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 pager now allows a "c" response, meaning to disable the pager
13 for the rest of the current command.
15 * The commands 'info variables/functions/types' now show the source line
16 numbers of symbol definitions when available.
18 * 'info proc' now works on running processes on FreeBSD systems and core
19 files created on FreeBSD systems.
21 * C expressions can now use _Alignof, and C++ expressions can now use
28 Control display of debugging info regarding the FreeBSD native target.
30 set|show varsize-limit
31 This new setting allows the user to control the maximum size of Ada
32 objects being printed when those objects have a variable type,
33 instead of that maximum size being hardcoded to 65536 bytes.
35 set|show record btrace cpu
36 Controls the processor to be used for enabling errata workarounds for
41 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
43 ** The commands attached to a breakpoint can be set by assigning to
44 the breakpoint's "commands" field.
46 ** gdb.execute can now execute multi-line gdb commands.
48 ** The new functions gdb.convenience_variable and
49 gdb.set_convenience_variable can be used to get and set the value
50 of convenience variables.
52 ** A gdb.Parameter will no longer print the "set" help text on an
53 ordinary "set"; instead by default a "set" will be silent unless
54 the get_set_string method returns a non-empty string.
58 RiscV ELF riscv*-*-elf
60 * Removed targets and native configurations
62 m88k running OpenBSD m88*-*-openbsd*
63 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
64 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
65 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
67 * Aarch64/Linux hardware watchpoints improvements
69 Hardware watchpoints on unaligned addresses are now properly
70 supported when running Linux kernel 4.10 or higher: read and access
71 watchpoints are no longer spuriously missed, and all watchpoints
72 lengths between 1 and 8 bytes are supported. On older kernels,
73 watchpoints set on unaligned addresses are no longer missed, with
74 the tradeoff that there is a possibility of false hits being
77 *** Changes in GDB 8.1
79 * GDB now supports dynamically creating arbitrary register groups specified
80 in XML target descriptions. This allows for finer grain grouping of
81 registers on systems with a large amount of registers.
83 * The 'ptype' command now accepts a '/o' flag, which prints the
84 offsets and sizes of fields in a struct, like the pahole(1) tool.
86 * New "--readnever" command line option instructs GDB to not read each
87 symbol file's symbolic debug information. This makes startup faster
88 but at the expense of not being able to perform symbolic debugging.
89 This option is intended for use cases where symbolic debugging will
90 not be used, e.g., when you only need to dump the debuggee's core.
92 * GDB now uses the GNU MPFR library, if available, to emulate target
93 floating-point arithmetic during expression evaluation when the target
94 uses different floating-point formats than the host. At least version
95 3.1 of GNU MPFR is required.
97 * GDB now supports access to the guarded-storage-control registers and the
98 software-based guarded-storage broadcast control registers on IBM z14.
100 * On Unix systems, GDB now supports transmitting environment variables
101 that are to be set or unset to GDBserver. These variables will
102 affect the environment to be passed to the remote inferior.
104 To inform GDB of environment variables that are to be transmitted to
105 GDBserver, use the "set environment" command. Only user set
106 environment variables are sent to GDBserver.
108 To inform GDB of environment variables that are to be unset before
109 the remote inferior is started by the GDBserver, use the "unset
110 environment" command.
112 * Completion improvements
114 ** GDB can now complete function parameters in linespecs and
115 explicit locations without quoting. When setting breakpoints,
116 quoting around functions names to help with TAB-completion is
117 generally no longer necessary. For example, this now completes
120 (gdb) b function(in[TAB]
121 (gdb) b function(int)
123 Related, GDB is no longer confused with completing functions in
124 C++ anonymous namespaces:
127 (gdb) b (anonymous namespace)::[TAB][TAB]
128 (anonymous namespace)::a_function()
129 (anonymous namespace)::b_function()
131 ** GDB now has much improved linespec and explicit locations TAB
132 completion support, that better understands what you're
133 completing and offers better suggestions. For example, GDB no
134 longer offers data symbols as possible completions when you're
135 setting a breakpoint.
137 ** GDB now TAB-completes label symbol names.
139 ** The "complete" command now mimics TAB completion accurately.
141 * New command line options (gcore)
144 Dump all memory mappings.
146 * Breakpoints on C++ functions are now set on all scopes by default
148 By default, breakpoints on functions/methods are now interpreted as
149 specifying all functions with the given name ignoring missing
150 leading scopes (namespaces and classes).
152 For example, assuming a C++ program with symbols named:
157 both commands "break func()" and "break B::func()" set a breakpoint
160 You can use the new flag "-qualified" to override this. This makes
161 GDB interpret the specified function name as a complete
162 fully-qualified name instead. For example, using the same C++
163 program, the "break -q B::func" command sets a breakpoint on
164 "B::func", only. A parameter has been added to the Python
165 gdb.Breakpoint constructor to achieve the same result when creating
166 a breakpoint from Python.
168 * Breakpoints on functions marked with C++ ABI tags
170 GDB can now set breakpoints on functions marked with C++ ABI tags
171 (e.g., [abi:cxx11]). See here for a description of ABI tags:
172 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
174 Functions with a C++11 abi tag are demangled/displayed like this:
176 function[abi:cxx11](int)
179 You can now set a breakpoint on such functions simply as if they had
182 (gdb) b function(int)
184 Or if you need to disambiguate between tags, like:
186 (gdb) b function[abi:other_tag](int)
188 Tab completion was adjusted accordingly as well.
192 ** New events gdb.new_inferior, gdb.inferior_deleted, and
193 gdb.new_thread are emitted. See the manual for further
194 description of these.
196 ** A new function, "gdb.rbreak" has been added to the Python API.
197 This function allows the setting of a large number of breakpoints
198 via a regex pattern in Python. See the manual for further details.
200 ** Python breakpoints can now accept explicit locations. See the
201 manual for a further description of this feature.
204 * New features in the GDB remote stub, GDBserver
206 ** GDBserver is now able to start inferior processes with a
207 specified initial working directory.
209 The user can set the desired working directory to be used from
210 GDB using the new "set cwd" command.
212 ** New "--selftest" command line option runs some GDBserver self
213 tests. These self tests are disabled in releases.
215 ** On Unix systems, GDBserver now does globbing expansion and variable
216 substitution in inferior command line arguments.
218 This is done by starting inferiors using a shell, like GDB does.
219 See "set startup-with-shell" in the user manual for how to disable
220 this from GDB when using "target extended-remote". When using
221 "target remote", you can disable the startup with shell by using the
222 new "--no-startup-with-shell" GDBserver command line option.
224 ** On Unix systems, GDBserver now supports receiving environment
225 variables that are to be set or unset from GDB. These variables
226 will affect the environment to be passed to the inferior.
228 * When catching an Ada exception raised with a message, GDB now prints
229 the message in the catchpoint hit notification. In GDB/MI mode, that
230 information is provided as an extra field named "exception-message"
231 in the *stopped notification.
233 * Trait objects can now be inspected When debugging Rust code. This
234 requires compiler support which will appear in Rust 1.24.
238 QEnvironmentHexEncoded
239 Inform GDBserver of an environment variable that is to be passed to
240 the inferior when starting it.
243 Inform GDBserver of an environment variable that is to be unset
244 before starting the remote inferior.
247 Inform GDBserver that the environment should be reset (i.e.,
248 user-set environment variables should be unset).
251 Indicates whether the inferior must be started with a shell or not.
254 Tell GDBserver that the inferior to be started should use a specific
257 * The "maintenance print c-tdesc" command now takes an optional
258 argument which is the file name of XML target description.
260 * The "maintenance selftest" command now takes an optional argument to
261 filter the tests to be run.
263 * The "enable", and "disable" commands now accept a range of
264 breakpoint locations, e.g. "enable 1.3-5".
269 Set and show the current working directory for the inferior.
272 Set and show compilation command used for compiling and injecting code
273 with the 'compile' commands.
275 set debug separate-debug-file
276 show debug separate-debug-file
277 Control the display of debug output about separate debug file search.
279 set dump-excluded-mappings
280 show dump-excluded-mappings
281 Control whether mappings marked with the VM_DONTDUMP flag should be
282 dumped when generating a core file.
285 List the registered selftests.
288 Start the debugged program stopping at the first instruction.
291 Control display of debugging messages related to OpenRISC targets.
293 set|show print type nested-type-limit
294 Set and show the limit of nesting level for nested types that the
295 type printer will show.
297 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
300 * Safer/improved support for debugging with no debug info
302 GDB no longer assumes functions with no debug information return
305 This means that GDB now refuses to call such functions unless you
306 tell it the function's type, by either casting the call to the
307 declared return type, or by casting the function to a function
308 pointer of the right type, and calling that:
310 (gdb) p getenv ("PATH")
311 'getenv' has unknown return type; cast the call to its declared return type
312 (gdb) p (char *) getenv ("PATH")
313 $1 = 0x7fffffffe "/usr/local/bin:/"...
314 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
315 $2 = 0x7fffffffe "/usr/local/bin:/"...
317 Similarly, GDB no longer assumes that global variables with no debug
318 info have type 'int', and refuses to print the variable's value
319 unless you tell it the variable's type:
322 'var' has unknown type; cast it to its declared type
326 * New native configurations
328 FreeBSD/aarch64 aarch64*-*-freebsd*
329 FreeBSD/arm arm*-*-freebsd*
333 FreeBSD/aarch64 aarch64*-*-freebsd*
334 FreeBSD/arm arm*-*-freebsd*
335 OpenRISC ELF or1k*-*-elf
337 * Removed targets and native configurations
339 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
341 *** Changes in GDB 8.0
343 * GDB now supports access to the PKU register on GNU/Linux. The register is
344 added by the Memory Protection Keys for Userspace feature which will be
345 available in future Intel CPUs.
347 * GDB now supports C++11 rvalue references.
351 ** New functions to start, stop and access a running btrace recording.
352 ** Rvalue references are now supported in gdb.Type.
354 * GDB now supports recording and replaying rdrand and rdseed Intel 64
357 * Building GDB and GDBserver now requires a C++11 compiler.
359 For example, GCC 4.8 or later.
361 It is no longer possible to build GDB or GDBserver with a C
362 compiler. The --disable-build-with-cxx configure option has been
365 * Building GDB and GDBserver now requires GNU make >= 3.81.
367 It is no longer supported to build GDB or GDBserver with another
368 implementation of the make program or an earlier version of GNU make.
370 * Native debugging on MS-Windows supports command-line redirection
372 Command-line arguments used for starting programs on MS-Windows can
373 now include redirection symbols supported by native Windows shells,
374 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
375 as "run", "start", and "set args", as well as the corresponding MI
378 * Support for thread names on MS-Windows.
380 GDB now catches and handles the special exception that programs
381 running on MS-Windows use to assign names to threads in the
384 * Support for Java programs compiled with gcj has been removed.
386 * User commands now accept an unlimited number of arguments.
387 Previously, only up to 10 was accepted.
389 * The "eval" command now expands user-defined command arguments.
391 This makes it easier to process a variable number of arguments:
396 eval "print $arg%d", $i
401 * Target descriptions can now describe registers for sparc32 and sparc64.
403 * GDB now supports DWARF version 5 (debug information format).
404 Its .debug_names index is not yet supported.
406 * New native configurations
408 FreeBSD/mips mips*-*-freebsd
412 Synopsys ARC arc*-*-elf32
413 FreeBSD/mips mips*-*-freebsd
415 * Removed targets and native configurations
417 Alpha running FreeBSD alpha*-*-freebsd*
418 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
423 Erases all the flash memory regions reported by the target.
425 maint print arc arc-instruction address
426 Print internal disassembler information about instruction at a given address.
430 set disassembler-options
431 show disassembler-options
432 Controls the passing of target specific information to the disassembler.
433 If it is necessary to specify more than one disassembler option then
434 multiple options can be placed together into a comma separated list.
435 The default value is the empty string. Currently, the only supported
436 targets are ARM, PowerPC and S/390.
441 Erases all the flash memory regions reported by the target. This is
442 equivalent to the CLI command flash-erase.
444 -file-list-shared-libraries
445 List the shared libraries in the program. This is
446 equivalent to the CLI command "info shared".
449 Catchpoints stopping the program when Ada exceptions are
450 handled. This is equivalent to the CLI command "catch handlers".
452 *** Changes in GDB 7.12
454 * GDB and GDBserver now build with a C++ compiler by default.
456 The --enable-build-with-cxx configure option is now enabled by
457 default. One must now explicitly configure with
458 --disable-build-with-cxx in order to build with a C compiler. This
459 option will be removed in a future release.
461 * GDBserver now supports recording btrace without maintaining an active
464 * GDB now supports a negative repeat count in the 'x' command to examine
465 memory backward from the given address. For example:
468 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
469 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
470 (gdb) x/-5i 0x0000000000400580
471 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
472 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
473 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
474 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
475 0x40057b <main(int, char**)+25>:
476 callq 0x400536 <Func1(int, char const*)>
478 * Fortran: Support structures with fields of dynamic types and
479 arrays of dynamic types.
481 * The symbol dumping maintenance commands have new syntax.
482 maint print symbols [-pc address] [--] [filename]
483 maint print symbols [-objfile objfile] [-source source] [--] [filename]
484 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
485 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
486 maint print msymbols [-objfile objfile] [--] [filename]
488 * GDB now supports multibit bitfields and enums in target register
491 * New Python-based convenience function $_as_string(val), which returns
492 the textual representation of a value. This function is especially
493 useful to obtain the text label of an enum value.
495 * Intel MPX bound violation handling.
497 Segmentation faults caused by a Intel MPX boundary violation
498 now display the kind of violation (upper or lower), the memory
499 address accessed and the memory bounds, along with the usual
500 signal received and code location.
504 Program received signal SIGSEGV, Segmentation fault
505 Upper bound violation while accessing address 0x7fffffffc3b3
506 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
507 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
509 * Rust language support.
510 GDB now supports debugging programs written in the Rust programming
511 language. See https://www.rust-lang.org/ for more information about
514 * Support for running interpreters on specified input/output devices
516 GDB now supports a new mechanism that allows frontends to provide
517 fully featured GDB console views, as a better alternative to
518 building such views on top of the "-interpreter-exec console"
519 command. See the new "new-ui" command below. With that command,
520 frontends can now start GDB in the traditional command-line mode
521 running in an embedded terminal emulator widget, and create a
522 separate MI interpreter running on a specified i/o device. In this
523 way, GDB handles line editing, history, tab completion, etc. in the
524 console all by itself, and the GUI uses the separate MI interpreter
525 for its own control and synchronization, invisible to the command
528 * The "catch syscall" command catches groups of related syscalls.
530 The "catch syscall" command now supports catching a group of related
531 syscalls using the 'group:' or 'g:' prefix.
536 skip -gfile file-glob-pattern
537 skip -function function
538 skip -rfunction regular-expression
539 A generalized form of the skip command, with new support for
540 glob-style file names and regular expressions for function names.
541 Additionally, a file spec and a function spec may now be combined.
543 maint info line-table REGEXP
544 Display the contents of GDB's internal line table data struture.
547 Run any GDB unit tests that were compiled in.
550 Start a new user interface instance running INTERP as interpreter,
551 using the TTY file for input/output.
555 ** gdb.Breakpoint objects have a new attribute "pending", which
556 indicates whether the breakpoint is pending.
557 ** Three new breakpoint-related events have been added:
558 gdb.breakpoint_created, gdb.breakpoint_modified, and
559 gdb.breakpoint_deleted.
562 Signal ("set") the given MS-Windows event object. This is used in
563 conjunction with the Windows JIT debugging (AeDebug) support, where
564 the OS suspends a crashing process until a debugger can attach to
565 it. Resuming the crashing process, in order to debug it, is done by
568 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
569 was added in GDBserver, including JIT compiling fast tracepoint's
570 conditional expression bytecode into native code.
572 * Support for various remote target protocols and ROM monitors has
575 target m32rsdi Remote M32R debugging over SDI
576 target mips MIPS remote debugging protocol
577 target pmon PMON ROM monitor
578 target ddb NEC's DDB variant of PMON for Vr4300
579 target rockhopper NEC RockHopper variant of PMON
580 target lsi LSI variant of PMO
582 * Support for tracepoints and fast tracepoints on powerpc-linux,
583 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
584 including JIT compiling fast tracepoint's conditional expression
585 bytecode into native code.
587 * MI async record =record-started now includes the method and format used for
588 recording. For example:
590 =record-started,thread-group="i1",method="btrace",format="bts"
592 * MI async record =thread-selected now includes the frame field. For example:
594 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
598 Andes NDS32 nds32*-*-elf
600 *** Changes in GDB 7.11
602 * GDB now supports debugging kernel-based threads on FreeBSD.
604 * Per-inferior thread numbers
606 Thread numbers are now per inferior instead of global. If you're
607 debugging multiple inferiors, GDB displays thread IDs using a
608 qualified INF_NUM.THR_NUM form. For example:
612 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
613 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
614 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
615 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
617 As consequence, thread numbers as visible in the $_thread
618 convenience variable and in Python's InferiorThread.num attribute
619 are no longer unique between inferiors.
621 GDB now maintains a second thread ID per thread, referred to as the
622 global thread ID, which is the new equivalent of thread numbers in
623 previous releases. See also $_gthread below.
625 For backwards compatibility, MI's thread IDs always refer to global
628 * Commands that accept thread IDs now accept the qualified
629 INF_NUM.THR_NUM form as well. For example:
632 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
635 * In commands that accept a list of thread IDs, you can now refer to
636 all threads of an inferior using a star wildcard. GDB accepts
637 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
638 refer to all threads of the current inferior. For example, "info
641 * You can use "info threads -gid" to display the global thread ID of
644 * The new convenience variable $_gthread holds the global number of
647 * The new convenience variable $_inferior holds the number of the
650 * GDB now displays the ID and name of the thread that hit a breakpoint
651 or received a signal, if your program is multi-threaded. For
654 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
655 Thread 1 "main" received signal SIGINT, Interrupt.
657 * Record btrace now supports non-stop mode.
659 * Support for tracepoints on aarch64-linux was added in GDBserver.
661 * The 'record instruction-history' command now indicates speculative execution
662 when using the Intel Processor Trace recording format.
664 * GDB now allows users to specify explicit locations, bypassing
665 the linespec parser. This feature is also available to GDB/MI
668 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
669 GDB now is able to debug both AArch64 applications and ARM applications
672 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
673 including JIT compiling fast tracepoint's conditional expression bytecode
676 * GDB now supports displaced stepping on AArch64 GNU/Linux.
678 * "info threads", "info inferiors", "info display", "info checkpoints"
679 and "maint info program-spaces" now list the corresponding items in
680 ascending ID order, for consistency with all other "info" commands.
682 * In Ada, the overloads selection menu has been enhanced to display the
683 parameter types and the return types for the matching overloaded subprograms.
687 maint set target-non-stop (on|off|auto)
688 maint show target-non-stop
689 Control whether GDB targets always operate in non-stop mode even if
690 "set non-stop" is "off". The default is "auto", meaning non-stop
691 mode is enabled if supported by the target.
693 maint set bfd-sharing
694 maint show bfd-sharing
695 Control the reuse of bfd objects.
699 Control display of debugging info regarding bfd caching.
703 Control display of debugging info regarding FreeBSD threads.
705 set remote multiprocess-extensions-packet
706 show remote multiprocess-extensions-packet
707 Set/show the use of the remote protocol multiprocess extensions.
709 set remote thread-events
710 show remote thread-events
711 Set/show the use of thread create/exit events.
713 set ada print-signatures on|off
714 show ada print-signatures"
715 Control whether parameter types and return types are displayed in overloads
716 selection menus. It is activaled (@code{on}) by default.
720 Controls the maximum size of memory, in bytes, that GDB will
721 allocate for value contents. Prevents incorrect programs from
722 causing GDB to allocate overly large buffers. Default is 64k.
724 * The "disassemble" command accepts a new modifier: /s.
725 It prints mixed source+disassembly like /m with two differences:
726 - disassembled instructions are now printed in program order, and
727 - and source for all relevant files is now printed.
728 The "/m" option is now considered deprecated: its "source-centric"
729 output hasn't proved useful in practice.
731 * The "record instruction-history" command accepts a new modifier: /s.
732 It behaves exactly like /m and prints mixed source+disassembly.
734 * The "set scheduler-locking" command supports a new mode "replay".
735 It behaves like "off" in record mode and like "on" in replay mode.
737 * Support for various ROM monitors has been removed:
739 target dbug dBUG ROM monitor for Motorola ColdFire
740 target picobug Motorola picobug monitor
741 target dink32 DINK32 ROM monitor for PowerPC
742 target m32r Renesas M32R/D ROM monitor
743 target mon2000 mon2000 ROM monitor
744 target ppcbug PPCBUG ROM monitor for PowerPC
746 * Support for reading/writing memory and extracting values on architectures
747 whose memory is addressable in units of any integral multiple of 8 bits.
750 Allows to break when an Ada exception is handled.
755 Indicates that an exec system call was executed.
757 exec-events feature in qSupported
758 The qSupported packet allows GDB to request support for exec
759 events using the new 'gdbfeature' exec-event, and the qSupported
760 response can contain the corresponding 'stubfeature'. Set and
761 show commands can be used to display whether these features are enabled.
764 Equivalent to interrupting with the ^C character, but works in
767 thread created stop reason (T05 create:...)
768 Indicates that the thread was just created and is stopped at entry.
770 thread exit stop reply (w exitcode;tid)
771 Indicates that the thread has terminated.
774 Enables/disables thread create and exit event reporting. For
775 example, this is used in non-stop mode when GDB stops a set of
776 threads and synchronously waits for the their corresponding stop
777 replies. Without exit events, if one of the threads exits, GDB
778 would hang forever not knowing that it should no longer expect a
779 stop for that same thread.
782 Indicates that there are no resumed threads left in the target (all
783 threads are stopped). The remote stub reports support for this stop
784 reply to GDB's qSupported query.
787 Enables/disables catching syscalls from the inferior process.
788 The remote stub reports support for this packet to GDB's qSupported query.
790 syscall_entry stop reason
791 Indicates that a syscall was just called.
793 syscall_return stop reason
794 Indicates that a syscall just returned.
796 * Extended-remote exec events
798 ** GDB now has support for exec events on extended-remote Linux targets.
799 For such targets with Linux kernels 2.5.46 and later, this enables
800 follow-exec-mode and exec catchpoints.
802 set remote exec-event-feature-packet
803 show remote exec-event-feature-packet
804 Set/show the use of the remote exec event feature.
806 * Thread names in remote protocol
808 The reply to qXfer:threads:read may now include a name attribute for each
811 * Target remote mode fork and exec events
813 ** GDB now has support for fork and exec events on target remote mode
814 Linux targets. For such targets with Linux kernels 2.5.46 and later,
815 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
816 fork and exec catchpoints.
818 * Remote syscall events
820 ** GDB now has support for catch syscall on remote Linux targets,
821 currently enabled on x86/x86_64 architectures.
823 set remote catch-syscall-packet
824 show remote catch-syscall-packet
825 Set/show the use of the remote catch syscall feature.
829 ** The -var-set-format command now accepts the zero-hexadecimal
830 format. It outputs data in hexadecimal format with zero-padding on the
835 ** gdb.InferiorThread objects have a new attribute "global_num",
836 which refers to the thread's global thread ID. The existing
837 "num" attribute now refers to the thread's per-inferior number.
838 See "Per-inferior thread numbers" above.
839 ** gdb.InferiorThread objects have a new attribute "inferior", which
840 is the Inferior object the thread belongs to.
842 *** Changes in GDB 7.10
844 * Support for process record-replay and reverse debugging on aarch64*-linux*
845 targets has been added. GDB now supports recording of A64 instruction set
846 including advance SIMD instructions.
848 * Support for Sun's version of the "stabs" debug file format has been removed.
850 * GDB now honors the content of the file /proc/PID/coredump_filter
851 (PID is the process ID) on GNU/Linux systems. This file can be used
852 to specify the types of memory mappings that will be included in a
853 corefile. For more information, please refer to the manual page of
854 "core(5)". GDB also has a new command: "set use-coredump-filter
855 on|off". It allows to set whether GDB will read the content of the
856 /proc/PID/coredump_filter file when generating a corefile.
858 * The "info os" command on GNU/Linux can now display information on
860 "info os cpus" Listing of all cpus/cores on the system
862 * GDB has two new commands: "set serial parity odd|even|none" and
863 "show serial parity". These allows to set or show parity for the
866 * The "info source" command now displays the producer string if it was
867 present in the debug info. This typically includes the compiler version
868 and may include things like its command line arguments.
870 * The "info dll", an alias of the "info sharedlibrary" command,
871 is now available on all platforms.
873 * Directory names supplied to the "set sysroot" commands may be
874 prefixed with "target:" to tell GDB to access shared libraries from
875 the target system, be it local or remote. This replaces the prefix
876 "remote:". The default sysroot has been changed from "" to
877 "target:". "remote:" is automatically converted to "target:" for
878 backward compatibility.
880 * The system root specified by "set sysroot" will be prepended to the
881 filename of the main executable (if reported to GDB as absolute by
882 the operating system) when starting processes remotely, and when
883 attaching to already-running local or remote processes.
885 * GDB now supports automatic location and retrieval of executable
886 files from remote targets. Remote debugging can now be initiated
887 using only a "target remote" or "target extended-remote" command
888 (no "set sysroot" or "file" commands are required). See "New remote
891 * The "dump" command now supports verilog hex format.
893 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
895 * On GNU/Linux, GDB and gdbserver are now able to access executable
896 and shared library files without a "set sysroot" command when
897 attaching to processes running in different mount namespaces from
898 the debugger. This makes it possible to attach to processes in
899 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
900 See "New remote packets" below.
902 * The "tui reg" command now provides completion for all of the
903 available register groups, including target specific groups.
905 * The HISTSIZE environment variable is no longer read when determining
906 the size of GDB's command history. GDB now instead reads the dedicated
907 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
908 disables truncation of command history. Non-numeric values of GDBHISTSIZE
913 ** Memory ports can now be unbuffered.
917 ** gdb.Objfile objects have a new attribute "username",
918 which is the name of the objfile as specified by the user,
919 without, for example, resolving symlinks.
920 ** You can now write frame unwinders in Python.
921 ** gdb.Type objects have a new method "optimized_out",
922 returning optimized out gdb.Value instance of this type.
