the
3643 `delete checkpoint' command, which was an alias for the `delete
3647 For program forks, this is replaced by the new more generic `detach
3648 inferior' command. To detach a checkpoint, you can still use the
3649 `detach checkpoint' command, which was an alias for the `detach
3652 * New native configurations
3654 x86/x86_64 Darwin i[34567]86-*-darwin*
3656 x86_64 MinGW x86_64-*-mingw*
3660 Lattice Mico32 lm32-*
3661 x86 DICOS i[34567]86-*-dicos*
3662 x86_64 DICOS x86_64-*-dicos*
3665 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3666 (mingw32ce) debugging.
3672 These commands were actually not implemented on any target.
3674 *** Changes in GDB 6.8
3676 * New native configurations
3678 NetBSD/hppa hppa*-*netbsd*
3679 Xtensa GNU/Linux xtensa*-*-linux*
3683 NetBSD/hppa hppa*-*-netbsd*
3684 Xtensa GNU/Lunux xtensa*-*-linux*
3686 * Change in command line behavior -- corefiles vs. process ids.
3688 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3689 attaching to process NUMBER fails, GDB no longer attempts to open a
3690 core file named NUMBER. Attaching to a program using the -c option
3691 is no longer supported. Instead, use the '-p' or '--pid' options.
3693 * GDB can now be built as a native debugger for debugging Windows x86
3694 (mingw32) Portable Executable (PE) programs.
3696 * Pending breakpoints no longer change their number when their address
3699 * GDB now supports breakpoints with multiple locations,
3700 including breakpoints on C++ constructors, inside C++ templates,
3701 and in inlined functions.
3703 * GDB's ability to debug optimized code has been improved. GDB more
3704 accurately identifies function bodies and lexical blocks that occupy
3705 more than one contiguous range of addresses.
3707 * Target descriptions can now describe registers for PowerPC.
3709 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3710 registers on PowerPC targets.
3712 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3713 targets even when the libthread_db library is not available.
3715 * The GDB remote stub, gdbserver, now supports the new file transfer
3716 commands (remote put, remote get, and remote delete).
3718 * The GDB remote stub, gdbserver, now supports run and attach in
3719 extended-remote mode.
3721 * hppa*64*-*-hpux11* target broken
3722 The debugger is unable to start a program and fails with the following
3723 error: "Error trying to get information about dynamic linker".
3724 The gdb-6.7 release is also affected.
3726 * GDB now supports the --enable-targets= configure option to allow
3727 building a single GDB executable that supports multiple remote
3728 target architectures.
3730 * GDB now supports debugging C and C++ programs which use the
3731 Decimal Floating Point extension. In addition, the PowerPC target
3732 now has a set of pseudo-registers to inspect decimal float values
3733 stored in two consecutive float registers.
3735 * The -break-insert MI command can optionally create pending
3738 * Improved support for debugging Ada
3739 Many improvements to the Ada language support have been made. These
3741 - Better support for Ada2005 interface types
3742 - Improved handling of arrays and slices in general
3743 - Better support for Taft-amendment types
3744 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3746 - Improved command completion in Ada
3749 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3754 set print frame-arguments (all|scalars|none)
3755 show print frame-arguments
3756 The value of this variable can be changed to control which argument
3757 values should be printed by the debugger when displaying a frame.
3762 Transfer files to and from a remote target, and delete remote files.
3769 Transfer files to and from a remote target, and delete remote files.
3771 * New remote packets
3778 Open, close, read, write, and delete files on the remote system.
3781 Attach to an existing process on the remote system, in extended-remote
3785 Run a new process on the remote system, in extended-remote mode.
3787 *** Changes in GDB 6.7
3789 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3790 bfd, libiberty and opcodes, as revealed by static analysis donated by
3791 Coverity, Inc. (http://scan.coverity.com).
3793 * When looking up multiply-defined global symbols, GDB will now prefer the
3794 symbol definition in the current shared library if it was built using the
3795 -Bsymbolic linker option.
3797 * When the Text User Interface (TUI) is not configured, GDB will now
3798 recognize the -tui command-line option and print a message that the TUI
3801 * The GDB remote stub, gdbserver, now has lower overhead for high
3802 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3804 * GDB for MIPS targets now autodetects whether a remote target provides
3805 32-bit or 64-bit register values.
3807 * Support for C++ member pointers has been improved.
3809 * GDB now understands XML target descriptions, which specify the
3810 target's overall architecture. GDB can read a description from
3811 a local file or over the remote serial protocol.
3813 * Vectors of single-byte data use a new integer type which is not
3814 automatically displayed as character or string data.
3816 * The /s format now works with the print command. It displays
3817 arrays of single-byte integers and pointers to single-byte integers
3820 * Target descriptions can now describe target-specific registers,
3821 for architectures which have implemented the support (currently
3822 only ARM, M68K, and MIPS).
3824 * GDB and the GDB remote stub, gdbserver, now support the XScale
3827 * The GDB remote stub, gdbserver, has been updated to support
3828 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3829 has been rewritten to use the standard GDB remote protocol.
3831 * GDB can now step into C++ functions which are called through thunks.
3833 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3835 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3836 layout. It also supports a TextSeg= and DataSeg= response when only
3837 segment base addresses (rather than offsets) are available.
3839 * The /i format now outputs any trailing branch delay slot instructions
3840 immediately following the last instruction within the count specified.
3842 * The GDB remote protocol "T" stop reply packet now supports a
3843 "library" response. Combined with the new "qXfer:libraries:read"
3844 packet, this response allows GDB to debug shared libraries on targets
3845 where the operating system manages the list of loaded libraries (e.g.
3846 Windows and SymbianOS).
3848 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3849 (DLLs) on Windows and Windows CE targets.
3851 * GDB now supports a faster verification that a .debug file matches its binary
3852 according to its build-id signature, if the signature is present.
3858 Enable or disable hardware flow control (RTS/CTS) on the serial port
3859 when debugging using remote targets.
3861 set mem inaccessible-by-default
3862 show mem inaccessible-by-default
3863 If the target supplies a memory map, for instance via the remote
3864 protocol's "qXfer:memory-map:read" packet, setting this variable
3865 prevents GDB from accessing memory outside the memory map. This
3866 is useful for targets with memory mapped registers or which react
3867 badly to accesses of unmapped address space.
3869 set breakpoint auto-hw
3870 show breakpoint auto-hw
3871 If the target supplies a memory map, for instance via the remote
3872 protocol's "qXfer:memory-map:read" packet, setting this variable
3873 lets GDB use hardware breakpoints automatically for memory regions
3874 where it can not use software breakpoints. This covers both the
3875 "break" command and internal breakpoints used for other commands
3876 including "next" and "finish".
3879 catch exception unhandled
3880 Stop the program execution when Ada exceptions are raised.
3883 Stop the program execution when an Ada assertion failed.
3887 Set an alternate system root for target files. This is a more
3888 general version of "set solib-absolute-prefix", which is now
3889 an alias to "set sysroot".
3892 Provide extended SPU facility status information. This set of
3893 commands is available only when debugging the Cell/B.E. SPU
3896 * New native configurations
3898 OpenBSD/sh sh*-*openbsd*
3901 unset tdesc filename
3903 Use the specified local file as an XML target description, and do
3904 not query the target for its built-in description.
3908 OpenBSD/sh sh*-*-openbsd*
3909 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3910 Toshiba Media Processor mep-elf
3912 * New remote packets
3915 Ignore the specified signals; pass them directly to the debugged program
3916 without stopping other threads or reporting them to GDB.
3918 qXfer:features:read:
3919 Read an XML target description from the target, which describes its
3924 Read or write contents of an spufs file on the target system. These
3925 packets are available only on the Cell/B.E. SPU architecture.
3927 qXfer:libraries:read:
3928 Report the loaded shared libraries. Combined with new "T" packet
3929 response, this packet allows GDB to debug shared libraries on
3930 targets where the operating system manages the list of loaded
3931 libraries (e.g. Windows and SymbianOS).
3935 Support for these obsolete configurations has been removed.
3943 i[34567]86-*-lynxos*
3944 i[34567]86-*-netware*
3945 i[34567]86-*-sco3.2v5*
3946 i[34567]86-*-sco3.2v4*
3948 i[34567]86-*-sysv4.2*
3951 i[34567]86-*-unixware2*
3952 i[34567]86-*-unixware*
3961 * Other removed features
3968 Various m68k-only ROM monitors.
3975 Various Renesas ROM monitors and debugging interfaces for SH and
3980 Support for a Macraigor serial interface to on-chip debugging.
3981 GDB does not directly support the newer parallel or USB
3986 A debug information format. The predecessor to DWARF 2 and
3987 DWARF 3, which are still supported.
3989 Support for the HP aCC compiler on HP-UX/PA-RISC
3991 SOM-encapsulated symbolic debugging information, automatic
3992 invocation of pxdb, and the aCC custom C++ ABI. This does not
3993 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3994 with aCC can still be debugged on an assembly level.
3996 MIPS ".pdr" sections
3998 A MIPS-specific format used to describe stack frame layout
3999 in debugging information.
4003 GDB could work with an older version of Guile to debug
4004 the interpreter and Scheme programs running in it.
4006 set mips stack-arg-size
4007 set mips saved-gpreg-size
4009 Use "set mips abi" to control parameter passing for MIPS.
4011 *** Changes in GDB 6.6
4016 Cell Broadband Engine SPU spu-elf
4018 * GDB can now be configured as a cross-debugger targeting native Windows
4019 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4020 running on a Windows system over TCP/IP to debug Windows programs.
4022 * The GDB remote stub, gdbserver, has been updated to support Windows and
4023 Cygwin debugging. Both single-threaded and multi-threaded programs are
4026 * The "set trust-readonly-sections" command works again. This command was
4027 broken in GDB 6.3, 6.4, and 6.5.
4029 * The "load" command now supports writing to flash memory, if the remote
4030 stub provides the required support.
4032 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4033 longer requires symbolic debug information (e.g. DWARF-2).
4038 unset substitute-path
4039 show substitute-path
4040 Manage a list of substitution rules that GDB uses to rewrite the name
4041 of the directories where the sources are located. This can be useful
4042 for instance when the sources were moved to a different location
4043 between compilation and debugging.
4047 Print each CLI command as it is executed. Each command is prefixed with
4048 a number of `+' symbols representing the nesting depth.
4049 The source command now has a `-v' option to enable the same feature.
4053 The ARM Demon monitor support (RDP protocol, "target rdp").
4055 Kernel Object Display, an embedded debugging feature which only worked with
4056 an obsolete version of Cisco IOS.
4058 The 'set download-write-size' and 'show download-write-size' commands.
4060 * New remote packets
4063 Tell a stub about GDB client features, and request remote target features.
4064 The first feature implemented is PacketSize, which allows the target to
4065 specify the size of packets it can handle - to minimize the number of
4066 packets required and improve performance when connected to a remote
4070 Fetch an OS auxilliary vector from the remote stub. This packet is a
4071 more efficient replacement for qPart:auxv:read.
4073 qXfer:memory-map:read:
4074 Fetch a memory map from the remote stub, including information about
4075 RAM, ROM, and flash memory devices.
4080 Erase and program a flash memory device.
4082 * Removed remote packets
4085 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4086 used it, and only gdbserver implemented it.
4088 *** Changes in GDB 6.5
4092 Renesas M32C/M16C m32c-elf
4094 Morpho Technologies ms1 ms1-elf
4098 init-if-undefined Initialize a convenience variable, but
4099 only if it doesn't already have a value.
4101 The following commands are presently only implemented for native GNU/Linux:
4103 checkpoint Save a snapshot of the program state.
4105 restart <n> Return the program state to a
4106 previously saved state.
4108 info checkpoints List currently saved checkpoints.
4110 delete-checkpoint <n> Delete a previously saved checkpoint.
4112 set|show detach-on-fork Tell gdb whether to detach from a newly
4113 forked process, or to keep debugging it.
4115 info forks List forks of the user program that
4116 are available to be debugged.
4118 fork <n> Switch to debugging one of several
4119 forks of the user program that are
4120 available to be debugged.
4122 delete-fork <n> Delete a fork from the list of forks
4123 that are available to be debugged (and
4124 kill the forked process).
4126 detach-fork <n> Delete a fork from the list of forks
4127 that are available to be debugged (and
4128 allow the process to continue).
