1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The endianness used with the 'set endian auto' mode in the absence of
7 an executable selected for debugging is now the last endianness chosen
8 either by one of the 'set endian big' and 'set endian little' commands
9 or by inferring from the last executable used, rather than the startup
12 * The commands 'info variables/functions/types' now show the source line
13 numbers of symbol definitions when available.
15 * 'info proc' now works on running processes on FreeBSD systems and core
16 files created on FreeBSD systems.
18 * C expressions can now use _Alignof, and C++ expressions can now use
25 Control display of debugging info regarding the FreeBSD native target.
27 set|show varsize-limit
28 This new setting allows the user to control the maximum size of Ada
29 objects being printed when those objects have a variable type,
30 instead of that maximum size being hardcoded to 65536 bytes.
32 set|show record btrace cpu
33 Controls the processor to be used for enabling errata workarounds for
38 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
40 ** The commands attached to a breakpoint can be set by assigning to
41 the breakpoint's "commands" field.
43 ** gdb.execute can now execute multi-line gdb commands.
45 ** The new functions gdb.convenience_variable and
46 gdb.set_convenience_variable can be used to get and set the value
47 of convenience variables.
49 ** A gdb.Parameter will no longer print the "set" help text on an
50 ordinary "set"; instead by default a "set" will be silent unless
51 the get_set_string method returns a non-empty string.
55 RiscV ELF riscv*-*-elf
57 * Removed targets and native configurations
59 m88k running OpenBSD m88*-*-openbsd*
60 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
61 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
62 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
64 * Aarch64/Linux hardware watchpoints improvements
66 Hardware watchpoints on unaligned addresses are now properly
67 supported when running Linux kernel 4.10 or higher: read and access
68 watchpoints are no longer spuriously missed, and all watchpoints
69 lengths between 1 and 8 bytes are supported. On older kernels,
70 watchpoints set on unaligned addresses are no longer missed, with
71 the tradeoff that there is a possibility of false hits being
74 *** Changes in GDB 8.1
76 * GDB now supports dynamically creating arbitrary register groups specified
77 in XML target descriptions. This allows for finer grain grouping of
78 registers on systems with a large amount of registers.
80 * The 'ptype' command now accepts a '/o' flag, which prints the
81 offsets and sizes of fields in a struct, like the pahole(1) tool.
83 * New "--readnever" command line option instructs GDB to not read each
84 symbol file's symbolic debug information. This makes startup faster
85 but at the expense of not being able to perform symbolic debugging.
86 This option is intended for use cases where symbolic debugging will
87 not be used, e.g., when you only need to dump the debuggee's core.
89 * GDB now uses the GNU MPFR library, if available, to emulate target
90 floating-point arithmetic during expression evaluation when the target
91 uses different floating-point formats than the host. At least version
92 3.1 of GNU MPFR is required.
94 * GDB now supports access to the guarded-storage-control registers and the
95 software-based guarded-storage broadcast control registers on IBM z14.
97 * On Unix systems, GDB now supports transmitting environment variables
98 that are to be set or unset to GDBserver. These variables will
99 affect the environment to be passed to the remote inferior.
101 To inform GDB of environment variables that are to be transmitted to
102 GDBserver, use the "set environment" command. Only user set
103 environment variables are sent to GDBserver.
105 To inform GDB of environment variables that are to be unset before
106 the remote inferior is started by the GDBserver, use the "unset
107 environment" command.
109 * Completion improvements
111 ** GDB can now complete function parameters in linespecs and
112 explicit locations without quoting. When setting breakpoints,
113 quoting around functions names to help with TAB-completion is
114 generally no longer necessary. For example, this now completes
117 (gdb) b function(in[TAB]
118 (gdb) b function(int)
120 Related, GDB is no longer confused with completing functions in
121 C++ anonymous namespaces:
124 (gdb) b (anonymous namespace)::[TAB][TAB]
125 (anonymous namespace)::a_function()
126 (anonymous namespace)::b_function()
128 ** GDB now has much improved linespec and explicit locations TAB
129 completion support, that better understands what you're
130 completing and offers better suggestions. For example, GDB no
131 longer offers data symbols as possible completions when you're
132 setting a breakpoint.
134 ** GDB now TAB-completes label symbol names.
136 ** The "complete" command now mimics TAB completion accurately.
138 * New command line options (gcore)
141 Dump all memory mappings.
143 * Breakpoints on C++ functions are now set on all scopes by default
145 By default, breakpoints on functions/methods are now interpreted as
146 specifying all functions with the given name ignoring missing
147 leading scopes (namespaces and classes).
149 For example, assuming a C++ program with symbols named:
154 both commands "break func()" and "break B::func()" set a breakpoint
157 You can use the new flag "-qualified" to override this. This makes
158 GDB interpret the specified function name as a complete
159 fully-qualified name instead. For example, using the same C++
160 program, the "break -q B::func" command sets a breakpoint on
161 "B::func", only. A parameter has been added to the Python
162 gdb.Breakpoint constructor to achieve the same result when creating
163 a breakpoint from Python.
165 * Breakpoints on functions marked with C++ ABI tags
167 GDB can now set breakpoints on functions marked with C++ ABI tags
168 (e.g., [abi:cxx11]). See here for a description of ABI tags:
169 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
171 Functions with a C++11 abi tag are demangled/displayed like this:
173 function[abi:cxx11](int)
176 You can now set a breakpoint on such functions simply as if they had
179 (gdb) b function(int)
181 Or if you need to disambiguate between tags, like:
183 (gdb) b function[abi:other_tag](int)
185 Tab completion was adjusted accordingly as well.
189 ** New events gdb.new_inferior, gdb.inferior_deleted, and
190 gdb.new_thread are emitted. See the manual for further
191 description of these.
193 ** A new function, "gdb.rbreak" has been added to the Python API.
194 This function allows the setting of a large number of breakpoints
195 via a regex pattern in Python. See the manual for further details.
197 ** Python breakpoints can now accept explicit locations. See the
198 manual for a further description of this feature.
201 * New features in the GDB remote stub, GDBserver
203 ** GDBserver is now able to start inferior processes with a
204 specified initial working directory.
206 The user can set the desired working directory to be used from
207 GDB using the new "set cwd" command.
209 ** New "--selftest" command line option runs some GDBserver self
210 tests. These self tests are disabled in releases.
212 ** On Unix systems, GDBserver now does globbing expansion and variable
213 substitution in inferior command line arguments.
215 This is done by starting inferiors using a shell, like GDB does.
216 See "set startup-with-shell" in the user manual for how to disable
217 this from GDB when using "target extended-remote". When using
218 "target remote", you can disable the startup with shell by using the
219 new "--no-startup-with-shell" GDBserver command line option.
221 ** On Unix systems, GDBserver now supports receiving environment
222 variables that are to be set or unset from GDB. These variables
223 will affect the environment to be passed to the inferior.
225 * When catching an Ada exception raised with a message, GDB now prints
226 the message in the catchpoint hit notification. In GDB/MI mode, that
227 information is provided as an extra field named "exception-message"
228 in the *stopped notification.
230 * Trait objects can now be inspected When debugging Rust code. This
231 requires compiler support which will appear in Rust 1.24.
235 QEnvironmentHexEncoded
236 Inform GDBserver of an environment variable that is to be passed to
237 the inferior when starting it.
240 Inform GDBserver of an environment variable that is to be unset
241 before starting the remote inferior.
244 Inform GDBserver that the environment should be reset (i.e.,
245 user-set environment variables should be unset).
248 Indicates whether the inferior must be started with a shell or not.
251 Tell GDBserver that the inferior to be started should use a specific
254 * The "maintenance print c-tdesc" command now takes an optional
255 argument which is the file name of XML target description.
257 * The "maintenance selftest" command now takes an optional argument to
258 filter the tests to be run.
260 * The "enable", and "disable" commands now accept a range of
261 breakpoint locations, e.g. "enable 1.3-5".
266 Set and show the current working directory for the inferior.
269 Set and show compilation command used for compiling and injecting code
270 with the 'compile' commands.
272 set debug separate-debug-file
273 show debug separate-debug-file
274 Control the display of debug output about separate debug file search.
276 set dump-excluded-mappings
277 show dump-excluded-mappings
278 Control whether mappings marked with the VM_DONTDUMP flag should be
279 dumped when generating a core file.
282 List the registered selftests.
285 Start the debugged program stopping at the first instruction.
288 Control display of debugging messages related to OpenRISC targets.
290 set|show print type nested-type-limit
291 Set and show the limit of nesting level for nested types that the
292 type printer will show.
294 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
297 * Safer/improved support for debugging with no debug info
299 GDB no longer assumes functions with no debug information return
302 This means that GDB now refuses to call such functions unless you
303 tell it the function's type, by either casting the call to the
304 declared return type, or by casting the function to a function
305 pointer of the right type, and calling that:
307 (gdb) p getenv ("PATH")
308 'getenv' has unknown return type; cast the call to its declared return type
309 (gdb) p (char *) getenv ("PATH")
310 $1 = 0x7fffffffe "/usr/local/bin:/"...
311 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
312 $2 = 0x7fffffffe "/usr/local/bin:/"...
314 Similarly, GDB no longer assumes that global variables with no debug
315 info have type 'int', and refuses to print the variable's value
316 unless you tell it the variable's type:
319 'var' has unknown type; cast it to its declared type
323 * New native configurations
325 FreeBSD/aarch64 aarch64*-*-freebsd*
326 FreeBSD/arm arm*-*-freebsd*
330 FreeBSD/aarch64 aarch64*-*-freebsd*
331 FreeBSD/arm arm*-*-freebsd*
332 OpenRISC ELF or1k*-*-elf
334 * Removed targets and native configurations
336 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
338 *** Changes in GDB 8.0
340 * GDB now supports access to the PKU register on GNU/Linux. The register is
341 added by the Memory Protection Keys for Userspace feature which will be
342 available in future Intel CPUs.
344 * GDB now supports C++11 rvalue references.
348 ** New functions to start, stop and access a running btrace recording.
349 ** Rvalue references are now supported in gdb.Type.
351 * GDB now supports recording and replaying rdrand and rdseed Intel 64
354 * Building GDB and GDBserver now requires a C++11 compiler.
356 For example, GCC 4.8 or later.
358 It is no longer possible to build GDB or GDBserver with a C
359 compiler. The --disable-build-with-cxx configure option has been
362 * Building GDB and GDBserver now requires GNU make >= 3.81.
364 It is no longer supported to build GDB or GDBserver with another
365 implementation of the make program or an earlier version of GNU make.
367 * Native debugging on MS-Windows supports command-line redirection
369 Command-line arguments used for starting programs on MS-Windows can
370 now include redirection symbols supported by native Windows shells,
371 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
372 as "run", "start", and "set args", as well as the corresponding MI
375 * Support for thread names on MS-Windows.
377 GDB now catches and handles the special exception that programs
378 running on MS-Windows use to assign names to threads in the
381 * Support for Java programs compiled with gcj has been removed.
383 * User commands now accept an unlimited number of arguments.
384 Previously, only up to 10 was accepted.
386 * The "eval" command now expands user-defined command arguments.
388 This makes it easier to process a variable number of arguments:
393 eval "print $arg%d", $i
398 * Target descriptions can now describe registers for sparc32 and sparc64.
400 * GDB now supports DWARF version 5 (debug information format).
401 Its .debug_names index is not yet supported.
403 * New native configurations
405 FreeBSD/mips mips*-*-freebsd
409 Synopsys ARC arc*-*-elf32
410 FreeBSD/mips mips*-*-freebsd
412 * Removed targets and native configurations
414 Alpha running FreeBSD alpha*-*-freebsd*
415 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
420 Erases all the flash memory regions reported by the target.
422 maint print arc arc-instruction address
423 Print internal disassembler information about instruction at a given address.
427 set disassembler-options
428 show disassembler-options
429 Controls the passing of target specific information to the disassembler.
430 If it is necessary to specify more than one disassembler option then
431 multiple options can be placed together into a comma separated list.
432 The default value is the empty string. Currently, the only supported
433 targets are ARM, PowerPC and S/390.
438 Erases all the flash memory regions reported by the target. This is
439 equivalent to the CLI command flash-erase.
441 -file-list-shared-libraries
442 List the shared libraries in the program. This is
443 equivalent to the CLI command "info shared".
446 Catchpoints stopping the program when Ada exceptions are
447 handled. This is equivalent to the CLI command "catch handlers".
449 *** Changes in GDB 7.12
451 * GDB and GDBserver now build with a C++ compiler by default.
453 The --enable-build-with-cxx configure option is now enabled by
454 default. One must now explicitly configure with
455 --disable-build-with-cxx in order to build with a C compiler. This
456 option will be removed in a future release.
458 * GDBserver now supports recording btrace without maintaining an active
461 * GDB now supports a negative repeat count in the 'x' command to examine
462 memory backward from the given address. For example:
465 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
466 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
467 (gdb) x/-5i 0x0000000000400580
468 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
469 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
470 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
471 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
472 0x40057b <main(int, char**)+25>:
473 callq 0x400536 <Func1(int, char const*)>
475 * Fortran: Support structures with fields of dynamic types and
476 arrays of dynamic types.
478 * The symbol dumping maintenance commands have new syntax.
479 maint print symbols [-pc address] [--] [filename]
480 maint print symbols [-objfile objfile] [-source source] [--] [filename]
481 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
482 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
483 maint print msymbols [-objfile objfile] [--] [filename]
485 * GDB now supports multibit bitfields and enums in target register
488 * New Python-based convenience function $_as_string(val), which returns
489 the textual representation of a value. This function is especially
490 useful to obtain the text label of an enum value.
492 * Intel MPX bound violation handling.
494 Segmentation faults caused by a Intel MPX boundary violation
495 now display the kind of violation (upper or lower), the memory
496 address accessed and the memory bounds, along with the usual
497 signal received and code location.
501 Program received signal SIGSEGV, Segmentation fault
502 Upper bound violation while accessing address 0x7fffffffc3b3
503 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
504 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
506 * Rust language support.
507 GDB now supports debugging programs written in the Rust programming
508 language. See https://www.rust-lang.org/ for more information about
511 * Support for running interpreters on specified input/output devices
513 GDB now supports a new mechanism that allows frontends to provide
514 fully featured GDB console views, as a better alternative to
515 building such views on top of the "-interpreter-exec console"
516 command. See the new "new-ui" command below. With that command,
517 frontends can now start GDB in the traditional command-line mode
518 running in an embedded terminal emulator widget, and create a
519 separate MI interpreter running on a specified i/o device. In this
520 way, GDB handles line editing, history, tab completion, etc. in the
521 console all by itself, and the GUI uses the separate MI interpreter
522 for its own control and synchronization, invisible to the command
525 * The "catch syscall" command catches groups of related syscalls.
527 The "catch syscall" command now supports catching a group of related
528 syscalls using the 'group:' or 'g:' prefix.
533 skip -gfile file-glob-pattern
534 skip -function function
535 skip -rfunction regular-expression
536 A generalized form of the skip command, with new support for
537 glob-style file names and regular expressions for function names.
538 Additionally, a file spec and a function spec may now be combined.
540 maint info line-table REGEXP
541 Display the contents of GDB's internal line table data struture.
544 Run any GDB unit tests that were compiled in.
547 Start a new user interface instance running INTERP as interpreter,
548 using the TTY file for input/output.
552 ** gdb.Breakpoint objects have a new attribute "pending", which
553 indicates whether the breakpoint is pending.
554 ** Three new breakpoint-related events have been added:
555 gdb.breakpoint_created, gdb.breakpoint_modified, and
556 gdb.breakpoint_deleted.
559 Signal ("set") the given MS-Windows event object. This is used in
560 conjunction with the Windows JIT debugging (AeDebug) support, where
561 the OS suspends a crashing process until a debugger can attach to
562 it. Resuming the crashing process, in order to debug it, is done by
565 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
566 was added in GDBserver, including JIT compiling fast tracepoint's
567 conditional expression bytecode into native code.
569 * Support for various remote target protocols and ROM monitors has
572 target m32rsdi Remote M32R debugging over SDI
573 target mips MIPS remote debugging protocol
574 target pmon PMON ROM monitor
575 target ddb NEC's DDB variant of PMON for Vr4300
576 target rockhopper NEC RockHopper variant of PMON
577 target lsi LSI variant of PMO
579 * Support for tracepoints and fast tracepoints on powerpc-linux,
580 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
581 including JIT compiling fast tracepoint's conditional expression
582 bytecode into native code.
584 * MI async record =record-started now includes the method and format used for
585 recording. For example:
587 =record-started,thread-group="i1",method="btrace",format="bts"
589 * MI async record =thread-selected now includes the frame field. For example:
591 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
595 Andes NDS32 nds32*-*-elf
597 *** Changes in GDB 7.11
599 * GDB now supports debugging kernel-based threads on FreeBSD.
601 * Per-inferior thread numbers
603 Thread numbers are now per inferior instead of global. If you're
604 debugging multiple inferiors, GDB displays thread IDs using a
605 qualified INF_NUM.THR_NUM form. For example:
609 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
610 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
611 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
612 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
614 As consequence, thread numbers as visible in the $_thread
615 convenience variable and in Python's InferiorThread.num attribute
616 are no longer unique between inferiors.
618 GDB now maintains a second thread ID per thread, referred to as the
619 global thread ID, which is the new equivalent of thread numbers in
620 previous releases. See also $_gthread below.
622 For backwards compatibility, MI's thread IDs always refer to global
625 * Commands that accept thread IDs now accept the qualified
626 INF_NUM.THR_NUM form as well. For example:
629 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
632 * In commands that accept a list of thread IDs, you can now refer to
633 all threads of an inferior using a star wildcard. GDB accepts
634 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
635 refer to all threads of the current inferior. For example, "info
638 * You can use "info threads -gid" to display the global thread ID of
641 * The new convenience variable $_gthread holds the global number of
644 * The new convenience variable $_inferior holds the number of the
647 * GDB now displays the ID and name of the thread that hit a breakpoint
648 or received a signal, if your program is multi-threaded. For
651 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
652 Thread 1 "main" received signal SIGINT, Interrupt.
654 * Record btrace now supports non-stop mode.
656 * Support for tracepoints on aarch64-linux was added in GDBserver.
658 * The 'record instruction-history' command now indicates speculative execution
659 when using the Intel Processor Trace recording format.
661 * GDB now allows users to specify explicit locations, bypassing
662 the linespec parser. This feature is also available to GDB/MI
665 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
666 GDB now is able to debug both AArch64 applications and ARM applications
669 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
670 including JIT compiling fast tracepoint's conditional expression bytecode
673 * GDB now supports displaced stepping on AArch64 GNU/Linux.
675 * "info threads", "info inferiors", "info display", "info checkpoints"
676 and "maint info program-spaces" now list the corresponding items in
677 ascending ID order, for consistency with all other "info" commands.
679 * In Ada, the overloads selection menu has been enhanced to display the
680 parameter types and the return types for the matching overloaded subprograms.
684 maint set target-non-stop (on|off|auto)
685 maint show target-non-stop
686 Control whether GDB targets always operate in non-stop mode even if
687 "set non-stop" is "off". The default is "auto", meaning non-stop
688 mode is enabled if supported by the target.
690 maint set bfd-sharing
691 maint show bfd-sharing
692 Control the reuse of bfd objects.
696 Control display of debugging info regarding bfd caching.
700 Control display of debugging info regarding FreeBSD threads.
702 set remote multiprocess-extensions-packet
703 show remote multiprocess-extensions-packet
704 Set/show the use of the remote protocol multiprocess extensions.
706 set remote thread-events
707 show remote thread-events
708 Set/show the use of thread create/exit events.
710 set ada print-signatures on|off
711 show ada print-signatures"
712 Control whether parameter types and return types are displayed in overloads
713 selection menus. It is activaled (@code{on}) by default.
717 Controls the maximum size of memory, in bytes, that GDB will
718 allocate for value contents. Prevents incorrect programs from
719 causing GDB to allocate overly large buffers. Default is 64k.
721 * The "disassemble" command accepts a new modifier: /s.
722 It prints mixed source+disassembly like /m with two differences:
723 - disassembled instructions are now printed in program order, and
724 - and source for all relevant files is now printed.
725 The "/m" option is now considered deprecated: its "source-centric"
726 output hasn't proved useful in practice.
728 * The "record instruction-history" command accepts a new modifier: /s.
729 It behaves exactly like /m and prints mixed source+disassembly.
731 * The "set scheduler-locking" command supports a new mode "replay".
732 It behaves like "off" in record mode and like "on" in replay mode.
734 * Support for various ROM monitors has been removed:
736 target dbug dBUG ROM monitor for Motorola ColdFire
737 target picobug Motorola picobug monitor
738 target dink32 DINK32 ROM monitor for PowerPC
739 target m32r Renesas M32R/D ROM monitor
740 target mon2000 mon2000 ROM monitor
741 target ppcbug PPCBUG ROM monitor for PowerPC
743 * Support for reading/writing memory and extracting values on architectures
744 whose memory is addressable in units of any integral multiple of 8 bits.
747 Allows to break when an Ada exception is handled.
752 Indicates that an exec system call was executed.
754 exec-events feature in qSupported
755 The qSupported packet allows GDB to request support for exec
756 events using the new 'gdbfeature' exec-event, and the qSupported
757 response can contain the corresponding 'stubfeature'. Set and
758 show commands can be used to display whether these features are enabled.
761 Equivalent to interrupting with the ^C character, but works in
764 thread created stop reason (T05 create:...)
765 Indicates that the thread was just created and is stopped at entry.
767 thread exit stop reply (w exitcode;tid)
768 Indicates that the thread has terminated.
771 Enables/disables thread create and exit event reporting. For
772 example, this is used in non-stop mode when GDB stops a set of
773 threads and synchronously waits for the their corresponding stop
774 replies. Without exit events, if one of the threads exits, GDB
775 would hang forever not knowing that it should no longer expect a
776 stop for that same thread.
779 Indicates that there are no resumed threads left in the target (all
780 threads are stopped). The remote stub reports support for this stop
781 reply to GDB's qSupported query.
784 Enables/disables catching syscalls from the inferior process.
785 The remote stub reports support for this packet to GDB's qSupported query.
787 syscall_entry stop reason
788 Indicates that a syscall was just called.
790 syscall_return stop reason
791 Indicates that a syscall just returned.
793 * Extended-remote exec events
795 ** GDB now has support for exec events on extended-remote Linux targets.
796 For such targets with Linux kernels 2.5.46 and later, this enables
797 follow-exec-mode and exec catchpoints.
799 set remote exec-event-feature-packet
800 show remote exec-event-feature-packet
801 Set/show the use of the remote exec event feature.
803 * Thread names in remote protocol
805 The reply to qXfer:threads:read may now include a name attribute for each
808 * Target remote mode fork and exec events
810 ** GDB now has support for fork and exec events on target remote mode
811 Linux targets. For such targets with Linux kernels 2.5.46 and later,
812 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
813 fork and exec catchpoints.
815 * Remote syscall events
817 ** GDB now has support for catch syscall on remote Linux targets,
818 currently enabled on x86/x86_64 architectures.
820 set remote catch-syscall-packet
821 show remote catch-syscall-packet
822 Set/show the use of the remote catch syscall feature.
826 ** The -var-set-format command now accepts the zero-hexadecimal
827 format. It outputs data in hexadecimal format with zero-padding on the
832 ** gdb.InferiorThread objects have a new attribute "global_num",
833 which refers to the thread's global thread ID. The existing
834 "num" attribute now refers to the thread's per-inferior number.
835 See "Per-inferior thread numbers" above.
836 ** gdb.InferiorThread objects have a new attribute "inferior", which
837 is the Inferior object the thread belongs to.
839 *** Changes in GDB 7.10
841 * Support for process record-replay and reverse debugging on aarch64*-linux*
842 targets has been added. GDB now supports recording of A64 instruction set
843 including advance SIMD instructions.
845 * Support for Sun's version of the "stabs" debug file format has been removed.
847 * GDB now honors the content of the file /proc/PID/coredump_filter
848 (PID is the process ID) on GNU/Linux systems. This file can be used
849 to specify the types of memory mappings that will be included in a
850 corefile. For more information, please refer to the manual page of
851 "core(5)". GDB also has a new command: "set use-coredump-filter
852 on|off". It allows to set whether GDB will read the content of the
853 /proc/PID/coredump_filter file when generating a corefile.
855 * The "info os" command on GNU/Linux can now display information on
857 "info os cpus" Listing of all cpus/cores on the system
859 * GDB has two new commands: "set serial parity odd|even|none" and
860 "show serial parity". These allows to set or show parity for the
863 * The "info source" command now displays the producer string if it was
864 present in the debug info. This typically includes the compiler version
865 and may include things like its command line arguments.
867 * The "info dll", an alias of the "info sharedlibrary" command,
868 is now available on all platforms.
870 * Directory names supplied to the "set sysroot" commands may be
871 prefixed with "target:" to tell GDB to access shared libraries from
872 the target system, be it local or remote. This replaces the prefix
873 "remote:". The default sysroot has been changed from "" to
874 "target:". "remote:" is automatically converted to "target:" for
875 backward compatibility.
877 * The system root specified by "set sysroot" will be prepended to the
878 filename of the main executable (if reported to GDB as absolute by
879 the operating system) when starting processes remotely, and when
880 attaching to already-running local or remote processes.
882 * GDB now supports automatic location and retrieval of executable
883 files from remote targets. Remote debugging can now be initiated
884 using only a "target remote" or "target extended-remote" command
885 (no "set sysroot" or "file" commands are required). See "New remote
888 * The "dump" command now supports verilog hex format.
890 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
892 * On GNU/Linux, GDB and gdbserver are now able to access executable
893 and shared library files without a "set sysroot" command when
894 attaching to processes running in different mount namespaces from
895 the debugger. This makes it possible to attach to processes in
896 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
897 See "New remote packets" below.
899 * The "tui reg" command now provides completion for all of the
900 available register groups, including target specific groups.
902 * The HISTSIZE environment variable is no longer read when determining
903 the size of GDB's command history. GDB now instead reads the dedicated
904 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
905 disables truncation of command history. Non-numeric values of GDBHISTSIZE
910 ** Memory ports can now be unbuffered.
914 ** gdb.Objfile objects have a new attribute "username",
915 which is the name of the objfile as specified by the user,
916 without, for example, resolving symlinks.
917 ** You can now write frame unwinders in Python.
