1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The 'symbol-file' command now accepts an '-o' option to add a relative
7 offset to all sections.
9 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
10 a relative offset to all sections, but it allows to override the load
11 address of individual sections using '-s'.
13 * The 'add-symbol-file' command no longer requires the second argument
14 (address of the text section).
16 * The endianness used with the 'set endian auto' mode in the absence of
17 an executable selected for debugging is now the last endianness chosen
18 either by one of the 'set endian big' and 'set endian little' commands
19 or by inferring from the last executable used, rather than the startup
22 * The pager now allows a "c" response, meaning to disable the pager
23 for the rest of the current command.
25 * The commands 'info variables/functions/types' now show the source line
26 numbers of symbol definitions when available.
28 * 'info proc' now works on running processes on FreeBSD systems and core
29 files created on FreeBSD systems.
31 * C expressions can now use _Alignof, and C++ expressions can now use
38 Control display of debugging info regarding the FreeBSD native target.
40 set|show varsize-limit
41 This new setting allows the user to control the maximum size of Ada
42 objects being printed when those objects have a variable type,
43 instead of that maximum size being hardcoded to 65536 bytes.
45 set|show record btrace cpu
46 Controls the processor to be used for enabling errata workarounds for
49 maint check libthread-db
50 Run integrity checks on the current inferior's thread debugging
53 maint set check-libthread-db (on|off)
54 maint show check-libthread-db
55 Control whether to run integrity checks on inferior specific thread
56 debugging libraries as they are loaded. The default is not to
61 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
63 ** The commands attached to a breakpoint can be set by assigning to
64 the breakpoint's "commands" field.
66 ** gdb.execute can now execute multi-line gdb commands.
68 ** The new functions gdb.convenience_variable and
69 gdb.set_convenience_variable can be used to get and set the value
70 of convenience variables.
72 ** A gdb.Parameter will no longer print the "set" help text on an
73 ordinary "set"; instead by default a "set" will be silent unless
74 the get_set_string method returns a non-empty string.
78 RiscV ELF riscv*-*-elf
80 * Removed targets and native configurations
82 m88k running OpenBSD m88*-*-openbsd*
83 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
84 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
85 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
87 * Aarch64/Linux hardware watchpoints improvements
89 Hardware watchpoints on unaligned addresses are now properly
90 supported when running Linux kernel 4.10 or higher: read and access
91 watchpoints are no longer spuriously missed, and all watchpoints
92 lengths between 1 and 8 bytes are supported. On older kernels,
93 watchpoints set on unaligned addresses are no longer missed, with
94 the tradeoff that there is a possibility of false hits being
97 *** Changes in GDB 8.1
99 * GDB now supports dynamically creating arbitrary register groups specified
100 in XML target descriptions. This allows for finer grain grouping of
101 registers on systems with a large amount of registers.
103 * The 'ptype' command now accepts a '/o' flag, which prints the
104 offsets and sizes of fields in a struct, like the pahole(1) tool.
106 * New "--readnever" command line option instructs GDB to not read each
107 symbol file's symbolic debug information. This makes startup faster
108 but at the expense of not being able to perform symbolic debugging.
109 This option is intended for use cases where symbolic debugging will
110 not be used, e.g., when you only need to dump the debuggee's core.
112 * GDB now uses the GNU MPFR library, if available, to emulate target
113 floating-point arithmetic during expression evaluation when the target
114 uses different floating-point formats than the host. At least version
115 3.1 of GNU MPFR is required.
117 * GDB now supports access to the guarded-storage-control registers and the
118 software-based guarded-storage broadcast control registers on IBM z14.
120 * On Unix systems, GDB now supports transmitting environment variables
121 that are to be set or unset to GDBserver. These variables will
122 affect the environment to be passed to the remote inferior.
124 To inform GDB of environment variables that are to be transmitted to
125 GDBserver, use the "set environment" command. Only user set
126 environment variables are sent to GDBserver.
128 To inform GDB of environment variables that are to be unset before
129 the remote inferior is started by the GDBserver, use the "unset
130 environment" command.
132 * Completion improvements
134 ** GDB can now complete function parameters in linespecs and
135 explicit locations without quoting. When setting breakpoints,
136 quoting around functions names to help with TAB-completion is
137 generally no longer necessary. For example, this now completes
140 (gdb) b function(in[TAB]
141 (gdb) b function(int)
143 Related, GDB is no longer confused with completing functions in
144 C++ anonymous namespaces:
147 (gdb) b (anonymous namespace)::[TAB][TAB]
148 (anonymous namespace)::a_function()
149 (anonymous namespace)::b_function()
151 ** GDB now has much improved linespec and explicit locations TAB
152 completion support, that better understands what you're
153 completing and offers better suggestions. For example, GDB no
154 longer offers data symbols as possible completions when you're
155 setting a breakpoint.
157 ** GDB now TAB-completes label symbol names.
159 ** The "complete" command now mimics TAB completion accurately.
161 * New command line options (gcore)
164 Dump all memory mappings.
166 * Breakpoints on C++ functions are now set on all scopes by default
168 By default, breakpoints on functions/methods are now interpreted as
169 specifying all functions with the given name ignoring missing
170 leading scopes (namespaces and classes).
172 For example, assuming a C++ program with symbols named:
177 both commands "break func()" and "break B::func()" set a breakpoint
180 You can use the new flag "-qualified" to override this. This makes
181 GDB interpret the specified function name as a complete
182 fully-qualified name instead. For example, using the same C++
183 program, the "break -q B::func" command sets a breakpoint on
184 "B::func", only. A parameter has been added to the Python
185 gdb.Breakpoint constructor to achieve the same result when creating
186 a breakpoint from Python.
188 * Breakpoints on functions marked with C++ ABI tags
190 GDB can now set breakpoints on functions marked with C++ ABI tags
191 (e.g., [abi:cxx11]). See here for a description of ABI tags:
192 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
194 Functions with a C++11 abi tag are demangled/displayed like this:
196 function[abi:cxx11](int)
199 You can now set a breakpoint on such functions simply as if they had
202 (gdb) b function(int)
204 Or if you need to disambiguate between tags, like:
206 (gdb) b function[abi:other_tag](int)
208 Tab completion was adjusted accordingly as well.
212 ** New events gdb.new_inferior, gdb.inferior_deleted, and
213 gdb.new_thread are emitted. See the manual for further
214 description of these.
216 ** A new function, "gdb.rbreak" has been added to the Python API.
217 This function allows the setting of a large number of breakpoints
218 via a regex pattern in Python. See the manual for further details.
220 ** Python breakpoints can now accept explicit locations. See the
221 manual for a further description of this feature.
224 * New features in the GDB remote stub, GDBserver
226 ** GDBserver is now able to start inferior processes with a
227 specified initial working directory.
229 The user can set the desired working directory to be used from
230 GDB using the new "set cwd" command.
232 ** New "--selftest" command line option runs some GDBserver self
233 tests. These self tests are disabled in releases.
235 ** On Unix systems, GDBserver now does globbing expansion and variable
236 substitution in inferior command line arguments.
238 This is done by starting inferiors using a shell, like GDB does.
239 See "set startup-with-shell" in the user manual for how to disable
240 this from GDB when using "target extended-remote". When using
241 "target remote", you can disable the startup with shell by using the
242 new "--no-startup-with-shell" GDBserver command line option.
244 ** On Unix systems, GDBserver now supports receiving environment
245 variables that are to be set or unset from GDB. These variables
246 will affect the environment to be passed to the inferior.
248 * When catching an Ada exception raised with a message, GDB now prints
249 the message in the catchpoint hit notification. In GDB/MI mode, that
250 information is provided as an extra field named "exception-message"
251 in the *stopped notification.
253 * Trait objects can now be inspected When debugging Rust code. This
254 requires compiler support which will appear in Rust 1.24.
258 QEnvironmentHexEncoded
259 Inform GDBserver of an environment variable that is to be passed to
260 the inferior when starting it.
263 Inform GDBserver of an environment variable that is to be unset
264 before starting the remote inferior.
267 Inform GDBserver that the environment should be reset (i.e.,
268 user-set environment variables should be unset).
271 Indicates whether the inferior must be started with a shell or not.
274 Tell GDBserver that the inferior to be started should use a specific
277 * The "maintenance print c-tdesc" command now takes an optional
278 argument which is the file name of XML target description.
280 * The "maintenance selftest" command now takes an optional argument to
281 filter the tests to be run.
283 * The "enable", and "disable" commands now accept a range of
284 breakpoint locations, e.g. "enable 1.3-5".
289 Set and show the current working directory for the inferior.
292 Set and show compilation command used for compiling and injecting code
293 with the 'compile' commands.
295 set debug separate-debug-file
296 show debug separate-debug-file
297 Control the display of debug output about separate debug file search.
299 set dump-excluded-mappings
300 show dump-excluded-mappings
301 Control whether mappings marked with the VM_DONTDUMP flag should be
302 dumped when generating a core file.
305 List the registered selftests.
308 Start the debugged program stopping at the first instruction.
311 Control display of debugging messages related to OpenRISC targets.
313 set|show print type nested-type-limit
314 Set and show the limit of nesting level for nested types that the
315 type printer will show.
317 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
320 * Safer/improved support for debugging with no debug info
322 GDB no longer assumes functions with no debug information return
325 This means that GDB now refuses to call such functions unless you
326 tell it the function's type, by either casting the call to the
327 declared return type, or by casting the function to a function
328 pointer of the right type, and calling that:
330 (gdb) p getenv ("PATH")
331 'getenv' has unknown return type; cast the call to its declared return type
332 (gdb) p (char *) getenv ("PATH")
333 $1 = 0x7fffffffe "/usr/local/bin:/"...
334 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
335 $2 = 0x7fffffffe "/usr/local/bin:/"...
337 Similarly, GDB no longer assumes that global variables with no debug
338 info have type 'int', and refuses to print the variable's value
339 unless you tell it the variable's type:
342 'var' has unknown type; cast it to its declared type
346 * New native configurations
348 FreeBSD/aarch64 aarch64*-*-freebsd*
349 FreeBSD/arm arm*-*-freebsd*
353 FreeBSD/aarch64 aarch64*-*-freebsd*
354 FreeBSD/arm arm*-*-freebsd*
355 OpenRISC ELF or1k*-*-elf
357 * Removed targets and native configurations
359 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
361 *** Changes in GDB 8.0
363 * GDB now supports access to the PKU register on GNU/Linux. The register is
364 added by the Memory Protection Keys for Userspace feature which will be
365 available in future Intel CPUs.
367 * GDB now supports C++11 rvalue references.
371 ** New functions to start, stop and access a running btrace recording.
372 ** Rvalue references are now supported in gdb.Type.
374 * GDB now supports recording and replaying rdrand and rdseed Intel 64
377 * Building GDB and GDBserver now requires a C++11 compiler.
379 For example, GCC 4.8 or later.
381 It is no longer possible to build GDB or GDBserver with a C
382 compiler. The --disable-build-with-cxx configure option has been
385 * Building GDB and GDBserver now requires GNU make >= 3.81.
387 It is no longer supported to build GDB or GDBserver with another
388 implementation of the make program or an earlier version of GNU make.
390 * Native debugging on MS-Windows supports command-line redirection
392 Command-line arguments used for starting programs on MS-Windows can
393 now include redirection symbols supported by native Windows shells,
394 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
395 as "run", "start", and "set args", as well as the corresponding MI
398 * Support for thread names on MS-Windows.
400 GDB now catches and handles the special exception that programs
401 running on MS-Windows use to assign names to threads in the
404 * Support for Java programs compiled with gcj has been removed.
406 * User commands now accept an unlimited number of arguments.
407 Previously, only up to 10 was accepted.
409 * The "eval" command now expands user-defined command arguments.
411 This makes it easier to process a variable number of arguments:
416 eval "print $arg%d", $i
421 * Target descriptions can now describe registers for sparc32 and sparc64.
423 * GDB now supports DWARF version 5 (debug information format).
424 Its .debug_names index is not yet supported.
426 * New native configurations
428 FreeBSD/mips mips*-*-freebsd
432 Synopsys ARC arc*-*-elf32
433 FreeBSD/mips mips*-*-freebsd
435 * Removed targets and native configurations
437 Alpha running FreeBSD alpha*-*-freebsd*
438 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
443 Erases all the flash memory regions reported by the target.
445 maint print arc arc-instruction address
446 Print internal disassembler information about instruction at a given address.
450 set disassembler-options
451 show disassembler-options
452 Controls the passing of target specific information to the disassembler.
453 If it is necessary to specify more than one disassembler option then
454 multiple options can be placed together into a comma separated list.
455 The default value is the empty string. Currently, the only supported
456 targets are ARM, PowerPC and S/390.
461 Erases all the flash memory regions reported by the target. This is
462 equivalent to the CLI command flash-erase.
464 -file-list-shared-libraries
465 List the shared libraries in the program. This is
466 equivalent to the CLI command "info shared".
469 Catchpoints stopping the program when Ada exceptions are
470 handled. This is equivalent to the CLI command "catch handlers".
472 *** Changes in GDB 7.12
474 * GDB and GDBserver now build with a C++ compiler by default.
476 The --enable-build-with-cxx configure option is now enabled by
477 default. One must now explicitly configure with
478 --disable-build-with-cxx in order to build with a C compiler. This
479 option will be removed in a future release.
481 * GDBserver now supports recording btrace without maintaining an active
484 * GDB now supports a negative repeat count in the 'x' command to examine
485 memory backward from the given address. For example:
488 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
489 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
490 (gdb) x/-5i 0x0000000000400580
491 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
492 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
493 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
494 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
495 0x40057b <main(int, char**)+25>:
496 callq 0x400536 <Func1(int, char const*)>
498 * Fortran: Support structures with fields of dynamic types and
499 arrays of dynamic types.
501 * The symbol dumping maintenance commands have new syntax.
502 maint print symbols [-pc address] [--] [filename]
503 maint print symbols [-objfile objfile] [-source source] [--] [filename]
504 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
505 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
506 maint print msymbols [-objfile objfile] [--] [filename]
508 * GDB now supports multibit bitfields and enums in target register
511 * New Python-based convenience function $_as_string(val), which returns
512 the textual representation of a value. This function is especially
513 useful to obtain the text label of an enum value.
515 * Intel MPX bound violation handling.
517 Segmentation faults caused by a Intel MPX boundary violation
518 now display the kind of violation (upper or lower), the memory
519 address accessed and the memory bounds, along with the usual
520 signal received and code location.
524 Program received signal SIGSEGV, Segmentation fault
525 Upper bound violation while accessing address 0x7fffffffc3b3
526 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
527 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
529 * Rust language support.
530 GDB now supports debugging programs written in the Rust programming
531 language. See https://www.rust-lang.org/ for more information about
534 * Support for running interpreters on specified input/output devices
536 GDB now supports a new mechanism that allows frontends to provide
537 fully featured GDB console views, as a better alternative to
538 building such views on top of the "-interpreter-exec console"
539 command. See the new "new-ui" command below. With that command,
540 frontends can now start GDB in the traditional command-line mode
541 running in an embedded terminal emulator widget, and create a
542 separate MI interpreter running on a specified i/o device. In this
543 way, GDB handles line editing, history, tab completion, etc. in the
544 console all by itself, and the GUI uses the separate MI interpreter
545 for its own control and synchronization, invisible to the command
548 * The "catch syscall" command catches groups of related syscalls.
550 The "catch syscall" command now supports catching a group of related
551 syscalls using the 'group:' or 'g:' prefix.
556 skip -gfile file-glob-pattern
557 skip -function function
558 skip -rfunction regular-expression
559 A generalized form of the skip command, with new support for
560 glob-style file names and regular expressions for function names.
561 Additionally, a file spec and a function spec may now be combined.
563 maint info line-table REGEXP
564 Display the contents of GDB's internal line table data struture.
567 Run any GDB unit tests that were compiled in.
570 Start a new user interface instance running INTERP as interpreter,
571 using the TTY file for input/output.
575 ** gdb.Breakpoint objects have a new attribute "pending", which
576 indicates whether the breakpoint is pending.
577 ** Three new breakpoint-related events have been added:
578 gdb.breakpoint_created, gdb.breakpoint_modified, and
579 gdb.breakpoint_deleted.
582 Signal ("set") the given MS-Windows event object. This is used in
583 conjunction with the Windows JIT debugging (AeDebug) support, where
584 the OS suspends a crashing process until a debugger can attach to
585 it. Resuming the crashing process, in order to debug it, is done by
588 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
589 was added in GDBserver, including JIT compiling fast tracepoint's
590 conditional expression bytecode into native code.
592 * Support for various remote target protocols and ROM monitors has
595 target m32rsdi Remote M32R debugging over SDI
596 target mips MIPS remote debugging protocol
597 target pmon PMON ROM monitor
598 target ddb NEC's DDB variant of PMON for Vr4300
599 target rockhopper NEC RockHopper variant of PMON
600 target lsi LSI variant of PMO
602 * Support for tracepoints and fast tracepoints on powerpc-linux,
603 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
604 including JIT compiling fast tracepoint's conditional expression
605 bytecode into native code.
607 * MI async record =record-started now includes the method and format used for
608 recording. For example:
610 =record-started,thread-group="i1",method="btrace",format="bts"
612 * MI async record =thread-selected now includes the frame field. For example:
614 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
618 Andes NDS32 nds32*-*-elf
620 *** Changes in GDB 7.11
622 * GDB now supports debugging kernel-based threads on FreeBSD.
624 * Per-inferior thread numbers
626 Thread numbers are now per inferior instead of global. If you're
627 debugging multiple inferiors, GDB displays thread IDs using a
628 qualified INF_NUM.THR_NUM form. For example:
632 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
633 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
634 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
635 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
637 As consequence, thread numbers as visible in the $_thread
638 convenience variable and in Python's InferiorThread.num attribute
639 are no longer unique between inferiors.
641 GDB now maintains a second thread ID per thread, referred to as the
642 global thread ID, which is the new equivalent of thread numbers in
643 previous releases. See also $_gthread below.
645 For backwards compatibility, MI's thread IDs always refer to global
648 * Commands that accept thread IDs now accept the qualified
649 INF_NUM.THR_NUM form as well. For example:
652 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
655 * In commands that accept a list of thread IDs, you can now refer to
656 all threads of an inferior using a star wildcard. GDB accepts
657 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
658 refer to all threads of the current inferior. For example, "info
661 * You can use "info threads -gid" to display the global thread ID of
664 * The new convenience variable $_gthread holds the global number of
667 * The new convenience variable $_inferior holds the number of the
670 * GDB now displays the ID and name of the thread that hit a breakpoint
671 or received a signal, if your program is multi-threaded. For
674 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
675 Thread 1 "main" received signal SIGINT, Interrupt.
677 * Record btrace now supports non-stop mode.
679 * Support for tracepoints on aarch64-linux was added in GDBserver.
681 * The 'record instruction-history' command now indicates speculative execution
682 when using the Intel Processor Trace recording format.
684 * GDB now allows users to specify explicit locations, bypassing
685 the linespec parser. This feature is also available to GDB/MI
688 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
689 GDB now is able to debug both AArch64 applications and ARM applications
692 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
693 including JIT compiling fast tracepoint's conditional expression bytecode
696 * GDB now supports displaced stepping on AArch64 GNU/Linux.
698 * "info threads", "info inferiors", "info display", "info checkpoints"
699 and "maint info program-spaces" now list the corresponding items in
700 ascending ID order, for consistency with all other "info" commands.
702 * In Ada, the overloads selection menu has been enhanced to display the
703 parameter types and the return types for the matching overloaded subprograms.
707 maint set target-non-stop (on|off|auto)
708 maint show target-non-stop
709 Control whether GDB targets always operate in non-stop mode even if
710 "set non-stop" is "off". The default is "auto", meaning non-stop
711 mode is enabled if supported by the target.
713 maint set bfd-sharing
714 maint show bfd-sharing
715 Control the reuse of bfd objects.
719 Control display of debugging info regarding bfd caching.
723 Control display of debugging info regarding FreeBSD threads.
725 set remote multiprocess-extensions-packet
726 show remote multiprocess-extensions-packet
727 Set/show the use of the remote protocol multiprocess extensions.
729 set remote thread-events
730 show remote thread-events
731 Set/show the use of thread create/exit events.
733 set ada print-signatures on|off
734 show ada print-signatures"
735 Control whether parameter types and return types are displayed in overloads
736 selection menus. It is activaled (@code{on}) by default.
740 Controls the maximum size of memory, in bytes, that GDB will
741 allocate for value contents. Prevents incorrect programs from
742 causing GDB to allocate overly large buffers. Default is 64k.
744 * The "disassemble" command accepts a new modifier: /s.
745 It prints mixed source+disassembly like /m with two differences:
746 - disassembled instructions are now printed in program order, and
747 - and source for all relevant files is now printed.
748 The "/m" option is now considered deprecated: its "source-centric"
749 output hasn't proved useful in practice.
751 * The "record instruction-history" command accepts a new modifier: /s.
752 It behaves exactly like /m and prints mixed source+disassembly.
754 * The "set scheduler-locking" command supports a new mode "replay".
755 It behaves like "off" in record mode and like "on" in replay mode.
757 * Support for various ROM monitors has been removed:
759 target dbug dBUG ROM monitor for Motorola ColdFire
760 target picobug Motorola picobug monitor
761 target dink32 DINK32 ROM monitor for PowerPC
762 target m32r Renesas M32R/D ROM monitor
763 target mon2000 mon2000 ROM monitor
764 target ppcbug PPCBUG ROM monitor for PowerPC
766 * Support for reading/writing memory and extracting values on architectures
767 whose memory is addressable in units of any integral multiple of 8 bits.
770 Allows to break when an Ada exception is handled.
775 Indicates that an exec system call was executed.
777 exec-events feature in qSupported
778 The qSupported packet allows GDB to request support for exec
779 events using the new 'gdbfeature' exec-event, and the qSupported
780 response can contain the corresponding 'stubfeature'. Set and
781 show commands can be used to display whether these features are enabled.
784 Equivalent to interrupting with the ^C character, but works in
787 thread created stop reason (T05 create:...)
788 Indicates that the thread was just created and is stopped at entry.
790 thread exit stop reply (w exitcode;tid)
791 Indicates that the thread has terminated.
794 Enables/disables thread create and exit event reporting. For
795 example, this is used in non-stop mode when GDB stops a set of
796 threads and synchronously waits for the their corresponding stop
797 replies. Without exit events, if one of the threads exits, GDB
798 would hang forever not knowing that it should no longer expect a
799 stop for that same thread.
802 Indicates that there are no resumed threads left in the target (all
803 threads are stopped). The remote stub reports support for this stop
804 reply to GDB's qSupported query.
807 Enables/disables catching syscalls from the inferior process.
808 The remote stub reports support for this packet to GDB's qSupported query.
810 syscall_entry stop reason
811 Indicates that a syscall was just called.
813 syscall_return stop reason
814 Indicates that a syscall just returned.
816 * Extended-remote exec events
818 ** GDB now has support for exec events on extended-remote Linux targets.
819 For such targets with Linux kernels 2.5.46 and later, this enables
820 follow-exec-mode and exec catchpoints.
822 set remote exec-event-feature-packet
823 show remote exec-event-feature-packet
824 Set/show the use of the remote exec event feature.
826 * Thread names in remote protocol
828 The reply to qXfer:threads:read may now include a name attribute for each
831 * Target remote mode fork and exec events
833 ** GDB now has support for fork and exec events on target remote mode
834 Linux targets. For such targets with Linux kernels 2.5.46 and later,
835 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
836 fork and exec catchpoints.
838 * Remote syscall events
840 ** GDB now has support for catch syscall on remote Linux targets,
841 currently enabled on x86/x86_64 architectures.
843 set remote catch-syscall-packet
844 show remote catch-syscall-packet
845 Set/show the use of the remote catch syscall feature.
849 ** The -var-set-format command now accepts the zero-hexadecimal
850 format. It outputs data in hexadecimal format with zero-padding on the
855 ** gdb.InferiorThread objects have a new attribute "global_num",
856 which refers to the thread's global thread ID. The existing
857 "num" attribute now refers to the thread's per-inferior number.
858 See "Per-inferior thread numbers" above.
859 ** gdb.InferiorThread objects have a new attribute "inferior", which
860 is the Inferior object the thread belongs to.
862 *** Changes in GDB 7.10
864 * Support for process record-replay and reverse debugging on aarch64*-linux*
865 targets has been added. GDB now supports recording of A64 instruction set
866 including advance SIMD instructions.
868 * Support for Sun's version of the "stabs" debug file format has been removed.
870 * GDB now honors the content of the file /proc/PID/coredump_filter
871 (PID is the process ID) on GNU/Linux systems. This file can be used
872 to specify the types of memory mappings that will be included in a
873 corefile. For more information, please refer to the manual page of
874 "core(5)". GDB also has a new command: "set use-coredump-filter
875 on|off". It allows to set whether GDB will read the content of the
876 /proc/PID/coredump_filter file when generating a corefile.
878 * The "info os" command on GNU/Linux can now display information on
880 "info os cpus" Listing of all cpus/cores on the system
882 * GDB has two new commands: "set serial parity odd|even|none" and
883 "show serial parity". These allows to set or show parity for the
886 * The "info source" command now displays the producer string if it was
887 present in the debug info. This typically includes the compiler version
888 and may include things like its command line arguments.
890 * The "info dll", an alias of the "info sharedlibrary" command,
891 is now available on all platforms.
893 * Directory names supplied to the "set sysroot" commands may be
894 prefixed with "target:" to tell GDB to access shared libraries from
895 the target system, be it local or remote. This replaces the prefix
896 "remote:". The default sysroot has been changed from "" to
897 "target:". "remote:" is automatically converted to "target:" for
898 backward compatibility.