4132 Morpho Technologies ms2 ms1-elf
4134 * Improved Windows host support
4136 GDB now builds as a cross debugger hosted on i686-mingw32, including
4137 native console support, and remote communications using either
4138 network sockets or serial ports.
4140 * Improved Modula-2 language support
4142 GDB can now print most types in the Modula-2 syntax. This includes:
4143 basic types, set types, record types, enumerated types, range types,
4144 pointer types and ARRAY types. Procedure var parameters are correctly
4145 printed and hexadecimal addresses and character constants are also
4146 written in the Modula-2 syntax. Best results can be obtained by using
4147 GNU Modula-2 together with the -gdwarf-2 command line option.
4151 The ARM rdi-share module.
4153 The Netware NLM debug server.
4155 *** Changes in GDB 6.4
4157 * New native configurations
4159 OpenBSD/arm arm*-*-openbsd*
4160 OpenBSD/mips64 mips64-*-openbsd*
4164 Morpho Technologies ms1 ms1-elf
4166 * New command line options
4168 --batch-silent As for --batch, but totally silent.
4169 --return-child-result The debugger will exist with the same value
4170 the child (debugged) program exited with.
4171 --eval-command COMMAND, -ex COMMAND
4172 Execute a single GDB CLI command. This may be
4173 specified multiple times and in conjunction
4174 with the --command (-x) option.
4176 * Deprecated commands removed
4178 The following commands, that were deprecated in 2000, have been
4182 set|show arm disassembly-flavor set|show arm disassembler
4183 othernames set arm disassembler
4184 set|show remotedebug set|show debug remote
4185 set|show archdebug set|show debug arch
4186 set|show eventdebug set|show debug event
4189 * New BSD user-level threads support
4191 It is now possible to debug programs using the user-level threads
4192 library on OpenBSD and FreeBSD. Currently supported (target)
4195 FreeBSD/amd64 x86_64-*-freebsd*
4196 FreeBSD/i386 i386-*-freebsd*
4197 OpenBSD/i386 i386-*-openbsd*
4199 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4200 are not yet supported.
4202 * New support for Matsushita MN10300 w/sim added
4203 (Work in progress). mn10300-elf.
4205 * REMOVED configurations and files
4207 VxWorks and the XDR protocol *-*-vxworks
4208 Motorola MCORE mcore-*-*
4209 National Semiconductor NS32000 ns32k-*-*
4211 * New "set print array-indexes" command
4213 After turning this setting "on", GDB prints the index of each element
4214 when displaying arrays. The default is "off" to preserve the previous
4217 * VAX floating point support
4219 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4221 * User-defined command support
4223 In addition to using $arg0..$arg9 for argument passing, it is now possible
4224 to use $argc to determine now many arguments have been passed. See the
4225 section on user-defined commands in the user manual for more information.
4227 *** Changes in GDB 6.3:
4229 * New command line option
4231 GDB now accepts -l followed by a number to set the timeout for remote
4234 * GDB works with GCC -feliminate-dwarf2-dups
4236 GDB now supports a more compact representation of DWARF-2 debug
4237 information using DW_FORM_ref_addr references. These are produced
4238 by GCC with the option -feliminate-dwarf2-dups and also by some
4239 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4240 to use -feliminate-dwarf2-dups.
4242 * Internationalization
4244 When supported by the host system, GDB will be built with
4245 internationalization (libintl). The task of marking up the sources is
4246 continued, we're looking forward to our first translation.
4250 Initial support for debugging programs compiled with the GNAT
4251 implementation of the Ada programming language has been integrated
4252 into GDB. In this release, support is limited to expression evaluation.
4254 * New native configurations
4256 GNU/Linux/m32r m32r-*-linux-gnu
4260 GDB's remote protocol now includes support for the 'p' packet. This
4261 packet is used to fetch individual registers from a remote inferior.
4263 * END-OF-LIFE registers[] compatibility module
4265 GDB's internal register infrastructure has been completely rewritten.
4266 The new infrastructure making possible the implementation of key new
4267 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4270 GDB 6.3 will be the last release to include the the registers[]
4271 compatibility module that allowed out-of-date configurations to
4272 continue to work. This change directly impacts the following
4282 powerpc bdm protocol
4284 Unless there is activity to revive these configurations, they will be
4285 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4287 * OBSOLETE configurations and files
4289 Configurations that have been declared obsolete in this release have
4290 been commented out. Unless there is activity to revive these
4291 configurations, the next release of GDB will have their sources
4292 permanently REMOVED.
4301 *** Changes in GDB 6.2.1:
4303 * MIPS `break main; run' gave an heuristic-fence-post warning
4305 When attempting to run even a simple program, a warning about
4306 heuristic-fence-post being hit would be reported. This problem has
4309 * MIPS IRIX 'long double' crashed GDB
4311 When examining a long double variable, GDB would get a segmentation
4312 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4313 IRIX long double values).
4317 A bug in the VAX stack code was causing problems with the "next"
4318 command. This problem has been fixed.
4320 *** Changes in GDB 6.2:
4322 * Fix for ``many threads''
4324 On GNU/Linux systems that use the NPTL threads library, a program
4325 rapidly creating and deleting threads would confuse GDB leading to the
4328 ptrace: No such process.
4329 thread_db_get_info: cannot get thread info: generic error
4331 This problem has been fixed.
4333 * "-async" and "-noasync" options removed.
4335 Support for the broken "-noasync" option has been removed (it caused
4338 * New ``start'' command.
4340 This command runs the program until the begining of the main procedure.
4342 * New BSD Kernel Data Access Library (libkvm) interface
4344 Using ``target kvm'' it is now possible to debug kernel core dumps and
4345 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4346 platforms. Currently supported (native-only) configurations are:
4348 FreeBSD/amd64 x86_64-*-freebsd*
4349 FreeBSD/i386 i?86-*-freebsd*
4350 NetBSD/i386 i?86-*-netbsd*
4351 NetBSD/m68k m68*-*-netbsd*
4352 NetBSD/sparc sparc-*-netbsd*
4353 OpenBSD/amd64 x86_64-*-openbsd*
4354 OpenBSD/i386 i?86-*-openbsd*
4355 OpenBSD/m68k m68*-openbsd*
4356 OpenBSD/sparc sparc-*-openbsd*
4358 * Signal trampoline code overhauled
4360 Many generic problems with GDB's signal handling code have been fixed.
4361 These include: backtraces through non-contiguous stacks; recognition
4362 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4363 call; backtrace through a signal trampoline; step into and out of
4364 signal handlers; and single-stepping in the signal trampoline.
4366 Please note that kernel bugs are a limiting factor here. These
4367 features have been shown to work on an s390 GNU/Linux system that
4368 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4370 * Cygwin support for DWARF 2 added.
4372 * New native configurations
4374 GNU/Linux/hppa hppa*-*-linux*
4375 OpenBSD/hppa hppa*-*-openbsd*
4376 OpenBSD/m68k m68*-*-openbsd*
4377 OpenBSD/m88k m88*-*-openbsd*
4378 OpenBSD/powerpc powerpc-*-openbsd*
4379 NetBSD/vax vax-*-netbsd*
4380 OpenBSD/vax vax-*-openbsd*
4382 * END-OF-LIFE frame compatibility module
4384 GDB's internal frame infrastructure has been completely rewritten.
4385 The new infrastructure making it possible to support key new features
4386 including DWARF 2 Call Frame Information. To aid in the task of
4387 migrating old configurations to this new infrastructure, a
4388 compatibility module, that allowed old configurations to continue to
4389 work, was also included.
4391 GDB 6.2 will be the last release to include this frame compatibility
4392 module. This change directly impacts the following configurations:
4402 Unless there is activity to revive these configurations, they will be
4403 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4405 * REMOVED configurations and files
4407 Sun 3, running SunOS 3 m68*-*-sunos3*
4408 Sun 3, running SunOS 4 m68*-*-sunos4*
4409 Sun 2, running SunOS 3 m68000-*-sunos3*
4410 Sun 2, running SunOS 4 m68000-*-sunos4*
4411 Motorola 680x0 running LynxOS m68*-*-lynxos*
4412 AT&T 3b1/Unix pc m68*-att-*
4413 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4414 decstation mips-dec-* mips-little-*
4415 riscos mips-*-riscos* mips-*-sysv*
4416 sonymips mips-sony-*
4417 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4419 *** Changes in GDB 6.1.1:
4421 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4423 The TUI (Text-mode User Interface) is now built as part of a default
4424 GDB configuration. It is enabled by either selecting the TUI with the
4425 command line option "-i=tui" or by running the separate "gdbtui"
4426 program. For more information on the TUI, see the manual "Debugging
4429 * Pending breakpoint support (also included in GDB 6.1)
4431 Support has been added to allow you to specify breakpoints in shared
4432 libraries that have not yet been loaded. If a breakpoint location
4433 cannot be found, and the "breakpoint pending" option is set to auto,
4434 GDB queries you if you wish to make the breakpoint pending on a future
4435 shared-library load. If and when GDB resolves the breakpoint symbol,
4436 the pending breakpoint is removed as one or more regular breakpoints
4439 Pending breakpoints are very useful for GCJ Java debugging.
4441 * Fixed ISO-C build problems
4443 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4444 non ISO-C code that stopped them being built using a more strict ISO-C
4445 compiler (e.g., IBM's C compiler).
4447 * Fixed build problem on IRIX 5
4449 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4450 wasn't able to compile compile on an IRIX 5 system.
4452 * Added execute permission to gdb/gdbserver/configure
4454 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4455 permission. This bug would cause configure to fail on a number of
4456 systems (Solaris, IRIX). Ref: server/519.
4458 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4460 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4461 has been updated to use constant array sizes.
4463 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4465 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4466 its generated DWARF Call Frame Info. This encoding was causing GDB to
4467 panic, that panic has been fixed. Ref: gdb/1628.
4469 * Fixed a problem when examining parameters in shared library code.
4471 When examining parameters in optimized shared library code generated
4472 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4473 not available''. GDB now correctly displays the variable's value.
4475 *** Changes in GDB 6.1:
4477 * Removed --with-mmalloc
4479 Support for the mmalloc memory manager has been removed, as it
4480 conflicted with the internal gdb byte cache.
4482 * Changes in AMD64 configurations
4484 The AMD64 target now includes the %cs and %ss registers. As a result
4485 the AMD64 remote protocol has changed; this affects the floating-point
4486 and SSE registers. If you rely on those registers for your debugging,
4487 you should upgrade gdbserver on the remote side.
4489 * Revised SPARC target
4491 The SPARC target has been completely revised, incorporating the
4492 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4493 support for LynxOS and SunOS 4 has been dropped. Calling functions
4494 from within GDB on operating systems with a non-executable stack
4495 (Solaris, OpenBSD) now works.
4499 GDB has a new C++ demangler which does a better job on the mangled
4500 names generated by current versions of g++. It also runs faster, so
4501 with this and other changes gdb should now start faster on large C++
4504 * DWARF 2 Location Expressions
4506 GDB support for location expressions has been extended to support function
4507 arguments and frame bases. Older versions of GDB could crash when they
4510 * C++ nested types and namespaces
4512 GDB's support for nested types and namespaces in C++ has been
4513 improved, especially if you use the DWARF 2 debugging format. (This
4514 is the default for recent versions of GCC on most platforms.)
4515 Specifically, if you have a class "Inner" defined within a class or
4516 namespace "Outer", then GDB realizes that the class's name is
4517 "Outer::Inner", not simply "Inner". This should greatly reduce the
4518 frequency of complaints about not finding RTTI symbols. In addition,
4519 if you are stopped at inside of a function defined within a namespace,
4520 GDB modifies its name lookup accordingly.
4522 * New native configurations
4524 NetBSD/amd64 x86_64-*-netbsd*
4525 OpenBSD/amd64 x86_64-*-openbsd*
4526 OpenBSD/alpha alpha*-*-openbsd*
4527 OpenBSD/sparc sparc-*-openbsd*
4528 OpenBSD/sparc64 sparc64-*-openbsd*
4530 * New debugging protocols
4532 M32R with SDI protocol m32r-*-elf*
4534 * "set prompt-escape-char" command deleted.
4536 The command "set prompt-escape-char" has been deleted. This command,
4537 and its very obscure effet on GDB's prompt, was never documented,
4538 tested, nor mentioned in the NEWS file.
4540 * OBSOLETE configurations and files
4542 Configurations that have been declared obsolete in this release have
4543 been commented out. Unless there is activity to revive these
4544 configurations, the next release of GDB will have their sources
4545 permanently REMOVED.