923 ** gdb.Value objects have new methods "reference_value" and
924 "const_value" which return a reference to the value and a
925 "const" version of the value respectively.
929 maint print symbol-cache
930 Print the contents of the symbol cache.
932 maint print symbol-cache-statistics
933 Print statistics of symbol cache usage.
935 maint flush-symbol-cache
936 Flush the contents of the symbol cache.
940 Start branch trace recording using Branch Trace Store (BTS) format.
943 Evaluate expression by using the compiler and print result.
947 Explicit commands for enabling and disabling tui mode.
950 set mpx bound on i386 and amd64
951 Support for bound table investigation on Intel MPX enabled applications.
955 Start branch trace recording using Intel Processor Trace format.
958 Print information about branch tracing internals.
960 maint btrace packet-history
961 Print the raw branch tracing data.
963 maint btrace clear-packet-history
964 Discard the stored raw branch tracing data.
967 Discard all branch tracing data. It will be fetched and processed
968 anew by the next "record" command.
973 Renamed from "set debug dwarf2-die".
975 Renamed from "show debug dwarf2-die".
978 Renamed from "set debug dwarf2-read".
979 show debug dwarf-read
980 Renamed from "show debug dwarf2-read".
982 maint set dwarf always-disassemble
983 Renamed from "maint set dwarf2 always-disassemble".
984 maint show dwarf always-disassemble
985 Renamed from "maint show dwarf2 always-disassemble".
987 maint set dwarf max-cache-age
988 Renamed from "maint set dwarf2 max-cache-age".
989 maint show dwarf max-cache-age
990 Renamed from "maint show dwarf2 max-cache-age".
993 show debug dwarf-line
994 Control display of debugging info regarding DWARF line processing.
998 Set the maximum number of candidates to be considered during
999 completion. The default value is 200. This limit allows GDB
1000 to avoid generating large completion lists, the computation of
1001 which can cause the debugger to become temporarily unresponsive.
1003 set history remove-duplicates
1004 show history remove-duplicates
1005 Control the removal of duplicate history entries.
1007 maint set symbol-cache-size
1008 maint show symbol-cache-size
1009 Control the size of the symbol cache.
1011 set|show record btrace bts buffer-size
1012 Set and show the size of the ring buffer used for branch tracing in
1014 The obtained size may differ from the requested size. Use "info
1015 record" to see the obtained buffer size.
1017 set debug linux-namespaces
1018 show debug linux-namespaces
1019 Control display of debugging info regarding Linux namespaces.
1021 set|show record btrace pt buffer-size
1022 Set and show the size of the ring buffer used for branch tracing in
1023 Intel Processor Trace format.
1024 The obtained size may differ from the requested size. Use "info
1025 record" to see the obtained buffer size.
1027 maint set|show btrace pt skip-pad
1028 Set and show whether PAD packets are skipped when computing the
1031 * The command 'thread apply all' can now support new option '-ascending'
1032 to call its specified command for all threads in ascending order.
1034 * Python/Guile scripting
1036 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1037 special section named `.debug_gdb_scripts'.
1039 * New remote packets
1041 qXfer:btrace-conf:read
1042 Return the branch trace configuration for the current thread.
1044 Qbtrace-conf:bts:size
1045 Set the requested ring buffer size for branch tracing in BTS format.
1048 Enable Intel Procesor Trace-based branch tracing for the current
1049 process. The remote stub reports support for this packet to GDB's
1052 Qbtrace-conf:pt:size
1053 Set the requested ring buffer size for branch tracing in Intel Processor
1057 Indicates a memory breakpoint instruction was executed, irrespective
1058 of whether it was GDB that planted the breakpoint or the breakpoint
1059 is hardcoded in the program. This is required for correct non-stop
1063 Indicates the target stopped for a hardware breakpoint. This is
1064 required for correct non-stop mode operation.
1067 Return information about files on the remote system.
1069 qXfer:exec-file:read
1070 Return the full absolute name of the file that was executed to
1071 create a process running on the remote system.
1074 Select the filesystem on which vFile: operations with filename
1075 arguments will operate. This is required for GDB to be able to
1076 access files on remote targets where the remote stub does not
1077 share a common filesystem with the inferior(s).
1080 Indicates that a fork system call was executed.
1083 Indicates that a vfork system call was executed.
1085 vforkdone stop reason
1086 Indicates that a vfork child of the specified process has executed
1087 an exec or exit, allowing the vfork parent to resume execution.
1089 fork-events and vfork-events features in qSupported
1090 The qSupported packet allows GDB to request support for fork and
1091 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1092 and the qSupported response can contain the corresponding
1093 'stubfeatures'. Set and show commands can be used to display
1094 whether these features are enabled.
1096 * Extended-remote fork events
1098 ** GDB now has support for fork events on extended-remote Linux
1099 targets. For targets with Linux kernels 2.5.60 and later, this
1100 enables follow-fork-mode and detach-on-fork for both fork and
1101 vfork, as well as fork and vfork catchpoints.
1103 * The info record command now shows the recording format and the
1104 branch tracing configuration for the current thread when using
1105 the btrace record target.
1106 For the BTS format, it shows the ring buffer size.
1108 * GDB now has support for DTrace USDT (Userland Static Defined
1109 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1111 * GDB now supports access to vector registers on S/390 GNU/Linux
1114 * Removed command line options
1116 -xdb HP-UX XDB compatibility mode.
1118 * Removed targets and native configurations
1120 HP/PA running HP-UX hppa*-*-hpux*
1121 Itanium running HP-UX ia64-*-hpux*
1123 * New configure options
1126 This configure option allows the user to build GDB with support for
1127 Intel Processor Trace (default: auto). This requires libipt.
1129 --with-libipt-prefix=PATH
1130 Specify the path to the version of libipt that GDB should use.
1131 $PATH/include should contain the intel-pt.h header and
1132 $PATH/lib should contain the libipt.so library.
1134 *** Changes in GDB 7.9.1
1138 ** Xmethods can now specify a result type.
1140 *** Changes in GDB 7.9
1142 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1146 ** You can now access frame registers from Python scripts.
1147 ** New attribute 'producer' for gdb.Symtab objects.
1148 ** gdb.Objfile objects have a new attribute "progspace",
1149 which is the gdb.Progspace object of the containing program space.
1150 ** gdb.Objfile objects have a new attribute "owner".
1151 ** gdb.Objfile objects have a new attribute "build_id",
1152 which is the build ID generated when the file was built.
1153 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1154 ** A new event "gdb.clear_objfiles" has been added, triggered when
1155 selecting a new file to debug.
1156 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1157 ** New function gdb.lookup_objfile.
1159 New events which are triggered when GDB modifies the state of the
1162 ** gdb.events.inferior_call_pre: Function call is about to be made.
1163 ** gdb.events.inferior_call_post: Function call has just been made.
1164 ** gdb.events.memory_changed: A memory location has been altered.
1165 ** gdb.events.register_changed: A register has been altered.
1167 * New Python-based convenience functions:
1169 ** $_caller_is(name [, number_of_frames])
1170 ** $_caller_matches(regexp [, number_of_frames])
1171 ** $_any_caller_is(name [, number_of_frames])
1172 ** $_any_caller_matches(regexp [, number_of_frames])
1174 * GDB now supports the compilation and injection of source code into
1175 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1176 to compile the source code to object code, and if successful, inject
1177 and execute that code within the current context of the inferior.
1178 Currently the C language is supported. The commands used to
1179 interface with this new feature are:
1181 compile code [-raw|-r] [--] [source code]
1182 compile file [-raw|-r] filename
1186 demangle [-l language] [--] name
1187 Demangle "name" in the specified language, or the current language
1188 if elided. This command is renamed from the "maint demangle" command.
1189 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1190 as "maint demangler-warning".
1192 queue-signal signal-name-or-number
1193 Queue a signal to be delivered to the thread when it is resumed.
1195 add-auto-load-scripts-directory directory
1196 Add entries to the list of directories from which to load auto-loaded
1199 maint print user-registers
1200 List all currently available "user" registers.
1202 compile code [-r|-raw] [--] [source code]
1203 Compile, inject, and execute in the inferior the executable object
1204 code produced by compiling the provided source code.
1206 compile file [-r|-raw] filename
1207 Compile and inject into the inferior the executable object code
1208 produced by compiling the source code stored in the filename
1211 * On resume, GDB now always passes the signal the program had stopped
1212 for to the thread the signal was sent to, even if the user changed
1213 threads before resuming. Previously GDB would often (but not
1214 always) deliver the signal to the thread that happens to be current
1217 * Conversely, the "signal" command now consistently delivers the
1218 requested signal to the current thread. GDB now asks for
1219 confirmation if the program had stopped for a signal and the user
1220 switched threads meanwhile.
1222 * "breakpoint always-inserted" modes "off" and "auto" merged.
1224 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1225 won't remove breakpoints from the target until all threads stop,
1226 even in non-stop mode. The "auto" mode has been removed, and "off"
1227 is now the default mode.
1231 set debug symbol-lookup
1232 show debug symbol-lookup
1233 Control display of debugging info regarding symbol lookup.
1237 ** The -list-thread-groups command outputs an exit-code field for
1238 inferiors that have exited.
1242 MIPS SDE mips*-sde*-elf*
1246 Support for these obsolete configurations has been removed.
1248 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1249 SGI Irix-5.x mips-*-irix5*
1250 SGI Irix-6.x mips-*-irix6*
1251 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1252 VAX running Ultrix vax-*-ultrix*
1254 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1255 and "assf"), have been removed. Use the "sharedlibrary" command, or
1256 its alias "share", instead.
1258 *** Changes in GDB 7.8
1260 * New command line options
1263 This is an alias for the --data-directory option.
1265 * GDB supports printing and modifying of variable length automatic arrays
1266 as specified in ISO C99.
1268 * The ARM simulator now supports instruction level tracing
1269 with or without disassembly.
1273 GDB now has support for scripting using Guile. Whether this is
1274 available is determined at configure time.
1275 Guile version 2.0 or greater is required.
1276 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1278 * New commands (for set/show, see "New options" below)
1282 Invoke CODE by passing it to the Guile interpreter.
1286 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1288 info auto-load guile-scripts [regexp]
1289 Print the list of automatically loaded Guile scripts.
1291 * The source command is now capable of sourcing Guile scripts.
1292 This feature is dependent on the debugger being built with Guile support.
1296 set print symbol-loading (off|brief|full)
1297 show print symbol-loading
1298 Control whether to print informational messages when loading symbol
1299 information for a file. The default is "full", but when debugging
1300 programs with large numbers of shared libraries the amount of output
1301 becomes less useful.
1303 set guile print-stack (none|message|full)
1304 show guile print-stack
1305 Show a stack trace when an error is encountered in a Guile script.
1307 set auto-load guile-scripts (on|off)
1308 show auto-load guile-scripts
1309 Control auto-loading of Guile script files.
1311 maint ada set ignore-descriptive-types (on|off)
1312 maint ada show ignore-descriptive-types
1313 Control whether the debugger should ignore descriptive types in Ada
1314 programs. The default is not to ignore the descriptive types. See
1315 the user manual for more details on descriptive types and the intended
1316 usage of this option.
1318 set auto-connect-native-target
1320 Control whether GDB is allowed to automatically connect to the
1321 native target for the run, attach, etc. commands when not connected
1322 to any target yet. See also "target native" below.
1324 set record btrace replay-memory-access (read-only|read-write)
1325 show record btrace replay-memory-access
1326 Control what memory accesses are allowed during replay.
1328 maint set target-async (on|off)
1329 maint show target-async
1330 This controls whether GDB targets operate in synchronous or
1331 asynchronous mode. Normally the default is asynchronous, if it is
1332 available; but this can be changed to more easily debug problems
1333 occurring only in synchronous mode.
1335 set mi-async (on|off)
1337 Control whether MI asynchronous mode is preferred. This supersedes
1338 "set target-async" of previous GDB versions.
1340 * "set target-async" is deprecated as a CLI option and is now an alias
1341 for "set mi-async" (only puts MI into async mode).
1343 * Background execution commands (e.g., "c&", "s&", etc.) are now
1344 possible ``out of the box'' if the target supports them. Previously
1345 the user would need to explicitly enable the possibility with the
1346 "set target-async on" command.
1348 * New features in the GDB remote stub, GDBserver
1350 ** New option --debug-format=option1[,option2,...] allows one to add
1351 additional text to each output. At present only timestamps
1352 are supported: --debug-format=timestamps.
1353 Timestamps can also be turned on with the
1354 "monitor set debug-format timestamps" command from GDB.
1356 * The 'record instruction-history' command now starts counting instructions
1357 at one. This also affects the instruction ranges reported by the
1358 'record function-call-history' command when given the /i modifier.
1360 * The command 'record function-call-history' supports a new modifier '/c' to
1361 indent the function names based on their call stack depth.
1362 The fields for the '/i' and '/l' modifier have been reordered.
1363 The source line range is now prefixed with 'at'.
1364 The instruction range is now prefixed with 'inst'.
1365 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1366 "record instruction-history" and "list" commands.
1368 * The ranges given as arguments to the 'record function-call-history' and
1369 'record instruction-history' commands are now inclusive.
1371 * The btrace record target now supports the 'record goto' command.
1372 For locations inside the execution trace, the back trace is computed
1373 based on the information stored in the execution trace.
1375 * The btrace record target supports limited reverse execution and replay.
1376 The target does not record data and therefore does not allow reading
1377 memory or registers.
1379 * The "catch syscall" command now works on s390*-linux* targets.
1381 * The "compare-sections" command is no longer specific to target
1382 remote. It now works with all targets.
1384 * All native targets are now consistently called "native".
1385 Consequently, the "target child", "target GNU", "target djgpp",
1386 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1387 commands have been replaced with "target native". The QNX/NTO port
1388 leaves the "procfs" target in place and adds a "native" target for
1389 consistency with other ports. The impact on users should be minimal
1390 as these commands previously either throwed an error, or were
1391 no-ops. The target's name is visible in the output of the following
1392 commands: "help target", "info target", "info files", "maint print
1395 * The "target native" command now connects to the native target. This
1396 can be used to launch native programs even when "set
1397 auto-connect-native-target" is set to off.
1399 * GDB now supports access to Intel MPX registers on GNU/Linux.
1401 * Support for Intel AVX-512 registers on GNU/Linux.
1402 Support displaying and modifying Intel AVX-512 registers
1403 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1405 * New remote packets
1407 qXfer:btrace:read's annex
1408 The qXfer:btrace:read packet supports a new annex 'delta' to read
1409 branch trace incrementally.
1413 ** Valid Python operations on gdb.Value objects representing
1414 structs/classes invoke the corresponding overloaded operators if
1416 ** New `Xmethods' feature in the Python API. Xmethods are
1417 additional methods or replacements for existing methods of a C++
1418 class. This feature is useful for those cases where a method
1419 defined in C++ source code could be inlined or optimized out by
1420 the compiler, making it unavailable to GDB.
1423 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1425 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1426 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1427 its alias "share", instead.
1429 * The commands "set remotebaud" and "show remotebaud" are no longer
1430 supported. Use "set serial baud" and "show serial baud" (respectively)
1435 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1436 target-async". The latter is left as a deprecated alias of the
1437 former for backward compatibility. If the target supports it,
1438 CLI background execution commands are now always possible by
1439 default, independently of whether the frontend stated a
1440 preference for asynchronous execution with "-gdb-set mi-async".
1441 Previously "-gdb-set target-async off" affected both MI execution
1442 commands and CLI execution commands.
1444 *** Changes in GDB 7.7
1446 * Improved support for process record-replay and reverse debugging on
1447 arm*-linux* targets. Support for thumb32 and syscall instruction
1448 recording has been added.
1450 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1452 * GDB now supports Fission DWP file format version 2.
1453 http://gcc.gnu.org/wiki/DebugFission
1455 * New convenience function "$_isvoid", to check whether an expression
1456 is void. A void expression is an expression where the type of the
1457 result is "void". For example, some convenience variables may be
1458 "void" when evaluated (e.g., "$_exitcode" before the execution of
1459 the program being debugged; or an undefined convenience variable).
1460 Another example, when calling a function whose return type is
1463 * The "maintenance print objfiles" command now takes an optional regexp.
1465 * The "catch syscall" command now works on arm*-linux* targets.
1467 * GDB now consistently shows "<not saved>" when printing values of
1468 registers the debug info indicates have not been saved in the frame
1469 and there's nowhere to retrieve them from
1470 (callee-saved/call-clobbered registers):
1475 (gdb) info registers rax
1478 Before, the former would print "<optimized out>", and the latter
1479 "*value not available*".
1481 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1486 ** Frame filters and frame decorators have been added.
1487 ** Temporary breakpoints are now supported.
1488 ** Line tables representation has been added.
1489 ** New attribute 'parent_type' for gdb.Field objects.
1490 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1491 ** New attribute 'name' for gdb.Type objects.
1495 Nios II ELF nios2*-*-elf
1496 Nios II GNU/Linux nios2*-*-linux
1497 Texas Instruments MSP430 msp430*-*-elf
1499 * Removed native configurations
1501 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1502 been removed. ELF variants of these configurations are kept supported.
1504 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1505 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1506 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1507 i[34567]86-*-openbsd3.[0-3]
1508 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1509 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1510 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1514 Like "catch throw", but catches a re-thrown exception.
1515 maint check-psymtabs
1516 Renamed from old "maint check-symtabs".
1518 Perform consistency checks on symtabs.
1519 maint expand-symtabs
1520 Expand symtabs matching an optional regexp.
1523 Display the details of GDB configure-time options.
1525 maint set|show per-command
1526 maint set|show per-command space
1527 maint set|show per-command time
1528 maint set|show per-command symtab
1529 Enable display of per-command gdb resource usage.
1531 remove-symbol-file FILENAME
1532 remove-symbol-file -a ADDRESS
1533 Remove a symbol file added via add-symbol-file. The file to remove
1534 can be identified by its filename or by an address that lies within
1535 the boundaries of this symbol file in memory.
1538 info exceptions REGEXP
1539 Display the list of Ada exceptions defined in the program being
1540 debugged. If provided, only the exceptions whose names match REGEXP
1545 set debug symfile off|on
1547 Control display of debugging info regarding reading symbol files and
1548 symbol tables within those files
1550 set print raw frame-arguments
1551 show print raw frame-arguments
1552 Set/show whether to print frame arguments in raw mode,
1553 disregarding any defined pretty-printers.
1555 set remote trace-status-packet
1556 show remote trace-status-packet
1557 Set/show the use of remote protocol qTStatus packet.
1561 Control display of debugging messages related to Nios II targets.
1565 Control whether target-assisted range stepping is enabled.
1567 set startup-with-shell
1568 show startup-with-shell
1569 Specifies whether Unix child processes are started via a shell or
1574 Use the target memory cache for accesses to the code segment. This
1575 improves performance of remote debugging (particularly disassembly).
1577 * You can now use a literal value 'unlimited' for options that
1578 interpret 0 or -1 as meaning "unlimited". E.g., "set
1579 trace-buffer-size unlimited" is now an alias for "set
1580 trace-buffer-size -1" and "set height unlimited" is now an alias for
1583 * The "set debug symtab-create" debugging option of GDB has been changed to
1584 accept a verbosity level. 0 means "off", 1 provides basic debugging
1585 output, and values of 2 or greater provides more verbose output.
1587 * New command-line options
1589 Display the details of GDB configure-time options.
1591 * The command 'tsave' can now support new option '-ctf' to save trace
1592 buffer in Common Trace Format.
1594 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1597 * GDB now implements the the C++ 'typeid' operator.
1599 * The new convenience variable $_exception holds the exception being
1600 thrown or caught at an exception-related catchpoint.
1602 * The exception-related catchpoints, like "catch throw", now accept a
1603 regular expression which can be used to filter exceptions by type.
1605 * The new convenience variable $_exitsignal is automatically set to
1606 the terminating signal number when the program being debugged dies
1607 due to an uncaught signal.
1611 ** All MI commands now accept an optional "--language" option.
1612 Support for this feature can be verified by using the "-list-features"
1613 command, which should contain "language-option".
1615 ** The new command -info-gdb-mi-command allows the user to determine
1616 whether a GDB/MI command is supported or not.
1618 ** The "^error" result record returned when trying to execute an undefined
1619 GDB/MI command now provides a variable named "code" whose content is the
1620 "undefined-command" error code. Support for this feature can be verified
1621 by using the "-list-features" command, which should contain
1622 "undefined-command-error-code".
1624 ** The -trace-save MI command can optionally save trace buffer in Common
1627 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1629 ** The command -data-list-register-values now accepts an optional
1630 "--skip-unavailable" option. When used, only the available registers
1633 ** The new command -trace-frame-collected dumps collected variables,
1634 computed expressions, tvars, memory and registers in a traceframe.
1636 ** The commands -stack-list-locals, -stack-list-arguments and
1637 -stack-list-variables now accept an option "--skip-unavailable".
1638 When used, only the available locals or arguments are displayed.
1640 ** The -exec-run command now accepts an optional "--start" option.
1641 When used, the command follows the same semantics as the "start"
1642 command, stopping the program's execution at the start of its
1643 main subprogram. Support for this feature can be verified using
1644 the "-list-features" command, which should contain
1645 "exec-run-start-option".
1647 ** The new commands -catch-assert and -catch-exceptions insert
1648 catchpoints stopping the program when Ada exceptions are raised.
1650 ** The new command -info-ada-exceptions provides the equivalent of
1651 the new "info exceptions" command.
1653 * New system-wide configuration scripts
1654 A GDB installation now provides scripts suitable for use as system-wide
1655 configuration scripts for the following systems:
1659 * GDB now supports target-assigned range stepping with remote targets.
1660 This improves the performance of stepping source lines by reducing
1661 the number of control packets from/to GDB. See "New remote packets"
1664 * GDB now understands the element 'tvar' in the XML traceframe info.
1665 It has the id of the collected trace state variables.
1667 * On S/390 targets that provide the transactional-execution feature,
1668 the program interruption transaction diagnostic block (TDB) is now
1669 represented as a number of additional "registers" in GDB.
1671 * New remote packets
1675 The vCont packet supports a new 'r' action, that tells the remote
1676 stub to step through an address range itself, without GDB
1677 involvemement at each single-step.
1679 qXfer:libraries-svr4:read's annex
1680 The previously unused annex of the qXfer:libraries-svr4:read packet
1681 is now used to support passing an argument list. The remote stub
1682 reports support for this argument list to GDB's qSupported query.
1683 The defined arguments are "start" and "prev", used to reduce work
1684 necessary for library list updating, resulting in significant
1687 * New features in the GDB remote stub, GDBserver
1689 ** GDBserver now supports target-assisted range stepping. Currently
1690 enabled on x86/x86_64 GNU/Linux targets.
1692 ** GDBserver now adds element 'tvar' in the XML in the reply to
1693 'qXfer:traceframe-info:read'. It has the id of the collected
1694 trace state variables.
1696 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1699 * New 'z' formatter for printing and examining memory, this displays the
1700 value as hexadecimal zero padded on the left to the size of the type.
1702 * GDB can now use Windows x64 unwinding data.
1704 * The "set remotebaud" command has been replaced by "set serial baud".
1705 Similarly, "show remotebaud" has been replaced by "show serial baud".
1706 The "set remotebaud" and "show remotebaud" commands are still available
1707 to provide backward compatibility with older versions of GDB.
1709 *** Changes in GDB 7.6
1711 * Target record has been renamed to record-full.
1712 Record/replay is now enabled with the "record full" command.
1713 This also affects settings that are associated with full record/replay
1714 that have been moved from "set/show record" to "set/show record full":
1716 set|show record full insn-number-max
1717 set|show record full stop-at-limit
1718 set|show record full memory-query
1720 * A new record target "record-btrace" has been added. The new target
1721 uses hardware support to record the control-flow of a process. It
1722 does not support replaying the execution, but it implements the
1723 below new commands for investigating the recorded execution log.
1724 This new recording method can be enabled using:
1728 The "record-btrace" target is only available on Intel Atom processors
1729 and requires a Linux kernel 2.6.32 or later.
1731 * Two new commands have been added for record/replay to give information
1732 about the recorded execution without having to replay the execution.
1733 The commands are only supported by "record btrace".
1735 record instruction-history prints the execution history at
1736 instruction granularity
1738 record function-call-history prints the execution history at
1739 function granularity
1741 * New native configurations
1743 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1744 FreeBSD/powerpc powerpc*-*-freebsd
1745 x86_64/Cygwin x86_64-*-cygwin*
1746 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1750 ARM AArch64 aarch64*-*-elf
1751 ARM AArch64 GNU/Linux aarch64*-*-linux
1752 Lynx 178 PowerPC powerpc-*-lynx*178
1753 x86_64/Cygwin x86_64-*-cygwin*
1754 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1756 * If the configured location of system.gdbinit file (as given by the
1757 --with-system-gdbinit option at configure time) is in the
1758 data-directory (as specified by --with-gdb-datadir at configure
1759 time) or in one of its subdirectories, then GDB will look for the
1760 system-wide init file in the directory specified by the
1761 --data-directory command-line option.
1763 * New command line options:
1765 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1766 other initialization files, unlike -nx which disables all of them.
1768 * Removed command line options
1770 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1773 * The 'ptype' and 'whatis' commands now accept an argument to control
1776 * 'info proc' now works on some core files.
1780 ** Vectors can be created with gdb.Type.vector.
1782 ** Python's atexit.register now works in GDB.
1784 ** Types can be pretty-printed via a Python API.
1786 ** Python 3 is now supported (in addition to Python 2.4 or later)
1788 ** New class gdb.Architecture exposes GDB's internal representation
1789 of architecture in the Python API.
1791 ** New method Frame.architecture returns the gdb.Architecture object
1792 corresponding to the frame's architecture.
1794 * New Python-based convenience functions:
1796 ** $_memeq(buf1, buf2, length)
1797 ** $_streq(str1, str2)
1799 ** $_regex(str, regex)
1801 * The 'cd' command now defaults to using '~' (the home directory) if not
1804 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1805 default for GCC since November 2000.
1807 * The command 'forward-search' can now be abbreviated as 'fo'.
1809 * The command 'info tracepoints' can now display 'installed on target'
1810 or 'not installed on target' for each non-pending location of tracepoint.