900 * The system root specified by "set sysroot" will be prepended to the
901 filename of the main executable (if reported to GDB as absolute by
902 the operating system) when starting processes remotely, and when
903 attaching to already-running local or remote processes.
905 * GDB now supports automatic location and retrieval of executable
906 files from remote targets. Remote debugging can now be initiated
907 using only a "target remote" or "target extended-remote" command
908 (no "set sysroot" or "file" commands are required). See "New remote
911 * The "dump" command now supports verilog hex format.
913 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
915 * On GNU/Linux, GDB and gdbserver are now able to access executable
916 and shared library files without a "set sysroot" command when
917 attaching to processes running in different mount namespaces from
918 the debugger. This makes it possible to attach to processes in
919 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
920 See "New remote packets" below.
922 * The "tui reg" command now provides completion for all of the
923 available register groups, including target specific groups.
925 * The HISTSIZE environment variable is no longer read when determining
926 the size of GDB's command history. GDB now instead reads the dedicated
927 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
928 disables truncation of command history. Non-numeric values of GDBHISTSIZE
933 ** Memory ports can now be unbuffered.
937 ** gdb.Objfile objects have a new attribute "username",
938 which is the name of the objfile as specified by the user,
939 without, for example, resolving symlinks.
940 ** You can now write frame unwinders in Python.
941 ** gdb.Type objects have a new method "optimized_out",
942 returning optimized out gdb.Value instance of this type.
943 ** gdb.Value objects have new methods "reference_value" and
944 "const_value" which return a reference to the value and a
945 "const" version of the value respectively.
949 maint print symbol-cache
950 Print the contents of the symbol cache.
952 maint print symbol-cache-statistics
953 Print statistics of symbol cache usage.
955 maint flush-symbol-cache
956 Flush the contents of the symbol cache.
960 Start branch trace recording using Branch Trace Store (BTS) format.
963 Evaluate expression by using the compiler and print result.
967 Explicit commands for enabling and disabling tui mode.
970 set mpx bound on i386 and amd64
971 Support for bound table investigation on Intel MPX enabled applications.
975 Start branch trace recording using Intel Processor Trace format.
978 Print information about branch tracing internals.
980 maint btrace packet-history
981 Print the raw branch tracing data.
983 maint btrace clear-packet-history
984 Discard the stored raw branch tracing data.
987 Discard all branch tracing data. It will be fetched and processed
988 anew by the next "record" command.
993 Renamed from "set debug dwarf2-die".
995 Renamed from "show debug dwarf2-die".
998 Renamed from "set debug dwarf2-read".
999 show debug dwarf-read
1000 Renamed from "show debug dwarf2-read".
1002 maint set dwarf always-disassemble
1003 Renamed from "maint set dwarf2 always-disassemble".
1004 maint show dwarf always-disassemble
1005 Renamed from "maint show dwarf2 always-disassemble".
1007 maint set dwarf max-cache-age
1008 Renamed from "maint set dwarf2 max-cache-age".
1009 maint show dwarf max-cache-age
1010 Renamed from "maint show dwarf2 max-cache-age".
1012 set debug dwarf-line
1013 show debug dwarf-line
1014 Control display of debugging info regarding DWARF line processing.
1017 show max-completions
1018 Set the maximum number of candidates to be considered during
1019 completion. The default value is 200. This limit allows GDB
1020 to avoid generating large completion lists, the computation of
1021 which can cause the debugger to become temporarily unresponsive.
1023 set history remove-duplicates
1024 show history remove-duplicates
1025 Control the removal of duplicate history entries.
1027 maint set symbol-cache-size
1028 maint show symbol-cache-size
1029 Control the size of the symbol cache.
1031 set|show record btrace bts buffer-size
1032 Set and show the size of the ring buffer used for branch tracing in
1034 The obtained size may differ from the requested size. Use "info
1035 record" to see the obtained buffer size.
1037 set debug linux-namespaces
1038 show debug linux-namespaces
1039 Control display of debugging info regarding Linux namespaces.
1041 set|show record btrace pt buffer-size
1042 Set and show the size of the ring buffer used for branch tracing in
1043 Intel Processor Trace format.
1044 The obtained size may differ from the requested size. Use "info
1045 record" to see the obtained buffer size.
1047 maint set|show btrace pt skip-pad
1048 Set and show whether PAD packets are skipped when computing the
1051 * The command 'thread apply all' can now support new option '-ascending'
1052 to call its specified command for all threads in ascending order.
1054 * Python/Guile scripting
1056 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1057 special section named `.debug_gdb_scripts'.
1059 * New remote packets
1061 qXfer:btrace-conf:read
1062 Return the branch trace configuration for the current thread.
1064 Qbtrace-conf:bts:size
1065 Set the requested ring buffer size for branch tracing in BTS format.
1068 Enable Intel Procesor Trace-based branch tracing for the current
1069 process. The remote stub reports support for this packet to GDB's
1072 Qbtrace-conf:pt:size
1073 Set the requested ring buffer size for branch tracing in Intel Processor
1077 Indicates a memory breakpoint instruction was executed, irrespective
1078 of whether it was GDB that planted the breakpoint or the breakpoint
1079 is hardcoded in the program. This is required for correct non-stop
1083 Indicates the target stopped for a hardware breakpoint. This is
1084 required for correct non-stop mode operation.
1087 Return information about files on the remote system.
1089 qXfer:exec-file:read
1090 Return the full absolute name of the file that was executed to
1091 create a process running on the remote system.
1094 Select the filesystem on which vFile: operations with filename
1095 arguments will operate. This is required for GDB to be able to
1096 access files on remote targets where the remote stub does not
1097 share a common filesystem with the inferior(s).
1100 Indicates that a fork system call was executed.
1103 Indicates that a vfork system call was executed.
1105 vforkdone stop reason
1106 Indicates that a vfork child of the specified process has executed
1107 an exec or exit, allowing the vfork parent to resume execution.
1109 fork-events and vfork-events features in qSupported
1110 The qSupported packet allows GDB to request support for fork and
1111 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1112 and the qSupported response can contain the corresponding
1113 'stubfeatures'. Set and show commands can be used to display
1114 whether these features are enabled.
1116 * Extended-remote fork events
1118 ** GDB now has support for fork events on extended-remote Linux
1119 targets. For targets with Linux kernels 2.5.60 and later, this
1120 enables follow-fork-mode and detach-on-fork for both fork and
1121 vfork, as well as fork and vfork catchpoints.
1123 * The info record command now shows the recording format and the
1124 branch tracing configuration for the current thread when using
1125 the btrace record target.
1126 For the BTS format, it shows the ring buffer size.
1128 * GDB now has support for DTrace USDT (Userland Static Defined
1129 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1131 * GDB now supports access to vector registers on S/390 GNU/Linux
1134 * Removed command line options
1136 -xdb HP-UX XDB compatibility mode.
1138 * Removed targets and native configurations
1140 HP/PA running HP-UX hppa*-*-hpux*
1141 Itanium running HP-UX ia64-*-hpux*
1143 * New configure options
1146 This configure option allows the user to build GDB with support for
1147 Intel Processor Trace (default: auto). This requires libipt.
1149 --with-libipt-prefix=PATH
1150 Specify the path to the version of libipt that GDB should use.
1151 $PATH/include should contain the intel-pt.h header and
1152 $PATH/lib should contain the libipt.so library.
1154 *** Changes in GDB 7.9.1
1158 ** Xmethods can now specify a result type.
1160 *** Changes in GDB 7.9
1162 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1166 ** You can now access frame registers from Python scripts.
1167 ** New attribute 'producer' for gdb.Symtab objects.
1168 ** gdb.Objfile objects have a new attribute "progspace",
1169 which is the gdb.Progspace object of the containing program space.
1170 ** gdb.Objfile objects have a new attribute "owner".
1171 ** gdb.Objfile objects have a new attribute "build_id",
1172 which is the build ID generated when the file was built.
1173 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1174 ** A new event "gdb.clear_objfiles" has been added, triggered when
1175 selecting a new file to debug.
1176 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1177 ** New function gdb.lookup_objfile.
1179 New events which are triggered when GDB modifies the state of the
1182 ** gdb.events.inferior_call_pre: Function call is about to be made.
1183 ** gdb.events.inferior_call_post: Function call has just been made.
1184 ** gdb.events.memory_changed: A memory location has been altered.
1185 ** gdb.events.register_changed: A register has been altered.
1187 * New Python-based convenience functions:
1189 ** $_caller_is(name [, number_of_frames])
1190 ** $_caller_matches(regexp [, number_of_frames])
1191 ** $_any_caller_is(name [, number_of_frames])
1192 ** $_any_caller_matches(regexp [, number_of_frames])
1194 * GDB now supports the compilation and injection of source code into
1195 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1196 to compile the source code to object code, and if successful, inject
1197 and execute that code within the current context of the inferior.
1198 Currently the C language is supported. The commands used to
1199 interface with this new feature are:
1201 compile code [-raw|-r] [--] [source code]
1202 compile file [-raw|-r] filename
1206 demangle [-l language] [--] name
1207 Demangle "name" in the specified language, or the current language
1208 if elided. This command is renamed from the "maint demangle" command.
1209 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1210 as "maint demangler-warning".
1212 queue-signal signal-name-or-number
1213 Queue a signal to be delivered to the thread when it is resumed.
1215 add-auto-load-scripts-directory directory
1216 Add entries to the list of directories from which to load auto-loaded
1219 maint print user-registers
1220 List all currently available "user" registers.
1222 compile code [-r|-raw] [--] [source code]
1223 Compile, inject, and execute in the inferior the executable object
1224 code produced by compiling the provided source code.
1226 compile file [-r|-raw] filename
1227 Compile and inject into the inferior the executable object code
1228 produced by compiling the source code stored in the filename
1231 * On resume, GDB now always passes the signal the program had stopped
1232 for to the thread the signal was sent to, even if the user changed
1233 threads before resuming. Previously GDB would often (but not
1234 always) deliver the signal to the thread that happens to be current
1237 * Conversely, the "signal" command now consistently delivers the
1238 requested signal to the current thread. GDB now asks for
1239 confirmation if the program had stopped for a signal and the user
1240 switched threads meanwhile.
1242 * "breakpoint always-inserted" modes "off" and "auto" merged.
1244 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1245 won't remove breakpoints from the target until all threads stop,
1246 even in non-stop mode. The "auto" mode has been removed, and "off"
1247 is now the default mode.
1251 set debug symbol-lookup
1252 show debug symbol-lookup
1253 Control display of debugging info regarding symbol lookup.
1257 ** The -list-thread-groups command outputs an exit-code field for
1258 inferiors that have exited.
1262 MIPS SDE mips*-sde*-elf*
1266 Support for these obsolete configurations has been removed.
1268 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1269 SGI Irix-5.x mips-*-irix5*
1270 SGI Irix-6.x mips-*-irix6*
1271 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1272 VAX running Ultrix vax-*-ultrix*
1274 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1275 and "assf"), have been removed. Use the "sharedlibrary" command, or
1276 its alias "share", instead.
1278 *** Changes in GDB 7.8
1280 * New command line options
1283 This is an alias for the --data-directory option.
1285 * GDB supports printing and modifying of variable length automatic arrays
1286 as specified in ISO C99.
1288 * The ARM simulator now supports instruction level tracing
1289 with or without disassembly.
1293 GDB now has support for scripting using Guile. Whether this is
1294 available is determined at configure time.
1295 Guile version 2.0 or greater is required.
1296 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1298 * New commands (for set/show, see "New options" below)
1302 Invoke CODE by passing it to the Guile interpreter.
1306 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1308 info auto-load guile-scripts [regexp]
1309 Print the list of automatically loaded Guile scripts.
1311 * The source command is now capable of sourcing Guile scripts.
1312 This feature is dependent on the debugger being built with Guile support.
1316 set print symbol-loading (off|brief|full)
1317 show print symbol-loading
1318 Control whether to print informational messages when loading symbol
1319 information for a file. The default is "full", but when debugging
1320 programs with large numbers of shared libraries the amount of output
1321 becomes less useful.
1323 set guile print-stack (none|message|full)
1324 show guile print-stack
1325 Show a stack trace when an error is encountered in a Guile script.
1327 set auto-load guile-scripts (on|off)
1328 show auto-load guile-scripts
1329 Control auto-loading of Guile script files.
1331 maint ada set ignore-descriptive-types (on|off)
1332 maint ada show ignore-descriptive-types
1333 Control whether the debugger should ignore descriptive types in Ada
1334 programs. The default is not to ignore the descriptive types. See
1335 the user manual for more details on descriptive types and the intended
1336 usage of this option.
1338 set auto-connect-native-target
1340 Control whether GDB is allowed to automatically connect to the
1341 native target for the run, attach, etc. commands when not connected
1342 to any target yet. See also "target native" below.
1344 set record btrace replay-memory-access (read-only|read-write)
1345 show record btrace replay-memory-access
1346 Control what memory accesses are allowed during replay.
1348 maint set target-async (on|off)
1349 maint show target-async
1350 This controls whether GDB targets operate in synchronous or
1351 asynchronous mode. Normally the default is asynchronous, if it is
1352 available; but this can be changed to more easily debug problems
1353 occurring only in synchronous mode.
1355 set mi-async (on|off)
1357 Control whether MI asynchronous mode is preferred. This supersedes
1358 "set target-async" of previous GDB versions.
1360 * "set target-async" is deprecated as a CLI option and is now an alias
1361 for "set mi-async" (only puts MI into async mode).
1363 * Background execution commands (e.g., "c&", "s&", etc.) are now
1364 possible ``out of the box'' if the target supports them. Previously
1365 the user would need to explicitly enable the possibility with the
1366 "set target-async on" command.
1368 * New features in the GDB remote stub, GDBserver
1370 ** New option --debug-format=option1[,option2,...] allows one to add
1371 additional text to each output. At present only timestamps
1372 are supported: --debug-format=timestamps.
1373 Timestamps can also be turned on with the
1374 "monitor set debug-format timestamps" command from GDB.
1376 * The 'record instruction-history' command now starts counting instructions
1377 at one. This also affects the instruction ranges reported by the
1378 'record function-call-history' command when given the /i modifier.
1380 * The command 'record function-call-history' supports a new modifier '/c' to
1381 indent the function names based on their call stack depth.
1382 The fields for the '/i' and '/l' modifier have been reordered.
1383 The source line range is now prefixed with 'at'.
1384 The instruction range is now prefixed with 'inst'.
1385 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1386 "record instruction-history" and "list" commands.
1388 * The ranges given as arguments to the 'record function-call-history' and
1389 'record instruction-history' commands are now inclusive.
1391 * The btrace record target now supports the 'record goto' command.
1392 For locations inside the execution trace, the back trace is computed
1393 based on the information stored in the execution trace.
1395 * The btrace record target supports limited reverse execution and replay.
1396 The target does not record data and therefore does not allow reading
1397 memory or registers.
1399 * The "catch syscall" command now works on s390*-linux* targets.
1401 * The "compare-sections" command is no longer specific to target
1402 remote. It now works with all targets.
1404 * All native targets are now consistently called "native".
1405 Consequently, the "target child", "target GNU", "target djgpp",
1406 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1407 commands have been replaced with "target native". The QNX/NTO port
1408 leaves the "procfs" target in place and adds a "native" target for
1409 consistency with other ports. The impact on users should be minimal
1410 as these commands previously either throwed an error, or were
1411 no-ops. The target's name is visible in the output of the following
1412 commands: "help target", "info target", "info files", "maint print
1415 * The "target native" command now connects to the native target. This
1416 can be used to launch native programs even when "set
1417 auto-connect-native-target" is set to off.
1419 * GDB now supports access to Intel MPX registers on GNU/Linux.
1421 * Support for Intel AVX-512 registers on GNU/Linux.
1422 Support displaying and modifying Intel AVX-512 registers
1423 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1425 * New remote packets
1427 qXfer:btrace:read's annex
1428 The qXfer:btrace:read packet supports a new annex 'delta' to read
1429 branch trace incrementally.
1433 ** Valid Python operations on gdb.Value objects representing
1434 structs/classes invoke the corresponding overloaded operators if
1436 ** New `Xmethods' feature in the Python API. Xmethods are
1437 additional methods or replacements for existing methods of a C++
1438 class. This feature is useful for those cases where a method
1439 defined in C++ source code could be inlined or optimized out by
1440 the compiler, making it unavailable to GDB.
1443 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1445 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1446 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1447 its alias "share", instead.
1449 * The commands "set remotebaud" and "show remotebaud" are no longer
1450 supported. Use "set serial baud" and "show serial baud" (respectively)
1455 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1456 target-async". The latter is left as a deprecated alias of the
1457 former for backward compatibility. If the target supports it,
1458 CLI background execution commands are now always possible by
1459 default, independently of whether the frontend stated a
1460 preference for asynchronous execution with "-gdb-set mi-async".
1461 Previously "-gdb-set target-async off" affected both MI execution
1462 commands and CLI execution commands.
1464 *** Changes in GDB 7.7
1466 * Improved support for process record-replay and reverse debugging on
1467 arm*-linux* targets. Support for thumb32 and syscall instruction
1468 recording has been added.
1470 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1472 * GDB now supports Fission DWP file format version 2.
1473 http://gcc.gnu.org/wiki/DebugFission
1475 * New convenience function "$_isvoid", to check whether an expression
1476 is void. A void expression is an expression where the type of the
1477 result is "void". For example, some convenience variables may be
1478 "void" when evaluated (e.g., "$_exitcode" before the execution of
1479 the program being debugged; or an undefined convenience variable).
1480 Another example, when calling a function whose return type is
1483 * The "maintenance print objfiles" command now takes an optional regexp.
1485 * The "catch syscall" command now works on arm*-linux* targets.
1487 * GDB now consistently shows "<not saved>" when printing values of
1488 registers the debug info indicates have not been saved in the frame
1489 and there's nowhere to retrieve them from
1490 (callee-saved/call-clobbered registers):
1495 (gdb) info registers rax
1498 Before, the former would print "<optimized out>", and the latter
1499 "*value not available*".
1501 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1506 ** Frame filters and frame decorators have been added.
1507 ** Temporary breakpoints are now supported.
1508 ** Line tables representation has been added.
1509 ** New attribute 'parent_type' for gdb.Field objects.
1510 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1511 ** New attribute 'name' for gdb.Type objects.
1515 Nios II ELF nios2*-*-elf
1516 Nios II GNU/Linux nios2*-*-linux
1517 Texas Instruments MSP430 msp430*-*-elf
1519 * Removed native configurations
1521 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1522 been removed. ELF variants of these configurations are kept supported.
1524 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1525 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1526 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1527 i[34567]86-*-openbsd3.[0-3]
1528 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1529 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1530 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1534 Like "catch throw", but catches a re-thrown exception.
1535 maint check-psymtabs
1536 Renamed from old "maint check-symtabs".
1538 Perform consistency checks on symtabs.
1539 maint expand-symtabs
1540 Expand symtabs matching an optional regexp.
1543 Display the details of GDB configure-time options.
1545 maint set|show per-command
1546 maint set|show per-command space
1547 maint set|show per-command time
1548 maint set|show per-command symtab
1549 Enable display of per-command gdb resource usage.
1551 remove-symbol-file FILENAME
1552 remove-symbol-file -a ADDRESS
1553 Remove a symbol file added via add-symbol-file. The file to remove
1554 can be identified by its filename or by an address that lies within
1555 the boundaries of this symbol file in memory.
1558 info exceptions REGEXP
1559 Display the list of Ada exceptions defined in the program being
1560 debugged. If provided, only the exceptions whose names match REGEXP
1565 set debug symfile off|on
1567 Control display of debugging info regarding reading symbol files and
1568 symbol tables within those files
1570 set print raw frame-arguments
1571 show print raw frame-arguments
1572 Set/show whether to print frame arguments in raw mode,
1573 disregarding any defined pretty-printers.
1575 set remote trace-status-packet
1576 show remote trace-status-packet
1577 Set/show the use of remote protocol qTStatus packet.
1581 Control display of debugging messages related to Nios II targets.
1585 Control whether target-assisted range stepping is enabled.
1587 set startup-with-shell
1588 show startup-with-shell
1589 Specifies whether Unix child processes are started via a shell or
1594 Use the target memory cache for accesses to the code segment. This
1595 improves performance of remote debugging (particularly disassembly).
1597 * You can now use a literal value 'unlimited' for options that
1598 interpret 0 or -1 as meaning "unlimited". E.g., "set
1599 trace-buffer-size unlimited" is now an alias for "set
1600 trace-buffer-size -1" and "set height unlimited" is now an alias for
1603 * The "set debug symtab-create" debugging option of GDB has been changed to
1604 accept a verbosity level. 0 means "off", 1 provides basic debugging
1605 output, and values of 2 or greater provides more verbose output.
1607 * New command-line options
1609 Display the details of GDB configure-time options.
1611 * The command 'tsave' can now support new option '-ctf' to save trace
1612 buffer in Common Trace Format.
1614 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1617 * GDB now implements the the C++ 'typeid' operator.
1619 * The new convenience variable $_exception holds the exception being
1620 thrown or caught at an exception-related catchpoint.
1622 * The exception-related catchpoints, like "catch throw", now accept a
1623 regular expression which can be used to filter exceptions by type.
1625 * The new convenience variable $_exitsignal is automatically set to
1626 the terminating signal number when the program being debugged dies
1627 due to an uncaught signal.
1631 ** All MI commands now accept an optional "--language" option.
1632 Support for this feature can be verified by using the "-list-features"
1633 command, which should contain "language-option".
1635 ** The new command -info-gdb-mi-command allows the user to determine
1636 whether a GDB/MI command is supported or not.
1638 ** The "^error" result record returned when trying to execute an undefined
1639 GDB/MI command now provides a variable named "code" whose content is the
1640 "undefined-command" error code. Support for this feature can be verified
1641 by using the "-list-features" command, which should contain
1642 "undefined-command-error-code".
1644 ** The -trace-save MI command can optionally save trace buffer in Common
1647 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1649 ** The command -data-list-register-values now accepts an optional
1650 "--skip-unavailable" option. When used, only the available registers
1653 ** The new command -trace-frame-collected dumps collected variables,
1654 computed expressions, tvars, memory and registers in a traceframe.
1656 ** The commands -stack-list-locals, -stack-list-arguments and
1657 -stack-list-variables now accept an option "--skip-unavailable".
1658 When used, only the available locals or arguments are displayed.
1660 ** The -exec-run command now accepts an optional "--start" option.
1661 When used, the command follows the same semantics as the "start"
1662 command, stopping the program's execution at the start of its
1663 main subprogram. Support for this feature can be verified using
1664 the "-list-features" command, which should contain
1665 "exec-run-start-option".
1667 ** The new commands -catch-assert and -catch-exceptions insert
1668 catchpoints stopping the program when Ada exceptions are raised.
1670 ** The new command -info-ada-exceptions provides the equivalent of
1671 the new "info exceptions" command.
1673 * New system-wide configuration scripts
1674 A GDB installation now provides scripts suitable for use as system-wide
1675 configuration scripts for the following systems:
1679 * GDB now supports target-assigned range stepping with remote targets.
1680 This improves the performance of stepping source lines by reducing
1681 the number of control packets from/to GDB. See "New remote packets"
1684 * GDB now understands the element 'tvar' in the XML traceframe info.
1685 It has the id of the collected trace state variables.
1687 * On S/390 targets that provide the transactional-execution feature,
1688 the program interruption transaction diagnostic block (TDB) is now
1689 represented as a number of additional "registers" in GDB.
1691 * New remote packets
1695 The vCont packet supports a new 'r' action, that tells the remote
1696 stub to step through an address range itself, without GDB
1697 involvemement at each single-step.
1699 qXfer:libraries-svr4:read's annex
1700 The previously unused annex of the qXfer:libraries-svr4:read packet
1701 is now used to support passing an argument list. The remote stub
1702 reports support for this argument list to GDB's qSupported query.
1703 The defined arguments are "start" and "prev", used to reduce work
1704 necessary for library list updating, resulting in significant
1707 * New features in the GDB remote stub, GDBserver
1709 ** GDBserver now supports target-assisted range stepping. Currently
1710 enabled on x86/x86_64 GNU/Linux targets.
1712 ** GDBserver now adds element 'tvar' in the XML in the reply to
1713 'qXfer:traceframe-info:read'. It has the id of the collected
1714 trace state variables.
1716 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1719 * New 'z' formatter for printing and examining memory, this displays the
1720 value as hexadecimal zero padded on the left to the size of the type.
1722 * GDB can now use Windows x64 unwinding data.
1724 * The "set remotebaud" command has been replaced by "set serial baud".
1725 Similarly, "show remotebaud" has been replaced by "show serial baud".
1726 The "set remotebaud" and "show remotebaud" commands are still available
1727 to provide backward compatibility with older versions of GDB.
1729 *** Changes in GDB 7.6
1731 * Target record has been renamed to record-full.
1732 Record/replay is now enabled with the "record full" command.
1733 This also affects settings that are associated with full record/replay
1734 that have been moved from "set/show record" to "set/show record full":
1736 set|show record full insn-number-max
1737 set|show record full stop-at-limit
1738 set|show record full memory-query
1740 * A new record target "record-btrace" has been added. The new target
1741 uses hardware support to record the control-flow of a process. It
1742 does not support replaying the execution, but it implements the
1743 below new commands for investigating the recorded execution log.
1744 This new recording method can be enabled using:
1748 The "record-btrace" target is only available on Intel Atom processors
1749 and requires a Linux kernel 2.6.32 or later.
1751 * Two new commands have been added for record/replay to give information
1752 about the recorded execution without having to replay the execution.