918 ** gdb.Type objects have a new method "optimized_out",
919 returning optimized out gdb.Value instance of this type.
920 ** gdb.Value objects have new methods "reference_value" and
921 "const_value" which return a reference to the value and a
922 "const" version of the value respectively.
926 maint print symbol-cache
927 Print the contents of the symbol cache.
929 maint print symbol-cache-statistics
930 Print statistics of symbol cache usage.
932 maint flush-symbol-cache
933 Flush the contents of the symbol cache.
937 Start branch trace recording using Branch Trace Store (BTS) format.
940 Evaluate expression by using the compiler and print result.
944 Explicit commands for enabling and disabling tui mode.
947 set mpx bound on i386 and amd64
948 Support for bound table investigation on Intel MPX enabled applications.
952 Start branch trace recording using Intel Processor Trace format.
955 Print information about branch tracing internals.
957 maint btrace packet-history
958 Print the raw branch tracing data.
960 maint btrace clear-packet-history
961 Discard the stored raw branch tracing data.
964 Discard all branch tracing data. It will be fetched and processed
965 anew by the next "record" command.
970 Renamed from "set debug dwarf2-die".
972 Renamed from "show debug dwarf2-die".
975 Renamed from "set debug dwarf2-read".
976 show debug dwarf-read
977 Renamed from "show debug dwarf2-read".
979 maint set dwarf always-disassemble
980 Renamed from "maint set dwarf2 always-disassemble".
981 maint show dwarf always-disassemble
982 Renamed from "maint show dwarf2 always-disassemble".
984 maint set dwarf max-cache-age
985 Renamed from "maint set dwarf2 max-cache-age".
986 maint show dwarf max-cache-age
987 Renamed from "maint show dwarf2 max-cache-age".
990 show debug dwarf-line
991 Control display of debugging info regarding DWARF line processing.
995 Set the maximum number of candidates to be considered during
996 completion. The default value is 200. This limit allows GDB
997 to avoid generating large completion lists, the computation of
998 which can cause the debugger to become temporarily unresponsive.
1000 set history remove-duplicates
1001 show history remove-duplicates
1002 Control the removal of duplicate history entries.
1004 maint set symbol-cache-size
1005 maint show symbol-cache-size
1006 Control the size of the symbol cache.
1008 set|show record btrace bts buffer-size
1009 Set and show the size of the ring buffer used for branch tracing in
1011 The obtained size may differ from the requested size. Use "info
1012 record" to see the obtained buffer size.
1014 set debug linux-namespaces
1015 show debug linux-namespaces
1016 Control display of debugging info regarding Linux namespaces.
1018 set|show record btrace pt buffer-size
1019 Set and show the size of the ring buffer used for branch tracing in
1020 Intel Processor Trace format.
1021 The obtained size may differ from the requested size. Use "info
1022 record" to see the obtained buffer size.
1024 maint set|show btrace pt skip-pad
1025 Set and show whether PAD packets are skipped when computing the
1028 * The command 'thread apply all' can now support new option '-ascending'
1029 to call its specified command for all threads in ascending order.
1031 * Python/Guile scripting
1033 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1034 special section named `.debug_gdb_scripts'.
1036 * New remote packets
1038 qXfer:btrace-conf:read
1039 Return the branch trace configuration for the current thread.
1041 Qbtrace-conf:bts:size
1042 Set the requested ring buffer size for branch tracing in BTS format.
1045 Enable Intel Procesor Trace-based branch tracing for the current
1046 process. The remote stub reports support for this packet to GDB's
1049 Qbtrace-conf:pt:size
1050 Set the requested ring buffer size for branch tracing in Intel Processor
1054 Indicates a memory breakpoint instruction was executed, irrespective
1055 of whether it was GDB that planted the breakpoint or the breakpoint
1056 is hardcoded in the program. This is required for correct non-stop
1060 Indicates the target stopped for a hardware breakpoint. This is
1061 required for correct non-stop mode operation.
1064 Return information about files on the remote system.
1066 qXfer:exec-file:read
1067 Return the full absolute name of the file that was executed to
1068 create a process running on the remote system.
1071 Select the filesystem on which vFile: operations with filename
1072 arguments will operate. This is required for GDB to be able to
1073 access files on remote targets where the remote stub does not
1074 share a common filesystem with the inferior(s).
1077 Indicates that a fork system call was executed.
1080 Indicates that a vfork system call was executed.
1082 vforkdone stop reason
1083 Indicates that a vfork child of the specified process has executed
1084 an exec or exit, allowing the vfork parent to resume execution.
1086 fork-events and vfork-events features in qSupported
1087 The qSupported packet allows GDB to request support for fork and
1088 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1089 and the qSupported response can contain the corresponding
1090 'stubfeatures'. Set and show commands can be used to display
1091 whether these features are enabled.
1093 * Extended-remote fork events
1095 ** GDB now has support for fork events on extended-remote Linux
1096 targets. For targets with Linux kernels 2.5.60 and later, this
1097 enables follow-fork-mode and detach-on-fork for both fork and
1098 vfork, as well as fork and vfork catchpoints.
1100 * The info record command now shows the recording format and the
1101 branch tracing configuration for the current thread when using
1102 the btrace record target.
1103 For the BTS format, it shows the ring buffer size.
1105 * GDB now has support for DTrace USDT (Userland Static Defined
1106 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1108 * GDB now supports access to vector registers on S/390 GNU/Linux
1111 * Removed command line options
1113 -xdb HP-UX XDB compatibility mode.
1115 * Removed targets and native configurations
1117 HP/PA running HP-UX hppa*-*-hpux*
1118 Itanium running HP-UX ia64-*-hpux*
1120 * New configure options
1123 This configure option allows the user to build GDB with support for
1124 Intel Processor Trace (default: auto). This requires libipt.
1126 --with-libipt-prefix=PATH
1127 Specify the path to the version of libipt that GDB should use.
1128 $PATH/include should contain the intel-pt.h header and
1129 $PATH/lib should contain the libipt.so library.
1131 *** Changes in GDB 7.9.1
1135 ** Xmethods can now specify a result type.
1137 *** Changes in GDB 7.9
1139 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1143 ** You can now access frame registers from Python scripts.
1144 ** New attribute 'producer' for gdb.Symtab objects.
1145 ** gdb.Objfile objects have a new attribute "progspace",
1146 which is the gdb.Progspace object of the containing program space.
1147 ** gdb.Objfile objects have a new attribute "owner".
1148 ** gdb.Objfile objects have a new attribute "build_id",
1149 which is the build ID generated when the file was built.
1150 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1151 ** A new event "gdb.clear_objfiles" has been added, triggered when
1152 selecting a new file to debug.
1153 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1154 ** New function gdb.lookup_objfile.
1156 New events which are triggered when GDB modifies the state of the
1159 ** gdb.events.inferior_call_pre: Function call is about to be made.
1160 ** gdb.events.inferior_call_post: Function call has just been made.
1161 ** gdb.events.memory_changed: A memory location has been altered.
1162 ** gdb.events.register_changed: A register has been altered.
1164 * New Python-based convenience functions:
1166 ** $_caller_is(name [, number_of_frames])
1167 ** $_caller_matches(regexp [, number_of_frames])
1168 ** $_any_caller_is(name [, number_of_frames])
1169 ** $_any_caller_matches(regexp [, number_of_frames])
1171 * GDB now supports the compilation and injection of source code into
1172 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1173 to compile the source code to object code, and if successful, inject
1174 and execute that code within the current context of the inferior.
1175 Currently the C language is supported. The commands used to
1176 interface with this new feature are:
1178 compile code [-raw|-r] [--] [source code]
1179 compile file [-raw|-r] filename
1183 demangle [-l language] [--] name
1184 Demangle "name" in the specified language, or the current language
1185 if elided. This command is renamed from the "maint demangle" command.
1186 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1187 as "maint demangler-warning".
1189 queue-signal signal-name-or-number
1190 Queue a signal to be delivered to the thread when it is resumed.
1192 add-auto-load-scripts-directory directory
1193 Add entries to the list of directories from which to load auto-loaded
1196 maint print user-registers
1197 List all currently available "user" registers.
1199 compile code [-r|-raw] [--] [source code]
1200 Compile, inject, and execute in the inferior the executable object
1201 code produced by compiling the provided source code.
1203 compile file [-r|-raw] filename
1204 Compile and inject into the inferior the executable object code
1205 produced by compiling the source code stored in the filename
1208 * On resume, GDB now always passes the signal the program had stopped
1209 for to the thread the signal was sent to, even if the user changed
1210 threads before resuming. Previously GDB would often (but not
1211 always) deliver the signal to the thread that happens to be current
1214 * Conversely, the "signal" command now consistently delivers the
1215 requested signal to the current thread. GDB now asks for
1216 confirmation if the program had stopped for a signal and the user
1217 switched threads meanwhile.
1219 * "breakpoint always-inserted" modes "off" and "auto" merged.
1221 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1222 won't remove breakpoints from the target until all threads stop,
1223 even in non-stop mode. The "auto" mode has been removed, and "off"
1224 is now the default mode.
1228 set debug symbol-lookup
1229 show debug symbol-lookup
1230 Control display of debugging info regarding symbol lookup.
1234 ** The -list-thread-groups command outputs an exit-code field for
1235 inferiors that have exited.
1239 MIPS SDE mips*-sde*-elf*
1243 Support for these obsolete configurations has been removed.
1245 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1246 SGI Irix-5.x mips-*-irix5*
1247 SGI Irix-6.x mips-*-irix6*
1248 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1249 VAX running Ultrix vax-*-ultrix*
1251 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1252 and "assf"), have been removed. Use the "sharedlibrary" command, or
1253 its alias "share", instead.
1255 *** Changes in GDB 7.8
1257 * New command line options
1260 This is an alias for the --data-directory option.
1262 * GDB supports printing and modifying of variable length automatic arrays
1263 as specified in ISO C99.
1265 * The ARM simulator now supports instruction level tracing
1266 with or without disassembly.
1270 GDB now has support for scripting using Guile. Whether this is
1271 available is determined at configure time.
1272 Guile version 2.0 or greater is required.
1273 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1275 * New commands (for set/show, see "New options" below)
1279 Invoke CODE by passing it to the Guile interpreter.
1283 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1285 info auto-load guile-scripts [regexp]
1286 Print the list of automatically loaded Guile scripts.
1288 * The source command is now capable of sourcing Guile scripts.
1289 This feature is dependent on the debugger being built with Guile support.
1293 set print symbol-loading (off|brief|full)
1294 show print symbol-loading
1295 Control whether to print informational messages when loading symbol
1296 information for a file. The default is "full", but when debugging
1297 programs with large numbers of shared libraries the amount of output
1298 becomes less useful.
1300 set guile print-stack (none|message|full)
1301 show guile print-stack
1302 Show a stack trace when an error is encountered in a Guile script.
1304 set auto-load guile-scripts (on|off)
1305 show auto-load guile-scripts
1306 Control auto-loading of Guile script files.
1308 maint ada set ignore-descriptive-types (on|off)
1309 maint ada show ignore-descriptive-types
1310 Control whether the debugger should ignore descriptive types in Ada
1311 programs. The default is not to ignore the descriptive types. See
1312 the user manual for more details on descriptive types and the intended
1313 usage of this option.
1315 set auto-connect-native-target
1317 Control whether GDB is allowed to automatically connect to the
1318 native target for the run, attach, etc. commands when not connected
1319 to any target yet. See also "target native" below.
1321 set record btrace replay-memory-access (read-only|read-write)
1322 show record btrace replay-memory-access
1323 Control what memory accesses are allowed during replay.
1325 maint set target-async (on|off)
1326 maint show target-async
1327 This controls whether GDB targets operate in synchronous or
1328 asynchronous mode. Normally the default is asynchronous, if it is
1329 available; but this can be changed to more easily debug problems
1330 occurring only in synchronous mode.
1332 set mi-async (on|off)
1334 Control whether MI asynchronous mode is preferred. This supersedes
1335 "set target-async" of previous GDB versions.
1337 * "set target-async" is deprecated as a CLI option and is now an alias
1338 for "set mi-async" (only puts MI into async mode).
1340 * Background execution commands (e.g., "c&", "s&", etc.) are now
1341 possible ``out of the box'' if the target supports them. Previously
1342 the user would need to explicitly enable the possibility with the
1343 "set target-async on" command.
1345 * New features in the GDB remote stub, GDBserver
1347 ** New option --debug-format=option1[,option2,...] allows one to add
1348 additional text to each output. At present only timestamps
1349 are supported: --debug-format=timestamps.
1350 Timestamps can also be turned on with the
1351 "monitor set debug-format timestamps" command from GDB.
1353 * The 'record instruction-history' command now starts counting instructions
1354 at one. This also affects the instruction ranges reported by the
1355 'record function-call-history' command when given the /i modifier.
1357 * The command 'record function-call-history' supports a new modifier '/c' to
1358 indent the function names based on their call stack depth.
1359 The fields for the '/i' and '/l' modifier have been reordered.
1360 The source line range is now prefixed with 'at'.
1361 The instruction range is now prefixed with 'inst'.
1362 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1363 "record instruction-history" and "list" commands.
1365 * The ranges given as arguments to the 'record function-call-history' and
1366 'record instruction-history' commands are now inclusive.
1368 * The btrace record target now supports the 'record goto' command.
1369 For locations inside the execution trace, the back trace is computed
1370 based on the information stored in the execution trace.
1372 * The btrace record target supports limited reverse execution and replay.
1373 The target does not record data and therefore does not allow reading
1374 memory or registers.
1376 * The "catch syscall" command now works on s390*-linux* targets.
1378 * The "compare-sections" command is no longer specific to target
1379 remote. It now works with all targets.
1381 * All native targets are now consistently called "native".
1382 Consequently, the "target child", "target GNU", "target djgpp",
1383 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1384 commands have been replaced with "target native". The QNX/NTO port
1385 leaves the "procfs" target in place and adds a "native" target for
1386 consistency with other ports. The impact on users should be minimal
1387 as these commands previously either throwed an error, or were
1388 no-ops. The target's name is visible in the output of the following
1389 commands: "help target", "info target", "info files", "maint print
1392 * The "target native" command now connects to the native target. This
1393 can be used to launch native programs even when "set
1394 auto-connect-native-target" is set to off.
1396 * GDB now supports access to Intel MPX registers on GNU/Linux.
1398 * Support for Intel AVX-512 registers on GNU/Linux.
1399 Support displaying and modifying Intel AVX-512 registers
1400 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1402 * New remote packets
1404 qXfer:btrace:read's annex
1405 The qXfer:btrace:read packet supports a new annex 'delta' to read
1406 branch trace incrementally.
1410 ** Valid Python operations on gdb.Value objects representing
1411 structs/classes invoke the corresponding overloaded operators if
1413 ** New `Xmethods' feature in the Python API. Xmethods are
1414 additional methods or replacements for existing methods of a C++
1415 class. This feature is useful for those cases where a method
1416 defined in C++ source code could be inlined or optimized out by
1417 the compiler, making it unavailable to GDB.
1420 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1422 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1423 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1424 its alias "share", instead.
1426 * The commands "set remotebaud" and "show remotebaud" are no longer
1427 supported. Use "set serial baud" and "show serial baud" (respectively)
1432 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1433 target-async". The latter is left as a deprecated alias of the
1434 former for backward compatibility. If the target supports it,
1435 CLI background execution commands are now always possible by
1436 default, independently of whether the frontend stated a
1437 preference for asynchronous execution with "-gdb-set mi-async".
1438 Previously "-gdb-set target-async off" affected both MI execution
1439 commands and CLI execution commands.
1441 *** Changes in GDB 7.7
1443 * Improved support for process record-replay and reverse debugging on
1444 arm*-linux* targets. Support for thumb32 and syscall instruction
1445 recording has been added.
1447 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1449 * GDB now supports Fission DWP file format version 2.
1450 http://gcc.gnu.org/wiki/DebugFission
1452 * New convenience function "$_isvoid", to check whether an expression
1453 is void. A void expression is an expression where the type of the
1454 result is "void". For example, some convenience variables may be
1455 "void" when evaluated (e.g., "$_exitcode" before the execution of
1456 the program being debugged; or an undefined convenience variable).
1457 Another example, when calling a function whose return type is
1460 * The "maintenance print objfiles" command now takes an optional regexp.
1462 * The "catch syscall" command now works on arm*-linux* targets.
1464 * GDB now consistently shows "<not saved>" when printing values of
1465 registers the debug info indicates have not been saved in the frame
1466 and there's nowhere to retrieve them from
1467 (callee-saved/call-clobbered registers):
1472 (gdb) info registers rax
1475 Before, the former would print "<optimized out>", and the latter
1476 "*value not available*".
1478 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1483 ** Frame filters and frame decorators have been added.
1484 ** Temporary breakpoints are now supported.
1485 ** Line tables representation has been added.
1486 ** New attribute 'parent_type' for gdb.Field objects.
1487 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1488 ** New attribute 'name' for gdb.Type objects.
1492 Nios II ELF nios2*-*-elf
1493 Nios II GNU/Linux nios2*-*-linux
1494 Texas Instruments MSP430 msp430*-*-elf
1496 * Removed native configurations
1498 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1499 been removed. ELF variants of these configurations are kept supported.
1501 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1502 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1503 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1504 i[34567]86-*-openbsd3.[0-3]
1505 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1506 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1507 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1511 Like "catch throw", but catches a re-thrown exception.
1512 maint check-psymtabs
1513 Renamed from old "maint check-symtabs".
1515 Perform consistency checks on symtabs.
1516 maint expand-symtabs
1517 Expand symtabs matching an optional regexp.
1520 Display the details of GDB configure-time options.
1522 maint set|show per-command
1523 maint set|show per-command space
1524 maint set|show per-command time
1525 maint set|show per-command symtab
1526 Enable display of per-command gdb resource usage.
1528 remove-symbol-file FILENAME
1529 remove-symbol-file -a ADDRESS
1530 Remove a symbol file added via add-symbol-file. The file to remove
1531 can be identified by its filename or by an address that lies within
1532 the boundaries of this symbol file in memory.
1535 info exceptions REGEXP
1536 Display the list of Ada exceptions defined in the program being
1537 debugged. If provided, only the exceptions whose names match REGEXP
1542 set debug symfile off|on
1544 Control display of debugging info regarding reading symbol files and
1545 symbol tables within those files
1547 set print raw frame-arguments
1548 show print raw frame-arguments
1549 Set/show whether to print frame arguments in raw mode,
1550 disregarding any defined pretty-printers.
1552 set remote trace-status-packet
1553 show remote trace-status-packet
1554 Set/show the use of remote protocol qTStatus packet.
1558 Control display of debugging messages related to Nios II targets.
1562 Control whether target-assisted range stepping is enabled.
1564 set startup-with-shell
1565 show startup-with-shell
1566 Specifies whether Unix child processes are started via a shell or
1571 Use the target memory cache for accesses to the code segment. This
1572 improves performance of remote debugging (particularly disassembly).
1574 * You can now use a literal value 'unlimited' for options that
1575 interpret 0 or -1 as meaning "unlimited". E.g., "set
1576 trace-buffer-size unlimited" is now an alias for "set
1577 trace-buffer-size -1" and "set height unlimited" is now an alias for
1580 * The "set debug symtab-create" debugging option of GDB has been changed to
1581 accept a verbosity level. 0 means "off", 1 provides basic debugging
1582 output, and values of 2 or greater provides more verbose output.
1584 * New command-line options
1586 Display the details of GDB configure-time options.
1588 * The command 'tsave' can now support new option '-ctf' to save trace
1589 buffer in Common Trace Format.
1591 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1594 * GDB now implements the the C++ 'typeid' operator.
1596 * The new convenience variable $_exception holds the exception being
1597 thrown or caught at an exception-related catchpoint.
1599 * The exception-related catchpoints, like "catch throw", now accept a
1600 regular expression which can be used to filter exceptions by type.
1602 * The new convenience variable $_exitsignal is automatically set to
1603 the terminating signal number when the program being debugged dies
1604 due to an uncaught signal.
1608 ** All MI commands now accept an optional "--language" option.
1609 Support for this feature can be verified by using the "-list-features"
1610 command, which should contain "language-option".
1612 ** The new command -info-gdb-mi-command allows the user to determine
1613 whether a GDB/MI command is supported or not.
1615 ** The "^error" result record returned when trying to execute an undefined
1616 GDB/MI command now provides a variable named "code" whose content is the
1617 "undefined-command" error code. Support for this feature can be verified
1618 by using the "-list-features" command, which should contain
1619 "undefined-command-error-code".
1621 ** The -trace-save MI command can optionally save trace buffer in Common
1624 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1626 ** The command -data-list-register-values now accepts an optional
1627 "--skip-unavailable" option. When used, only the available registers
1630 ** The new command -trace-frame-collected dumps collected variables,
1631 computed expressions, tvars, memory and registers in a traceframe.
1633 ** The commands -stack-list-locals, -stack-list-arguments and
1634 -stack-list-variables now accept an option "--skip-unavailable".
1635 When used, only the available locals or arguments are displayed.
1637 ** The -exec-run command now accepts an optional "--start" option.
1638 When used, the command follows the same semantics as the "start"
1639 command, stopping the program's execution at the start of its
1640 main subprogram. Support for this feature can be verified using
1641 the "-list-features" command, which should contain
1642 "exec-run-start-option".
1644 ** The new commands -catch-assert and -catch-exceptions insert
1645 catchpoints stopping the program when Ada exceptions are raised.
1647 ** The new command -info-ada-exceptions provides the equivalent of
1648 the new "info exceptions" command.
1650 * New system-wide configuration scripts
1651 A GDB installation now provides scripts suitable for use as system-wide
1652 configuration scripts for the following systems:
1656 * GDB now supports target-assigned range stepping with remote targets.
1657 This improves the performance of stepping source lines by reducing
1658 the number of control packets from/to GDB. See "New remote packets"
1661 * GDB now understands the element 'tvar' in the XML traceframe info.
1662 It has the id of the collected trace state variables.
1664 * On S/390 targets that provide the transactional-execution feature,
1665 the program interruption transaction diagnostic block (TDB) is now
1666 represented as a number of additional "registers" in GDB.
1668 * New remote packets
1672 The vCont packet supports a new 'r' action, that tells the remote
1673 stub to step through an address range itself, without GDB
1674 involvemement at each single-step.
1676 qXfer:libraries-svr4:read's annex
1677 The previously unused annex of the qXfer:libraries-svr4:read packet
1678 is now used to support passing an argument list. The remote stub
1679 reports support for this argument list to GDB's qSupported query.
1680 The defined arguments are "start" and "prev", used to reduce work
1681 necessary for library list updating, resulting in significant
1684 * New features in the GDB remote stub, GDBserver
1686 ** GDBserver now supports target-assisted range stepping. Currently
1687 enabled on x86/x86_64 GNU/Linux targets.
1689 ** GDBserver now adds element 'tvar' in the XML in the reply to
1690 'qXfer:traceframe-info:read'. It has the id of the collected
1691 trace state variables.
1693 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1696 * New 'z' formatter for printing and examining memory, this displays the
1697 value as hexadecimal zero padded on the left to the size of the type.
1699 * GDB can now use Windows x64 unwinding data.
1701 * The "set remotebaud" command has been replaced by "set serial baud".
1702 Similarly, "show remotebaud" has been replaced by "show serial baud".
1703 The "set remotebaud" and "show remotebaud" commands are still available
1704 to provide backward compatibility with older versions of GDB.
1706 *** Changes in GDB 7.6
1708 * Target record has been renamed to record-full.
1709 Record/replay is now enabled with the "record full" command.
1710 This also affects settings that are associated with full record/replay
1711 that have been moved from "set/show record" to "set/show record full":
1713 set|show record full insn-number-max
1714 set|show record full stop-at-limit
1715 set|show record full memory-query
1717 * A new record target "record-btrace" has been added. The new target
1718 uses hardware support to record the control-flow of a process. It
1719 does not support replaying the execution, but it implements the
1720 below new commands for investigating the recorded execution log.
1721 This new recording method can be enabled using:
1725 The "record-btrace" target is only available on Intel Atom processors
1726 and requires a Linux kernel 2.6.32 or later.
1728 * Two new commands have been added for record/replay to give information
1729 about the recorded execution without having to replay the execution.
1730 The commands are only supported by "record btrace".
1732 record instruction-history prints the execution history at
1733 instruction granularity
1735 record function-call-history prints the execution history at
1736 function granularity
1738 * New native configurations
1740 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1741 FreeBSD/powerpc powerpc*-*-freebsd
1742 x86_64/Cygwin x86_64-*-cygwin*
1743 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1747 ARM AArch64 aarch64*-*-elf
1748 ARM AArch64 GNU/Linux aarch64*-*-linux
1749 Lynx 178 PowerPC powerpc-*-lynx*178
1750 x86_64/Cygwin x86_64-*-cygwin*
1751 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1753 * If the configured location of system.gdbinit file (as given by the
1754 --with-system-gdbinit option at configure time) is in the
1755 data-directory (as specified by --with-gdb-datadir at configure
1756 time) or in one of its subdirectories, then GDB will look for the
1757 system-wide init file in the directory specified by the
1758 --data-directory command-line option.
1760 * New command line options:
1762 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1763 other initialization files, unlike -nx which disables all of them.
1765 * Removed command line options
1767 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1770 * The 'ptype' and 'whatis' commands now accept an argument to control
1773 * 'info proc' now works on some core files.
1777 ** Vectors can be created with gdb.Type.vector.
1779 ** Python's atexit.register now works in GDB.
1781 ** Types can be pretty-printed via a Python API.
1783 ** Python 3 is now supported (in addition to Python 2.4 or later)
1785 ** New class gdb.Architecture exposes GDB's internal representation
1786 of architecture in the Python API.
1788 ** New method Frame.architecture returns the gdb.Architecture object
1789 corresponding to the frame's architecture.
1791 * New Python-based convenience functions:
1793 ** $_memeq(buf1, buf2, length)
1794 ** $_streq(str1, str2)
1796 ** $_regex(str, regex)
1798 * The 'cd' command now defaults to using '~' (the home directory) if not
1801 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1802 default for GCC since November 2000.
1804 * The command 'forward-search' can now be abbreviated as 'fo'.
1806 * The command 'info tracepoints' can now display 'installed on target'
1807 or 'not installed on target' for each non-pending location of tracepoint.