4547 Sun 3, running SunOS 3 m68*-*-sunos3*
4548 Sun 3, running SunOS 4 m68*-*-sunos4*
4549 Sun 2, running SunOS 3 m68000-*-sunos3*
4550 Sun 2, running SunOS 4 m68000-*-sunos4*
4551 Motorola 680x0 running LynxOS m68*-*-lynxos*
4552 AT&T 3b1/Unix pc m68*-att-*
4553 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4554 decstation mips-dec-* mips-little-*
4555 riscos mips-*-riscos* mips-*-sysv*
4556 sonymips mips-sony-*
4557 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4559 * REMOVED configurations and files
4561 SGI Irix-4.x mips-sgi-irix4 or iris4
4562 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4563 Z8000 simulator z8k-zilog-none or z8ksim
4564 Matsushita MN10200 w/simulator mn10200-*-*
4565 H8/500 simulator h8500-hitachi-hms or h8500hms
4566 HP/PA running BSD hppa*-*-bsd*
4567 HP/PA running OSF/1 hppa*-*-osf*
4568 HP/PA Pro target hppa*-*-pro*
4569 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4570 386BSD i[3456]86-*-bsd*
4571 Sequent family i[3456]86-sequent-sysv4*
4572 i[3456]86-sequent-sysv*
4573 i[3456]86-sequent-bsd*
4574 SPARC running LynxOS sparc-*-lynxos*
4575 SPARC running SunOS 4 sparc-*-sunos4*
4576 Tsqware Sparclet sparclet-*-*
4577 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4579 *** Changes in GDB 6.0:
4583 Support for debugging the Objective-C programming language has been
4584 integrated into GDB.
4586 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4588 DWARF 2's Call Frame Information makes available compiler generated
4589 information that more exactly describes the program's run-time stack.
4590 By using this information, GDB is able to provide more robust stack
4593 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4594 have been updated to use a new backtrace mechanism which includes
4595 DWARF 2 CFI support.
4599 GDB's remote protocol has been extended to include support for hosted
4600 file I/O (where the remote target uses GDB's file system). See GDB's
4601 remote protocol documentation for details.
4603 * All targets using the new architecture framework.
4605 All of GDB's targets have been updated to use the new internal
4606 architecture framework. The way is now open for future GDB releases
4607 to include cross-architecture native debugging support (i386 on amd64,
4610 * GNU/Linux's Thread Local Storage (TLS)
4612 GDB now includes support for for the GNU/Linux implementation of
4613 per-thread variables.
4615 * GNU/Linux's Native POSIX Thread Library (NPTL)
4617 GDB's thread code has been updated to work with either the new
4618 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4620 * Separate debug info.
4622 GDB, in conjunction with BINUTILS, now supports a mechanism for
4623 automatically loading debug information from a separate file. Instead
4624 of shipping full debug and non-debug versions of system libraries,
4625 system integrators can now instead ship just the stripped libraries
4626 and optional debug files.
4628 * DWARF 2 Location Expressions
4630 DWARF 2 Location Expressions allow the compiler to more completely
4631 describe the location of variables (even in optimized code) to the
4634 GDB now includes preliminary support for location expressions (support
4635 for DW_OP_piece is still missing).
4639 A number of long standing bugs that caused GDB to die while starting a
4640 Java application have been fixed. GDB's Java support is now
4641 considered "useable".
4643 * GNU/Linux support for fork, vfork, and exec.
4645 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4646 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4649 * GDB supports logging output to a file
4651 There are two new commands, "set logging" and "show logging", which can be
4652 used to capture GDB's output to a file.
4654 * The meaning of "detach" has changed for gdbserver
4656 The "detach" command will now resume the application, as documented. To
4657 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4660 * d10v, m68hc11 `regs' command deprecated
4662 The `info registers' command has been updated so that it displays the
4663 registers using a format identical to the old `regs' command.
4667 A new command, "maint set profile on/off", has been added. This command can
4668 be used to enable or disable profiling while running GDB, to profile a
4669 session or a set of commands. In addition there is a new configure switch,
4670 "--enable-profiling", which will cause GDB to be compiled with profiling
4671 data, for more informative profiling results.
4673 * Default MI syntax changed to "mi2".
4675 The default MI (machine interface) syntax, enabled by the command line
4676 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4677 "mi1", can be enabled by specifying the option "-i=mi1".
4679 Support for the original "mi0" syntax (included in GDB 5.0) has been
4682 Fix for gdb/192: removed extraneous space when displaying frame level.
4683 Fix for gdb/672: update changelist is now output in mi list format.
4684 Fix for gdb/702: a -var-assign that updates the value now shows up
4685 in a subsequent -var-update.
4687 * New native configurations.
4689 FreeBSD/amd64 x86_64-*-freebsd*
4691 * Multi-arched targets.
4693 HP/PA HPUX11 hppa*-*-hpux*
4694 Renesas M32R/D w/simulator m32r-*-elf*
4696 * OBSOLETE configurations and files
4698 Configurations that have been declared obsolete in this release have
4699 been commented out. Unless there is activity to revive these
4700 configurations, the next release of GDB will have their sources
4701 permanently REMOVED.
4703 Z8000 simulator z8k-zilog-none or z8ksim
4704 Matsushita MN10200 w/simulator mn10200-*-*
4705 H8/500 simulator h8500-hitachi-hms or h8500hms
4706 HP/PA running BSD hppa*-*-bsd*
4707 HP/PA running OSF/1 hppa*-*-osf*
4708 HP/PA Pro target hppa*-*-pro*
4709 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4710 Sequent family i[3456]86-sequent-sysv4*
4711 i[3456]86-sequent-sysv*
4712 i[3456]86-sequent-bsd*
4713 Tsqware Sparclet sparclet-*-*
4714 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4716 * REMOVED configurations and files
4719 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4720 IBM AIX PS/2 i[3456]86-*-aix
4721 i386 running Mach 3.0 i[3456]86-*-mach3*
4722 i386 running Mach i[3456]86-*-mach*
4723 i386 running OSF/1 i[3456]86-*osf1mk*
4724 HP/Apollo 68k Family m68*-apollo*-sysv*,
4726 m68*-hp-bsd*, m68*-hp-hpux*
4727 Argonaut Risc Chip (ARC) arc-*-*
4728 Mitsubishi D30V d30v-*-*
4729 Fujitsu FR30 fr30-*-elf*
4730 OS/9000 i[34]86-*-os9k
4731 I960 with MON960 i960-*-coff
4733 * MIPS $fp behavior changed
4735 The convenience variable $fp, for the MIPS, now consistently returns
4736 the address of the current frame's base. Previously, depending on the
4737 context, $fp could refer to either $sp or the current frame's base
4738 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4739 The GNU Source-Level Debugger''.
4741 *** Changes in GDB 5.3:
4743 * GNU/Linux shared library multi-threaded performance improved.
4745 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4746 `/proc', in preference to `ptrace' for memory reads. This may result
4747 in an improvement in the start-up time of multi-threaded, shared
4748 library applications when run under GDB. One GDB user writes: ``loads
4749 shared libs like mad''.
4751 * ``gdbserver'' now supports multi-threaded applications on some targets
4753 Support for debugging multi-threaded applications which use
4754 the GNU/Linux LinuxThreads package has been added for
4755 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4756 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4758 * GDB now supports C/C++ preprocessor macros.
4760 GDB now expands preprocessor macro invocations in C/C++ expressions,
4761 and provides various commands for showing macro definitions and how
4764 The new command `macro expand EXPRESSION' expands any macro
4765 invocations in expression, and shows the result.
4767 The new command `show macro MACRO-NAME' shows the definition of the
4768 macro named MACRO-NAME, and where it was defined.
4770 Most compilers don't include information about macros in the debugging
4771 information by default. In GCC 3.1, for example, you need to compile
4772 your program with the options `-gdwarf-2 -g3'. If the macro
4773 information is present in the executable, GDB will read it.
4775 * Multi-arched targets.
4777 DEC Alpha (partial) alpha*-*-*
4778 DEC VAX (partial) vax-*-*
4780 National Semiconductor NS32000 (partial) ns32k-*-*
4781 Motorola 68000 (partial) m68k-*-*
4782 Motorola MCORE mcore-*-*
4786 Fujitsu FRV architecture added by Red Hat frv*-*-*
4789 * New native configurations
4791 Alpha NetBSD alpha*-*-netbsd*
4792 SH NetBSD sh*-*-netbsdelf*
4793 MIPS NetBSD mips*-*-netbsd*
4794 UltraSPARC NetBSD sparc64-*-netbsd*
4796 * OBSOLETE configurations and files
4798 Configurations that have been declared obsolete in this release have
4799 been commented out. Unless there is activity to revive these
4800 configurations, the next release of GDB will have their sources
4801 permanently REMOVED.
4803 Mitsubishi D30V d30v-*-*
4804 OS/9000 i[34]86-*-os9k
4805 IBM AIX PS/2 i[3456]86-*-aix
4806 Fujitsu FR30 fr30-*-elf*
4807 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4808 Argonaut Risc Chip (ARC) arc-*-*
4809 i386 running Mach 3.0 i[3456]86-*-mach3*
4810 i386 running Mach i[3456]86-*-mach*
4811 i386 running OSF/1 i[3456]86-*osf1mk*
4812 HP/Apollo 68k Family m68*-apollo*-sysv*,
4814 m68*-hp-bsd*, m68*-hp-hpux*
4815 I960 with MON960 i960-*-coff
4817 * OBSOLETE languages
4819 CHILL, a Pascal like language used by telecommunications companies.
4821 * REMOVED configurations and files
4823 AMD 29k family via UDI a29k-amd-udi, udi29k
4824 A29K VxWorks a29k-*-vxworks
4825 AMD 29000 embedded, using EBMON a29k-none-none
4826 AMD 29000 embedded with COFF a29k-none-coff
4827 AMD 29000 embedded with a.out a29k-none-aout
4829 testsuite/gdb.hp/gdb.threads-hp/ directory
4831 * New command "set max-user-call-depth <nnn>"
4833 This command allows the user to limit the call depth of user-defined
4834 commands. The default is 1024.
4836 * Changes in FreeBSD/i386 native debugging.
4838 Support for the "generate-core-file" has been added.
4840 * New commands "dump", "append", and "restore".
4842 These commands allow data to be copied from target memory
4843 to a bfd-format or binary file (dump and append), and back
4844 from a file into memory (restore).
4846 * Improved "next/step" support on multi-processor Alpha Tru64.
4848 The previous single-step mechanism could cause unpredictable problems,
4849 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4850 of a software single-step mechanism prevents this.
4852 *** Changes in GDB 5.2.1:
4860 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4861 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4862 Fix, by Joel Brobecker imported from mainline.
4864 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4865 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4866 Fix, by Fred Fish, imported from mainline.
4868 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4869 Surprisingly enough, it works now.
4870 By Michal Ludvig, imported from mainline.
4872 i386 hardware watchpoint support:
4873 avoid misses on second run for some targets.
4874 By Pierre Muller, imported from mainline.
4876 *** Changes in GDB 5.2:
4878 * New command "set trust-readonly-sections on[off]".
4880 This command is a hint that tells gdb that read-only sections
4881 really are read-only (ie. that their contents will not change).
4882 In this mode, gdb will go to the object file rather than the
4883 target to read memory from read-only sections (such as ".text").
4884 This can be a significant performance improvement on some
4885 (notably embedded) targets.
4887 * New command "generate-core-file" (or "gcore").
4889 This new gdb command allows the user to drop a core file of the child
4890 process state at any time. So far it's been implemented only for
4891 GNU/Linux and Solaris, but should be relatively easily ported to other
4892 hosts. Argument is core file name (defaults to core.<pid>).
4894 * New command line option
4896 GDB now accepts --pid or -p followed by a process id.
4898 * Change in command line behavior -- corefiles vs. process ids.
4900 There is a subtle behavior in the way in which GDB handles
4901 command line arguments. The first non-flag argument is always
4902 a program to debug, but the second non-flag argument may either
4903 be a corefile or a process id. Previously, GDB would attempt to
4904 open the second argument as a corefile, and if that failed, would
4905 issue a superfluous error message and then attempt to attach it as
4906 a process. Now, if the second argument begins with a non-digit,
4907 it will be treated as a corefile. If it begins with a digit,
4908 GDB will attempt to attach it as a process, and if no such process
4909 is found, will then attempt to open it as a corefile.