1753 The commands are only supported by "record btrace".
1755 record instruction-history prints the execution history at
1756 instruction granularity
1758 record function-call-history prints the execution history at
1759 function granularity
1761 * New native configurations
1763 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1764 FreeBSD/powerpc powerpc*-*-freebsd
1765 x86_64/Cygwin x86_64-*-cygwin*
1766 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1770 ARM AArch64 aarch64*-*-elf
1771 ARM AArch64 GNU/Linux aarch64*-*-linux
1772 Lynx 178 PowerPC powerpc-*-lynx*178
1773 x86_64/Cygwin x86_64-*-cygwin*
1774 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1776 * If the configured location of system.gdbinit file (as given by the
1777 --with-system-gdbinit option at configure time) is in the
1778 data-directory (as specified by --with-gdb-datadir at configure
1779 time) or in one of its subdirectories, then GDB will look for the
1780 system-wide init file in the directory specified by the
1781 --data-directory command-line option.
1783 * New command line options:
1785 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1786 other initialization files, unlike -nx which disables all of them.
1788 * Removed command line options
1790 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1793 * The 'ptype' and 'whatis' commands now accept an argument to control
1796 * 'info proc' now works on some core files.
1800 ** Vectors can be created with gdb.Type.vector.
1802 ** Python's atexit.register now works in GDB.
1804 ** Types can be pretty-printed via a Python API.
1806 ** Python 3 is now supported (in addition to Python 2.4 or later)
1808 ** New class gdb.Architecture exposes GDB's internal representation
1809 of architecture in the Python API.
1811 ** New method Frame.architecture returns the gdb.Architecture object
1812 corresponding to the frame's architecture.
1814 * New Python-based convenience functions:
1816 ** $_memeq(buf1, buf2, length)
1817 ** $_streq(str1, str2)
1819 ** $_regex(str, regex)
1821 * The 'cd' command now defaults to using '~' (the home directory) if not
1824 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1825 default for GCC since November 2000.
1827 * The command 'forward-search' can now be abbreviated as 'fo'.
1829 * The command 'info tracepoints' can now display 'installed on target'
1830 or 'not installed on target' for each non-pending location of tracepoint.
1832 * New configure options
1834 --enable-libmcheck/--disable-libmcheck
1835 By default, development versions are built with -lmcheck on hosts
1836 that support it, in order to help track memory corruption issues.
1837 Release versions, on the other hand, are built without -lmcheck
1838 by default. The --enable-libmcheck/--disable-libmcheck configure
1839 options allow the user to override that default.
1840 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1841 This configure option allows the user to build GDB with
1842 libbabeltrace using which GDB can read Common Trace Format data.
1844 * New commands (for set/show, see "New options" below)
1847 Catch signals. This is similar to "handle", but allows commands and
1848 conditions to be attached.
1851 List the BFDs known to GDB.
1853 python-interactive [command]
1855 Start a Python interactive prompt, or evaluate the optional command
1856 and print the result of expressions.
1859 "py" is a new alias for "python".
1861 enable type-printer [name]...
1862 disable type-printer [name]...
1863 Enable or disable type printers.
1867 ** For the Renesas Super-H architecture, the "regs" command has been removed
1868 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1873 set print type methods (on|off)
1874 show print type methods
1875 Control whether method declarations are displayed by "ptype".
1876 The default is to show them.
1878 set print type typedefs (on|off)
1879 show print type typedefs
1880 Control whether typedef definitions are displayed by "ptype".
1881 The default is to show them.
1883 set filename-display basename|relative|absolute
1884 show filename-display
1885 Control the way in which filenames is displayed.
1886 The default is "relative", which preserves previous behavior.
1888 set trace-buffer-size
1889 show trace-buffer-size
1890 Request target to change the size of trace buffer.
1892 set remote trace-buffer-size-packet auto|on|off
1893 show remote trace-buffer-size-packet
1894 Control the use of the remote protocol `QTBuffer:size' packet.
1898 Control display of debugging messages related to ARM AArch64.
1901 set debug coff-pe-read
1902 show debug coff-pe-read
1903 Control display of debugging messages related to reading of COFF/PE
1908 Control display of debugging messages related to Mach-O symbols
1911 set debug notification
1912 show debug notification
1913 Control display of debugging info for async remote notification.
1917 ** Command parameter changes are now notified using new async record
1918 "=cmd-param-changed".
1919 ** Trace frame changes caused by command "tfind" are now notified using
1920 new async record "=traceframe-changed".
1921 ** The creation, deletion and modification of trace state variables
1922 are now notified using new async records "=tsv-created",
1923 "=tsv-deleted" and "=tsv-modified".
1924 ** The start and stop of process record are now notified using new
1925 async record "=record-started" and "=record-stopped".
1926 ** Memory changes are now notified using new async record
1928 ** The data-disassemble command response will include a "fullname" field
1929 containing the absolute file name when source has been requested.
1930 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1931 command, to allow pattern filling of memory areas.
1932 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1933 library load/unload events.
1934 ** The response to breakpoint commands and breakpoint async records
1935 includes an "installed" field containing a boolean state about each
1936 non-pending tracepoint location is whether installed on target or not.
1937 ** Output of the "-trace-status" command includes a "trace-file" field
1938 containing the name of the trace file being examined. This field is
1939 optional, and only present when examining a trace file.
1940 ** The "fullname" field is now always present along with the "file" field,
1941 even if the file cannot be found by GDB.
1943 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1944 You must have the LZMA library available when configuring GDB for this
1945 feature to be enabled. For more information, see:
1946 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1948 * New remote packets
1951 Set the size of trace buffer. The remote stub reports support for this
1952 packet to gdb's qSupported query.
1955 Enable Branch Trace Store (BTS)-based branch tracing for the current
1956 thread. The remote stub reports support for this packet to gdb's
1960 Disable branch tracing for the current thread. The remote stub reports
1961 support for this packet to gdb's qSupported query.
1964 Read the traced branches for the current thread. The remote stub
1965 reports support for this packet to gdb's qSupported query.
1967 *** Changes in GDB 7.5
1969 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1970 for more x32 ABI info.
1972 * GDB now supports access to MIPS DSP registers on Linux targets.
1974 * GDB now supports debugging microMIPS binaries.
1976 * The "info os" command on GNU/Linux can now display information on
1977 several new classes of objects managed by the operating system:
1978 "info os procgroups" lists process groups
1979 "info os files" lists file descriptors
1980 "info os sockets" lists internet-domain sockets
1981 "info os shm" lists shared-memory regions
1982 "info os semaphores" lists semaphores
1983 "info os msg" lists message queues
1984 "info os modules" lists loaded kernel modules
1986 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1987 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1988 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1989 options and inspect the probe arguments using the new $_probe_arg family
1990 of convenience variables. You can obtain more information about SystemTap
1991 in <http://sourceware.org/systemtap/>.
1993 * GDB now supports reversible debugging on ARM, it allows you to
1994 debug basic ARM and THUMB instructions, and provides
1995 record/replay support.
1997 * The option "symbol-reloading" has been deleted as it is no longer used.
2001 ** GDB commands implemented in Python can now be put in command class
2004 ** The "maint set python print-stack on|off" is now deleted.
2006 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2007 apply "flag enum"-style pretty-printing to any enum.
2009 ** gdb.lookup_symbol can now work when there is no current frame.
2011 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2012 the source at which the symbol was defined.
2014 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2015 method 'value'. The former indicates whether the symbol needs a
2016 frame in order to compute its value, and the latter computes the
2019 ** A new method 'referenced_value' on gdb.Value objects which can
2020 dereference pointer as well as C++ reference values.
2022 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2023 which return the global and static blocks (as gdb.Block objects),
2024 of the underlying symbol table, respectively.
2026 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2027 object associated with a PC value.
2029 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2030 of the address range occupied by code for the current source line.
2032 * Go language support.
2033 GDB now supports debugging programs written in the Go programming
2036 * GDBserver now supports stdio connections.
2037 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2039 * The binary "gdbtui" can no longer be built or installed.
2040 Use "gdb -tui" instead.
2042 * GDB will now print "flag" enums specially. A flag enum is one where
2043 all the enumerator values have no bits in common when pairwise
2044 "and"ed. When printing a value whose type is a flag enum, GDB will
2045 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2046 (gdb) print (enum E) 3
2049 * The filename part of a linespec will now match trailing components
2050 of a source file name. For example, "break gcc/expr.c:1000" will
2051 now set a breakpoint in build/gcc/expr.c, but not
2052 build/libcpp/expr.c.
2054 * The "info proc" and "generate-core-file" commands will now also
2055 work on remote targets connected to GDBserver on Linux.
2057 * The command "info catch" has been removed. It has been disabled
2058 since December 2007.
2060 * The "catch exception" and "catch assert" commands now accept
2061 a condition at the end of the command, much like the "break"
2062 command does. For instance:
2064 (gdb) catch exception Constraint_Error if Barrier = True
2066 Previously, it was possible to add a condition to such catchpoints,
2067 but it had to be done as a second step, after the catchpoint had been
2068 created, using the "condition" command.
2070 * The "info static-tracepoint-marker" command will now also work on
2071 native Linux targets with in-process agent.
2073 * GDB can now set breakpoints on inlined functions.
2075 * The .gdb_index section has been updated to include symbols for
2076 inlined functions. GDB will ignore older .gdb_index sections by
2077 default, which could cause symbol files to be loaded more slowly
2078 until their .gdb_index sections can be recreated. The new command
2079 "set use-deprecated-index-sections on" will cause GDB to use any older
2080 .gdb_index sections it finds. This will restore performance, but the
2081 ability to set breakpoints on inlined functions will be lost in symbol
2082 files with older .gdb_index sections.
2084 The .gdb_index section has also been updated to record more information
2085 about each symbol. This speeds up the "info variables", "info functions"
2086 and "info types" commands when used with programs having the .gdb_index
2087 section, as well as speeding up debugging with shared libraries using
2088 the .gdb_index section.
2090 * Ada support for GDB/MI Variable Objects has been added.
2092 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2097 ** New command -info-os is the MI equivalent of "info os".
2099 ** Output logs ("set logging" and related) now include MI output.
2103 ** "set use-deprecated-index-sections on|off"
2104 "show use-deprecated-index-sections on|off"
2105 Controls the use of deprecated .gdb_index sections.
2107 ** "catch load" and "catch unload" can be used to stop when a shared
2108 library is loaded or unloaded, respectively.
2110 ** "enable count" can be used to auto-disable a breakpoint after
2113 ** "info vtbl" can be used to show the virtual method tables for
2114 C++ and Java objects.
2116 ** "explore" and its sub commands "explore value" and "explore type"
2117 can be used to recursively explore values and types of
2118 expressions. These commands are available only if GDB is
2119 configured with '--with-python'.
2121 ** "info auto-load" shows status of all kinds of auto-loaded files,
2122 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2123 sequences of commands files, "info auto-load python-scripts"
2124 shows status of auto-loading Python script files,
2125 "info auto-load local-gdbinit" shows status of loading init file
2126 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2127 status of inferior specific thread debugging shared library loading.
2129 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2130 and "show auto-load-scripts" commands have been deprecated, use their
2131 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2132 and "show auto-load python-scripts" counterparts instead.
2134 ** "dprintf location,format,args..." creates a dynamic printf, which
2135 is basically a breakpoint that does a printf and immediately
2136 resumes your program's execution, so it is like a printf that you
2137 can insert dynamically at runtime instead of at compiletime.
2139 ** "set print symbol"
2141 Controls whether GDB attempts to display the symbol, if any,
2142 corresponding to addresses it prints. This defaults to "on", but
2143 you can set it to "off" to restore GDB's previous behavior.
2145 * Deprecated commands
2147 ** For the Renesas Super-H architecture, the "regs" command has been
2148 deprecated, and "info all-registers" should be used instead.
2152 Renesas RL78 rl78-*-elf
2153 HP OpenVMS ia64 ia64-hp-openvms*
2155 * GDBserver supports evaluation of breakpoint conditions. When
2156 support is advertised by GDBserver, GDB may be told to send the
2157 breakpoint conditions in bytecode form to GDBserver. GDBserver
2158 will only report the breakpoint trigger to GDB when its condition
2163 set mips compression
2164 show mips compression
2165 Select the compressed ISA encoding used in functions that have no symbol
2166 information available. The encoding can be set to either of:
2169 and is updated automatically from ELF file flags if available.
2171 set breakpoint condition-evaluation
2172 show breakpoint condition-evaluation
2173 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2174 GDBserver ("target"). Default option "auto" chooses the most efficient
2176 This option can improve debugger efficiency depending on the speed of the
2180 Disable auto-loading globally.
2183 Show auto-loading setting of all kinds of auto-loaded files.
2185 set auto-load gdb-scripts on|off
2186 show auto-load gdb-scripts
2187 Control auto-loading of GDB canned sequences of commands files.
2189 set auto-load python-scripts on|off
2190 show auto-load python-scripts
2191 Control auto-loading of Python script files.
2193 set auto-load local-gdbinit on|off
2194 show auto-load local-gdbinit
2195 Control loading of init file (.gdbinit) from current directory.
2197 set auto-load libthread-db on|off
2198 show auto-load libthread-db
2199 Control auto-loading of inferior specific thread debugging shared library.
2201 set auto-load scripts-directory <dir1>[:<dir2>...]
2202 show auto-load scripts-directory
2203 Set a list of directories from which to load auto-loaded scripts.
2204 Automatically loaded Python scripts and GDB scripts are located in one
2205 of the directories listed by this option.
2206 The delimiter (':' above) may differ according to the host platform.
2208 set auto-load safe-path <dir1>[:<dir2>...]
2209 show auto-load safe-path
2210 Set a list of directories from which it is safe to auto-load files.
2211 The delimiter (':' above) may differ according to the host platform.
2213 set debug auto-load on|off
2214 show debug auto-load
2215 Control display of debugging info for auto-loading the files above.
2217 set dprintf-style gdb|call|agent
2219 Control the way in which a dynamic printf is performed; "gdb"
2220 requests a GDB printf command, while "call" causes dprintf to call a
2221 function in the inferior. "agent" requests that the target agent
2222 (such as GDBserver) do the printing.
2224 set dprintf-function <expr>
2225 show dprintf-function
2226 set dprintf-channel <expr>
2227 show dprintf-channel
2228 Set the function and optional first argument to the call when using
2229 the "call" style of dynamic printf.
2231 set disconnected-dprintf on|off
2232 show disconnected-dprintf
2233 Control whether agent-style dynamic printfs continue to be in effect
2234 after GDB disconnects.
2236 * New configure options
2238 --with-auto-load-dir
2239 Configure default value for the 'set auto-load scripts-directory'
2240 setting above. It defaults to '$debugdir:$datadir/auto-load',
2241 $debugdir representing global debugging info directories (available
2242 via 'show debug-file-directory') and $datadir representing GDB's data
2243 directory (available via 'show data-directory').
2245 --with-auto-load-safe-path
2246 Configure default value for the 'set auto-load safe-path' setting
2247 above. It defaults to the --with-auto-load-dir setting.
2249 --without-auto-load-safe-path
2250 Set 'set auto-load safe-path' to '/', effectively disabling this
2253 * New remote packets
2255 z0/z1 conditional breakpoints extension
2257 The z0/z1 breakpoint insertion packets have been extended to carry
2258 a list of conditional expressions over to the remote stub depending on the
2259 condition evaluation mode. The use of this extension can be controlled
2260 via the "set remote conditional-breakpoints-packet" command.
2264 Specify the signals which the remote stub may pass to the debugged
2265 program without GDB involvement.
2267 * New command line options
2269 --init-command=FILE, -ix Like --command, -x but execute it
2270 before loading inferior.
2271 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2272 execute it before loading inferior.
2274 *** Changes in GDB 7.4
2276 * GDB now handles ambiguous linespecs more consistently; the existing
2277 FILE:LINE support has been expanded to other types of linespecs. A
2278 breakpoint will now be set on all matching locations in all
2279 inferiors, and locations will be added or removed according to
2282 * GDB now allows you to skip uninteresting functions and files when
2283 stepping with the "skip function" and "skip file" commands.
2285 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2286 and "show remote hardware-watchpoint-length-limit". These allows to
2287 set or show the maximum length limit (in bytes) of a remote
2288 target hardware watchpoint.
2290 This allows e.g. to use "unlimited" hardware watchpoints with the
2291 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2292 watchpoints are slower than real hardware watchpoints but are
2293 significantly faster than gdb software watchpoints.
2297 ** The register_pretty_printer function in module gdb.printing now takes
2298 an optional `replace' argument. If True, the new printer replaces any
2301 ** The "maint set python print-stack on|off" command has been
2302 deprecated and will be deleted in GDB 7.5.
2303 A new command: "set python print-stack none|full|message" has
2304 replaced it. Additionally, the default for "print-stack" is
2305 now "message", which just prints the error message without
2308 ** A prompt substitution hook (prompt_hook) is now available to the
2311 ** A new Python module, gdb.prompt has been added to the GDB Python
2312 modules library. This module provides functionality for
2313 escape sequences in prompts (used by set/show
2314 extended-prompt). These escape sequences are replaced by their
2315 corresponding value.
2317 ** Python commands and convenience-functions located in
2318 'data-directory'/python/gdb/command and
2319 'data-directory'/python/gdb/function are now automatically loaded
2322 ** Blocks now provide four new attributes. global_block and
2323 static_block will return the global and static blocks
2324 respectively. is_static and is_global are boolean attributes
2325 that indicate if the block is one of those two types.
2327 ** Symbols now provide the "type" attribute, the type of the symbol.
2329 ** The "gdb.breakpoint" function has been deprecated in favor of
2332 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2333 of a function. This class is based on the "finish" command
2334 available in the CLI.
2336 ** Type objects for struct and union types now allow access to
2337 the fields using standard Python dictionary (mapping) methods.
2338 For example, "some_type['myfield']" now works, as does
2339 "some_type.items()".
2341 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2344 ** A new function, "deep_items" has been added to the gdb.types
2345 module in the GDB Python modules library. This function returns
2346 an iterator over the fields of a struct or union type. Unlike
2347 the standard Python "iteritems" method, it will recursively traverse
2348 any anonymous fields.
2352 ** "*stopped" events can report several new "reason"s, such as
2355 ** Breakpoint changes are now notified using new async records, like
2356 "=breakpoint-modified".
2358 ** New command -ada-task-info.
2360 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2361 $sdir specifies the default system locations of shared libraries.
2362 $pdir specifies the directory where the libpthread used by the application
2365 GDB no longer looks in $sdir and $pdir after it has searched the directories
2366 mentioned in libthread-db-search-path. If you want to search those
2367 directories, they must be specified in libthread-db-search-path.
2368 The default value of libthread-db-search-path on GNU/Linux and Solaris
2369 systems is now "$sdir:$pdir".
2371 $pdir is not supported by gdbserver, it is currently ignored.
2372 $sdir is supported by gdbserver.
2374 * New configure option --with-iconv-bin.
2375 When using the internationalization support like the one in the GNU C
2376 library, GDB will invoke the "iconv" program to get a list of supported
2377 character sets. If this program lives in a non-standard location, one can
2378 use this option to specify where to find it.
2380 * When natively debugging programs on PowerPC BookE processors running
2381 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2382 watchpoints, which specify a mask in addition to an address to watch.
2383 The mask specifies that some bits of an address (the bits which are
2384 reset in the mask) should be ignored when matching the address accessed
2385 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2386 section in the user manual for more details.
2388 * The new option --once causes GDBserver to stop listening for connections once
2389 the first connection is made. The listening port used by GDBserver will
2390 become available after that.
2392 * New commands "info macros" and "alias" have been added.
2394 * New function parameters suffix @entry specifies value of function parameter
2395 at the time the function got called. Entry values are available only since
2401 "!" is now an alias of the "shell" command.
2402 Note that no space is needed between "!" and SHELL COMMAND.
2406 watch EXPRESSION mask MASK_VALUE
2407 The watch command now supports the mask argument which allows creation
2408 of masked watchpoints, if the current architecture supports this feature.
2410 info auto-load-scripts [REGEXP]
2411 This command was formerly named "maintenance print section-scripts".
2412 It is now generally useful and is no longer a maintenance-only command.
2414 info macro [-all] [--] MACRO
2415 The info macro command has new options `-all' and `--'. The first for
2416 printing all definitions of a macro. The second for explicitly specifying
2417 the end of arguments and the beginning of the macro name in case the macro
2418 name starts with a hyphen.
2420 collect[/s] EXPRESSIONS
2421 The tracepoint collect command now takes an optional modifier "/s"
2422 that directs it to dereference pointer-to-character types and
2423 collect the bytes of memory up to a zero byte. The behavior is
2424 similar to what you see when you use the regular print command on a
2425 string. An optional integer following the "/s" sets a bound on the
2426 number of bytes that will be collected.
2429 The trace start command now interprets any supplied arguments as a
2430 note to be recorded with the trace run, with an effect similar to
2431 setting the variable trace-notes.
2434 The trace stop command now interprets any arguments as a note to be
2435 mentioned along with the tstatus report that the trace was stopped
2436 with a command. The effect is similar to setting the variable
2439 * Tracepoints can now be enabled and disabled at any time after a trace
2440 experiment has been started using the standard "enable" and "disable"
2441 commands. It is now possible to start a trace experiment with no enabled
2442 tracepoints; GDB will display a warning, but will allow the experiment to
2443 begin, assuming that tracepoints will be enabled as needed while the trace
2446 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2447 locations with 4-byte instructions, when they were previously
2448 limited to locations with instructions of 5 bytes or longer.
2452 set debug dwarf2-read
2453 show debug dwarf2-read
2454 Turns on or off display of debugging messages related to reading
2455 DWARF debug info. The default is off.
2457 set debug symtab-create
2458 show debug symtab-create
2459 Turns on or off display of debugging messages related to symbol table
2460 creation. The default is off.
2463 show extended-prompt
2464 Set the GDB prompt, and allow escape sequences to be inserted to
2465 display miscellaneous information (see 'help set extended-prompt'
2466 for the list of sequences). This prompt (and any information
2467 accessed through the escape sequences) is updated every time the
2468 prompt is displayed.
2470 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2471 show print entry-values
2472 Set printing of frame argument values at function entry. In some cases
2473 GDB can determine the value of function argument which was passed by the
2474 function caller, even if the value was modified inside the called function.
2476 set debug entry-values
2477 show debug entry-values
2478 Control display of debugging info for determining frame argument values at
2479 function entry and virtual tail call frames.
2481 set basenames-may-differ
2482 show basenames-may-differ
2483 Set whether a source file may have multiple base names.
2484 (A "base name" is the name of a file with the directory part removed.
2485 Example: The base name of "/home/user/hello.c" is "hello.c".)
2486 If set, GDB will canonicalize file names (e.g., expand symlinks)
2487 before comparing them. Canonicalization is an expensive operation,
2488 but it allows the same file be known by more than one base name.
2489 If not set (the default), all source files are assumed to have just
2490 one base name, and gdb will do file name comparisons more efficiently.
2496 Set a user name and notes for the current and any future trace runs.
2497 This is useful for long-running and/or disconnected traces, to
2498 inform others (or yourself) as to who is running the trace, supply
2499 contact information, or otherwise explain what is going on.
2501 set trace-stop-notes
2502 show trace-stop-notes
2503 Set a note attached to the trace run, that is displayed when the
2504 trace has been stopped by a tstop command. This is useful for
2505 instance as an explanation, if you are stopping a trace run that was
2506 started by someone else.
2508 * New remote packets
2512 Dynamically enable a tracepoint in a started trace experiment.
2516 Dynamically disable a tracepoint in a started trace experiment.
2520 Set the user and notes of the trace run.
2524 Query the current status of a tracepoint.
2528 Query the minimum length of instruction at which a fast tracepoint may
2531 * Dcache size (number of lines) and line-size are now runtime-configurable
2532 via "set dcache line" and "set dcache line-size" commands.
2536 Texas Instruments TMS320C6x tic6x-*-*
2540 Renesas RL78 rl78-*-elf
2542 *** Changes in GDB 7.3.1
2544 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2546 *** Changes in GDB 7.3
2548 * GDB has a new command: "thread find [REGEXP]".
2549 It finds the thread id whose name, target id, or thread extra info
2550 matches the given regular expression.
2552 * The "catch syscall" command now works on mips*-linux* targets.
2554 * The -data-disassemble MI command now supports modes 2 and 3 for
2555 dumping the instruction opcodes.
2557 * New command line options
2559 -data-directory DIR Specify DIR as the "data-directory".
2560 This is mostly for testing purposes.
2562 * The "maint set python auto-load on|off" command has been renamed to
2563 "set auto-load-scripts on|off".
2565 * GDB has a new command: "set directories".
2566 It is like the "dir" command except that it replaces the
2567 source path list instead of augmenting it.
2569 * GDB now understands thread names.
2571 On GNU/Linux, "info threads" will display the thread name as set by
2572 prctl or pthread_setname_np.
2574 There is also a new command, "thread name", which can be used to
2575 assign a name internally for GDB to display.
2578 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2579 has been integrated into GDB.
2583 ** The function gdb.Write now accepts an optional keyword 'stream'.
2584 This keyword, when provided, will direct the output to either
2585 stdout, stderr, or GDB's logging output.
2587 ** Parameters can now be be sub-classed in Python, and in particular
2588 you may implement the get_set_doc and get_show_doc functions.
2589 This improves how Parameter set/show documentation is processed
2590 and allows for more dynamic content.
2592 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2593 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2594 have an is_valid method.
2596 ** Breakpoints can now be sub-classed in Python, and in particular
2597 you may implement a 'stop' function that is executed each time
2598 the inferior reaches that breakpoint.
2600 ** New function gdb.lookup_global_symbol looks up a global symbol.