1809 * New configure options
1811 --enable-libmcheck/--disable-libmcheck
1812 By default, development versions are built with -lmcheck on hosts
1813 that support it, in order to help track memory corruption issues.
1814 Release versions, on the other hand, are built without -lmcheck
1815 by default. The --enable-libmcheck/--disable-libmcheck configure
1816 options allow the user to override that default.
1817 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1818 This configure option allows the user to build GDB with
1819 libbabeltrace using which GDB can read Common Trace Format data.
1821 * New commands (for set/show, see "New options" below)
1824 Catch signals. This is similar to "handle", but allows commands and
1825 conditions to be attached.
1828 List the BFDs known to GDB.
1830 python-interactive [command]
1832 Start a Python interactive prompt, or evaluate the optional command
1833 and print the result of expressions.
1836 "py" is a new alias for "python".
1838 enable type-printer [name]...
1839 disable type-printer [name]...
1840 Enable or disable type printers.
1844 ** For the Renesas Super-H architecture, the "regs" command has been removed
1845 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1850 set print type methods (on|off)
1851 show print type methods
1852 Control whether method declarations are displayed by "ptype".
1853 The default is to show them.
1855 set print type typedefs (on|off)
1856 show print type typedefs
1857 Control whether typedef definitions are displayed by "ptype".
1858 The default is to show them.
1860 set filename-display basename|relative|absolute
1861 show filename-display
1862 Control the way in which filenames is displayed.
1863 The default is "relative", which preserves previous behavior.
1865 set trace-buffer-size
1866 show trace-buffer-size
1867 Request target to change the size of trace buffer.
1869 set remote trace-buffer-size-packet auto|on|off
1870 show remote trace-buffer-size-packet
1871 Control the use of the remote protocol `QTBuffer:size' packet.
1875 Control display of debugging messages related to ARM AArch64.
1878 set debug coff-pe-read
1879 show debug coff-pe-read
1880 Control display of debugging messages related to reading of COFF/PE
1885 Control display of debugging messages related to Mach-O symbols
1888 set debug notification
1889 show debug notification
1890 Control display of debugging info for async remote notification.
1894 ** Command parameter changes are now notified using new async record
1895 "=cmd-param-changed".
1896 ** Trace frame changes caused by command "tfind" are now notified using
1897 new async record "=traceframe-changed".
1898 ** The creation, deletion and modification of trace state variables
1899 are now notified using new async records "=tsv-created",
1900 "=tsv-deleted" and "=tsv-modified".
1901 ** The start and stop of process record are now notified using new
1902 async record "=record-started" and "=record-stopped".
1903 ** Memory changes are now notified using new async record
1905 ** The data-disassemble command response will include a "fullname" field
1906 containing the absolute file name when source has been requested.
1907 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1908 command, to allow pattern filling of memory areas.
1909 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1910 library load/unload events.
1911 ** The response to breakpoint commands and breakpoint async records
1912 includes an "installed" field containing a boolean state about each
1913 non-pending tracepoint location is whether installed on target or not.
1914 ** Output of the "-trace-status" command includes a "trace-file" field
1915 containing the name of the trace file being examined. This field is
1916 optional, and only present when examining a trace file.
1917 ** The "fullname" field is now always present along with the "file" field,
1918 even if the file cannot be found by GDB.
1920 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1921 You must have the LZMA library available when configuring GDB for this
1922 feature to be enabled. For more information, see:
1923 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1925 * New remote packets
1928 Set the size of trace buffer. The remote stub reports support for this
1929 packet to gdb's qSupported query.
1932 Enable Branch Trace Store (BTS)-based branch tracing for the current
1933 thread. The remote stub reports support for this packet to gdb's
1937 Disable branch tracing for the current thread. The remote stub reports
1938 support for this packet to gdb's qSupported query.
1941 Read the traced branches for the current thread. The remote stub
1942 reports support for this packet to gdb's qSupported query.
1944 *** Changes in GDB 7.5
1946 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1947 for more x32 ABI info.
1949 * GDB now supports access to MIPS DSP registers on Linux targets.
1951 * GDB now supports debugging microMIPS binaries.
1953 * The "info os" command on GNU/Linux can now display information on
1954 several new classes of objects managed by the operating system:
1955 "info os procgroups" lists process groups
1956 "info os files" lists file descriptors
1957 "info os sockets" lists internet-domain sockets
1958 "info os shm" lists shared-memory regions
1959 "info os semaphores" lists semaphores
1960 "info os msg" lists message queues
1961 "info os modules" lists loaded kernel modules
1963 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1964 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1965 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1966 options and inspect the probe arguments using the new $_probe_arg family
1967 of convenience variables. You can obtain more information about SystemTap
1968 in <http://sourceware.org/systemtap/>.
1970 * GDB now supports reversible debugging on ARM, it allows you to
1971 debug basic ARM and THUMB instructions, and provides
1972 record/replay support.
1974 * The option "symbol-reloading" has been deleted as it is no longer used.
1978 ** GDB commands implemented in Python can now be put in command class
1981 ** The "maint set python print-stack on|off" is now deleted.
1983 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1984 apply "flag enum"-style pretty-printing to any enum.
1986 ** gdb.lookup_symbol can now work when there is no current frame.
1988 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1989 the source at which the symbol was defined.
1991 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1992 method 'value'. The former indicates whether the symbol needs a
1993 frame in order to compute its value, and the latter computes the
1996 ** A new method 'referenced_value' on gdb.Value objects which can
1997 dereference pointer as well as C++ reference values.
1999 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2000 which return the global and static blocks (as gdb.Block objects),
2001 of the underlying symbol table, respectively.
2003 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2004 object associated with a PC value.
2006 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2007 of the address range occupied by code for the current source line.
2009 * Go language support.
2010 GDB now supports debugging programs written in the Go programming
2013 * GDBserver now supports stdio connections.
2014 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2016 * The binary "gdbtui" can no longer be built or installed.
2017 Use "gdb -tui" instead.
2019 * GDB will now print "flag" enums specially. A flag enum is one where
2020 all the enumerator values have no bits in common when pairwise
2021 "and"ed. When printing a value whose type is a flag enum, GDB will
2022 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2023 (gdb) print (enum E) 3
2026 * The filename part of a linespec will now match trailing components
2027 of a source file name. For example, "break gcc/expr.c:1000" will
2028 now set a breakpoint in build/gcc/expr.c, but not
2029 build/libcpp/expr.c.
2031 * The "info proc" and "generate-core-file" commands will now also
2032 work on remote targets connected to GDBserver on Linux.
2034 * The command "info catch" has been removed. It has been disabled
2035 since December 2007.
2037 * The "catch exception" and "catch assert" commands now accept
2038 a condition at the end of the command, much like the "break"
2039 command does. For instance:
2041 (gdb) catch exception Constraint_Error if Barrier = True
2043 Previously, it was possible to add a condition to such catchpoints,
2044 but it had to be done as a second step, after the catchpoint had been
2045 created, using the "condition" command.
2047 * The "info static-tracepoint-marker" command will now also work on
2048 native Linux targets with in-process agent.
2050 * GDB can now set breakpoints on inlined functions.
2052 * The .gdb_index section has been updated to include symbols for
2053 inlined functions. GDB will ignore older .gdb_index sections by
2054 default, which could cause symbol files to be loaded more slowly
2055 until their .gdb_index sections can be recreated. The new command
2056 "set use-deprecated-index-sections on" will cause GDB to use any older
2057 .gdb_index sections it finds. This will restore performance, but the
2058 ability to set breakpoints on inlined functions will be lost in symbol
2059 files with older .gdb_index sections.
2061 The .gdb_index section has also been updated to record more information
2062 about each symbol. This speeds up the "info variables", "info functions"
2063 and "info types" commands when used with programs having the .gdb_index
2064 section, as well as speeding up debugging with shared libraries using
2065 the .gdb_index section.
2067 * Ada support for GDB/MI Variable Objects has been added.
2069 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2074 ** New command -info-os is the MI equivalent of "info os".
2076 ** Output logs ("set logging" and related) now include MI output.
2080 ** "set use-deprecated-index-sections on|off"
2081 "show use-deprecated-index-sections on|off"
2082 Controls the use of deprecated .gdb_index sections.
2084 ** "catch load" and "catch unload" can be used to stop when a shared
2085 library is loaded or unloaded, respectively.
2087 ** "enable count" can be used to auto-disable a breakpoint after
2090 ** "info vtbl" can be used to show the virtual method tables for
2091 C++ and Java objects.
2093 ** "explore" and its sub commands "explore value" and "explore type"
2094 can be used to recursively explore values and types of
2095 expressions. These commands are available only if GDB is
2096 configured with '--with-python'.
2098 ** "info auto-load" shows status of all kinds of auto-loaded files,
2099 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2100 sequences of commands files, "info auto-load python-scripts"
2101 shows status of auto-loading Python script files,
2102 "info auto-load local-gdbinit" shows status of loading init file
2103 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2104 status of inferior specific thread debugging shared library loading.
2106 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2107 and "show auto-load-scripts" commands have been deprecated, use their
2108 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2109 and "show auto-load python-scripts" counterparts instead.
2111 ** "dprintf location,format,args..." creates a dynamic printf, which
2112 is basically a breakpoint that does a printf and immediately
2113 resumes your program's execution, so it is like a printf that you
2114 can insert dynamically at runtime instead of at compiletime.
2116 ** "set print symbol"
2118 Controls whether GDB attempts to display the symbol, if any,
2119 corresponding to addresses it prints. This defaults to "on", but
2120 you can set it to "off" to restore GDB's previous behavior.
2122 * Deprecated commands
2124 ** For the Renesas Super-H architecture, the "regs" command has been
2125 deprecated, and "info all-registers" should be used instead.
2129 Renesas RL78 rl78-*-elf
2130 HP OpenVMS ia64 ia64-hp-openvms*
2132 * GDBserver supports evaluation of breakpoint conditions. When
2133 support is advertised by GDBserver, GDB may be told to send the
2134 breakpoint conditions in bytecode form to GDBserver. GDBserver
2135 will only report the breakpoint trigger to GDB when its condition
2140 set mips compression
2141 show mips compression
2142 Select the compressed ISA encoding used in functions that have no symbol
2143 information available. The encoding can be set to either of:
2146 and is updated automatically from ELF file flags if available.
2148 set breakpoint condition-evaluation
2149 show breakpoint condition-evaluation
2150 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2151 GDBserver ("target"). Default option "auto" chooses the most efficient
2153 This option can improve debugger efficiency depending on the speed of the
2157 Disable auto-loading globally.
2160 Show auto-loading setting of all kinds of auto-loaded files.
2162 set auto-load gdb-scripts on|off
2163 show auto-load gdb-scripts
2164 Control auto-loading of GDB canned sequences of commands files.
2166 set auto-load python-scripts on|off
2167 show auto-load python-scripts
2168 Control auto-loading of Python script files.
2170 set auto-load local-gdbinit on|off
2171 show auto-load local-gdbinit
2172 Control loading of init file (.gdbinit) from current directory.
2174 set auto-load libthread-db on|off
2175 show auto-load libthread-db
2176 Control auto-loading of inferior specific thread debugging shared library.
2178 set auto-load scripts-directory <dir1>[:<dir2>...]
2179 show auto-load scripts-directory
2180 Set a list of directories from which to load auto-loaded scripts.
2181 Automatically loaded Python scripts and GDB scripts are located in one
2182 of the directories listed by this option.
2183 The delimiter (':' above) may differ according to the host platform.
2185 set auto-load safe-path <dir1>[:<dir2>...]
2186 show auto-load safe-path
2187 Set a list of directories from which it is safe to auto-load files.
2188 The delimiter (':' above) may differ according to the host platform.
2190 set debug auto-load on|off
2191 show debug auto-load
2192 Control display of debugging info for auto-loading the files above.
2194 set dprintf-style gdb|call|agent
2196 Control the way in which a dynamic printf is performed; "gdb"
2197 requests a GDB printf command, while "call" causes dprintf to call a
2198 function in the inferior. "agent" requests that the target agent
2199 (such as GDBserver) do the printing.
2201 set dprintf-function <expr>
2202 show dprintf-function
2203 set dprintf-channel <expr>
2204 show dprintf-channel
2205 Set the function and optional first argument to the call when using
2206 the "call" style of dynamic printf.
2208 set disconnected-dprintf on|off
2209 show disconnected-dprintf
2210 Control whether agent-style dynamic printfs continue to be in effect
2211 after GDB disconnects.
2213 * New configure options
2215 --with-auto-load-dir
2216 Configure default value for the 'set auto-load scripts-directory'
2217 setting above. It defaults to '$debugdir:$datadir/auto-load',
2218 $debugdir representing global debugging info directories (available
2219 via 'show debug-file-directory') and $datadir representing GDB's data
2220 directory (available via 'show data-directory').
2222 --with-auto-load-safe-path
2223 Configure default value for the 'set auto-load safe-path' setting
2224 above. It defaults to the --with-auto-load-dir setting.
2226 --without-auto-load-safe-path
2227 Set 'set auto-load safe-path' to '/', effectively disabling this
2230 * New remote packets
2232 z0/z1 conditional breakpoints extension
2234 The z0/z1 breakpoint insertion packets have been extended to carry
2235 a list of conditional expressions over to the remote stub depending on the
2236 condition evaluation mode. The use of this extension can be controlled
2237 via the "set remote conditional-breakpoints-packet" command.
2241 Specify the signals which the remote stub may pass to the debugged
2242 program without GDB involvement.
2244 * New command line options
2246 --init-command=FILE, -ix Like --command, -x but execute it
2247 before loading inferior.
2248 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2249 execute it before loading inferior.
2251 *** Changes in GDB 7.4
2253 * GDB now handles ambiguous linespecs more consistently; the existing
2254 FILE:LINE support has been expanded to other types of linespecs. A
2255 breakpoint will now be set on all matching locations in all
2256 inferiors, and locations will be added or removed according to
2259 * GDB now allows you to skip uninteresting functions and files when
2260 stepping with the "skip function" and "skip file" commands.
2262 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2263 and "show remote hardware-watchpoint-length-limit". These allows to
2264 set or show the maximum length limit (in bytes) of a remote
2265 target hardware watchpoint.
2267 This allows e.g. to use "unlimited" hardware watchpoints with the
2268 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2269 watchpoints are slower than real hardware watchpoints but are
2270 significantly faster than gdb software watchpoints.
2274 ** The register_pretty_printer function in module gdb.printing now takes
2275 an optional `replace' argument. If True, the new printer replaces any
2278 ** The "maint set python print-stack on|off" command has been
2279 deprecated and will be deleted in GDB 7.5.
2280 A new command: "set python print-stack none|full|message" has
2281 replaced it. Additionally, the default for "print-stack" is
2282 now "message", which just prints the error message without
2285 ** A prompt substitution hook (prompt_hook) is now available to the
2288 ** A new Python module, gdb.prompt has been added to the GDB Python
2289 modules library. This module provides functionality for
2290 escape sequences in prompts (used by set/show
2291 extended-prompt). These escape sequences are replaced by their
2292 corresponding value.
2294 ** Python commands and convenience-functions located in
2295 'data-directory'/python/gdb/command and
2296 'data-directory'/python/gdb/function are now automatically loaded
2299 ** Blocks now provide four new attributes. global_block and
2300 static_block will return the global and static blocks
2301 respectively. is_static and is_global are boolean attributes
2302 that indicate if the block is one of those two types.
2304 ** Symbols now provide the "type" attribute, the type of the symbol.
2306 ** The "gdb.breakpoint" function has been deprecated in favor of
2309 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2310 of a function. This class is based on the "finish" command
2311 available in the CLI.
2313 ** Type objects for struct and union types now allow access to
2314 the fields using standard Python dictionary (mapping) methods.
2315 For example, "some_type['myfield']" now works, as does
2316 "some_type.items()".
2318 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2321 ** A new function, "deep_items" has been added to the gdb.types
2322 module in the GDB Python modules library. This function returns
2323 an iterator over the fields of a struct or union type. Unlike
2324 the standard Python "iteritems" method, it will recursively traverse
2325 any anonymous fields.
2329 ** "*stopped" events can report several new "reason"s, such as
2332 ** Breakpoint changes are now notified using new async records, like
2333 "=breakpoint-modified".
2335 ** New command -ada-task-info.
2337 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2338 $sdir specifies the default system locations of shared libraries.
2339 $pdir specifies the directory where the libpthread used by the application
2342 GDB no longer looks in $sdir and $pdir after it has searched the directories
2343 mentioned in libthread-db-search-path. If you want to search those
2344 directories, they must be specified in libthread-db-search-path.
2345 The default value of libthread-db-search-path on GNU/Linux and Solaris
2346 systems is now "$sdir:$pdir".
2348 $pdir is not supported by gdbserver, it is currently ignored.
2349 $sdir is supported by gdbserver.
2351 * New configure option --with-iconv-bin.
2352 When using the internationalization support like the one in the GNU C
2353 library, GDB will invoke the "iconv" program to get a list of supported
2354 character sets. If this program lives in a non-standard location, one can
2355 use this option to specify where to find it.
2357 * When natively debugging programs on PowerPC BookE processors running
2358 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2359 watchpoints, which specify a mask in addition to an address to watch.
2360 The mask specifies that some bits of an address (the bits which are
2361 reset in the mask) should be ignored when matching the address accessed
2362 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2363 section in the user manual for more details.
2365 * The new option --once causes GDBserver to stop listening for connections once
2366 the first connection is made. The listening port used by GDBserver will
2367 become available after that.
2369 * New commands "info macros" and "alias" have been added.
2371 * New function parameters suffix @entry specifies value of function parameter
2372 at the time the function got called. Entry values are available only since
2378 "!" is now an alias of the "shell" command.
2379 Note that no space is needed between "!" and SHELL COMMAND.
2383 watch EXPRESSION mask MASK_VALUE
2384 The watch command now supports the mask argument which allows creation
2385 of masked watchpoints, if the current architecture supports this feature.
2387 info auto-load-scripts [REGEXP]
2388 This command was formerly named "maintenance print section-scripts".
2389 It is now generally useful and is no longer a maintenance-only command.
2391 info macro [-all] [--] MACRO
2392 The info macro command has new options `-all' and `--'. The first for
2393 printing all definitions of a macro. The second for explicitly specifying
2394 the end of arguments and the beginning of the macro name in case the macro
2395 name starts with a hyphen.
2397 collect[/s] EXPRESSIONS
2398 The tracepoint collect command now takes an optional modifier "/s"
2399 that directs it to dereference pointer-to-character types and
2400 collect the bytes of memory up to a zero byte. The behavior is
2401 similar to what you see when you use the regular print command on a
2402 string. An optional integer following the "/s" sets a bound on the
2403 number of bytes that will be collected.
2406 The trace start command now interprets any supplied arguments as a
2407 note to be recorded with the trace run, with an effect similar to
2408 setting the variable trace-notes.
2411 The trace stop command now interprets any arguments as a note to be
2412 mentioned along with the tstatus report that the trace was stopped
2413 with a command. The effect is similar to setting the variable
2416 * Tracepoints can now be enabled and disabled at any time after a trace
2417 experiment has been started using the standard "enable" and "disable"
2418 commands. It is now possible to start a trace experiment with no enabled
2419 tracepoints; GDB will display a warning, but will allow the experiment to
2420 begin, assuming that tracepoints will be enabled as needed while the trace
2423 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2424 locations with 4-byte instructions, when they were previously
2425 limited to locations with instructions of 5 bytes or longer.
2429 set debug dwarf2-read
2430 show debug dwarf2-read
2431 Turns on or off display of debugging messages related to reading
2432 DWARF debug info. The default is off.
2434 set debug symtab-create
2435 show debug symtab-create
2436 Turns on or off display of debugging messages related to symbol table
2437 creation. The default is off.
2440 show extended-prompt
2441 Set the GDB prompt, and allow escape sequences to be inserted to
2442 display miscellaneous information (see 'help set extended-prompt'
2443 for the list of sequences). This prompt (and any information
2444 accessed through the escape sequences) is updated every time the
2445 prompt is displayed.
2447 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2448 show print entry-values
2449 Set printing of frame argument values at function entry. In some cases
2450 GDB can determine the value of function argument which was passed by the
2451 function caller, even if the value was modified inside the called function.
2453 set debug entry-values
2454 show debug entry-values
2455 Control display of debugging info for determining frame argument values at
2456 function entry and virtual tail call frames.
2458 set basenames-may-differ
2459 show basenames-may-differ
2460 Set whether a source file may have multiple base names.
2461 (A "base name" is the name of a file with the directory part removed.
2462 Example: The base name of "/home/user/hello.c" is "hello.c".)
2463 If set, GDB will canonicalize file names (e.g., expand symlinks)
2464 before comparing them. Canonicalization is an expensive operation,
2465 but it allows the same file be known by more than one base name.
2466 If not set (the default), all source files are assumed to have just
2467 one base name, and gdb will do file name comparisons more efficiently.
2473 Set a user name and notes for the current and any future trace runs.
2474 This is useful for long-running and/or disconnected traces, to
2475 inform others (or yourself) as to who is running the trace, supply
2476 contact information, or otherwise explain what is going on.
2478 set trace-stop-notes
2479 show trace-stop-notes
2480 Set a note attached to the trace run, that is displayed when the
2481 trace has been stopped by a tstop command. This is useful for
2482 instance as an explanation, if you are stopping a trace run that was
2483 started by someone else.
2485 * New remote packets
2489 Dynamically enable a tracepoint in a started trace experiment.
2493 Dynamically disable a tracepoint in a started trace experiment.
2497 Set the user and notes of the trace run.
2501 Query the current status of a tracepoint.
2505 Query the minimum length of instruction at which a fast tracepoint may
2508 * Dcache size (number of lines) and line-size are now runtime-configurable
2509 via "set dcache line" and "set dcache line-size" commands.
2513 Texas Instruments TMS320C6x tic6x-*-*
2517 Renesas RL78 rl78-*-elf
2519 *** Changes in GDB 7.3.1
2521 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2523 *** Changes in GDB 7.3
2525 * GDB has a new command: "thread find [REGEXP]".
2526 It finds the thread id whose name, target id, or thread extra info
2527 matches the given regular expression.
2529 * The "catch syscall" command now works on mips*-linux* targets.
2531 * The -data-disassemble MI command now supports modes 2 and 3 for
2532 dumping the instruction opcodes.
2534 * New command line options
2536 -data-directory DIR Specify DIR as the "data-directory".
2537 This is mostly for testing purposes.
2539 * The "maint set python auto-load on|off" command has been renamed to
2540 "set auto-load-scripts on|off".
2542 * GDB has a new command: "set directories".
2543 It is like the "dir" command except that it replaces the
2544 source path list instead of augmenting it.
2546 * GDB now understands thread names.
2548 On GNU/Linux, "info threads" will display the thread name as set by
2549 prctl or pthread_setname_np.
2551 There is also a new command, "thread name", which can be used to
2552 assign a name internally for GDB to display.
2555 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2556 has been integrated into GDB.
2560 ** The function gdb.Write now accepts an optional keyword 'stream'.
2561 This keyword, when provided, will direct the output to either
2562 stdout, stderr, or GDB's logging output.
2564 ** Parameters can now be be sub-classed in Python, and in particular
2565 you may implement the get_set_doc and get_show_doc functions.
2566 This improves how Parameter set/show documentation is processed
2567 and allows for more dynamic content.
2569 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2570 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2571 have an is_valid method.
2573 ** Breakpoints can now be sub-classed in Python, and in particular
2574 you may implement a 'stop' function that is executed each time
2575 the inferior reaches that breakpoint.
2577 ** New function gdb.lookup_global_symbol looks up a global symbol.
2579 ** GDB values in Python are now callable if the value represents a
2580 function. For example, if 'some_value' represents a function that
2581 takes two integer parameters and returns a value, you can call
2582 that function like so:
2584 result = some_value (10,20)
2586 ** Module gdb.types has been added.
2587 It contains a collection of utilities for working with gdb.Types objects:
2588 get_basic_type, has_field, make_enum_dict.
2590 ** Module gdb.printing has been added.
2591 It contains utilities for writing and registering pretty-printers.
2592 New classes: PrettyPrinter, SubPrettyPrinter,
2593 RegexpCollectionPrettyPrinter.
2594 New function: register_pretty_printer.
2596 ** New commands "info pretty-printers", "enable pretty-printer" and
2597 "disable pretty-printer" have been added.
2599 ** gdb.parameter("directories") is now available.
2601 ** New function gdb.newest_frame returns the newest frame in the
2604 ** The gdb.InferiorThread class has a new "name" attribute. This
2605 holds the thread's name.
2607 ** Python Support for Inferior events.
2608 Python scripts can add observers to be notified of events
2609 occurring in the process being debugged.
2610 The following events are currently supported:
2611 - gdb.events.cont Continue event.
2612 - gdb.events.exited Inferior exited event.
2613 - gdb.events.stop Signal received, and Breakpoint hit events.
2617 ** GDB now puts template parameters in scope when debugging in an
2618 instantiation. For example, if you have:
2620 template<int X> int func (void) { return X; }
2622 then if you step into func<5>, "print X" will show "5". This
2623 feature requires proper debuginfo support from the compiler; it
2624 was added to GCC 4.5.
2626 ** The motion commands "next", "finish", "until", and "advance" now
2627 work better when exceptions are thrown. In particular, GDB will
2628 no longer lose control of the inferior; instead, the GDB will
2629 stop the inferior at the point at which the exception is caught.
2630 This functionality requires a change in the exception handling
2631 code that was introduced in GCC 4.5.
2633 * GDB now follows GCC's rules on accessing volatile objects when
2634 reading or writing target state during expression evaluation.
2635 One notable difference to prior behavior is that "print x = 0"
2636 no longer generates a read of x; the value of the assignment is
2637 now always taken directly from the value being assigned.
2639 * GDB now has some support for using labels in the program's source in
2640 linespecs. For instance, you can use "advance label" to continue
2641 execution to a label.
2643 * GDB now has support for reading and writing a new .gdb_index
2644 section. This section holds a fast index of DWARF debugging
2645 information and can be used to greatly speed up GDB startup and
2646 operation. See the documentation for `save gdb-index' for details.
2648 * The "watch" command now accepts an optional "-location" argument.
2649 When used, this causes GDB to watch the memory referred to by the
2650 expression. Such a watchpoint is never deleted due to it going out
2653 * GDB now supports thread debugging of core dumps on GNU/Linux.