1812 * New configure options
1814 --enable-libmcheck/--disable-libmcheck
1815 By default, development versions are built with -lmcheck on hosts
1816 that support it, in order to help track memory corruption issues.
1817 Release versions, on the other hand, are built without -lmcheck
1818 by default. The --enable-libmcheck/--disable-libmcheck configure
1819 options allow the user to override that default.
1820 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1821 This configure option allows the user to build GDB with
1822 libbabeltrace using which GDB can read Common Trace Format data.
1824 * New commands (for set/show, see "New options" below)
1827 Catch signals. This is similar to "handle", but allows commands and
1828 conditions to be attached.
1831 List the BFDs known to GDB.
1833 python-interactive [command]
1835 Start a Python interactive prompt, or evaluate the optional command
1836 and print the result of expressions.
1839 "py" is a new alias for "python".
1841 enable type-printer [name]...
1842 disable type-printer [name]...
1843 Enable or disable type printers.
1847 ** For the Renesas Super-H architecture, the "regs" command has been removed
1848 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1853 set print type methods (on|off)
1854 show print type methods
1855 Control whether method declarations are displayed by "ptype".
1856 The default is to show them.
1858 set print type typedefs (on|off)
1859 show print type typedefs
1860 Control whether typedef definitions are displayed by "ptype".
1861 The default is to show them.
1863 set filename-display basename|relative|absolute
1864 show filename-display
1865 Control the way in which filenames is displayed.
1866 The default is "relative", which preserves previous behavior.
1868 set trace-buffer-size
1869 show trace-buffer-size
1870 Request target to change the size of trace buffer.
1872 set remote trace-buffer-size-packet auto|on|off
1873 show remote trace-buffer-size-packet
1874 Control the use of the remote protocol `QTBuffer:size' packet.
1878 Control display of debugging messages related to ARM AArch64.
1881 set debug coff-pe-read
1882 show debug coff-pe-read
1883 Control display of debugging messages related to reading of COFF/PE
1888 Control display of debugging messages related to Mach-O symbols
1891 set debug notification
1892 show debug notification
1893 Control display of debugging info for async remote notification.
1897 ** Command parameter changes are now notified using new async record
1898 "=cmd-param-changed".
1899 ** Trace frame changes caused by command "tfind" are now notified using
1900 new async record "=traceframe-changed".
1901 ** The creation, deletion and modification of trace state variables
1902 are now notified using new async records "=tsv-created",
1903 "=tsv-deleted" and "=tsv-modified".
1904 ** The start and stop of process record are now notified using new
1905 async record "=record-started" and "=record-stopped".
1906 ** Memory changes are now notified using new async record
1908 ** The data-disassemble command response will include a "fullname" field
1909 containing the absolute file name when source has been requested.
1910 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1911 command, to allow pattern filling of memory areas.
1912 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1913 library load/unload events.
1914 ** The response to breakpoint commands and breakpoint async records
1915 includes an "installed" field containing a boolean state about each
1916 non-pending tracepoint location is whether installed on target or not.
1917 ** Output of the "-trace-status" command includes a "trace-file" field
1918 containing the name of the trace file being examined. This field is
1919 optional, and only present when examining a trace file.
1920 ** The "fullname" field is now always present along with the "file" field,
1921 even if the file cannot be found by GDB.
1923 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1924 You must have the LZMA library available when configuring GDB for this
1925 feature to be enabled. For more information, see:
1926 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1928 * New remote packets
1931 Set the size of trace buffer. The remote stub reports support for this
1932 packet to gdb's qSupported query.
1935 Enable Branch Trace Store (BTS)-based branch tracing for the current
1936 thread. The remote stub reports support for this packet to gdb's
1940 Disable branch tracing for the current thread. The remote stub reports
1941 support for this packet to gdb's qSupported query.
1944 Read the traced branches for the current thread. The remote stub
1945 reports support for this packet to gdb's qSupported query.
1947 *** Changes in GDB 7.5
1949 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1950 for more x32 ABI info.
1952 * GDB now supports access to MIPS DSP registers on Linux targets.
1954 * GDB now supports debugging microMIPS binaries.
1956 * The "info os" command on GNU/Linux can now display information on
1957 several new classes of objects managed by the operating system:
1958 "info os procgroups" lists process groups
1959 "info os files" lists file descriptors
1960 "info os sockets" lists internet-domain sockets
1961 "info os shm" lists shared-memory regions
1962 "info os semaphores" lists semaphores
1963 "info os msg" lists message queues
1964 "info os modules" lists loaded kernel modules
1966 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1967 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1968 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1969 options and inspect the probe arguments using the new $_probe_arg family
1970 of convenience variables. You can obtain more information about SystemTap
1971 in <http://sourceware.org/systemtap/>.
1973 * GDB now supports reversible debugging on ARM, it allows you to
1974 debug basic ARM and THUMB instructions, and provides
1975 record/replay support.
1977 * The option "symbol-reloading" has been deleted as it is no longer used.
1981 ** GDB commands implemented in Python can now be put in command class
1984 ** The "maint set python print-stack on|off" is now deleted.
1986 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1987 apply "flag enum"-style pretty-printing to any enum.
1989 ** gdb.lookup_symbol can now work when there is no current frame.
1991 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1992 the source at which the symbol was defined.
1994 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1995 method 'value'. The former indicates whether the symbol needs a
1996 frame in order to compute its value, and the latter computes the
1999 ** A new method 'referenced_value' on gdb.Value objects which can
2000 dereference pointer as well as C++ reference values.
2002 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2003 which return the global and static blocks (as gdb.Block objects),
2004 of the underlying symbol table, respectively.
2006 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2007 object associated with a PC value.
2009 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2010 of the address range occupied by code for the current source line.
2012 * Go language support.
2013 GDB now supports debugging programs written in the Go programming
2016 * GDBserver now supports stdio connections.
2017 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2019 * The binary "gdbtui" can no longer be built or installed.
2020 Use "gdb -tui" instead.
2022 * GDB will now print "flag" enums specially. A flag enum is one where
2023 all the enumerator values have no bits in common when pairwise
2024 "and"ed. When printing a value whose type is a flag enum, GDB will
2025 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2026 (gdb) print (enum E) 3
2029 * The filename part of a linespec will now match trailing components
2030 of a source file name. For example, "break gcc/expr.c:1000" will
2031 now set a breakpoint in build/gcc/expr.c, but not
2032 build/libcpp/expr.c.
2034 * The "info proc" and "generate-core-file" commands will now also
2035 work on remote targets connected to GDBserver on Linux.
2037 * The command "info catch" has been removed. It has been disabled
2038 since December 2007.
2040 * The "catch exception" and "catch assert" commands now accept
2041 a condition at the end of the command, much like the "break"
2042 command does. For instance:
2044 (gdb) catch exception Constraint_Error if Barrier = True
2046 Previously, it was possible to add a condition to such catchpoints,
2047 but it had to be done as a second step, after the catchpoint had been
2048 created, using the "condition" command.
2050 * The "info static-tracepoint-marker" command will now also work on
2051 native Linux targets with in-process agent.
2053 * GDB can now set breakpoints on inlined functions.
2055 * The .gdb_index section has been updated to include symbols for
2056 inlined functions. GDB will ignore older .gdb_index sections by
2057 default, which could cause symbol files to be loaded more slowly
2058 until their .gdb_index sections can be recreated. The new command
2059 "set use-deprecated-index-sections on" will cause GDB to use any older
2060 .gdb_index sections it finds. This will restore performance, but the
2061 ability to set breakpoints on inlined functions will be lost in symbol
2062 files with older .gdb_index sections.
2064 The .gdb_index section has also been updated to record more information
2065 about each symbol. This speeds up the "info variables", "info functions"
2066 and "info types" commands when used with programs having the .gdb_index
2067 section, as well as speeding up debugging with shared libraries using
2068 the .gdb_index section.
2070 * Ada support for GDB/MI Variable Objects has been added.
2072 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2077 ** New command -info-os is the MI equivalent of "info os".
2079 ** Output logs ("set logging" and related) now include MI output.
2083 ** "set use-deprecated-index-sections on|off"
2084 "show use-deprecated-index-sections on|off"
2085 Controls the use of deprecated .gdb_index sections.
2087 ** "catch load" and "catch unload" can be used to stop when a shared
2088 library is loaded or unloaded, respectively.
2090 ** "enable count" can be used to auto-disable a breakpoint after
2093 ** "info vtbl" can be used to show the virtual method tables for
2094 C++ and Java objects.
2096 ** "explore" and its sub commands "explore value" and "explore type"
2097 can be used to recursively explore values and types of
2098 expressions. These commands are available only if GDB is
2099 configured with '--with-python'.
2101 ** "info auto-load" shows status of all kinds of auto-loaded files,
2102 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2103 sequences of commands files, "info auto-load python-scripts"
2104 shows status of auto-loading Python script files,
2105 "info auto-load local-gdbinit" shows status of loading init file
2106 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2107 status of inferior specific thread debugging shared library loading.
2109 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2110 and "show auto-load-scripts" commands have been deprecated, use their
2111 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2112 and "show auto-load python-scripts" counterparts instead.
2114 ** "dprintf location,format,args..." creates a dynamic printf, which
2115 is basically a breakpoint that does a printf and immediately
2116 resumes your program's execution, so it is like a printf that you
2117 can insert dynamically at runtime instead of at compiletime.
2119 ** "set print symbol"
2121 Controls whether GDB attempts to display the symbol, if any,
2122 corresponding to addresses it prints. This defaults to "on", but
2123 you can set it to "off" to restore GDB's previous behavior.
2125 * Deprecated commands
2127 ** For the Renesas Super-H architecture, the "regs" command has been
2128 deprecated, and "info all-registers" should be used instead.
2132 Renesas RL78 rl78-*-elf
2133 HP OpenVMS ia64 ia64-hp-openvms*
2135 * GDBserver supports evaluation of breakpoint conditions. When
2136 support is advertised by GDBserver, GDB may be told to send the
2137 breakpoint conditions in bytecode form to GDBserver. GDBserver
2138 will only report the breakpoint trigger to GDB when its condition
2143 set mips compression
2144 show mips compression
2145 Select the compressed ISA encoding used in functions that have no symbol
2146 information available. The encoding can be set to either of:
2149 and is updated automatically from ELF file flags if available.
2151 set breakpoint condition-evaluation
2152 show breakpoint condition-evaluation
2153 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2154 GDBserver ("target"). Default option "auto" chooses the most efficient
2156 This option can improve debugger efficiency depending on the speed of the
2160 Disable auto-loading globally.
2163 Show auto-loading setting of all kinds of auto-loaded files.
2165 set auto-load gdb-scripts on|off
2166 show auto-load gdb-scripts
2167 Control auto-loading of GDB canned sequences of commands files.
2169 set auto-load python-scripts on|off
2170 show auto-load python-scripts
2171 Control auto-loading of Python script files.
2173 set auto-load local-gdbinit on|off
2174 show auto-load local-gdbinit
2175 Control loading of init file (.gdbinit) from current directory.
2177 set auto-load libthread-db on|off
2178 show auto-load libthread-db
2179 Control auto-loading of inferior specific thread debugging shared library.
2181 set auto-load scripts-directory <dir1>[:<dir2>...]
2182 show auto-load scripts-directory
2183 Set a list of directories from which to load auto-loaded scripts.
2184 Automatically loaded Python scripts and GDB scripts are located in one
2185 of the directories listed by this option.
2186 The delimiter (':' above) may differ according to the host platform.
2188 set auto-load safe-path <dir1>[:<dir2>...]
2189 show auto-load safe-path
2190 Set a list of directories from which it is safe to auto-load files.
2191 The delimiter (':' above) may differ according to the host platform.
2193 set debug auto-load on|off
2194 show debug auto-load
2195 Control display of debugging info for auto-loading the files above.
2197 set dprintf-style gdb|call|agent
2199 Control the way in which a dynamic printf is performed; "gdb"
2200 requests a GDB printf command, while "call" causes dprintf to call a
2201 function in the inferior. "agent" requests that the target agent
2202 (such as GDBserver) do the printing.
2204 set dprintf-function <expr>
2205 show dprintf-function
2206 set dprintf-channel <expr>
2207 show dprintf-channel
2208 Set the function and optional first argument to the call when using
2209 the "call" style of dynamic printf.
2211 set disconnected-dprintf on|off
2212 show disconnected-dprintf
2213 Control whether agent-style dynamic printfs continue to be in effect
2214 after GDB disconnects.
2216 * New configure options
2218 --with-auto-load-dir
2219 Configure default value for the 'set auto-load scripts-directory'
2220 setting above. It defaults to '$debugdir:$datadir/auto-load',
2221 $debugdir representing global debugging info directories (available
2222 via 'show debug-file-directory') and $datadir representing GDB's data
2223 directory (available via 'show data-directory').
2225 --with-auto-load-safe-path
2226 Configure default value for the 'set auto-load safe-path' setting
2227 above. It defaults to the --with-auto-load-dir setting.
2229 --without-auto-load-safe-path
2230 Set 'set auto-load safe-path' to '/', effectively disabling this
2233 * New remote packets
2235 z0/z1 conditional breakpoints extension
2237 The z0/z1 breakpoint insertion packets have been extended to carry
2238 a list of conditional expressions over to the remote stub depending on the
2239 condition evaluation mode. The use of this extension can be controlled
2240 via the "set remote conditional-breakpoints-packet" command.
2244 Specify the signals which the remote stub may pass to the debugged
2245 program without GDB involvement.
2247 * New command line options
2249 --init-command=FILE, -ix Like --command, -x but execute it
2250 before loading inferior.
2251 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2252 execute it before loading inferior.
2254 *** Changes in GDB 7.4
2256 * GDB now handles ambiguous linespecs more consistently; the existing
2257 FILE:LINE support has been expanded to other types of linespecs. A
2258 breakpoint will now be set on all matching locations in all
2259 inferiors, and locations will be added or removed according to
2262 * GDB now allows you to skip uninteresting functions and files when
2263 stepping with the "skip function" and "skip file" commands.
2265 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2266 and "show remote hardware-watchpoint-length-limit". These allows to
2267 set or show the maximum length limit (in bytes) of a remote
2268 target hardware watchpoint.
2270 This allows e.g. to use "unlimited" hardware watchpoints with the
2271 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2272 watchpoints are slower than real hardware watchpoints but are
2273 significantly faster than gdb software watchpoints.
2277 ** The register_pretty_printer function in module gdb.printing now takes
2278 an optional `replace' argument. If True, the new printer replaces any
2281 ** The "maint set python print-stack on|off" command has been
2282 deprecated and will be deleted in GDB 7.5.
2283 A new command: "set python print-stack none|full|message" has
2284 replaced it. Additionally, the default for "print-stack" is
2285 now "message", which just prints the error message without
2288 ** A prompt substitution hook (prompt_hook) is now available to the
2291 ** A new Python module, gdb.prompt has been added to the GDB Python
2292 modules library. This module provides functionality for
2293 escape sequences in prompts (used by set/show
2294 extended-prompt). These escape sequences are replaced by their
2295 corresponding value.
2297 ** Python commands and convenience-functions located in
2298 'data-directory'/python/gdb/command and
2299 'data-directory'/python/gdb/function are now automatically loaded
2302 ** Blocks now provide four new attributes. global_block and
2303 static_block will return the global and static blocks
2304 respectively. is_static and is_global are boolean attributes
2305 that indicate if the block is one of those two types.
2307 ** Symbols now provide the "type" attribute, the type of the symbol.
2309 ** The "gdb.breakpoint" function has been deprecated in favor of
2312 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2313 of a function. This class is based on the "finish" command
2314 available in the CLI.
2316 ** Type objects for struct and union types now allow access to
2317 the fields using standard Python dictionary (mapping) methods.
2318 For example, "some_type['myfield']" now works, as does
2319 "some_type.items()".
2321 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2324 ** A new function, "deep_items" has been added to the gdb.types
2325 module in the GDB Python modules library. This function returns
2326 an iterator over the fields of a struct or union type. Unlike
2327 the standard Python "iteritems" method, it will recursively traverse
2328 any anonymous fields.
2332 ** "*stopped" events can report several new "reason"s, such as
2335 ** Breakpoint changes are now notified using new async records, like
2336 "=breakpoint-modified".
2338 ** New command -ada-task-info.
2340 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2341 $sdir specifies the default system locations of shared libraries.
2342 $pdir specifies the directory where the libpthread used by the application
2345 GDB no longer looks in $sdir and $pdir after it has searched the directories
2346 mentioned in libthread-db-search-path. If you want to search those
2347 directories, they must be specified in libthread-db-search-path.
2348 The default value of libthread-db-search-path on GNU/Linux and Solaris
2349 systems is now "$sdir:$pdir".
2351 $pdir is not supported by gdbserver, it is currently ignored.
2352 $sdir is supported by gdbserver.
2354 * New configure option --with-iconv-bin.
2355 When using the internationalization support like the one in the GNU C
2356 library, GDB will invoke the "iconv" program to get a list of supported
2357 character sets. If this program lives in a non-standard location, one can
2358 use this option to specify where to find it.
2360 * When natively debugging programs on PowerPC BookE processors running
2361 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2362 watchpoints, which specify a mask in addition to an address to watch.
2363 The mask specifies that some bits of an address (the bits which are
2364 reset in the mask) should be ignored when matching the address accessed
2365 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2366 section in the user manual for more details.
2368 * The new option --once causes GDBserver to stop listening for connections once
2369 the first connection is made. The listening port used by GDBserver will
2370 become available after that.
2372 * New commands "info macros" and "alias" have been added.
2374 * New function parameters suffix @entry specifies value of function parameter
2375 at the time the function got called. Entry values are available only since
2381 "!" is now an alias of the "shell" command.
2382 Note that no space is needed between "!" and SHELL COMMAND.
2386 watch EXPRESSION mask MASK_VALUE
2387 The watch command now supports the mask argument which allows creation
2388 of masked watchpoints, if the current architecture supports this feature.
2390 info auto-load-scripts [REGEXP]
2391 This command was formerly named "maintenance print section-scripts".
2392 It is now generally useful and is no longer a maintenance-only command.
2394 info macro [-all] [--] MACRO
2395 The info macro command has new options `-all' and `--'. The first for
2396 printing all definitions of a macro. The second for explicitly specifying
2397 the end of arguments and the beginning of the macro name in case the macro
2398 name starts with a hyphen.
2400 collect[/s] EXPRESSIONS
2401 The tracepoint collect command now takes an optional modifier "/s"
2402 that directs it to dereference pointer-to-character types and
2403 collect the bytes of memory up to a zero byte. The behavior is
2404 similar to what you see when you use the regular print command on a
2405 string. An optional integer following the "/s" sets a bound on the
2406 number of bytes that will be collected.
2409 The trace start command now interprets any supplied arguments as a
2410 note to be recorded with the trace run, with an effect similar to
2411 setting the variable trace-notes.
2414 The trace stop command now interprets any arguments as a note to be
2415 mentioned along with the tstatus report that the trace was stopped
2416 with a command. The effect is similar to setting the variable
2419 * Tracepoints can now be enabled and disabled at any time after a trace
2420 experiment has been started using the standard "enable" and "disable"
2421 commands. It is now possible to start a trace experiment with no enabled
2422 tracepoints; GDB will display a warning, but will allow the experiment to
2423 begin, assuming that tracepoints will be enabled as needed while the trace
2426 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2427 locations with 4-byte instructions, when they were previously
2428 limited to locations with instructions of 5 bytes or longer.
2432 set debug dwarf2-read
2433 show debug dwarf2-read
2434 Turns on or off display of debugging messages related to reading
2435 DWARF debug info. The default is off.
2437 set debug symtab-create
2438 show debug symtab-create
2439 Turns on or off display of debugging messages related to symbol table
2440 creation. The default is off.
2443 show extended-prompt
2444 Set the GDB prompt, and allow escape sequences to be inserted to
2445 display miscellaneous information (see 'help set extended-prompt'
2446 for the list of sequences). This prompt (and any information
2447 accessed through the escape sequences) is updated every time the
2448 prompt is displayed.
2450 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2451 show print entry-values
2452 Set printing of frame argument values at function entry. In some cases
2453 GDB can determine the value of function argument which was passed by the
2454 function caller, even if the value was modified inside the called function.
2456 set debug entry-values
2457 show debug entry-values
2458 Control display of debugging info for determining frame argument values at
2459 function entry and virtual tail call frames.
2461 set basenames-may-differ
2462 show basenames-may-differ
2463 Set whether a source file may have multiple base names.
2464 (A "base name" is the name of a file with the directory part removed.
2465 Example: The base name of "/home/user/hello.c" is "hello.c".)
2466 If set, GDB will canonicalize file names (e.g., expand symlinks)
2467 before comparing them. Canonicalization is an expensive operation,
2468 but it allows the same file be known by more than one base name.
2469 If not set (the default), all source files are assumed to have just
2470 one base name, and gdb will do file name comparisons more efficiently.
2476 Set a user name and notes for the current and any future trace runs.
2477 This is useful for long-running and/or disconnected traces, to
2478 inform others (or yourself) as to who is running the trace, supply
2479 contact information, or otherwise explain what is going on.
2481 set trace-stop-notes
2482 show trace-stop-notes
2483 Set a note attached to the trace run, that is displayed when the
2484 trace has been stopped by a tstop command. This is useful for
2485 instance as an explanation, if you are stopping a trace run that was
2486 started by someone else.
2488 * New remote packets
2492 Dynamically enable a tracepoint in a started trace experiment.
2496 Dynamically disable a tracepoint in a started trace experiment.
2500 Set the user and notes of the trace run.
2504 Query the current status of a tracepoint.
2508 Query the minimum length of instruction at which a fast tracepoint may
2511 * Dcache size (number of lines) and line-size are now runtime-configurable
2512 via "set dcache line" and "set dcache line-size" commands.
2516 Texas Instruments TMS320C6x tic6x-*-*
2520 Renesas RL78 rl78-*-elf
2522 *** Changes in GDB 7.3.1
2524 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2526 *** Changes in GDB 7.3
2528 * GDB has a new command: "thread find [REGEXP]".
2529 It finds the thread id whose name, target id, or thread extra info
2530 matches the given regular expression.
2532 * The "catch syscall" command now works on mips*-linux* targets.
2534 * The -data-disassemble MI command now supports modes 2 and 3 for
2535 dumping the instruction opcodes.
2537 * New command line options
2539 -data-directory DIR Specify DIR as the "data-directory".
2540 This is mostly for testing purposes.
2542 * The "maint set python auto-load on|off" command has been renamed to
2543 "set auto-load-scripts on|off".
2545 * GDB has a new command: "set directories".
2546 It is like the "dir" command except that it replaces the
2547 source path list instead of augmenting it.
2549 * GDB now understands thread names.
2551 On GNU/Linux, "info threads" will display the thread name as set by
2552 prctl or pthread_setname_np.
2554 There is also a new command, "thread name", which can be used to
2555 assign a name internally for GDB to display.
2558 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2559 has been integrated into GDB.
2563 ** The function gdb.Write now accepts an optional keyword 'stream'.
2564 This keyword, when provided, will direct the output to either
2565 stdout, stderr, or GDB's logging output.
2567 ** Parameters can now be be sub-classed in Python, and in particular
2568 you may implement the get_set_doc and get_show_doc functions.
2569 This improves how Parameter set/show documentation is processed
2570 and allows for more dynamic content.
2572 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2573 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2574 have an is_valid method.
2576 ** Breakpoints can now be sub-classed in Python, and in particular
2577 you may implement a 'stop' function that is executed each time
2578 the inferior reaches that breakpoint.
2580 ** New function gdb.lookup_global_symbol looks up a global symbol.
2582 ** GDB values in Python are now callable if the value represents a
2583 function. For example, if 'some_value' represents a function that
2584 takes two integer parameters and returns a value, you can call
2585 that function like so:
2587 result = some_value (10,20)
2589 ** Module gdb.types has been added.
2590 It contains a collection of utilities for working with gdb.Types objects:
2591 get_basic_type, has_field, make_enum_dict.
2593 ** Module gdb.printing has been added.
2594 It contains utilities for writing and registering pretty-printers.
2595 New classes: PrettyPrinter, SubPrettyPrinter,
2596 RegexpCollectionPrettyPrinter.
2597 New function: register_pretty_printer.
2599 ** New commands "info pretty-printers", "enable pretty-printer" and
2600 "disable pretty-printer" have been added.
2602 ** gdb.parameter("directories") is now available.
2604 ** New function gdb.newest_frame returns the newest frame in the
2607 ** The gdb.InferiorThread class has a new "name" attribute. This
2608 holds the thread's name.
2610 ** Python Support for Inferior events.
2611 Python scripts can add observers to be notified of events
2612 occurring in the process being debugged.
2613 The following events are currently supported:
2614 - gdb.events.cont Continue event.
2615 - gdb.events.exited Inferior exited event.
2616 - gdb.events.stop Signal received, and Breakpoint hit events.
2620 ** GDB now puts template parameters in scope when debugging in an
2621 instantiation. For example, if you have:
2623 template<int X> int func (void) { return X; }
2625 then if you step into func<5>, "print X" will show "5". This
2626 feature requires proper debuginfo support from the compiler; it
2627 was added to GCC 4.5.
2629 ** The motion commands "next", "finish", "until", and "advance" now
2630 work better when exceptions are thrown. In particular, GDB will
2631 no longer lose control of the inferior; instead, the GDB will
2632 stop the inferior at the point at which the exception is caught.
2633 This functionality requires a change in the exception handling
2634 code that was introduced in GCC 4.5.
2636 * GDB now follows GCC's rules on accessing volatile objects when
2637 reading or writing target state during expression evaluation.
2638 One notable difference to prior behavior is that "print x = 0"
2639 no longer generates a read of x; the value of the assignment is
2640 now always taken directly from the value being assigned.
2642 * GDB now has some support for using labels in the program's source in
2643 linespecs. For instance, you can use "advance label" to continue
2644 execution to a label.
2646 * GDB now has support for reading and writing a new .gdb_index
2647 section. This section holds a fast index of DWARF debugging
2648 information and can be used to greatly speed up GDB startup and
2649 operation. See the documentation for `save gdb-index' for details.
2651 * The "watch" command now accepts an optional "-location" argument.
2652 When used, this causes GDB to watch the memory referred to by the
2653 expression. Such a watchpoint is never deleted due to it going out
2656 * GDB now supports thread debugging of core dumps on GNU/Linux.