4911 * Changes in ARM configurations.
4913 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4914 configuration is fully multi-arch.
4916 * New native configurations
4918 ARM NetBSD arm*-*-netbsd*
4919 x86 OpenBSD i[3456]86-*-openbsd*
4920 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4921 Sparc64 running FreeBSD sparc64-*-freebsd*
4925 Sanyo XStormy16 xstormy16-elf
4927 * OBSOLETE configurations and files
4929 Configurations that have been declared obsolete in this release have
4930 been commented out. Unless there is activity to revive these
4931 configurations, the next release of GDB will have their sources
4932 permanently REMOVED.
4934 AMD 29k family via UDI a29k-amd-udi, udi29k
4935 A29K VxWorks a29k-*-vxworks
4936 AMD 29000 embedded, using EBMON a29k-none-none
4937 AMD 29000 embedded with COFF a29k-none-coff
4938 AMD 29000 embedded with a.out a29k-none-aout
4940 testsuite/gdb.hp/gdb.threads-hp/ directory
4942 * REMOVED configurations and files
4944 TI TMS320C80 tic80-*-*
4946 PowerPC Solaris powerpcle-*-solaris*
4947 PowerPC Windows NT powerpcle-*-cygwin32
4948 PowerPC Netware powerpc-*-netware*
4949 Harris/CXUX m88k m88*-harris-cxux*
4950 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4951 ns32k-utek-sysv* ns32k-utek-*
4952 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4953 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4954 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4955 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4956 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4958 * Changes to command line processing
4960 The new `--args' feature can be used to specify command-line arguments
4961 for the inferior from gdb's command line.
4963 * Changes to key bindings
4965 There is a new `operate-and-get-next' function bound to `C-o'.
4967 *** Changes in GDB 5.1.1
4969 Fix compile problem on DJGPP.
4971 Fix a problem with floating-point registers on the i386 being
4974 Fix to stop GDB crashing on .debug_str debug info.
4976 Numerous documentation fixes.
4978 Numerous testsuite fixes.
4980 *** Changes in GDB 5.1:
4982 * New native configurations
4984 Alpha FreeBSD alpha*-*-freebsd*
4985 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4986 MIPS GNU/Linux mips*-*-linux*
4987 MIPS SGI Irix 6.x mips*-sgi-irix6*
4988 ia64 AIX ia64-*-aix*
4989 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4993 Motorola 68HC11 and 68HC12 m68hc11-elf
4995 UltraSparc running GNU/Linux sparc64-*-linux*
4997 * OBSOLETE configurations and files
4999 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5000 Harris/CXUX m88k m88*-harris-cxux*
5001 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5002 ns32k-utek-sysv* ns32k-utek-*
5003 TI TMS320C80 tic80-*-*
5005 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5006 PowerPC Solaris powerpcle-*-solaris*
5007 PowerPC Windows NT powerpcle-*-cygwin32
5008 PowerPC Netware powerpc-*-netware*
5009 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5010 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5011 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5012 Apple Macintosh (MPW) host N/A
5014 stuff.c (Program to stuff files into a specially prepared space in kdb)
5015 kdb-start.c (Main loop for the standalone kernel debugger)
5017 Configurations that have been declared obsolete in this release have
5018 been commented out. Unless there is activity to revive these
5019 configurations, the next release of GDB will have their sources
5020 permanently REMOVED.
5022 * REMOVED configurations and files
5024 Altos 3068 m68*-altos-*
5025 Convex c1-*-*, c2-*-*
5027 ARM RISCix arm-*-* (as host)
5031 * GDB has been converted to ISO C.
5033 GDB's source code has been converted to ISO C. In particular, the
5034 sources are fully protoized, and rely on standard headers being
5039 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5041 * The MI enabled by default.
5043 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5044 revised and enabled by default. Packages which use GDB as a debugging
5045 engine behind a UI or another front end are encouraged to switch to
5046 using the GDB/MI interface, instead of the old annotations interface
5047 which is now deprecated.
5049 * Support for debugging Pascal programs.
5051 GDB now includes support for debugging Pascal programs. The following
5052 main features are supported:
5054 - Pascal-specific data types such as sets;
5056 - automatic recognition of Pascal sources based on file-name
5059 - Pascal-style display of data types, variables, and functions;
5061 - a Pascal expression parser.
5063 However, some important features are not yet supported.
5065 - Pascal string operations are not supported at all;
5067 - there are some problems with boolean types;
5069 - Pascal type hexadecimal constants are not supported
5070 because they conflict with the internal variables format;
5072 - support for Pascal objects and classes is not full yet;
5074 - unlike Pascal, GDB is case-sensitive for symbol names.
5076 * Changes in completion.
5078 Commands such as `shell', `run' and `set args', which pass arguments
5079 to inferior programs, now complete on file names, similar to what
5080 users expect at the shell prompt.
5082 Commands which accept locations, such as `disassemble', `print',
5083 `breakpoint', `until', etc. now complete on filenames as well as
5084 program symbols. Thus, if you type "break foob TAB", and the source
5085 files linked into the programs include `foobar.c', that file name will
5086 be one of the candidates for completion. However, file names are not
5087 considered for completion after you typed a colon that delimits a file
5088 name from a name of a function in that file, as in "break foo.c:bar".
5090 `set demangle-style' completes on available demangling styles.
5092 * New platform-independent commands:
5094 It is now possible to define a post-hook for a command as well as a
5095 hook that runs before the command. For more details, see the
5096 documentation of `hookpost' in the GDB manual.
5098 * Changes in GNU/Linux native debugging.
5100 Support for debugging multi-threaded programs has been completely
5101 revised for all platforms except m68k and sparc. You can now debug as
5102 many threads as your system allows you to have.
5104 Attach/detach is supported for multi-threaded programs.
5106 Support for SSE registers was added for x86. This doesn't work for
5107 multi-threaded programs though.
5109 * Changes in MIPS configurations.
5111 Multi-arch support is enabled for all MIPS configurations.
5113 GDB can now be built as native debugger on SGI Irix 6.x systems for
5114 debugging n32 executables. (Debugging 64-bit executables is not yet
5117 * Unified support for hardware watchpoints in all x86 configurations.
5119 Most (if not all) native x86 configurations support hardware-assisted
5120 breakpoints and watchpoints in a unified manner. This support
5121 implements debug register sharing between watchpoints, which allows to
5122 put a virtually infinite number of watchpoints on the same address,
5123 and also supports watching regions up to 16 bytes with several debug
5126 The new maintenance command `maintenance show-debug-regs' toggles
5127 debugging print-outs in functions that insert, remove, and test
5128 watchpoints and hardware breakpoints.
5130 * Changes in the DJGPP native configuration.
5132 New command ``info dos sysinfo'' displays assorted information about
5133 the CPU, OS, memory, and DPMI server.
5135 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5136 display information about segment descriptors stored in GDT, LDT, and
5139 New commands ``info dos pde'' and ``info dos pte'' display entries
5140 from Page Directory and Page Tables (for now works with CWSDPMI only).
5141 New command ``info dos address-pte'' displays the Page Table entry for
5142 a given linear address.
5144 GDB can now pass command lines longer than 126 characters to the
5145 program being debugged (requires an update to the libdbg.a library
5146 which is part of the DJGPP development kit).
5148 DWARF2 debug info is now supported.
5150 It is now possible to `step' and `next' through calls to `longjmp'.
5152 * Changes in documentation.
5154 All GDB documentation was converted to GFDL, the GNU Free
5155 Documentation License.
5157 Tracepoints-related commands are now fully documented in the GDB
5160 TUI, the Text-mode User Interface, is now documented in the manual.
5162 Tracepoints-related commands are now fully documented in the GDB
5165 The "GDB Internals" manual now has an index. It also includes
5166 documentation of `ui_out' functions, GDB coding standards, x86
5167 hardware watchpoints, and memory region attributes.
5169 * GDB's version number moved to ``version.in''
5171 The Makefile variable VERSION has been replaced by the file
5172 ``version.in''. People creating GDB distributions should update the
5173 contents of this file.
5177 GUD support is now a standard part of the EMACS distribution.
5179 *** Changes in GDB 5.0:
5181 * Improved support for debugging FP programs on x86 targets
5183 Unified and much-improved support for debugging floating-point
5184 programs on all x86 targets. In particular, ``info float'' now
5185 displays the FP registers in the same format on all x86 targets, with
5186 greater level of detail.
5188 * Improvements and bugfixes in hardware-assisted watchpoints
5190 It is now possible to watch array elements, struct members, and
5191 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5192 on x86 targets no longer erroneously trigger when the address is
5195 * Improvements in the native DJGPP version of GDB
5197 The distribution now includes all the scripts and auxiliary files
5198 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5199 machines ``out of the box''.
5201 The DJGPP version can now debug programs that use signals. It is
5202 possible to catch signals that happened in the debuggee, deliver
5203 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5204 would kill the program being debugged.) Programs that hook hardware
5205 interrupts (keyboard, timer, etc.) can also be debugged.
5207 It is now possible to debug DJGPP programs that redirect their
5208 standard handles or switch them to raw (as opposed to cooked) mode, or
5209 even close them. The command ``run < foo > bar'' works as expected,
5210 and ``info terminal'' reports useful information about the debuggee's
5211 terminal, including raw/cooked mode, redirection, etc.
5213 The DJGPP version now uses termios functions for console I/O, which
5214 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5217 DOS-style file names with drive letters are now fully supported by
5220 It is now possible to debug DJGPP programs that switch their working
5221 directory. It is also possible to rerun the debuggee any number of
5222 times without restarting GDB; thus, you can use the same setup,
5223 breakpoints, etc. for many debugging sessions.
5225 * New native configurations
5227 ARM GNU/Linux arm*-*-linux*
5228 PowerPC GNU/Linux powerpc-*-linux*
5232 Motorola MCore mcore-*-*
5233 x86 VxWorks i[3456]86-*-vxworks*
5234 PowerPC VxWorks powerpc-*-vxworks*
5235 TI TMS320C80 tic80-*-*
5237 * OBSOLETE configurations
5239 Altos 3068 m68*-altos-*
5240 Convex c1-*-*, c2-*-*
5242 ARM RISCix arm-*-* (as host)
5245 Configurations that have been declared obsolete will be commented out,
5246 but the code will be left in place. If there is no activity to revive
5247 these configurations before the next release of GDB, the sources will
5248 be permanently REMOVED.
5250 * Gould support removed
5252 Support for the Gould PowerNode and NP1 has been removed.
5254 * New features for SVR4
5256 On SVR4 native platforms (such as Solaris), if you attach to a process
5257 without first loading a symbol file, GDB will now attempt to locate and
5258 load symbols from the running process's executable file.
5260 * Many C++ enhancements
5262 C++ support has been greatly improved. Overload resolution now works properly
5263 in almost all cases. RTTI support is on the way.
5265 * Remote targets can connect to a sub-program
5267 A popen(3) style serial-device has been added. This device starts a
5268 sub-process (such as a stand-alone simulator) and then communicates
5269 with that. The sub-program to run is specified using the syntax
5270 ``|<program> <args>'' vis:
5272 (gdb) set remotedebug 1
5273 (gdb) target extended-remote |mn10300-elf-sim program-args
5275 * MIPS 64 remote protocol
5277 A long standing bug in the mips64 remote protocol where by GDB
5278 expected certain 32 bit registers (ex SR) to be transfered as 32
5279 instead of 64 bits has been fixed.
5281 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5282 added to provide backward compatibility with older versions of GDB.
5284 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5286 The command ``set remotebinarydownload'' command has been replaced by
5287 ``set remote X-packet''. Other commands in ``set remote'' family
5288 include ``set remote P-packet''.
5290 * Breakpoint commands accept ranges.
5292 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5293 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5294 ``tracepoint passcount'' also accepts a range of tracepoints.
5296 * ``apropos'' command added.
5298 The ``apropos'' command searches through command names and
5299 documentation strings, printing out matches, making it much easier to
5300 try to find a command that does what you are looking for.