2655 GDB now activates thread debugging using the libthread_db library
2656 when debugging GNU/Linux core dumps, similarly to when debugging
2657 live processes. As a result, when debugging a core dump file, GDB
2658 is now able to display pthread_t ids of threads. For example, "info
2659 threads" shows the same output as when debugging the process when it
2660 was live. In earlier releases, you'd see something like this:
2663 * 1 LWP 6780 main () at main.c:10
2665 While now you see this:
2668 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2670 It is also now possible to inspect TLS variables when debugging core
2673 When debugging a core dump generated on a machine other than the one
2674 used to run GDB, you may need to point GDB at the correct
2675 libthread_db library with the "set libthread-db-search-path"
2676 command. See the user manual for more details on this command.
2678 * When natively debugging programs on PowerPC BookE processors running
2679 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2680 which stop execution of the inferior whenever it executes an instruction
2681 at any address within the specified range. See the "PowerPC Embedded"
2682 section in the user manual for more details.
2684 * New features in the GDB remote stub, GDBserver
2686 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2687 and i686 LynxOS (version 5.x).
2689 ** GDBserver is now supported on Blackfin Linux.
2691 * New native configurations
2693 ia64 HP-UX ia64-*-hpux*
2697 Analog Devices, Inc. Blackfin Processor bfin-*
2699 * Ada task switching is now supported on sparc-elf targets when
2700 debugging a program using the Ravenscar Profile. For more information,
2701 see the "Tasking Support when using the Ravenscar Profile" section
2702 in the GDB user manual.
2704 * Guile support was removed.
2706 * New features in the GNU simulator
2708 ** The --map-info flag lists all known core mappings.
2710 ** CFI flashes may be simulated via the "cfi" device.
2712 *** Changes in GDB 7.2
2714 * Shared library support for remote targets by default
2716 When GDB is configured for a generic, non-OS specific target, like
2717 for example, --target=arm-eabi or one of the many *-*-elf targets,
2718 GDB now queries remote stubs for loaded shared libraries using the
2719 `qXfer:libraries:read' packet. Previously, shared library support
2720 was always disabled for such configurations.
2724 ** Argument Dependent Lookup (ADL)
2726 In C++ ADL lookup directs function search to the namespaces of its
2727 arguments even if the namespace has not been imported.
2737 Here the compiler will search for `foo' in the namespace of 'b'
2738 and find A::foo. GDB now supports this. This construct is commonly
2739 used in the Standard Template Library for operators.
2741 ** Improved User Defined Operator Support
2743 In addition to member operators, GDB now supports lookup of operators
2744 defined in a namespace and imported with a `using' directive, operators
2745 defined in the global scope, operators imported implicitly from an
2746 anonymous namespace, and the ADL operators mentioned in the previous
2748 GDB now also supports proper overload resolution for all the previously
2749 mentioned flavors of operators.
2751 ** static const class members
2753 Printing of static const class members that are initialized in the
2754 class definition has been fixed.
2756 * Windows Thread Information Block access.
2758 On Windows targets, GDB now supports displaying the Windows Thread
2759 Information Block (TIB) structure. This structure is visible either
2760 by using the new command `info w32 thread-information-block' or, by
2761 dereferencing the new convenience variable named `$_tlb', a
2762 thread-specific pointer to the TIB. This feature is also supported
2763 when remote debugging using GDBserver.
2765 * Static tracepoints
2767 Static tracepoints are calls in the user program into a tracing
2768 library. One such library is a port of the LTTng kernel tracer to
2769 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2770 When debugging with GDBserver, GDB now supports combining the GDB
2771 tracepoint machinery with such libraries. For example: the user can
2772 use GDB to probe a static tracepoint marker (a call from the user
2773 program into the tracing library) with the new "strace" command (see
2774 "New commands" below). This creates a "static tracepoint" in the
2775 breakpoint list, that can be manipulated with the same feature set
2776 as fast and regular tracepoints. E.g., collect registers, local and
2777 global variables, collect trace state variables, and define
2778 tracepoint conditions. In addition, the user can collect extra
2779 static tracepoint marker specific data, by collecting the new
2780 $_sdata internal variable. When analyzing the trace buffer, you can
2781 inspect $_sdata like any other variable available to GDB. For more
2782 information, see the "Tracepoints" chapter in GDB user manual. New
2783 remote packets have been defined to support static tracepoints, see
2784 the "New remote packets" section below.
2786 * Better reconstruction of tracepoints after disconnected tracing
2788 GDB will attempt to download the original source form of tracepoint
2789 definitions when starting a trace run, and then will upload these
2790 upon reconnection to the target, resulting in a more accurate
2791 reconstruction of the tracepoints that are in use on the target.
2795 You can now exercise direct control over the ways that GDB can
2796 affect your program. For instance, you can disallow the setting of
2797 breakpoints, so that the program can run continuously (assuming
2798 non-stop mode). In addition, the "observer" variable is available
2799 to switch all of the different controls; in observer mode, GDB
2800 cannot affect the target's behavior at all, which is useful for
2801 tasks like diagnosing live systems in the field.
2803 * The new convenience variable $_thread holds the number of the
2806 * New remote packets
2810 Return the address of the Windows Thread Information Block of a given thread.
2814 In response to several of the tracepoint packets, the target may now
2815 also respond with a number of intermediate `qRelocInsn' request
2816 packets before the final result packet, to have GDB handle
2817 relocating an instruction to execute at a different address. This
2818 is particularly useful for stubs that support fast tracepoints. GDB
2819 reports support for this feature in the qSupported packet.
2823 List static tracepoint markers in the target program.
2827 List static tracepoint markers at a given address in the target
2830 qXfer:statictrace:read
2832 Read the static trace data collected (by a `collect $_sdata'
2833 tracepoint action). The remote stub reports support for this packet
2834 to gdb's qSupported query.
2838 Send the current settings of GDB's permission flags.
2842 Send part of the source (textual) form of a tracepoint definition,
2843 which includes location, conditional, and action list.
2845 * The source command now accepts a -s option to force searching for the
2846 script in the source search path even if the script name specifies
2849 * New features in the GDB remote stub, GDBserver
2851 - GDBserver now support tracepoints (including fast tracepoints, and
2852 static tracepoints). The feature is currently supported by the
2853 i386-linux and amd64-linux builds. See the "Tracepoints support
2854 in gdbserver" section in the manual for more information.
2856 GDBserver JIT compiles the tracepoint's conditional agent
2857 expression bytecode into native code whenever possible for low
2858 overhead dynamic tracepoints conditionals. For such tracepoints,
2859 an expression that examines program state is evaluated when the
2860 tracepoint is reached, in order to determine whether to capture
2861 trace data. If the condition is simple and false, processing the
2862 tracepoint finishes very quickly and no data is gathered.
2864 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2865 for static tracepoints support.
2867 - GDBserver now supports x86_64 Windows 64-bit debugging.
2869 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2870 it understands register description.
2872 * The --batch flag now disables pagination and queries.
2874 * X86 general purpose registers
2876 GDB now supports reading/writing byte, word and double-word x86
2877 general purpose registers directly. This means you can use, say,
2878 $ah or $ax to refer, respectively, to the byte register AH and
2879 16-bit word register AX that are actually portions of the 32-bit
2880 register EAX or 64-bit register RAX.
2882 * The `commands' command now accepts a range of breakpoints to modify.
2883 A plain `commands' following a command that creates multiple
2884 breakpoints affects all the breakpoints set by that command. This
2885 applies to breakpoints set by `rbreak', and also applies when a
2886 single `break' command creates multiple breakpoints (e.g.,
2887 breakpoints on overloaded c++ functions).
2889 * The `rbreak' command now accepts a filename specification as part of
2890 its argument, limiting the functions selected by the regex to those
2891 in the specified file.
2893 * Support for remote debugging Windows and SymbianOS shared libraries
2894 from Unix hosts has been improved. Non Windows GDB builds now can
2895 understand target reported file names that follow MS-DOS based file
2896 system semantics, such as file names that include drive letters and
2897 use the backslash character as directory separator. This makes it
2898 possible to transparently use the "set sysroot" and "set
2899 solib-search-path" on Unix hosts to point as host copies of the
2900 target's shared libraries. See the new command "set
2901 target-file-system-kind" described below, and the "Commands to
2902 specify files" section in the user manual for more information.
2906 eval template, expressions...
2907 Convert the values of one or more expressions under the control
2908 of the string template to a command line, and call it.
2910 set target-file-system-kind unix|dos-based|auto
2911 show target-file-system-kind
2912 Set or show the assumed file system kind for target reported file
2915 save breakpoints <filename>
2916 Save all current breakpoint definitions to a file suitable for use
2917 in a later debugging session. To read the saved breakpoint
2918 definitions, use the `source' command.
2920 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2923 info static-tracepoint-markers
2924 Display information about static tracepoint markers in the target.
2926 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2927 Define a static tracepoint by probing a marker at the given
2928 function, line, address, or marker ID.
2932 Enable and disable observer mode.
2934 set may-write-registers on|off
2935 set may-write-memory on|off
2936 set may-insert-breakpoints on|off
2937 set may-insert-tracepoints on|off
2938 set may-insert-fast-tracepoints on|off
2939 set may-interrupt on|off
2940 Set individual permissions for GDB effects on the target. Note that
2941 some of these settings can have undesirable or surprising
2942 consequences, particularly when changed in the middle of a session.
2943 For instance, disabling the writing of memory can prevent
2944 breakpoints from being inserted, cause single-stepping to fail, or
2945 even crash your program, if you disable after breakpoints have been
2946 inserted. However, GDB should not crash.
2948 set record memory-query on|off
2949 show record memory-query
2950 Control whether to stop the inferior if memory changes caused
2951 by an instruction cannot be recorded.
2956 The disassemble command now supports "start,+length" form of two arguments.
2960 ** GDB now provides a new directory location, called the python directory,
2961 where Python scripts written for GDB can be installed. The location
2962 of that directory is <data-directory>/python, where <data-directory>
2963 is the GDB data directory. For more details, see section `Scripting
2964 GDB using Python' in the manual.
2966 ** The GDB Python API now has access to breakpoints, symbols, symbol
2967 tables, program spaces, inferiors, threads and frame's code blocks.
2968 Additionally, GDB Parameters can now be created from the API, and
2969 manipulated via set/show in the CLI.
2971 ** New functions gdb.target_charset, gdb.target_wide_charset,
2972 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2974 ** New exception gdb.GdbError.
2976 ** Pretty-printers are now also looked up in the current program space.
2978 ** Pretty-printers can now be individually enabled and disabled.
2980 ** GDB now looks for names of Python scripts to auto-load in a
2981 special section named `.debug_gdb_scripts', in addition to looking
2982 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2984 * Tracepoint actions were unified with breakpoint commands. In particular,
2985 there are no longer differences in "info break" output for breakpoints and
2986 tracepoints and the "commands" command can be used for both tracepoints and
2987 regular breakpoints.
2991 ARM Symbian arm*-*-symbianelf*
2993 * D language support.
2994 GDB now supports debugging programs written in the D programming
2997 * GDB now supports the extended ptrace interface for PowerPC which is
2998 available since Linux kernel version 2.6.34. This automatically enables
2999 any hardware breakpoints and additional hardware watchpoints available in
3000 the processor. The old ptrace interface exposes just one hardware
3001 watchpoint and no hardware breakpoints.
3003 * GDB is now able to use the Data Value Compare (DVC) register available on
3004 embedded PowerPC processors to implement in hardware simple watchpoint
3005 conditions of the form:
3007 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3009 This works in native GDB running on Linux kernels with the extended ptrace
3010 interface mentioned above.
3012 *** Changes in GDB 7.1
3016 ** Namespace Support
3018 GDB now supports importing of namespaces in C++. This enables the
3019 user to inspect variables from imported namespaces. Support for
3020 namepace aliasing has also been added. So, if a namespace is
3021 aliased in the current scope (e.g. namepace C=A; ) the user can
3022 print variables using the alias (e.g. (gdb) print C::x).
3026 All known bugs relating to the printing of virtual base class were
3027 fixed. It is now possible to call overloaded static methods using a
3032 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3033 and reinterpret_cast<> are now handled by the C++ expression parser.
3037 Xilinx MicroBlaze microblaze-*-*
3042 Xilinx MicroBlaze microblaze
3045 * Multi-program debugging.
3047 GDB now has support for multi-program (a.k.a. multi-executable or
3048 multi-exec) debugging. This allows for debugging multiple inferiors
3049 simultaneously each running a different program under the same GDB
3050 session. See "Debugging Multiple Inferiors and Programs" in the
3051 manual for more information. This implied some user visible changes
3052 in the multi-inferior support. For example, "info inferiors" now
3053 lists inferiors that are not running yet or that have exited
3054 already. See also "New commands" and "New options" below.
3056 * New tracing features
3058 GDB's tracepoint facility now includes several new features:
3060 ** Trace state variables
3062 GDB tracepoints now include support for trace state variables, which
3063 are variables managed by the target agent during a tracing
3064 experiment. They are useful for tracepoints that trigger each
3065 other, so for instance one tracepoint can count hits in a variable,
3066 and then a second tracepoint has a condition that is true when the
3067 count reaches a particular value. Trace state variables share the
3068 $-syntax of GDB convenience variables, and can appear in both
3069 tracepoint actions and condition expressions. Use the "tvariable"
3070 command to create, and "info tvariables" to view; see "Trace State
3071 Variables" in the manual for more detail.
3075 GDB now includes an option for defining fast tracepoints, which
3076 targets may implement more efficiently, such as by installing a jump
3077 into the target agent rather than a trap instruction. The resulting
3078 speedup can be by two orders of magnitude or more, although the
3079 tradeoff is that some program locations on some target architectures
3080 might not allow fast tracepoint installation, for instance if the
3081 instruction to be replaced is shorter than the jump. To request a
3082 fast tracepoint, use the "ftrace" command, with syntax identical to
3083 the regular trace command.
3085 ** Disconnected tracing
3087 It is now possible to detach GDB from the target while it is running
3088 a trace experiment, then reconnect later to see how the experiment
3089 is going. In addition, a new variable disconnected-tracing lets you
3090 tell the target agent whether to continue running a trace if the
3091 connection is lost unexpectedly.
3095 GDB now has the ability to save the trace buffer into a file, and
3096 then use that file as a target, similarly to you can do with
3097 corefiles. You can select trace frames, print data that was
3098 collected in them, and use tstatus to display the state of the
3099 tracing run at the moment that it was saved. To create a trace
3100 file, use "tsave <filename>", and to use it, do "target tfile
3103 ** Circular trace buffer
3105 You can ask the target agent to handle the trace buffer as a
3106 circular buffer, discarding the oldest trace frames to make room for
3107 newer ones, by setting circular-trace-buffer to on. This feature may
3108 not be available for all target agents.
3113 The disassemble command, when invoked with two arguments, now requires
3114 the arguments to be comma-separated.
3117 The info variables command now displays variable definitions. Files
3118 which only declare a variable are not shown.
3121 The source command is now capable of sourcing Python scripts.
3122 This feature is dependent on the debugger being build with Python
3125 Related to this enhancement is also the introduction of a new command
3126 "set script-extension" (see below).
3128 * New commands (for set/show, see "New options" below)
3130 record save [<FILENAME>]
3131 Save a file (in core file format) containing the process record
3132 execution log for replay debugging at a later time.
3134 record restore <FILENAME>
3135 Restore the process record execution log that was saved at an
3136 earlier time, for replay debugging.
3138 add-inferior [-copies <N>] [-exec <FILENAME>]
3141 clone-inferior [-copies <N>] [ID]
3142 Make a new inferior ready to execute the same program another
3143 inferior has loaded.
3148 maint info program-spaces
3149 List the program spaces loaded into GDB.
3151 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3152 show remote interrupt-sequence
3153 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3154 as the sequence to the remote target in order to interrupt the execution.
3155 Ctrl-C is a default. Some system prefers BREAK which is high level of
3156 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3157 Magic SysRq g. It is BREAK signal and character 'g'.
3159 set remote interrupt-on-connect [on | off]
3160 show remote interrupt-on-connect
3161 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3162 remote target when gdb connects to it. This is needed when you debug
3165 set remotebreak [on | off]
3167 Deprecated. Use "set/show remote interrupt-sequence" instead.
3169 tvariable $NAME [ = EXP ]
3170 Create or modify a trace state variable.
3173 List trace state variables and their values.
3175 delete tvariable $NAME ...
3176 Delete one or more trace state variables.
3179 Evaluate the given expressions without collecting anything into the
3180 trace buffer. (Valid in tracepoint actions only.)
3182 ftrace FN / FILE:LINE / *ADDR
3183 Define a fast tracepoint at the given function, line, or address.
3185 * New expression syntax
3187 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3188 GDB now parses 0b101010 identically with 42.
3192 set follow-exec-mode new|same
3193 show follow-exec-mode
3194 Control whether GDB reuses the same inferior across an exec call or
3195 creates a new one. This is useful to be able to restart the old
3196 executable after the inferior having done an exec call.
3198 set default-collect EXPR, ...
3199 show default-collect
3200 Define a list of expressions to be collected at each tracepoint.
3201 This is a useful way to ensure essential items are not overlooked,
3202 such as registers or a critical global variable.
3204 set disconnected-tracing
3205 show disconnected-tracing
3206 If set to 1, the target is instructed to continue tracing if it
3207 loses its connection to GDB. If 0, the target is to stop tracing
3210 set circular-trace-buffer
3211 show circular-trace-buffer
3212 If set to on, the target is instructed to use a circular trace buffer
3213 and discard the oldest trace frames instead of stopping the trace due
3214 to a full trace buffer. If set to off, the trace stops when the buffer
3215 fills up. Some targets may not support this.
3217 set script-extension off|soft|strict
3218 show script-extension
3219 If set to "off", the debugger does not perform any script language
3220 recognition, and all sourced files are assumed to be GDB scripts.
3221 If set to "soft" (the default), files are sourced according to
3222 filename extension, falling back to GDB scripts if the first
3224 If set to "strict", files are sourced according to filename extension.
3226 set ada trust-PAD-over-XVS on|off
3227 show ada trust-PAD-over-XVS
3228 If off, activate a workaround against a bug in the debugging information
3229 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3230 the GCC sources for more information about the GNAT encoding and
3231 PAD types in particular). It is always safe to set this option to
3232 off, but this introduces a slight performance penalty. The default
3235 * Python API Improvements
3237 ** GDB provides the new class gdb.LazyString. This is useful in
3238 some pretty-printing cases. The new method gdb.Value.lazy_string
3239 provides a simple way to create objects of this type.
3241 ** The fields returned by gdb.Type.fields now have an
3242 `is_base_class' attribute.
3244 ** The new method gdb.Type.range returns the range of an array type.
3246 ** The new method gdb.parse_and_eval can be used to parse and
3247 evaluate an expression.
3249 * New remote packets
3252 Define a trace state variable.
3255 Get the current value of a trace state variable.
3258 Set desired tracing behavior upon disconnection.
3261 Set the trace buffer to be linear or circular.
3264 Get data about the tracepoints currently in use.
3268 Process record now works correctly with hardware watchpoints.
3270 Multiple bug fixes have been made to the mips-irix port, making it
3271 much more reliable. In particular:
3272 - Debugging threaded applications is now possible again. Previously,
3273 GDB would hang while starting the program, or while waiting for
3274 the program to stop at a breakpoint.
3275 - Attaching to a running process no longer hangs.
3276 - An error occurring while loading a core file has been fixed.
3277 - Changing the value of the PC register now works again. This fixes
3278 problems observed when using the "jump" command, or when calling
3279 a function from GDB, or even when assigning a new value to $pc.
3280 - With the "finish" and "return" commands, the return value for functions
3281 returning a small array is now correctly printed.
3282 - It is now possible to break on shared library code which gets executed
3283 during a shared library init phase (code executed while executing
3284 their .init section). Previously, the breakpoint would have no effect.
3285 - GDB is now able to backtrace through the signal handler for
3286 non-threaded programs.
3288 PIE (Position Independent Executable) programs debugging is now supported.
3289 This includes debugging execution of PIC (Position Independent Code) shared
3290 libraries although for that, it should be possible to run such libraries as an
3293 *** Changes in GDB 7.0
3295 * GDB now has an interface for JIT compilation. Applications that
3296 dynamically generate code can create symbol files in memory and register
3297 them with GDB. For users, the feature should work transparently, and
3298 for JIT developers, the interface is documented in the GDB manual in the
3299 "JIT Compilation Interface" chapter.
3301 * Tracepoints may now be conditional. The syntax is as for
3302 breakpoints; either an "if" clause appended to the "trace" command,
3303 or the "condition" command is available. GDB sends the condition to
3304 the target for evaluation using the same bytecode format as is used
3305 for tracepoint actions.
3307 * The disassemble command now supports: an optional /r modifier, print the
3308 raw instructions in hex as well as in symbolic form, and an optional /m
3309 modifier to print mixed source+assembly.
3311 * Process record and replay
3313 In a architecture environment that supports ``process record and
3314 replay'', ``process record and replay'' target can record a log of
3315 the process execution, and replay it with both forward and reverse
3318 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3319 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3320 set execution-direction {forward|reverse}, for targets that support
3323 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3324 feature is available with a native GDB running on kernel version
3327 * GDB now has support for multi-byte and wide character sets on the
3328 target. Strings whose character type is wchar_t, char16_t, or
3329 char32_t are now correctly printed. GDB supports wide- and unicode-
3330 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3331 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3332 `printf'. This feature requires iconv to work properly; if your
3333 system does not have a working iconv, GDB can use GNU libiconv. See
3334 the installation instructions for more information.
3336 * GDB now supports automatic retrieval of shared library files from
3337 remote targets. To use this feature, specify a system root that begins
3338 with the `remote:' prefix, either via the `set sysroot' command or via
3339 the `--with-sysroot' configure-time option.
3341 * "info sharedlibrary" now takes an optional regex of libraries to show,
3342 and it now reports if a shared library has no debugging information.
3344 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3345 now complete on file names.
3347 * When completing in expressions, gdb will attempt to limit
3348 completions to allowable structure or union fields, where appropriate.
3349 For instance, consider:
3351 # struct example { int f1; double f2; };
3352 # struct example variable;
3355 If the user types TAB at the end of this command line, the available
3356 completions will be "f1" and "f2".
3358 * Inlined functions are now supported. They show up in backtraces, and
3359 the "step", "next", and "finish" commands handle them automatically.
3361 * GDB now supports the token-splicing (##) and stringification (#)
3362 operators when expanding macros. It also supports variable-arity
3365 * GDB now supports inspecting extra signal information, exported by
3366 the new $_siginfo convenience variable. The feature is currently
3367 implemented on linux ARM, i386 and amd64.
3369 * GDB can now display the VFP floating point registers and NEON vector
3370 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3371 can provide these registers (requires Linux 2.6.30 or later). Remote
3372 and simulator targets may also provide them.
3374 * New remote packets
3377 Search memory for a sequence of bytes.
3380 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3381 operation over reliable transport links. Use of this packet is
3382 controlled by the `set remote noack-packet' command.
3385 Kill the process with the specified process ID. Use this in preference
3386 to `k' when multiprocess protocol extensions are supported.
3389 Obtains additional operating system information
3393 Read or write additional signal information.
3395 * Removed remote protocol undocumented extension
3397 An undocumented extension to the remote protocol's `S' stop reply
3398 packet that permited the stub to pass a process id was removed.
3399 Remote servers should use the `T' stop reply packet instead.
3401 * GDB now supports multiple function calling conventions according to the
3402 DWARF-2 DW_AT_calling_convention function attribute.
3404 * The SH target utilizes the aforementioned change to distinguish between gcc
3405 and Renesas calling convention. It also adds the new CLI commands
3406 `set/show sh calling-convention'.
3408 * GDB can now read compressed debug sections, as produced by GNU gold
3409 with the --compress-debug-sections=zlib flag.
3411 * 64-bit core files are now supported on AIX.
3413 * Thread switching is now supported on Tru64.
3415 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3416 which will be allocated using malloc later in program execution.
3418 * The qXfer:libraries:read remote procotol packet now allows passing a
3419 list of section offsets.
3421 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3422 conditions handling signals delivered during attach or thread creation
3423 have also been fixed.
3425 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3426 From the user's standpoint, all unqualified instances of True and False
3427 are treated as the standard definitions, regardless of context.
3429 * GDB now parses C++ symbol and type names more flexibly. For
3432 template<typename T> class C { };
3435 GDB will now correctly handle all of:
3437 ptype C<char const *>
3438 ptype C<char const*>
3439 ptype C<const char *>
3440 ptype C<const char*>
3442 * New features in the GDB remote stub, gdbserver
3444 - The "--wrapper" command-line argument tells gdbserver to use a
3445 wrapper program to launch programs for debugging.
3447 - On PowerPC and S/390 targets, it is now possible to use a single
3448 gdbserver executable to debug both 32-bit and 64-bit programs.
3449 (This requires gdbserver itself to be built as a 64-bit executable.)
3451 - gdbserver uses the new noack protocol mode for TCP connections to
3452 reduce communications latency, if also supported and enabled in GDB.
3454 - Support for the sparc64-linux-gnu target is now included in
3457 - The amd64-linux build of gdbserver now supports debugging both
3458 32-bit and 64-bit programs.
3460 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3461 now support hardware watchpoints, and will use them automatically
3466 GDB now has support for scripting using Python. Whether this is
3467 available is determined at configure time.
3469 New GDB commands can now be written in Python.
3471 * Ada tasking support
3473 Ada tasks can now be inspected in GDB. The following commands have
3477 Print the list of Ada tasks.
3479 Print detailed information about task number N.
3481 Print the task number of the current task.
3483 Switch the context of debugging to task number N.
3485 * Support for user-defined prefixed commands. The "define" command can
3486 add new commands to existing prefixes, e.g. "target".
3488 * Multi-inferior, multi-process debugging.
3490 GDB now has generalized support for multi-inferior debugging. See
3491 "Debugging Multiple Inferiors" in the manual for more information.
3492 Although availability still depends on target support, the command
3493 set is more uniform now. The GNU/Linux specific multi-forks support
3494 has been migrated to this new framework. This implied some user
3495 visible changes; see "New commands" and also "Removed commands"
3498 * Target descriptions can now describe the target OS ABI. See the
3499 "Target Description Format" section in the user manual for more
3502 * Target descriptions can now describe "compatible" architectures
3503 to indicate that the target can execute applications for a different
3504 architecture in addition to those for the main target architecture.