2658 GDB now activates thread debugging using the libthread_db library
2659 when debugging GNU/Linux core dumps, similarly to when debugging
2660 live processes. As a result, when debugging a core dump file, GDB
2661 is now able to display pthread_t ids of threads. For example, "info
2662 threads" shows the same output as when debugging the process when it
2663 was live. In earlier releases, you'd see something like this:
2666 * 1 LWP 6780 main () at main.c:10
2668 While now you see this:
2671 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2673 It is also now possible to inspect TLS variables when debugging core
2676 When debugging a core dump generated on a machine other than the one
2677 used to run GDB, you may need to point GDB at the correct
2678 libthread_db library with the "set libthread-db-search-path"
2679 command. See the user manual for more details on this command.
2681 * When natively debugging programs on PowerPC BookE processors running
2682 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2683 which stop execution of the inferior whenever it executes an instruction
2684 at any address within the specified range. See the "PowerPC Embedded"
2685 section in the user manual for more details.
2687 * New features in the GDB remote stub, GDBserver
2689 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2690 and i686 LynxOS (version 5.x).
2692 ** GDBserver is now supported on Blackfin Linux.
2694 * New native configurations
2696 ia64 HP-UX ia64-*-hpux*
2700 Analog Devices, Inc. Blackfin Processor bfin-*
2702 * Ada task switching is now supported on sparc-elf targets when
2703 debugging a program using the Ravenscar Profile. For more information,
2704 see the "Tasking Support when using the Ravenscar Profile" section
2705 in the GDB user manual.
2707 * Guile support was removed.
2709 * New features in the GNU simulator
2711 ** The --map-info flag lists all known core mappings.
2713 ** CFI flashes may be simulated via the "cfi" device.
2715 *** Changes in GDB 7.2
2717 * Shared library support for remote targets by default
2719 When GDB is configured for a generic, non-OS specific target, like
2720 for example, --target=arm-eabi or one of the many *-*-elf targets,
2721 GDB now queries remote stubs for loaded shared libraries using the
2722 `qXfer:libraries:read' packet. Previously, shared library support
2723 was always disabled for such configurations.
2727 ** Argument Dependent Lookup (ADL)
2729 In C++ ADL lookup directs function search to the namespaces of its
2730 arguments even if the namespace has not been imported.
2740 Here the compiler will search for `foo' in the namespace of 'b'
2741 and find A::foo. GDB now supports this. This construct is commonly
2742 used in the Standard Template Library for operators.
2744 ** Improved User Defined Operator Support
2746 In addition to member operators, GDB now supports lookup of operators
2747 defined in a namespace and imported with a `using' directive, operators
2748 defined in the global scope, operators imported implicitly from an
2749 anonymous namespace, and the ADL operators mentioned in the previous
2751 GDB now also supports proper overload resolution for all the previously
2752 mentioned flavors of operators.
2754 ** static const class members
2756 Printing of static const class members that are initialized in the
2757 class definition has been fixed.
2759 * Windows Thread Information Block access.
2761 On Windows targets, GDB now supports displaying the Windows Thread
2762 Information Block (TIB) structure. This structure is visible either
2763 by using the new command `info w32 thread-information-block' or, by
2764 dereferencing the new convenience variable named `$_tlb', a
2765 thread-specific pointer to the TIB. This feature is also supported
2766 when remote debugging using GDBserver.
2768 * Static tracepoints
2770 Static tracepoints are calls in the user program into a tracing
2771 library. One such library is a port of the LTTng kernel tracer to
2772 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2773 When debugging with GDBserver, GDB now supports combining the GDB
2774 tracepoint machinery with such libraries. For example: the user can
2775 use GDB to probe a static tracepoint marker (a call from the user
2776 program into the tracing library) with the new "strace" command (see
2777 "New commands" below). This creates a "static tracepoint" in the
2778 breakpoint list, that can be manipulated with the same feature set
2779 as fast and regular tracepoints. E.g., collect registers, local and
2780 global variables, collect trace state variables, and define
2781 tracepoint conditions. In addition, the user can collect extra
2782 static tracepoint marker specific data, by collecting the new
2783 $_sdata internal variable. When analyzing the trace buffer, you can
2784 inspect $_sdata like any other variable available to GDB. For more
2785 information, see the "Tracepoints" chapter in GDB user manual. New
2786 remote packets have been defined to support static tracepoints, see
2787 the "New remote packets" section below.
2789 * Better reconstruction of tracepoints after disconnected tracing
2791 GDB will attempt to download the original source form of tracepoint
2792 definitions when starting a trace run, and then will upload these
2793 upon reconnection to the target, resulting in a more accurate
2794 reconstruction of the tracepoints that are in use on the target.
2798 You can now exercise direct control over the ways that GDB can
2799 affect your program. For instance, you can disallow the setting of
2800 breakpoints, so that the program can run continuously (assuming
2801 non-stop mode). In addition, the "observer" variable is available
2802 to switch all of the different controls; in observer mode, GDB
2803 cannot affect the target's behavior at all, which is useful for
2804 tasks like diagnosing live systems in the field.
2806 * The new convenience variable $_thread holds the number of the
2809 * New remote packets
2813 Return the address of the Windows Thread Information Block of a given thread.
2817 In response to several of the tracepoint packets, the target may now
2818 also respond with a number of intermediate `qRelocInsn' request
2819 packets before the final result packet, to have GDB handle
2820 relocating an instruction to execute at a different address. This
2821 is particularly useful for stubs that support fast tracepoints. GDB
2822 reports support for this feature in the qSupported packet.
2826 List static tracepoint markers in the target program.
2830 List static tracepoint markers at a given address in the target
2833 qXfer:statictrace:read
2835 Read the static trace data collected (by a `collect $_sdata'
2836 tracepoint action). The remote stub reports support for this packet
2837 to gdb's qSupported query.
2841 Send the current settings of GDB's permission flags.
2845 Send part of the source (textual) form of a tracepoint definition,
2846 which includes location, conditional, and action list.
2848 * The source command now accepts a -s option to force searching for the
2849 script in the source search path even if the script name specifies
2852 * New features in the GDB remote stub, GDBserver
2854 - GDBserver now support tracepoints (including fast tracepoints, and
2855 static tracepoints). The feature is currently supported by the
2856 i386-linux and amd64-linux builds. See the "Tracepoints support
2857 in gdbserver" section in the manual for more information.
2859 GDBserver JIT compiles the tracepoint's conditional agent
2860 expression bytecode into native code whenever possible for low
2861 overhead dynamic tracepoints conditionals. For such tracepoints,
2862 an expression that examines program state is evaluated when the
2863 tracepoint is reached, in order to determine whether to capture
2864 trace data. If the condition is simple and false, processing the
2865 tracepoint finishes very quickly and no data is gathered.
2867 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2868 for static tracepoints support.
2870 - GDBserver now supports x86_64 Windows 64-bit debugging.
2872 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2873 it understands register description.
2875 * The --batch flag now disables pagination and queries.
2877 * X86 general purpose registers
2879 GDB now supports reading/writing byte, word and double-word x86
2880 general purpose registers directly. This means you can use, say,
2881 $ah or $ax to refer, respectively, to the byte register AH and
2882 16-bit word register AX that are actually portions of the 32-bit
2883 register EAX or 64-bit register RAX.
2885 * The `commands' command now accepts a range of breakpoints to modify.
2886 A plain `commands' following a command that creates multiple
2887 breakpoints affects all the breakpoints set by that command. This
2888 applies to breakpoints set by `rbreak', and also applies when a
2889 single `break' command creates multiple breakpoints (e.g.,
2890 breakpoints on overloaded c++ functions).
2892 * The `rbreak' command now accepts a filename specification as part of
2893 its argument, limiting the functions selected by the regex to those
2894 in the specified file.
2896 * Support for remote debugging Windows and SymbianOS shared libraries
2897 from Unix hosts has been improved. Non Windows GDB builds now can
2898 understand target reported file names that follow MS-DOS based file
2899 system semantics, such as file names that include drive letters and
2900 use the backslash character as directory separator. This makes it
2901 possible to transparently use the "set sysroot" and "set
2902 solib-search-path" on Unix hosts to point as host copies of the
2903 target's shared libraries. See the new command "set
2904 target-file-system-kind" described below, and the "Commands to
2905 specify files" section in the user manual for more information.
2909 eval template, expressions...
2910 Convert the values of one or more expressions under the control
2911 of the string template to a command line, and call it.
2913 set target-file-system-kind unix|dos-based|auto
2914 show target-file-system-kind
2915 Set or show the assumed file system kind for target reported file
2918 save breakpoints <filename>
2919 Save all current breakpoint definitions to a file suitable for use
2920 in a later debugging session. To read the saved breakpoint
2921 definitions, use the `source' command.
2923 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2926 info static-tracepoint-markers
2927 Display information about static tracepoint markers in the target.
2929 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2930 Define a static tracepoint by probing a marker at the given
2931 function, line, address, or marker ID.
2935 Enable and disable observer mode.
2937 set may-write-registers on|off
2938 set may-write-memory on|off
2939 set may-insert-breakpoints on|off
2940 set may-insert-tracepoints on|off
2941 set may-insert-fast-tracepoints on|off
2942 set may-interrupt on|off
2943 Set individual permissions for GDB effects on the target. Note that
2944 some of these settings can have undesirable or surprising
2945 consequences, particularly when changed in the middle of a session.
2946 For instance, disabling the writing of memory can prevent
2947 breakpoints from being inserted, cause single-stepping to fail, or
2948 even crash your program, if you disable after breakpoints have been
2949 inserted. However, GDB should not crash.
2951 set record memory-query on|off
2952 show record memory-query
2953 Control whether to stop the inferior if memory changes caused
2954 by an instruction cannot be recorded.
2959 The disassemble command now supports "start,+length" form of two arguments.
2963 ** GDB now provides a new directory location, called the python directory,
2964 where Python scripts written for GDB can be installed. The location
2965 of that directory is <data-directory>/python, where <data-directory>
2966 is the GDB data directory. For more details, see section `Scripting
2967 GDB using Python' in the manual.
2969 ** The GDB Python API now has access to breakpoints, symbols, symbol
2970 tables, program spaces, inferiors, threads and frame's code blocks.
2971 Additionally, GDB Parameters can now be created from the API, and
2972 manipulated via set/show in the CLI.
2974 ** New functions gdb.target_charset, gdb.target_wide_charset,
2975 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2977 ** New exception gdb.GdbError.
2979 ** Pretty-printers are now also looked up in the current program space.
2981 ** Pretty-printers can now be individually enabled and disabled.
2983 ** GDB now looks for names of Python scripts to auto-load in a
2984 special section named `.debug_gdb_scripts', in addition to looking
2985 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2987 * Tracepoint actions were unified with breakpoint commands. In particular,
2988 there are no longer differences in "info break" output for breakpoints and
2989 tracepoints and the "commands" command can be used for both tracepoints and
2990 regular breakpoints.
2994 ARM Symbian arm*-*-symbianelf*
2996 * D language support.
2997 GDB now supports debugging programs written in the D programming
3000 * GDB now supports the extended ptrace interface for PowerPC which is
3001 available since Linux kernel version 2.6.34. This automatically enables
3002 any hardware breakpoints and additional hardware watchpoints available in
3003 the processor. The old ptrace interface exposes just one hardware
3004 watchpoint and no hardware breakpoints.
3006 * GDB is now able to use the Data Value Compare (DVC) register available on
3007 embedded PowerPC processors to implement in hardware simple watchpoint
3008 conditions of the form:
3010 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3012 This works in native GDB running on Linux kernels with the extended ptrace
3013 interface mentioned above.
3015 *** Changes in GDB 7.1
3019 ** Namespace Support
3021 GDB now supports importing of namespaces in C++. This enables the
3022 user to inspect variables from imported namespaces. Support for
3023 namepace aliasing has also been added. So, if a namespace is
3024 aliased in the current scope (e.g. namepace C=A; ) the user can
3025 print variables using the alias (e.g. (gdb) print C::x).
3029 All known bugs relating to the printing of virtual base class were
3030 fixed. It is now possible to call overloaded static methods using a
3035 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3036 and reinterpret_cast<> are now handled by the C++ expression parser.
3040 Xilinx MicroBlaze microblaze-*-*
3045 Xilinx MicroBlaze microblaze
3048 * Multi-program debugging.
3050 GDB now has support for multi-program (a.k.a. multi-executable or
3051 multi-exec) debugging. This allows for debugging multiple inferiors
3052 simultaneously each running a different program under the same GDB
3053 session. See "Debugging Multiple Inferiors and Programs" in the
3054 manual for more information. This implied some user visible changes
3055 in the multi-inferior support. For example, "info inferiors" now
3056 lists inferiors that are not running yet or that have exited
3057 already. See also "New commands" and "New options" below.
3059 * New tracing features
3061 GDB's tracepoint facility now includes several new features:
3063 ** Trace state variables
3065 GDB tracepoints now include support for trace state variables, which
3066 are variables managed by the target agent during a tracing
3067 experiment. They are useful for tracepoints that trigger each
3068 other, so for instance one tracepoint can count hits in a variable,
3069 and then a second tracepoint has a condition that is true when the
3070 count reaches a particular value. Trace state variables share the
3071 $-syntax of GDB convenience variables, and can appear in both
3072 tracepoint actions and condition expressions. Use the "tvariable"
3073 command to create, and "info tvariables" to view; see "Trace State
3074 Variables" in the manual for more detail.
3078 GDB now includes an option for defining fast tracepoints, which
3079 targets may implement more efficiently, such as by installing a jump
3080 into the target agent rather than a trap instruction. The resulting
3081 speedup can be by two orders of magnitude or more, although the
3082 tradeoff is that some program locations on some target architectures
3083 might not allow fast tracepoint installation, for instance if the
3084 instruction to be replaced is shorter than the jump. To request a
3085 fast tracepoint, use the "ftrace" command, with syntax identical to
3086 the regular trace command.
3088 ** Disconnected tracing
3090 It is now possible to detach GDB from the target while it is running
3091 a trace experiment, then reconnect later to see how the experiment
3092 is going. In addition, a new variable disconnected-tracing lets you
3093 tell the target agent whether to continue running a trace if the
3094 connection is lost unexpectedly.
3098 GDB now has the ability to save the trace buffer into a file, and
3099 then use that file as a target, similarly to you can do with
3100 corefiles. You can select trace frames, print data that was
3101 collected in them, and use tstatus to display the state of the
3102 tracing run at the moment that it was saved. To create a trace
3103 file, use "tsave <filename>", and to use it, do "target tfile
3106 ** Circular trace buffer
3108 You can ask the target agent to handle the trace buffer as a
3109 circular buffer, discarding the oldest trace frames to make room for
3110 newer ones, by setting circular-trace-buffer to on. This feature may
3111 not be available for all target agents.
3116 The disassemble command, when invoked with two arguments, now requires
3117 the arguments to be comma-separated.
3120 The info variables command now displays variable definitions. Files
3121 which only declare a variable are not shown.
3124 The source command is now capable of sourcing Python scripts.
3125 This feature is dependent on the debugger being build with Python
3128 Related to this enhancement is also the introduction of a new command
3129 "set script-extension" (see below).
3131 * New commands (for set/show, see "New options" below)
3133 record save [<FILENAME>]
3134 Save a file (in core file format) containing the process record
3135 execution log for replay debugging at a later time.
3137 record restore <FILENAME>
3138 Restore the process record execution log that was saved at an
3139 earlier time, for replay debugging.
3141 add-inferior [-copies <N>] [-exec <FILENAME>]
3144 clone-inferior [-copies <N>] [ID]
3145 Make a new inferior ready to execute the same program another
3146 inferior has loaded.
3151 maint info program-spaces
3152 List the program spaces loaded into GDB.
3154 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3155 show remote interrupt-sequence
3156 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3157 as the sequence to the remote target in order to interrupt the execution.
3158 Ctrl-C is a default. Some system prefers BREAK which is high level of
3159 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3160 Magic SysRq g. It is BREAK signal and character 'g'.
3162 set remote interrupt-on-connect [on | off]
3163 show remote interrupt-on-connect
3164 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3165 remote target when gdb connects to it. This is needed when you debug
3168 set remotebreak [on | off]
3170 Deprecated. Use "set/show remote interrupt-sequence" instead.
3172 tvariable $NAME [ = EXP ]
3173 Create or modify a trace state variable.
3176 List trace state variables and their values.
3178 delete tvariable $NAME ...
3179 Delete one or more trace state variables.
3182 Evaluate the given expressions without collecting anything into the
3183 trace buffer. (Valid in tracepoint actions only.)
3185 ftrace FN / FILE:LINE / *ADDR
3186 Define a fast tracepoint at the given function, line, or address.
3188 * New expression syntax
3190 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3191 GDB now parses 0b101010 identically with 42.
3195 set follow-exec-mode new|same
3196 show follow-exec-mode
3197 Control whether GDB reuses the same inferior across an exec call or
3198 creates a new one. This is useful to be able to restart the old
3199 executable after the inferior having done an exec call.
3201 set default-collect EXPR, ...
3202 show default-collect
3203 Define a list of expressions to be collected at each tracepoint.
3204 This is a useful way to ensure essential items are not overlooked,
3205 such as registers or a critical global variable.
3207 set disconnected-tracing
3208 show disconnected-tracing
3209 If set to 1, the target is instructed to continue tracing if it
3210 loses its connection to GDB. If 0, the target is to stop tracing
3213 set circular-trace-buffer
3214 show circular-trace-buffer
3215 If set to on, the target is instructed to use a circular trace buffer
3216 and discard the oldest trace frames instead of stopping the trace due
3217 to a full trace buffer. If set to off, the trace stops when the buffer
3218 fills up. Some targets may not support this.
3220 set script-extension off|soft|strict
3221 show script-extension
3222 If set to "off", the debugger does not perform any script language
3223 recognition, and all sourced files are assumed to be GDB scripts.
3224 If set to "soft" (the default), files are sourced according to
3225 filename extension, falling back to GDB scripts if the first
3227 If set to "strict", files are sourced according to filename extension.
3229 set ada trust-PAD-over-XVS on|off
3230 show ada trust-PAD-over-XVS
3231 If off, activate a workaround against a bug in the debugging information
3232 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3233 the GCC sources for more information about the GNAT encoding and
3234 PAD types in particular). It is always safe to set this option to
3235 off, but this introduces a slight performance penalty. The default
3238 * Python API Improvements
3240 ** GDB provides the new class gdb.LazyString. This is useful in
3241 some pretty-printing cases. The new method gdb.Value.lazy_string
3242 provides a simple way to create objects of this type.
3244 ** The fields returned by gdb.Type.fields now have an
3245 `is_base_class' attribute.
3247 ** The new method gdb.Type.range returns the range of an array type.
3249 ** The new method gdb.parse_and_eval can be used to parse and
3250 evaluate an expression.
3252 * New remote packets
3255 Define a trace state variable.
3258 Get the current value of a trace state variable.
3261 Set desired tracing behavior upon disconnection.
3264 Set the trace buffer to be linear or circular.
3267 Get data about the tracepoints currently in use.
3271 Process record now works correctly with hardware watchpoints.
3273 Multiple bug fixes have been made to the mips-irix port, making it
3274 much more reliable. In particular:
3275 - Debugging threaded applications is now possible again. Previously,
3276 GDB would hang while starting the program, or while waiting for
3277 the program to stop at a breakpoint.
3278 - Attaching to a running process no longer hangs.
3279 - An error occurring while loading a core file has been fixed.
3280 - Changing the value of the PC register now works again. This fixes
3281 problems observed when using the "jump" command, or when calling
3282 a function from GDB, or even when assigning a new value to $pc.
3283 - With the "finish" and "return" commands, the return value for functions
3284 returning a small array is now correctly printed.
3285 - It is now possible to break on shared library code which gets executed
3286 during a shared library init phase (code executed while executing
3287 their .init section). Previously, the breakpoint would have no effect.
3288 - GDB is now able to backtrace through the signal handler for
3289 non-threaded programs.
3291 PIE (Position Independent Executable) programs debugging is now supported.
3292 This includes debugging execution of PIC (Position Independent Code) shared
3293 libraries although for that, it should be possible to run such libraries as an
3296 *** Changes in GDB 7.0
3298 * GDB now has an interface for JIT compilation. Applications that
3299 dynamically generate code can create symbol files in memory and register
3300 them with GDB. For users, the feature should work transparently, and
3301 for JIT developers, the interface is documented in the GDB manual in the
3302 "JIT Compilation Interface" chapter.
3304 * Tracepoints may now be conditional. The syntax is as for
3305 breakpoints; either an "if" clause appended to the "trace" command,
3306 or the "condition" command is available. GDB sends the condition to
3307 the target for evaluation using the same bytecode format as is used
3308 for tracepoint actions.
3310 * The disassemble command now supports: an optional /r modifier, print the
3311 raw instructions in hex as well as in symbolic form, and an optional /m
3312 modifier to print mixed source+assembly.
3314 * Process record and replay
3316 In a architecture environment that supports ``process record and
3317 replay'', ``process record and replay'' target can record a log of
3318 the process execution, and replay it with both forward and reverse
3321 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3322 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3323 set execution-direction {forward|reverse}, for targets that support
3326 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3327 feature is available with a native GDB running on kernel version
3330 * GDB now has support for multi-byte and wide character sets on the
3331 target. Strings whose character type is wchar_t, char16_t, or
3332 char32_t are now correctly printed. GDB supports wide- and unicode-
3333 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3334 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3335 `printf'. This feature requires iconv to work properly; if your
3336 system does not have a working iconv, GDB can use GNU libiconv. See
3337 the installation instructions for more information.
3339 * GDB now supports automatic retrieval of shared library files from
3340 remote targets. To use this feature, specify a system root that begins
3341 with the `remote:' prefix, either via the `set sysroot' command or via
3342 the `--with-sysroot' configure-time option.
3344 * "info sharedlibrary" now takes an optional regex of libraries to show,
3345 and it now reports if a shared library has no debugging information.
3347 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3348 now complete on file names.
3350 * When completing in expressions, gdb will attempt to limit
3351 completions to allowable structure or union fields, where appropriate.
3352 For instance, consider:
3354 # struct example { int f1; double f2; };
3355 # struct example variable;
3358 If the user types TAB at the end of this command line, the available
3359 completions will be "f1" and "f2".
3361 * Inlined functions are now supported. They show up in backtraces, and
3362 the "step", "next", and "finish" commands handle them automatically.
3364 * GDB now supports the token-splicing (##) and stringification (#)
3365 operators when expanding macros. It also supports variable-arity
3368 * GDB now supports inspecting extra signal information, exported by
3369 the new $_siginfo convenience variable. The feature is currently
3370 implemented on linux ARM, i386 and amd64.
3372 * GDB can now display the VFP floating point registers and NEON vector
3373 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3374 can provide these registers (requires Linux 2.6.30 or later). Remote
3375 and simulator targets may also provide them.
3377 * New remote packets
3380 Search memory for a sequence of bytes.
3383 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3384 operation over reliable transport links. Use of this packet is
3385 controlled by the `set remote noack-packet' command.
3388 Kill the process with the specified process ID. Use this in preference
3389 to `k' when multiprocess protocol extensions are supported.
3392 Obtains additional operating system information
3396 Read or write additional signal information.
3398 * Removed remote protocol undocumented extension
3400 An undocumented extension to the remote protocol's `S' stop reply
3401 packet that permited the stub to pass a process id was removed.
3402 Remote servers should use the `T' stop reply packet instead.
3404 * GDB now supports multiple function calling conventions according to the
3405 DWARF-2 DW_AT_calling_convention function attribute.
3407 * The SH target utilizes the aforementioned change to distinguish between gcc
3408 and Renesas calling convention. It also adds the new CLI commands
3409 `set/show sh calling-convention'.
3411 * GDB can now read compressed debug sections, as produced by GNU gold
3412 with the --compress-debug-sections=zlib flag.
3414 * 64-bit core files are now supported on AIX.
3416 * Thread switching is now supported on Tru64.
3418 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3419 which will be allocated using malloc later in program execution.
3421 * The qXfer:libraries:read remote procotol packet now allows passing a
3422 list of section offsets.
3424 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3425 conditions handling signals delivered during attach or thread creation
3426 have also been fixed.
3428 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3429 From the user's standpoint, all unqualified instances of True and False
3430 are treated as the standard definitions, regardless of context.
3432 * GDB now parses C++ symbol and type names more flexibly. For
3435 template<typename T> class C { };
3438 GDB will now correctly handle all of:
3440 ptype C<char const *>
3441 ptype C<char const*>
3442 ptype C<const char *>
3443 ptype C<const char*>
3445 * New features in the GDB remote stub, gdbserver
3447 - The "--wrapper" command-line argument tells gdbserver to use a
3448 wrapper program to launch programs for debugging.
3450 - On PowerPC and S/390 targets, it is now possible to use a single
3451 gdbserver executable to debug both 32-bit and 64-bit programs.
3452 (This requires gdbserver itself to be built as a 64-bit executable.)
3454 - gdbserver uses the new noack protocol mode for TCP connections to
3455 reduce communications latency, if also supported and enabled in GDB.
3457 - Support for the sparc64-linux-gnu target is now included in
3460 - The amd64-linux build of gdbserver now supports debugging both
3461 32-bit and 64-bit programs.
3463 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3464 now support hardware watchpoints, and will use them automatically
3469 GDB now has support for scripting using Python. Whether this is
3470 available is determined at configure time.
3472 New GDB commands can now be written in Python.
3474 * Ada tasking support
3476 Ada tasks can now be inspected in GDB. The following commands have
3480 Print the list of Ada tasks.
3482 Print detailed information about task number N.
3484 Print the task number of the current task.
3486 Switch the context of debugging to task number N.
3488 * Support for user-defined prefixed commands. The "define" command can
3489 add new commands to existing prefixes, e.g. "target".
3491 * Multi-inferior, multi-process debugging.
3493 GDB now has generalized support for multi-inferior debugging. See
3494 "Debugging Multiple Inferiors" in the manual for more information.
3495 Although availability still depends on target support, the command
3496 set is more uniform now. The GNU/Linux specific multi-forks support
3497 has been migrated to this new framework. This implied some user
3498 visible changes; see "New commands" and also "Removed commands"
3501 * Target descriptions can now describe the target OS ABI. See the
3502 "Target Description Format" section in the user manual for more
3505 * Target descriptions can now describe "compatible" architectures
3506 to indicate that the target can execute applications for a different
3507 architecture in addition to those for the main target architecture.