5304 A new machine oriented interface (MI) has been added to GDB. This
5305 interface is designed for debug environments running GDB as a separate
5306 process. This is part of the long term libGDB project. See the
5307 "GDB/MI" chapter of the GDB manual for further information. It can be
5308 enabled by configuring with:
5310 .../configure --enable-gdbmi
5312 *** Changes in GDB-4.18:
5314 * New native configurations
5316 HP-UX 10.20 hppa*-*-hpux10.20
5317 HP-UX 11.x hppa*-*-hpux11.0*
5318 M68K GNU/Linux m68*-*-linux*
5322 Fujitsu FR30 fr30-*-elf*
5323 Intel StrongARM strongarm-*-*
5324 Mitsubishi D30V d30v-*-*
5326 * OBSOLETE configurations
5328 Gould PowerNode, NP1 np1-*-*, pn-*-*
5330 Configurations that have been declared obsolete will be commented out,
5331 but the code will be left in place. If there is no activity to revive
5332 these configurations before the next release of GDB, the sources will
5333 be permanently REMOVED.
5337 As a compatibility experiment, GDB's source files buildsym.h and
5338 buildsym.c have been converted to pure standard C, no longer
5339 containing any K&R compatibility code. We believe that all systems in
5340 use today either come with a standard C compiler, or have a GCC port
5341 available. If this is not true, please report the affected
5342 configuration to bug-gdb@gnu.org immediately. See the README file for
5343 information about getting a standard C compiler if you don't have one
5348 GDB now uses readline 2.2.
5350 * set extension-language
5352 You can now control the mapping between filename extensions and source
5353 languages by using the `set extension-language' command. For instance,
5354 you can ask GDB to treat .c files as C++ by saying
5355 set extension-language .c c++
5356 The command `info extensions' lists all of the recognized extensions
5357 and their associated languages.
5359 * Setting processor type for PowerPC and RS/6000
5361 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5362 you can use the `set processor' command to specify what variant of the
5363 PowerPC family you are debugging. The command
5367 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5368 following PowerPC and RS6000 variants:
5370 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5371 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5373 403GC IBM PowerPC 403GC
5374 505 Motorola PowerPC 505
5375 860 Motorola PowerPC 860 or 850
5376 601 Motorola PowerPC 601
5377 602 Motorola PowerPC 602
5378 603 Motorola/IBM PowerPC 603 or 603e
5379 604 Motorola PowerPC 604 or 604e
5380 750 Motorola/IBM PowerPC 750 or 750
5382 At the moment, this command just tells GDB what to name the
5383 special-purpose processor registers. Since almost all the affected
5384 registers are inaccessible to user-level programs, this command is
5385 only useful for remote debugging in its present form.
5389 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5390 more extensive support for HP-UX. Added features include shared
5391 library support, kernel threads and hardware watchpoints for 11.00,
5392 support for HP's ANSI C and C++ compilers, and a compatibility mode
5393 for xdb and dbx commands.
5397 HP's donation includes the new concept of catchpoints, which is a
5398 generalization of the old catch command. On HP-UX, it is now possible
5399 to catch exec, fork, and vfork, as well as library loading.
5401 This means that the existing catch command has changed; its first
5402 argument now specifies the type of catch to be set up. See the
5403 output of "help catch" for a list of catchpoint types.
5405 * Debugging across forks
5407 On HP-UX, you can choose which process to debug when a fork() happens
5412 HP has donated a curses-based terminal user interface (TUI). To get
5413 it, build with --enable-tui. Although this can be enabled for any
5414 configuration, at present it only works for native HP debugging.
5416 * GDB remote protocol additions
5418 A new protocol packet 'X' that writes binary data is now available.
5419 Default behavior is to try 'X', then drop back to 'M' if the stub
5420 fails to respond. The settable variable `remotebinarydownload'
5421 allows explicit control over the use of 'X'.
5423 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5424 full 64-bit address. The command
5426 set remoteaddresssize 32
5428 can be used to revert to the old behaviour. For existing remote stubs
5429 the change should not be noticed, as the additional address information
5432 In order to assist in debugging stubs, you may use the maintenance
5433 command `packet' to send any text string to the stub. For instance,
5435 maint packet heythere
5437 sends the packet "$heythere#<checksum>". Note that it is very easy to
5438 disrupt a debugging session by sending the wrong packet at the wrong
5441 The compare-sections command allows you to compare section data on the
5442 target to what is in the executable file without uploading or
5443 downloading, by comparing CRC checksums.
5445 * Tracing can collect general expressions
5447 You may now collect general expressions at tracepoints. This requires
5448 further additions to the target-side stub; see tracepoint.c and
5449 doc/agentexpr.texi for further details.
5451 * mask-address variable for Mips
5453 For Mips targets, you may control the zeroing of the upper 32 bits of
5454 a 64-bit address by entering `set mask-address on'. This is mainly
5455 of interest to users of embedded R4xxx and R5xxx processors.
5457 * Higher serial baud rates
5459 GDB's serial code now allows you to specify baud rates 57600, 115200,
5460 230400, and 460800 baud. (Note that your host system may not be able
5461 to achieve all of these rates.)
5465 The i960 configuration now includes an initial implementation of a
5466 builtin simulator, contributed by Jim Wilson.
5469 *** Changes in GDB-4.17:
5471 * New native configurations
5473 Alpha GNU/Linux alpha*-*-linux*
5474 Unixware 2.x i[3456]86-unixware2*
5475 Irix 6.x mips*-sgi-irix6*
5476 PowerPC GNU/Linux powerpc-*-linux*
5477 PowerPC Solaris powerpcle-*-solaris*
5478 Sparc GNU/Linux sparc-*-linux*
5479 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5483 Argonaut Risc Chip (ARC) arc-*-*
5484 Hitachi H8/300S h8300*-*-*
5485 Matsushita MN10200 w/simulator mn10200-*-*
5486 Matsushita MN10300 w/simulator mn10300-*-*
5487 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5488 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5489 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5490 Mitsubishi D10V w/simulator d10v-*-*
5491 Mitsubishi M32R/D w/simulator m32r-*-elf*
5492 Tsqware Sparclet sparclet-*-*
5493 NEC V850 w/simulator v850-*-*
5495 * New debugging protocols
5497 ARM with RDI protocol arm*-*-*
5498 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5499 DDB and LSI variants of PMON protocol mips*-*-*
5500 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5501 PowerPC with SDS protocol powerpc{,le}-*-eabi
5502 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5506 All configurations can now understand and use the DWARF 2 debugging
5507 format. The choice is automatic, if the symbol file contains DWARF 2
5512 GDB now includes basic Java language support. This support is
5513 only useful with Java compilers that produce native machine code.
5515 * solib-absolute-prefix and solib-search-path
5517 For SunOS and SVR4 shared libraries, you may now set the prefix for
5518 loading absolute shared library symbol files, and the search path for
5519 locating non-absolute shared library symbol files.
5521 * Live range splitting
5523 GDB can now effectively debug code for which GCC has performed live
5524 range splitting as part of its optimization. See gdb/doc/LRS for
5525 more details on the expected format of the stabs information.
5529 GDB's support for the GNU Hurd, including thread debugging, has been
5530 updated to work with current versions of the Hurd.
5534 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5535 instruction set. ARM GDB automatically detects when Thumb
5536 instructions are in use, and adjusts disassembly and backtracing
5541 GDB's MIPS target configurations now handle the MIP16 16-bit
5546 GDB now includes support for overlays; if an executable has been
5547 linked such that multiple sections are based at the same address, GDB
5548 will decide which section to use for symbolic info. You can choose to
5549 control the decision manually, using overlay commands, or implement
5550 additional target-side support and use "overlay load-target" to bring
5551 in the overlay mapping. Do "help overlay" for more detail.
5555 The command "info symbol <address>" displays information about
5556 the symbol at the specified address.
5560 The standard remote protocol now includes an extension that allows
5561 asynchronous collection and display of trace data. This requires
5562 extensive support in the target-side debugging stub. Tracing mode
5563 includes a new interaction mode in GDB and new commands: see the
5564 file tracepoint.c for more details.
5568 Configurations for embedded MIPS now include a simulator contributed
5569 by Cygnus Solutions. The simulator supports the instruction sets
5570 of most MIPS variants.
5574 Sparc configurations may now include the ERC32 simulator contributed
5575 by the European Space Agency. The simulator is not built into
5576 Sparc targets by default; configure with --enable-sim to include it.
5580 For target configurations that may include multiple variants of a
5581 basic architecture (such as MIPS and SH), you may now set the
5582 architecture explicitly. "set arch" sets, "info arch" lists
5583 the possible architectures.
5585 *** Changes in GDB-4.16:
5587 * New native configurations
5589 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5590 M68K NetBSD m68k-*-netbsd*
5591 PowerPC AIX 4.x powerpc-*-aix*
5592 PowerPC MacOS powerpc-*-macos*
5593 PowerPC Windows NT powerpcle-*-cygwin32
5594 RS/6000 AIX 4.x rs6000-*-aix4*
5598 ARM with RDP protocol arm-*-*
5599 I960 with MON960 i960-*-coff
5600 MIPS VxWorks mips*-*-vxworks*
5601 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5602 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5604 Matra Sparclet sparclet-*-*
5608 The powerpc-eabi configuration now includes the PSIM simulator,
5609 contributed by Andrew Cagney, with assistance from Mike Meissner.
5610 PSIM is a very elaborate model of the PowerPC, including not only
5611 basic instruction set execution, but also details of execution unit
5612 performance and I/O hardware. See sim/ppc/README for more details.
5616 GDB now works with Solaris 2.5.
5618 * Windows 95/NT native
5620 GDB will now work as a native debugger on Windows 95 and Windows NT.
5621 To build it from source, you must use the "gnu-win32" environment,
5622 which uses a DLL to emulate enough of Unix to run the GNU tools.
5623 Further information, binaries, and sources are available at
5624 ftp.cygnus.com, under pub/gnu-win32.
5626 * dont-repeat command
5628 If a user-defined command includes the command `dont-repeat', then the
5629 command will not be repeated if the user just types return. This is
5630 useful if the command is time-consuming to run, so that accidental
5631 extra keystrokes don't run the same command many times.
5633 * Send break instead of ^C
5635 The standard remote protocol now includes an option to send a break
5636 rather than a ^C to the target in order to interrupt it. By default,
5637 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5639 * Remote protocol timeout
5641 The standard remote protocol includes a new variable `remotetimeout'
5642 that allows you to set the number of seconds before GDB gives up trying
5643 to read from the target. The default value is 2.
5645 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5647 By default GDB will automatically keep track of objects as they are
5648 loaded and unloaded by the dynamic linker. By using the command `set
5649 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5650 when shared library events occur, thus allowing you to set breakpoints
5651 in shared libraries which are explicitly loaded by the inferior.
5653 Note this feature does not work on hpux8. On hpux9 you must link
5654 /usr/lib/end.o into your program. This feature should work
5655 automatically on hpux10.
5657 * Irix 5.x hardware watchpoint support
5659 Irix 5 configurations now support the use of hardware watchpoints.
5661 * Mips protocol "SYN garbage limit"
5663 When debugging a Mips target using the `target mips' protocol, you
5664 may set the number of characters that GDB will ignore by setting
5665 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5666 every character. The default value is 1050.
5668 * Recording and replaying remote debug sessions
5670 If you set `remotelogfile' to the name of a file, gdb will write to it
5671 a recording of a remote debug session. This recording may then be
5672 replayed back to gdb using "gdbreplay". See gdbserver/README for
5673 details. This is useful when you have a problem with GDB while doing
5674 remote debugging; you can make a recording of the session and send it
5675 to someone else, who can then recreate the problem.
5677 * Speedups for remote debugging
5679 GDB includes speedups for downloading and stepping MIPS systems using
5680 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5681 and more efficient S-record downloading.
5683 * Memory use reductions and statistics collection
5685 GDB now uses less memory and reports statistics about memory usage.
5686 Try the `maint print statistics' command, for example.
5688 *** Changes in GDB-4.15:
5690 * Psymtabs for XCOFF
5692 The symbol reader for AIX GDB now uses partial symbol tables. This
5693 can greatly improve startup time, especially for large executables.
5695 * Remote targets use caching
5697 Remote targets now use a data cache to speed up communication with the
5698 remote side. The data cache could lead to incorrect results because
5699 it doesn't know about volatile variables, thus making it impossible to
5700 debug targets which use memory mapped I/O devices. `set remotecache
5701 off' turns the the data cache off.
5703 * Remote targets may have threads
5705 The standard remote protocol now includes support for multiple threads
5706 in the target system, using new protocol commands 'H' and 'T'. See
5707 gdb/remote.c for details.