3505 See the "Target Description Format" section in the user manual for
3508 * Multi-architecture debugging.
3510 GDB now includes general supports for debugging applications on
3511 hybrid systems that use more than one single processor architecture
3512 at the same time. Each such hybrid architecture still requires
3513 specific support to be added. The only hybrid architecture supported
3514 in this version of GDB is the Cell Broadband Engine.
3516 * GDB now supports integrated debugging of Cell/B.E. applications that
3517 use both the PPU and SPU architectures. To enable support for hybrid
3518 Cell/B.E. debugging, you need to configure GDB to support both the
3519 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3520 --enable-targets configure option.
3522 * Non-stop mode debugging.
3524 For some targets, GDB now supports an optional mode of operation in
3525 which you can examine stopped threads while other threads continue
3526 to execute freely. This is referred to as non-stop mode, with the
3527 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3528 section in the user manual for more information.
3530 To be able to support remote non-stop debugging, a remote stub needs
3531 to implement the non-stop mode remote protocol extensions, as
3532 described in the "Remote Non-Stop" section of the user manual. The
3533 GDB remote stub, gdbserver, has been adjusted to support these
3534 extensions on linux targets.
3536 * New commands (for set/show, see "New options" below)
3538 catch syscall [NAME(S) | NUMBER(S)]
3539 Catch system calls. Arguments, which should be names of system
3540 calls or their numbers, mean catch only those syscalls. Without
3541 arguments, every syscall will be caught. When the inferior issues
3542 any of the specified syscalls, GDB will stop and announce the system
3543 call, both when it is called and when its call returns. This
3544 feature is currently available with a native GDB running on the
3545 Linux Kernel, under the following architectures: x86, x86_64,
3546 PowerPC and PowerPC64.
3548 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3550 Search memory for a sequence of bytes.
3552 maint set python print-stack
3553 maint show python print-stack
3554 Show a stack trace when an error is encountered in a Python script.
3557 Invoke CODE by passing it to the Python interpreter.
3562 These allow macros to be defined, undefined, and listed
3566 Show operating system information about processes.
3569 List the inferiors currently under GDB's control.
3572 Switch focus to inferior number NUM.
3575 Detach from inferior number NUM.
3578 Kill inferior number NUM.
3582 set spu stop-on-load
3583 show spu stop-on-load
3584 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3586 set spu auto-flush-cache
3587 show spu auto-flush-cache
3588 Control whether to automatically flush the software-managed cache
3589 during Cell/B.E. debugging.
3591 set sh calling-convention
3592 show sh calling-convention
3593 Control the calling convention used when calling SH target functions.
3596 show debug timestamp
3597 Control display of timestamps with GDB debugging output.
3599 set disassemble-next-line
3600 show disassemble-next-line
3601 Control display of disassembled source lines or instructions when
3604 set remote noack-packet
3605 show remote noack-packet
3606 Set/show the use of remote protocol QStartNoAckMode packet. See above
3607 under "New remote packets."
3609 set remote query-attached-packet
3610 show remote query-attached-packet
3611 Control use of remote protocol `qAttached' (query-attached) packet.
3613 set remote read-siginfo-object
3614 show remote read-siginfo-object
3615 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3618 set remote write-siginfo-object
3619 show remote write-siginfo-object
3620 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3623 set remote reverse-continue
3624 show remote reverse-continue
3625 Control use of remote protocol 'bc' (reverse-continue) packet.
3627 set remote reverse-step
3628 show remote reverse-step
3629 Control use of remote protocol 'bs' (reverse-step) packet.
3631 set displaced-stepping
3632 show displaced-stepping
3633 Control displaced stepping mode. Displaced stepping is a way to
3634 single-step over breakpoints without removing them from the debuggee.
3635 Also known as "out-of-line single-stepping".
3638 show debug displaced
3639 Control display of debugging info for displaced stepping.
3641 maint set internal-error
3642 maint show internal-error
3643 Control what GDB does when an internal error is detected.
3645 maint set internal-warning
3646 maint show internal-warning
3647 Control what GDB does when an internal warning is detected.
3652 Use a wrapper program to launch programs for debugging.
3654 set multiple-symbols (all|ask|cancel)
3655 show multiple-symbols
3656 The value of this variable can be changed to adjust the debugger behavior
3657 when an expression or a breakpoint location contains an ambiguous symbol
3658 name (an overloaded function name, for instance).
3660 set breakpoint always-inserted
3661 show breakpoint always-inserted
3662 Keep breakpoints always inserted in the target, as opposed to inserting
3663 them when resuming the target, and removing them when the target stops.
3664 This option can improve debugger performance on slow remote targets.
3666 set arm fallback-mode (arm|thumb|auto)
3667 show arm fallback-mode
3668 set arm force-mode (arm|thumb|auto)
3670 These commands control how ARM GDB determines whether instructions
3671 are ARM or Thumb. The default for both settings is auto, which uses
3672 the current CPSR value for instructions without symbols; previous
3673 versions of GDB behaved as if "set arm fallback-mode arm".
3675 set disable-randomization
3676 show disable-randomization
3677 Standalone programs run with the virtual address space randomization enabled
3678 by default on some platforms. This option keeps the addresses stable across
3679 multiple debugging sessions.
3683 Control whether other threads are stopped or not when some thread hits
3688 Requests that asynchronous execution is enabled in the target, if available.
3689 In this case, it's possible to resume target in the background, and interact
3690 with GDB while the target is running. "show target-async" displays the
3691 current state of asynchronous execution of the target.
3693 set target-wide-charset
3694 show target-wide-charset
3695 The target-wide-charset is the name of the character set that GDB
3696 uses when printing characters whose type is wchar_t.
3698 set tcp auto-retry (on|off)
3700 set tcp connect-timeout
3701 show tcp connect-timeout
3702 These commands allow GDB to retry failed TCP connections to a remote stub
3703 with a specified timeout period; this is useful if the stub is launched
3704 in parallel with GDB but may not be ready to accept connections immediately.
3706 set libthread-db-search-path
3707 show libthread-db-search-path
3708 Control list of directories which GDB will search for appropriate
3711 set schedule-multiple (on|off)
3712 show schedule-multiple
3713 Allow GDB to resume all threads of all processes or only threads of
3714 the current process.
3718 Use more aggressive caching for accesses to the stack. This improves
3719 performance of remote debugging (particularly backtraces) without
3720 affecting correctness.
3722 set interactive-mode (on|off|auto)
3723 show interactive-mode
3724 Control whether GDB runs in interactive mode (on) or not (off).
3725 When in interactive mode, GDB waits for the user to answer all
3726 queries. Otherwise, GDB does not wait and assumes the default
3727 answer. When set to auto (the default), GDB determines which
3728 mode to use based on the stdin settings.
3733 For program forks, this is replaced by the new more generic `info
3734 inferiors' command. To list checkpoints, you can still use the
3735 `info checkpoints' command, which was an alias for the `info forks'
3739 Replaced by the new `inferior' command. To switch between
3740 checkpoints, you can still use the `restart' command, which was an
3741 alias for the `fork' command.
3744 This is removed, since some targets don't have a notion of
3745 processes. To switch between processes, you can still use the
3746 `inferior' command using GDB's own inferior number.
3749 For program forks, this is replaced by the new more generic `kill
3750 inferior' command. To delete a checkpoint, you can still use the
3751 `delete checkpoint' command, which was an alias for the `delete
3755 For program forks, this is replaced by the new more generic `detach
3756 inferior' command. To detach a checkpoint, you can still use the
3757 `detach checkpoint' command, which was an alias for the `detach
3760 * New native configurations
3762 x86/x86_64 Darwin i[34567]86-*-darwin*
3764 x86_64 MinGW x86_64-*-mingw*
3768 Lattice Mico32 lm32-*
3769 x86 DICOS i[34567]86-*-dicos*
3770 x86_64 DICOS x86_64-*-dicos*
3773 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3774 (mingw32ce) debugging.
3780 These commands were actually not implemented on any target.
3782 *** Changes in GDB 6.8
3784 * New native configurations
3786 NetBSD/hppa hppa*-*netbsd*
3787 Xtensa GNU/Linux xtensa*-*-linux*
3791 NetBSD/hppa hppa*-*-netbsd*
3792 Xtensa GNU/Lunux xtensa*-*-linux*
3794 * Change in command line behavior -- corefiles vs. process ids.
3796 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3797 attaching to process NUMBER fails, GDB no longer attempts to open a
3798 core file named NUMBER. Attaching to a program using the -c option
3799 is no longer supported. Instead, use the '-p' or '--pid' options.
3801 * GDB can now be built as a native debugger for debugging Windows x86
3802 (mingw32) Portable Executable (PE) programs.
3804 * Pending breakpoints no longer change their number when their address
3807 * GDB now supports breakpoints with multiple locations,
3808 including breakpoints on C++ constructors, inside C++ templates,
3809 and in inlined functions.
3811 * GDB's ability to debug optimized code has been improved. GDB more
3812 accurately identifies function bodies and lexical blocks that occupy
3813 more than one contiguous range of addresses.
3815 * Target descriptions can now describe registers for PowerPC.
3817 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3818 registers on PowerPC targets.
3820 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3821 targets even when the libthread_db library is not available.
3823 * The GDB remote stub, gdbserver, now supports the new file transfer
3824 commands (remote put, remote get, and remote delete).
3826 * The GDB remote stub, gdbserver, now supports run and attach in
3827 extended-remote mode.
3829 * hppa*64*-*-hpux11* target broken
3830 The debugger is unable to start a program and fails with the following
3831 error: "Error trying to get information about dynamic linker".
3832 The gdb-6.7 release is also affected.
3834 * GDB now supports the --enable-targets= configure option to allow
3835 building a single GDB executable that supports multiple remote
3836 target architectures.
3838 * GDB now supports debugging C and C++ programs which use the
3839 Decimal Floating Point extension. In addition, the PowerPC target
3840 now has a set of pseudo-registers to inspect decimal float values
3841 stored in two consecutive float registers.
3843 * The -break-insert MI command can optionally create pending
3846 * Improved support for debugging Ada
3847 Many improvements to the Ada language support have been made. These
3849 - Better support for Ada2005 interface types
3850 - Improved handling of arrays and slices in general
3851 - Better support for Taft-amendment types
3852 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3854 - Improved command completion in Ada
3857 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3862 set print frame-arguments (all|scalars|none)
3863 show print frame-arguments
3864 The value of this variable can be changed to control which argument
3865 values should be printed by the debugger when displaying a frame.
3870 Transfer files to and from a remote target, and delete remote files.
3877 Transfer files to and from a remote target, and delete remote files.
3879 * New remote packets
3886 Open, close, read, write, and delete files on the remote system.
3889 Attach to an existing process on the remote system, in extended-remote
3893 Run a new process on the remote system, in extended-remote mode.
3895 *** Changes in GDB 6.7
3897 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3898 bfd, libiberty and opcodes, as revealed by static analysis donated by
3899 Coverity, Inc. (http://scan.coverity.com).
3901 * When looking up multiply-defined global symbols, GDB will now prefer the
3902 symbol definition in the current shared library if it was built using the
3903 -Bsymbolic linker option.
3905 * When the Text User Interface (TUI) is not configured, GDB will now
3906 recognize the -tui command-line option and print a message that the TUI
3909 * The GDB remote stub, gdbserver, now has lower overhead for high
3910 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3912 * GDB for MIPS targets now autodetects whether a remote target provides
3913 32-bit or 64-bit register values.
3915 * Support for C++ member pointers has been improved.
3917 * GDB now understands XML target descriptions, which specify the
3918 target's overall architecture. GDB can read a description from
3919 a local file or over the remote serial protocol.
3921 * Vectors of single-byte data use a new integer type which is not
3922 automatically displayed as character or string data.
3924 * The /s format now works with the print command. It displays
3925 arrays of single-byte integers and pointers to single-byte integers
3928 * Target descriptions can now describe target-specific registers,
3929 for architectures which have implemented the support (currently
3930 only ARM, M68K, and MIPS).
3932 * GDB and the GDB remote stub, gdbserver, now support the XScale
3935 * The GDB remote stub, gdbserver, has been updated to support
3936 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3937 has been rewritten to use the standard GDB remote protocol.
3939 * GDB can now step into C++ functions which are called through thunks.
3941 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3943 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3944 layout. It also supports a TextSeg= and DataSeg= response when only
3945 segment base addresses (rather than offsets) are available.
3947 * The /i format now outputs any trailing branch delay slot instructions
3948 immediately following the last instruction within the count specified.
3950 * The GDB remote protocol "T" stop reply packet now supports a
3951 "library" response. Combined with the new "qXfer:libraries:read"
3952 packet, this response allows GDB to debug shared libraries on targets
3953 where the operating system manages the list of loaded libraries (e.g.
3954 Windows and SymbianOS).
3956 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3957 (DLLs) on Windows and Windows CE targets.
3959 * GDB now supports a faster verification that a .debug file matches its binary
3960 according to its build-id signature, if the signature is present.
3966 Enable or disable hardware flow control (RTS/CTS) on the serial port
3967 when debugging using remote targets.
3969 set mem inaccessible-by-default
3970 show mem inaccessible-by-default
3971 If the target supplies a memory map, for instance via the remote
3972 protocol's "qXfer:memory-map:read" packet, setting this variable
3973 prevents GDB from accessing memory outside the memory map. This
3974 is useful for targets with memory mapped registers or which react
3975 badly to accesses of unmapped address space.
3977 set breakpoint auto-hw
3978 show breakpoint auto-hw
3979 If the target supplies a memory map, for instance via the remote
3980 protocol's "qXfer:memory-map:read" packet, setting this variable
3981 lets GDB use hardware breakpoints automatically for memory regions
3982 where it can not use software breakpoints. This covers both the
3983 "break" command and internal breakpoints used for other commands
3984 including "next" and "finish".
3987 catch exception unhandled
3988 Stop the program execution when Ada exceptions are raised.
3991 Stop the program execution when an Ada assertion failed.
3995 Set an alternate system root for target files. This is a more
3996 general version of "set solib-absolute-prefix", which is now
3997 an alias to "set sysroot".
4000 Provide extended SPU facility status information. This set of
4001 commands is available only when debugging the Cell/B.E. SPU
4004 * New native configurations
4006 OpenBSD/sh sh*-*openbsd*
4009 unset tdesc filename
4011 Use the specified local file as an XML target description, and do
4012 not query the target for its built-in description.
4016 OpenBSD/sh sh*-*-openbsd*
4017 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4018 Toshiba Media Processor mep-elf
4020 * New remote packets
4023 Ignore the specified signals; pass them directly to the debugged program
4024 without stopping other threads or reporting them to GDB.
4026 qXfer:features:read:
4027 Read an XML target description from the target, which describes its
4032 Read or write contents of an spufs file on the target system. These
4033 packets are available only on the Cell/B.E. SPU architecture.
4035 qXfer:libraries:read:
4036 Report the loaded shared libraries. Combined with new "T" packet
4037 response, this packet allows GDB to debug shared libraries on
4038 targets where the operating system manages the list of loaded
4039 libraries (e.g. Windows and SymbianOS).
4043 Support for these obsolete configurations has been removed.
4051 i[34567]86-*-lynxos*
4052 i[34567]86-*-netware*
4053 i[34567]86-*-sco3.2v5*
4054 i[34567]86-*-sco3.2v4*
4056 i[34567]86-*-sysv4.2*
4059 i[34567]86-*-unixware2*
4060 i[34567]86-*-unixware*
4069 * Other removed features
4076 Various m68k-only ROM monitors.
4083 Various Renesas ROM monitors and debugging interfaces for SH and
4088 Support for a Macraigor serial interface to on-chip debugging.
4089 GDB does not directly support the newer parallel or USB
4094 A debug information format. The predecessor to DWARF 2 and
4095 DWARF 3, which are still supported.
4097 Support for the HP aCC compiler on HP-UX/PA-RISC
4099 SOM-encapsulated symbolic debugging information, automatic
4100 invocation of pxdb, and the aCC custom C++ ABI. This does not
4101 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4102 with aCC can still be debugged on an assembly level.
4104 MIPS ".pdr" sections
4106 A MIPS-specific format used to describe stack frame layout
4107 in debugging information.
4111 GDB could work with an older version of Guile to debug
4112 the interpreter and Scheme programs running in it.
4114 set mips stack-arg-size
4115 set mips saved-gpreg-size
4117 Use "set mips abi" to control parameter passing for MIPS.
4119 *** Changes in GDB 6.6
4124 Cell Broadband Engine SPU spu-elf
4126 * GDB can now be configured as a cross-debugger targeting native Windows
4127 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4128 running on a Windows system over TCP/IP to debug Windows programs.
4130 * The GDB remote stub, gdbserver, has been updated to support Windows and
4131 Cygwin debugging. Both single-threaded and multi-threaded programs are
4134 * The "set trust-readonly-sections" command works again. This command was
4135 broken in GDB 6.3, 6.4, and 6.5.
4137 * The "load" command now supports writing to flash memory, if the remote
4138 stub provides the required support.
4140 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4141 longer requires symbolic debug information (e.g. DWARF-2).
4146 unset substitute-path
4147 show substitute-path
4148 Manage a list of substitution rules that GDB uses to rewrite the name
4149 of the directories where the sources are located. This can be useful
4150 for instance when the sources were moved to a different location
4151 between compilation and debugging.
4155 Print each CLI command as it is executed. Each command is prefixed with
4156 a number of `+' symbols representing the nesting depth.
4157 The source command now has a `-v' option to enable the same feature.
4161 The ARM Demon monitor support (RDP protocol, "target rdp").
4163 Kernel Object Display, an embedded debugging feature which only worked with
4164 an obsolete version of Cisco IOS.
4166 The 'set download-write-size' and 'show download-write-size' commands.
4168 * New remote packets
4171 Tell a stub about GDB client features, and request remote target features.
4172 The first feature implemented is PacketSize, which allows the target to
4173 specify the size of packets it can handle - to minimize the number of
4174 packets required and improve performance when connected to a remote
4178 Fetch an OS auxilliary vector from the remote stub. This packet is a
4179 more efficient replacement for qPart:auxv:read.
4181 qXfer:memory-map:read:
4182 Fetch a memory map from the remote stub, including information about
4183 RAM, ROM, and flash memory devices.
4188 Erase and program a flash memory device.
4190 * Removed remote packets
4193 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4194 used it, and only gdbserver implemented it.
4196 *** Changes in GDB 6.5
4200 Renesas M32C/M16C m32c-elf
4202 Morpho Technologies ms1 ms1-elf
4206 init-if-undefined Initialize a convenience variable, but
4207 only if it doesn't already have a value.
4209 The following commands are presently only implemented for native GNU/Linux:
4211 checkpoint Save a snapshot of the program state.
4213 restart <n> Return the program state to a
4214 previously saved state.
4216 info checkpoints List currently saved checkpoints.
4218 delete-checkpoint <n> Delete a previously saved checkpoint.
4220 set|show detach-on-fork Tell gdb whether to detach from a newly
4221 forked process, or to keep debugging it.
4223 info forks List forks of the user program that
4224 are available to be debugged.
4226 fork <n> Switch to debugging one of several
4227 forks of the user program that are
4228 available to be debugged.
4230 delete-fork <n> Delete a fork from the list of forks
4231 that are available to be debugged (and
4232 kill the forked process).
4234 detach-fork <n> Delete a fork from the list of forks
4235 that are available to be debugged (and
4236 allow the process to continue).
4240 Morpho Technologies ms2 ms1-elf
4242 * Improved Windows host support
4244 GDB now builds as a cross debugger hosted on i686-mingw32, including
4245 native console support, and remote communications using either
4246 network sockets or serial ports.
4248 * Improved Modula-2 language support
4250 GDB can now print most types in the Modula-2 syntax. This includes:
4251 basic types, set types, record types, enumerated types, range types,
4252 pointer types and ARRAY types. Procedure var parameters are correctly
4253 printed and hexadecimal addresses and character constants are also
4254 written in the Modula-2 syntax. Best results can be obtained by using
4255 GNU Modula-2 together with the -gdwarf-2 command line option.
4259 The ARM rdi-share module.
4261 The Netware NLM debug server.
4263 *** Changes in GDB 6.4
4265 * New native configurations
4267 OpenBSD/arm arm*-*-openbsd*
4268 OpenBSD/mips64 mips64-*-openbsd*
4272 Morpho Technologies ms1 ms1-elf
4274 * New command line options
4276 --batch-silent As for --batch, but totally silent.
4277 --return-child-result The debugger will exist with the same value
4278 the child (debugged) program exited with.
4279 --eval-command COMMAND, -ex COMMAND
4280 Execute a single GDB CLI command. This may be
4281 specified multiple times and in conjunction
4282 with the --command (-x) option.
4284 * Deprecated commands removed
4286 The following commands, that were deprecated in 2000, have been
4290 set|show arm disassembly-flavor set|show arm disassembler
4291 othernames set arm disassembler
4292 set|show remotedebug set|show debug remote
4293 set|show archdebug set|show debug arch
4294 set|show eventdebug set|show debug event
4297 * New BSD user-level threads support
4299 It is now possible to debug programs using the user-level threads
4300 library on OpenBSD and FreeBSD. Currently supported (target)
4303 FreeBSD/amd64 x86_64-*-freebsd*
4304 FreeBSD/i386 i386-*-freebsd*
4305 OpenBSD/i386 i386-*-openbsd*
4307 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4308 are not yet supported.
4310 * New support for Matsushita MN10300 w/sim added
4311 (Work in progress). mn10300-elf.
4313 * REMOVED configurations and files
4315 VxWorks and the XDR protocol *-*-vxworks
4316 Motorola MCORE mcore-*-*
4317 National Semiconductor NS32000 ns32k-*-*
4319 * New "set print array-indexes" command
4321 After turning this setting "on", GDB prints the index of each element
4322 when displaying arrays. The default is "off" to preserve the previous
4325 * VAX floating point support
4327 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4329 * User-defined command support
4331 In addition to using $arg0..$arg9 for argument passing, it is now possible
4332 to use $argc to determine now many arguments have been passed. See the
4333 section on user-defined commands in the user manual for more information.
4335 *** Changes in GDB 6.3:
4337 * New command line option
4339 GDB now accepts -l followed by a number to set the timeout for remote
4342 * GDB works with GCC -feliminate-dwarf2-dups
4344 GDB now supports a more compact representation of DWARF-2 debug
4345 information using DW_FORM_ref_addr references. These are produced
4346 by GCC with the option -feliminate-dwarf2-dups and also by some
4347 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4348 to use -feliminate-dwarf2-dups.
4350 * Internationalization
4352 When supported by the host system, GDB will be built with
4353 internationalization (libintl). The task of marking up the sources is
4354 continued, we're looking forward to our first translation.
4358 Initial support for debugging programs compiled with the GNAT
4359 implementation of the Ada programming language has been integrated
4360 into GDB. In this release, support is limited to expression evaluation.
4362 * New native configurations
4364 GNU/Linux/m32r m32r-*-linux-gnu
4368 GDB's remote protocol now includes support for the 'p' packet. This
4369 packet is used to fetch individual registers from a remote inferior.
4371 * END-OF-LIFE registers[] compatibility module
4373 GDB's internal register infrastructure has been completely rewritten.
4374 The new infrastructure making possible the implementation of key new
4375 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4378 GDB 6.3 will be the last release to include the the registers[]
4379 compatibility module that allowed out-of-date configurations to
4380 continue to work. This change directly impacts the following
4390 powerpc bdm protocol
4392 Unless there is activity to revive these configurations, they will be
4393 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4395 * OBSOLETE configurations and files
4397 Configurations that have been declared obsolete in this release have
4398 been commented out. Unless there is activity to revive these
4399 configurations, the next release of GDB will have their sources
4400 permanently REMOVED.
4409 *** Changes in GDB 6.2.1:
4411 * MIPS `break main; run' gave an heuristic-fence-post warning
4413 When attempting to run even a simple program, a warning about
4414 heuristic-fence-post being hit would be reported. This problem has
4417 * MIPS IRIX 'long double' crashed GDB
4419 When examining a long double variable, GDB would get a segmentation
4420 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4421 IRIX long double values).
4425 A bug in the VAX stack code was causing problems with the "next"
4426 command. This problem has been fixed.
4428 *** Changes in GDB 6.2:
4430 * Fix for ``many threads''
4432 On GNU/Linux systems that use the NPTL threads library, a program
4433 rapidly creating and deleting threads would confuse GDB leading to the
4436 ptrace: No such process.
4437 thread_db_get_info: cannot get thread info: generic error
4439 This problem has been fixed.
4441 * "-async" and "-noasync" options removed.
4443 Support for the broken "-noasync" option has been removed (it caused
4446 * New ``start'' command.
4448 This command runs the program until the begining of the main procedure.
4450 * New BSD Kernel Data Access Library (libkvm) interface
4452 Using ``target kvm'' it is now possible to debug kernel core dumps and
4453 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4454 platforms. Currently supported (native-only) configurations are:
4456 FreeBSD/amd64 x86_64-*-freebsd*
4457 FreeBSD/i386 i?86-*-freebsd*
4458 NetBSD/i386 i?86-*-netbsd*
4459 NetBSD/m68k m68*-*-netbsd*
4460 NetBSD/sparc sparc-*-netbsd*
4461 OpenBSD/amd64 x86_64-*-openbsd*
4462 OpenBSD/i386 i?86-*-openbsd*
4463 OpenBSD/m68k m68*-openbsd*
4464 OpenBSD/sparc sparc-*-openbsd*
4466 * Signal trampoline code overhauled
4468 Many generic problems with GDB's signal handling code have been fixed.
4469 These include: backtraces through non-contiguous stacks; recognition
4470 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4471 call; backtrace through a signal trampoline; step into and out of
4472 signal handlers; and single-stepping in the signal trampoline.
4474 Please note that kernel bugs are a limiting factor here. These
4475 features have been shown to work on an s390 GNU/Linux system that
4476 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4478 * Cygwin support for DWARF 2 added.