2602 ** GDB values in Python are now callable if the value represents a
2603 function. For example, if 'some_value' represents a function that
2604 takes two integer parameters and returns a value, you can call
2605 that function like so:
2607 result = some_value (10,20)
2609 ** Module gdb.types has been added.
2610 It contains a collection of utilities for working with gdb.Types objects:
2611 get_basic_type, has_field, make_enum_dict.
2613 ** Module gdb.printing has been added.
2614 It contains utilities for writing and registering pretty-printers.
2615 New classes: PrettyPrinter, SubPrettyPrinter,
2616 RegexpCollectionPrettyPrinter.
2617 New function: register_pretty_printer.
2619 ** New commands "info pretty-printers", "enable pretty-printer" and
2620 "disable pretty-printer" have been added.
2622 ** gdb.parameter("directories") is now available.
2624 ** New function gdb.newest_frame returns the newest frame in the
2627 ** The gdb.InferiorThread class has a new "name" attribute. This
2628 holds the thread's name.
2630 ** Python Support for Inferior events.
2631 Python scripts can add observers to be notified of events
2632 occurring in the process being debugged.
2633 The following events are currently supported:
2634 - gdb.events.cont Continue event.
2635 - gdb.events.exited Inferior exited event.
2636 - gdb.events.stop Signal received, and Breakpoint hit events.
2640 ** GDB now puts template parameters in scope when debugging in an
2641 instantiation. For example, if you have:
2643 template<int X> int func (void) { return X; }
2645 then if you step into func<5>, "print X" will show "5". This
2646 feature requires proper debuginfo support from the compiler; it
2647 was added to GCC 4.5.
2649 ** The motion commands "next", "finish", "until", and "advance" now
2650 work better when exceptions are thrown. In particular, GDB will
2651 no longer lose control of the inferior; instead, the GDB will
2652 stop the inferior at the point at which the exception is caught.
2653 This functionality requires a change in the exception handling
2654 code that was introduced in GCC 4.5.
2656 * GDB now follows GCC's rules on accessing volatile objects when
2657 reading or writing target state during expression evaluation.
2658 One notable difference to prior behavior is that "print x = 0"
2659 no longer generates a read of x; the value of the assignment is
2660 now always taken directly from the value being assigned.
2662 * GDB now has some support for using labels in the program's source in
2663 linespecs. For instance, you can use "advance label" to continue
2664 execution to a label.
2666 * GDB now has support for reading and writing a new .gdb_index
2667 section. This section holds a fast index of DWARF debugging
2668 information and can be used to greatly speed up GDB startup and
2669 operation. See the documentation for `save gdb-index' for details.
2671 * The "watch" command now accepts an optional "-location" argument.
2672 When used, this causes GDB to watch the memory referred to by the
2673 expression. Such a watchpoint is never deleted due to it going out
2676 * GDB now supports thread debugging of core dumps on GNU/Linux.
2678 GDB now activates thread debugging using the libthread_db library
2679 when debugging GNU/Linux core dumps, similarly to when debugging
2680 live processes. As a result, when debugging a core dump file, GDB
2681 is now able to display pthread_t ids of threads. For example, "info
2682 threads" shows the same output as when debugging the process when it
2683 was live. In earlier releases, you'd see something like this:
2686 * 1 LWP 6780 main () at main.c:10
2688 While now you see this:
2691 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2693 It is also now possible to inspect TLS variables when debugging core
2696 When debugging a core dump generated on a machine other than the one
2697 used to run GDB, you may need to point GDB at the correct
2698 libthread_db library with the "set libthread-db-search-path"
2699 command. See the user manual for more details on this command.
2701 * When natively debugging programs on PowerPC BookE processors running
2702 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2703 which stop execution of the inferior whenever it executes an instruction
2704 at any address within the specified range. See the "PowerPC Embedded"
2705 section in the user manual for more details.
2707 * New features in the GDB remote stub, GDBserver
2709 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2710 and i686 LynxOS (version 5.x).
2712 ** GDBserver is now supported on Blackfin Linux.
2714 * New native configurations
2716 ia64 HP-UX ia64-*-hpux*
2720 Analog Devices, Inc. Blackfin Processor bfin-*
2722 * Ada task switching is now supported on sparc-elf targets when
2723 debugging a program using the Ravenscar Profile. For more information,
2724 see the "Tasking Support when using the Ravenscar Profile" section
2725 in the GDB user manual.
2727 * Guile support was removed.
2729 * New features in the GNU simulator
2731 ** The --map-info flag lists all known core mappings.
2733 ** CFI flashes may be simulated via the "cfi" device.
2735 *** Changes in GDB 7.2
2737 * Shared library support for remote targets by default
2739 When GDB is configured for a generic, non-OS specific target, like
2740 for example, --target=arm-eabi or one of the many *-*-elf targets,
2741 GDB now queries remote stubs for loaded shared libraries using the
2742 `qXfer:libraries:read' packet. Previously, shared library support
2743 was always disabled for such configurations.
2747 ** Argument Dependent Lookup (ADL)
2749 In C++ ADL lookup directs function search to the namespaces of its
2750 arguments even if the namespace has not been imported.
2760 Here the compiler will search for `foo' in the namespace of 'b'
2761 and find A::foo. GDB now supports this. This construct is commonly
2762 used in the Standard Template Library for operators.
2764 ** Improved User Defined Operator Support
2766 In addition to member operators, GDB now supports lookup of operators
2767 defined in a namespace and imported with a `using' directive, operators
2768 defined in the global scope, operators imported implicitly from an
2769 anonymous namespace, and the ADL operators mentioned in the previous
2771 GDB now also supports proper overload resolution for all the previously
2772 mentioned flavors of operators.
2774 ** static const class members
2776 Printing of static const class members that are initialized in the
2777 class definition has been fixed.
2779 * Windows Thread Information Block access.
2781 On Windows targets, GDB now supports displaying the Windows Thread
2782 Information Block (TIB) structure. This structure is visible either
2783 by using the new command `info w32 thread-information-block' or, by
2784 dereferencing the new convenience variable named `$_tlb', a
2785 thread-specific pointer to the TIB. This feature is also supported
2786 when remote debugging using GDBserver.
2788 * Static tracepoints
2790 Static tracepoints are calls in the user program into a tracing
2791 library. One such library is a port of the LTTng kernel tracer to
2792 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2793 When debugging with GDBserver, GDB now supports combining the GDB
2794 tracepoint machinery with such libraries. For example: the user can
2795 use GDB to probe a static tracepoint marker (a call from the user
2796 program into the tracing library) with the new "strace" command (see
2797 "New commands" below). This creates a "static tracepoint" in the
2798 breakpoint list, that can be manipulated with the same feature set
2799 as fast and regular tracepoints. E.g., collect registers, local and
2800 global variables, collect trace state variables, and define
2801 tracepoint conditions. In addition, the user can collect extra
2802 static tracepoint marker specific data, by collecting the new
2803 $_sdata internal variable. When analyzing the trace buffer, you can
2804 inspect $_sdata like any other variable available to GDB. For more
2805 information, see the "Tracepoints" chapter in GDB user manual. New
2806 remote packets have been defined to support static tracepoints, see
2807 the "New remote packets" section below.
2809 * Better reconstruction of tracepoints after disconnected tracing
2811 GDB will attempt to download the original source form of tracepoint
2812 definitions when starting a trace run, and then will upload these
2813 upon reconnection to the target, resulting in a more accurate
2814 reconstruction of the tracepoints that are in use on the target.
2818 You can now exercise direct control over the ways that GDB can
2819 affect your program. For instance, you can disallow the setting of
2820 breakpoints, so that the program can run continuously (assuming
2821 non-stop mode). In addition, the "observer" variable is available
2822 to switch all of the different controls; in observer mode, GDB
2823 cannot affect the target's behavior at all, which is useful for
2824 tasks like diagnosing live systems in the field.
2826 * The new convenience variable $_thread holds the number of the
2829 * New remote packets
2833 Return the address of the Windows Thread Information Block of a given thread.
2837 In response to several of the tracepoint packets, the target may now
2838 also respond with a number of intermediate `qRelocInsn' request
2839 packets before the final result packet, to have GDB handle
2840 relocating an instruction to execute at a different address. This
2841 is particularly useful for stubs that support fast tracepoints. GDB
2842 reports support for this feature in the qSupported packet.
2846 List static tracepoint markers in the target program.
2850 List static tracepoint markers at a given address in the target
2853 qXfer:statictrace:read
2855 Read the static trace data collected (by a `collect $_sdata'
2856 tracepoint action). The remote stub reports support for this packet
2857 to gdb's qSupported query.
2861 Send the current settings of GDB's permission flags.
2865 Send part of the source (textual) form of a tracepoint definition,
2866 which includes location, conditional, and action list.
2868 * The source command now accepts a -s option to force searching for the
2869 script in the source search path even if the script name specifies
2872 * New features in the GDB remote stub, GDBserver
2874 - GDBserver now support tracepoints (including fast tracepoints, and
2875 static tracepoints). The feature is currently supported by the
2876 i386-linux and amd64-linux builds. See the "Tracepoints support
2877 in gdbserver" section in the manual for more information.
2879 GDBserver JIT compiles the tracepoint's conditional agent
2880 expression bytecode into native code whenever possible for low
2881 overhead dynamic tracepoints conditionals. For such tracepoints,
2882 an expression that examines program state is evaluated when the
2883 tracepoint is reached, in order to determine whether to capture
2884 trace data. If the condition is simple and false, processing the
2885 tracepoint finishes very quickly and no data is gathered.
2887 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2888 for static tracepoints support.
2890 - GDBserver now supports x86_64 Windows 64-bit debugging.
2892 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2893 it understands register description.
2895 * The --batch flag now disables pagination and queries.
2897 * X86 general purpose registers
2899 GDB now supports reading/writing byte, word and double-word x86
2900 general purpose registers directly. This means you can use, say,
2901 $ah or $ax to refer, respectively, to the byte register AH and
2902 16-bit word register AX that are actually portions of the 32-bit
2903 register EAX or 64-bit register RAX.
2905 * The `commands' command now accepts a range of breakpoints to modify.
2906 A plain `commands' following a command that creates multiple
2907 breakpoints affects all the breakpoints set by that command. This
2908 applies to breakpoints set by `rbreak', and also applies when a
2909 single `break' command creates multiple breakpoints (e.g.,
2910 breakpoints on overloaded c++ functions).
2912 * The `rbreak' command now accepts a filename specification as part of
2913 its argument, limiting the functions selected by the regex to those
2914 in the specified file.
2916 * Support for remote debugging Windows and SymbianOS shared libraries
2917 from Unix hosts has been improved. Non Windows GDB builds now can
2918 understand target reported file names that follow MS-DOS based file
2919 system semantics, such as file names that include drive letters and
2920 use the backslash character as directory separator. This makes it
2921 possible to transparently use the "set sysroot" and "set
2922 solib-search-path" on Unix hosts to point as host copies of the
2923 target's shared libraries. See the new command "set
2924 target-file-system-kind" described below, and the "Commands to
2925 specify files" section in the user manual for more information.
2929 eval template, expressions...
2930 Convert the values of one or more expressions under the control
2931 of the string template to a command line, and call it.
2933 set target-file-system-kind unix|dos-based|auto
2934 show target-file-system-kind
2935 Set or show the assumed file system kind for target reported file
2938 save breakpoints <filename>
2939 Save all current breakpoint definitions to a file suitable for use
2940 in a later debugging session. To read the saved breakpoint
2941 definitions, use the `source' command.
2943 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2946 info static-tracepoint-markers
2947 Display information about static tracepoint markers in the target.
2949 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2950 Define a static tracepoint by probing a marker at the given
2951 function, line, address, or marker ID.
2955 Enable and disable observer mode.
2957 set may-write-registers on|off
2958 set may-write-memory on|off
2959 set may-insert-breakpoints on|off
2960 set may-insert-tracepoints on|off
2961 set may-insert-fast-tracepoints on|off
2962 set may-interrupt on|off
2963 Set individual permissions for GDB effects on the target. Note that
2964 some of these settings can have undesirable or surprising
2965 consequences, particularly when changed in the middle of a session.
2966 For instance, disabling the writing of memory can prevent
2967 breakpoints from being inserted, cause single-stepping to fail, or
2968 even crash your program, if you disable after breakpoints have been
2969 inserted. However, GDB should not crash.
2971 set record memory-query on|off
2972 show record memory-query
2973 Control whether to stop the inferior if memory changes caused
2974 by an instruction cannot be recorded.
2979 The disassemble command now supports "start,+length" form of two arguments.
2983 ** GDB now provides a new directory location, called the python directory,
2984 where Python scripts written for GDB can be installed. The location
2985 of that directory is <data-directory>/python, where <data-directory>
2986 is the GDB data directory. For more details, see section `Scripting
2987 GDB using Python' in the manual.
2989 ** The GDB Python API now has access to breakpoints, symbols, symbol
2990 tables, program spaces, inferiors, threads and frame's code blocks.
2991 Additionally, GDB Parameters can now be created from the API, and
2992 manipulated via set/show in the CLI.
2994 ** New functions gdb.target_charset, gdb.target_wide_charset,
2995 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2997 ** New exception gdb.GdbError.
2999 ** Pretty-printers are now also looked up in the current program space.
3001 ** Pretty-printers can now be individually enabled and disabled.
3003 ** GDB now looks for names of Python scripts to auto-load in a
3004 special section named `.debug_gdb_scripts', in addition to looking
3005 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3007 * Tracepoint actions were unified with breakpoint commands. In particular,
3008 there are no longer differences in "info break" output for breakpoints and
3009 tracepoints and the "commands" command can be used for both tracepoints and
3010 regular breakpoints.
3014 ARM Symbian arm*-*-symbianelf*
3016 * D language support.
3017 GDB now supports debugging programs written in the D programming
3020 * GDB now supports the extended ptrace interface for PowerPC which is
3021 available since Linux kernel version 2.6.34. This automatically enables
3022 any hardware breakpoints and additional hardware watchpoints available in
3023 the processor. The old ptrace interface exposes just one hardware
3024 watchpoint and no hardware breakpoints.
3026 * GDB is now able to use the Data Value Compare (DVC) register available on
3027 embedded PowerPC processors to implement in hardware simple watchpoint
3028 conditions of the form:
3030 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3032 This works in native GDB running on Linux kernels with the extended ptrace
3033 interface mentioned above.
3035 *** Changes in GDB 7.1
3039 ** Namespace Support
3041 GDB now supports importing of namespaces in C++. This enables the
3042 user to inspect variables from imported namespaces. Support for
3043 namepace aliasing has also been added. So, if a namespace is
3044 aliased in the current scope (e.g. namepace C=A; ) the user can
3045 print variables using the alias (e.g. (gdb) print C::x).
3049 All known bugs relating to the printing of virtual base class were
3050 fixed. It is now possible to call overloaded static methods using a
3055 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3056 and reinterpret_cast<> are now handled by the C++ expression parser.
3060 Xilinx MicroBlaze microblaze-*-*
3065 Xilinx MicroBlaze microblaze
3068 * Multi-program debugging.
3070 GDB now has support for multi-program (a.k.a. multi-executable or
3071 multi-exec) debugging. This allows for debugging multiple inferiors
3072 simultaneously each running a different program under the same GDB
3073 session. See "Debugging Multiple Inferiors and Programs" in the
3074 manual for more information. This implied some user visible changes
3075 in the multi-inferior support. For example, "info inferiors" now
3076 lists inferiors that are not running yet or that have exited
3077 already. See also "New commands" and "New options" below.
3079 * New tracing features
3081 GDB's tracepoint facility now includes several new features:
3083 ** Trace state variables
3085 GDB tracepoints now include support for trace state variables, which
3086 are variables managed by the target agent during a tracing
3087 experiment. They are useful for tracepoints that trigger each
3088 other, so for instance one tracepoint can count hits in a variable,
3089 and then a second tracepoint has a condition that is true when the
3090 count reaches a particular value. Trace state variables share the
3091 $-syntax of GDB convenience variables, and can appear in both
3092 tracepoint actions and condition expressions. Use the "tvariable"
3093 command to create, and "info tvariables" to view; see "Trace State
3094 Variables" in the manual for more detail.
3098 GDB now includes an option for defining fast tracepoints, which
3099 targets may implement more efficiently, such as by installing a jump
3100 into the target agent rather than a trap instruction. The resulting
3101 speedup can be by two orders of magnitude or more, although the
3102 tradeoff is that some program locations on some target architectures
3103 might not allow fast tracepoint installation, for instance if the
3104 instruction to be replaced is shorter than the jump. To request a
3105 fast tracepoint, use the "ftrace" command, with syntax identical to
3106 the regular trace command.
3108 ** Disconnected tracing
3110 It is now possible to detach GDB from the target while it is running
3111 a trace experiment, then reconnect later to see how the experiment
3112 is going. In addition, a new variable disconnected-tracing lets you
3113 tell the target agent whether to continue running a trace if the
3114 connection is lost unexpectedly.
3118 GDB now has the ability to save the trace buffer into a file, and
3119 then use that file as a target, similarly to you can do with
3120 corefiles. You can select trace frames, print data that was
3121 collected in them, and use tstatus to display the state of the
3122 tracing run at the moment that it was saved. To create a trace
3123 file, use "tsave <filename>", and to use it, do "target tfile
3126 ** Circular trace buffer
3128 You can ask the target agent to handle the trace buffer as a
3129 circular buffer, discarding the oldest trace frames to make room for
3130 newer ones, by setting circular-trace-buffer to on. This feature may
3131 not be available for all target agents.
3136 The disassemble command, when invoked with two arguments, now requires
3137 the arguments to be comma-separated.
3140 The info variables command now displays variable definitions. Files
3141 which only declare a variable are not shown.
3144 The source command is now capable of sourcing Python scripts.
3145 This feature is dependent on the debugger being build with Python
3148 Related to this enhancement is also the introduction of a new command
3149 "set script-extension" (see below).
3151 * New commands (for set/show, see "New options" below)
3153 record save [<FILENAME>]
3154 Save a file (in core file format) containing the process record
3155 execution log for replay debugging at a later time.
3157 record restore <FILENAME>
3158 Restore the process record execution log that was saved at an
3159 earlier time, for replay debugging.
3161 add-inferior [-copies <N>] [-exec <FILENAME>]
3164 clone-inferior [-copies <N>] [ID]
3165 Make a new inferior ready to execute the same program another
3166 inferior has loaded.
3171 maint info program-spaces
3172 List the program spaces loaded into GDB.
3174 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3175 show remote interrupt-sequence
3176 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3177 as the sequence to the remote target in order to interrupt the execution.
3178 Ctrl-C is a default. Some system prefers BREAK which is high level of
3179 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3180 Magic SysRq g. It is BREAK signal and character 'g'.
3182 set remote interrupt-on-connect [on | off]
3183 show remote interrupt-on-connect
3184 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3185 remote target when gdb connects to it. This is needed when you debug
3188 set remotebreak [on | off]
3190 Deprecated. Use "set/show remote interrupt-sequence" instead.
3192 tvariable $NAME [ = EXP ]
3193 Create or modify a trace state variable.
3196 List trace state variables and their values.
3198 delete tvariable $NAME ...
3199 Delete one or more trace state variables.
3202 Evaluate the given expressions without collecting anything into the
3203 trace buffer. (Valid in tracepoint actions only.)
3205 ftrace FN / FILE:LINE / *ADDR
3206 Define a fast tracepoint at the given function, line, or address.
3208 * New expression syntax
3210 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3211 GDB now parses 0b101010 identically with 42.
3215 set follow-exec-mode new|same
3216 show follow-exec-mode
3217 Control whether GDB reuses the same inferior across an exec call or
3218 creates a new one. This is useful to be able to restart the old
3219 executable after the inferior having done an exec call.
3221 set default-collect EXPR, ...
3222 show default-collect
3223 Define a list of expressions to be collected at each tracepoint.
3224 This is a useful way to ensure essential items are not overlooked,
3225 such as registers or a critical global variable.
3227 set disconnected-tracing
3228 show disconnected-tracing
3229 If set to 1, the target is instructed to continue tracing if it
3230 loses its connection to GDB. If 0, the target is to stop tracing
3233 set circular-trace-buffer
3234 show circular-trace-buffer
3235 If set to on, the target is instructed to use a circular trace buffer
3236 and discard the oldest trace frames instead of stopping the trace due
3237 to a full trace buffer. If set to off, the trace stops when the buffer
3238 fills up. Some targets may not support this.
3240 set script-extension off|soft|strict
3241 show script-extension
3242 If set to "off", the debugger does not perform any script language
3243 recognition, and all sourced files are assumed to be GDB scripts.
3244 If set to "soft" (the default), files are sourced according to
3245 filename extension, falling back to GDB scripts if the first
3247 If set to "strict", files are sourced according to filename extension.
3249 set ada trust-PAD-over-XVS on|off
3250 show ada trust-PAD-over-XVS
3251 If off, activate a workaround against a bug in the debugging information
3252 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3253 the GCC sources for more information about the GNAT encoding and
3254 PAD types in particular). It is always safe to set this option to
3255 off, but this introduces a slight performance penalty. The default
3258 * Python API Improvements
3260 ** GDB provides the new class gdb.LazyString. This is useful in
3261 some pretty-printing cases. The new method gdb.Value.lazy_string
3262 provides a simple way to create objects of this type.
3264 ** The fields returned by gdb.Type.fields now have an
3265 `is_base_class' attribute.
3267 ** The new method gdb.Type.range returns the range of an array type.
3269 ** The new method gdb.parse_and_eval can be used to parse and
3270 evaluate an expression.
3272 * New remote packets
3275 Define a trace state variable.
3278 Get the current value of a trace state variable.
3281 Set desired tracing behavior upon disconnection.
3284 Set the trace buffer to be linear or circular.
3287 Get data about the tracepoints currently in use.
3291 Process record now works correctly with hardware watchpoints.
3293 Multiple bug fixes have been made to the mips-irix port, making it
3294 much more reliable. In particular:
3295 - Debugging threaded applications is now possible again. Previously,
3296 GDB would hang while starting the program, or while waiting for
3297 the program to stop at a breakpoint.
3298 - Attaching to a running process no longer hangs.
3299 - An error occurring while loading a core file has been fixed.
3300 - Changing the value of the PC register now works again. This fixes
3301 problems observed when using the "jump" command, or when calling
3302 a function from GDB, or even when assigning a new value to $pc.
3303 - With the "finish" and "return" commands, the return value for functions
3304 returning a small array is now correctly printed.
3305 - It is now possible to break on shared library code which gets executed
3306 during a shared library init phase (code executed while executing
3307 their .init section). Previously, the breakpoint would have no effect.
3308 - GDB is now able to backtrace through the signal handler for
3309 non-threaded programs.
3311 PIE (Position Independent Executable) programs debugging is now supported.
3312 This includes debugging execution of PIC (Position Independent Code) shared
3313 libraries although for that, it should be possible to run such libraries as an
3316 *** Changes in GDB 7.0
3318 * GDB now has an interface for JIT compilation. Applications that
3319 dynamically generate code can create symbol files in memory and register
3320 them with GDB. For users, the feature should work transparently, and
3321 for JIT developers, the interface is documented in the GDB manual in the
3322 "JIT Compilation Interface" chapter.
3324 * Tracepoints may now be conditional. The syntax is as for
3325 breakpoints; either an "if" clause appended to the "trace" command,
3326 or the "condition" command is available. GDB sends the condition to
3327 the target for evaluation using the same bytecode format as is used
3328 for tracepoint actions.
3330 * The disassemble command now supports: an optional /r modifier, print the
3331 raw instructions in hex as well as in symbolic form, and an optional /m
3332 modifier to print mixed source+assembly.
3334 * Process record and replay
3336 In a architecture environment that supports ``process record and
3337 replay'', ``process record and replay'' target can record a log of
3338 the process execution, and replay it with both forward and reverse
3341 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3342 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3343 set execution-direction {forward|reverse}, for targets that support
3346 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3347 feature is available with a native GDB running on kernel version
3350 * GDB now has support for multi-byte and wide character sets on the
3351 target. Strings whose character type is wchar_t, char16_t, or
3352 char32_t are now correctly printed. GDB supports wide- and unicode-
3353 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3354 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3355 `printf'. This feature requires iconv to work properly; if your
3356 system does not have a working iconv, GDB can use GNU libiconv. See
3357 the installation instructions for more information.
3359 * GDB now supports automatic retrieval of shared library files from
3360 remote targets. To use this feature, specify a system root that begins
3361 with the `remote:' prefix, either via the `set sysroot' command or via
3362 the `--with-sysroot' configure-time option.
3364 * "info sharedlibrary" now takes an optional regex of libraries to show,
3365 and it now reports if a shared library has no debugging information.
3367 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3368 now complete on file names.
3370 * When completing in expressions, gdb will attempt to limit
3371 completions to allowable structure or union fields, where appropriate.
3372 For instance, consider:
3374 # struct example { int f1; double f2; };
3375 # struct example variable;
3378 If the user types TAB at the end of this command line, the available
3379 completions will be "f1" and "f2".
3381 * Inlined functions are now supported. They show up in backtraces, and
3382 the "step", "next", and "finish" commands handle them automatically.
3384 * GDB now supports the token-splicing (##) and stringification (#)
3385 operators when expanding macros. It also supports variable-arity
3388 * GDB now supports inspecting extra signal information, exported by
3389 the new $_siginfo convenience variable. The feature is currently
3390 implemented on linux ARM, i386 and amd64.
3392 * GDB can now display the VFP floating point registers and NEON vector
3393 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3394 can provide these registers (requires Linux 2.6.30 or later). Remote
3395 and simulator targets may also provide them.
3397 * New remote packets
3400 Search memory for a sequence of bytes.
3403 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3404 operation over reliable transport links. Use of this packet is
3405 controlled by the `set remote noack-packet' command.