5711 If GDB is configured with `--enable-netrom', then it will include
5712 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5713 acts as though it is a bank of ROM on the target board, but you can
5714 write into it over the network. GDB's support consists only of
5715 support for fast loading into the emulated ROM; to debug, you must use
5716 another protocol, such as standard remote protocol. The usual
5717 sequence is something like
5719 target nrom <netrom-hostname>
5721 target remote <netrom-hostname>:1235
5725 GDB now includes support for the Apple Macintosh, as a host only. It
5726 may be run as either an MPW tool or as a standalone application, and
5727 it can debug through the serial port. All the usual GDB commands are
5728 available, but to the target command, you must supply "serial" as the
5729 device type instead of "/dev/ttyXX". See mpw-README in the main
5730 directory for more information on how to build. The MPW configuration
5731 scripts */mpw-config.in support only a few targets, and only the
5732 mips-idt-ecoff target has been tested.
5736 GDB configuration now uses autoconf. This is not user-visible,
5737 but does simplify configuration and building.
5741 GDB now supports hpux10.
5743 *** Changes in GDB-4.14:
5745 * New native configurations
5747 x86 FreeBSD i[345]86-*-freebsd
5748 x86 NetBSD i[345]86-*-netbsd
5749 NS32k NetBSD ns32k-*-netbsd
5750 Sparc NetBSD sparc-*-netbsd
5754 A29K VxWorks a29k-*-vxworks
5755 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5756 CPU32 EST-300 emulator m68*-*-est*
5757 PowerPC ELF powerpc-*-elf
5760 * Alpha OSF/1 support for procfs
5762 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5763 possible to attach to running processes. As the mounting of the /proc
5764 filesystem is optional on the Alpha, GDB automatically determines
5765 the availability of /proc during startup. This can lead to problems
5766 if /proc is unmounted after GDB has been started.
5768 * Arguments to user-defined commands
5770 User commands may accept up to 10 arguments separated by whitespace.
5771 Arguments are accessed within the user command via $arg0..$arg9. A
5774 print $arg0 + $arg1 + $arg2
5776 To execute the command use:
5779 Defines the command "adder" which prints the sum of its three arguments.
5780 Note the arguments are text substitutions, so they may reference variables,
5781 use complex expressions, or even perform inferior function calls.
5783 * New `if' and `while' commands
5785 This makes it possible to write more sophisticated user-defined
5786 commands. Both commands take a single argument, which is the
5787 expression to evaluate, and must be followed by the commands to
5788 execute, one per line, if the expression is nonzero, the list being
5789 terminated by the word `end'. The `if' command list may include an
5790 `else' word, which causes the following commands to be executed only
5791 if the expression is zero.
5793 * Fortran source language mode
5795 GDB now includes partial support for Fortran 77. It will recognize
5796 Fortran programs and can evaluate a subset of Fortran expressions, but
5797 variables and functions may not be handled correctly. GDB will work
5798 with G77, but does not yet know much about symbols emitted by other
5801 * Better HPUX support
5803 Most debugging facilities now work on dynamic executables for HPPAs
5804 running hpux9 or later. You can attach to running dynamically linked
5805 processes, but by default the dynamic libraries will be read-only, so
5806 for instance you won't be able to put breakpoints in them. To change
5807 that behavior do the following before running the program:
5813 This will cause the libraries to be mapped private and read-write.
5814 To revert to the normal behavior, do this:
5820 You cannot set breakpoints or examine data in the library until after
5821 the library is loaded if the function/data symbols do not have
5824 GDB can now also read debug symbols produced by the HP C compiler on
5825 HPPAs (sorry, no C++, Fortran or 68k support).
5827 * Target byte order now dynamically selectable
5829 You can choose which byte order to use with a target system, via the
5830 commands "set endian big" and "set endian little", and you can see the
5831 current setting by using "show endian". You can also give the command
5832 "set endian auto", in which case GDB will use the byte order
5833 associated with the executable. Currently, only embedded MIPS
5834 configurations support dynamic selection of target byte order.
5836 * New DOS host serial code
5838 This version uses DPMI interrupts to handle buffered I/O, so you
5839 no longer need to run asynctsr when debugging boards connected to
5842 *** Changes in GDB-4.13:
5844 * New "complete" command
5846 This lists all the possible completions for the rest of the line, if it
5847 were to be given as a command itself. This is intended for use by emacs.
5849 * Trailing space optional in prompt
5851 "set prompt" no longer adds a space for you after the prompt you set. This
5852 allows you to set a prompt which ends in a space or one that does not.
5854 * Breakpoint hit counts
5856 "info break" now displays a count of the number of times the breakpoint
5857 has been hit. This is especially useful in conjunction with "ignore"; you
5858 can ignore a large number of breakpoint hits, look at the breakpoint info
5859 to see how many times the breakpoint was hit, then run again, ignoring one
5860 less than that number, and this will get you quickly to the last hit of
5863 * Ability to stop printing at NULL character
5865 "set print null-stop" will cause GDB to stop printing the characters of
5866 an array when the first NULL is encountered. This is useful when large
5867 arrays actually contain only short strings.
5869 * Shared library breakpoints
5871 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5872 breakpoints in shared libraries before the executable is run.
5874 * Hardware watchpoints
5876 There is a new hardware breakpoint for the watch command for sparclite
5877 targets. See gdb/sparclite/hw_breakpoint.note.
5879 Hardware watchpoints are also now supported under GNU/Linux.
5883 Annotations have been added. These are for use with graphical interfaces,
5884 and are still experimental. Currently only gdba.el uses these.
5886 * Improved Irix 5 support
5888 GDB now works properly with Irix 5.2.
5890 * Improved HPPA support
5892 GDB now works properly with the latest GCC and GAS.
5894 * New native configurations
5896 Sequent PTX4 i[34]86-sequent-ptx4
5897 HPPA running OSF/1 hppa*-*-osf*
5898 Atari TT running SVR4 m68*-*-sysv4*
5899 RS/6000 LynxOS rs6000-*-lynxos*
5903 OS/9000 i[34]86-*-os9k
5904 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5907 * Hitachi SH7000 and E7000-PC ICE support
5909 There is now support for communicating with the Hitachi E7000-PC ICE.
5910 This is available automatically when GDB is configured for the SH.
5914 As usual, a variety of small fixes and improvements, both generic
5915 and configuration-specific. See the ChangeLog for more detail.
5917 *** Changes in GDB-4.12:
5919 * Irix 5 is now supported
5923 GDB-4.12 on the HPPA has a number of changes which make it unable
5924 to debug the output from the currently released versions of GCC and
5925 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5926 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5927 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5930 *** Changes in GDB-4.11:
5932 * User visible changes:
5936 The "set remotedebug" option is now consistent between the mips remote
5937 target, remote targets using the gdb-specific protocol, UDI (AMD's
5938 debug protocol for the 29k) and the 88k bug monitor. It is now an
5939 integer specifying a debug level (normally 0 or 1, but 2 means more
5940 debugging info for the mips target).
5942 * DEC Alpha native support
5944 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5945 debug info, but GDB works fairly well with the DEC compiler and should
5946 work with a future GCC release. See the README file for a few
5947 Alpha-specific notes.
5949 * Preliminary thread implementation
5951 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5953 * LynxOS native and target support for 386
5955 This release has been hosted on LynxOS 2.2, and also can be configured
5956 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5959 * Improvements in C++ mangling/demangling.
5961 This release has much better g++ debugging, specifically in name
5962 mangling/demangling, virtual function calls, print virtual table,
5963 call methods, ...etc.
5965 *** Changes in GDB-4.10:
5967 * User visible changes:
5969 Remote debugging using the GDB-specific (`target remote') protocol now
5970 supports the `load' command. This is only useful if you have some
5971 other way of getting the stub to the target system, and you can put it
5972 somewhere in memory where it won't get clobbered by the download.
5974 Filename completion now works.
5976 When run under emacs mode, the "info line" command now causes the
5977 arrow to point to the line specified. Also, "info line" prints
5978 addresses in symbolic form (as well as hex).
5980 All vxworks based targets now support a user settable option, called
5981 vxworks-timeout. This option represents the number of seconds gdb
5982 should wait for responses to rpc's. You might want to use this if
5983 your vxworks target is, perhaps, a slow software simulator or happens
5984 to be on the far side of a thin network line.
5988 This release contains support for using a DEC alpha as a GDB host for
5989 cross debugging. Native alpha debugging is not supported yet.
5992 *** Changes in GDB-4.9:
5996 This is the first GDB release which is accompanied by a matching testsuite.
5997 The testsuite requires installation of dejagnu, which should be available
5998 via ftp from most sites that carry GNU software.
6002 'Cfront' style demangling has had its name changed to 'ARM' style, to
6003 emphasize that it was written from the specifications in the C++ Annotated
6004 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6005 disclaimers, it still generated too much confusion with users attempting to
6006 use gdb with AT&T cfront.
6010 GDB now uses a standard remote interface to a simulator library.
6011 So far, the library contains simulators for the Zilog Z8001/2, the
6012 Hitachi H8/300, H8/500 and Super-H.
6014 * New targets supported
6016 H8/300 simulator h8300-hitachi-hms or h8300hms
6017 H8/500 simulator h8500-hitachi-hms or h8500hms
6018 SH simulator sh-hitachi-hms or sh
6019 Z8000 simulator z8k-zilog-none or z8ksim
6020 IDT MIPS board over serial line mips-idt-ecoff
6022 Cross-debugging to GO32 targets is supported. It requires a custom
6023 version of the i386-stub.c module which is integrated with the
6024 GO32 memory extender.
6026 * New remote protocols
6028 MIPS remote debugging protocol.
6030 * New source languages supported
6032 This version includes preliminary support for Chill, a Pascal like language
6033 used by telecommunications companies. Chill support is also being integrated
6034 into the GNU compiler, but we don't know when it will be publically available.
6037 *** Changes in GDB-4.8:
6039 * HP Precision Architecture supported
6041 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6042 version of this support was available as a set of patches from the
6043 University of Utah. GDB does not support debugging of programs
6044 compiled with the HP compiler, because HP will not document their file
6045 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6046 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6048 Many problems in the preliminary version have been fixed.
6050 * Faster and better demangling
6052 We have improved template demangling and fixed numerous bugs in the GNU style
6053 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6054 character types (wchar_t) are now supported. Demangling of each symbol is now
6055 only done once, and is cached when the symbol table for a file is read in.
6056 This results in a small increase in memory usage for C programs, a moderate
6057 increase in memory usage for C++ programs, and a fantastic speedup in
6060 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6061 from the specifications in the Annotated Reference Manual, which AT&T's
6062 compiler does not actually implement.
6064 * G++ multiple inheritance compiler problem
6066 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6067 inheritance lattices was reworked to properly discover ambiguities. We
6068 recently found an example which causes this new algorithm to fail in a
6069 very subtle way, producing bad debug information for those classes.
6070 The file 'gcc.patch' (in this directory) can be applied to gcc to
6071 circumvent the problem. A future GCC release will contain a complete
6074 The previous G++ debug info problem (mentioned below for the gdb-4.7
6075 release) is fixed in gcc version 2.3.2.
6077 * Improved configure script
6079 The `configure' script will now attempt to guess your system type if
6080 you don't supply a host system type. The old scheme of supplying a
6081 host system triplet is preferable over using this. All the magic is
6082 done in the new `config.guess' script. Examine it for details.
6084 We have also brought our configure script much more in line with the FSF's
6085 version. It now supports the --with-xxx options. In particular,
6086 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6087 The resulting GDB will not be able to read arbitrary object file formats --
6088 only the format ``expected'' to be used on the configured target system.
6089 We hope to make this the default in a future release.
6091 * Documentation improvements
6093 There's new internal documentation on how to modify GDB, and how to
6094 produce clean changes to the code. We implore people to read it
6095 before submitting changes.
6097 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6098 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6099 `info' files are also provided. To build `info' files from scratch,
6100 you will need the latest `makeinfo' release, which will be available in
6101 a future texinfo-X.Y release.
6103 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6104 We're not sure exactly which versions have this problem, but it has
6105 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6106 or better. If that isn't possible, there is a patch in
6107 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6108 around this problem.
6112 GDB now supports array constants that can be used in expressions typed in by
6113 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6114 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6117 The new directory `gdb/sparclite' contains a program that demonstrates
6118 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6120 * New native hosts supported
6122 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6123 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6125 * New targets supported
6127 AMD 29k family via UDI a29k-amd-udi or udi29k
6129 * New file formats supported
6131 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6132 HPUX core files, and SCO 3.2v2 core files.