3508 See the "Target Description Format" section in the user manual for
3511 * Multi-architecture debugging.
3513 GDB now includes general supports for debugging applications on
3514 hybrid systems that use more than one single processor architecture
3515 at the same time. Each such hybrid architecture still requires
3516 specific support to be added. The only hybrid architecture supported
3517 in this version of GDB is the Cell Broadband Engine.
3519 * GDB now supports integrated debugging of Cell/B.E. applications that
3520 use both the PPU and SPU architectures. To enable support for hybrid
3521 Cell/B.E. debugging, you need to configure GDB to support both the
3522 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3523 --enable-targets configure option.
3525 * Non-stop mode debugging.
3527 For some targets, GDB now supports an optional mode of operation in
3528 which you can examine stopped threads while other threads continue
3529 to execute freely. This is referred to as non-stop mode, with the
3530 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3531 section in the user manual for more information.
3533 To be able to support remote non-stop debugging, a remote stub needs
3534 to implement the non-stop mode remote protocol extensions, as
3535 described in the "Remote Non-Stop" section of the user manual. The
3536 GDB remote stub, gdbserver, has been adjusted to support these
3537 extensions on linux targets.
3539 * New commands (for set/show, see "New options" below)
3541 catch syscall [NAME(S) | NUMBER(S)]
3542 Catch system calls. Arguments, which should be names of system
3543 calls or their numbers, mean catch only those syscalls. Without
3544 arguments, every syscall will be caught. When the inferior issues
3545 any of the specified syscalls, GDB will stop and announce the system
3546 call, both when it is called and when its call returns. This
3547 feature is currently available with a native GDB running on the
3548 Linux Kernel, under the following architectures: x86, x86_64,
3549 PowerPC and PowerPC64.
3551 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3553 Search memory for a sequence of bytes.
3555 maint set python print-stack
3556 maint show python print-stack
3557 Show a stack trace when an error is encountered in a Python script.
3560 Invoke CODE by passing it to the Python interpreter.
3565 These allow macros to be defined, undefined, and listed
3569 Show operating system information about processes.
3572 List the inferiors currently under GDB's control.
3575 Switch focus to inferior number NUM.
3578 Detach from inferior number NUM.
3581 Kill inferior number NUM.
3585 set spu stop-on-load
3586 show spu stop-on-load
3587 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3589 set spu auto-flush-cache
3590 show spu auto-flush-cache
3591 Control whether to automatically flush the software-managed cache
3592 during Cell/B.E. debugging.
3594 set sh calling-convention
3595 show sh calling-convention
3596 Control the calling convention used when calling SH target functions.
3599 show debug timestamp
3600 Control display of timestamps with GDB debugging output.
3602 set disassemble-next-line
3603 show disassemble-next-line
3604 Control display of disassembled source lines or instructions when
3607 set remote noack-packet
3608 show remote noack-packet
3609 Set/show the use of remote protocol QStartNoAckMode packet. See above
3610 under "New remote packets."
3612 set remote query-attached-packet
3613 show remote query-attached-packet
3614 Control use of remote protocol `qAttached' (query-attached) packet.
3616 set remote read-siginfo-object
3617 show remote read-siginfo-object
3618 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3621 set remote write-siginfo-object
3622 show remote write-siginfo-object
3623 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3626 set remote reverse-continue
3627 show remote reverse-continue
3628 Control use of remote protocol 'bc' (reverse-continue) packet.
3630 set remote reverse-step
3631 show remote reverse-step
3632 Control use of remote protocol 'bs' (reverse-step) packet.
3634 set displaced-stepping
3635 show displaced-stepping
3636 Control displaced stepping mode. Displaced stepping is a way to
3637 single-step over breakpoints without removing them from the debuggee.
3638 Also known as "out-of-line single-stepping".
3641 show debug displaced
3642 Control display of debugging info for displaced stepping.
3644 maint set internal-error
3645 maint show internal-error
3646 Control what GDB does when an internal error is detected.
3648 maint set internal-warning
3649 maint show internal-warning
3650 Control what GDB does when an internal warning is detected.
3655 Use a wrapper program to launch programs for debugging.
3657 set multiple-symbols (all|ask|cancel)
3658 show multiple-symbols
3659 The value of this variable can be changed to adjust the debugger behavior
3660 when an expression or a breakpoint location contains an ambiguous symbol
3661 name (an overloaded function name, for instance).
3663 set breakpoint always-inserted
3664 show breakpoint always-inserted
3665 Keep breakpoints always inserted in the target, as opposed to inserting
3666 them when resuming the target, and removing them when the target stops.
3667 This option can improve debugger performance on slow remote targets.
3669 set arm fallback-mode (arm|thumb|auto)
3670 show arm fallback-mode
3671 set arm force-mode (arm|thumb|auto)
3673 These commands control how ARM GDB determines whether instructions
3674 are ARM or Thumb. The default for both settings is auto, which uses
3675 the current CPSR value for instructions without symbols; previous
3676 versions of GDB behaved as if "set arm fallback-mode arm".
3678 set disable-randomization
3679 show disable-randomization
3680 Standalone programs run with the virtual address space randomization enabled
3681 by default on some platforms. This option keeps the addresses stable across
3682 multiple debugging sessions.
3686 Control whether other threads are stopped or not when some thread hits
3691 Requests that asynchronous execution is enabled in the target, if available.
3692 In this case, it's possible to resume target in the background, and interact
3693 with GDB while the target is running. "show target-async" displays the
3694 current state of asynchronous execution of the target.
3696 set target-wide-charset
3697 show target-wide-charset
3698 The target-wide-charset is the name of the character set that GDB
3699 uses when printing characters whose type is wchar_t.
3701 set tcp auto-retry (on|off)
3703 set tcp connect-timeout
3704 show tcp connect-timeout
3705 These commands allow GDB to retry failed TCP connections to a remote stub
3706 with a specified timeout period; this is useful if the stub is launched
3707 in parallel with GDB but may not be ready to accept connections immediately.
3709 set libthread-db-search-path
3710 show libthread-db-search-path
3711 Control list of directories which GDB will search for appropriate
3714 set schedule-multiple (on|off)
3715 show schedule-multiple
3716 Allow GDB to resume all threads of all processes or only threads of
3717 the current process.
3721 Use more aggressive caching for accesses to the stack. This improves
3722 performance of remote debugging (particularly backtraces) without
3723 affecting correctness.
3725 set interactive-mode (on|off|auto)
3726 show interactive-mode
3727 Control whether GDB runs in interactive mode (on) or not (off).
3728 When in interactive mode, GDB waits for the user to answer all
3729 queries. Otherwise, GDB does not wait and assumes the default
3730 answer. When set to auto (the default), GDB determines which
3731 mode to use based on the stdin settings.
3736 For program forks, this is replaced by the new more generic `info
3737 inferiors' command. To list checkpoints, you can still use the
3738 `info checkpoints' command, which was an alias for the `info forks'
3742 Replaced by the new `inferior' command. To switch between
3743 checkpoints, you can still use the `restart' command, which was an
3744 alias for the `fork' command.
3747 This is removed, since some targets don't have a notion of
3748 processes. To switch between processes, you can still use the
3749 `inferior' command using GDB's own inferior number.
3752 For program forks, this is replaced by the new more generic `kill
3753 inferior' command. To delete a checkpoint, you can still use the
3754 `delete checkpoint' command, which was an alias for the `delete
3758 For program forks, this is replaced by the new more generic `detach
3759 inferior' command. To detach a checkpoint, you can still use the
3760 `detach checkpoint' command, which was an alias for the `detach
3763 * New native configurations
3765 x86/x86_64 Darwin i[34567]86-*-darwin*
3767 x86_64 MinGW x86_64-*-mingw*
3771 Lattice Mico32 lm32-*
3772 x86 DICOS i[34567]86-*-dicos*
3773 x86_64 DICOS x86_64-*-dicos*
3776 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3777 (mingw32ce) debugging.
3783 These commands were actually not implemented on any target.
3785 *** Changes in GDB 6.8
3787 * New native configurations
3789 NetBSD/hppa hppa*-*netbsd*
3790 Xtensa GNU/Linux xtensa*-*-linux*
3794 NetBSD/hppa hppa*-*-netbsd*
3795 Xtensa GNU/Lunux xtensa*-*-linux*
3797 * Change in command line behavior -- corefiles vs. process ids.
3799 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3800 attaching to process NUMBER fails, GDB no longer attempts to open a
3801 core file named NUMBER. Attaching to a program using the -c option
3802 is no longer supported. Instead, use the '-p' or '--pid' options.
3804 * GDB can now be built as a native debugger for debugging Windows x86
3805 (mingw32) Portable Executable (PE) programs.
3807 * Pending breakpoints no longer change their number when their address
3810 * GDB now supports breakpoints with multiple locations,
3811 including breakpoints on C++ constructors, inside C++ templates,
3812 and in inlined functions.
3814 * GDB's ability to debug optimized code has been improved. GDB more
3815 accurately identifies function bodies and lexical blocks that occupy
3816 more than one contiguous range of addresses.
3818 * Target descriptions can now describe registers for PowerPC.
3820 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3821 registers on PowerPC targets.
3823 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3824 targets even when the libthread_db library is not available.
3826 * The GDB remote stub, gdbserver, now supports the new file transfer
3827 commands (remote put, remote get, and remote delete).
3829 * The GDB remote stub, gdbserver, now supports run and attach in
3830 extended-remote mode.
3832 * hppa*64*-*-hpux11* target broken
3833 The debugger is unable to start a program and fails with the following
3834 error: "Error trying to get information about dynamic linker".
3835 The gdb-6.7 release is also affected.
3837 * GDB now supports the --enable-targets= configure option to allow
3838 building a single GDB executable that supports multiple remote
3839 target architectures.
3841 * GDB now supports debugging C and C++ programs which use the
3842 Decimal Floating Point extension. In addition, the PowerPC target
3843 now has a set of pseudo-registers to inspect decimal float values
3844 stored in two consecutive float registers.
3846 * The -break-insert MI command can optionally create pending
3849 * Improved support for debugging Ada
3850 Many improvements to the Ada language support have been made. These
3852 - Better support for Ada2005 interface types
3853 - Improved handling of arrays and slices in general
3854 - Better support for Taft-amendment types
3855 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3857 - Improved command completion in Ada
3860 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3865 set print frame-arguments (all|scalars|none)
3866 show print frame-arguments
3867 The value of this variable can be changed to control which argument
3868 values should be printed by the debugger when displaying a frame.
3873 Transfer files to and from a remote target, and delete remote files.
3880 Transfer files to and from a remote target, and delete remote files.
3882 * New remote packets
3889 Open, close, read, write, and delete files on the remote system.
3892 Attach to an existing process on the remote system, in extended-remote
3896 Run a new process on the remote system, in extended-remote mode.
3898 *** Changes in GDB 6.7
3900 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3901 bfd, libiberty and opcodes, as revealed by static analysis donated by
3902 Coverity, Inc. (http://scan.coverity.com).
3904 * When looking up multiply-defined global symbols, GDB will now prefer the
3905 symbol definition in the current shared library if it was built using the
3906 -Bsymbolic linker option.
3908 * When the Text User Interface (TUI) is not configured, GDB will now
3909 recognize the -tui command-line option and print a message that the TUI
3912 * The GDB remote stub, gdbserver, now has lower overhead for high
3913 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3915 * GDB for MIPS targets now autodetects whether a remote target provides
3916 32-bit or 64-bit register values.
3918 * Support for C++ member pointers has been improved.
3920 * GDB now understands XML target descriptions, which specify the
3921 target's overall architecture. GDB can read a description from
3922 a local file or over the remote serial protocol.
3924 * Vectors of single-byte data use a new integer type which is not
3925 automatically displayed as character or string data.
3927 * The /s format now works with the print command. It displays
3928 arrays of single-byte integers and pointers to single-byte integers
3931 * Target descriptions can now describe target-specific registers,
3932 for architectures which have implemented the support (currently
3933 only ARM, M68K, and MIPS).
3935 * GDB and the GDB remote stub, gdbserver, now support the XScale
3938 * The GDB remote stub, gdbserver, has been updated to support
3939 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3940 has been rewritten to use the standard GDB remote protocol.
3942 * GDB can now step into C++ functions which are called through thunks.
3944 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3946 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3947 layout. It also supports a TextSeg= and DataSeg= response when only
3948 segment base addresses (rather than offsets) are available.
3950 * The /i format now outputs any trailing branch delay slot instructions
3951 immediately following the last instruction within the count specified.
3953 * The GDB remote protocol "T" stop reply packet now supports a
3954 "library" response. Combined with the new "qXfer:libraries:read"
3955 packet, this response allows GDB to debug shared libraries on targets
3956 where the operating system manages the list of loaded libraries (e.g.
3957 Windows and SymbianOS).
3959 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3960 (DLLs) on Windows and Windows CE targets.
3962 * GDB now supports a faster verification that a .debug file matches its binary
3963 according to its build-id signature, if the signature is present.
3969 Enable or disable hardware flow control (RTS/CTS) on the serial port
3970 when debugging using remote targets.
3972 set mem inaccessible-by-default
3973 show mem inaccessible-by-default
3974 If the target supplies a memory map, for instance via the remote
3975 protocol's "qXfer:memory-map:read" packet, setting this variable
3976 prevents GDB from accessing memory outside the memory map. This
3977 is useful for targets with memory mapped registers or which react
3978 badly to accesses of unmapped address space.
3980 set breakpoint auto-hw
3981 show breakpoint auto-hw
3982 If the target supplies a memory map, for instance via the remote
3983 protocol's "qXfer:memory-map:read" packet, setting this variable
3984 lets GDB use hardware breakpoints automatically for memory regions
3985 where it can not use software breakpoints. This covers both the
3986 "break" command and internal breakpoints used for other commands
3987 including "next" and "finish".
3990 catch exception unhandled
3991 Stop the program execution when Ada exceptions are raised.
3994 Stop the program execution when an Ada assertion failed.
3998 Set an alternate system root for target files. This is a more
3999 general version of "set solib-absolute-prefix", which is now
4000 an alias to "set sysroot".
4003 Provide extended SPU facility status information. This set of
4004 commands is available only when debugging the Cell/B.E. SPU
4007 * New native configurations
4009 OpenBSD/sh sh*-*openbsd*
4012 unset tdesc filename
4014 Use the specified local file as an XML target description, and do
4015 not query the target for its built-in description.
4019 OpenBSD/sh sh*-*-openbsd*
4020 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4021 Toshiba Media Processor mep-elf
4023 * New remote packets
4026 Ignore the specified signals; pass them directly to the debugged program
4027 without stopping other threads or reporting them to GDB.
4029 qXfer:features:read:
4030 Read an XML target description from the target, which describes its
4035 Read or write contents of an spufs file on the target system. These
4036 packets are available only on the Cell/B.E. SPU architecture.
4038 qXfer:libraries:read:
4039 Report the loaded shared libraries. Combined with new "T" packet
4040 response, this packet allows GDB to debug shared libraries on
4041 targets where the operating system manages the list of loaded
4042 libraries (e.g. Windows and SymbianOS).
4046 Support for these obsolete configurations has been removed.
4054 i[34567]86-*-lynxos*
4055 i[34567]86-*-netware*
4056 i[34567]86-*-sco3.2v5*
4057 i[34567]86-*-sco3.2v4*
4059 i[34567]86-*-sysv4.2*
4062 i[34567]86-*-unixware2*
4063 i[34567]86-*-unixware*
4072 * Other removed features
4079 Various m68k-only ROM monitors.
4086 Various Renesas ROM monitors and debugging interfaces for SH and
4091 Support for a Macraigor serial interface to on-chip debugging.
4092 GDB does not directly support the newer parallel or USB
4097 A debug information format. The predecessor to DWARF 2 and
4098 DWARF 3, which are still supported.
4100 Support for the HP aCC compiler on HP-UX/PA-RISC
4102 SOM-encapsulated symbolic debugging information, automatic
4103 invocation of pxdb, and the aCC custom C++ ABI. This does not
4104 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4105 with aCC can still be debugged on an assembly level.
4107 MIPS ".pdr" sections
4109 A MIPS-specific format used to describe stack frame layout
4110 in debugging information.
4114 GDB could work with an older version of Guile to debug
4115 the interpreter and Scheme programs running in it.
4117 set mips stack-arg-size
4118 set mips saved-gpreg-size
4120 Use "set mips abi" to control parameter passing for MIPS.
4122 *** Changes in GDB 6.6
4127 Cell Broadband Engine SPU spu-elf
4129 * GDB can now be configured as a cross-debugger targeting native Windows
4130 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4131 running on a Windows system over TCP/IP to debug Windows programs.
4133 * The GDB remote stub, gdbserver, has been updated to support Windows and
4134 Cygwin debugging. Both single-threaded and multi-threaded programs are
4137 * The "set trust-readonly-sections" command works again. This command was
4138 broken in GDB 6.3, 6.4, and 6.5.
4140 * The "load" command now supports writing to flash memory, if the remote
4141 stub provides the required support.
4143 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4144 longer requires symbolic debug information (e.g. DWARF-2).
4149 unset substitute-path
4150 show substitute-path
4151 Manage a list of substitution rules that GDB uses to rewrite the name
4152 of the directories where the sources are located. This can be useful
4153 for instance when the sources were moved to a different location
4154 between compilation and debugging.
4158 Print each CLI command as it is executed. Each command is prefixed with
4159 a number of `+' symbols representing the nesting depth.
4160 The source command now has a `-v' option to enable the same feature.
4164 The ARM Demon monitor support (RDP protocol, "target rdp").
4166 Kernel Object Display, an embedded debugging feature which only worked with
4167 an obsolete version of Cisco IOS.
4169 The 'set download-write-size' and 'show download-write-size' commands.
4171 * New remote packets
4174 Tell a stub about GDB client features, and request remote target features.
4175 The first feature implemented is PacketSize, which allows the target to
4176 specify the size of packets it can handle - to minimize the number of
4177 packets required and improve performance when connected to a remote
4181 Fetch an OS auxilliary vector from the remote stub. This packet is a
4182 more efficient replacement for qPart:auxv:read.
4184 qXfer:memory-map:read:
4185 Fetch a memory map from the remote stub, including information about
4186 RAM, ROM, and flash memory devices.
4191 Erase and program a flash memory device.
4193 * Removed remote packets
4196 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4197 used it, and only gdbserver implemented it.
4199 *** Changes in GDB 6.5
4203 Renesas M32C/M16C m32c-elf
4205 Morpho Technologies ms1 ms1-elf
4209 init-if-undefined Initialize a convenience variable, but
4210 only if it doesn't already have a value.
4212 The following commands are presently only implemented for native GNU/Linux:
4214 checkpoint Save a snapshot of the program state.
4216 restart <n> Return the program state to a
4217 previously saved state.
4219 info checkpoints List currently saved checkpoints.
4221 delete-checkpoint <n> Delete a previously saved checkpoint.
4223 set|show detach-on-fork Tell gdb whether to detach from a newly
4224 forked process, or to keep debugging it.
4226 info forks List forks of the user program that
4227 are available to be debugged.
4229 fork <n> Switch to debugging one of several
4230 forks of the user program that are
4231 available to be debugged.
4233 delete-fork <n> Delete a fork from the list of forks
4234 that are available to be debugged (and
4235 kill the forked process).
4237 detach-fork <n> Delete a fork from the list of forks
4238 that are available to be debugged (and
4239 allow the process to continue).
4243 Morpho Technologies ms2 ms1-elf
4245 * Improved Windows host support
4247 GDB now builds as a cross debugger hosted on i686-mingw32, including
4248 native console support, and remote communications using either
4249 network sockets or serial ports.
4251 * Improved Modula-2 language support
4253 GDB can now print most types in the Modula-2 syntax. This includes:
4254 basic types, set types, record types, enumerated types, range types,
4255 pointer types and ARRAY types. Procedure var parameters are correctly
4256 printed and hexadecimal addresses and character constants are also
4257 written in the Modula-2 syntax. Best results can be obtained by using
4258 GNU Modula-2 together with the -gdwarf-2 command line option.
4262 The ARM rdi-share module.
4264 The Netware NLM debug server.
4266 *** Changes in GDB 6.4
4268 * New native configurations
4270 OpenBSD/arm arm*-*-openbsd*
4271 OpenBSD/mips64 mips64-*-openbsd*
4275 Morpho Technologies ms1 ms1-elf
4277 * New command line options
4279 --batch-silent As for --batch, but totally silent.
4280 --return-child-result The debugger will exist with the same value
4281 the child (debugged) program exited with.
4282 --eval-command COMMAND, -ex COMMAND
4283 Execute a single GDB CLI command. This may be
4284 specified multiple times and in conjunction
4285 with the --command (-x) option.
4287 * Deprecated commands removed
4289 The following commands, that were deprecated in 2000, have been
4293 set|show arm disassembly-flavor set|show arm disassembler
4294 othernames set arm disassembler
4295 set|show remotedebug set|show debug remote
4296 set|show archdebug set|show debug arch
4297 set|show eventdebug set|show debug event
4300 * New BSD user-level threads support
4302 It is now possible to debug programs using the user-level threads
4303 library on OpenBSD and FreeBSD. Currently supported (target)
4306 FreeBSD/amd64 x86_64-*-freebsd*
4307 FreeBSD/i386 i386-*-freebsd*
4308 OpenBSD/i386 i386-*-openbsd*
4310 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4311 are not yet supported.
4313 * New support for Matsushita MN10300 w/sim added
4314 (Work in progress). mn10300-elf.
4316 * REMOVED configurations and files
4318 VxWorks and the XDR protocol *-*-vxworks
4319 Motorola MCORE mcore-*-*
4320 National Semiconductor NS32000 ns32k-*-*
4322 * New "set print array-indexes" command
4324 After turning this setting "on", GDB prints the index of each element
4325 when displaying arrays. The default is "off" to preserve the previous
4328 * VAX floating point support
4330 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4332 * User-defined command support
4334 In addition to using $arg0..$arg9 for argument passing, it is now possible
4335 to use $argc to determine now many arguments have been passed. See the
4336 section on user-defined commands in the user manual for more information.
4338 *** Changes in GDB 6.3:
4340 * New command line option
4342 GDB now accepts -l followed by a number to set the timeout for remote
4345 * GDB works with GCC -feliminate-dwarf2-dups
4347 GDB now supports a more compact representation of DWARF-2 debug
4348 information using DW_FORM_ref_addr references. These are produced
4349 by GCC with the option -feliminate-dwarf2-dups and also by some
4350 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4351 to use -feliminate-dwarf2-dups.
4353 * Internationalization
4355 When supported by the host system, GDB will be built with
4356 internationalization (libintl). The task of marking up the sources is
4357 continued, we're looking forward to our first translation.
4361 Initial support for debugging programs compiled with the GNAT
4362 implementation of the Ada programming language has been integrated
4363 into GDB. In this release, support is limited to expression evaluation.
4365 * New native configurations
4367 GNU/Linux/m32r m32r-*-linux-gnu
4371 GDB's remote protocol now includes support for the 'p' packet. This
4372 packet is used to fetch individual registers from a remote inferior.
4374 * END-OF-LIFE registers[] compatibility module
4376 GDB's internal register infrastructure has been completely rewritten.
4377 The new infrastructure making possible the implementation of key new
4378 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4381 GDB 6.3 will be the last release to include the the registers[]
4382 compatibility module that allowed out-of-date configurations to
4383 continue to work. This change directly impacts the following
4393 powerpc bdm protocol
4395 Unless there is activity to revive these configurations, they will be
4396 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4398 * OBSOLETE configurations and files
4400 Configurations that have been declared obsolete in this release have
4401 been commented out. Unless there is activity to revive these
4402 configurations, the next release of GDB will have their sources
4403 permanently REMOVED.
4412 *** Changes in GDB 6.2.1:
4414 * MIPS `break main; run' gave an heuristic-fence-post warning
4416 When attempting to run even a simple program, a warning about
4417 heuristic-fence-post being hit would be reported. This problem has
4420 * MIPS IRIX 'long double' crashed GDB
4422 When examining a long double variable, GDB would get a segmentation
4423 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4424 IRIX long double values).
4428 A bug in the VAX stack code was causing problems with the "next"
4429 command. This problem has been fixed.
4431 *** Changes in GDB 6.2:
4433 * Fix for ``many threads''
4435 On GNU/Linux systems that use the NPTL threads library, a program
4436 rapidly creating and deleting threads would confuse GDB leading to the
4439 ptrace: No such process.
4440 thread_db_get_info: cannot get thread info: generic error
4442 This problem has been fixed.
4444 * "-async" and "-noasync" options removed.
4446 Support for the broken "-noasync" option has been removed (it caused
4449 * New ``start'' command.
4451 This command runs the program until the begining of the main procedure.
4453 * New BSD Kernel Data Access Library (libkvm) interface
4455 Using ``target kvm'' it is now possible to debug kernel core dumps and
4456 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4457 platforms. Currently supported (native-only) configurations are:
4459 FreeBSD/amd64 x86_64-*-freebsd*
4460 FreeBSD/i386 i?86-*-freebsd*
4461 NetBSD/i386 i?86-*-netbsd*
4462 NetBSD/m68k m68*-*-netbsd*
4463 NetBSD/sparc sparc-*-netbsd*
4464 OpenBSD/amd64 x86_64-*-openbsd*
4465 OpenBSD/i386 i?86-*-openbsd*
4466 OpenBSD/m68k m68*-openbsd*
4467 OpenBSD/sparc sparc-*-openbsd*
4469 * Signal trampoline code overhauled
4471 Many generic problems with GDB's signal handling code have been fixed.
4472 These include: backtraces through non-contiguous stacks; recognition
4473 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4474 call; backtrace through a signal trampoline; step into and out of
4475 signal handlers; and single-stepping in the signal trampoline.
4477 Please note that kernel bugs are a limiting factor here. These
4478 features have been shown to work on an s390 GNU/Linux system that
4479 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4481 * Cygwin support for DWARF 2 added.