4480 * New native configurations
4482 GNU/Linux/hppa hppa*-*-linux*
4483 OpenBSD/hppa hppa*-*-openbsd*
4484 OpenBSD/m68k m68*-*-openbsd*
4485 OpenBSD/m88k m88*-*-openbsd*
4486 OpenBSD/powerpc powerpc-*-openbsd*
4487 NetBSD/vax vax-*-netbsd*
4488 OpenBSD/vax vax-*-openbsd*
4490 * END-OF-LIFE frame compatibility module
4492 GDB's internal frame infrastructure has been completely rewritten.
4493 The new infrastructure making it possible to support key new features
4494 including DWARF 2 Call Frame Information. To aid in the task of
4495 migrating old configurations to this new infrastructure, a
4496 compatibility module, that allowed old configurations to continue to
4497 work, was also included.
4499 GDB 6.2 will be the last release to include this frame compatibility
4500 module. This change directly impacts the following configurations:
4510 Unless there is activity to revive these configurations, they will be
4511 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4513 * REMOVED configurations and files
4515 Sun 3, running SunOS 3 m68*-*-sunos3*
4516 Sun 3, running SunOS 4 m68*-*-sunos4*
4517 Sun 2, running SunOS 3 m68000-*-sunos3*
4518 Sun 2, running SunOS 4 m68000-*-sunos4*
4519 Motorola 680x0 running LynxOS m68*-*-lynxos*
4520 AT&T 3b1/Unix pc m68*-att-*
4521 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4522 decstation mips-dec-* mips-little-*
4523 riscos mips-*-riscos* mips-*-sysv*
4524 sonymips mips-sony-*
4525 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4527 *** Changes in GDB 6.1.1:
4529 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4531 The TUI (Text-mode User Interface) is now built as part of a default
4532 GDB configuration. It is enabled by either selecting the TUI with the
4533 command line option "-i=tui" or by running the separate "gdbtui"
4534 program. For more information on the TUI, see the manual "Debugging
4537 * Pending breakpoint support (also included in GDB 6.1)
4539 Support has been added to allow you to specify breakpoints in shared
4540 libraries that have not yet been loaded. If a breakpoint location
4541 cannot be found, and the "breakpoint pending" option is set to auto,
4542 GDB queries you if you wish to make the breakpoint pending on a future
4543 shared-library load. If and when GDB resolves the breakpoint symbol,
4544 the pending breakpoint is removed as one or more regular breakpoints
4547 Pending breakpoints are very useful for GCJ Java debugging.
4549 * Fixed ISO-C build problems
4551 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4552 non ISO-C code that stopped them being built using a more strict ISO-C
4553 compiler (e.g., IBM's C compiler).
4555 * Fixed build problem on IRIX 5
4557 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4558 wasn't able to compile compile on an IRIX 5 system.
4560 * Added execute permission to gdb/gdbserver/configure
4562 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4563 permission. This bug would cause configure to fail on a number of
4564 systems (Solaris, IRIX). Ref: server/519.
4566 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4568 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4569 has been updated to use constant array sizes.
4571 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4573 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4574 its generated DWARF Call Frame Info. This encoding was causing GDB to
4575 panic, that panic has been fixed. Ref: gdb/1628.
4577 * Fixed a problem when examining parameters in shared library code.
4579 When examining parameters in optimized shared library code generated
4580 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4581 not available''. GDB now correctly displays the variable's value.
4583 *** Changes in GDB 6.1:
4585 * Removed --with-mmalloc
4587 Support for the mmalloc memory manager has been removed, as it
4588 conflicted with the internal gdb byte cache.
4590 * Changes in AMD64 configurations
4592 The AMD64 target now includes the %cs and %ss registers. As a result
4593 the AMD64 remote protocol has changed; this affects the floating-point
4594 and SSE registers. If you rely on those registers for your debugging,
4595 you should upgrade gdbserver on the remote side.
4597 * Revised SPARC target
4599 The SPARC target has been completely revised, incorporating the
4600 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4601 support for LynxOS and SunOS 4 has been dropped. Calling functions
4602 from within GDB on operating systems with a non-executable stack
4603 (Solaris, OpenBSD) now works.
4607 GDB has a new C++ demangler which does a better job on the mangled
4608 names generated by current versions of g++. It also runs faster, so
4609 with this and other changes gdb should now start faster on large C++
4612 * DWARF 2 Location Expressions
4614 GDB support for location expressions has been extended to support function
4615 arguments and frame bases. Older versions of GDB could crash when they
4618 * C++ nested types and namespaces
4620 GDB's support for nested types and namespaces in C++ has been
4621 improved, especially if you use the DWARF 2 debugging format. (This
4622 is the default for recent versions of GCC on most platforms.)
4623 Specifically, if you have a class "Inner" defined within a class or
4624 namespace "Outer", then GDB realizes that the class's name is
4625 "Outer::Inner", not simply "Inner". This should greatly reduce the
4626 frequency of complaints about not finding RTTI symbols. In addition,
4627 if you are stopped at inside of a function defined within a namespace,
4628 GDB modifies its name lookup accordingly.
4630 * New native configurations
4632 NetBSD/amd64 x86_64-*-netbsd*
4633 OpenBSD/amd64 x86_64-*-openbsd*
4634 OpenBSD/alpha alpha*-*-openbsd*
4635 OpenBSD/sparc sparc-*-openbsd*
4636 OpenBSD/sparc64 sparc64-*-openbsd*
4638 * New debugging protocols
4640 M32R with SDI protocol m32r-*-elf*
4642 * "set prompt-escape-char" command deleted.
4644 The command "set prompt-escape-char" has been deleted. This command,
4645 and its very obscure effet on GDB's prompt, was never documented,
4646 tested, nor mentioned in the NEWS file.
4648 * OBSOLETE configurations and files
4650 Configurations that have been declared obsolete in this release have
4651 been commented out. Unless there is activity to revive these
4652 configurations, the next release of GDB will have their sources
4653 permanently REMOVED.
4655 Sun 3, running SunOS 3 m68*-*-sunos3*
4656 Sun 3, running SunOS 4 m68*-*-sunos4*
4657 Sun 2, running SunOS 3 m68000-*-sunos3*
4658 Sun 2, running SunOS 4 m68000-*-sunos4*
4659 Motorola 680x0 running LynxOS m68*-*-lynxos*
4660 AT&T 3b1/Unix pc m68*-att-*
4661 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4662 decstation mips-dec-* mips-little-*
4663 riscos mips-*-riscos* mips-*-sysv*
4664 sonymips mips-sony-*
4665 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4667 * REMOVED configurations and files
4669 SGI Irix-4.x mips-sgi-irix4 or iris4
4670 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4671 Z8000 simulator z8k-zilog-none or z8ksim
4672 Matsushita MN10200 w/simulator mn10200-*-*
4673 H8/500 simulator h8500-hitachi-hms or h8500hms
4674 HP/PA running BSD hppa*-*-bsd*
4675 HP/PA running OSF/1 hppa*-*-osf*
4676 HP/PA Pro target hppa*-*-pro*
4677 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4678 386BSD i[3456]86-*-bsd*
4679 Sequent family i[3456]86-sequent-sysv4*
4680 i[3456]86-sequent-sysv*
4681 i[3456]86-sequent-bsd*
4682 SPARC running LynxOS sparc-*-lynxos*
4683 SPARC running SunOS 4 sparc-*-sunos4*
4684 Tsqware Sparclet sparclet-*-*
4685 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4687 *** Changes in GDB 6.0:
4691 Support for debugging the Objective-C programming language has been
4692 integrated into GDB.
4694 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4696 DWARF 2's Call Frame Information makes available compiler generated
4697 information that more exactly describes the program's run-time stack.
4698 By using this information, GDB is able to provide more robust stack
4701 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4702 have been updated to use a new backtrace mechanism which includes
4703 DWARF 2 CFI support.
4707 GDB's remote protocol has been extended to include support for hosted
4708 file I/O (where the remote target uses GDB's file system). See GDB's
4709 remote protocol documentation for details.
4711 * All targets using the new architecture framework.
4713 All of GDB's targets have been updated to use the new internal
4714 architecture framework. The way is now open for future GDB releases
4715 to include cross-architecture native debugging support (i386 on amd64,
4718 * GNU/Linux's Thread Local Storage (TLS)
4720 GDB now includes support for for the GNU/Linux implementation of
4721 per-thread variables.
4723 * GNU/Linux's Native POSIX Thread Library (NPTL)
4725 GDB's thread code has been updated to work with either the new
4726 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4728 * Separate debug info.
4730 GDB, in conjunction with BINUTILS, now supports a mechanism for
4731 automatically loading debug information from a separate file. Instead
4732 of shipping full debug and non-debug versions of system libraries,
4733 system integrators can now instead ship just the stripped libraries
4734 and optional debug files.
4736 * DWARF 2 Location Expressions
4738 DWARF 2 Location Expressions allow the compiler to more completely
4739 describe the location of variables (even in optimized code) to the
4742 GDB now includes preliminary support for location expressions (support
4743 for DW_OP_piece is still missing).
4747 A number of long standing bugs that caused GDB to die while starting a
4748 Java application have been fixed. GDB's Java support is now
4749 considered "useable".
4751 * GNU/Linux support for fork, vfork, and exec.
4753 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4754 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4757 * GDB supports logging output to a file
4759 There are two new commands, "set logging" and "show logging", which can be
4760 used to capture GDB's output to a file.
4762 * The meaning of "detach" has changed for gdbserver
4764 The "detach" command will now resume the application, as documented. To
4765 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4768 * d10v, m68hc11 `regs' command deprecated
4770 The `info registers' command has been updated so that it displays the
4771 registers using a format identical to the old `regs' command.
4775 A new command, "maint set profile on/off", has been added. This command can
4776 be used to enable or disable profiling while running GDB, to profile a
4777 session or a set of commands. In addition there is a new configure switch,
4778 "--enable-profiling", which will cause GDB to be compiled with profiling
4779 data, for more informative profiling results.
4781 * Default MI syntax changed to "mi2".
4783 The default MI (machine interface) syntax, enabled by the command line
4784 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4785 "mi1", can be enabled by specifying the option "-i=mi1".
4787 Support for the original "mi0" syntax (included in GDB 5.0) has been
4790 Fix for gdb/192: removed extraneous space when displaying frame level.
4791 Fix for gdb/672: update changelist is now output in mi list format.
4792 Fix for gdb/702: a -var-assign that updates the value now shows up
4793 in a subsequent -var-update.
4795 * New native configurations.
4797 FreeBSD/amd64 x86_64-*-freebsd*
4799 * Multi-arched targets.
4801 HP/PA HPUX11 hppa*-*-hpux*
4802 Renesas M32R/D w/simulator m32r-*-elf*
4804 * OBSOLETE configurations and files
4806 Configurations that have been declared obsolete in this release have
4807 been commented out. Unless there is activity to revive these
4808 configurations, the next release of GDB will have their sources
4809 permanently REMOVED.
4811 Z8000 simulator z8k-zilog-none or z8ksim
4812 Matsushita MN10200 w/simulator mn10200-*-*
4813 H8/500 simulator h8500-hitachi-hms or h8500hms
4814 HP/PA running BSD hppa*-*-bsd*
4815 HP/PA running OSF/1 hppa*-*-osf*
4816 HP/PA Pro target hppa*-*-pro*
4817 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4818 Sequent family i[3456]86-sequent-sysv4*
4819 i[3456]86-sequent-sysv*
4820 i[3456]86-sequent-bsd*
4821 Tsqware Sparclet sparclet-*-*
4822 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4824 * REMOVED configurations and files
4827 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4828 IBM AIX PS/2 i[3456]86-*-aix
4829 i386 running Mach 3.0 i[3456]86-*-mach3*
4830 i386 running Mach i[3456]86-*-mach*
4831 i386 running OSF/1 i[3456]86-*osf1mk*
4832 HP/Apollo 68k Family m68*-apollo*-sysv*,
4834 m68*-hp-bsd*, m68*-hp-hpux*
4835 Argonaut Risc Chip (ARC) arc-*-*
4836 Mitsubishi D30V d30v-*-*
4837 Fujitsu FR30 fr30-*-elf*
4838 OS/9000 i[34]86-*-os9k
4839 I960 with MON960 i960-*-coff
4841 * MIPS $fp behavior changed
4843 The convenience variable $fp, for the MIPS, now consistently returns
4844 the address of the current frame's base. Previously, depending on the
4845 context, $fp could refer to either $sp or the current frame's base
4846 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4847 The GNU Source-Level Debugger''.
4849 *** Changes in GDB 5.3:
4851 * GNU/Linux shared library multi-threaded performance improved.
4853 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4854 `/proc', in preference to `ptrace' for memory reads. This may result
4855 in an improvement in the start-up time of multi-threaded, shared
4856 library applications when run under GDB. One GDB user writes: ``loads
4857 shared libs like mad''.
4859 * ``gdbserver'' now supports multi-threaded applications on some targets
4861 Support for debugging multi-threaded applications which use
4862 the GNU/Linux LinuxThreads package has been added for
4863 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4864 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4866 * GDB now supports C/C++ preprocessor macros.
4868 GDB now expands preprocessor macro invocations in C/C++ expressions,
4869 and provides various commands for showing macro definitions and how
4872 The new command `macro expand EXPRESSION' expands any macro
4873 invocations in expression, and shows the result.
4875 The new command `show macro MACRO-NAME' shows the definition of the
4876 macro named MACRO-NAME, and where it was defined.
4878 Most compilers don't include information about macros in the debugging
4879 information by default. In GCC 3.1, for example, you need to compile
4880 your program with the options `-gdwarf-2 -g3'. If the macro
4881 information is present in the executable, GDB will read it.
4883 * Multi-arched targets.
4885 DEC Alpha (partial) alpha*-*-*
4886 DEC VAX (partial) vax-*-*
4888 National Semiconductor NS32000 (partial) ns32k-*-*
4889 Motorola 68000 (partial) m68k-*-*
4890 Motorola MCORE mcore-*-*
4894 Fujitsu FRV architecture added by Red Hat frv*-*-*
4897 * New native configurations
4899 Alpha NetBSD alpha*-*-netbsd*
4900 SH NetBSD sh*-*-netbsdelf*
4901 MIPS NetBSD mips*-*-netbsd*
4902 UltraSPARC NetBSD sparc64-*-netbsd*
4904 * OBSOLETE configurations and files
4906 Configurations that have been declared obsolete in this release have
4907 been commented out. Unless there is activity to revive these
4908 configurations, the next release of GDB will have their sources
4909 permanently REMOVED.
4911 Mitsubishi D30V d30v-*-*
4912 OS/9000 i[34]86-*-os9k
4913 IBM AIX PS/2 i[3456]86-*-aix
4914 Fujitsu FR30 fr30-*-elf*
4915 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4916 Argonaut Risc Chip (ARC) arc-*-*
4917 i386 running Mach 3.0 i[3456]86-*-mach3*
4918 i386 running Mach i[3456]86-*-mach*
4919 i386 running OSF/1 i[3456]86-*osf1mk*
4920 HP/Apollo 68k Family m68*-apollo*-sysv*,
4922 m68*-hp-bsd*, m68*-hp-hpux*
4923 I960 with MON960 i960-*-coff
4925 * OBSOLETE languages
4927 CHILL, a Pascal like language used by telecommunications companies.
4929 * REMOVED configurations and files
4931 AMD 29k family via UDI a29k-amd-udi, udi29k
4932 A29K VxWorks a29k-*-vxworks
4933 AMD 29000 embedded, using EBMON a29k-none-none
4934 AMD 29000 embedded with COFF a29k-none-coff
4935 AMD 29000 embedded with a.out a29k-none-aout
4937 testsuite/gdb.hp/gdb.threads-hp/ directory
4939 * New command "set max-user-call-depth <nnn>"
4941 This command allows the user to limit the call depth of user-defined
4942 commands. The default is 1024.
4944 * Changes in FreeBSD/i386 native debugging.
4946 Support for the "generate-core-file" has been added.
4948 * New commands "dump", "append", and "restore".
4950 These commands allow data to be copied from target memory
4951 to a bfd-format or binary file (dump and append), and back
4952 from a file into memory (restore).
4954 * Improved "next/step" support on multi-processor Alpha Tru64.
4956 The previous single-step mechanism could cause unpredictable problems,
4957 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4958 of a software single-step mechanism prevents this.
4960 *** Changes in GDB 5.2.1:
4968 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4969 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4970 Fix, by Joel Brobecker imported from mainline.
4972 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4973 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4974 Fix, by Fred Fish, imported from mainline.
4976 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4977 Surprisingly enough, it works now.
4978 By Michal Ludvig, imported from mainline.
4980 i386 hardware watchpoint support:
4981 avoid misses on second run for some targets.
4982 By Pierre Muller, imported from mainline.
4984 *** Changes in GDB 5.2:
4986 * New command "set trust-readonly-sections on[off]".
4988 This command is a hint that tells gdb that read-only sections
4989 really are read-only (ie. that their contents will not change).
4990 In this mode, gdb will go to the object file rather than the
4991 target to read memory from read-only sections (such as ".text").
4992 This can be a significant performance improvement on some
4993 (notably embedded) targets.
4995 * New command "generate-core-file" (or "gcore").
4997 This new gdb command allows the user to drop a core file of the child
4998 process state at any time. So far it's been implemented only for
4999 GNU/Linux and Solaris, but should be relatively easily ported to other
5000 hosts. Argument is core file name (defaults to core.<pid>).
5002 * New command line option
5004 GDB now accepts --pid or -p followed by a process id.
5006 * Change in command line behavior -- corefiles vs. process ids.
5008 There is a subtle behavior in the way in which GDB handles
5009 command line arguments. The first non-flag argument is always
5010 a program to debug, but the second non-flag argument may either
5011 be a corefile or a process id. Previously, GDB would attempt to
5012 open the second argument as a corefile, and if that failed, would
5013 issue a superfluous error message and then attempt to attach it as
5014 a process. Now, if the second argument begins with a non-digit,
5015 it will be treated as a corefile. If it begins with a digit,
5016 GDB will attempt to attach it as a process, and if no such process
5017 is found, will then attempt to open it as a corefile.
5019 * Changes in ARM configurations.
5021 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5022 configuration is fully multi-arch.
5024 * New native configurations
5026 ARM NetBSD arm*-*-netbsd*
5027 x86 OpenBSD i[3456]86-*-openbsd*
5028 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5029 Sparc64 running FreeBSD sparc64-*-freebsd*
5033 Sanyo XStormy16 xstormy16-elf
5035 * OBSOLETE configurations and files
5037 Configurations that have been declared obsolete in this release have
5038 been commented out. Unless there is activity to revive these
5039 configurations, the next release of GDB will have their sources
5040 permanently REMOVED.
5042 AMD 29k family via UDI a29k-amd-udi, udi29k
5043 A29K VxWorks a29k-*-vxworks
5044 AMD 29000 embedded, using EBMON a29k-none-none
5045 AMD 29000 embedded with COFF a29k-none-coff
5046 AMD 29000 embedded with a.out a29k-none-aout
5048 testsuite/gdb.hp/gdb.threads-hp/ directory
5050 * REMOVED configurations and files
5052 TI TMS320C80 tic80-*-*
5054 PowerPC Solaris powerpcle-*-solaris*
5055 PowerPC Windows NT powerpcle-*-cygwin32
5056 PowerPC Netware powerpc-*-netware*
5057 Harris/CXUX m88k m88*-harris-cxux*
5058 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5059 ns32k-utek-sysv* ns32k-utek-*
5060 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5061 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5062 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5063 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5064 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5066 * Changes to command line processing
5068 The new `--args' feature can be used to specify command-line arguments
5069 for the inferior from gdb's command line.
5071 * Changes to key bindings
5073 There is a new `operate-and-get-next' function bound to `C-o'.
5075 *** Changes in GDB 5.1.1
5077 Fix compile problem on DJGPP.
5079 Fix a problem with floating-point registers on the i386 being
5082 Fix to stop GDB crashing on .debug_str debug info.
5084 Numerous documentation fixes.
5086 Numerous testsuite fixes.
5088 *** Changes in GDB 5.1:
5090 * New native configurations
5092 Alpha FreeBSD alpha*-*-freebsd*
5093 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5094 MIPS GNU/Linux mips*-*-linux*
5095 MIPS SGI Irix 6.x mips*-sgi-irix6*
5096 ia64 AIX ia64-*-aix*
5097 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5101 Motorola 68HC11 and 68HC12 m68hc11-elf
5103 UltraSparc running GNU/Linux sparc64-*-linux*
5105 * OBSOLETE configurations and files
5107 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5108 Harris/CXUX m88k m88*-harris-cxux*
5109 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5110 ns32k-utek-sysv* ns32k-utek-*
5111 TI TMS320C80 tic80-*-*
5113 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5114 PowerPC Solaris powerpcle-*-solaris*
5115 PowerPC Windows NT powerpcle-*-cygwin32
5116 PowerPC Netware powerpc-*-netware*
5117 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5118 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5119 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5120 Apple Macintosh (MPW) host N/A
5122 stuff.c (Program to stuff files into a specially prepared space in kdb)
5123 kdb-start.c (Main loop for the standalone kernel debugger)
5125 Configurations that have been declared obsolete in this release have
5126 been commented out. Unless there is activity to revive these
5127 configurations, the next release of GDB will have their sources
5128 permanently REMOVED.
5130 * REMOVED configurations and files
5132 Altos 3068 m68*-altos-*
5133 Convex c1-*-*, c2-*-*
5135 ARM RISCix arm-*-* (as host)
5139 * GDB has been converted to ISO C.
5141 GDB's source code has been converted to ISO C. In particular, the
5142 sources are fully protoized, and rely on standard headers being
5147 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5149 * The MI enabled by default.
5151 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5152 revised and enabled by default. Packages which use GDB as a debugging
5153 engine behind a UI or another front end are encouraged to switch to
5154 using the GDB/MI interface, instead of the old annotations interface
5155 which is now deprecated.
5157 * Support for debugging Pascal programs.
5159 GDB now includes support for debugging Pascal programs. The following
5160 main features are supported:
5162 - Pascal-specific data types such as sets;
5164 - automatic recognition of Pascal sources based on file-name
5167 - Pascal-style display of data types, variables, and functions;
5169 - a Pascal expression parser.
5171 However, some important features are not yet supported.
5173 - Pascal string operations are not supported at all;
5175 - there are some problems with boolean types;
5177 - Pascal type hexadecimal constants are not supported
5178 because they conflict with the internal variables format;
5180 - support for Pascal objects and classes is not full yet;
5182 - unlike Pascal, GDB is case-sensitive for symbol names.
5184 * Changes in completion.
5186 Commands such as `shell', `run' and `set args', which pass arguments
5187 to inferior programs, now complete on file names, similar to what
5188 users expect at the shell prompt.
5190 Commands which accept locations, such as `disassemble', `print',
5191 `breakpoint', `until', etc. now complete on filenames as well as
5192 program symbols. Thus, if you type "break foob TAB", and the source
5193 files linked into the programs include `foobar.c', that file name will
5194 be one of the candidates for completion. However, file names are not
5195 considered for completion after you typed a colon that delimits a file
5196 name from a name of a function in that file, as in "break foo.c:bar".
5198 `set demangle-style' completes on available demangling styles.
5200 * New platform-independent commands:
5202 It is now possible to define a post-hook for a command as well as a
5203 hook that runs before the command. For more details, see the
5204 documentation of `hookpost' in the GDB manual.
5206 * Changes in GNU/Linux native debugging.
5208 Support for debugging multi-threaded programs has been completely
5209 revised for all platforms except m68k and sparc. You can now debug as
5210 many threads as your system allows you to have.
5212 Attach/detach is supported for multi-threaded programs.
5214 Support for SSE registers was added for x86. This doesn't work for
5215 multi-threaded programs though.
5217 * Changes in MIPS configurations.
5219 Multi-arch support is enabled for all MIPS configurations.
5221 GDB can now be built as native debugger on SGI Irix 6.x systems for
5222 debugging n32 executables. (Debugging 64-bit executables is not yet
5225 * Unified support for hardware watchpoints in all x86 configurations.
5227 Most (if not all) native x86 configurations support hardware-assisted
5228 breakpoints and watchpoints in a unified manner. This support
5229 implements debug register sharing between watchpoints, which allows to
5230 put a virtually infinite number of watchpoints on the same address,
5231 and also supports watching regions up to 16 bytes with several debug
5234 The new maintenance command `maintenance show-debug-regs' toggles
5235 debugging print-outs in functions that insert, remove, and test
5236 watchpoints and hardware breakpoints.
5238 * Changes in the DJGPP native configuration.
5240 New command ``info dos sysinfo'' displays assorted information about
5241 the CPU, OS, memory, and DPMI server.
5243 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5244 display information about segment descriptors stored in GDT, LDT, and
5247 New commands ``info dos pde'' and ``info dos pte'' display entries
5248 from Page Directory and Page Tables (for now works with CWSDPMI only).
5249 New command ``info dos address-pte'' displays the Page Table entry for
5250 a given linear address.
5252 GDB can now pass command lines longer than 126 characters to the
5253 program being debugged (requires an update to the libdbg.a library
5254 which is part of the DJGPP development kit).
5256 DWARF2 debug info is now supported.
5258 It is now possible to `step' and `next' through calls to `longjmp'.
5260 * Changes in documentation.
5262 All GDB documentation was converted to GFDL, the GNU Free
5263 Documentation License.
5265 Tracepoints-related commands are now fully documented in the GDB
5268 TUI, the Text-mode User Interface, is now documented in the manual.
5270 Tracepoints-related commands are now fully documented in the GDB
5273 The "GDB Internals" manual now has an index. It also includes
5274 documentation of `ui_out' functions, GDB coding standards, x86
5275 hardware watchpoints, and memory region attributes.
5277 * GDB's version number moved to ``version.in''
5279 The Makefile variable VERSION has been replaced by the file
5280 ``version.in''. People creating GDB distributions should update the
5281 contents of this file.
5285 GUD support is now a standard part of the EMACS distribution.
5287 *** Changes in GDB 5.0:
5289 * Improved support for debugging FP programs on x86 targets
5291 Unified and much-improved support for debugging floating-point
5292 programs on all x86 targets. In particular, ``info float'' now
5293 displays the FP registers in the same format on all x86 targets, with
5294 greater level of detail.
5296 * Improvements and bugfixes in hardware-assisted watchpoints
5298 It is now possible to watch array elements, struct members, and
5299 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5300 on x86 targets no longer erroneously trigger when the address is
5303 * Improvements in the native DJGPP version of GDB
5305 The distribution now includes all the scripts and auxiliary files
5306 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5307 machines ``out of the box''.