6136 Attaching to processes now works again; thanks for the many bug reports.
6138 We have also stomped on a bunch of core dumps caused by
6139 printf_filtered("%s") problems.
6141 We eliminated a copyright problem on the rpc and ptrace header files
6142 for VxWorks, which was discovered at the last minute during the 4.7
6143 release. You should now be able to build a VxWorks GDB.
6145 You can now interrupt gdb while an attached process is running. This
6146 will cause the attached process to stop, and give control back to GDB.
6148 We fixed problems caused by using too many file descriptors
6149 for reading symbols from object files and libraries. This was
6150 especially a problem for programs that used many (~100) shared
6153 The `step' command now only enters a subroutine if there is line number
6154 information for the subroutine. Otherwise it acts like the `next'
6155 command. Previously, `step' would enter subroutines if there was
6156 any debugging information about the routine. This avoids problems
6157 when using `cc -g1' on MIPS machines.
6159 * Internal improvements
6161 GDB's internal interfaces have been improved to make it easier to support
6162 debugging of multiple languages in the future.
6164 GDB now uses a common structure for symbol information internally.
6165 Minimal symbols (derived from linkage symbols in object files), partial
6166 symbols (from a quick scan of debug information), and full symbols
6167 contain a common subset of information, making it easier to write
6168 shared code that handles any of them.
6170 * New command line options
6172 We now accept --silent as an alias for --quiet.
6176 The memory-mapped-malloc library is now licensed under the GNU Library
6177 General Public License.
6179 *** Changes in GDB-4.7:
6181 * Host/native/target split
6183 GDB has had some major internal surgery to untangle the support for
6184 hosts and remote targets. Now, when you configure GDB for a remote
6185 target, it will no longer load in all of the support for debugging
6186 local programs on the host. When fully completed and tested, this will
6187 ensure that arbitrary host/target combinations are possible.
6189 The primary conceptual shift is to separate the non-portable code in
6190 GDB into three categories. Host specific code is required any time GDB
6191 is compiled on that host, regardless of the target. Target specific
6192 code relates to the peculiarities of the target, but can be compiled on
6193 any host. Native specific code is everything else: it can only be
6194 built when the host and target are the same system. Child process
6195 handling and core file support are two common `native' examples.
6197 GDB's use of /proc for controlling Unix child processes is now cleaner.
6198 It has been split out into a single module under the `target_ops' vector,
6199 plus two native-dependent functions for each system that uses /proc.
6201 * New hosts supported
6203 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6204 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6205 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6207 * New targets supported
6209 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6210 68030 and CPU32 m68030-*-*, m68332-*-*
6212 * New native hosts supported
6214 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6215 (386bsd is not well tested yet)
6216 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6218 * New file formats supported
6220 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6221 supports reading of `a.out.adobe' object files, which are an a.out
6222 format extended with minimal information about multiple sections.
6226 `show copying' is the same as the old `info copying'.
6227 `show warranty' is the same as `info warrantee'.
6228 These were renamed for consistency. The old commands continue to work.
6230 `info handle' is a new alias for `info signals'.
6232 You can now define pre-command hooks, which attach arbitrary command
6233 scripts to any command. The commands in the hook will be executed
6234 prior to the user's command. You can also create a hook which will be
6235 executed whenever the program stops. See gdb.texinfo.
6239 We now deal with Cfront style name mangling, and can even extract type
6240 info from mangled symbols. GDB can automatically figure out which
6241 symbol mangling style your C++ compiler uses.
6243 Calling of methods and virtual functions has been improved as well.
6247 The crash that occured when debugging Sun Ansi-C compiled binaries is
6248 fixed. This was due to mishandling of the extra N_SO stabs output
6251 We also finally got Ultrix 4.2 running in house, and fixed core file
6252 support, with help from a dozen people on the net.
6254 John M. Farrell discovered that the reason that single-stepping was so
6255 slow on all of the Mips based platforms (primarily SGI and DEC) was
6256 that we were trying to demangle and lookup a symbol used for internal
6257 purposes on every instruction that was being stepped through. Changing
6258 the name of that symbol so that it couldn't be mistaken for a C++
6259 mangled symbol sped things up a great deal.
6261 Rich Pixley sped up symbol lookups in general by getting much smarter
6262 about when C++ symbol mangling is necessary. This should make symbol
6263 completion (TAB on the command line) much faster. It's not as fast as
6264 we'd like, but it's significantly faster than gdb-4.6.
6268 A new user controllable variable 'call_scratch_address' can
6269 specify the location of a scratch area to be used when GDB
6270 calls a function in the target. This is necessary because the
6271 usual method of putting the scratch area on the stack does not work
6272 in systems that have separate instruction and data spaces.
6274 We integrated changes to support the 29k UDI (Universal Debugger
6275 Interface), but discovered at the last minute that we didn't have all
6276 of the appropriate copyright paperwork. We are working with AMD to
6277 resolve this, and hope to have it available soon.
6281 We have sped up the remote serial line protocol, especially for targets
6282 with lots of registers. It now supports a new `expedited status' ('T')
6283 message which can be used in place of the existing 'S' status message.
6284 This allows the remote stub to send only the registers that GDB
6285 needs to make a quick decision about single-stepping or conditional
6286 breakpoints, eliminating the need to fetch the entire register set for
6287 each instruction being stepped through.
6289 The GDB remote serial protocol now implements a write-through cache for
6290 registers, only re-reading the registers if the target has run.
6292 There is also a new remote serial stub for SPARC processors. You can
6293 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6294 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6295 processor with a serial port.
6299 Configure.in files have become much easier to read and modify. A new
6300 `table driven' format makes it more obvious what configurations are
6301 supported, and what files each one uses.
6305 There is a new opcodes library which will eventually contain all of the
6306 disassembly routines and opcode tables. At present, it only contains
6307 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6308 disassembler (binutils/objdump) to share these routines.
6310 The libiberty library is now copylefted under the GNU Library General
6311 Public License. This allows more liberal use, and was done so libg++
6312 can use it. This makes no difference to GDB, since the Library License
6313 grants all the rights from the General Public License.
6317 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6318 reference to the stabs symbol info used by the debugger. It is (as far
6319 as we know) the only published document on this fascinating topic. We
6320 encourage you to read it, compare it to the stabs information on your
6321 system, and send improvements on the document in general (to
6322 bug-gdb@prep.ai.mit.edu).
6324 And, of course, many bugs have been fixed.
6327 *** Changes in GDB-4.6:
6329 * Better support for C++ function names
6331 GDB now accepts as input the "demangled form" of C++ overloaded function
6332 names and member function names, and can do command completion on such names
6333 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6334 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6335 Make use of command completion, it is your friend.
6337 GDB also now accepts a variety of C++ mangled symbol formats. They are
6338 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6339 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6340 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6341 for the list of formats.
6343 * G++ symbol mangling problem
6345 Recent versions of gcc have a bug in how they emit debugging information for
6346 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6347 directory) can be applied to gcc to fix the problem. Alternatively, if you
6348 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6349 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6350 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6353 * New 'maintenance' command
6355 All of the commands related to hacking GDB internals have been moved out of
6356 the main command set, and now live behind the 'maintenance' command. This
6357 can also be abbreviated as 'mt'. The following changes were made:
6359 dump-me -> maintenance dump-me
6360 info all-breakpoints -> maintenance info breakpoints
6361 printmsyms -> maintenance print msyms
6362 printobjfiles -> maintenance print objfiles
6363 printpsyms -> maintenance print psymbols
6364 printsyms -> maintenance print symbols
6366 The following commands are new:
6368 maintenance demangle Call internal GDB demangler routine to
6369 demangle a C++ link name and prints the result.
6370 maintenance print type Print a type chain for a given symbol
6372 * Change to .gdbinit file processing
6374 We now read the $HOME/.gdbinit file before processing the argv arguments
6375 (e.g. reading symbol files or core files). This allows global parameters to
6376 be set, which will apply during the symbol reading. The ./.gdbinit is still
6377 read after argv processing.
6379 * New hosts supported
6381 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6383 GNU/Linux support i386-unknown-linux or linux
6385 We are also including code to support the HP/PA running BSD and HPUX. This
6386 is almost guaranteed not to work, as we didn't have time to test or build it
6387 for this release. We are including it so that the more adventurous (or
6388 masochistic) of you can play with it. We also had major problems with the
6389 fact that the compiler that we got from HP doesn't support the -g option.
6392 * New targets supported
6394 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6396 * More smarts about finding #include files
6398 GDB now remembers the compilation directory for all include files, and for
6399 all files from which C is generated (like yacc and lex sources). This
6400 greatly improves GDB's ability to find yacc/lex sources, and include files,
6401 especially if you are debugging your program from a directory different from
6402 the one that contains your sources.
6404 We also fixed a bug which caused difficulty with listing and setting
6405 breakpoints in include files which contain C code. (In the past, you had to
6406 try twice in order to list an include file that you hadn't looked at before.)
6408 * Interesting infernals change
6410 GDB now deals with arbitrary numbers of sections, where the symbols for each
6411 section must be relocated relative to that section's landing place in the
6412 target's address space. This work was needed to support ELF with embedded
6413 stabs used by Solaris-2.0.
6415 * Bug fixes (of course!)
6417 There have been loads of fixes for the following things:
6418 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6419 i960, stabs, DOS(GO32), procfs, etc...
6421 See the ChangeLog for details.
6423 *** Changes in GDB-4.5:
6425 * New machines supported (host and target)
6427 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6429 SGI Irix-4.x mips-sgi-irix4 or iris4
6431 * New malloc package
6433 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6434 Mmalloc is capable of handling mutiple heaps of memory. It is also
6435 capable of saving a heap to a file, and then mapping it back in later.
6436 This can be used to greatly speedup the startup of GDB by using a
6437 pre-parsed symbol table which lives in a mmalloc managed heap. For
6438 more details, please read mmalloc/mmalloc.texi.
6442 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6443 'help info proc' for details.
6445 * MIPS ecoff symbol table format
6447 The code that reads MIPS symbol table format is now supported on all hosts.
6448 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6451 * File name changes for MS-DOS
6453 Many files in the config directories have been renamed to make it easier to
6454 support GDB on MS-DOSe systems (which have very restrictive file name
6455 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6456 environment) is close to working but has some remaining problems. Note
6457 that debugging of DOS programs is not supported, due to limitations
6458 in the ``operating system'', but it can be used to host cross-debugging.
6460 * Cross byte order fixes
6462 Many fixes have been made to support cross debugging of Sparc and MIPS
6463 targets from hosts whose byte order differs.
6465 * New -mapped and -readnow options
6467 If memory-mapped files are available on your system through the 'mmap'
6468 system call, you can use the -mapped option on the `file' or
6469 `symbol-file' commands to cause GDB to write the symbols from your
6470 program into a reusable file. If the program you are debugging is
6471 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6472 Future GDB debugging sessions will notice the presence of this file,
6473 and will quickly map in symbol information from it, rather than reading
6474 the symbol table from the executable program. Using the '-mapped'
6475 option in a GDB `file' or `symbol-file' command has the same effect as
6476 starting GDB with the '-mapped' command-line option.
6478 You can cause GDB to read the entire symbol table immediately by using
6479 the '-readnow' option with any of the commands that load symbol table
6480 information (or on the GDB command line). This makes the command
6481 slower, but makes future operations faster.
6483 The -mapped and -readnow options are typically combined in order to
6484 build a `fred.syms' file that contains complete symbol information.
6485 A simple GDB invocation to do nothing but build a `.syms' file for future
6488 gdb -batch -nx -mapped -readnow programname
6490 The `.syms' file is specific to the host machine on which GDB is run.
6491 It holds an exact image of GDB's internal symbol table. It cannot be
6492 shared across multiple host platforms.
6494 * longjmp() handling
6496 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6497 siglongjmp() without losing control. This feature has not yet been ported to
6498 all systems. It currently works on many 386 platforms, all MIPS-based
6499 platforms (SGI, DECstation, etc), and Sun3/4.
6503 Preliminary work has been put in to support the new Solaris OS from Sun. At
6504 this time, it can control and debug processes, but it is not capable of
6509 As always, many many bug fixes. The major areas were with g++, and mipsread.
6510 People using the MIPS-based platforms should experience fewer mysterious
6511 crashes and trashed symbol tables.