4483 * New native configurations
4485 GNU/Linux/hppa hppa*-*-linux*
4486 OpenBSD/hppa hppa*-*-openbsd*
4487 OpenBSD/m68k m68*-*-openbsd*
4488 OpenBSD/m88k m88*-*-openbsd*
4489 OpenBSD/powerpc powerpc-*-openbsd*
4490 NetBSD/vax vax-*-netbsd*
4491 OpenBSD/vax vax-*-openbsd*
4493 * END-OF-LIFE frame compatibility module
4495 GDB's internal frame infrastructure has been completely rewritten.
4496 The new infrastructure making it possible to support key new features
4497 including DWARF 2 Call Frame Information. To aid in the task of
4498 migrating old configurations to this new infrastructure, a
4499 compatibility module, that allowed old configurations to continue to
4500 work, was also included.
4502 GDB 6.2 will be the last release to include this frame compatibility
4503 module. This change directly impacts the following configurations:
4513 Unless there is activity to revive these configurations, they will be
4514 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4516 * REMOVED configurations and files
4518 Sun 3, running SunOS 3 m68*-*-sunos3*
4519 Sun 3, running SunOS 4 m68*-*-sunos4*
4520 Sun 2, running SunOS 3 m68000-*-sunos3*
4521 Sun 2, running SunOS 4 m68000-*-sunos4*
4522 Motorola 680x0 running LynxOS m68*-*-lynxos*
4523 AT&T 3b1/Unix pc m68*-att-*
4524 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4525 decstation mips-dec-* mips-little-*
4526 riscos mips-*-riscos* mips-*-sysv*
4527 sonymips mips-sony-*
4528 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4530 *** Changes in GDB 6.1.1:
4532 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4534 The TUI (Text-mode User Interface) is now built as part of a default
4535 GDB configuration. It is enabled by either selecting the TUI with the
4536 command line option "-i=tui" or by running the separate "gdbtui"
4537 program. For more information on the TUI, see the manual "Debugging
4540 * Pending breakpoint support (also included in GDB 6.1)
4542 Support has been added to allow you to specify breakpoints in shared
4543 libraries that have not yet been loaded. If a breakpoint location
4544 cannot be found, and the "breakpoint pending" option is set to auto,
4545 GDB queries you if you wish to make the breakpoint pending on a future
4546 shared-library load. If and when GDB resolves the breakpoint symbol,
4547 the pending breakpoint is removed as one or more regular breakpoints
4550 Pending breakpoints are very useful for GCJ Java debugging.
4552 * Fixed ISO-C build problems
4554 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4555 non ISO-C code that stopped them being built using a more strict ISO-C
4556 compiler (e.g., IBM's C compiler).
4558 * Fixed build problem on IRIX 5
4560 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4561 wasn't able to compile compile on an IRIX 5 system.
4563 * Added execute permission to gdb/gdbserver/configure
4565 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4566 permission. This bug would cause configure to fail on a number of
4567 systems (Solaris, IRIX). Ref: server/519.
4569 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4571 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4572 has been updated to use constant array sizes.
4574 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4576 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4577 its generated DWARF Call Frame Info. This encoding was causing GDB to
4578 panic, that panic has been fixed. Ref: gdb/1628.
4580 * Fixed a problem when examining parameters in shared library code.
4582 When examining parameters in optimized shared library code generated
4583 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4584 not available''. GDB now correctly displays the variable's value.
4586 *** Changes in GDB 6.1:
4588 * Removed --with-mmalloc
4590 Support for the mmalloc memory manager has been removed, as it
4591 conflicted with the internal gdb byte cache.
4593 * Changes in AMD64 configurations
4595 The AMD64 target now includes the %cs and %ss registers. As a result
4596 the AMD64 remote protocol has changed; this affects the floating-point
4597 and SSE registers. If you rely on those registers for your debugging,
4598 you should upgrade gdbserver on the remote side.
4600 * Revised SPARC target
4602 The SPARC target has been completely revised, incorporating the
4603 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4604 support for LynxOS and SunOS 4 has been dropped. Calling functions
4605 from within GDB on operating systems with a non-executable stack
4606 (Solaris, OpenBSD) now works.
4610 GDB has a new C++ demangler which does a better job on the mangled
4611 names generated by current versions of g++. It also runs faster, so
4612 with this and other changes gdb should now start faster on large C++
4615 * DWARF 2 Location Expressions
4617 GDB support for location expressions has been extended to support function
4618 arguments and frame bases. Older versions of GDB could crash when they
4621 * C++ nested types and namespaces
4623 GDB's support for nested types and namespaces in C++ has been
4624 improved, especially if you use the DWARF 2 debugging format. (This
4625 is the default for recent versions of GCC on most platforms.)
4626 Specifically, if you have a class "Inner" defined within a class or
4627 namespace "Outer", then GDB realizes that the class's name is
4628 "Outer::Inner", not simply "Inner". This should greatly reduce the
4629 frequency of complaints about not finding RTTI symbols. In addition,
4630 if you are stopped at inside of a function defined within a namespace,
4631 GDB modifies its name lookup accordingly.
4633 * New native configurations
4635 NetBSD/amd64 x86_64-*-netbsd*
4636 OpenBSD/amd64 x86_64-*-openbsd*
4637 OpenBSD/alpha alpha*-*-openbsd*
4638 OpenBSD/sparc sparc-*-openbsd*
4639 OpenBSD/sparc64 sparc64-*-openbsd*
4641 * New debugging protocols
4643 M32R with SDI protocol m32r-*-elf*
4645 * "set prompt-escape-char" command deleted.
4647 The command "set prompt-escape-char" has been deleted. This command,
4648 and its very obscure effet on GDB's prompt, was never documented,
4649 tested, nor mentioned in the NEWS file.
4651 * OBSOLETE configurations and files
4653 Configurations that have been declared obsolete in this release have
4654 been commented out. Unless there is activity to revive these
4655 configurations, the next release of GDB will have their sources
4656 permanently REMOVED.
4658 Sun 3, running SunOS 3 m68*-*-sunos3*
4659 Sun 3, running SunOS 4 m68*-*-sunos4*
4660 Sun 2, running SunOS 3 m68000-*-sunos3*
4661 Sun 2, running SunOS 4 m68000-*-sunos4*
4662 Motorola 680x0 running LynxOS m68*-*-lynxos*
4663 AT&T 3b1/Unix pc m68*-att-*
4664 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4665 decstation mips-dec-* mips-little-*
4666 riscos mips-*-riscos* mips-*-sysv*
4667 sonymips mips-sony-*
4668 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4670 * REMOVED configurations and files
4672 SGI Irix-4.x mips-sgi-irix4 or iris4
4673 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4674 Z8000 simulator z8k-zilog-none or z8ksim
4675 Matsushita MN10200 w/simulator mn10200-*-*
4676 H8/500 simulator h8500-hitachi-hms or h8500hms
4677 HP/PA running BSD hppa*-*-bsd*
4678 HP/PA running OSF/1 hppa*-*-osf*
4679 HP/PA Pro target hppa*-*-pro*
4680 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4681 386BSD i[3456]86-*-bsd*
4682 Sequent family i[3456]86-sequent-sysv4*
4683 i[3456]86-sequent-sysv*
4684 i[3456]86-sequent-bsd*
4685 SPARC running LynxOS sparc-*-lynxos*
4686 SPARC running SunOS 4 sparc-*-sunos4*
4687 Tsqware Sparclet sparclet-*-*
4688 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4690 *** Changes in GDB 6.0:
4694 Support for debugging the Objective-C programming language has been
4695 integrated into GDB.
4697 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4699 DWARF 2's Call Frame Information makes available compiler generated
4700 information that more exactly describes the program's run-time stack.
4701 By using this information, GDB is able to provide more robust stack
4704 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4705 have been updated to use a new backtrace mechanism which includes
4706 DWARF 2 CFI support.
4710 GDB's remote protocol has been extended to include support for hosted
4711 file I/O (where the remote target uses GDB's file system). See GDB's
4712 remote protocol documentation for details.
4714 * All targets using the new architecture framework.
4716 All of GDB's targets have been updated to use the new internal
4717 architecture framework. The way is now open for future GDB releases
4718 to include cross-architecture native debugging support (i386 on amd64,
4721 * GNU/Linux's Thread Local Storage (TLS)
4723 GDB now includes support for for the GNU/Linux implementation of
4724 per-thread variables.
4726 * GNU/Linux's Native POSIX Thread Library (NPTL)
4728 GDB's thread code has been updated to work with either the new
4729 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4731 * Separate debug info.
4733 GDB, in conjunction with BINUTILS, now supports a mechanism for
4734 automatically loading debug information from a separate file. Instead
4735 of shipping full debug and non-debug versions of system libraries,
4736 system integrators can now instead ship just the stripped libraries
4737 and optional debug files.
4739 * DWARF 2 Location Expressions
4741 DWARF 2 Location Expressions allow the compiler to more completely
4742 describe the location of variables (even in optimized code) to the
4745 GDB now includes preliminary support for location expressions (support
4746 for DW_OP_piece is still missing).
4750 A number of long standing bugs that caused GDB to die while starting a
4751 Java application have been fixed. GDB's Java support is now
4752 considered "useable".
4754 * GNU/Linux support for fork, vfork, and exec.
4756 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4757 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4760 * GDB supports logging output to a file
4762 There are two new commands, "set logging" and "show logging", which can be
4763 used to capture GDB's output to a file.
4765 * The meaning of "detach" has changed for gdbserver
4767 The "detach" command will now resume the application, as documented. To
4768 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4771 * d10v, m68hc11 `regs' command deprecated
4773 The `info registers' command has been updated so that it displays the
4774 registers using a format identical to the old `regs' command.
4778 A new command, "maint set profile on/off", has been added. This command can
4779 be used to enable or disable profiling while running GDB, to profile a
4780 session or a set of commands. In addition there is a new configure switch,
4781 "--enable-profiling", which will cause GDB to be compiled with profiling
4782 data, for more informative profiling results.
4784 * Default MI syntax changed to "mi2".
4786 The default MI (machine interface) syntax, enabled by the command line
4787 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4788 "mi1", can be enabled by specifying the option "-i=mi1".
4790 Support for the original "mi0" syntax (included in GDB 5.0) has been
4793 Fix for gdb/192: removed extraneous space when displaying frame level.
4794 Fix for gdb/672: update changelist is now output in mi list format.
4795 Fix for gdb/702: a -var-assign that updates the value now shows up
4796 in a subsequent -var-update.
4798 * New native configurations.
4800 FreeBSD/amd64 x86_64-*-freebsd*
4802 * Multi-arched targets.
4804 HP/PA HPUX11 hppa*-*-hpux*
4805 Renesas M32R/D w/simulator m32r-*-elf*
4807 * OBSOLETE configurations and files
4809 Configurations that have been declared obsolete in this release have
4810 been commented out. Unless there is activity to revive these
4811 configurations, the next release of GDB will have their sources
4812 permanently REMOVED.
4814 Z8000 simulator z8k-zilog-none or z8ksim
4815 Matsushita MN10200 w/simulator mn10200-*-*
4816 H8/500 simulator h8500-hitachi-hms or h8500hms
4817 HP/PA running BSD hppa*-*-bsd*
4818 HP/PA running OSF/1 hppa*-*-osf*
4819 HP/PA Pro target hppa*-*-pro*
4820 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4821 Sequent family i[3456]86-sequent-sysv4*
4822 i[3456]86-sequent-sysv*
4823 i[3456]86-sequent-bsd*
4824 Tsqware Sparclet sparclet-*-*
4825 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4827 * REMOVED configurations and files
4830 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4831 IBM AIX PS/2 i[3456]86-*-aix
4832 i386 running Mach 3.0 i[3456]86-*-mach3*
4833 i386 running Mach i[3456]86-*-mach*
4834 i386 running OSF/1 i[3456]86-*osf1mk*
4835 HP/Apollo 68k Family m68*-apollo*-sysv*,
4837 m68*-hp-bsd*, m68*-hp-hpux*
4838 Argonaut Risc Chip (ARC) arc-*-*
4839 Mitsubishi D30V d30v-*-*
4840 Fujitsu FR30 fr30-*-elf*
4841 OS/9000 i[34]86-*-os9k
4842 I960 with MON960 i960-*-coff
4844 * MIPS $fp behavior changed
4846 The convenience variable $fp, for the MIPS, now consistently returns
4847 the address of the current frame's base. Previously, depending on the
4848 context, $fp could refer to either $sp or the current frame's base
4849 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4850 The GNU Source-Level Debugger''.
4852 *** Changes in GDB 5.3:
4854 * GNU/Linux shared library multi-threaded performance improved.
4856 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4857 `/proc', in preference to `ptrace' for memory reads. This may result
4858 in an improvement in the start-up time of multi-threaded, shared
4859 library applications when run under GDB. One GDB user writes: ``loads
4860 shared libs like mad''.
4862 * ``gdbserver'' now supports multi-threaded applications on some targets
4864 Support for debugging multi-threaded applications which use
4865 the GNU/Linux LinuxThreads package has been added for
4866 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4867 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4869 * GDB now supports C/C++ preprocessor macros.
4871 GDB now expands preprocessor macro invocations in C/C++ expressions,
4872 and provides various commands for showing macro definitions and how
4875 The new command `macro expand EXPRESSION' expands any macro
4876 invocations in expression, and shows the result.
4878 The new command `show macro MACRO-NAME' shows the definition of the
4879 macro named MACRO-NAME, and where it was defined.
4881 Most compilers don't include information about macros in the debugging
4882 information by default. In GCC 3.1, for example, you need to compile
4883 your program with the options `-gdwarf-2 -g3'. If the macro
4884 information is present in the executable, GDB will read it.
4886 * Multi-arched targets.
4888 DEC Alpha (partial) alpha*-*-*
4889 DEC VAX (partial) vax-*-*
4891 National Semiconductor NS32000 (partial) ns32k-*-*
4892 Motorola 68000 (partial) m68k-*-*
4893 Motorola MCORE mcore-*-*
4897 Fujitsu FRV architecture added by Red Hat frv*-*-*
4900 * New native configurations
4902 Alpha NetBSD alpha*-*-netbsd*
4903 SH NetBSD sh*-*-netbsdelf*
4904 MIPS NetBSD mips*-*-netbsd*
4905 UltraSPARC NetBSD sparc64-*-netbsd*
4907 * OBSOLETE configurations and files
4909 Configurations that have been declared obsolete in this release have
4910 been commented out. Unless there is activity to revive these
4911 configurations, the next release of GDB will have their sources
4912 permanently REMOVED.
4914 Mitsubishi D30V d30v-*-*
4915 OS/9000 i[34]86-*-os9k
4916 IBM AIX PS/2 i[3456]86-*-aix
4917 Fujitsu FR30 fr30-*-elf*
4918 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4919 Argonaut Risc Chip (ARC) arc-*-*
4920 i386 running Mach 3.0 i[3456]86-*-mach3*
4921 i386 running Mach i[3456]86-*-mach*
4922 i386 running OSF/1 i[3456]86-*osf1mk*
4923 HP/Apollo 68k Family m68*-apollo*-sysv*,
4925 m68*-hp-bsd*, m68*-hp-hpux*
4926 I960 with MON960 i960-*-coff
4928 * OBSOLETE languages
4930 CHILL, a Pascal like language used by telecommunications companies.
4932 * REMOVED configurations and files
4934 AMD 29k family via UDI a29k-amd-udi, udi29k
4935 A29K VxWorks a29k-*-vxworks
4936 AMD 29000 embedded, using EBMON a29k-none-none
4937 AMD 29000 embedded with COFF a29k-none-coff
4938 AMD 29000 embedded with a.out a29k-none-aout
4940 testsuite/gdb.hp/gdb.threads-hp/ directory
4942 * New command "set max-user-call-depth <nnn>"
4944 This command allows the user to limit the call depth of user-defined
4945 commands. The default is 1024.
4947 * Changes in FreeBSD/i386 native debugging.
4949 Support for the "generate-core-file" has been added.
4951 * New commands "dump", "append", and "restore".
4953 These commands allow data to be copied from target memory
4954 to a bfd-format or binary file (dump and append), and back
4955 from a file into memory (restore).
4957 * Improved "next/step" support on multi-processor Alpha Tru64.
4959 The previous single-step mechanism could cause unpredictable problems,
4960 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4961 of a software single-step mechanism prevents this.
4963 *** Changes in GDB 5.2.1:
4971 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4972 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4973 Fix, by Joel Brobecker imported from mainline.
4975 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4976 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4977 Fix, by Fred Fish, imported from mainline.
4979 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4980 Surprisingly enough, it works now.
4981 By Michal Ludvig, imported from mainline.
4983 i386 hardware watchpoint support:
4984 avoid misses on second run for some targets.
4985 By Pierre Muller, imported from mainline.
4987 *** Changes in GDB 5.2:
4989 * New command "set trust-readonly-sections on[off]".
4991 This command is a hint that tells gdb that read-only sections
4992 really are read-only (ie. that their contents will not change).
4993 In this mode, gdb will go to the object file rather than the
4994 target to read memory from read-only sections (such as ".text").
4995 This can be a significant performance improvement on some
4996 (notably embedded) targets.
4998 * New command "generate-core-file" (or "gcore").
5000 This new gdb command allows the user to drop a core file of the child
5001 process state at any time. So far it's been implemented only for
5002 GNU/Linux and Solaris, but should be relatively easily ported to other
5003 hosts. Argument is core file name (defaults to core.<pid>).
5005 * New command line option
5007 GDB now accepts --pid or -p followed by a process id.
5009 * Change in command line behavior -- corefiles vs. process ids.
5011 There is a subtle behavior in the way in which GDB handles
5012 command line arguments. The first non-flag argument is always
5013 a program to debug, but the second non-flag argument may either
5014 be a corefile or a process id. Previously, GDB would attempt to
5015 open the second argument as a corefile, and if that failed, would
5016 issue a superfluous error message and then attempt to attach it as
5017 a process. Now, if the second argument begins with a non-digit,
5018 it will be treated as a corefile. If it begins with a digit,
5019 GDB will attempt to attach it as a process, and if no such process
5020 is found, will then attempt to open it as a corefile.
5022 * Changes in ARM configurations.
5024 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5025 configuration is fully multi-arch.
5027 * New native configurations
5029 ARM NetBSD arm*-*-netbsd*
5030 x86 OpenBSD i[3456]86-*-openbsd*
5031 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5032 Sparc64 running FreeBSD sparc64-*-freebsd*
5036 Sanyo XStormy16 xstormy16-elf
5038 * OBSOLETE configurations and files
5040 Configurations that have been declared obsolete in this release have
5041 been commented out. Unless there is activity to revive these
5042 configurations, the next release of GDB will have their sources
5043 permanently REMOVED.
5045 AMD 29k family via UDI a29k-amd-udi, udi29k
5046 A29K VxWorks a29k-*-vxworks
5047 AMD 29000 embedded, using EBMON a29k-none-none
5048 AMD 29000 embedded with COFF a29k-none-coff
5049 AMD 29000 embedded with a.out a29k-none-aout
5051 testsuite/gdb.hp/gdb.threads-hp/ directory
5053 * REMOVED configurations and files
5055 TI TMS320C80 tic80-*-*
5057 PowerPC Solaris powerpcle-*-solaris*
5058 PowerPC Windows NT powerpcle-*-cygwin32
5059 PowerPC Netware powerpc-*-netware*
5060 Harris/CXUX m88k m88*-harris-cxux*
5061 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5062 ns32k-utek-sysv* ns32k-utek-*
5063 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5064 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5065 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5066 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5067 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5069 * Changes to command line processing
5071 The new `--args' feature can be used to specify command-line arguments
5072 for the inferior from gdb's command line.
5074 * Changes to key bindings
5076 There is a new `operate-and-get-next' function bound to `C-o'.
5078 *** Changes in GDB 5.1.1
5080 Fix compile problem on DJGPP.
5082 Fix a problem with floating-point registers on the i386 being
5085 Fix to stop GDB crashing on .debug_str debug info.
5087 Numerous documentation fixes.
5089 Numerous testsuite fixes.
5091 *** Changes in GDB 5.1:
5093 * New native configurations
5095 Alpha FreeBSD alpha*-*-freebsd*
5096 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5097 MIPS GNU/Linux mips*-*-linux*
5098 MIPS SGI Irix 6.x mips*-sgi-irix6*
5099 ia64 AIX ia64-*-aix*
5100 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5104 Motorola 68HC11 and 68HC12 m68hc11-elf
5106 UltraSparc running GNU/Linux sparc64-*-linux*
5108 * OBSOLETE configurations and files
5110 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5111 Harris/CXUX m88k m88*-harris-cxux*
5112 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5113 ns32k-utek-sysv* ns32k-utek-*
5114 TI TMS320C80 tic80-*-*
5116 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5117 PowerPC Solaris powerpcle-*-solaris*
5118 PowerPC Windows NT powerpcle-*-cygwin32
5119 PowerPC Netware powerpc-*-netware*
5120 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5121 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5122 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5123 Apple Macintosh (MPW) host N/A
5125 stuff.c (Program to stuff files into a specially prepared space in kdb)
5126 kdb-start.c (Main loop for the standalone kernel debugger)
5128 Configurations that have been declared obsolete in this release have
5129 been commented out. Unless there is activity to revive these
5130 configurations, the next release of GDB will have their sources
5131 permanently REMOVED.
5133 * REMOVED configurations and files
5135 Altos 3068 m68*-altos-*
5136 Convex c1-*-*, c2-*-*
5138 ARM RISCix arm-*-* (as host)
5142 * GDB has been converted to ISO C.
5144 GDB's source code has been converted to ISO C. In particular, the
5145 sources are fully protoized, and rely on standard headers being
5150 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5152 * The MI enabled by default.
5154 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5155 revised and enabled by default. Packages which use GDB as a debugging
5156 engine behind a UI or another front end are encouraged to switch to
5157 using the GDB/MI interface, instead of the old annotations interface
5158 which is now deprecated.
5160 * Support for debugging Pascal programs.
5162 GDB now includes support for debugging Pascal programs. The following
5163 main features are supported:
5165 - Pascal-specific data types such as sets;
5167 - automatic recognition of Pascal sources based on file-name
5170 - Pascal-style display of data types, variables, and functions;
5172 - a Pascal expression parser.
5174 However, some important features are not yet supported.
5176 - Pascal string operations are not supported at all;
5178 - there are some problems with boolean types;
5180 - Pascal type hexadecimal constants are not supported
5181 because they conflict with the internal variables format;
5183 - support for Pascal objects and classes is not full yet;
5185 - unlike Pascal, GDB is case-sensitive for symbol names.
5187 * Changes in completion.
5189 Commands such as `shell', `run' and `set args', which pass arguments
5190 to inferior programs, now complete on file names, similar to what
5191 users expect at the shell prompt.
5193 Commands which accept locations, such as `disassemble', `print',
5194 `breakpoint', `until', etc. now complete on filenames as well as
5195 program symbols. Thus, if you type "break foob TAB", and the source
5196 files linked into the programs include `foobar.c', that file name will
5197 be one of the candidates for completion. However, file names are not
5198 considered for completion after you typed a colon that delimits a file
5199 name from a name of a function in that file, as in "break foo.c:bar".
5201 `set demangle-style' completes on available demangling styles.
5203 * New platform-independent commands:
5205 It is now possible to define a post-hook for a command as well as a
5206 hook that runs before the command. For more details, see the
5207 documentation of `hookpost' in the GDB manual.
5209 * Changes in GNU/Linux native debugging.
5211 Support for debugging multi-threaded programs has been completely
5212 revised for all platforms except m68k and sparc. You can now debug as
5213 many threads as your system allows you to have.
5215 Attach/detach is supported for multi-threaded programs.
5217 Support for SSE registers was added for x86. This doesn't work for
5218 multi-threaded programs though.
5220 * Changes in MIPS configurations.
5222 Multi-arch support is enabled for all MIPS configurations.
5224 GDB can now be built as native debugger on SGI Irix 6.x systems for
5225 debugging n32 executables. (Debugging 64-bit executables is not yet
5228 * Unified support for hardware watchpoints in all x86 configurations.
5230 Most (if not all) native x86 configurations support hardware-assisted
5231 breakpoints and watchpoints in a unified manner. This support
5232 implements debug register sharing between watchpoints, which allows to
5233 put a virtually infinite number of watchpoints on the same address,
5234 and also supports watching regions up to 16 bytes with several debug
5237 The new maintenance command `maintenance show-debug-regs' toggles
5238 debugging print-outs in functions that insert, remove, and test
5239 watchpoints and hardware breakpoints.
5241 * Changes in the DJGPP native configuration.
5243 New command ``info dos sysinfo'' displays assorted information about
5244 the CPU, OS, memory, and DPMI server.
5246 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5247 display information about segment descriptors stored in GDT, LDT, and
5250 New commands ``info dos pde'' and ``info dos pte'' display entries
5251 from Page Directory and Page Tables (for now works with CWSDPMI only).
5252 New command ``info dos address-pte'' displays the Page Table entry for
5253 a given linear address.
5255 GDB can now pass command lines longer than 126 characters to the
5256 program being debugged (requires an update to the libdbg.a library
5257 which is part of the DJGPP development kit).
5259 DWARF2 debug info is now supported.
5261 It is now possible to `step' and `next' through calls to `longjmp'.
5263 * Changes in documentation.
5265 All GDB documentation was converted to GFDL, the GNU Free
5266 Documentation License.
5268 Tracepoints-related commands are now fully documented in the GDB
5271 TUI, the Text-mode User Interface, is now documented in the manual.
5273 Tracepoints-related commands are now fully documented in the GDB
5276 The "GDB Internals" manual now has an index. It also includes
5277 documentation of `ui_out' functions, GDB coding standards, x86
5278 hardware watchpoints, and memory region attributes.
5280 * GDB's version number moved to ``version.in''
5282 The Makefile variable VERSION has been replaced by the file
5283 ``version.in''. People creating GDB distributions should update the
5284 contents of this file.
5288 GUD support is now a standard part of the EMACS distribution.
5290 *** Changes in GDB 5.0:
5292 * Improved support for debugging FP programs on x86 targets
5294 Unified and much-improved support for debugging floating-point
5295 programs on all x86 targets. In particular, ``info float'' now
5296 displays the FP registers in the same format on all x86 targets, with
5297 greater level of detail.
5299 * Improvements and bugfixes in hardware-assisted watchpoints
5301 It is now possible to watch array elements, struct members, and
5302 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5303 on x86 targets no longer erroneously trigger when the address is
5306 * Improvements in the native DJGPP version of GDB
5308 The distribution now includes all the scripts and auxiliary files
5309 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5310 machines ``out of the box''.