3408 Kill the process with the specified process ID. Use this in preference
3409 to `k' when multiprocess protocol extensions are supported.
3412 Obtains additional operating system information
3416 Read or write additional signal information.
3418 * Removed remote protocol undocumented extension
3420 An undocumented extension to the remote protocol's `S' stop reply
3421 packet that permited the stub to pass a process id was removed.
3422 Remote servers should use the `T' stop reply packet instead.
3424 * GDB now supports multiple function calling conventions according to the
3425 DWARF-2 DW_AT_calling_convention function attribute.
3427 * The SH target utilizes the aforementioned change to distinguish between gcc
3428 and Renesas calling convention. It also adds the new CLI commands
3429 `set/show sh calling-convention'.
3431 * GDB can now read compressed debug sections, as produced by GNU gold
3432 with the --compress-debug-sections=zlib flag.
3434 * 64-bit core files are now supported on AIX.
3436 * Thread switching is now supported on Tru64.
3438 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3439 which will be allocated using malloc later in program execution.
3441 * The qXfer:libraries:read remote procotol packet now allows passing a
3442 list of section offsets.
3444 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3445 conditions handling signals delivered during attach or thread creation
3446 have also been fixed.
3448 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3449 From the user's standpoint, all unqualified instances of True and False
3450 are treated as the standard definitions, regardless of context.
3452 * GDB now parses C++ symbol and type names more flexibly. For
3455 template<typename T> class C { };
3458 GDB will now correctly handle all of:
3460 ptype C<char const *>
3461 ptype C<char const*>
3462 ptype C<const char *>
3463 ptype C<const char*>
3465 * New features in the GDB remote stub, gdbserver
3467 - The "--wrapper" command-line argument tells gdbserver to use a
3468 wrapper program to launch programs for debugging.
3470 - On PowerPC and S/390 targets, it is now possible to use a single
3471 gdbserver executable to debug both 32-bit and 64-bit programs.
3472 (This requires gdbserver itself to be built as a 64-bit executable.)
3474 - gdbserver uses the new noack protocol mode for TCP connections to
3475 reduce communications latency, if also supported and enabled in GDB.
3477 - Support for the sparc64-linux-gnu target is now included in
3480 - The amd64-linux build of gdbserver now supports debugging both
3481 32-bit and 64-bit programs.
3483 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3484 now support hardware watchpoints, and will use them automatically
3489 GDB now has support for scripting using Python. Whether this is
3490 available is determined at configure time.
3492 New GDB commands can now be written in Python.
3494 * Ada tasking support
3496 Ada tasks can now be inspected in GDB. The following commands have
3500 Print the list of Ada tasks.
3502 Print detailed information about task number N.
3504 Print the task number of the current task.
3506 Switch the context of debugging to task number N.
3508 * Support for user-defined prefixed commands. The "define" command can
3509 add new commands to existing prefixes, e.g. "target".
3511 * Multi-inferior, multi-process debugging.
3513 GDB now has generalized support for multi-inferior debugging. See
3514 "Debugging Multiple Inferiors" in the manual for more information.
3515 Although availability still depends on target support, the command
3516 set is more uniform now. The GNU/Linux specific multi-forks support
3517 has been migrated to this new framework. This implied some user
3518 visible changes; see "New commands" and also "Removed commands"
3521 * Target descriptions can now describe the target OS ABI. See the
3522 "Target Description Format" section in the user manual for more
3525 * Target descriptions can now describe "compatible" architectures
3526 to indicate that the target can execute applications for a different
3527 architecture in addition to those for the main target architecture.
3528 See the "Target Description Format" section in the user manual for
3531 * Multi-architecture debugging.
3533 GDB now includes general supports for debugging applications on
3534 hybrid systems that use more than one single processor architecture
3535 at the same time. Each such hybrid architecture still requires
3536 specific support to be added. The only hybrid architecture supported
3537 in this version of GDB is the Cell Broadband Engine.
3539 * GDB now supports integrated debugging of Cell/B.E. applications that
3540 use both the PPU and SPU architectures. To enable support for hybrid
3541 Cell/B.E. debugging, you need to configure GDB to support both the
3542 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3543 --enable-targets configure option.
3545 * Non-stop mode debugging.
3547 For some targets, GDB now supports an optional mode of operation in
3548 which you can examine stopped threads while other threads continue
3549 to execute freely. This is referred to as non-stop mode, with the
3550 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3551 section in the user manual for more information.
3553 To be able to support remote non-stop debugging, a remote stub needs
3554 to implement the non-stop mode remote protocol extensions, as
3555 described in the "Remote Non-Stop" section of the user manual. The
3556 GDB remote stub, gdbserver, has been adjusted to support these
3557 extensions on linux targets.
3559 * New commands (for set/show, see "New options" below)
3561 catch syscall [NAME(S) | NUMBER(S)]
3562 Catch system calls. Arguments, which should be names of system
3563 calls or their numbers, mean catch only those syscalls. Without
3564 arguments, every syscall will be caught. When the inferior issues
3565 any of the specified syscalls, GDB will stop and announce the system
3566 call, both when it is called and when its call returns. This
3567 feature is currently available with a native GDB running on the
3568 Linux Kernel, under the following architectures: x86, x86_64,
3569 PowerPC and PowerPC64.
3571 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3573 Search memory for a sequence of bytes.
3575 maint set python print-stack
3576 maint show python print-stack
3577 Show a stack trace when an error is encountered in a Python script.
3580 Invoke CODE by passing it to the Python interpreter.
3585 These allow macros to be defined, undefined, and listed
3589 Show operating system information about processes.
3592 List the inferiors currently under GDB's control.
3595 Switch focus to inferior number NUM.
3598 Detach from inferior number NUM.
3601 Kill inferior number NUM.
3605 set spu stop-on-load
3606 show spu stop-on-load
3607 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3609 set spu auto-flush-cache
3610 show spu auto-flush-cache
3611 Control whether to automatically flush the software-managed cache
3612 during Cell/B.E. debugging.
3614 set sh calling-convention
3615 show sh calling-convention
3616 Control the calling convention used when calling SH target functions.
3619 show debug timestamp
3620 Control display of timestamps with GDB debugging output.
3622 set disassemble-next-line
3623 show disassemble-next-line
3624 Control display of disassembled source lines or instructions when
3627 set remote noack-packet
3628 show remote noack-packet
3629 Set/show the use of remote protocol QStartNoAckMode packet. See above
3630 under "New remote packets."
3632 set remote query-attached-packet
3633 show remote query-attached-packet
3634 Control use of remote protocol `qAttached' (query-attached) packet.
3636 set remote read-siginfo-object
3637 show remote read-siginfo-object
3638 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3641 set remote write-siginfo-object
3642 show remote write-siginfo-object
3643 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3646 set remote reverse-continue
3647 show remote reverse-continue
3648 Control use of remote protocol 'bc' (reverse-continue) packet.
3650 set remote reverse-step
3651 show remote reverse-step
3652 Control use of remote protocol 'bs' (reverse-step) packet.
3654 set displaced-stepping
3655 show displaced-stepping
3656 Control displaced stepping mode. Displaced stepping is a way to
3657 single-step over breakpoints without removing them from the debuggee.
3658 Also known as "out-of-line single-stepping".
3661 show debug displaced
3662 Control display of debugging info for displaced stepping.
3664 maint set internal-error
3665 maint show internal-error
3666 Control what GDB does when an internal error is detected.
3668 maint set internal-warning
3669 maint show internal-warning
3670 Control what GDB does when an internal warning is detected.
3675 Use a wrapper program to launch programs for debugging.
3677 set multiple-symbols (all|ask|cancel)
3678 show multiple-symbols
3679 The value of this variable can be changed to adjust the debugger behavior
3680 when an expression or a breakpoint location contains an ambiguous symbol
3681 name (an overloaded function name, for instance).
3683 set breakpoint always-inserted
3684 show breakpoint always-inserted
3685 Keep breakpoints always inserted in the target, as opposed to inserting
3686 them when resuming the target, and removing them when the target stops.
3687 This option can improve debugger performance on slow remote targets.
3689 set arm fallback-mode (arm|thumb|auto)
3690 show arm fallback-mode
3691 set arm force-mode (arm|thumb|auto)
3693 These commands control how ARM GDB determines whether instructions
3694 are ARM or Thumb. The default for both settings is auto, which uses
3695 the current CPSR value for instructions without symbols; previous
3696 versions of GDB behaved as if "set arm fallback-mode arm".
3698 set disable-randomization
3699 show disable-randomization
3700 Standalone programs run with the virtual address space randomization enabled
3701 by default on some platforms. This option keeps the addresses stable across
3702 multiple debugging sessions.
3706 Control whether other threads are stopped or not when some thread hits
3711 Requests that asynchronous execution is enabled in the target, if available.
3712 In this case, it's possible to resume target in the background, and interact
3713 with GDB while the target is running. "show target-async" displays the
3714 current state of asynchronous execution of the target.
3716 set target-wide-charset
3717 show target-wide-charset
3718 The target-wide-charset is the name of the character set that GDB
3719 uses when printing characters whose type is wchar_t.
3721 set tcp auto-retry (on|off)
3723 set tcp connect-timeout
3724 show tcp connect-timeout
3725 These commands allow GDB to retry failed TCP connections to a remote stub
3726 with a specified timeout period; this is useful if the stub is launched
3727 in parallel with GDB but may not be ready to accept connections immediately.
3729 set libthread-db-search-path
3730 show libthread-db-search-path
3731 Control list of directories which GDB will search for appropriate
3734 set schedule-multiple (on|off)
3735 show schedule-multiple
3736 Allow GDB to resume all threads of all processes or only threads of
3737 the current process.
3741 Use more aggressive caching for accesses to the stack. This improves
3742 performance of remote debugging (particularly backtraces) without
3743 affecting correctness.
3745 set interactive-mode (on|off|auto)
3746 show interactive-mode
3747 Control whether GDB runs in interactive mode (on) or not (off).
3748 When in interactive mode, GDB waits for the user to answer all
3749 queries. Otherwise, GDB does not wait and assumes the default
3750 answer. When set to auto (the default), GDB determines which
3751 mode to use based on the stdin settings.
3756 For program forks, this is replaced by the new more generic `info
3757 inferiors' command. To list checkpoints, you can still use the
3758 `info checkpoints' command, which was an alias for the `info forks'
3762 Replaced by the new `inferior' command. To switch between
3763 checkpoints, you can still use the `restart' command, which was an
3764 alias for the `fork' command.
3767 This is removed, since some targets don't have a notion of
3768 processes. To switch between processes, you can still use the
3769 `inferior' command using GDB's own inferior number.
3772 For program forks, this is replaced by the new more generic `kill
3773 inferior' command. To delete a checkpoint, you can still use the
3774 `delete checkpoint' command, which was an alias for the `delete
3778 For program forks, this is replaced by the new more generic `detach
3779 inferior' command. To detach a checkpoint, you can still use the
3780 `detach checkpoint' command, which was an alias for the `detach
3783 * New native configurations
3785 x86/x86_64 Darwin i[34567]86-*-darwin*
3787 x86_64 MinGW x86_64-*-mingw*
3791 Lattice Mico32 lm32-*
3792 x86 DICOS i[34567]86-*-dicos*
3793 x86_64 DICOS x86_64-*-dicos*
3796 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3797 (mingw32ce) debugging.
3803 These commands were actually not implemented on any target.
3805 *** Changes in GDB 6.8
3807 * New native configurations
3809 NetBSD/hppa hppa*-*netbsd*
3810 Xtensa GNU/Linux xtensa*-*-linux*
3814 NetBSD/hppa hppa*-*-netbsd*
3815 Xtensa GNU/Lunux xtensa*-*-linux*
3817 * Change in command line behavior -- corefiles vs. process ids.
3819 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3820 attaching to process NUMBER fails, GDB no longer attempts to open a
3821 core file named NUMBER. Attaching to a program using the -c option
3822 is no longer supported. Instead, use the '-p' or '--pid' options.
3824 * GDB can now be built as a native debugger for debugging Windows x86
3825 (mingw32) Portable Executable (PE) programs.
3827 * Pending breakpoints no longer change their number when their address
3830 * GDB now supports breakpoints with multiple locations,
3831 including breakpoints on C++ constructors, inside C++ templates,
3832 and in inlined functions.
3834 * GDB's ability to debug optimized code has been improved. GDB more
3835 accurately identifies function bodies and lexical blocks that occupy
3836 more than one contiguous range of addresses.
3838 * Target descriptions can now describe registers for PowerPC.
3840 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3841 registers on PowerPC targets.
3843 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3844 targets even when the libthread_db library is not available.
3846 * The GDB remote stub, gdbserver, now supports the new file transfer
3847 commands (remote put, remote get, and remote delete).
3849 * The GDB remote stub, gdbserver, now supports run and attach in
3850 extended-remote mode.
3852 * hppa*64*-*-hpux11* target broken
3853 The debugger is unable to start a program and fails with the following
3854 error: "Error trying to get information about dynamic linker".
3855 The gdb-6.7 release is also affected.
3857 * GDB now supports the --enable-targets= configure option to allow
3858 building a single GDB executable that supports multiple remote
3859 target architectures.
3861 * GDB now supports debugging C and C++ programs which use the
3862 Decimal Floating Point extension. In addition, the PowerPC target
3863 now has a set of pseudo-registers to inspect decimal float values
3864 stored in two consecutive float registers.
3866 * The -break-insert MI command can optionally create pending
3869 * Improved support for debugging Ada
3870 Many improvements to the Ada language support have been made. These
3872 - Better support for Ada2005 interface types
3873 - Improved handling of arrays and slices in general
3874 - Better support for Taft-amendment types
3875 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3877 - Improved command completion in Ada
3880 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3885 set print frame-arguments (all|scalars|none)
3886 show print frame-arguments
3887 The value of this variable can be changed to control which argument
3888 values should be printed by the debugger when displaying a frame.
3893 Transfer files to and from a remote target, and delete remote files.
3900 Transfer files to and from a remote target, and delete remote files.
3902 * New remote packets
3909 Open, close, read, write, and delete files on the remote system.
3912 Attach to an existing process on the remote system, in extended-remote
3916 Run a new process on the remote system, in extended-remote mode.
3918 *** Changes in GDB 6.7
3920 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3921 bfd, libiberty and opcodes, as revealed by static analysis donated by
3922 Coverity, Inc. (http://scan.coverity.com).
3924 * When looking up multiply-defined global symbols, GDB will now prefer the
3925 symbol definition in the current shared library if it was built using the
3926 -Bsymbolic linker option.
3928 * When the Text User Interface (TUI) is not configured, GDB will now
3929 recognize the -tui command-line option and print a message that the TUI
3932 * The GDB remote stub, gdbserver, now has lower overhead for high
3933 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3935 * GDB for MIPS targets now autodetects whether a remote target provides
3936 32-bit or 64-bit register values.
3938 * Support for C++ member pointers has been improved.
3940 * GDB now understands XML target descriptions, which specify the
3941 target's overall architecture. GDB can read a description from
3942 a local file or over the remote serial protocol.
3944 * Vectors of single-byte data use a new integer type which is not
3945 automatically displayed as character or string data.
3947 * The /s format now works with the print command. It displays
3948 arrays of single-byte integers and pointers to single-byte integers
3951 * Target descriptions can now describe target-specific registers,
3952 for architectures which have implemented the support (currently
3953 only ARM, M68K, and MIPS).
3955 * GDB and the GDB remote stub, gdbserver, now support the XScale
3958 * The GDB remote stub, gdbserver, has been updated to support
3959 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3960 has been rewritten to use the standard GDB remote protocol.
3962 * GDB can now step into C++ functions which are called through thunks.
3964 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3966 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3967 layout. It also supports a TextSeg= and DataSeg= response when only
3968 segment base addresses (rather than offsets) are available.
3970 * The /i format now outputs any trailing branch delay slot instructions
3971 immediately following the last instruction within the count specified.
3973 * The GDB remote protocol "T" stop reply packet now supports a
3974 "library" response. Combined with the new "qXfer:libraries:read"
3975 packet, this response allows GDB to debug shared libraries on targets
3976 where the operating system manages the list of loaded libraries (e.g.
3977 Windows and SymbianOS).
3979 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3980 (DLLs) on Windows and Windows CE targets.
3982 * GDB now supports a faster verification that a .debug file matches its binary
3983 according to its build-id signature, if the signature is present.
3989 Enable or disable hardware flow control (RTS/CTS) on the serial port
3990 when debugging using remote targets.
3992 set mem inaccessible-by-default
3993 show mem inaccessible-by-default
3994 If the target supplies a memory map, for instance via the remote
3995 protocol's "qXfer:memory-map:read" packet, setting this variable
3996 prevents GDB from accessing memory outside the memory map. This
3997 is useful for targets with memory mapped registers or which react
3998 badly to accesses of unmapped address space.
4000 set breakpoint auto-hw
4001 show breakpoint auto-hw
4002 If the target supplies a memory map, for instance via the remote
4003 protocol's "qXfer:memory-map:read" packet, setting this variable
4004 lets GDB use hardware breakpoints automatically for memory regions
4005 where it can not use software breakpoints. This covers both the
4006 "break" command and internal breakpoints used for other commands
4007 including "next" and "finish".
4010 catch exception unhandled
4011 Stop the program execution when Ada exceptions are raised.
4014 Stop the program execution when an Ada assertion failed.
4018 Set an alternate system root for target files. This is a more
4019 general version of "set solib-absolute-prefix", which is now
4020 an alias to "set sysroot".
4023 Provide extended SPU facility status information. This set of
4024 commands is available only when debugging the Cell/B.E. SPU
4027 * New native configurations
4029 OpenBSD/sh sh*-*openbsd*
4032 unset tdesc filename
4034 Use the specified local file as an XML target description, and do
4035 not query the target for its built-in description.
4039 OpenBSD/sh sh*-*-openbsd*
4040 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4041 Toshiba Media Processor mep-elf
4043 * New remote packets
4046 Ignore the specified signals; pass them directly to the debugged program
4047 without stopping other threads or reporting them to GDB.
4049 qXfer:features:read:
4050 Read an XML target description from the target, which describes its
4055 Read or write contents of an spufs file on the target system. These
4056 packets are available only on the Cell/B.E. SPU architecture.
4058 qXfer:libraries:read:
4059 Report the loaded shared libraries. Combined with new "T" packet
4060 response, this packet allows GDB to debug shared libraries on
4061 targets where the operating system manages the list of loaded
4062 libraries (e.g. Windows and SymbianOS).
4066 Support for these obsolete configurations has been removed.
4074 i[34567]86-*-lynxos*
4075 i[34567]86-*-netware*
4076 i[34567]86-*-sco3.2v5*
4077 i[34567]86-*-sco3.2v4*
4079 i[34567]86-*-sysv4.2*
4082 i[34567]86-*-unixware2*
4083 i[34567]86-*-unixware*
4092 * Other removed features
4099 Various m68k-only ROM monitors.
4106 Various Renesas ROM monitors and debugging interfaces for SH and
4111 Support for a Macraigor serial interface to on-chip debugging.
4112 GDB does not directly support the newer parallel or USB
4117 A debug information format. The predecessor to DWARF 2 and
4118 DWARF 3, which are still supported.
4120 Support for the HP aCC compiler on HP-UX/PA-RISC
4122 SOM-encapsulated symbolic debugging information, automatic
4123 invocation of pxdb, and the aCC custom C++ ABI. This does not
4124 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4125 with aCC can still be debugged on an assembly level.
4127 MIPS ".pdr" sections
4129 A MIPS-specific format used to describe stack frame layout
4130 in debugging information.
4134 GDB could work with an older version of Guile to debug
4135 the interpreter and Scheme programs running in it.
4137 set mips stack-arg-size
4138 set mips saved-gpreg-size
4140 Use "set mips abi" to control parameter passing for MIPS.
4142 *** Changes in GDB 6.6
4147 Cell Broadband Engine SPU spu-elf
4149 * GDB can now be configured as a cross-debugger targeting native Windows
4150 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4151 running on a Windows system over TCP/IP to debug Windows programs.
4153 * The GDB remote stub, gdbserver, has been updated to support Windows and
4154 Cygwin debugging. Both single-threaded and multi-threaded programs are
4157 * The "set trust-readonly-sections" command works again. This command was
4158 broken in GDB 6.3, 6.4, and 6.5.
4160 * The "load" command now supports writing to flash memory, if the remote
4161 stub provides the required support.
4163 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4164 longer requires symbolic debug information (e.g. DWARF-2).
4169 unset substitute-path
4170 show substitute-path
4171 Manage a list of substitution rules that GDB uses to rewrite the name
4172 of the directories where the sources are located. This can be useful
4173 for instance when the sources were moved to a different location
4174 between compilation and debugging.
4178 Print each CLI command as it is executed. Each command is prefixed with
4179 a number of `+' symbols representing the nesting depth.
4180 The source command now has a `-v' option to enable the same feature.
4184 The ARM Demon monitor support (RDP protocol, "target rdp").
4186 Kernel Object Display, an embedded debugging feature which only worked with
4187 an obsolete version of Cisco IOS.
4189 The 'set download-write-size' and 'show download-write-size' commands.
4191 * New remote packets
4194 Tell a stub about GDB client features, and request remote target features.
4195 The first feature implemented is PacketSize, which allows the target to
4196 specify the size of packets it can handle - to minimize the number of
4197 packets required and improve performance when connected to a remote
4201 Fetch an OS auxilliary vector from the remote stub. This packet is a
4202 more efficient replacement for qPart:auxv:read.
4204 qXfer:memory-map:read:
4205 Fetch a memory map from the remote stub, including information about
4206 RAM, ROM, and flash memory devices.
4211 Erase and program a flash memory device.
4213 * Removed remote packets
4216 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4217 used it, and only gdbserver implemented it.
4219 *** Changes in GDB 6.5
4223 Renesas M32C/M16C m32c-elf
4225 Morpho Technologies ms1 ms1-elf
4229 init-if-undefined Initialize a convenience variable, but
4230 only if it doesn't already have a value.
4232 The following commands are presently only implemented for native GNU/Linux:
4234 checkpoint Save a snapshot of the program state.
4236 restart <n> Return the program state to a
4237 previously saved state.
4239 info checkpoints List currently saved checkpoints.
4241 delete-checkpoint <n> Delete a previously saved checkpoint.
4243 set|show detach-on-fork Tell gdb whether to detach from a newly
4244 forked process, or to keep debugging it.
4246 info forks List forks of the user program that
4247 are available to be debugged.
4249 fork <n> Switch to debugging one of several
4250 forks of the user program that are
4251 available to be debugged.
4253 delete-fork <n> Delete a fork from the list of forks
4254 that are available to be debugged (and
4255 kill the forked process).
4257 detach-fork <n> Delete a fork from the list of forks
4258 that are available to be debugged (and
4259 allow the process to continue).
4263 Morpho Technologies ms2 ms1-elf
4265 * Improved Windows host support
4267 GDB now builds as a cross debugger hosted on i686-mingw32, including
4268 native console support, and remote communications using either
4269 network sockets or serial ports.
4271 * Improved Modula-2 language support
4273 GDB can now print most types in the Modula-2 syntax. This includes:
4274 basic types, set types, record types, enumerated types, range types,
4275 pointer types and ARRAY types. Procedure var parameters are correctly
4276 printed and hexadecimal addresses and character constants are also
4277 written in the Modula-2 syntax. Best results can be obtained by using
4278 GNU Modula-2 together with the -gdwarf-2 command line option.
4282 The ARM rdi-share module.
4284 The Netware NLM debug server.
4286 *** Changes in GDB 6.4
4288 * New native configurations
4290 OpenBSD/arm arm*-*-openbsd*
4291 OpenBSD/mips64 mips64-*-openbsd*
4295 Morpho Technologies ms1 ms1-elf
4297 * New command line options
4299 --batch-silent As for --batch, but totally silent.
4300 --return-child-result The debugger will exist with the same value
4301 the child (debugged) program exited with.
4302 --eval-command COMMAND, -ex COMMAND
4303 Execute a single GDB CLI command. This may be
4304 specified multiple times and in conjunction
4305 with the --command (-x) option.
4307 * Deprecated commands removed
4309 The following commands, that were deprecated in 2000, have been
4313 set|show arm disassembly-flavor set|show arm disassembler
4314 othernames set arm disassembler
4315 set|show remotedebug set|show debug remote
4316 set|show archdebug set|show debug arch
4317 set|show eventdebug set|show debug event
4320 * New BSD user-level threads support
4322 It is now possible to debug programs using the user-level threads
4323 library on OpenBSD and FreeBSD. Currently supported (target)
4326 FreeBSD/amd64 x86_64-*-freebsd*
4327 FreeBSD/i386 i386-*-freebsd*
4328 OpenBSD/i386 i386-*-openbsd*
4330 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4331 are not yet supported.
4333 * New support for Matsushita MN10300 w/sim added
4334 (Work in progress). mn10300-elf.
4336 * REMOVED configurations and files
4338 VxWorks and the XDR protocol *-*-vxworks
4339 Motorola MCORE mcore-*-*
4340 National Semiconductor NS32000 ns32k-*-*
4342 * New "set print array-indexes" command
4344 After turning this setting "on", GDB prints the index of each element
4345 when displaying arrays. The default is "off" to preserve the previous
4348 * VAX floating point support
4350 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4352 * User-defined command support
4354 In addition to using $arg0..$arg9 for argument passing, it is now possible
4355 to use $argc to determine now many arguments have been passed. See the
4356 section on user-defined commands in the user manual for more information.