5309 The DJGPP version can now debug programs that use signals. It is
5310 possible to catch signals that happened in the debuggee, deliver
5311 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5312 would kill the program being debugged.) Programs that hook hardware
5313 interrupts (keyboard, timer, etc.) can also be debugged.
5315 It is now possible to debug DJGPP programs that redirect their
5316 standard handles or switch them to raw (as opposed to cooked) mode, or
5317 even close them. The command ``run < foo > bar'' works as expected,
5318 and ``info terminal'' reports useful information about the debuggee's
5319 terminal, including raw/cooked mode, redirection, etc.
5321 The DJGPP version now uses termios functions for console I/O, which
5322 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5325 DOS-style file names with drive letters are now fully supported by
5328 It is now possible to debug DJGPP programs that switch their working
5329 directory. It is also possible to rerun the debuggee any number of
5330 times without restarting GDB; thus, you can use the same setup,
5331 breakpoints, etc. for many debugging sessions.
5333 * New native configurations
5335 ARM GNU/Linux arm*-*-linux*
5336 PowerPC GNU/Linux powerpc-*-linux*
5340 Motorola MCore mcore-*-*
5341 x86 VxWorks i[3456]86-*-vxworks*
5342 PowerPC VxWorks powerpc-*-vxworks*
5343 TI TMS320C80 tic80-*-*
5345 * OBSOLETE configurations
5347 Altos 3068 m68*-altos-*
5348 Convex c1-*-*, c2-*-*
5350 ARM RISCix arm-*-* (as host)
5353 Configurations that have been declared obsolete will be commented out,
5354 but the code will be left in place. If there is no activity to revive
5355 these configurations before the next release of GDB, the sources will
5356 be permanently REMOVED.
5358 * Gould support removed
5360 Support for the Gould PowerNode and NP1 has been removed.
5362 * New features for SVR4
5364 On SVR4 native platforms (such as Solaris), if you attach to a process
5365 without first loading a symbol file, GDB will now attempt to locate and
5366 load symbols from the running process's executable file.
5368 * Many C++ enhancements
5370 C++ support has been greatly improved. Overload resolution now works properly
5371 in almost all cases. RTTI support is on the way.
5373 * Remote targets can connect to a sub-program
5375 A popen(3) style serial-device has been added. This device starts a
5376 sub-process (such as a stand-alone simulator) and then communicates
5377 with that. The sub-program to run is specified using the syntax
5378 ``|<program> <args>'' vis:
5380 (gdb) set remotedebug 1
5381 (gdb) target extended-remote |mn10300-elf-sim program-args
5383 * MIPS 64 remote protocol
5385 A long standing bug in the mips64 remote protocol where by GDB
5386 expected certain 32 bit registers (ex SR) to be transfered as 32
5387 instead of 64 bits has been fixed.
5389 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5390 added to provide backward compatibility with older versions of GDB.
5392 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5394 The command ``set remotebinarydownload'' command has been replaced by
5395 ``set remote X-packet''. Other commands in ``set remote'' family
5396 include ``set remote P-packet''.
5398 * Breakpoint commands accept ranges.
5400 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5401 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5402 ``tracepoint passcount'' also accepts a range of tracepoints.
5404 * ``apropos'' command added.
5406 The ``apropos'' command searches through command names and
5407 documentation strings, printing out matches, making it much easier to
5408 try to find a command that does what you are looking for.
5412 A new machine oriented interface (MI) has been added to GDB. This
5413 interface is designed for debug environments running GDB as a separate
5414 process. This is part of the long term libGDB project. See the
5415 "GDB/MI" chapter of the GDB manual for further information. It can be
5416 enabled by configuring with:
5418 .../configure --enable-gdbmi
5420 *** Changes in GDB-4.18:
5422 * New native configurations
5424 HP-UX 10.20 hppa*-*-hpux10.20
5425 HP-UX 11.x hppa*-*-hpux11.0*
5426 M68K GNU/Linux m68*-*-linux*
5430 Fujitsu FR30 fr30-*-elf*
5431 Intel StrongARM strongarm-*-*
5432 Mitsubishi D30V d30v-*-*
5434 * OBSOLETE configurations
5436 Gould PowerNode, NP1 np1-*-*, pn-*-*
5438 Configurations that have been declared obsolete will be commented out,
5439 but the code will be left in place. If there is no activity to revive
5440 these configurations before the next release of GDB, the sources will
5441 be permanently REMOVED.
5445 As a compatibility experiment, GDB's source files buildsym.h and
5446 buildsym.c have been converted to pure standard C, no longer
5447 containing any K&R compatibility code. We believe that all systems in
5448 use today either come with a standard C compiler, or have a GCC port
5449 available. If this is not true, please report the affected
5450 configuration to bug-gdb@gnu.org immediately. See the README file for
5451 information about getting a standard C compiler if you don't have one
5456 GDB now uses readline 2.2.
5458 * set extension-language
5460 You can now control the mapping between filename extensions and source
5461 languages by using the `set extension-language' command. For instance,
5462 you can ask GDB to treat .c files as C++ by saying
5463 set extension-language .c c++
5464 The command `info extensions' lists all of the recognized extensions
5465 and their associated languages.
5467 * Setting processor type for PowerPC and RS/6000
5469 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5470 you can use the `set processor' command to specify what variant of the
5471 PowerPC family you are debugging. The command
5475 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5476 following PowerPC and RS6000 variants:
5478 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5479 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5481 403GC IBM PowerPC 403GC
5482 505 Motorola PowerPC 505
5483 860 Motorola PowerPC 860 or 850
5484 601 Motorola PowerPC 601
5485 602 Motorola PowerPC 602
5486 603 Motorola/IBM PowerPC 603 or 603e
5487 604 Motorola PowerPC 604 or 604e
5488 750 Motorola/IBM PowerPC 750 or 750
5490 At the moment, this command just tells GDB what to name the
5491 special-purpose processor registers. Since almost all the affected
5492 registers are inaccessible to user-level programs, this command is
5493 only useful for remote debugging in its present form.
5497 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5498 more extensive support for HP-UX. Added features include shared
5499 library support, kernel threads and hardware watchpoints for 11.00,
5500 support for HP's ANSI C and C++ compilers, and a compatibility mode
5501 for xdb and dbx commands.
5505 HP's donation includes the new concept of catchpoints, which is a
5506 generalization of the old catch command. On HP-UX, it is now possible
5507 to catch exec, fork, and vfork, as well as library loading.
5509 This means that the existing catch command has changed; its first
5510 argument now specifies the type of catch to be set up. See the
5511 output of "help catch" for a list of catchpoint types.
5513 * Debugging across forks
5515 On HP-UX, you can choose which process to debug when a fork() happens
5520 HP has donated a curses-based terminal user interface (TUI). To get
5521 it, build with --enable-tui. Although this can be enabled for any
5522 configuration, at present it only works for native HP debugging.
5524 * GDB remote protocol additions
5526 A new protocol packet 'X' that writes binary data is now available.
5527 Default behavior is to try 'X', then drop back to 'M' if the stub
5528 fails to respond. The settable variable `remotebinarydownload'
5529 allows explicit control over the use of 'X'.
5531 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5532 full 64-bit address. The command
5534 set remoteaddresssize 32
5536 can be used to revert to the old behaviour. For existing remote stubs
5537 the change should not be noticed, as the additional address information
5540 In order to assist in debugging stubs, you may use the maintenance
5541 command `packet' to send any text string to the stub. For instance,
5543 maint packet heythere
5545 sends the packet "$heythere#<checksum>". Note that it is very easy to
5546 disrupt a debugging session by sending the wrong packet at the wrong
5549 The compare-sections command allows you to compare section data on the
5550 target to what is in the executable file without uploading or
5551 downloading, by comparing CRC checksums.
5553 * Tracing can collect general expressions
5555 You may now collect general expressions at tracepoints. This requires
5556 further additions to the target-side stub; see tracepoint.c and
5557 doc/agentexpr.texi for further details.
5559 * mask-address variable for Mips
5561 For Mips targets, you may control the zeroing of the upper 32 bits of
5562 a 64-bit address by entering `set mask-address on'. This is mainly
5563 of interest to users of embedded R4xxx and R5xxx processors.
5565 * Higher serial baud rates
5567 GDB's serial code now allows you to specify baud rates 57600, 115200,
5568 230400, and 460800 baud. (Note that your host system may not be able
5569 to achieve all of these rates.)
5573 The i960 configuration now includes an initial implementation of a
5574 builtin simulator, contributed by Jim Wilson.
5577 *** Changes in GDB-4.17:
5579 * New native configurations
5581 Alpha GNU/Linux alpha*-*-linux*
5582 Unixware 2.x i[3456]86-unixware2*
5583 Irix 6.x mips*-sgi-irix6*
5584 PowerPC GNU/Linux powerpc-*-linux*
5585 PowerPC Solaris powerpcle-*-solaris*
5586 Sparc GNU/Linux sparc-*-linux*
5587 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5591 Argonaut Risc Chip (ARC) arc-*-*
5592 Hitachi H8/300S h8300*-*-*
5593 Matsushita MN10200 w/simulator mn10200-*-*
5594 Matsushita MN10300 w/simulator mn10300-*-*
5595 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5596 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5597 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5598 Mitsubishi D10V w/simulator d10v-*-*
5599 Mitsubishi M32R/D w/simulator m32r-*-elf*
5600 Tsqware Sparclet sparclet-*-*
5601 NEC V850 w/simulator v850-*-*
5603 * New debugging protocols
5605 ARM with RDI protocol arm*-*-*
5606 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5607 DDB and LSI variants of PMON protocol mips*-*-*
5608 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5609 PowerPC with SDS protocol powerpc{,le}-*-eabi
5610 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5614 All configurations can now understand and use the DWARF 2 debugging
5615 format. The choice is automatic, if the symbol file contains DWARF 2
5620 GDB now includes basic Java language support. This support is
5621 only useful with Java compilers that produce native machine code.
5623 * solib-absolute-prefix and solib-search-path
5625 For SunOS and SVR4 shared libraries, you may now set the prefix for
5626 loading absolute shared library symbol files, and the search path for
5627 locating non-absolute shared library symbol files.
5629 * Live range splitting
5631 GDB can now effectively debug code for which GCC has performed live
5632 range splitting as part of its optimization. See gdb/doc/LRS for
5633 more details on the expected format of the stabs information.
5637 GDB's support for the GNU Hurd, including thread debugging, has been
5638 updated to work with current versions of the Hurd.
5642 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5643 instruction set. ARM GDB automatically detects when Thumb
5644 instructions are in use, and adjusts disassembly and backtracing
5649 GDB's MIPS target configurations now handle the MIP16 16-bit
5654 GDB now includes support for overlays; if an executable has been
5655 linked such that multiple sections are based at the same address, GDB
5656 will decide which section to use for symbolic info. You can choose to
5657 control the decision manually, using overlay commands, or implement
5658 additional target-side support and use "overlay load-target" to bring
5659 in the overlay mapping. Do "help overlay" for more detail.
5663 The command "info symbol <address>" displays information about
5664 the symbol at the specified address.
5668 The standard remote protocol now includes an extension that allows
5669 asynchronous collection and display of trace data. This requires
5670 extensive support in the target-side debugging stub. Tracing mode
5671 includes a new interaction mode in GDB and new commands: see the
5672 file tracepoint.c for more details.
5676 Configurations for embedded MIPS now include a simulator contributed
5677 by Cygnus Solutions. The simulator supports the instruction sets
5678 of most MIPS variants.
5682 Sparc configurations may now include the ERC32 simulator contributed
5683 by the European Space Agency. The simulator is not built into
5684 Sparc targets by default; configure with --enable-sim to include it.
5688 For target configurations that may include multiple variants of a
5689 basic architecture (such as MIPS and SH), you may now set the
5690 architecture explicitly. "set arch" sets, "info arch" lists
5691 the possible architectures.
5693 *** Changes in GDB-4.16:
5695 * New native configurations
5697 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5698 M68K NetBSD m68k-*-netbsd*
5699 PowerPC AIX 4.x powerpc-*-aix*
5700 PowerPC MacOS powerpc-*-macos*
5701 PowerPC Windows NT powerpcle-*-cygwin32
5702 RS/6000 AIX 4.x rs6000-*-aix4*
5706 ARM with RDP protocol arm-*-*
5707 I960 with MON960 i960-*-coff
5708 MIPS VxWorks mips*-*-vxworks*
5709 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5710 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5712 Matra Sparclet sparclet-*-*
5716 The powerpc-eabi configuration now includes the PSIM simulator,
5717 contributed by Andrew Cagney, with assistance from Mike Meissner.
5718 PSIM is a very elaborate model of the PowerPC, including not only
5719 basic instruction set execution, but also details of execution unit
5720 performance and I/O hardware. See sim/ppc/README for more details.
5724 GDB now works with Solaris 2.5.
5726 * Windows 95/NT native
5728 GDB will now work as a native debugger on Windows 95 and Windows NT.
5729 To build it from source, you must use the "gnu-win32" environment,
5730 which uses a DLL to emulate enough of Unix to run the GNU tools.
5731 Further information, binaries, and sources are available at
5732 ftp.cygnus.com, under pub/gnu-win32.
5734 * dont-repeat command
5736 If a user-defined command includes the command `dont-repeat', then the
5737 command will not be repeated if the user just types return. This is
5738 useful if the command is time-consuming to run, so that accidental
5739 extra keystrokes don't run the same command many times.
5741 * Send break instead of ^C
5743 The standard remote protocol now includes an option to send a break
5744 rather than a ^C to the target in order to interrupt it. By default,
5745 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5747 * Remote protocol timeout
5749 The standard remote protocol includes a new variable `remotetimeout'
5750 that allows you to set the number of seconds before GDB gives up trying
5751 to read from the target. The default value is 2.
5753 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5755 By default GDB will automatically keep track of objects as they are
5756 loaded and unloaded by the dynamic linker. By using the command `set
5757 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5758 when shared library events occur, thus allowing you to set breakpoints
5759 in shared libraries which are explicitly loaded by the inferior.
5761 Note this feature does not work on hpux8. On hpux9 you must link
5762 /usr/lib/end.o into your program. This feature should work
5763 automatically on hpux10.
5765 * Irix 5.x hardware watchpoint support
5767 Irix 5 configurations now support the use of hardware watchpoints.
5769 * Mips protocol "SYN garbage limit"
5771 When debugging a Mips target using the `target mips' protocol, you
5772 may set the number of characters that GDB will ignore by setting
5773 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5774 every character. The default value is 1050.
5776 * Recording and replaying remote debug sessions
5778 If you set `remotelogfile' to the name of a file, gdb will write to it
5779 a recording of a remote debug session. This recording may then be
5780 replayed back to gdb using "gdbreplay". See gdbserver/README for
5781 details. This is useful when you have a problem with GDB while doing
5782 remote debugging; you can make a recording of the session and send it
5783 to someone else, who can then recreate the problem.
5785 * Speedups for remote debugging
5787 GDB includes speedups for downloading and stepping MIPS systems using
5788 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5789 and more efficient S-record downloading.
5791 * Memory use reductions and statistics collection
5793 GDB now uses less memory and reports statistics about memory usage.
5794 Try the `maint print statistics' command, for example.
5796 *** Changes in GDB-4.15:
5798 * Psymtabs for XCOFF
5800 The symbol reader for AIX GDB now uses partial symbol tables. This
5801 can greatly improve startup time, especially for large executables.
5803 * Remote targets use caching
5805 Remote targets now use a data cache to speed up communication with the
5806 remote side. The data cache could lead to incorrect results because
5807 it doesn't know about volatile variables, thus making it impossible to
5808 debug targets which use memory mapped I/O devices. `set remotecache
5809 off' turns the the data cache off.
5811 * Remote targets may have threads
5813 The standard remote protocol now includes support for multiple threads
5814 in the target system, using new protocol commands 'H' and 'T'. See
5815 gdb/remote.c for details.
5819 If GDB is configured with `--enable-netrom', then it will include
5820 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5821 acts as though it is a bank of ROM on the target board, but you can
5822 write into it over the network. GDB's support consists only of
5823 support for fast loading into the emulated ROM; to debug, you must use
5824 another protocol, such as standard remote protocol. The usual
5825 sequence is something like
5827 target nrom <netrom-hostname>
5829 target remote <netrom-hostname>:1235
5833 GDB now includes support for the Apple Macintosh, as a host only. It
5834 may be run as either an MPW tool or as a standalone application, and
5835 it can debug through the serial port. All the usual GDB commands are
5836 available, but to the target command, you must supply "serial" as the
5837 device type instead of "/dev/ttyXX". See mpw-README in the main
5838 directory for more information on how to build. The MPW configuration
5839 scripts */mpw-config.in support only a few targets, and only the
5840 mips-idt-ecoff target has been tested.
5844 GDB configuration now uses autoconf. This is not user-visible,
5845 but does simplify configuration and building.
5849 GDB now supports hpux10.
5851 *** Changes in GDB-4.14:
5853 * New native configurations
5855 x86 FreeBSD i[345]86-*-freebsd
5856 x86 NetBSD i[345]86-*-netbsd
5857 NS32k NetBSD ns32k-*-netbsd
5858 Sparc NetBSD sparc-*-netbsd
5862 A29K VxWorks a29k-*-vxworks
5863 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5864 CPU32 EST-300 emulator m68*-*-est*
5865 PowerPC ELF powerpc-*-elf
5868 * Alpha OSF/1 support for procfs
5870 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5871 possible to attach to running processes. As the mounting of the /proc
5872 filesystem is optional on the Alpha, GDB automatically determines
5873 the availability of /proc during startup. This can lead to problems
5874 if /proc is unmounted after GDB has been started.
5876 * Arguments to user-defined commands
5878 User commands may accept up to 10 arguments separated by whitespace.
5879 Arguments are accessed within the user command via $arg0..$arg9. A
5882 print $arg0 + $arg1 + $arg2
5884 To execute the command use:
5887 Defines the command "adder" which prints the sum of its three arguments.
5888 Note the arguments are text substitutions, so they may reference variables,
5889 use complex expressions, or even perform inferior function calls.
5891 * New `if' and `while' commands
5893 This makes it possible to write more sophisticated user-defined
5894 commands. Both commands take a single argument, which is the
5895 expression to evaluate, and must be followed by the commands to
5896 execute, one per line, if the expression is nonzero, the list being
5897 terminated by the word `end'. The `if' command list may include an
5898 `else' word, which causes the following commands to be executed only
5899 if the expression is zero.
5901 * Fortran source language mode
5903 GDB now includes partial support for Fortran 77. It will recognize
5904 Fortran programs and can evaluate a subset of Fortran expressions, but
5905 variables and functions may not be handled correctly. GDB will work
5906 with G77, but does not yet know much about symbols emitted by other
5909 * Better HPUX support
5911 Most debugging facilities now work on dynamic executables for HPPAs
5912 running hpux9 or later. You can attach to running dynamically linked
5913 processes, but by default the dynamic libraries will be read-only, so
5914 for instance you won't be able to put breakpoints in them. To change
5915 that behavior do the following before running the program:
5921 This will cause the libraries to be mapped private and read-write.
5922 To revert to the normal behavior, do this:
5928 You cannot set breakpoints or examine data in the library until after
5929 the library is loaded if the function/data symbols do not have
5932 GDB can now also read debug symbols produced by the HP C compiler on
5933 HPPAs (sorry, no C++, Fortran or 68k support).
5935 * Target byte order now dynamically selectable
5937 You can choose which byte order to use with a target system, via the
5938 commands "set endian big" and "set endian little", and you can see the
5939 current setting by using "show endian". You can also give the command
5940 "set endian auto", in which case GDB will use the byte order
5941 associated with the executable. Currently, only embedded MIPS
5942 configurations support dynamic selection of target byte order.
5944 * New DOS host serial code
5946 This version uses DPMI interrupts to handle buffered I/O, so you
5947 no longer need to run asynctsr when debugging boards connected to
5950 *** Changes in GDB-4.13:
5952 * New "complete" command
5954 This lists all the possible completions for the rest of the line, if it
5955 were to be given as a command itself. This is intended for use by emacs.
5957 * Trailing space optional in prompt
5959 "set prompt" no longer adds a space for you after the prompt you set. This
5960 allows you to set a prompt which ends in a space or one that does not.
5962 * Breakpoint hit counts
5964 "info break" now displays a count of the number of times the breakpoint
5965 has been hit. This is especially useful in conjunction with "ignore"; you
5966 can ignore a large number of breakpoint hits, look at the breakpoint info
5967 to see how many times the breakpoint was hit, then run again, ignoring one
5968 less than that number, and this will get you quickly to the last hit of
5971 * Ability to stop printing at NULL character
5973 "set print null-stop" will cause GDB to stop printing the characters of
5974 an array when the first NULL is encountered. This is useful when large
5975 arrays actually contain only short strings.
5977 * Shared library breakpoints
5979 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5980 breakpoints in shared libraries before the executable is run.
5982 * Hardware watchpoints
5984 There is a new hardware breakpoint for the watch command for sparclite
5985 targets. See gdb/sparclite/hw_breakpoint.note.
5987 Hardware watchpoints are also now supported under GNU/Linux.
5991 Annotations have been added. These are for use with graphical interfaces,
5992 and are still experimental. Currently only gdba.el uses these.
5994 * Improved Irix 5 support
5996 GDB now works properly with Irix 5.2.
5998 * Improved HPPA support
6000 GDB now works properly with the latest GCC and GAS.
6002 * New native configurations
6004 Sequent PTX4 i[34]86-sequent-ptx4
6005 HPPA running OSF/1 hppa*-*-osf*
6006 Atari TT running SVR4 m68*-*-sysv4*
6007 RS/6000 LynxOS rs6000-*-lynxos*
6011 OS/9000 i[34]86-*-os9k
6012 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6015 * Hitachi SH7000 and E7000-PC ICE support
6017 There is now support for communicating with the Hitachi E7000-PC ICE.
6018 This is available automatically when GDB is configured for the SH.
6022 As usual, a variety of small fixes and improvements, both generic
6023 and configuration-specific. See the ChangeLog for more detail.
6025 *** Changes in GDB-4.12:
6027 * Irix 5 is now supported
6031 GDB-4.12 on the HPPA has a number of changes which make it unable
6032 to debug the output from the currently released versions of GCC and
6033 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6034 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6035 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6038 *** Changes in GDB-4.11:
6040 * User visible changes:
6044 The "set remotedebug" option is now consistent between the mips remote
6045 target, remote targets using the gdb-specific protocol, UDI (AMD's
6046 debug protocol for the 29k) and the 88k bug monitor. It is now an
6047 integer specifying a debug level (normally 0 or 1, but 2 means more
6048 debugging info for the mips target).
6050 * DEC Alpha native support
6052 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6053 debug info, but GDB works fairly well with the DEC compiler and should
6054 work with a future GCC release. See the README file for a few
6055 Alpha-specific notes.
6057 * Preliminary thread implementation
6059 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6061 * LynxOS native and target support for 386
6063 This release has been hosted on LynxOS 2.2, and also can be configured
6064 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6067 * Improvements in C++ mangling/demangling.
6069 This release has much better g++ debugging, specifically in name
6070 mangling/demangling, virtual function calls, print virtual table,
6071 call methods, ...etc.
6073 *** Changes in GDB-4.10:
6075 * User visible changes:
6077 Remote debugging using the GDB-specific (`target remote') protocol now
6078 supports the `load' command. This is only useful if you have some
6079 other way of getting the stub to the target system, and you can put it
6080 somewhere in memory where it won't get clobbered by the download.
6082 Filename completion now works.
6084 When run under emacs mode, the "info line" command now causes the
6085 arrow to point to the line specified. Also, "info line" prints
6086 addresses in symbolic form (as well as hex).
6088 All vxworks based targets now support a user settable option, called
6089 vxworks-timeout. This option represents the number of seconds gdb
6090 should wait for responses to rpc's. You might want to use this if
6091 your vxworks target is, perhaps, a slow software simulator or happens
6092 to be on the far side of a thin network line.
6096 This release contains support for using a DEC alpha as a GDB host for
6097 cross debugging. Native alpha debugging is not supported yet.
6100 *** Changes in GDB-4.9:
6104 This is the first GDB release which is accompanied by a matching testsuite.
6105 The testsuite requires installation of dejagnu, which should be available
6106 via ftp from most sites that carry GNU software.
6110 'Cfront' style demangling has had its name changed to 'ARM' style, to
6111 emphasize that it was written from the specifications in the C++ Annotated
6112 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6113 disclaimers, it still generated too much confusion with users attempting to
6114 use gdb with AT&T cfront.
6118 GDB now uses a standard remote interface to a simulator library.
6119 So far, the library contains simulators for the Zilog Z8001/2, the
6120 Hitachi H8/300, H8/500 and Super-H.
6122 * New targets supported
6124 H8/300 simulator h8300-hitachi-hms or h8300hms
6125 H8/500 simulator h8500-hitachi-hms or h8500hms
6126 SH simulator sh-hitachi-hms or sh
6127 Z8000 simulator z8k-zilog-none or z8ksim
6128 IDT MIPS board over serial line mips-idt-ecoff
6130 Cross-debugging to GO32 targets is supported. It requires a custom
6131 version of the i386-stub.c module which is integrated with the
6132 GO32 memory extender.
6134 * New remote protocols
6136 MIPS remote debugging protocol.
6138 * New source languages supported
6140 This version includes preliminary support for Chill, a Pascal like language
6141 used by telecommunications companies. Chill support is also being integrated
6142 into the GNU compiler, but we don't know when it will be publically available.
6145 *** Changes in GDB-4.8:
6147 * HP Precision Architecture supported
6149 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6150 version of this support was available as a set of patches from the
6151 University of Utah. GDB does not support debugging of programs
6152 compiled with the HP compiler, because HP will not document their file
6153 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6154 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6156 Many problems in the preliminary version have been fixed.
6158 * Faster and better demangling
6160 We have improved template demangling and fixed numerous bugs in the GNU style
6161 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6162 character types (wchar_t) are now supported. Demangling of each symbol is now
6163 only done once, and is cached when the symbol table for a file is read in.
6164 This results in a small increase in memory usage for C programs, a moderate
6165 increase in memory usage for C++ programs, and a fantastic speedup in
6168 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6169 from the specifications in the Annotated Reference Manual, which AT&T's
6170 compiler does not actually implement.