5312 The DJGPP version can now debug programs that use signals. It is
5313 possible to catch signals that happened in the debuggee, deliver
5314 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5315 would kill the program being debugged.) Programs that hook hardware
5316 interrupts (keyboard, timer, etc.) can also be debugged.
5318 It is now possible to debug DJGPP programs that redirect their
5319 standard handles or switch them to raw (as opposed to cooked) mode, or
5320 even close them. The command ``run < foo > bar'' works as expected,
5321 and ``info terminal'' reports useful information about the debuggee's
5322 terminal, including raw/cooked mode, redirection, etc.
5324 The DJGPP version now uses termios functions for console I/O, which
5325 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5328 DOS-style file names with drive letters are now fully supported by
5331 It is now possible to debug DJGPP programs that switch their working
5332 directory. It is also possible to rerun the debuggee any number of
5333 times without restarting GDB; thus, you can use the same setup,
5334 breakpoints, etc. for many debugging sessions.
5336 * New native configurations
5338 ARM GNU/Linux arm*-*-linux*
5339 PowerPC GNU/Linux powerpc-*-linux*
5343 Motorola MCore mcore-*-*
5344 x86 VxWorks i[3456]86-*-vxworks*
5345 PowerPC VxWorks powerpc-*-vxworks*
5346 TI TMS320C80 tic80-*-*
5348 * OBSOLETE configurations
5350 Altos 3068 m68*-altos-*
5351 Convex c1-*-*, c2-*-*
5353 ARM RISCix arm-*-* (as host)
5356 Configurations that have been declared obsolete will be commented out,
5357 but the code will be left in place. If there is no activity to revive
5358 these configurations before the next release of GDB, the sources will
5359 be permanently REMOVED.
5361 * Gould support removed
5363 Support for the Gould PowerNode and NP1 has been removed.
5365 * New features for SVR4
5367 On SVR4 native platforms (such as Solaris), if you attach to a process
5368 without first loading a symbol file, GDB will now attempt to locate and
5369 load symbols from the running process's executable file.
5371 * Many C++ enhancements
5373 C++ support has been greatly improved. Overload resolution now works properly
5374 in almost all cases. RTTI support is on the way.
5376 * Remote targets can connect to a sub-program
5378 A popen(3) style serial-device has been added. This device starts a
5379 sub-process (such as a stand-alone simulator) and then communicates
5380 with that. The sub-program to run is specified using the syntax
5381 ``|<program> <args>'' vis:
5383 (gdb) set remotedebug 1
5384 (gdb) target extended-remote |mn10300-elf-sim program-args
5386 * MIPS 64 remote protocol
5388 A long standing bug in the mips64 remote protocol where by GDB
5389 expected certain 32 bit registers (ex SR) to be transfered as 32
5390 instead of 64 bits has been fixed.
5392 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5393 added to provide backward compatibility with older versions of GDB.
5395 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5397 The command ``set remotebinarydownload'' command has been replaced by
5398 ``set remote X-packet''. Other commands in ``set remote'' family
5399 include ``set remote P-packet''.
5401 * Breakpoint commands accept ranges.
5403 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5404 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5405 ``tracepoint passcount'' also accepts a range of tracepoints.
5407 * ``apropos'' command added.
5409 The ``apropos'' command searches through command names and
5410 documentation strings, printing out matches, making it much easier to
5411 try to find a command that does what you are looking for.
5415 A new machine oriented interface (MI) has been added to GDB. This
5416 interface is designed for debug environments running GDB as a separate
5417 process. This is part of the long term libGDB project. See the
5418 "GDB/MI" chapter of the GDB manual for further information. It can be
5419 enabled by configuring with:
5421 .../configure --enable-gdbmi
5423 *** Changes in GDB-4.18:
5425 * New native configurations
5427 HP-UX 10.20 hppa*-*-hpux10.20
5428 HP-UX 11.x hppa*-*-hpux11.0*
5429 M68K GNU/Linux m68*-*-linux*
5433 Fujitsu FR30 fr30-*-elf*
5434 Intel StrongARM strongarm-*-*
5435 Mitsubishi D30V d30v-*-*
5437 * OBSOLETE configurations
5439 Gould PowerNode, NP1 np1-*-*, pn-*-*
5441 Configurations that have been declared obsolete will be commented out,
5442 but the code will be left in place. If there is no activity to revive
5443 these configurations before the next release of GDB, the sources will
5444 be permanently REMOVED.
5448 As a compatibility experiment, GDB's source files buildsym.h and
5449 buildsym.c have been converted to pure standard C, no longer
5450 containing any K&R compatibility code. We believe that all systems in
5451 use today either come with a standard C compiler, or have a GCC port
5452 available. If this is not true, please report the affected
5453 configuration to bug-gdb@gnu.org immediately. See the README file for
5454 information about getting a standard C compiler if you don't have one
5459 GDB now uses readline 2.2.
5461 * set extension-language
5463 You can now control the mapping between filename extensions and source
5464 languages by using the `set extension-language' command. For instance,
5465 you can ask GDB to treat .c files as C++ by saying
5466 set extension-language .c c++
5467 The command `info extensions' lists all of the recognized extensions
5468 and their associated languages.
5470 * Setting processor type for PowerPC and RS/6000
5472 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5473 you can use the `set processor' command to specify what variant of the
5474 PowerPC family you are debugging. The command
5478 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5479 following PowerPC and RS6000 variants:
5481 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5482 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5484 403GC IBM PowerPC 403GC
5485 505 Motorola PowerPC 505
5486 860 Motorola PowerPC 860 or 850
5487 601 Motorola PowerPC 601
5488 602 Motorola PowerPC 602
5489 603 Motorola/IBM PowerPC 603 or 603e
5490 604 Motorola PowerPC 604 or 604e
5491 750 Motorola/IBM PowerPC 750 or 750
5493 At the moment, this command just tells GDB what to name the
5494 special-purpose processor registers. Since almost all the affected
5495 registers are inaccessible to user-level programs, this command is
5496 only useful for remote debugging in its present form.
5500 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5501 more extensive support for HP-UX. Added features include shared
5502 library support, kernel threads and hardware watchpoints for 11.00,
5503 support for HP's ANSI C and C++ compilers, and a compatibility mode
5504 for xdb and dbx commands.
5508 HP's donation includes the new concept of catchpoints, which is a
5509 generalization of the old catch command. On HP-UX, it is now possible
5510 to catch exec, fork, and vfork, as well as library loading.
5512 This means that the existing catch command has changed; its first
5513 argument now specifies the type of catch to be set up. See the
5514 output of "help catch" for a list of catchpoint types.
5516 * Debugging across forks
5518 On HP-UX, you can choose which process to debug when a fork() happens
5523 HP has donated a curses-based terminal user interface (TUI). To get
5524 it, build with --enable-tui. Although this can be enabled for any
5525 configuration, at present it only works for native HP debugging.
5527 * GDB remote protocol additions
5529 A new protocol packet 'X' that writes binary data is now available.
5530 Default behavior is to try 'X', then drop back to 'M' if the stub
5531 fails to respond. The settable variable `remotebinarydownload'
5532 allows explicit control over the use of 'X'.
5534 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5535 full 64-bit address. The command
5537 set remoteaddresssize 32
5539 can be used to revert to the old behaviour. For existing remote stubs
5540 the change should not be noticed, as the additional address information
5543 In order to assist in debugging stubs, you may use the maintenance
5544 command `packet' to send any text string to the stub. For instance,
5546 maint packet heythere
5548 sends the packet "$heythere#<checksum>". Note that it is very easy to
5549 disrupt a debugging session by sending the wrong packet at the wrong
5552 The compare-sections command allows you to compare section data on the
5553 target to what is in the executable file without uploading or
5554 downloading, by comparing CRC checksums.
5556 * Tracing can collect general expressions
5558 You may now collect general expressions at tracepoints. This requires
5559 further additions to the target-side stub; see tracepoint.c and
5560 doc/agentexpr.texi for further details.
5562 * mask-address variable for Mips
5564 For Mips targets, you may control the zeroing of the upper 32 bits of
5565 a 64-bit address by entering `set mask-address on'. This is mainly
5566 of interest to users of embedded R4xxx and R5xxx processors.
5568 * Higher serial baud rates
5570 GDB's serial code now allows you to specify baud rates 57600, 115200,
5571 230400, and 460800 baud. (Note that your host system may not be able
5572 to achieve all of these rates.)
5576 The i960 configuration now includes an initial implementation of a
5577 builtin simulator, contributed by Jim Wilson.
5580 *** Changes in GDB-4.17:
5582 * New native configurations
5584 Alpha GNU/Linux alpha*-*-linux*
5585 Unixware 2.x i[3456]86-unixware2*
5586 Irix 6.x mips*-sgi-irix6*
5587 PowerPC GNU/Linux powerpc-*-linux*
5588 PowerPC Solaris powerpcle-*-solaris*
5589 Sparc GNU/Linux sparc-*-linux*
5590 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5594 Argonaut Risc Chip (ARC) arc-*-*
5595 Hitachi H8/300S h8300*-*-*
5596 Matsushita MN10200 w/simulator mn10200-*-*
5597 Matsushita MN10300 w/simulator mn10300-*-*
5598 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5599 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5600 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5601 Mitsubishi D10V w/simulator d10v-*-*
5602 Mitsubishi M32R/D w/simulator m32r-*-elf*
5603 Tsqware Sparclet sparclet-*-*
5604 NEC V850 w/simulator v850-*-*
5606 * New debugging protocols
5608 ARM with RDI protocol arm*-*-*
5609 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5610 DDB and LSI variants of PMON protocol mips*-*-*
5611 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5612 PowerPC with SDS protocol powerpc{,le}-*-eabi
5613 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5617 All configurations can now understand and use the DWARF 2 debugging
5618 format. The choice is automatic, if the symbol file contains DWARF 2
5623 GDB now includes basic Java language support. This support is
5624 only useful with Java compilers that produce native machine code.
5626 * solib-absolute-prefix and solib-search-path
5628 For SunOS and SVR4 shared libraries, you may now set the prefix for
5629 loading absolute shared library symbol files, and the search path for
5630 locating non-absolute shared library symbol files.
5632 * Live range splitting
5634 GDB can now effectively debug code for which GCC has performed live
5635 range splitting as part of its optimization. See gdb/doc/LRS for
5636 more details on the expected format of the stabs information.
5640 GDB's support for the GNU Hurd, including thread debugging, has been
5641 updated to work with current versions of the Hurd.
5645 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5646 instruction set. ARM GDB automatically detects when Thumb
5647 instructions are in use, and adjusts disassembly and backtracing
5652 GDB's MIPS target configurations now handle the MIP16 16-bit
5657 GDB now includes support for overlays; if an executable has been
5658 linked such that multiple sections are based at the same address, GDB
5659 will decide which section to use for symbolic info. You can choose to
5660 control the decision manually, using overlay commands, or implement
5661 additional target-side support and use "overlay load-target" to bring
5662 in the overlay mapping. Do "help overlay" for more detail.
5666 The command "info symbol <address>" displays information about
5667 the symbol at the specified address.
5671 The standard remote protocol now includes an extension that allows
5672 asynchronous collection and display of trace data. This requires
5673 extensive support in the target-side debugging stub. Tracing mode
5674 includes a new interaction mode in GDB and new commands: see the
5675 file tracepoint.c for more details.
5679 Configurations for embedded MIPS now include a simulator contributed
5680 by Cygnus Solutions. The simulator supports the instruction sets
5681 of most MIPS variants.
5685 Sparc configurations may now include the ERC32 simulator contributed
5686 by the European Space Agency. The simulator is not built into
5687 Sparc targets by default; configure with --enable-sim to include it.
5691 For target configurations that may include multiple variants of a
5692 basic architecture (such as MIPS and SH), you may now set the
5693 architecture explicitly. "set arch" sets, "info arch" lists
5694 the possible architectures.
5696 *** Changes in GDB-4.16:
5698 * New native configurations
5700 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5701 M68K NetBSD m68k-*-netbsd*
5702 PowerPC AIX 4.x powerpc-*-aix*
5703 PowerPC MacOS powerpc-*-macos*
5704 PowerPC Windows NT powerpcle-*-cygwin32
5705 RS/6000 AIX 4.x rs6000-*-aix4*
5709 ARM with RDP protocol arm-*-*
5710 I960 with MON960 i960-*-coff
5711 MIPS VxWorks mips*-*-vxworks*
5712 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5713 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5715 Matra Sparclet sparclet-*-*
5719 The powerpc-eabi configuration now includes the PSIM simulator,
5720 contributed by Andrew Cagney, with assistance from Mike Meissner.
5721 PSIM is a very elaborate model of the PowerPC, including not only
5722 basic instruction set execution, but also details of execution unit
5723 performance and I/O hardware. See sim/ppc/README for more details.
5727 GDB now works with Solaris 2.5.
5729 * Windows 95/NT native
5731 GDB will now work as a native debugger on Windows 95 and Windows NT.
5732 To build it from source, you must use the "gnu-win32" environment,
5733 which uses a DLL to emulate enough of Unix to run the GNU tools.
5734 Further information, binaries, and sources are available at
5735 ftp.cygnus.com, under pub/gnu-win32.
5737 * dont-repeat command
5739 If a user-defined command includes the command `dont-repeat', then the
5740 command will not be repeated if the user just types return. This is
5741 useful if the command is time-consuming to run, so that accidental
5742 extra keystrokes don't run the same command many times.
5744 * Send break instead of ^C
5746 The standard remote protocol now includes an option to send a break
5747 rather than a ^C to the target in order to interrupt it. By default,
5748 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5750 * Remote protocol timeout
5752 The standard remote protocol includes a new variable `remotetimeout'
5753 that allows you to set the number of seconds before GDB gives up trying
5754 to read from the target. The default value is 2.
5756 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5758 By default GDB will automatically keep track of objects as they are
5759 loaded and unloaded by the dynamic linker. By using the command `set
5760 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5761 when shared library events occur, thus allowing you to set breakpoints
5762 in shared libraries which are explicitly loaded by the inferior.
5764 Note this feature does not work on hpux8. On hpux9 you must link
5765 /usr/lib/end.o into your program. This feature should work
5766 automatically on hpux10.
5768 * Irix 5.x hardware watchpoint support
5770 Irix 5 configurations now support the use of hardware watchpoints.
5772 * Mips protocol "SYN garbage limit"
5774 When debugging a Mips target using the `target mips' protocol, you
5775 may set the number of characters that GDB will ignore by setting
5776 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5777 every character. The default value is 1050.
5779 * Recording and replaying remote debug sessions
5781 If you set `remotelogfile' to the name of a file, gdb will write to it
5782 a recording of a remote debug session. This recording may then be
5783 replayed back to gdb using "gdbreplay". See gdbserver/README for
5784 details. This is useful when you have a problem with GDB while doing
5785 remote debugging; you can make a recording of the session and send it
5786 to someone else, who can then recreate the problem.
5788 * Speedups for remote debugging
5790 GDB includes speedups for downloading and stepping MIPS systems using
5791 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5792 and more efficient S-record downloading.
5794 * Memory use reductions and statistics collection
5796 GDB now uses less memory and reports statistics about memory usage.
5797 Try the `maint print statistics' command, for example.
5799 *** Changes in GDB-4.15:
5801 * Psymtabs for XCOFF
5803 The symbol reader for AIX GDB now uses partial symbol tables. This
5804 can greatly improve startup time, especially for large executables.
5806 * Remote targets use caching
5808 Remote targets now use a data cache to speed up communication with the
5809 remote side. The data cache could lead to incorrect results because
5810 it doesn't know about volatile variables, thus making it impossible to
5811 debug targets which use memory mapped I/O devices. `set remotecache
5812 off' turns the the data cache off.
5814 * Remote targets may have threads
5816 The standard remote protocol now includes support for multiple threads
5817 in the target system, using new protocol commands 'H' and 'T'. See
5818 gdb/remote.c for details.
5822 If GDB is configured with `--enable-netrom', then it will include
5823 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5824 acts as though it is a bank of ROM on the target board, but you can
5825 write into it over the network. GDB's support consists only of
5826 support for fast loading into the emulated ROM; to debug, you must use
5827 another protocol, such as standard remote protocol. The usual
5828 sequence is something like
5830 target nrom <netrom-hostname>
5832 target remote <netrom-hostname>:1235
5836 GDB now includes support for the Apple Macintosh, as a host only. It
5837 may be run as either an MPW tool or as a standalone application, and
5838 it can debug through the serial port. All the usual GDB commands are
5839 available, but to the target command, you must supply "serial" as the
5840 device type instead of "/dev/ttyXX". See mpw-README in the main
5841 directory for more information on how to build. The MPW configuration
5842 scripts */mpw-config.in support only a few targets, and only the
5843 mips-idt-ecoff target has been tested.
5847 GDB configuration now uses autoconf. This is not user-visible,
5848 but does simplify configuration and building.
5852 GDB now supports hpux10.
5854 *** Changes in GDB-4.14:
5856 * New native configurations
5858 x86 FreeBSD i[345]86-*-freebsd
5859 x86 NetBSD i[345]86-*-netbsd
5860 NS32k NetBSD ns32k-*-netbsd
5861 Sparc NetBSD sparc-*-netbsd
5865 A29K VxWorks a29k-*-vxworks
5866 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5867 CPU32 EST-300 emulator m68*-*-est*
5868 PowerPC ELF powerpc-*-elf
5871 * Alpha OSF/1 support for procfs
5873 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5874 possible to attach to running processes. As the mounting of the /proc
5875 filesystem is optional on the Alpha, GDB automatically determines
5876 the availability of /proc during startup. This can lead to problems
5877 if /proc is unmounted after GDB has been started.
5879 * Arguments to user-defined commands
5881 User commands may accept up to 10 arguments separated by whitespace.
5882 Arguments are accessed within the user command via $arg0..$arg9. A
5885 print $arg0 + $arg1 + $arg2
5887 To execute the command use:
5890 Defines the command "adder" which prints the sum of its three arguments.
5891 Note the arguments are text substitutions, so they may reference variables,
5892 use complex expressions, or even perform inferior function calls.
5894 * New `if' and `while' commands
5896 This makes it possible to write more sophisticated user-defined
5897 commands. Both commands take a single argument, which is the
5898 expression to evaluate, and must be followed by the commands to
5899 execute, one per line, if the expression is nonzero, the list being
5900 terminated by the word `end'. The `if' command list may include an
5901 `else' word, which causes the following commands to be executed only
5902 if the expression is zero.
5904 * Fortran source language mode
5906 GDB now includes partial support for Fortran 77. It will recognize
5907 Fortran programs and can evaluate a subset of Fortran expressions, but
5908 variables and functions may not be handled correctly. GDB will work
5909 with G77, but does not yet know much about symbols emitted by other
5912 * Better HPUX support
5914 Most debugging facilities now work on dynamic executables for HPPAs
5915 running hpux9 or later. You can attach to running dynamically linked
5916 processes, but by default the dynamic libraries will be read-only, so
5917 for instance you won't be able to put breakpoints in them. To change
5918 that behavior do the following before running the program:
5924 This will cause the libraries to be mapped private and read-write.
5925 To revert to the normal behavior, do this:
5931 You cannot set breakpoints or examine data in the library until after
5932 the library is loaded if the function/data symbols do not have
5935 GDB can now also read debug symbols produced by the HP C compiler on
5936 HPPAs (sorry, no C++, Fortran or 68k support).
5938 * Target byte order now dynamically selectable
5940 You can choose which byte order to use with a target system, via the
5941 commands "set endian big" and "set endian little", and you can see the
5942 current setting by using "show endian". You can also give the command
5943 "set endian auto", in which case GDB will use the byte order
5944 associated with the executable. Currently, only embedded MIPS
5945 configurations support dynamic selection of target byte order.
5947 * New DOS host serial code
5949 This version uses DPMI interrupts to handle buffered I/O, so you
5950 no longer need to run asynctsr when debugging boards connected to
5953 *** Changes in GDB-4.13:
5955 * New "complete" command
5957 This lists all the possible completions for the rest of the line, if it
5958 were to be given as a command itself. This is intended for use by emacs.
5960 * Trailing space optional in prompt
5962 "set prompt" no longer adds a space for you after the prompt you set. This
5963 allows you to set a prompt which ends in a space or one that does not.
5965 * Breakpoint hit counts
5967 "info break" now displays a count of the number of times the breakpoint
5968 has been hit. This is especially useful in conjunction with "ignore"; you
5969 can ignore a large number of breakpoint hits, look at the breakpoint info
5970 to see how many times the breakpoint was hit, then run again, ignoring one
5971 less than that number, and this will get you quickly to the last hit of
5974 * Ability to stop printing at NULL character
5976 "set print null-stop" will cause GDB to stop printing the characters of
5977 an array when the first NULL is encountered. This is useful when large
5978 arrays actually contain only short strings.
5980 * Shared library breakpoints
5982 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5983 breakpoints in shared libraries before the executable is run.
5985 * Hardware watchpoints
5987 There is a new hardware breakpoint for the watch command for sparclite
5988 targets. See gdb/sparclite/hw_breakpoint.note.
5990 Hardware watchpoints are also now supported under GNU/Linux.
5994 Annotations have been added. These are for use with graphical interfaces,
5995 and are still experimental. Currently only gdba.el uses these.
5997 * Improved Irix 5 support
5999 GDB now works properly with Irix 5.2.
6001 * Improved HPPA support
6003 GDB now works properly with the latest GCC and GAS.
6005 * New native configurations
6007 Sequent PTX4 i[34]86-sequent-ptx4
6008 HPPA running OSF/1 hppa*-*-osf*
6009 Atari TT running SVR4 m68*-*-sysv4*
6010 RS/6000 LynxOS rs6000-*-lynxos*
6014 OS/9000 i[34]86-*-os9k
6015 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6018 * Hitachi SH7000 and E7000-PC ICE support
6020 There is now support for communicating with the Hitachi E7000-PC ICE.
6021 This is available automatically when GDB is configured for the SH.
6025 As usual, a variety of small fixes and improvements, both generic
6026 and configuration-specific. See the ChangeLog for more detail.
6028 *** Changes in GDB-4.12:
6030 * Irix 5 is now supported
6034 GDB-4.12 on the HPPA has a number of changes which make it unable
6035 to debug the output from the currently released versions of GCC and
6036 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6037 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6038 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6041 *** Changes in GDB-4.11:
6043 * User visible changes:
6047 The "set remotedebug" option is now consistent between the mips remote
6048 target, remote targets using the gdb-specific protocol, UDI (AMD's
6049 debug protocol for the 29k) and the 88k bug monitor. It is now an
6050 integer specifying a debug level (normally 0 or 1, but 2 means more
6051 debugging info for the mips target).
6053 * DEC Alpha native support
6055 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6056 debug info, but GDB works fairly well with the DEC compiler and should
6057 work with a future GCC release. See the README file for a few
6058 Alpha-specific notes.
6060 * Preliminary thread implementation
6062 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6064 * LynxOS native and target support for 386
6066 This release has been hosted on LynxOS 2.2, and also can be configured
6067 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6070 * Improvements in C++ mangling/demangling.
6072 This release has much better g++ debugging, specifically in name
6073 mangling/demangling, virtual function calls, print virtual table,
6074 call methods, ...etc.
6076 *** Changes in GDB-4.10:
6078 * User visible changes:
6080 Remote debugging using the GDB-specific (`target remote') protocol now
6081 supports the `load' command. This is only useful if you have some
6082 other way of getting the stub to the target system, and you can put it
6083 somewhere in memory where it won't get clobbered by the download.
6085 Filename completion now works.
6087 When run under emacs mode, the "info line" command now causes the
6088 arrow to point to the line specified. Also, "info line" prints
6089 addresses in symbolic form (as well as hex).
6091 All vxworks based targets now support a user settable option, called
6092 vxworks-timeout. This option represents the number of seconds gdb
6093 should wait for responses to rpc's. You might want to use this if
6094 your vxworks target is, perhaps, a slow software simulator or happens
6095 to be on the far side of a thin network line.
6099 This release contains support for using a DEC alpha as a GDB host for
6100 cross debugging. Native alpha debugging is not supported yet.
6103 *** Changes in GDB-4.9:
6107 This is the first GDB release which is accompanied by a matching testsuite.
6108 The testsuite requires installation of dejagnu, which should be available
6109 via ftp from most sites that carry GNU software.
6113 'Cfront' style demangling has had its name changed to 'ARM' style, to
6114 emphasize that it was written from the specifications in the C++ Annotated
6115 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6116 disclaimers, it still generated too much confusion with users attempting to
6117 use gdb with AT&T cfront.
6121 GDB now uses a standard remote interface to a simulator library.
6122 So far, the library contains simulators for the Zilog Z8001/2, the
6123 Hitachi H8/300, H8/500 and Super-H.
6125 * New targets supported
6127 H8/300 simulator h8300-hitachi-hms or h8300hms
6128 H8/500 simulator h8500-hitachi-hms or h8500hms
6129 SH simulator sh-hitachi-hms or sh
6130 Z8000 simulator z8k-zilog-none or z8ksim
6131 IDT MIPS board over serial line mips-idt-ecoff
6133 Cross-debugging to GO32 targets is supported. It requires a custom
6134 version of the i386-stub.c module which is integrated with the
6135 GO32 memory extender.
6137 * New remote protocols
6139 MIPS remote debugging protocol.
6141 * New source languages supported
6143 This version includes preliminary support for Chill, a Pascal like language
6144 used by telecommunications companies. Chill support is also being integrated
6145 into the GNU compiler, but we don't know when it will be publically available.
6148 *** Changes in GDB-4.8:
6150 * HP Precision Architecture supported
6152 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6153 version of this support was available as a set of patches from the
6154 University of Utah. GDB does not support debugging of programs
6155 compiled with the HP compiler, because HP will not document their file
6156 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6157 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6159 Many problems in the preliminary version have been fixed.
6161 * Faster and better demangling
6163 We have improved template demangling and fixed numerous bugs in the GNU style
6164 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6165 character types (wchar_t) are now supported. Demangling of each symbol is now
6166 only done once, and is cached when the symbol table for a file is read in.
6167 This results in a small increase in memory usage for C programs, a moderate
6168 increase in memory usage for C++ programs, and a fantastic speedup in
6171 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6172 from the specifications in the Annotated Reference Manual, which AT&T's
6173 compiler does not actually implement.