4358 *** Changes in GDB 6.3:
4360 * New command line option
4362 GDB now accepts -l followed by a number to set the timeout for remote
4365 * GDB works with GCC -feliminate-dwarf2-dups
4367 GDB now supports a more compact representation of DWARF-2 debug
4368 information using DW_FORM_ref_addr references. These are produced
4369 by GCC with the option -feliminate-dwarf2-dups and also by some
4370 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4371 to use -feliminate-dwarf2-dups.
4373 * Internationalization
4375 When supported by the host system, GDB will be built with
4376 internationalization (libintl). The task of marking up the sources is
4377 continued, we're looking forward to our first translation.
4381 Initial support for debugging programs compiled with the GNAT
4382 implementation of the Ada programming language has been integrated
4383 into GDB. In this release, support is limited to expression evaluation.
4385 * New native configurations
4387 GNU/Linux/m32r m32r-*-linux-gnu
4391 GDB's remote protocol now includes support for the 'p' packet. This
4392 packet is used to fetch individual registers from a remote inferior.
4394 * END-OF-LIFE registers[] compatibility module
4396 GDB's internal register infrastructure has been completely rewritten.
4397 The new infrastructure making possible the implementation of key new
4398 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4401 GDB 6.3 will be the last release to include the the registers[]
4402 compatibility module that allowed out-of-date configurations to
4403 continue to work. This change directly impacts the following
4413 powerpc bdm protocol
4415 Unless there is activity to revive these configurations, they will be
4416 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4418 * OBSOLETE configurations and files
4420 Configurations that have been declared obsolete in this release have
4421 been commented out. Unless there is activity to revive these
4422 configurations, the next release of GDB will have their sources
4423 permanently REMOVED.
4432 *** Changes in GDB 6.2.1:
4434 * MIPS `break main; run' gave an heuristic-fence-post warning
4436 When attempting to run even a simple program, a warning about
4437 heuristic-fence-post being hit would be reported. This problem has
4440 * MIPS IRIX 'long double' crashed GDB
4442 When examining a long double variable, GDB would get a segmentation
4443 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4444 IRIX long double values).
4448 A bug in the VAX stack code was causing problems with the "next"
4449 command. This problem has been fixed.
4451 *** Changes in GDB 6.2:
4453 * Fix for ``many threads''
4455 On GNU/Linux systems that use the NPTL threads library, a program
4456 rapidly creating and deleting threads would confuse GDB leading to the
4459 ptrace: No such process.
4460 thread_db_get_info: cannot get thread info: generic error
4462 This problem has been fixed.
4464 * "-async" and "-noasync" options removed.
4466 Support for the broken "-noasync" option has been removed (it caused
4469 * New ``start'' command.
4471 This command runs the program until the begining of the main procedure.
4473 * New BSD Kernel Data Access Library (libkvm) interface
4475 Using ``target kvm'' it is now possible to debug kernel core dumps and
4476 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4477 platforms. Currently supported (native-only) configurations are:
4479 FreeBSD/amd64 x86_64-*-freebsd*
4480 FreeBSD/i386 i?86-*-freebsd*
4481 NetBSD/i386 i?86-*-netbsd*
4482 NetBSD/m68k m68*-*-netbsd*
4483 NetBSD/sparc sparc-*-netbsd*
4484 OpenBSD/amd64 x86_64-*-openbsd*
4485 OpenBSD/i386 i?86-*-openbsd*
4486 OpenBSD/m68k m68*-openbsd*
4487 OpenBSD/sparc sparc-*-openbsd*
4489 * Signal trampoline code overhauled
4491 Many generic problems with GDB's signal handling code have been fixed.
4492 These include: backtraces through non-contiguous stacks; recognition
4493 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4494 call; backtrace through a signal trampoline; step into and out of
4495 signal handlers; and single-stepping in the signal trampoline.
4497 Please note that kernel bugs are a limiting factor here. These
4498 features have been shown to work on an s390 GNU/Linux system that
4499 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4501 * Cygwin support for DWARF 2 added.
4503 * New native configurations
4505 GNU/Linux/hppa hppa*-*-linux*
4506 OpenBSD/hppa hppa*-*-openbsd*
4507 OpenBSD/m68k m68*-*-openbsd*
4508 OpenBSD/m88k m88*-*-openbsd*
4509 OpenBSD/powerpc powerpc-*-openbsd*
4510 NetBSD/vax vax-*-netbsd*
4511 OpenBSD/vax vax-*-openbsd*
4513 * END-OF-LIFE frame compatibility module
4515 GDB's internal frame infrastructure has been completely rewritten.
4516 The new infrastructure making it possible to support key new features
4517 including DWARF 2 Call Frame Information. To aid in the task of
4518 migrating old configurations to this new infrastructure, a
4519 compatibility module, that allowed old configurations to continue to
4520 work, was also included.
4522 GDB 6.2 will be the last release to include this frame compatibility
4523 module. This change directly impacts the following configurations:
4533 Unless there is activity to revive these configurations, they will be
4534 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4536 * REMOVED configurations and files
4538 Sun 3, running SunOS 3 m68*-*-sunos3*
4539 Sun 3, running SunOS 4 m68*-*-sunos4*
4540 Sun 2, running SunOS 3 m68000-*-sunos3*
4541 Sun 2, running SunOS 4 m68000-*-sunos4*
4542 Motorola 680x0 running LynxOS m68*-*-lynxos*
4543 AT&T 3b1/Unix pc m68*-att-*
4544 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4545 decstation mips-dec-* mips-little-*
4546 riscos mips-*-riscos* mips-*-sysv*
4547 sonymips mips-sony-*
4548 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4550 *** Changes in GDB 6.1.1:
4552 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4554 The TUI (Text-mode User Interface) is now built as part of a default
4555 GDB configuration. It is enabled by either selecting the TUI with the
4556 command line option "-i=tui" or by running the separate "gdbtui"
4557 program. For more information on the TUI, see the manual "Debugging
4560 * Pending breakpoint support (also included in GDB 6.1)
4562 Support has been added to allow you to specify breakpoints in shared
4563 libraries that have not yet been loaded. If a breakpoint location
4564 cannot be found, and the "breakpoint pending" option is set to auto,
4565 GDB queries you if you wish to make the breakpoint pending on a future
4566 shared-library load. If and when GDB resolves the breakpoint symbol,
4567 the pending breakpoint is removed as one or more regular breakpoints
4570 Pending breakpoints are very useful for GCJ Java debugging.
4572 * Fixed ISO-C build problems
4574 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4575 non ISO-C code that stopped them being built using a more strict ISO-C
4576 compiler (e.g., IBM's C compiler).
4578 * Fixed build problem on IRIX 5
4580 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4581 wasn't able to compile compile on an IRIX 5 system.
4583 * Added execute permission to gdb/gdbserver/configure
4585 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4586 permission. This bug would cause configure to fail on a number of
4587 systems (Solaris, IRIX). Ref: server/519.
4589 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4591 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4592 has been updated to use constant array sizes.
4594 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4596 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4597 its generated DWARF Call Frame Info. This encoding was causing GDB to
4598 panic, that panic has been fixed. Ref: gdb/1628.
4600 * Fixed a problem when examining parameters in shared library code.
4602 When examining parameters in optimized shared library code generated
4603 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4604 not available''. GDB now correctly displays the variable's value.
4606 *** Changes in GDB 6.1:
4608 * Removed --with-mmalloc
4610 Support for the mmalloc memory manager has been removed, as it
4611 conflicted with the internal gdb byte cache.
4613 * Changes in AMD64 configurations
4615 The AMD64 target now includes the %cs and %ss registers. As a result
4616 the AMD64 remote protocol has changed; this affects the floating-point
4617 and SSE registers. If you rely on those registers for your debugging,
4618 you should upgrade gdbserver on the remote side.
4620 * Revised SPARC target
4622 The SPARC target has been completely revised, incorporating the
4623 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4624 support for LynxOS and SunOS 4 has been dropped. Calling functions
4625 from within GDB on operating systems with a non-executable stack
4626 (Solaris, OpenBSD) now works.
4630 GDB has a new C++ demangler which does a better job on the mangled
4631 names generated by current versions of g++. It also runs faster, so
4632 with this and other changes gdb should now start faster on large C++
4635 * DWARF 2 Location Expressions
4637 GDB support for location expressions has been extended to support function
4638 arguments and frame bases. Older versions of GDB could crash when they
4641 * C++ nested types and namespaces
4643 GDB's support for nested types and namespaces in C++ has been
4644 improved, especially if you use the DWARF 2 debugging format. (This
4645 is the default for recent versions of GCC on most platforms.)
4646 Specifically, if you have a class "Inner" defined within a class or
4647 namespace "Outer", then GDB realizes that the class's name is
4648 "Outer::Inner", not simply "Inner". This should greatly reduce the
4649 frequency of complaints about not finding RTTI symbols. In addition,
4650 if you are stopped at inside of a function defined within a namespace,
4651 GDB modifies its name lookup accordingly.
4653 * New native configurations
4655 NetBSD/amd64 x86_64-*-netbsd*
4656 OpenBSD/amd64 x86_64-*-openbsd*
4657 OpenBSD/alpha alpha*-*-openbsd*
4658 OpenBSD/sparc sparc-*-openbsd*
4659 OpenBSD/sparc64 sparc64-*-openbsd*
4661 * New debugging protocols
4663 M32R with SDI protocol m32r-*-elf*
4665 * "set prompt-escape-char" command deleted.
4667 The command "set prompt-escape-char" has been deleted. This command,
4668 and its very obscure effet on GDB's prompt, was never documented,
4669 tested, nor mentioned in the NEWS file.
4671 * OBSOLETE configurations and files
4673 Configurations that have been declared obsolete in this release have
4674 been commented out. Unless there is activity to revive these
4675 configurations, the next release of GDB will have their sources
4676 permanently REMOVED.
4678 Sun 3, running SunOS 3 m68*-*-sunos3*
4679 Sun 3, running SunOS 4 m68*-*-sunos4*
4680 Sun 2, running SunOS 3 m68000-*-sunos3*
4681 Sun 2, running SunOS 4 m68000-*-sunos4*
4682 Motorola 680x0 running LynxOS m68*-*-lynxos*
4683 AT&T 3b1/Unix pc m68*-att-*
4684 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4685 decstation mips-dec-* mips-little-*
4686 riscos mips-*-riscos* mips-*-sysv*
4687 sonymips mips-sony-*
4688 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4690 * REMOVED configurations and files
4692 SGI Irix-4.x mips-sgi-irix4 or iris4
4693 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4694 Z8000 simulator z8k-zilog-none or z8ksim
4695 Matsushita MN10200 w/simulator mn10200-*-*
4696 H8/500 simulator h8500-hitachi-hms or h8500hms
4697 HP/PA running BSD hppa*-*-bsd*
4698 HP/PA running OSF/1 hppa*-*-osf*
4699 HP/PA Pro target hppa*-*-pro*
4700 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4701 386BSD i[3456]86-*-bsd*
4702 Sequent family i[3456]86-sequent-sysv4*
4703 i[3456]86-sequent-sysv*
4704 i[3456]86-sequent-bsd*
4705 SPARC running LynxOS sparc-*-lynxos*
4706 SPARC running SunOS 4 sparc-*-sunos4*
4707 Tsqware Sparclet sparclet-*-*
4708 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4710 *** Changes in GDB 6.0:
4714 Support for debugging the Objective-C programming language has been
4715 integrated into GDB.
4717 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4719 DWARF 2's Call Frame Information makes available compiler generated
4720 information that more exactly describes the program's run-time stack.
4721 By using this information, GDB is able to provide more robust stack
4724 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4725 have been updated to use a new backtrace mechanism which includes
4726 DWARF 2 CFI support.
4730 GDB's remote protocol has been extended to include support for hosted
4731 file I/O (where the remote target uses GDB's file system). See GDB's
4732 remote protocol documentation for details.
4734 * All targets using the new architecture framework.
4736 All of GDB's targets have been updated to use the new internal
4737 architecture framework. The way is now open for future GDB releases
4738 to include cross-architecture native debugging support (i386 on amd64,
4741 * GNU/Linux's Thread Local Storage (TLS)
4743 GDB now includes support for for the GNU/Linux implementation of
4744 per-thread variables.
4746 * GNU/Linux's Native POSIX Thread Library (NPTL)
4748 GDB's thread code has been updated to work with either the new
4749 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4751 * Separate debug info.
4753 GDB, in conjunction with BINUTILS, now supports a mechanism for
4754 automatically loading debug information from a separate file. Instead
4755 of shipping full debug and non-debug versions of system libraries,
4756 system integrators can now instead ship just the stripped libraries
4757 and optional debug files.
4759 * DWARF 2 Location Expressions
4761 DWARF 2 Location Expressions allow the compiler to more completely
4762 describe the location of variables (even in optimized code) to the
4765 GDB now includes preliminary support for location expressions (support
4766 for DW_OP_piece is still missing).
4770 A number of long standing bugs that caused GDB to die while starting a
4771 Java application have been fixed. GDB's Java support is now
4772 considered "useable".
4774 * GNU/Linux support for fork, vfork, and exec.
4776 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4777 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4780 * GDB supports logging output to a file
4782 There are two new commands, "set logging" and "show logging", which can be
4783 used to capture GDB's output to a file.
4785 * The meaning of "detach" has changed for gdbserver
4787 The "detach" command will now resume the application, as documented. To
4788 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4791 * d10v, m68hc11 `regs' command deprecated
4793 The `info registers' command has been updated so that it displays the
4794 registers using a format identical to the old `regs' command.
4798 A new command, "maint set profile on/off", has been added. This command can
4799 be used to enable or disable profiling while running GDB, to profile a
4800 session or a set of commands. In addition there is a new configure switch,
4801 "--enable-profiling", which will cause GDB to be compiled with profiling
4802 data, for more informative profiling results.
4804 * Default MI syntax changed to "mi2".
4806 The default MI (machine interface) syntax, enabled by the command line
4807 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4808 "mi1", can be enabled by specifying the option "-i=mi1".
4810 Support for the original "mi0" syntax (included in GDB 5.0) has been
4813 Fix for gdb/192: removed extraneous space when displaying frame level.
4814 Fix for gdb/672: update changelist is now output in mi list format.
4815 Fix for gdb/702: a -var-assign that updates the value now shows up
4816 in a subsequent -var-update.
4818 * New native configurations.
4820 FreeBSD/amd64 x86_64-*-freebsd*
4822 * Multi-arched targets.
4824 HP/PA HPUX11 hppa*-*-hpux*
4825 Renesas M32R/D w/simulator m32r-*-elf*
4827 * OBSOLETE configurations and files
4829 Configurations that have been declared obsolete in this release have
4830 been commented out. Unless there is activity to revive these
4831 configurations, the next release of GDB will have their sources
4832 permanently REMOVED.
4834 Z8000 simulator z8k-zilog-none or z8ksim
4835 Matsushita MN10200 w/simulator mn10200-*-*
4836 H8/500 simulator h8500-hitachi-hms or h8500hms
4837 HP/PA running BSD hppa*-*-bsd*
4838 HP/PA running OSF/1 hppa*-*-osf*
4839 HP/PA Pro target hppa*-*-pro*
4840 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4841 Sequent family i[3456]86-sequent-sysv4*
4842 i[3456]86-sequent-sysv*
4843 i[3456]86-sequent-bsd*
4844 Tsqware Sparclet sparclet-*-*
4845 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4847 * REMOVED configurations and files
4850 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4851 IBM AIX PS/2 i[3456]86-*-aix
4852 i386 running Mach 3.0 i[3456]86-*-mach3*
4853 i386 running Mach i[3456]86-*-mach*
4854 i386 running OSF/1 i[3456]86-*osf1mk*
4855 HP/Apollo 68k Family m68*-apollo*-sysv*,
4857 m68*-hp-bsd*, m68*-hp-hpux*
4858 Argonaut Risc Chip (ARC) arc-*-*
4859 Mitsubishi D30V d30v-*-*
4860 Fujitsu FR30 fr30-*-elf*
4861 OS/9000 i[34]86-*-os9k
4862 I960 with MON960 i960-*-coff
4864 * MIPS $fp behavior changed
4866 The convenience variable $fp, for the MIPS, now consistently returns
4867 the address of the current frame's base. Previously, depending on the
4868 context, $fp could refer to either $sp or the current frame's base
4869 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4870 The GNU Source-Level Debugger''.
4872 *** Changes in GDB 5.3:
4874 * GNU/Linux shared library multi-threaded performance improved.
4876 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4877 `/proc', in preference to `ptrace' for memory reads. This may result
4878 in an improvement in the start-up time of multi-threaded, shared
4879 library applications when run under GDB. One GDB user writes: ``loads
4880 shared libs like mad''.
4882 * ``gdbserver'' now supports multi-threaded applications on some targets
4884 Support for debugging multi-threaded applications which use
4885 the GNU/Linux LinuxThreads package has been added for
4886 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4887 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4889 * GDB now supports C/C++ preprocessor macros.
4891 GDB now expands preprocessor macro invocations in C/C++ expressions,
4892 and provides various commands for showing macro definitions and how
4895 The new command `macro expand EXPRESSION' expands any macro
4896 invocations in expression, and shows the result.
4898 The new command `show macro MACRO-NAME' shows the definition of the
4899 macro named MACRO-NAME, and where it was defined.
4901 Most compilers don't include information about macros in the debugging
4902 information by default. In GCC 3.1, for example, you need to compile
4903 your program with the options `-gdwarf-2 -g3'. If the macro
4904 information is present in the executable, GDB will read it.
4906 * Multi-arched targets.
4908 DEC Alpha (partial) alpha*-*-*
4909 DEC VAX (partial) vax-*-*
4911 National Semiconductor NS32000 (partial) ns32k-*-*
4912 Motorola 68000 (partial) m68k-*-*
4913 Motorola MCORE mcore-*-*
4917 Fujitsu FRV architecture added by Red Hat frv*-*-*
4920 * New native configurations
4922 Alpha NetBSD alpha*-*-netbsd*
4923 SH NetBSD sh*-*-netbsdelf*
4924 MIPS NetBSD mips*-*-netbsd*
4925 UltraSPARC NetBSD sparc64-*-netbsd*
4927 * OBSOLETE configurations and files
4929 Configurations that have been declared obsolete in this release have
4930 been commented out. Unless there is activity to revive these
4931 configurations, the next release of GDB will have their sources
4932 permanently REMOVED.
4934 Mitsubishi D30V d30v-*-*
4935 OS/9000 i[34]86-*-os9k
4936 IBM AIX PS/2 i[3456]86-*-aix
4937 Fujitsu FR30 fr30-*-elf*
4938 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4939 Argonaut Risc Chip (ARC) arc-*-*
4940 i386 running Mach 3.0 i[3456]86-*-mach3*
4941 i386 running Mach i[3456]86-*-mach*
4942 i386 running OSF/1 i[3456]86-*osf1mk*
4943 HP/Apollo 68k Family m68*-apollo*-sysv*,
4945 m68*-hp-bsd*, m68*-hp-hpux*
4946 I960 with MON960 i960-*-coff
4948 * OBSOLETE languages
4950 CHILL, a Pascal like language used by telecommunications companies.
4952 * REMOVED configurations and files
4954 AMD 29k family via UDI a29k-amd-udi, udi29k
4955 A29K VxWorks a29k-*-vxworks
4956 AMD 29000 embedded, using EBMON a29k-none-none
4957 AMD 29000 embedded with COFF a29k-none-coff
4958 AMD 29000 embedded with a.out a29k-none-aout
4960 testsuite/gdb.hp/gdb.threads-hp/ directory
4962 * New command "set max-user-call-depth <nnn>"
4964 This command allows the user to limit the call depth of user-defined
4965 commands. The default is 1024.
4967 * Changes in FreeBSD/i386 native debugging.
4969 Support for the "generate-core-file" has been added.
4971 * New commands "dump", "append", and "restore".
4973 These commands allow data to be copied from target memory
4974 to a bfd-format or binary file (dump and append), and back
4975 from a file into memory (restore).
4977 * Improved "next/step" support on multi-processor Alpha Tru64.
4979 The previous single-step mechanism could cause unpredictable problems,
4980 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4981 of a software single-step mechanism prevents this.
4983 *** Changes in GDB 5.2.1:
4991 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4992 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4993 Fix, by Joel Brobecker imported from mainline.
4995 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4996 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4997 Fix, by Fred Fish, imported from mainline.
4999 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5000 Surprisingly enough, it works now.
5001 By Michal Ludvig, imported from mainline.
5003 i386 hardware watchpoint support:
5004 avoid misses on second run for some targets.
5005 By Pierre Muller, imported from mainline.
5007 *** Changes in GDB 5.2:
5009 * New command "set trust-readonly-sections on[off]".
5011 This command is a hint that tells gdb that read-only sections
5012 really are read-only (ie. that their contents will not change).
5013 In this mode, gdb will go to the object file rather than the
5014 target to read memory from read-only sections (such as ".text").
5015 This can be a significant performance improvement on some
5016 (notably embedded) targets.
5018 * New command "generate-core-file" (or "gcore").
5020 This new gdb command allows the user to drop a core file of the child
5021 process state at any time. So far it's been implemented only for
5022 GNU/Linux and Solaris, but should be relatively easily ported to other
5023 hosts. Argument is core file name (defaults to core.<pid>).
5025 * New command line option
5027 GDB now accepts --pid or -p followed by a process id.
5029 * Change in command line behavior -- corefiles vs. process ids.
5031 There is a subtle behavior in the way in which GDB handles
5032 command line arguments. The first non-flag argument is always
5033 a program to debug, but the second non-flag argument may either
5034 be a corefile or a process id. Previously, GDB would attempt to
5035 open the second argument as a corefile, and if that failed, would
5036 issue a superfluous error message and then attempt to attach it as
5037 a process. Now, if the second argument begins with a non-digit,
5038 it will be treated as a corefile. If it begins with a digit,
5039 GDB will attempt to attach it as a process, and if no such process
5040 is found, will then attempt to open it as a corefile.
5042 * Changes in ARM configurations.
5044 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5045 configuration is fully multi-arch.
5047 * New native configurations
5049 ARM NetBSD arm*-*-netbsd*
5050 x86 OpenBSD i[3456]86-*-openbsd*
5051 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5052 Sparc64 running FreeBSD sparc64-*-freebsd*
5056 Sanyo XStormy16 xstormy16-elf
5058 * OBSOLETE configurations and files
5060 Configurations that have been declared obsolete in this release have
5061 been commented out. Unless there is activity to revive these
5062 configurations, the next release of GDB will have their sources
5063 permanently REMOVED.
5065 AMD 29k family via UDI a29k-amd-udi, udi29k
5066 A29K VxWorks a29k-*-vxworks
5067 AMD 29000 embedded, using EBMON a29k-none-none
5068 AMD 29000 embedded with COFF a29k-none-coff
5069 AMD 29000 embedded with a.out a29k-none-aout
5071 testsuite/gdb.hp/gdb.threads-hp/ directory
5073 * REMOVED configurations and files
5075 TI TMS320C80 tic80-*-*
5077 PowerPC Solaris powerpcle-*-solaris*
5078 PowerPC Windows NT powerpcle-*-cygwin32
5079 PowerPC Netware powerpc-*-netware*
5080 Harris/CXUX m88k m88*-harris-cxux*
5081 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5082 ns32k-utek-sysv* ns32k-utek-*
5083 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5084 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5085 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5086 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5087 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5089 * Changes to command line processing
5091 The new `--args' feature can be used to specify command-line arguments
5092 for the inferior from gdb's command line.
5094 * Changes to key bindings
5096 There is a new `operate-and-get-next' function bound to `C-o'.
5098 *** Changes in GDB 5.1.1
5100 Fix compile problem on DJGPP.
5102 Fix a problem with floating-point registers on the i386 being
5105 Fix to stop GDB crashing on .debug_str debug info.
5107 Numerous documentation fixes.
5109 Numerous testsuite fixes.
5111 *** Changes in GDB 5.1:
5113 * New native configurations
5115 Alpha FreeBSD alpha*-*-freebsd*
5116 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5117 MIPS GNU/Linux mips*-*-linux*
5118 MIPS SGI Irix 6.x mips*-sgi-irix6*
5119 ia64 AIX ia64-*-aix*
5120 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5124 Motorola 68HC11 and 68HC12 m68hc11-elf
5126 UltraSparc running GNU/Linux sparc64-*-linux*
5128 * OBSOLETE configurations and files
5130 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5131 Harris/CXUX m88k m88*-harris-cxux*
5132 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5133 ns32k-utek-sysv* ns32k-utek-*
5134 TI TMS320C80 tic80-*-*
5136 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5137 PowerPC Solaris powerpcle-*-solaris*
5138 PowerPC Windows NT powerpcle-*-cygwin32
5139 PowerPC Netware powerpc-*-netware*
5140 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5141 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5142 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5143 Apple Macintosh (MPW) host N/A
5145 stuff.c (Program to stuff files into a specially prepared space in kdb)
5146 kdb-start.c (Main loop for the standalone kernel debugger)
5148 Configurations that have been declared obsolete in this release have
5149 been commented out. Unless there is activity to revive these
5150 configurations, the next release of GDB will have their sources
5151 permanently REMOVED.
5153 * REMOVED configurations and files
5155 Altos 3068 m68*-altos-*
5156 Convex c1-*-*, c2-*-*
5158 ARM RISCix arm-*-* (as host)
5162 * GDB has been converted to ISO C.
5164 GDB's source code has been converted to ISO C. In particular, the
5165 sources are fully protoized, and rely on standard headers being
5170 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5172 * The MI enabled by default.
5174 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5175 revised and enabled by default. Packages which use GDB as a debugging
5176 engine behind a UI or another front end are encouraged to switch to
5177 using the GDB/MI interface, instead of the old annotations interface
5178 which is now deprecated.
5180 * Support for debugging Pascal programs.