6172 * G++ multiple inheritance compiler problem
6174 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6175 inheritance lattices was reworked to properly discover ambiguities. We
6176 recently found an example which causes this new algorithm to fail in a
6177 very subtle way, producing bad debug information for those classes.
6178 The file 'gcc.patch' (in this directory) can be applied to gcc to
6179 circumvent the problem. A future GCC release will contain a complete
6182 The previous G++ debug info problem (mentioned below for the gdb-4.7
6183 release) is fixed in gcc version 2.3.2.
6185 * Improved configure script
6187 The `configure' script will now attempt to guess your system type if
6188 you don't supply a host system type. The old scheme of supplying a
6189 host system triplet is preferable over using this. All the magic is
6190 done in the new `config.guess' script. Examine it for details.
6192 We have also brought our configure script much more in line with the FSF's
6193 version. It now supports the --with-xxx options. In particular,
6194 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6195 The resulting GDB will not be able to read arbitrary object file formats --
6196 only the format ``expected'' to be used on the configured target system.
6197 We hope to make this the default in a future release.
6199 * Documentation improvements
6201 There's new internal documentation on how to modify GDB, and how to
6202 produce clean changes to the code. We implore people to read it
6203 before submitting changes.
6205 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6206 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6207 `info' files are also provided. To build `info' files from scratch,
6208 you will need the latest `makeinfo' release, which will be available in
6209 a future texinfo-X.Y release.
6211 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6212 We're not sure exactly which versions have this problem, but it has
6213 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6214 or better. If that isn't possible, there is a patch in
6215 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6216 around this problem.
6220 GDB now supports array constants that can be used in expressions typed in by
6221 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6222 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6225 The new directory `gdb/sparclite' contains a program that demonstrates
6226 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6228 * New native hosts supported
6230 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6231 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6233 * New targets supported
6235 AMD 29k family via UDI a29k-amd-udi or udi29k
6237 * New file formats supported
6239 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6240 HPUX core files, and SCO 3.2v2 core files.
6244 Attaching to processes now works again; thanks for the many bug reports.
6246 We have also stomped on a bunch of core dumps caused by
6247 printf_filtered("%s") problems.
6249 We eliminated a copyright problem on the rpc and ptrace header files
6250 for VxWorks, which was discovered at the last minute during the 4.7
6251 release. You should now be able to build a VxWorks GDB.
6253 You can now interrupt gdb while an attached process is running. This
6254 will cause the attached process to stop, and give control back to GDB.
6256 We fixed problems caused by using too many file descriptors
6257 for reading symbols from object files and libraries. This was
6258 especially a problem for programs that used many (~100) shared
6261 The `step' command now only enters a subroutine if there is line number
6262 information for the subroutine. Otherwise it acts like the `next'
6263 command. Previously, `step' would enter subroutines if there was
6264 any debugging information about the routine. This avoids problems
6265 when using `cc -g1' on MIPS machines.
6267 * Internal improvements
6269 GDB's internal interfaces have been improved to make it easier to support
6270 debugging of multiple languages in the future.
6272 GDB now uses a common structure for symbol information internally.
6273 Minimal symbols (derived from linkage symbols in object files), partial
6274 symbols (from a quick scan of debug information), and full symbols
6275 contain a common subset of information, making it easier to write
6276 shared code that handles any of them.
6278 * New command line options
6280 We now accept --silent as an alias for --quiet.
6284 The memory-mapped-malloc library is now licensed under the GNU Library
6285 General Public License.
6287 *** Changes in GDB-4.7:
6289 * Host/native/target split
6291 GDB has had some major internal surgery to untangle the support for
6292 hosts and remote targets. Now, when you configure GDB for a remote
6293 target, it will no longer load in all of the support for debugging
6294 local programs on the host. When fully completed and tested, this will
6295 ensure that arbitrary host/target combinations are possible.
6297 The primary conceptual shift is to separate the non-portable code in
6298 GDB into three categories. Host specific code is required any time GDB
6299 is compiled on that host, regardless of the target. Target specific
6300 code relates to the peculiarities of the target, but can be compiled on
6301 any host. Native specific code is everything else: it can only be
6302 built when the host and target are the same system. Child process
6303 handling and core file support are two common `native' examples.
6305 GDB's use of /proc for controlling Unix child processes is now cleaner.
6306 It has been split out into a single module under the `target_ops' vector,
6307 plus two native-dependent functions for each system that uses /proc.
6309 * New hosts supported
6311 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6312 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6313 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6315 * New targets supported
6317 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6318 68030 and CPU32 m68030-*-*, m68332-*-*
6320 * New native hosts supported
6322 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6323 (386bsd is not well tested yet)
6324 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6326 * New file formats supported
6328 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6329 supports reading of `a.out.adobe' object files, which are an a.out
6330 format extended with minimal information about multiple sections.
6334 `show copying' is the same as the old `info copying'.
6335 `show warranty' is the same as `info warrantee'.
6336 These were renamed for consistency. The old commands continue to work.
6338 `info handle' is a new alias for `info signals'.
6340 You can now define pre-command hooks, which attach arbitrary command
6341 scripts to any command. The commands in the hook will be executed
6342 prior to the user's command. You can also create a hook which will be
6343 executed whenever the program stops. See gdb.texinfo.
6347 We now deal with Cfront style name mangling, and can even extract type
6348 info from mangled symbols. GDB can automatically figure out which
6349 symbol mangling style your C++ compiler uses.
6351 Calling of methods and virtual functions has been improved as well.
6355 The crash that occured when debugging Sun Ansi-C compiled binaries is
6356 fixed. This was due to mishandling of the extra N_SO stabs output
6359 We also finally got Ultrix 4.2 running in house, and fixed core file
6360 support, with help from a dozen people on the net.
6362 John M. Farrell discovered that the reason that single-stepping was so
6363 slow on all of the Mips based platforms (primarily SGI and DEC) was
6364 that we were trying to demangle and lookup a symbol used for internal
6365 purposes on every instruction that was being stepped through. Changing
6366 the name of that symbol so that it couldn't be mistaken for a C++
6367 mangled symbol sped things up a great deal.
6369 Rich Pixley sped up symbol lookups in general by getting much smarter
6370 about when C++ symbol mangling is necessary. This should make symbol
6371 completion (TAB on the command line) much faster. It's not as fast as
6372 we'd like, but it's significantly faster than gdb-4.6.
6376 A new user controllable variable 'call_scratch_address' can
6377 specify the location of a scratch area to be used when GDB
6378 calls a function in the target. This is necessary because the
6379 usual method of putting the scratch area on the stack does not work
6380 in systems that have separate instruction and data spaces.
6382 We integrated changes to support the 29k UDI (Universal Debugger
6383 Interface), but discovered at the last minute that we didn't have all
6384 of the appropriate copyright paperwork. We are working with AMD to
6385 resolve this, and hope to have it available soon.
6389 We have sped up the remote serial line protocol, especially for targets
6390 with lots of registers. It now supports a new `expedited status' ('T')
6391 message which can be used in place of the existing 'S' status message.
6392 This allows the remote stub to send only the registers that GDB
6393 needs to make a quick decision about single-stepping or conditional
6394 breakpoints, eliminating the need to fetch the entire register set for
6395 each instruction being stepped through.
6397 The GDB remote serial protocol now implements a write-through cache for
6398 registers, only re-reading the registers if the target has run.
6400 There is also a new remote serial stub for SPARC processors. You can
6401 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6402 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6403 processor with a serial port.
6407 Configure.in files have become much easier to read and modify. A new
6408 `table driven' format makes it more obvious what configurations are
6409 supported, and what files each one uses.
6413 There is a new opcodes library which will eventually contain all of the
6414 disassembly routines and opcode tables. At present, it only contains
6415 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6416 disassembler (binutils/objdump) to share these routines.
6418 The libiberty library is now copylefted under the GNU Library General
6419 Public License. This allows more liberal use, and was done so libg++
6420 can use it. This makes no difference to GDB, since the Library License
6421 grants all the rights from the General Public License.
6425 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6426 reference to the stabs symbol info used by the debugger. It is (as far
6427 as we know) the only published document on this fascinating topic. We
6428 encourage you to read it, compare it to the stabs information on your
6429 system, and send improvements on the document in general (to
6430 bug-gdb@prep.ai.mit.edu).
6432 And, of course, many bugs have been fixed.
6435 *** Changes in GDB-4.6:
6437 * Better support for C++ function names
6439 GDB now accepts as input the "demangled form" of C++ overloaded function
6440 names and member function names, and can do command completion on such names
6441 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6442 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6443 Make use of command completion, it is your friend.
6445 GDB also now accepts a variety of C++ mangled symbol formats. They are
6446 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6447 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6448 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6449 for the list of formats.
6451 * G++ symbol mangling problem
6453 Recent versions of gcc have a bug in how they emit debugging information for
6454 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6455 directory) can be applied to gcc to fix the problem. Alternatively, if you
6456 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6457 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6458 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6461 * New 'maintenance' command
6463 All of the commands related to hacking GDB internals have been moved out of
6464 the main command set, and now live behind the 'maintenance' command. This
6465 can also be abbreviated as 'mt'. The following changes were made:
6467 dump-me -> maintenance dump-me
6468 info all-breakpoints -> maintenance info breakpoints
6469 printmsyms -> maintenance print msyms
6470 printobjfiles -> maintenance print objfiles
6471 printpsyms -> maintenance print psymbols
6472 printsyms -> maintenance print symbols
6474 The following commands are new:
6476 maintenance demangle Call internal GDB demangler routine to
6477 demangle a C++ link name and prints the result.
6478 maintenance print type Print a type chain for a given symbol
6480 * Change to .gdbinit file processing
6482 We now read the $HOME/.gdbinit file before processing the argv arguments
6483 (e.g. reading symbol files or core files). This allows global parameters to
6484 be set, which will apply during the symbol reading. The ./.gdbinit is still
6485 read after argv processing.
6487 * New hosts supported
6489 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6491 GNU/Linux support i386-unknown-linux or linux
6493 We are also including code to support the HP/PA running BSD and HPUX. This
6494 is almost guaranteed not to work, as we didn't have time to test or build it
6495 for this release. We are including it so that the more adventurous (or
6496 masochistic) of you can play with it. We also had major problems with the
6497 fact that the compiler that we got from HP doesn't support the -g option.
6500 * New targets supported
6502 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6504 * More smarts about finding #include files
6506 GDB now remembers the compilation directory for all include files, and for
6507 all files from which C is generated (like yacc and lex sources). This
6508 greatly improves GDB's ability to find yacc/lex sources, and include files,
6509 especially if you are debugging your program from a directory different from
6510 the one that contains your sources.
6512 We also fixed a bug which caused difficulty with listing and setting
6513 breakpoints in include files which contain C code. (In the past, you had to
6514 try twice in order to list an include file that you hadn't looked at before.)
6516 * Interesting infernals change
6518 GDB now deals with arbitrary numbers of sections, where the symbols for each
6519 section must be relocated relative to that section's landing place in the
6520 target's address space. This work was needed to support ELF with embedded
6521 stabs used by Solaris-2.0.
6523 * Bug fixes (of course!)
6525 There have been loads of fixes for the following things:
6526 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6527 i960, stabs, DOS(GO32), procfs, etc...
6529 See the ChangeLog for details.
6531 *** Changes in GDB-4.5:
6533 * New machines supported (host and target)
6535 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6537 SGI Irix-4.x mips-sgi-irix4 or iris4
6539 * New malloc package
6541 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6542 Mmalloc is capable of handling mutiple heaps of memory. It is also
6543 capable of saving a heap to a file, and then mapping it back in later.
6544 This can be used to greatly speedup the startup of GDB by using a
6545 pre-parsed symbol table which lives in a mmalloc managed heap. For
6546 more details, please read mmalloc/mmalloc.texi.
6550 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6551 'help info proc' for details.
6553 * MIPS ecoff symbol table format
6555 The code that reads MIPS symbol table format is now supported on all hosts.
6556 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6559 * File name changes for MS-DOS
6561 Many files in the config directories have been renamed to make it easier to
6562 support GDB on MS-DOSe systems (which have very restrictive file name
6563 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6564 environment) is close to working but has some remaining problems. Note
6565 that debugging of DOS programs is not supported, due to limitations
6566 in the ``operating system'', but it can be used to host cross-debugging.
6568 * Cross byte order fixes
6570 Many fixes have been made to support cross debugging of Sparc and MIPS
6571 targets from hosts whose byte order differs.
6573 * New -mapped and -readnow options
6575 If memory-mapped files are available on your system through the 'mmap'
6576 system call, you can use the -mapped option on the `file' or
6577 `symbol-file' commands to cause GDB to write the symbols from your
6578 program into a reusable file. If the program you are debugging is
6579 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6580 Future GDB debugging sessions will notice the presence of this file,
6581 and will quickly map in symbol information from it, rather than reading
6582 the symbol table from the executable program. Using the '-mapped'
6583 option in a GDB `file' or `symbol-file' command has the same effect as
6584 starting GDB with the '-mapped' command-line option.
6586 You can cause GDB to read the entire symbol table immediately by using
6587 the '-readnow' option with any of the commands that load symbol table
6588 information (or on the GDB command line). This makes the command
6589 slower, but makes future operations faster.
6591 The -mapped and -readnow options are typically combined in order to
6592 build a `fred.syms' file that contains complete symbol information.
6593 A simple GDB invocation to do nothing but build a `.syms' file for future
6596 gdb -batch -nx -mapped -readnow programname
6598 The `.syms' file is specific to the host machine on which GDB is run.
6599 It holds an exact image of GDB's internal symbol table. It cannot be
6600 shared across multiple host platforms.
6602 * longjmp() handling
6604 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6605 siglongjmp() without losing control. This feature has not yet been ported to
6606 all systems. It currently works on many 386 platforms, all MIPS-based
6607 platforms (SGI, DECstation, etc), and Sun3/4.
6611 Preliminary work has been put in to support the new Solaris OS from Sun. At
6612 this time, it can control and debug processes, but it is not capable of
6617 As always, many many bug fixes. The major areas were with g++, and mipsread.
6618 People using the MIPS-based platforms should experience fewer mysterious
6619 crashes and trashed symbol tables.
6621 *** Changes in GDB-4.4:
6623 * New machines supported (host and target)
6625 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6627 BSD Reno on Vax vax-dec-bsd
6628 Ultrix on Vax vax-dec-ultrix
6630 * New machines supported (target)
6632 AMD 29000 embedded, using EBMON a29k-none-none
6636 GDB continues to improve its handling of C++. `References' work better.
6637 The demangler has also been improved, and now deals with symbols mangled as
6638 per the Annotated C++ Reference Guide.
6640 GDB also now handles `stabs' symbol information embedded in MIPS
6641 `ecoff' symbol tables. Since the ecoff format was not easily
6642 extensible to handle new languages such as C++, this appeared to be a
6643 good way to put C++ debugging info into MIPS binaries. This option
6644 will be supported in the GNU C compiler, version 2, when it is
6647 * New features for SVR4
6649 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6650 shared libraries. Debugging dynamically linked programs should present
6651 only minor differences from debugging statically linked programs.
6653 The `info proc' command will print out information about any process
6654 on an SVR4 system (including the one you are debugging). At the moment,
6655 it prints the address mappings of the process.
6657 If you bring up GDB on another SVR4 system, please send mail to
6658 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6660 * Better dynamic linking support in SunOS
6662 Reading symbols from shared libraries which contain debugging symbols
6663 now works properly. However, there remain issues such as automatic
6664 skipping of `transfer vector' code during function calls, which
6665 make it harder to debug code in a shared library, than to debug the
6666 same code linked statically.
6670 GDB is now using the latest `getopt' routines from the FSF. This
6671 version accepts the -- prefix for options with long names. GDB will
6672 continue to accept the old forms (-option and +option) as well.
6673 Various single letter abbreviations for options have been explicity
6674 added to the option table so that they won't get overshadowed in the
6675 future by other options that begin with the same letter.
6679 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6680 Many assorted bugs have been handled. Many more remain to be handled.
6681 See the various ChangeLog files (primarily in gdb and bfd) for details.
6684 *** Changes in GDB-4.3:
6686 * New machines supported (host and target)
6688 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6689 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6690 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6692 * Almost SCO Unix support
6694 We had hoped to support:
6695 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6696 (except for core file support), but we discovered very late in the release
6697 that it has problems with process groups that render gdb unusable. Sorry
6698 about that. I encourage people to fix it and post the fixes.
6700 * Preliminary ELF and DWARF support
6702 GDB can read ELF object files on System V Release 4, and can handle
6703 debugging records for C, in DWARF format, in ELF files. This support
6704 is preliminary. If you bring up GDB on another SVR4 system, please
6705 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6710 GDB now uses the latest `readline' library. One user-visible change
6711 is that two tabs will list possible command completions, which previously
6712 required typing M-? (meta-question mark, or ESC ?).
6716 The `stepi' bug that many of you noticed has been squashed.
6717 Many bugs in C++ have been handled. Many more remain to be handled.
6718 See the various ChangeLog files (primarily in gdb and bfd) for details.
6720 * State of the MIPS world (in case you wondered):
6722 GDB can understand the symbol tables emitted by the compilers
6723 supplied by most vendors of MIPS-based machines, including DEC. These
6724 symbol tables are in a format that essentially nobody else uses.
6726 Some versions of gcc come with an assembler post-processor called
6727 mips-tfile. This program is required if you want to do source-level
6728 debugging of gcc-compiled programs. I believe FSF does not ship
6729 mips-tfile with gcc version 1, but it will eventually come with gcc
6732 Debugging of g++ output remains a problem. g++ version 1.xx does not
6733 really support it at all. (If you're lucky, you should be able to get
6734 line numbers and stack traces to work, but no parameters or local
6735 variables.) With some work it should be possible to improve the
6738 When gcc version 2 is released, you will have somewhat better luck.
6739 However, even then you will get confusing results for inheritance and
6742 We will eventually provide full debugging of g++ output on
6743 DECstations. This will probably involve some kind of stabs-in-ecoff
6744 encapulation, but the details have not been worked out yet.
6747 *** Changes in GDB-4.2:
6749 * Improved configuration
6751 Only one copy of `configure' exists now, and it is not self-modifying.
6752 Porting BFD is simpler.
6756 The `step' and `next' commands now only stop at the first instruction
6757 of a source line. This prevents the multiple stops that used to occur
6758 in switch statements, for-loops, etc. `Step' continues to stop if a
6759 function that has debugging information is called within the line.
6763 Lots of small bugs fixed. More remain.
6765 * New host supported (not target)
6767 Intel 386 PC clone running Mach i386-none-mach
6770 *** Changes in GDB-4.1:
6772 * Multiple source language support
6774 GDB now has internal scaffolding to handle several source languages.
6775 It determines the type of each source file from its filename extension,
6776 and will switch expression parsing and number formatting to match the
6777 language of the function in the currently selected stack frame.
6778 You can also specifically set the language to be used, with
6779 `set language c' or `set language modula-2'.
6783 GDB now has preliminary support for the GNU Modula-2 compiler,
6784 currently under development at the State University of New York at
6785 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6786 continue through the fall of 1991 and into 1992.
6788 Other Modula-2 compilers are currently not supported, and attempting to
6789 debug programs compiled with them will likely result in an error as the
6790 symbol table is read. Feel free to work on it, though!
6792 There are hooks in GDB for strict type checking and range checking,
6793 in the `Modula-2 philosophy', but they do not currently work.
6797 GDB can now write to executable and core files (e.g. patch
6798 a variable's value). You must turn this switch on, specify
6799 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6800 by assigning a new value to a variable. Modifications take
6803 * Automatic SunOS shared library reading
6805 When you run your program, GDB automatically determines where its
6806 shared libraries (if any) have been loaded, and reads their symbols.
6807 The `share' command is no longer needed. This also works when
6808 examining core files.
6812 You can specify the number of lines that the `list' command shows.
6815 * New machines supported (host and target)
6817 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6818 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6819 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6821 * New hosts supported (not targets)
6823 IBM RT/PC: romp-ibm-aix or rtpc
6825 * New targets supported (not hosts)
6827 AMD 29000 embedded with COFF a29k-none-coff
6828 AMD 29000 embedded with a.out a29k-none-aout
6829 Ultracomputer remote kernel debug a29k-nyu-kern
6831 * New remote interfaces
6837 *** Changes in GDB-4.0:
6841 Wide output is wrapped at good places to make the output more readable.
6843 Gdb now supports cross-debugging from a host machine of one type to a
6844 target machine of another type. Communication with the target system
6845 is over serial lines. The ``target'' command handles connecting to the
6846 remote system; the ``load'' command will download a program into the
6847 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6848 also supports debugging of realtime processes running under VxWorks,
6849 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6850 stub on the target system.
6852 New CPUs supported include the AMD 29000 and Intel 960.
6854 GDB now reads object files and symbol tables via a ``binary file''
6855 library, which allows a single copy of GDB to debug programs of multiple
6856 object file types such as a.out and coff.
6858 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6859 refcard.dvi and refcard.ps are available to format it).
6862 * Control-Variable user interface simplified
6864 All variables that control the operation of the debugger can be set
6865 by the ``set'' command, and displayed by the ``show'' command.
6867 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6868 ``Show prompt'' produces the response:
6869 Gdb's prompt is new-gdb=>.
6871 What follows are the NEW set commands. The command ``help set'' will
6872 print a complete list of old and new set commands. ``help set FOO''
6873 will give a longer description of the variable FOO. ``show'' will show
6874 all of the variable descriptions and their current settings.
6876 confirm on/off: Enables warning questions for operations that are
6877 hard to recover from, e.g. rerunning the program while
6878 it is already running. Default is ON.
6880 editing on/off: Enables EMACS style command line editing
6881 of input. Previous lines can be recalled with
6882 control-P, the current line can be edited with control-B,
6883 you can search for commands with control-R, etc.
6886 history filename NAME: NAME is where the gdb command history
6887 will be stored. The default is .gdb_history,
6888 or the value of the environment variable
6891 history size N: The size, in commands, of the command history. The
6892 default is 256, or the value of the environment variable
6895 history save on/off: If this value is set to ON, the history file will
6896 be saved after exiting gdb. If set to OFF, the
6897 file will not be saved. The default is OFF.
6899 history expansion on/off: If this value is set to ON, then csh-like
6900 history expansion will be performed on
6901 command line input. The default is OFF.
6903 radix N: Sets the default radix for input and output. It can be set
6904 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6905 in the current radix, so "set radix 10" is always a no-op.
6907 height N: This integer value is the number of lines on a page. Default
6908 is 24, the current `stty rows'' setting, or the ``li#''
6909 setting from the termcap entry matching the environment
6912 width N: This integer value is the number of characters on a line.
6913 Default is 80, the current `stty cols'' setting, or the ``co#''
6914 setting from the termcap entry matching the environment
6917 Note: ``set screensize'' is obsolete. Use ``set height'' and
6918 ``set width'' instead.
6920 print address on/off: Print memory addresses in various command displays,
6921 such as stack traces and structure values. Gdb looks
6922 more ``symbolic'' if you turn this off; it looks more
6923 ``machine level'' with it on. Default is ON.
6925 print array on/off: Prettyprint arrays. New convenient format! Default
6928 print demangle on/off: Print C++ symbols in "source" form if on,
6931 print asm-demangle on/off: Same, for assembler level printouts
6934 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6937 * Support for Epoch Environment.
6939 The epoch environment is a version of Emacs v18 with windowing. One
6940 new command, ``inspect'', is identical to ``print'', except that if you
6941 are running in the epoch environment, the value is printed in its own
6945 * Support for Shared Libraries
6947 GDB can now debug programs and core files that use SunOS shared libraries.
6948 Symbols from a shared library cannot be referenced
6949 before the shared library has been linked with the program (this
6950 happens after you type ``run'' and before the function main() is entered).
6951 At any time after this linking (including when examining core files
6952 from dynamically linked programs), gdb reads the symbols from each
6953 shared library when you type the ``sharedlibrary'' command.
6954 It can be abbreviated ``share''.
6956 sharedlibrary REGEXP: Load shared object library symbols for files
6957 matching a unix regular expression. No argument
6958 indicates to load symbols for all shared libraries.
6960 info sharedlibrary: Status of loaded shared libraries.
6965 A watchpoint stops execution of a program whenever the value of an
6966 expression changes. Checking for this slows down execution
6967 tremendously whenever you are in the scope of the expression, but is
6968 quite useful for catching tough ``bit-spreader'' or pointer misuse
6969 problems. Some machines such as the 386 have hardware for doing this
6970 more quickly, and future versions of gdb will use this hardware.
6972 watch EXP: Set a watchpoint (breakpoint) for an expression.
6974 info watchpoints: Information about your watchpoints.
6976 delete N: Deletes watchpoint number N (same as breakpoints).
6977 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6978 enable N: Re-enables watchpoint number N (same as breakpoints).
6981 * C++ multiple inheritance
6983 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6986 * C++ exception handling
6988 Gdb now supports limited C++ exception handling. Besides the existing
6989 ability to breakpoint on an exception handler, gdb can breakpoint on
6990 the raising of an exception (before the stack is peeled back to the
6993 catch FOO: If there is a FOO exception handler in the dynamic scope,
6994 set a breakpoint to catch exceptions which may be raised there.
6995 Multiple exceptions (``catch foo bar baz'') may be caught.
6997 info catch: Lists all exceptions which may be caught in the
6998 current stack frame.
7001 * Minor command changes
7003 The command ``call func (arg, arg, ...)'' now acts like the print
7004 command, except it does not print or save a value if the function's result
7005 is void. This is similar to dbx usage.
7007 The ``up'' and ``down'' commands now always print the frame they end up
7008 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7009 frames without printing.
7011 * New directory command
7013 'dir' now adds directories to the FRONT of the source search path.
7014 The path starts off empty. Source files that contain debug information
7015 about the directory in which they were compiled can be found even
7016 with an empty path; Sun CC and GCC include this information. If GDB can't
7017 find your source file in the current directory, type "dir .".
7019 * Configuring GDB for compilation
7021 For normal use, type ``./configure host''. See README or gdb.texinfo
7024 GDB now handles cross debugging. If you are remotely debugging between
7025 two different machines, type ``./configure host -target=targ''.
7026 Host is the machine where GDB will run; targ is the machine
7027 where the program that you are debugging will run.