6175 * G++ multiple inheritance compiler problem
6177 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6178 inheritance lattices was reworked to properly discover ambiguities. We
6179 recently found an example which causes this new algorithm to fail in a
6180 very subtle way, producing bad debug information for those classes.
6181 The file 'gcc.patch' (in this directory) can be applied to gcc to
6182 circumvent the problem. A future GCC release will contain a complete
6185 The previous G++ debug info problem (mentioned below for the gdb-4.7
6186 release) is fixed in gcc version 2.3.2.
6188 * Improved configure script
6190 The `configure' script will now attempt to guess your system type if
6191 you don't supply a host system type. The old scheme of supplying a
6192 host system triplet is preferable over using this. All the magic is
6193 done in the new `config.guess' script. Examine it for details.
6195 We have also brought our configure script much more in line with the FSF's
6196 version. It now supports the --with-xxx options. In particular,
6197 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6198 The resulting GDB will not be able to read arbitrary object file formats --
6199 only the format ``expected'' to be used on the configured target system.
6200 We hope to make this the default in a future release.
6202 * Documentation improvements
6204 There's new internal documentation on how to modify GDB, and how to
6205 produce clean changes to the code. We implore people to read it
6206 before submitting changes.
6208 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6209 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6210 `info' files are also provided. To build `info' files from scratch,
6211 you will need the latest `makeinfo' release, which will be available in
6212 a future texinfo-X.Y release.
6214 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6215 We're not sure exactly which versions have this problem, but it has
6216 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6217 or better. If that isn't possible, there is a patch in
6218 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6219 around this problem.
6223 GDB now supports array constants that can be used in expressions typed in by
6224 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6225 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6228 The new directory `gdb/sparclite' contains a program that demonstrates
6229 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6231 * New native hosts supported
6233 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6234 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6236 * New targets supported
6238 AMD 29k family via UDI a29k-amd-udi or udi29k
6240 * New file formats supported
6242 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6243 HPUX core files, and SCO 3.2v2 core files.
6247 Attaching to processes now works again; thanks for the many bug reports.
6249 We have also stomped on a bunch of core dumps caused by
6250 printf_filtered("%s") problems.
6252 We eliminated a copyright problem on the rpc and ptrace header files
6253 for VxWorks, which was discovered at the last minute during the 4.7
6254 release. You should now be able to build a VxWorks GDB.
6256 You can now interrupt gdb while an attached process is running. This
6257 will cause the attached process to stop, and give control back to GDB.
6259 We fixed problems caused by using too many file descriptors
6260 for reading symbols from object files and libraries. This was
6261 especially a problem for programs that used many (~100) shared
6264 The `step' command now only enters a subroutine if there is line number
6265 information for the subroutine. Otherwise it acts like the `next'
6266 command. Previously, `step' would enter subroutines if there was
6267 any debugging information about the routine. This avoids problems
6268 when using `cc -g1' on MIPS machines.
6270 * Internal improvements
6272 GDB's internal interfaces have been improved to make it easier to support
6273 debugging of multiple languages in the future.
6275 GDB now uses a common structure for symbol information internally.
6276 Minimal symbols (derived from linkage symbols in object files), partial
6277 symbols (from a quick scan of debug information), and full symbols
6278 contain a common subset of information, making it easier to write
6279 shared code that handles any of them.
6281 * New command line options
6283 We now accept --silent as an alias for --quiet.
6287 The memory-mapped-malloc library is now licensed under the GNU Library
6288 General Public License.
6290 *** Changes in GDB-4.7:
6292 * Host/native/target split
6294 GDB has had some major internal surgery to untangle the support for
6295 hosts and remote targets. Now, when you configure GDB for a remote
6296 target, it will no longer load in all of the support for debugging
6297 local programs on the host. When fully completed and tested, this will
6298 ensure that arbitrary host/target combinations are possible.
6300 The primary conceptual shift is to separate the non-portable code in
6301 GDB into three categories. Host specific code is required any time GDB
6302 is compiled on that host, regardless of the target. Target specific
6303 code relates to the peculiarities of the target, but can be compiled on
6304 any host. Native specific code is everything else: it can only be
6305 built when the host and target are the same system. Child process
6306 handling and core file support are two common `native' examples.
6308 GDB's use of /proc for controlling Unix child processes is now cleaner.
6309 It has been split out into a single module under the `target_ops' vector,
6310 plus two native-dependent functions for each system that uses /proc.
6312 * New hosts supported
6314 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6315 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6316 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6318 * New targets supported
6320 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6321 68030 and CPU32 m68030-*-*, m68332-*-*
6323 * New native hosts supported
6325 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6326 (386bsd is not well tested yet)
6327 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6329 * New file formats supported
6331 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6332 supports reading of `a.out.adobe' object files, which are an a.out
6333 format extended with minimal information about multiple sections.
6337 `show copying' is the same as the old `info copying'.
6338 `show warranty' is the same as `info warrantee'.
6339 These were renamed for consistency. The old commands continue to work.
6341 `info handle' is a new alias for `info signals'.
6343 You can now define pre-command hooks, which attach arbitrary command
6344 scripts to any command. The commands in the hook will be executed
6345 prior to the user's command. You can also create a hook which will be
6346 executed whenever the program stops. See gdb.texinfo.
6350 We now deal with Cfront style name mangling, and can even extract type
6351 info from mangled symbols. GDB can automatically figure out which
6352 symbol mangling style your C++ compiler uses.
6354 Calling of methods and virtual functions has been improved as well.
6358 The crash that occured when debugging Sun Ansi-C compiled binaries is
6359 fixed. This was due to mishandling of the extra N_SO stabs output
6362 We also finally got Ultrix 4.2 running in house, and fixed core file
6363 support, with help from a dozen people on the net.
6365 John M. Farrell discovered that the reason that single-stepping was so
6366 slow on all of the Mips based platforms (primarily SGI and DEC) was
6367 that we were trying to demangle and lookup a symbol used for internal
6368 purposes on every instruction that was being stepped through. Changing
6369 the name of that symbol so that it couldn't be mistaken for a C++
6370 mangled symbol sped things up a great deal.
6372 Rich Pixley sped up symbol lookups in general by getting much smarter
6373 about when C++ symbol mangling is necessary. This should make symbol
6374 completion (TAB on the command line) much faster. It's not as fast as
6375 we'd like, but it's significantly faster than gdb-4.6.
6379 A new user controllable variable 'call_scratch_address' can
6380 specify the location of a scratch area to be used when GDB
6381 calls a function in the target. This is necessary because the
6382 usual method of putting the scratch area on the stack does not work
6383 in systems that have separate instruction and data spaces.
6385 We integrated changes to support the 29k UDI (Universal Debugger
6386 Interface), but discovered at the last minute that we didn't have all
6387 of the appropriate copyright paperwork. We are working with AMD to
6388 resolve this, and hope to have it available soon.
6392 We have sped up the remote serial line protocol, especially for targets
6393 with lots of registers. It now supports a new `expedited status' ('T')
6394 message which can be used in place of the existing 'S' status message.
6395 This allows the remote stub to send only the registers that GDB
6396 needs to make a quick decision about single-stepping or conditional
6397 breakpoints, eliminating the need to fetch the entire register set for
6398 each instruction being stepped through.
6400 The GDB remote serial protocol now implements a write-through cache for
6401 registers, only re-reading the registers if the target has run.
6403 There is also a new remote serial stub for SPARC processors. You can
6404 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6405 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6406 processor with a serial port.
6410 Configure.in files have become much easier to read and modify. A new
6411 `table driven' format makes it more obvious what configurations are
6412 supported, and what files each one uses.
6416 There is a new opcodes library which will eventually contain all of the
6417 disassembly routines and opcode tables. At present, it only contains
6418 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6419 disassembler (binutils/objdump) to share these routines.
6421 The libiberty library is now copylefted under the GNU Library General
6422 Public License. This allows more liberal use, and was done so libg++
6423 can use it. This makes no difference to GDB, since the Library License
6424 grants all the rights from the General Public License.
6428 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6429 reference to the stabs symbol info used by the debugger. It is (as far
6430 as we know) the only published document on this fascinating topic. We
6431 encourage you to read it, compare it to the stabs information on your
6432 system, and send improvements on the document in general (to
6433 bug-gdb@prep.ai.mit.edu).
6435 And, of course, many bugs have been fixed.
6438 *** Changes in GDB-4.6:
6440 * Better support for C++ function names
6442 GDB now accepts as input the "demangled form" of C++ overloaded function
6443 names and member function names, and can do command completion on such names
6444 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6445 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6446 Make use of command completion, it is your friend.
6448 GDB also now accepts a variety of C++ mangled symbol formats. They are
6449 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6450 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6451 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6452 for the list of formats.
6454 * G++ symbol mangling problem
6456 Recent versions of gcc have a bug in how they emit debugging information for
6457 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6458 directory) can be applied to gcc to fix the problem. Alternatively, if you
6459 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6460 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6461 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6464 * New 'maintenance' command
6466 All of the commands related to hacking GDB internals have been moved out of
6467 the main command set, and now live behind the 'maintenance' command. This
6468 can also be abbreviated as 'mt'. The following changes were made:
6470 dump-me -> maintenance dump-me
6471 info all-breakpoints -> maintenance info breakpoints
6472 printmsyms -> maintenance print msyms
6473 printobjfiles -> maintenance print objfiles
6474 printpsyms -> maintenance print psymbols
6475 printsyms -> maintenance print symbols
6477 The following commands are new:
6479 maintenance demangle Call internal GDB demangler routine to
6480 demangle a C++ link name and prints the result.
6481 maintenance print type Print a type chain for a given symbol
6483 * Change to .gdbinit file processing
6485 We now read the $HOME/.gdbinit file before processing the argv arguments
6486 (e.g. reading symbol files or core files). This allows global parameters to
6487 be set, which will apply during the symbol reading. The ./.gdbinit is still
6488 read after argv processing.
6490 * New hosts supported
6492 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6494 GNU/Linux support i386-unknown-linux or linux
6496 We are also including code to support the HP/PA running BSD and HPUX. This
6497 is almost guaranteed not to work, as we didn't have time to test or build it
6498 for this release. We are including it so that the more adventurous (or
6499 masochistic) of you can play with it. We also had major problems with the
6500 fact that the compiler that we got from HP doesn't support the -g option.
6503 * New targets supported
6505 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6507 * More smarts about finding #include files
6509 GDB now remembers the compilation directory for all include files, and for
6510 all files from which C is generated (like yacc and lex sources). This
6511 greatly improves GDB's ability to find yacc/lex sources, and include files,
6512 especially if you are debugging your program from a directory different from
6513 the one that contains your sources.
6515 We also fixed a bug which caused difficulty with listing and setting
6516 breakpoints in include files which contain C code. (In the past, you had to
6517 try twice in order to list an include file that you hadn't looked at before.)
6519 * Interesting infernals change
6521 GDB now deals with arbitrary numbers of sections, where the symbols for each
6522 section must be relocated relative to that section's landing place in the
6523 target's address space. This work was needed to support ELF with embedded
6524 stabs used by Solaris-2.0.
6526 * Bug fixes (of course!)
6528 There have been loads of fixes for the following things:
6529 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6530 i960, stabs, DOS(GO32), procfs, etc...
6532 See the ChangeLog for details.
6534 *** Changes in GDB-4.5:
6536 * New machines supported (host and target)
6538 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6540 SGI Irix-4.x mips-sgi-irix4 or iris4
6542 * New malloc package
6544 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6545 Mmalloc is capable of handling mutiple heaps of memory. It is also
6546 capable of saving a heap to a file, and then mapping it back in later.
6547 This can be used to greatly speedup the startup of GDB by using a
6548 pre-parsed symbol table which lives in a mmalloc managed heap. For
6549 more details, please read mmalloc/mmalloc.texi.
6553 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6554 'help info proc' for details.
6556 * MIPS ecoff symbol table format
6558 The code that reads MIPS symbol table format is now supported on all hosts.
6559 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6562 * File name changes for MS-DOS
6564 Many files in the config directories have been renamed to make it easier to
6565 support GDB on MS-DOSe systems (which have very restrictive file name
6566 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6567 environment) is close to working but has some remaining problems. Note
6568 that debugging of DOS programs is not supported, due to limitations
6569 in the ``operating system'', but it can be used to host cross-debugging.
6571 * Cross byte order fixes
6573 Many fixes have been made to support cross debugging of Sparc and MIPS
6574 targets from hosts whose byte order differs.
6576 * New -mapped and -readnow options
6578 If memory-mapped files are available on your system through the 'mmap'
6579 system call, you can use the -mapped option on the `file' or
6580 `symbol-file' commands to cause GDB to write the symbols from your
6581 program into a reusable file. If the program you are debugging is
6582 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6583 Future GDB debugging sessions will notice the presence of this file,
6584 and will quickly map in symbol information from it, rather than reading
6585 the symbol table from the executable program. Using the '-mapped'
6586 option in a GDB `file' or `symbol-file' command has the same effect as
6587 starting GDB with the '-mapped' command-line option.
6589 You can cause GDB to read the entire symbol table immediately by using
6590 the '-readnow' option with any of the commands that load symbol table
6591 information (or on the GDB command line). This makes the command
6592 slower, but makes future operations faster.
6594 The -mapped and -readnow options are typically combined in order to
6595 build a `fred.syms' file that contains complete symbol information.
6596 A simple GDB invocation to do nothing but build a `.syms' file for future
6599 gdb -batch -nx -mapped -readnow programname
6601 The `.syms' file is specific to the host machine on which GDB is run.
6602 It holds an exact image of GDB's internal symbol table. It cannot be
6603 shared across multiple host platforms.
6605 * longjmp() handling
6607 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6608 siglongjmp() without losing control. This feature has not yet been ported to
6609 all systems. It currently works on many 386 platforms, all MIPS-based
6610 platforms (SGI, DECstation, etc), and Sun3/4.
6614 Preliminary work has been put in to support the new Solaris OS from Sun. At
6615 this time, it can control and debug processes, but it is not capable of
6620 As always, many many bug fixes. The major areas were with g++, and mipsread.
6621 People using the MIPS-based platforms should experience fewer mysterious
6622 crashes and trashed symbol tables.
6624 *** Changes in GDB-4.4:
6626 * New machines supported (host and target)
6628 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6630 BSD Reno on Vax vax-dec-bsd
6631 Ultrix on Vax vax-dec-ultrix
6633 * New machines supported (target)
6635 AMD 29000 embedded, using EBMON a29k-none-none
6639 GDB continues to improve its handling of C++. `References' work better.
6640 The demangler has also been improved, and now deals with symbols mangled as
6641 per the Annotated C++ Reference Guide.
6643 GDB also now handles `stabs' symbol information embedded in MIPS
6644 `ecoff' symbol tables. Since the ecoff format was not easily
6645 extensible to handle new languages such as C++, this appeared to be a
6646 good way to put C++ debugging info into MIPS binaries. This option
6647 will be supported in the GNU C compiler, version 2, when it is
6650 * New features for SVR4
6652 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6653 shared libraries. Debugging dynamically linked programs should present
6654 only minor differences from debugging statically linked programs.
6656 The `info proc' command will print out information about any process
6657 on an SVR4 system (including the one you are debugging). At the moment,
6658 it prints the address mappings of the process.
6660 If you bring up GDB on another SVR4 system, please send mail to
6661 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6663 * Better dynamic linking support in SunOS
6665 Reading symbols from shared libraries which contain debugging symbols
6666 now works properly. However, there remain issues such as automatic
6667 skipping of `transfer vector' code during function calls, which
6668 make it harder to debug code in a shared library, than to debug the
6669 same code linked statically.
6673 GDB is now using the latest `getopt' routines from the FSF. This
6674 version accepts the -- prefix for options with long names. GDB will
6675 continue to accept the old forms (-option and +option) as well.
6676 Various single letter abbreviations for options have been explicity
6677 added to the option table so that they won't get overshadowed in the
6678 future by other options that begin with the same letter.
6682 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6683 Many assorted bugs have been handled. Many more remain to be handled.
6684 See the various ChangeLog files (primarily in gdb and bfd) for details.
6687 *** Changes in GDB-4.3:
6689 * New machines supported (host and target)
6691 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6692 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6693 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6695 * Almost SCO Unix support
6697 We had hoped to support:
6698 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6699 (except for core file support), but we discovered very late in the release
6700 that it has problems with process groups that render gdb unusable. Sorry
6701 about that. I encourage people to fix it and post the fixes.
6703 * Preliminary ELF and DWARF support
6705 GDB can read ELF object files on System V Release 4, and can handle
6706 debugging records for C, in DWARF format, in ELF files. This support
6707 is preliminary. If you bring up GDB on another SVR4 system, please
6708 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6713 GDB now uses the latest `readline' library. One user-visible change
6714 is that two tabs will list possible command completions, which previously
6715 required typing M-? (meta-question mark, or ESC ?).
6719 The `stepi' bug that many of you noticed has been squashed.
6720 Many bugs in C++ have been handled. Many more remain to be handled.
6721 See the various ChangeLog files (primarily in gdb and bfd) for details.
6723 * State of the MIPS world (in case you wondered):
6725 GDB can understand the symbol tables emitted by the compilers
6726 supplied by most vendors of MIPS-based machines, including DEC. These
6727 symbol tables are in a format that essentially nobody else uses.
6729 Some versions of gcc come with an assembler post-processor called
6730 mips-tfile. This program is required if you want to do source-level
6731 debugging of gcc-compiled programs. I believe FSF does not ship
6732 mips-tfile with gcc version 1, but it will eventually come with gcc
6735 Debugging of g++ output remains a problem. g++ version 1.xx does not
6736 really support it at all. (If you're lucky, you should be able to get
6737 line numbers and stack traces to work, but no parameters or local
6738 variables.) With some work it should be possible to improve the
6741 When gcc version 2 is released, you will have somewhat better luck.
6742 However, even then you will get confusing results for inheritance and
6745 We will eventually provide full debugging of g++ output on
6746 DECstations. This will probably involve some kind of stabs-in-ecoff
6747 encapulation, but the details have not been worked out yet.
6750 *** Changes in GDB-4.2:
6752 * Improved configuration
6754 Only one copy of `configure' exists now, and it is not self-modifying.
6755 Porting BFD is simpler.
6759 The `step' and `next' commands now only stop at the first instruction
6760 of a source line. This prevents the multiple stops that used to occur
6761 in switch statements, for-loops, etc. `Step' continues to stop if a
6762 function that has debugging information is called within the line.
6766 Lots of small bugs fixed. More remain.
6768 * New host supported (not target)
6770 Intel 386 PC clone running Mach i386-none-mach
6773 *** Changes in GDB-4.1:
6775 * Multiple source language support
6777 GDB now has internal scaffolding to handle several source languages.
6778 It determines the type of each source file from its filename extension,
6779 and will switch expression parsing and number formatting to match the
6780 language of the function in the currently selected stack frame.
6781 You can also specifically set the language to be used, with
6782 `set language c' or `set language modula-2'.
6786 GDB now has preliminary support for the GNU Modula-2 compiler,
6787 currently under development at the State University of New York at
6788 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6789 continue through the fall of 1991 and into 1992.
6791 Other Modula-2 compilers are currently not supported, and attempting to
6792 debug programs compiled with them will likely result in an error as the
6793 symbol table is read. Feel free to work on it, though!
6795 There are hooks in GDB for strict type checking and range checking,
6796 in the `Modula-2 philosophy', but they do not currently work.
6800 GDB can now write to executable and core files (e.g. patch
6801 a variable's value). You must turn this switch on, specify
6802 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6803 by assigning a new value to a variable. Modifications take
6806 * Automatic SunOS shared library reading
6808 When you run your program, GDB automatically determines where its
6809 shared libraries (if any) have been loaded, and reads their symbols.
6810 The `share' command is no longer needed. This also works when
6811 examining core files.
6815 You can specify the number of lines that the `list' command shows.
6818 * New machines supported (host and target)
6820 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6821 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6822 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6824 * New hosts supported (not targets)
6826 IBM RT/PC: romp-ibm-aix or rtpc
6828 * New targets supported (not hosts)
6830 AMD 29000 embedded with COFF a29k-none-coff
6831 AMD 29000 embedded with a.out a29k-none-aout
6832 Ultracomputer remote kernel debug a29k-nyu-kern
6834 * New remote interfaces
6840 *** Changes in GDB-4.0:
6844 Wide output is wrapped at good places to make the output more readable.
6846 Gdb now supports cross-debugging from a host machine of one type to a
6847 target machine of another type. Communication with the target system
6848 is over serial lines. The ``target'' command handles connecting to the
6849 remote system; the ``load'' command will download a program into the
6850 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6851 also supports debugging of realtime processes running under VxWorks,
6852 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6853 stub on the target system.
6855 New CPUs supported include the AMD 29000 and Intel 960.
6857 GDB now reads object files and symbol tables via a ``binary file''
6858 library, which allows a single copy of GDB to debug programs of multiple
6859 object file types such as a.out and coff.
6861 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6862 refcard.dvi and refcard.ps are available to format it).
6865 * Control-Variable user interface simplified
6867 All variables that control the operation of the debugger can be set
6868 by the ``set'' command, and displayed by the ``show'' command.
6870 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6871 ``Show prompt'' produces the response:
6872 Gdb's prompt is new-gdb=>.
6874 What follows are the NEW set commands. The command ``help set'' will
6875 print a complete list of old and new set commands. ``help set FOO''
6876 will give a longer description of the variable FOO. ``show'' will show
6877 all of the variable descriptions and their current settings.
6879 confirm on/off: Enables warning questions for operations that are
6880 hard to recover from, e.g. rerunning the program while
6881 it is already running. Default is ON.
6883 editing on/off: Enables EMACS style command line editing
6884 of input. Previous lines can be recalled with
6885 control-P, the current line can be edited with control-B,
6886 you can search for commands with control-R, etc.
6889 history filename NAME: NAME is where the gdb command history
6890 will be stored. The default is .gdb_history,
6891 or the value of the environment variable
6894 history size N: The size, in commands, of the command history. The
6895 default is 256, or the value of the environment variable
6898 history save on/off: If this value is set to ON, the history file will
6899 be saved after exiting gdb. If set to OFF, the
6900 file will not be saved. The default is OFF.
6902 history expansion on/off: If this value is set to ON, then csh-like
6903 history expansion will be performed on
6904 command line input. The default is OFF.
6906 radix N: Sets the default radix for input and output. It can be set
6907 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6908 in the current radix, so "set radix 10" is always a no-op.
6910 height N: This integer value is the number of lines on a page. Default
6911 is 24, the current `stty rows'' setting, or the ``li#''
6912 setting from the termcap entry matching the environment
6915 width N: This integer value is the number of characters on a line.
6916 Default is 80, the current `stty cols'' setting, or the ``co#''
6917 setting from the termcap entry matching the environment
6920 Note: ``set screensize'' is obsolete. Use ``set height'' and
6921 ``set width'' instead.
6923 print address on/off: Print memory addresses in various command displays,
6924 such as stack traces and structure values. Gdb looks
6925 more ``symbolic'' if you turn this off; it looks more
6926 ``machine level'' with it on. Default is ON.
6928 print array on/off: Prettyprint arrays. New convenient format! Default
6931 print demangle on/off: Print C++ symbols in "source" form if on,
6934 print asm-demangle on/off: Same, for assembler level printouts
6937 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6940 * Support for Epoch Environment.
6942 The epoch environment is a version of Emacs v18 with windowing. One
6943 new command, ``inspect'', is identical to ``print'', except that if you
6944 are running in the epoch environment, the value is printed in its own
6948 * Support for Shared Libraries
6950 GDB can now debug programs and core files that use SunOS shared libraries.
6951 Symbols from a shared library cannot be referenced
6952 before the shared library has been linked with the program (this
6953 happens after you type ``run'' and before the function main() is entered).
6954 At any time after this linking (including when examining core files
6955 from dynamically linked programs), gdb reads the symbols from each
6956 shared library when you type the ``sharedlibrary'' command.
6957 It can be abbreviated ``share''.
6959 sharedlibrary REGEXP: Load shared object library symbols for files
6960 matching a unix regular expression. No argument
6961 indicates to load symbols for all shared libraries.
6963 info sharedlibrary: Status of loaded shared libraries.
6968 A watchpoint stops execution of a program whenever the value of an
6969 expression changes. Checking for this slows down execution
6970 tremendously whenever you are in the scope of the expression, but is
6971 quite useful for catching tough ``bit-spreader'' or pointer misuse
6972 problems. Some machines such as the 386 have hardware for doing this
6973 more quickly, and future versions of gdb will use this hardware.
6975 watch EXP: Set a watchpoint (breakpoint) for an expression.
6977 info watchpoints: Information about your watchpoints.
6979 delete N: Deletes watchpoint number N (same as breakpoints).
6980 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6981 enable N: Re-enables watchpoint number N (same as breakpoints).
6984 * C++ multiple inheritance
6986 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6989 * C++ exception handling
6991 Gdb now supports limited C++ exception handling. Besides the existing
6992 ability to breakpoint on an exception handler, gdb can breakpoint on
6993 the raising of an exception (before the stack is peeled back to the
6996 catch FOO: If there is a FOO exception handler in the dynamic scope,
6997 set a breakpoint to catch exceptions which may be raised there.
6998 Multiple exceptions (``catch foo bar baz'') may be caught.
7000 info catch: Lists all exceptions which may be caught in the
7001 current stack frame.
7004 * Minor command changes
7006 The command ``call func (arg, arg, ...)'' now acts like the print
7007 command, except it does not print or save a value if the function's result
7008 is void. This is similar to dbx usage.
7010 The ``up'' and ``down'' commands now always print the frame they end up
7011 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7012 frames without printing.
7014 * New directory command
7016 'dir' now adds directories to the FRONT of the source search path.
7017 The path starts off empty. Source files that contain debug information
7018 about the directory in which they were compiled can be found even
7019 with an empty path; Sun CC and GCC include this information. If GDB can't
7020 find your source file in the current directory, type "dir .".
7022 * Configuring GDB for compilation
7024 For normal use, type ``./configure host''. See README or gdb.texinfo
7027 GDB now handles cross debugging. If you are remotely debugging between
7028 two different machines, type ``./configure host -target=targ''.
7029 Host is the machine where GDB will run; targ is the machine
7030 where the program that you are debugging will run.