5182 GDB now includes support for debugging Pascal programs. The following
5183 main features are supported:
5185 - Pascal-specific data types such as sets;
5187 - automatic recognition of Pascal sources based on file-name
5190 - Pascal-style display of data types, variables, and functions;
5192 - a Pascal expression parser.
5194 However, some important features are not yet supported.
5196 - Pascal string operations are not supported at all;
5198 - there are some problems with boolean types;
5200 - Pascal type hexadecimal constants are not supported
5201 because they conflict with the internal variables format;
5203 - support for Pascal objects and classes is not full yet;
5205 - unlike Pascal, GDB is case-sensitive for symbol names.
5207 * Changes in completion.
5209 Commands such as `shell', `run' and `set args', which pass arguments
5210 to inferior programs, now complete on file names, similar to what
5211 users expect at the shell prompt.
5213 Commands which accept locations, such as `disassemble', `print',
5214 `breakpoint', `until', etc. now complete on filenames as well as
5215 program symbols. Thus, if you type "break foob TAB", and the source
5216 files linked into the programs include `foobar.c', that file name will
5217 be one of the candidates for completion. However, file names are not
5218 considered for completion after you typed a colon that delimits a file
5219 name from a name of a function in that file, as in "break foo.c:bar".
5221 `set demangle-style' completes on available demangling styles.
5223 * New platform-independent commands:
5225 It is now possible to define a post-hook for a command as well as a
5226 hook that runs before the command. For more details, see the
5227 documentation of `hookpost' in the GDB manual.
5229 * Changes in GNU/Linux native debugging.
5231 Support for debugging multi-threaded programs has been completely
5232 revised for all platforms except m68k and sparc. You can now debug as
5233 many threads as your system allows you to have.
5235 Attach/detach is supported for multi-threaded programs.
5237 Support for SSE registers was added for x86. This doesn't work for
5238 multi-threaded programs though.
5240 * Changes in MIPS configurations.
5242 Multi-arch support is enabled for all MIPS configurations.
5244 GDB can now be built as native debugger on SGI Irix 6.x systems for
5245 debugging n32 executables. (Debugging 64-bit executables is not yet
5248 * Unified support for hardware watchpoints in all x86 configurations.
5250 Most (if not all) native x86 configurations support hardware-assisted
5251 breakpoints and watchpoints in a unified manner. This support
5252 implements debug register sharing between watchpoints, which allows to
5253 put a virtually infinite number of watchpoints on the same address,
5254 and also supports watching regions up to 16 bytes with several debug
5257 The new maintenance command `maintenance show-debug-regs' toggles
5258 debugging print-outs in functions that insert, remove, and test
5259 watchpoints and hardware breakpoints.
5261 * Changes in the DJGPP native configuration.
5263 New command ``info dos sysinfo'' displays assorted information about
5264 the CPU, OS, memory, and DPMI server.
5266 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5267 display information about segment descriptors stored in GDT, LDT, and
5270 New commands ``info dos pde'' and ``info dos pte'' display entries
5271 from Page Directory and Page Tables (for now works with CWSDPMI only).
5272 New command ``info dos address-pte'' displays the Page Table entry for
5273 a given linear address.
5275 GDB can now pass command lines longer than 126 characters to the
5276 program being debugged (requires an update to the libdbg.a library
5277 which is part of the DJGPP development kit).
5279 DWARF2 debug info is now supported.
5281 It is now possible to `step' and `next' through calls to `longjmp'.
5283 * Changes in documentation.
5285 All GDB documentation was converted to GFDL, the GNU Free
5286 Documentation License.
5288 Tracepoints-related commands are now fully documented in the GDB
5291 TUI, the Text-mode User Interface, is now documented in the manual.
5293 Tracepoints-related commands are now fully documented in the GDB
5296 The "GDB Internals" manual now has an index. It also includes
5297 documentation of `ui_out' functions, GDB coding standards, x86
5298 hardware watchpoints, and memory region attributes.
5300 * GDB's version number moved to ``version.in''
5302 The Makefile variable VERSION has been replaced by the file
5303 ``version.in''. People creating GDB distributions should update the
5304 contents of this file.
5308 GUD support is now a standard part of the EMACS distribution.
5310 *** Changes in GDB 5.0:
5312 * Improved support for debugging FP programs on x86 targets
5314 Unified and much-improved support for debugging floating-point
5315 programs on all x86 targets. In particular, ``info float'' now
5316 displays the FP registers in the same format on all x86 targets, with
5317 greater level of detail.
5319 * Improvements and bugfixes in hardware-assisted watchpoints
5321 It is now possible to watch array elements, struct members, and
5322 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5323 on x86 targets no longer erroneously trigger when the address is
5326 * Improvements in the native DJGPP version of GDB
5328 The distribution now includes all the scripts and auxiliary files
5329 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5330 machines ``out of the box''.
5332 The DJGPP version can now debug programs that use signals. It is
5333 possible to catch signals that happened in the debuggee, deliver
5334 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5335 would kill the program being debugged.) Programs that hook hardware
5336 interrupts (keyboard, timer, etc.) can also be debugged.
5338 It is now possible to debug DJGPP programs that redirect their
5339 standard handles or switch them to raw (as opposed to cooked) mode, or
5340 even close them. The command ``run < foo > bar'' works as expected,
5341 and ``info terminal'' reports useful information about the debuggee's
5342 terminal, including raw/cooked mode, redirection, etc.
5344 The DJGPP version now uses termios functions for console I/O, which
5345 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5348 DOS-style file names with drive letters are now fully supported by
5351 It is now possible to debug DJGPP programs that switch their working
5352 directory. It is also possible to rerun the debuggee any number of
5353 times without restarting GDB; thus, you can use the same setup,
5354 breakpoints, etc. for many debugging sessions.
5356 * New native configurations
5358 ARM GNU/Linux arm*-*-linux*
5359 PowerPC GNU/Linux powerpc-*-linux*
5363 Motorola MCore mcore-*-*
5364 x86 VxWorks i[3456]86-*-vxworks*
5365 PowerPC VxWorks powerpc-*-vxworks*
5366 TI TMS320C80 tic80-*-*
5368 * OBSOLETE configurations
5370 Altos 3068 m68*-altos-*
5371 Convex c1-*-*, c2-*-*
5373 ARM RISCix arm-*-* (as host)
5376 Configurations that have been declared obsolete will be commented out,
5377 but the code will be left in place. If there is no activity to revive
5378 these configurations before the next release of GDB, the sources will
5379 be permanently REMOVED.
5381 * Gould support removed
5383 Support for the Gould PowerNode and NP1 has been removed.
5385 * New features for SVR4
5387 On SVR4 native platforms (such as Solaris), if you attach to a process
5388 without first loading a symbol file, GDB will now attempt to locate and
5389 load symbols from the running process's executable file.
5391 * Many C++ enhancements
5393 C++ support has been greatly improved. Overload resolution now works properly
5394 in almost all cases. RTTI support is on the way.
5396 * Remote targets can connect to a sub-program
5398 A popen(3) style serial-device has been added. This device starts a
5399 sub-process (such as a stand-alone simulator) and then communicates
5400 with that. The sub-program to run is specified using the syntax
5401 ``|<program> <args>'' vis:
5403 (gdb) set remotedebug 1
5404 (gdb) target extended-remote |mn10300-elf-sim program-args
5406 * MIPS 64 remote protocol
5408 A long standing bug in the mips64 remote protocol where by GDB
5409 expected certain 32 bit registers (ex SR) to be transfered as 32
5410 instead of 64 bits has been fixed.
5412 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5413 added to provide backward compatibility with older versions of GDB.
5415 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5417 The command ``set remotebinarydownload'' command has been replaced by
5418 ``set remote X-packet''. Other commands in ``set remote'' family
5419 include ``set remote P-packet''.
5421 * Breakpoint commands accept ranges.
5423 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5424 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5425 ``tracepoint passcount'' also accepts a range of tracepoints.
5427 * ``apropos'' command added.
5429 The ``apropos'' command searches through command names and
5430 documentation strings, printing out matches, making it much easier to
5431 try to find a command that does what you are looking for.
5435 A new machine oriented interface (MI) has been added to GDB. This
5436 interface is designed for debug environments running GDB as a separate
5437 process. This is part of the long term libGDB project. See the
5438 "GDB/MI" chapter of the GDB manual for further information. It can be
5439 enabled by configuring with:
5441 .../configure --enable-gdbmi
5443 *** Changes in GDB-4.18:
5445 * New native configurations
5447 HP-UX 10.20 hppa*-*-hpux10.20
5448 HP-UX 11.x hppa*-*-hpux11.0*
5449 M68K GNU/Linux m68*-*-linux*
5453 Fujitsu FR30 fr30-*-elf*
5454 Intel StrongARM strongarm-*-*
5455 Mitsubishi D30V d30v-*-*
5457 * OBSOLETE configurations
5459 Gould PowerNode, NP1 np1-*-*, pn-*-*
5461 Configurations that have been declared obsolete will be commented out,
5462 but the code will be left in place. If there is no activity to revive
5463 these configurations before the next release of GDB, the sources will
5464 be permanently REMOVED.
5468 As a compatibility experiment, GDB's source files buildsym.h and
5469 buildsym.c have been converted to pure standard C, no longer
5470 containing any K&R compatibility code. We believe that all systems in
5471 use today either come with a standard C compiler, or have a GCC port
5472 available. If this is not true, please report the affected
5473 configuration to bug-gdb@gnu.org immediately. See the README file for
5474 information about getting a standard C compiler if you don't have one
5479 GDB now uses readline 2.2.
5481 * set extension-language
5483 You can now control the mapping between filename extensions and source
5484 languages by using the `set extension-language' command. For instance,
5485 you can ask GDB to treat .c files as C++ by saying
5486 set extension-language .c c++
5487 The command `info extensions' lists all of the recognized extensions
5488 and their associated languages.
5490 * Setting processor type for PowerPC and RS/6000
5492 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5493 you can use the `set processor' command to specify what variant of the
5494 PowerPC family you are debugging. The command
5498 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5499 following PowerPC and RS6000 variants:
5501 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5502 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5504 403GC IBM PowerPC 403GC
5505 505 Motorola PowerPC 505
5506 860 Motorola PowerPC 860 or 850
5507 601 Motorola PowerPC 601
5508 602 Motorola PowerPC 602
5509 603 Motorola/IBM PowerPC 603 or 603e
5510 604 Motorola PowerPC 604 or 604e
5511 750 Motorola/IBM PowerPC 750 or 750
5513 At the moment, this command just tells GDB what to name the
5514 special-purpose processor registers. Since almost all the affected
5515 registers are inaccessible to user-level programs, this command is
5516 only useful for remote debugging in its present form.
5520 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5521 more extensive support for HP-UX. Added features include shared
5522 library support, kernel threads and hardware watchpoints for 11.00,
5523 support for HP's ANSI C and C++ compilers, and a compatibility mode
5524 for xdb and dbx commands.
5528 HP's donation includes the new concept of catchpoints, which is a
5529 generalization of the old catch command. On HP-UX, it is now possible
5530 to catch exec, fork, and vfork, as well as library loading.
5532 This means that the existing catch command has changed; its first
5533 argument now specifies the type of catch to be set up. See the
5534 output of "help catch" for a list of catchpoint types.
5536 * Debugging across forks
5538 On HP-UX, you can choose which process to debug when a fork() happens
5543 HP has donated a curses-based terminal user interface (TUI). To get
5544 it, build with --enable-tui. Although this can be enabled for any
5545 configuration, at present it only works for native HP debugging.
5547 * GDB remote protocol additions
5549 A new protocol packet 'X' that writes binary data is now available.
5550 Default behavior is to try 'X', then drop back to 'M' if the stub
5551 fails to respond. The settable variable `remotebinarydownload'
5552 allows explicit control over the use of 'X'.
5554 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5555 full 64-bit address. The command
5557 set remoteaddresssize 32
5559 can be used to revert to the old behaviour. For existing remote stubs
5560 the change should not be noticed, as the additional address information
5563 In order to assist in debugging stubs, you may use the maintenance
5564 command `packet' to send any text string to the stub. For instance,
5566 maint packet heythere
5568 sends the packet "$heythere#<checksum>". Note that it is very easy to
5569 disrupt a debugging session by sending the wrong packet at the wrong
5572 The compare-sections command allows you to compare section data on the
5573 target to what is in the executable file without uploading or
5574 downloading, by comparing CRC checksums.
5576 * Tracing can collect general expressions
5578 You may now collect general expressions at tracepoints. This requires
5579 further additions to the target-side stub; see tracepoint.c and
5580 doc/agentexpr.texi for further details.
5582 * mask-address variable for Mips
5584 For Mips targets, you may control the zeroing of the upper 32 bits of
5585 a 64-bit address by entering `set mask-address on'. This is mainly
5586 of interest to users of embedded R4xxx and R5xxx processors.
5588 * Higher serial baud rates
5590 GDB's serial code now allows you to specify baud rates 57600, 115200,
5591 230400, and 460800 baud. (Note that your host system may not be able
5592 to achieve all of these rates.)
5596 The i960 configuration now includes an initial implementation of a
5597 builtin simulator, contributed by Jim Wilson.
5600 *** Changes in GDB-4.17:
5602 * New native configurations
5604 Alpha GNU/Linux alpha*-*-linux*
5605 Unixware 2.x i[3456]86-unixware2*
5606 Irix 6.x mips*-sgi-irix6*
5607 PowerPC GNU/Linux powerpc-*-linux*
5608 PowerPC Solaris powerpcle-*-solaris*
5609 Sparc GNU/Linux sparc-*-linux*
5610 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5614 Argonaut Risc Chip (ARC) arc-*-*
5615 Hitachi H8/300S h8300*-*-*
5616 Matsushita MN10200 w/simulator mn10200-*-*
5617 Matsushita MN10300 w/simulator mn10300-*-*
5618 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5619 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5620 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5621 Mitsubishi D10V w/simulator d10v-*-*
5622 Mitsubishi M32R/D w/simulator m32r-*-elf*
5623 Tsqware Sparclet sparclet-*-*
5624 NEC V850 w/simulator v850-*-*
5626 * New debugging protocols
5628 ARM with RDI protocol arm*-*-*
5629 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5630 DDB and LSI variants of PMON protocol mips*-*-*
5631 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5632 PowerPC with SDS protocol powerpc{,le}-*-eabi
5633 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5637 All configurations can now understand and use the DWARF 2 debugging
5638 format. The choice is automatic, if the symbol file contains DWARF 2
5643 GDB now includes basic Java language support. This support is
5644 only useful with Java compilers that produce native machine code.
5646 * solib-absolute-prefix and solib-search-path
5648 For SunOS and SVR4 shared libraries, you may now set the prefix for
5649 loading absolute shared library symbol files, and the search path for
5650 locating non-absolute shared library symbol files.
5652 * Live range splitting
5654 GDB can now effectively debug code for which GCC has performed live
5655 range splitting as part of its optimization. See gdb/doc/LRS for
5656 more details on the expected format of the stabs information.
5660 GDB's support for the GNU Hurd, including thread debugging, has been
5661 updated to work with current versions of the Hurd.
5665 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5666 instruction set. ARM GDB automatically detects when Thumb
5667 instructions are in use, and adjusts disassembly and backtracing
5672 GDB's MIPS target configurations now handle the MIP16 16-bit
5677 GDB now includes support for overlays; if an executable has been
5678 linked such that multiple sections are based at the same address, GDB
5679 will decide which section to use for symbolic info. You can choose to
5680 control the decision manually, using overlay commands, or implement
5681 additional target-side support and use "overlay load-target" to bring
5682 in the overlay mapping. Do "help overlay" for more detail.
5686 The command "info symbol <address>" displays information about
5687 the symbol at the specified address.
5691 The standard remote protocol now includes an extension that allows
5692 asynchronous collection and display of trace data. This requires
5693 extensive support in the target-side debugging stub. Tracing mode
5694 includes a new interaction mode in GDB and new commands: see the
5695 file tracepoint.c for more details.
5699 Configurations for embedded MIPS now include a simulator contributed
5700 by Cygnus Solutions. The simulator supports the instruction sets
5701 of most MIPS variants.
5705 Sparc configurations may now include the ERC32 simulator contributed
5706 by the European Space Agency. The simulator is not built into
5707 Sparc targets by default; configure with --enable-sim to include it.
5711 For target configurations that may include multiple variants of a
5712 basic architecture (such as MIPS and SH), you may now set the
5713 architecture explicitly. "set arch" sets, "info arch" lists
5714 the possible architectures.
5716 *** Changes in GDB-4.16:
5718 * New native configurations
5720 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5721 M68K NetBSD m68k-*-netbsd*
5722 PowerPC AIX 4.x powerpc-*-aix*
5723 PowerPC MacOS powerpc-*-macos*
5724 PowerPC Windows NT powerpcle-*-cygwin32
5725 RS/6000 AIX 4.x rs6000-*-aix4*
5729 ARM with RDP protocol arm-*-*
5730 I960 with MON960 i960-*-coff
5731 MIPS VxWorks mips*-*-vxworks*
5732 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5733 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5735 Matra Sparclet sparclet-*-*
5739 The powerpc-eabi configuration now includes the PSIM simulator,
5740 contributed by Andrew Cagney, with assistance from Mike Meissner.
5741 PSIM is a very elaborate model of the PowerPC, including not only
5742 basic instruction set execution, but also details of execution unit
5743 performance and I/O hardware. See sim/ppc/README for more details.
5747 GDB now works with Solaris 2.5.
5749 * Windows 95/NT native
5751 GDB will now work as a native debugger on Windows 95 and Windows NT.
5752 To build it from source, you must use the "gnu-win32" environment,
5753 which uses a DLL to emulate enough of Unix to run the GNU tools.
5754 Further information, binaries, and sources are available at
5755 ftp.cygnus.com, under pub/gnu-win32.
5757 * dont-repeat command
5759 If a user-defined command includes the command `dont-repeat', then the
5760 command will not be repeated if the user just types return. This is
5761 useful if the command is time-consuming to run, so that accidental
5762 extra keystrokes don't run the same command many times.
5764 * Send break instead of ^C
5766 The standard remote protocol now includes an option to send a break
5767 rather than a ^C to the target in order to interrupt it. By default,
5768 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5770 * Remote protocol timeout
5772 The standard remote protocol includes a new variable `remotetimeout'
5773 that allows you to set the number of seconds before GDB gives up trying
5774 to read from the target. The default value is 2.
5776 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5778 By default GDB will automatically keep track of objects as they are
5779 loaded and unloaded by the dynamic linker. By using the command `set
5780 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5781 when shared library events occur, thus allowing you to set breakpoints
5782 in shared libraries which are explicitly loaded by the inferior.
5784 Note this feature does not work on hpux8. On hpux9 you must link
5785 /usr/lib/end.o into your program. This feature should work
5786 automatically on hpux10.
5788 * Irix 5.x hardware watchpoint support
5790 Irix 5 configurations now support the use of hardware watchpoints.
5792 * Mips protocol "SYN garbage limit"
5794 When debugging a Mips target using the `target mips' protocol, you
5795 may set the number of characters that GDB will ignore by setting
5796 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5797 every character. The default value is 1050.
5799 * Recording and replaying remote debug sessions
5801 If you set `remotelogfile' to the name of a file, gdb will write to it
5802 a recording of a remote debug session. This recording may then be
5803 replayed back to gdb using "gdbreplay". See gdbserver/README for
5804 details. This is useful when you have a problem with GDB while doing
5805 remote debugging; you can make a recording of the session and send it
5806 to someone else, who can then recreate the problem.
5808 * Speedups for remote debugging
5810 GDB includes speedups for downloading and stepping MIPS systems using
5811 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5812 and more efficient S-record downloading.
5814 * Memory use reductions and statistics collection
5816 GDB now uses less memory and reports statistics about memory usage.
5817 Try the `maint print statistics' command, for example.
5819 *** Changes in GDB-4.15:
5821 * Psymtabs for XCOFF
5823 The symbol reader for AIX GDB now uses partial symbol tables. This
5824 can greatly improve startup time, especially for large executables.
5826 * Remote targets use caching
5828 Remote targets now use a data cache to speed up communication with the
5829 remote side. The data cache could lead to incorrect results because
5830 it doesn't know about volatile variables, thus making it impossible to
5831 debug targets which use memory mapped I/O devices. `set remotecache
5832 off' turns the the data cache off.
5834 * Remote targets may have threads
5836 The standard remote protocol now includes support for multiple threads
5837 in the target system, using new protocol commands 'H' and 'T'. See
5838 gdb/remote.c for details.
5842 If GDB is configured with `--enable-netrom', then it will include
5843 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5844 acts as though it is a bank of ROM on the target board, but you can
5845 write into it over the network. GDB's support consists only of
5846 support for fast loading into the emulated ROM; to debug, you must use
5847 another protocol, such as standard remote protocol. The usual
5848 sequence is something like
5850 target nrom <netrom-hostname>
5852 target remote <netrom-hostname>:1235
5856 GDB now includes support for the Apple Macintosh, as a host only. It
5857 may be run as either an MPW tool or as a standalone application, and
5858 it can debug through the serial port. All the usual GDB commands are
5859 available, but to the target command, you must supply "serial" as the
5860 device type instead of "/dev/ttyXX". See mpw-README in the main
5861 directory for more information on how to build. The MPW configuration
5862 scripts */mpw-config.in support only a few targets, and only the
5863 mips-idt-ecoff target has been tested.
5867 GDB configuration now uses autoconf. This is not user-visible,
5868 but does simplify configuration and building.
5872 GDB now supports hpux10.
5874 *** Changes in GDB-4.14:
5876 * New native configurations
5878 x86 FreeBSD i[345]86-*-freebsd
5879 x86 NetBSD i[345]86-*-netbsd
5880 NS32k NetBSD ns32k-*-netbsd
5881 Sparc NetBSD sparc-*-netbsd
5885 A29K VxWorks a29k-*-vxworks
5886 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5887 CPU32 EST-300 emulator m68*-*-est*
5888 PowerPC ELF powerpc-*-elf
5891 * Alpha OSF/1 support for procfs
5893 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5894 possible to attach to running processes. As the mounting of the /proc
5895 filesystem is optional on the Alpha, GDB automatically determines
5896 the availability of /proc during startup. This can lead to problems
5897 if /proc is unmounted after GDB has been started.
5899 * Arguments to user-defined commands
5901 User commands may accept up to 10 arguments separated by whitespace.
5902 Arguments are accessed within the user command via $arg0..$arg9. A
5905 print $arg0 + $arg1 + $arg2
5907 To execute the command use:
5910 Defines the command "adder" which prints the sum of its three arguments.
5911 Note the arguments are text substitutions, so they may reference variables,
5912 use complex expressions, or even perform inferior function calls.
5914 * New `if' and `while' commands
5916 This makes it possible to write more sophisticated user-defined
5917 commands. Both commands take a single argument, which is the
5918 expression to evaluate, and must be followed by the commands to
5919 execute, one per line, if the expression is nonzero, the list being
5920 terminated by the word `end'. The `if' command list may include an
5921 `else' word, which causes the following commands to be executed only
5922 if the expression is zero.
5924 * Fortran source language mode
5926 GDB now includes partial support for Fortran 77. It will recognize
5927 Fortran programs and can evaluate a subset of Fortran expressions, but
5928 variables and functions may not be handled correctly. GDB will work
5929 with G77, but does not yet know much about symbols emitted by other
5932 * Better HPUX support
5934 Most debugging facilities now work on dynamic executables for HPPAs
5935 running hpux9 or later. You can attach to running dynamically linked
5936 processes, but by default the dynamic libraries will be read-only, so
5937 for instance you won't be able to put breakpoints in them. To change
5938 that behavior do the following before running the program:
5944 This will cause the libraries to be mapped private and read-write.
5945 To revert to the normal behavior, do this:
5951 You cannot set breakpoints or examine data in the library until after
5952 the library is loaded if the function/data symbols do not have
5955 GDB can now also read debug symbols produced by the HP C compiler on
5956 HPPAs (sorry, no C++, Fortran or 68k support).
5958 * Target byte order now dynamically selectable
5960 You can choose which byte order to use with a target system, via the
5961 commands "set endian big" and "set endian little", and you can see the
5962 current setting by using "show endian". You can also give the command
5963 "set endian auto", in which case GDB will use the byte order
5964 associated with the executable. Currently, only embedded MIPS
5965 configurations support dynamic selection of target byte order.
5967 * New DOS host serial code
5969 This version uses DPMI interrupts to handle buffered I/O, so you
5970 no longer need to run asynctsr when debugging boards connected to
5973 *** Changes in GDB-4.13:
5975 * New "complete" command
5977 This lists all the possible completions for the rest of the line, if it
5978 were to be given as a command itself. This is intended for use by emacs.
5980 * Trailing space optional in prompt
5982 "set prompt" no longer adds a space for you after the prompt you set. This
5983 allows you to set a prompt which ends in a space or one that does not.
5985 * Breakpoint hit counts
5987 "info break" now displays a count of the number of times the breakpoint
5988 has been hit. This is especially useful in conjunction with "ignore"; you
5989 can ignore a large number of breakpoint hits, look at the breakpoint info
5990 to see how many times the breakpoint was hit, then run again, ignoring one
5991 less than that number, and this will get you quickly to the last hit of
5994 * Ability to stop printing at NULL character
5996 "set print null-stop" will cause GDB to stop printing the characters of
5997 an array when the first NULL is encountered. This is useful when large
5998 arrays actually contain only short strings.
6000 * Shared library breakpoints
6002 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6003 breakpoints in shared libraries before the executable is run.
6005 * Hardware watchpoints
6007 There is a new hardware breakpoint for the watch command for sparclite
6008 targets. See gdb/sparclite/hw_breakpoint.note.