6513 *** Changes in GDB-4.4:
6515 * New machines supported (host and target)
6517 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6519 BSD Reno on Vax vax-dec-bsd
6520 Ultrix on Vax vax-dec-ultrix
6522 * New machines supported (target)
6524 AMD 29000 embedded, using EBMON a29k-none-none
6528 GDB continues to improve its handling of C++. `References' work better.
6529 The demangler has also been improved, and now deals with symbols mangled as
6530 per the Annotated C++ Reference Guide.
6532 GDB also now handles `stabs' symbol information embedded in MIPS
6533 `ecoff' symbol tables. Since the ecoff format was not easily
6534 extensible to handle new languages such as C++, this appeared to be a
6535 good way to put C++ debugging info into MIPS binaries. This option
6536 will be supported in the GNU C compiler, version 2, when it is
6539 * New features for SVR4
6541 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6542 shared libraries. Debugging dynamically linked programs should present
6543 only minor differences from debugging statically linked programs.
6545 The `info proc' command will print out information about any process
6546 on an SVR4 system (including the one you are debugging). At the moment,
6547 it prints the address mappings of the process.
6549 If you bring up GDB on another SVR4 system, please send mail to
6550 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6552 * Better dynamic linking support in SunOS
6554 Reading symbols from shared libraries which contain debugging symbols
6555 now works properly. However, there remain issues such as automatic
6556 skipping of `transfer vector' code during function calls, which
6557 make it harder to debug code in a shared library, than to debug the
6558 same code linked statically.
6562 GDB is now using the latest `getopt' routines from the FSF. This
6563 version accepts the -- prefix for options with long names. GDB will
6564 continue to accept the old forms (-option and +option) as well.
6565 Various single letter abbreviations for options have been explicity
6566 added to the option table so that they won't get overshadowed in the
6567 future by other options that begin with the same letter.
6571 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6572 Many assorted bugs have been handled. Many more remain to be handled.
6573 See the various ChangeLog files (primarily in gdb and bfd) for details.
6576 *** Changes in GDB-4.3:
6578 * New machines supported (host and target)
6580 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6581 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6582 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6584 * Almost SCO Unix support
6586 We had hoped to support:
6587 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6588 (except for core file support), but we discovered very late in the release
6589 that it has problems with process groups that render gdb unusable. Sorry
6590 about that. I encourage people to fix it and post the fixes.
6592 * Preliminary ELF and DWARF support
6594 GDB can read ELF object files on System V Release 4, and can handle
6595 debugging records for C, in DWARF format, in ELF files. This support
6596 is preliminary. If you bring up GDB on another SVR4 system, please
6597 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6602 GDB now uses the latest `readline' library. One user-visible change
6603 is that two tabs will list possible command completions, which previously
6604 required typing M-? (meta-question mark, or ESC ?).
6608 The `stepi' bug that many of you noticed has been squashed.
6609 Many bugs in C++ have been handled. Many more remain to be handled.
6610 See the various ChangeLog files (primarily in gdb and bfd) for details.
6612 * State of the MIPS world (in case you wondered):
6614 GDB can understand the symbol tables emitted by the compilers
6615 supplied by most vendors of MIPS-based machines, including DEC. These
6616 symbol tables are in a format that essentially nobody else uses.
6618 Some versions of gcc come with an assembler post-processor called
6619 mips-tfile. This program is required if you want to do source-level
6620 debugging of gcc-compiled programs. I believe FSF does not ship
6621 mips-tfile with gcc version 1, but it will eventually come with gcc
6624 Debugging of g++ output remains a problem. g++ version 1.xx does not
6625 really support it at all. (If you're lucky, you should be able to get
6626 line numbers and stack traces to work, but no parameters or local
6627 variables.) With some work it should be possible to improve the
6630 When gcc version 2 is released, you will have somewhat better luck.
6631 However, even then you will get confusing results for inheritance and
6634 We will eventually provide full debugging of g++ output on
6635 DECstations. This will probably involve some kind of stabs-in-ecoff
6636 encapulation, but the details have not been worked out yet.
6639 *** Changes in GDB-4.2:
6641 * Improved configuration
6643 Only one copy of `configure' exists now, and it is not self-modifying.
6644 Porting BFD is simpler.
6648 The `step' and `next' commands now only stop at the first instruction
6649 of a source line. This prevents the multiple stops that used to occur
6650 in switch statements, for-loops, etc. `Step' continues to stop if a
6651 function that has debugging information is called within the line.
6655 Lots of small bugs fixed. More remain.
6657 * New host supported (not target)
6659 Intel 386 PC clone running Mach i386-none-mach
6662 *** Changes in GDB-4.1:
6664 * Multiple source language support
6666 GDB now has internal scaffolding to handle several source languages.
6667 It determines the type of each source file from its filename extension,
6668 and will switch expression parsing and number formatting to match the
6669 language of the function in the currently selected stack frame.
6670 You can also specifically set the language to be used, with
6671 `set language c' or `set language modula-2'.
6675 GDB now has preliminary support for the GNU Modula-2 compiler,
6676 currently under development at the State University of New York at
6677 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6678 continue through the fall of 1991 and into 1992.
6680 Other Modula-2 compilers are currently not supported, and attempting to
6681 debug programs compiled with them will likely result in an error as the
6682 symbol table is read. Feel free to work on it, though!
6684 There are hooks in GDB for strict type checking and range checking,
6685 in the `Modula-2 philosophy', but they do not currently work.
6689 GDB can now write to executable and core files (e.g. patch
6690 a variable's value). You must turn this switch on, specify
6691 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6692 by assigning a new value to a variable. Modifications take
6695 * Automatic SunOS shared library reading
6697 When you run your program, GDB automatically determines where its
6698 shared libraries (if any) have been loaded, and reads their symbols.
6699 The `share' command is no longer needed. This also works when
6700 examining core files.
6704 You can specify the number of lines that the `list' command shows.
6707 * New machines supported (host and target)
6709 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6710 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6711 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6713 * New hosts supported (not targets)
6715 IBM RT/PC: romp-ibm-aix or rtpc
6717 * New targets supported (not hosts)
6719 AMD 29000 embedded with COFF a29k-none-coff
6720 AMD 29000 embedded with a.out a29k-none-aout
6721 Ultracomputer remote kernel debug a29k-nyu-kern
6723 * New remote interfaces
6729 *** Changes in GDB-4.0:
6733 Wide output is wrapped at good places to make the output more readable.
6735 Gdb now supports cross-debugging from a host machine of one type to a
6736 target machine of another type. Communication with the target system
6737 is over serial lines. The ``target'' command handles connecting to the
6738 remote system; the ``load'' command will download a program into the
6739 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6740 also supports debugging of realtime processes running under VxWorks,
6741 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6742 stub on the target system.
6744 New CPUs supported include the AMD 29000 and Intel 960.
6746 GDB now reads object files and symbol tables via a ``binary file''
6747 library, which allows a single copy of GDB to debug programs of multiple
6748 object file types such as a.out and coff.
6750 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6751 refcard.dvi and refcard.ps are available to format it).
6754 * Control-Variable user interface simplified
6756 All variables that control the operation of the debugger can be set
6757 by the ``set'' command, and displayed by the ``show'' command.
6759 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6760 ``Show prompt'' produces the response:
6761 Gdb's prompt is new-gdb=>.
6763 What follows are the NEW set commands. The command ``help set'' will
6764 print a complete list of old and new set commands. ``help set FOO''
6765 will give a longer description of the variable FOO. ``show'' will show
6766 all of the variable descriptions and their current settings.
6768 confirm on/off: Enables warning questions for operations that are
6769 hard to recover from, e.g. rerunning the program while
6770 it is already running. Default is ON.
6772 editing on/off: Enables EMACS style command line editing
6773 of input. Previous lines can be recalled with
6774 control-P, the current line can be edited with control-B,
6775 you can search for commands with control-R, etc.
6778 history filename NAME: NAME is where the gdb command history
6779 will be stored. The default is .gdb_history,
6780 or the value of the environment variable
6783 history size N: The size, in commands, of the command history. The
6784 default is 256, or the value of the environment variable
6787 history save on/off: If this value is set to ON, the history file will
6788 be saved after exiting gdb. If set to OFF, the
6789 file will not be saved. The default is OFF.
6791 history expansion on/off: If this value is set to ON, then csh-like
6792 history expansion will be performed on
6793 command line input. The default is OFF.
6795 radix N: Sets the default radix for input and output. It can be set
6796 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6797 in the current radix, so "set radix 10" is always a no-op.
6799 height N: This integer value is the number of lines on a page. Default
6800 is 24, the current `stty rows'' setting, or the ``li#''
6801 setting from the termcap entry matching the environment
6804 width N: This integer value is the number of characters on a line.
6805 Default is 80, the current `stty cols'' setting, or the ``co#''
6806 setting from the termcap entry matching the environment
6809 Note: ``set screensize'' is obsolete. Use ``set height'' and
6810 ``set width'' instead.
6812 print address on/off: Print memory addresses in various command displays,
6813 such as stack traces and structure values. Gdb looks
6814 more ``symbolic'' if you turn this off; it looks more
6815 ``machine level'' with it on. Default is ON.
6817 print array on/off: Prettyprint arrays. New convenient format! Default
6820 print demangle on/off: Print C++ symbols in "source" form if on,
6823 print asm-demangle on/off: Same, for assembler level printouts
6826 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6829 * Support for Epoch Environment.
6831 The epoch environment is a version of Emacs v18 with windowing. One
6832 new command, ``inspect'', is identical to ``print'', except that if you
6833 are running in the epoch environment, the value is printed in its own
6837 * Support for Shared Libraries
6839 GDB can now debug programs and core files that use SunOS shared libraries.
6840 Symbols from a shared library cannot be referenced
6841 before the shared library has been linked with the program (this
6842 happens after you type ``run'' and before the function main() is entered).
6843 At any time after this linking (including when examining core files
6844 from dynamically linked programs), gdb reads the symbols from each
6845 shared library when you type the ``sharedlibrary'' command.
6846 It can be abbreviated ``share''.
6848 sharedlibrary REGEXP: Load shared object library symbols for files
6849 matching a unix regular expression. No argument
6850 indicates to load symbols for all shared libraries.
6852 info sharedlibrary: Status of loaded shared libraries.
6857 A watchpoint stops execution of a program whenever the value of an
6858 expression changes. Checking for this slows down execution
6859 tremendously whenever you are in the scope of the expression, but is
6860 quite useful for catching tough ``bit-spreader'' or pointer misuse
6861 problems. Some machines such as the 386 have hardware for doing this
6862 more quickly, and future versions of gdb will use this hardware.
6864 watch EXP: Set a watchpoint (breakpoint) for an expression.
6866 info watchpoints: Information about your watchpoints.
6868 delete N: Deletes watchpoint number N (same as breakpoints).
6869 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6870 enable N: Re-enables watchpoint number N (same as breakpoints).
6873 * C++ multiple inheritance
6875 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6878 * C++ exception handling
6880 Gdb now supports limited C++ exception handling. Besides the existing
6881 ability to breakpoint on an exception handler, gdb can breakpoint on
6882 the raising of an exception (before the stack is peeled back to the
6885 catch FOO: If there is a FOO exception handler in the dynamic scope,
6886 set a breakpoint to catch exceptions which may be raised there.
6887 Multiple exceptions (``catch foo bar baz'') may be caught.
6889 info catch: Lists all exceptions which may be caught in the
6890 current stack frame.
6893 * Minor command changes
6895 The command ``call func (arg, arg, ...)'' now acts like the print
6896 command, except it does not print or save a value if the function's result
6897 is void. This is similar to dbx usage.
6899 The ``up'' and ``down'' commands now always print the frame they end up
6900 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6901 frames without printing.
6903 * New directory command
6905 'dir' now adds directories to the FRONT of the source search path.
6906 The path starts off empty. Source files that contain debug information
6907 about the directory in which they were compiled can be found even
6908 with an empty path; Sun CC and GCC include this information. If GDB can't
6909 find your source file in the current directory, type "dir .".
6911 * Configuring GDB for compilation
6913 For normal use, type ``./configure host''. See README or gdb.texinfo
6916 GDB now handles cross debugging. If you are remotely debugging between
6917 two different machines, type ``./configure host -target=targ''.
6918 Host is the machine where GDB will run; targ is the machine
6919 where the program that you are debugging will run.
projects / external / binutils.git / blob