6010 Hardware watchpoints are also now supported under GNU/Linux.
6014 Annotations have been added. These are for use with graphical interfaces,
6015 and are still experimental. Currently only gdba.el uses these.
6017 * Improved Irix 5 support
6019 GDB now works properly with Irix 5.2.
6021 * Improved HPPA support
6023 GDB now works properly with the latest GCC and GAS.
6025 * New native configurations
6027 Sequent PTX4 i[34]86-sequent-ptx4
6028 HPPA running OSF/1 hppa*-*-osf*
6029 Atari TT running SVR4 m68*-*-sysv4*
6030 RS/6000 LynxOS rs6000-*-lynxos*
6034 OS/9000 i[34]86-*-os9k
6035 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6038 * Hitachi SH7000 and E7000-PC ICE support
6040 There is now support for communicating with the Hitachi E7000-PC ICE.
6041 This is available automatically when GDB is configured for the SH.
6045 As usual, a variety of small fixes and improvements, both generic
6046 and configuration-specific. See the ChangeLog for more detail.
6048 *** Changes in GDB-4.12:
6050 * Irix 5 is now supported
6054 GDB-4.12 on the HPPA has a number of changes which make it unable
6055 to debug the output from the currently released versions of GCC and
6056 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6057 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6058 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6061 *** Changes in GDB-4.11:
6063 * User visible changes:
6067 The "set remotedebug" option is now consistent between the mips remote
6068 target, remote targets using the gdb-specific protocol, UDI (AMD's
6069 debug protocol for the 29k) and the 88k bug monitor. It is now an
6070 integer specifying a debug level (normally 0 or 1, but 2 means more
6071 debugging info for the mips target).
6073 * DEC Alpha native support
6075 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6076 debug info, but GDB works fairly well with the DEC compiler and should
6077 work with a future GCC release. See the README file for a few
6078 Alpha-specific notes.
6080 * Preliminary thread implementation
6082 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6084 * LynxOS native and target support for 386
6086 This release has been hosted on LynxOS 2.2, and also can be configured
6087 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6090 * Improvements in C++ mangling/demangling.
6092 This release has much better g++ debugging, specifically in name
6093 mangling/demangling, virtual function calls, print virtual table,
6094 call methods, ...etc.
6096 *** Changes in GDB-4.10:
6098 * User visible changes:
6100 Remote debugging using the GDB-specific (`target remote') protocol now
6101 supports the `load' command. This is only useful if you have some
6102 other way of getting the stub to the target system, and you can put it
6103 somewhere in memory where it won't get clobbered by the download.
6105 Filename completion now works.
6107 When run under emacs mode, the "info line" command now causes the
6108 arrow to point to the line specified. Also, "info line" prints
6109 addresses in symbolic form (as well as hex).
6111 All vxworks based targets now support a user settable option, called
6112 vxworks-timeout. This option represents the number of seconds gdb
6113 should wait for responses to rpc's. You might want to use this if
6114 your vxworks target is, perhaps, a slow software simulator or happens
6115 to be on the far side of a thin network line.
6119 This release contains support for using a DEC alpha as a GDB host for
6120 cross debugging. Native alpha debugging is not supported yet.
6123 *** Changes in GDB-4.9:
6127 This is the first GDB release which is accompanied by a matching testsuite.
6128 The testsuite requires installation of dejagnu, which should be available
6129 via ftp from most sites that carry GNU software.
6133 'Cfront' style demangling has had its name changed to 'ARM' style, to
6134 emphasize that it was written from the specifications in the C++ Annotated
6135 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6136 disclaimers, it still generated too much confusion with users attempting to
6137 use gdb with AT&T cfront.
6141 GDB now uses a standard remote interface to a simulator library.
6142 So far, the library contains simulators for the Zilog Z8001/2, the
6143 Hitachi H8/300, H8/500 and Super-H.
6145 * New targets supported
6147 H8/300 simulator h8300-hitachi-hms or h8300hms
6148 H8/500 simulator h8500-hitachi-hms or h8500hms
6149 SH simulator sh-hitachi-hms or sh
6150 Z8000 simulator z8k-zilog-none or z8ksim
6151 IDT MIPS board over serial line mips-idt-ecoff
6153 Cross-debugging to GO32 targets is supported. It requires a custom
6154 version of the i386-stub.c module which is integrated with the
6155 GO32 memory extender.
6157 * New remote protocols
6159 MIPS remote debugging protocol.
6161 * New source languages supported
6163 This version includes preliminary support for Chill, a Pascal like language
6164 used by telecommunications companies. Chill support is also being integrated
6165 into the GNU compiler, but we don't know when it will be publically available.
6168 *** Changes in GDB-4.8:
6170 * HP Precision Architecture supported
6172 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6173 version of this support was available as a set of patches from the
6174 University of Utah. GDB does not support debugging of programs
6175 compiled with the HP compiler, because HP will not document their file
6176 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6177 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6179 Many problems in the preliminary version have been fixed.
6181 * Faster and better demangling
6183 We have improved template demangling and fixed numerous bugs in the GNU style
6184 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6185 character types (wchar_t) are now supported. Demangling of each symbol is now
6186 only done once, and is cached when the symbol table for a file is read in.
6187 This results in a small increase in memory usage for C programs, a moderate
6188 increase in memory usage for C++ programs, and a fantastic speedup in
6191 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6192 from the specifications in the Annotated Reference Manual, which AT&T's
6193 compiler does not actually implement.
6195 * G++ multiple inheritance compiler problem
6197 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6198 inheritance lattices was reworked to properly discover ambiguities. We
6199 recently found an example which causes this new algorithm to fail in a
6200 very subtle way, producing bad debug information for those classes.
6201 The file 'gcc.patch' (in this directory) can be applied to gcc to
6202 circumvent the problem. A future GCC release will contain a complete
6205 The previous G++ debug info problem (mentioned below for the gdb-4.7
6206 release) is fixed in gcc version 2.3.2.
6208 * Improved configure script
6210 The `configure' script will now attempt to guess your system type if
6211 you don't supply a host system type. The old scheme of supplying a
6212 host system triplet is preferable over using this. All the magic is
6213 done in the new `config.guess' script. Examine it for details.
6215 We have also brought our configure script much more in line with the FSF's
6216 version. It now supports the --with-xxx options. In particular,
6217 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6218 The resulting GDB will not be able to read arbitrary object file formats --
6219 only the format ``expected'' to be used on the configured target system.
6220 We hope to make this the default in a future release.
6222 * Documentation improvements
6224 There's new internal documentation on how to modify GDB, and how to
6225 produce clean changes to the code. We implore people to read it
6226 before submitting changes.
6228 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6229 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6230 `info' files are also provided. To build `info' files from scratch,
6231 you will need the latest `makeinfo' release, which will be available in
6232 a future texinfo-X.Y release.
6234 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6235 We're not sure exactly which versions have this problem, but it has
6236 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6237 or better. If that isn't possible, there is a patch in
6238 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6239 around this problem.
6243 GDB now supports array constants that can be used in expressions typed in by
6244 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6245 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6248 The new directory `gdb/sparclite' contains a program that demonstrates
6249 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6251 * New native hosts supported
6253 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6254 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6256 * New targets supported
6258 AMD 29k family via UDI a29k-amd-udi or udi29k
6260 * New file formats supported
6262 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6263 HPUX core files, and SCO 3.2v2 core files.
6267 Attaching to processes now works again; thanks for the many bug reports.
6269 We have also stomped on a bunch of core dumps caused by
6270 printf_filtered("%s") problems.
6272 We eliminated a copyright problem on the rpc and ptrace header files
6273 for VxWorks, which was discovered at the last minute during the 4.7
6274 release. You should now be able to build a VxWorks GDB.
6276 You can now interrupt gdb while an attached process is running. This
6277 will cause the attached process to stop, and give control back to GDB.
6279 We fixed problems caused by using too many file descriptors
6280 for reading symbols from object files and libraries. This was
6281 especially a problem for programs that used many (~100) shared
6284 The `step' command now only enters a subroutine if there is line number
6285 information for the subroutine. Otherwise it acts like the `next'
6286 command. Previously, `step' would enter subroutines if there was
6287 any debugging information about the routine. This avoids problems
6288 when using `cc -g1' on MIPS machines.
6290 * Internal improvements
6292 GDB's internal interfaces have been improved to make it easier to support
6293 debugging of multiple languages in the future.
6295 GDB now uses a common structure for symbol information internally.
6296 Minimal symbols (derived from linkage symbols in object files), partial
6297 symbols (from a quick scan of debug information), and full symbols
6298 contain a common subset of information, making it easier to write
6299 shared code that handles any of them.
6301 * New command line options
6303 We now accept --silent as an alias for --quiet.
6307 The memory-mapped-malloc library is now licensed under the GNU Library
6308 General Public License.
6310 *** Changes in GDB-4.7:
6312 * Host/native/target split
6314 GDB has had some major internal surgery to untangle the support for
6315 hosts and remote targets. Now, when you configure GDB for a remote
6316 target, it will no longer load in all of the support for debugging
6317 local programs on the host. When fully completed and tested, this will
6318 ensure that arbitrary host/target combinations are possible.
6320 The primary conceptual shift is to separate the non-portable code in
6321 GDB into three categories. Host specific code is required any time GDB
6322 is compiled on that host, regardless of the target. Target specific
6323 code relates to the peculiarities of the target, but can be compiled on
6324 any host. Native specific code is everything else: it can only be
6325 built when the host and target are the same system. Child process
6326 handling and core file support are two common `native' examples.
6328 GDB's use of /proc for controlling Unix child processes is now cleaner.
6329 It has been split out into a single module under the `target_ops' vector,
6330 plus two native-dependent functions for each system that uses /proc.
6332 * New hosts supported
6334 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6335 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6336 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6338 * New targets supported
6340 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6341 68030 and CPU32 m68030-*-*, m68332-*-*
6343 * New native hosts supported
6345 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6346 (386bsd is not well tested yet)
6347 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6349 * New file formats supported
6351 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6352 supports reading of `a.out.adobe' object files, which are an a.out
6353 format extended with minimal information about multiple sections.
6357 `show copying' is the same as the old `info copying'.
6358 `show warranty' is the same as `info warrantee'.
6359 These were renamed for consistency. The old commands continue to work.
6361 `info handle' is a new alias for `info signals'.
6363 You can now define pre-command hooks, which attach arbitrary command
6364 scripts to any command. The commands in the hook will be executed
6365 prior to the user's command. You can also create a hook which will be
6366 executed whenever the program stops. See gdb.texinfo.
6370 We now deal with Cfront style name mangling, and can even extract type
6371 info from mangled symbols. GDB can automatically figure out which
6372 symbol mangling style your C++ compiler uses.
6374 Calling of methods and virtual functions has been improved as well.
6378 The crash that occured when debugging Sun Ansi-C compiled binaries is
6379 fixed. This was due to mishandling of the extra N_SO stabs output
6382 We also finally got Ultrix 4.2 running in house, and fixed core file
6383 support, with help from a dozen people on the net.
6385 John M. Farrell discovered that the reason that single-stepping was so
6386 slow on all of the Mips based platforms (primarily SGI and DEC) was
6387 that we were trying to demangle and lookup a symbol used for internal
6388 purposes on every instruction that was being stepped through. Changing
6389 the name of that symbol so that it couldn't be mistaken for a C++
6390 mangled symbol sped things up a great deal.
6392 Rich Pixley sped up symbol lookups in general by getting much smarter
6393 about when C++ symbol mangling is necessary. This should make symbol
6394 completion (TAB on the command line) much faster. It's not as fast as
6395 we'd like, but it's significantly faster than gdb-4.6.
6399 A new user controllable variable 'call_scratch_address' can
6400 specify the location of a scratch area to be used when GDB
6401 calls a function in the target. This is necessary because the
6402 usual method of putting the scratch area on the stack does not work
6403 in systems that have separate instruction and data spaces.
6405 We integrated changes to support the 29k UDI (Universal Debugger
6406 Interface), but discovered at the last minute that we didn't have all
6407 of the appropriate copyright paperwork. We are working with AMD to
6408 resolve this, and hope to have it available soon.
6412 We have sped up the remote serial line protocol, especially for targets
6413 with lots of registers. It now supports a new `expedited status' ('T')
6414 message which can be used in place of the existing 'S' status message.
6415 This allows the remote stub to send only the registers that GDB
6416 needs to make a quick decision about single-stepping or conditional
6417 breakpoints, eliminating the need to fetch the entire register set for
6418 each instruction being stepped through.
6420 The GDB remote serial protocol now implements a write-through cache for
6421 registers, only re-reading the registers if the target has run.
6423 There is also a new remote serial stub for SPARC processors. You can
6424 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6425 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6426 processor with a serial port.
6430 Configure.in files have become much easier to read and modify. A new
6431 `table driven' format makes it more obvious what configurations are
6432 supported, and what files each one uses.
6436 There is a new opcodes library which will eventually contain all of the
6437 disassembly routines and opcode tables. At present, it only contains
6438 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6439 disassembler (binutils/objdump) to share these routines.
6441 The libiberty library is now copylefted under the GNU Library General
6442 Public License. This allows more liberal use, and was done so libg++
6443 can use it. This makes no difference to GDB, since the Library License
6444 grants all the rights from the General Public License.
6448 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6449 reference to the stabs symbol info used by the debugger. It is (as far
6450 as we know) the only published document on this fascinating topic. We
6451 encourage you to read it, compare it to the stabs information on your
6452 system, and send improvements on the document in general (to
6453 bug-gdb@prep.ai.mit.edu).
6455 And, of course, many bugs have been fixed.
6458 *** Changes in GDB-4.6:
6460 * Better support for C++ function names
6462 GDB now accepts as input the "demangled form" of C++ overloaded function
6463 names and member function names, and can do command completion on such names
6464 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6465 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6466 Make use of command completion, it is your friend.
6468 GDB also now accepts a variety of C++ mangled symbol formats. They are
6469 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6470 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6471 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6472 for the list of formats.
6474 * G++ symbol mangling problem
6476 Recent versions of gcc have a bug in how they emit debugging information for
6477 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6478 directory) can be applied to gcc to fix the problem. Alternatively, if you
6479 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6480 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6481 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6484 * New 'maintenance' command
6486 All of the commands related to hacking GDB internals have been moved out of
6487 the main command set, and now live behind the 'maintenance' command. This
6488 can also be abbreviated as 'mt'. The following changes were made:
6490 dump-me -> maintenance dump-me
6491 info all-breakpoints -> maintenance info breakpoints
6492 printmsyms -> maintenance print msyms
6493 printobjfiles -> maintenance print objfiles
6494 printpsyms -> maintenance print psymbols
6495 printsyms -> maintenance print symbols
6497 The following commands are new:
6499 maintenance demangle Call internal GDB demangler routine to
6500 demangle a C++ link name and prints the result.
6501 maintenance print type Print a type chain for a given symbol
6503 * Change to .gdbinit file processing
6505 We now read the $HOME/.gdbinit file before processing the argv arguments
6506 (e.g. reading symbol files or core files). This allows global parameters to
6507 be set, which will apply during the symbol reading. The ./.gdbinit is still
6508 read after argv processing.
6510 * New hosts supported
6512 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6514 GNU/Linux support i386-unknown-linux or linux
6516 We are also including code to support the HP/PA running BSD and HPUX. This
6517 is almost guaranteed not to work, as we didn't have time to test or build it
6518 for this release. We are including it so that the more adventurous (or
6519 masochistic) of you can play with it. We also had major problems with the
6520 fact that the compiler that we got from HP doesn't support the -g option.
6523 * New targets supported
6525 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6527 * More smarts about finding #include files
6529 GDB now remembers the compilation directory for all include files, and for
6530 all files from which C is generated (like yacc and lex sources). This
6531 greatly improves GDB's ability to find yacc/lex sources, and include files,
6532 especially if you are debugging your program from a directory different from
6533 the one that contains your sources.
6535 We also fixed a bug which caused difficulty with listing and setting
6536 breakpoints in include files which contain C code. (In the past, you had to
6537 try twice in order to list an include file that you hadn't looked at before.)
6539 * Interesting infernals change
6541 GDB now deals with arbitrary numbers of sections, where the symbols for each
6542 section must be relocated relative to that section's landing place in the
6543 target's address space. This work was needed to support ELF with embedded
6544 stabs used by Solaris-2.0.
6546 * Bug fixes (of course!)
6548 There have been loads of fixes for the following things:
6549 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6550 i960, stabs, DOS(GO32), procfs, etc...
6552 See the ChangeLog for details.
6554 *** Changes in GDB-4.5:
6556 * New machines supported (host and target)
6558 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6560 SGI Irix-4.x mips-sgi-irix4 or iris4
6562 * New malloc package
6564 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6565 Mmalloc is capable of handling mutiple heaps of memory. It is also
6566 capable of saving a heap to a file, and then mapping it back in later.
6567 This can be used to greatly speedup the startup of GDB by using a
6568 pre-parsed symbol table which lives in a mmalloc managed heap. For
6569 more details, please read mmalloc/mmalloc.texi.
6573 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6574 'help info proc' for details.
6576 * MIPS ecoff symbol table format
6578 The code that reads MIPS symbol table format is now supported on all hosts.
6579 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6582 * File name changes for MS-DOS
6584 Many files in the config directories have been renamed to make it easier to
6585 support GDB on MS-DOSe systems (which have very restrictive file name
6586 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6587 environment) is close to working but has some remaining problems. Note
6588 that debugging of DOS programs is not supported, due to limitations
6589 in the ``operating system'', but it can be used to host cross-debugging.
6591 * Cross byte order fixes
6593 Many fixes have been made to support cross debugging of Sparc and MIPS
6594 targets from hosts whose byte order differs.
6596 * New -mapped and -readnow options
6598 If memory-mapped files are available on your system through the 'mmap'
6599 system call, you can use the -mapped option on the `file' or
6600 `symbol-file' commands to cause GDB to write the symbols from your
6601 program into a reusable file. If the program you are debugging is
6602 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6603 Future GDB debugging sessions will notice the presence of this file,
6604 and will quickly map in symbol information from it, rather than reading
6605 the symbol table from the executable program. Using the '-mapped'
6606 option in a GDB `file' or `symbol-file' command has the same effect as
6607 starting GDB with the '-mapped' command-line option.
6609 You can cause GDB to read the entire symbol table immediately by using
6610 the '-readnow' option with any of the commands that load symbol table
6611 information (or on the GDB command line). This makes the command
6612 slower, but makes future operations faster.
6614 The -mapped and -readnow options are typically combined in order to
6615 build a `fred.syms' file that contains complete symbol information.
6616 A simple GDB invocation to do nothing but build a `.syms' file for future
6619 gdb -batch -nx -mapped -readnow programname
6621 The `.syms' file is specific to the host machine on which GDB is run.
6622 It holds an exact image of GDB's internal symbol table. It cannot be
6623 shared across multiple host platforms.
6625 * longjmp() handling
6627 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6628 siglongjmp() without losing control. This feature has not yet been ported to
6629 all systems. It currently works on many 386 platforms, all MIPS-based
6630 platforms (SGI, DECstation, etc), and Sun3/4.
6634 Preliminary work has been put in to support the new Solaris OS from Sun. At
6635 this time, it can control and debug processes, but it is not capable of
6640 As always, many many bug fixes. The major areas were with g++, and mipsread.
6641 People using the MIPS-based platforms should experience fewer mysterious
6642 crashes and trashed symbol tables.
6644 *** Changes in GDB-4.4:
6646 * New machines supported (host and target)
6648 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6650 BSD Reno on Vax vax-dec-bsd
6651 Ultrix on Vax vax-dec-ultrix
6653 * New machines supported (target)
6655 AMD 29000 embedded, using EBMON a29k-none-none
6659 GDB continues to improve its handling of C++. `References' work better.
6660 The demangler has also been improved, and now deals with symbols mangled as
6661 per the Annotated C++ Reference Guide.
6663 GDB also now handles `stabs' symbol information embedded in MIPS
6664 `ecoff' symbol tables. Since the ecoff format was not easily
6665 extensible to handle new languages such as C++, this appeared to be a
6666 good way to put C++ debugging info into MIPS binaries. This option
6667 will be supported in the GNU C compiler, version 2, when it is
6670 * New features for SVR4
6672 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6673 shared libraries. Debugging dynamically linked programs should present
6674 only minor differences from debugging statically linked programs.
6676 The `info proc' command will print out information about any process
6677 on an SVR4 system (including the one you are debugging). At the moment,
6678 it prints the address mappings of the process.
6680 If you bring up GDB on another SVR4 system, please send mail to
6681 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6683 * Better dynamic linking support in SunOS
6685 Reading symbols from shared libraries which contain debugging symbols
6686 now works properly. However, there remain issues such as automatic
6687 skipping of `transfer vector' code during function calls, which
6688 make it harder to debug code in a shared library, than to debug the
6689 same code linked statically.
6693 GDB is now using the latest `getopt' routines from the FSF. This
6694 version accepts the -- prefix for options with long names. GDB will
6695 continue to accept the old forms (-option and +option) as well.
6696 Various single letter abbreviations for options have been explicity
6697 added to the option table so that they won't get overshadowed in the
6698 future by other options that begin with the same letter.
6702 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6703 Many assorted bugs have been handled. Many more remain to be handled.
6704 See the various ChangeLog files (primarily in gdb and bfd) for details.
6707 *** Changes in GDB-4.3:
6709 * New machines supported (host and target)
6711 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6712 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6713 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6715 * Almost SCO Unix support
6717 We had hoped to support:
6718 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6719 (except for core file support), but we discovered very late in the release
6720 that it has problems with process groups that render gdb unusable. Sorry
6721 about that. I encourage people to fix it and post the fixes.
6723 * Preliminary ELF and DWARF support
6725 GDB can read ELF object files on System V Release 4, and can handle
6726 debugging records for C, in DWARF format, in ELF files. This support
6727 is preliminary. If you bring up GDB on another SVR4 system, please
6728 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6733 GDB now uses the latest `readline' library. One user-visible change
6734 is that two tabs will list possible command completions, which previously
6735 required typing M-? (meta-question mark, or ESC ?).
6739 The `stepi' bug that many of you noticed has been squashed.
6740 Many bugs in C++ have been handled. Many more remain to be handled.
6741 See the various ChangeLog files (primarily in gdb and bfd) for details.
6743 * State of the MIPS world (in case you wondered):
6745 GDB can understand the symbol tables emitted by the compilers
6746 supplied by most vendors of MIPS-based machines, including DEC. These
6747 symbol tables are in a format that essentially nobody else uses.
6749 Some versions of gcc come with an assembler post-processor called
6750 mips-tfile. This program is required if you want to do source-level
6751 debugging of gcc-compiled programs. I believe FSF does not ship
6752 mips-tfile with gcc version 1, but it will eventually come with gcc
6755 Debugging of g++ output remains a problem. g++ version 1.xx does not
6756 really support it at all. (If you're lucky, you should be able to get
6757 line numbers and stack traces to work, but no parameters or local
6758 variables.) With some work it should be possible to improve the
6761 When gcc version 2 is released, you will have somewhat better luck.
6762 However, even then you will get confusing results for inheritance and
6765 We will eventually provide full debugging of g++ output on
6766 DECstations. This will probably involve some kind of stabs-in-ecoff
6767 encapulation, but the details have not been worked out yet.
6770 *** Changes in GDB-4.2:
6772 * Improved configuration
6774 Only one copy of `configure' exists now, and it is not self-modifying.
6775 Porting BFD is simpler.
6779 The `step' and `next' commands now only stop at the first instruction
6780 of a source line. This prevents the multiple stops that used to occur
6781 in switch statements, for-loops, etc. `Step' continues to stop if a
6782 function that has debugging information is called within the line.
6786 Lots of small bugs fixed. More remain.
6788 * New host supported (not target)
6790 Intel 386 PC clone running Mach i386-none-mach
6793 *** Changes in GDB-4.1:
6795 * Multiple source language support
6797 GDB now has internal scaffolding to handle several source languages.
6798 It determines the type of each source file from its filename extension,
6799 and will switch expression parsing and number formatting to match the
6800 language of the function in the currently selected stack frame.
6801 You can also specifically set the language to be used, with
6802 `set language c' or `set language modula-2'.
6806 GDB now has preliminary support for the GNU Modula-2 compiler,
6807 currently under development at the State University of New York at
6808 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6809 continue through the fall of 1991 and into 1992.
6811 Other Modula-2 compilers are currently not supported, and attempting to
6812 debug programs compiled with them will likely result in an error as the
6813 symbol table is read. Feel free to work on it, though!
6815 There are hooks in GDB for strict type checking and range checking,
6816 in the `Modula-2 philosophy', but they do not currently work.
6820 GDB can now write to executable and core files (e.g. patch
6821 a variable's value). You must turn this switch on, specify
6822 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6823 by assigning a new value to a variable. Modifications take
6826 * Automatic SunOS shared library reading
6828 When you run your program, GDB automatically determines where its
6829 shared libraries (if any) have been loaded, and reads their symbols.
6830 The `share' command is no longer needed. This also works when
6831 examining core files.
6835 You can specify the number of lines that the `list' command shows.
6838 * New machines supported (host and target)
6840 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6841 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6842 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6844 * New hosts supported (not targets)
6846 IBM RT/PC: romp-ibm-aix or rtpc
6848 * New targets supported (not hosts)
6850 AMD 29000 embedded with COFF a29k-none-coff
6851 AMD 29000 embedded with a.out a29k-none-aout
6852 Ultracomputer remote kernel debug a29k-nyu-kern
6854 * New remote interfaces
6860 *** Changes in GDB-4.0:
6864 Wide output is wrapped at good places to make the output more readable.
6866 Gdb now supports cross-debugging from a host machine of one type to a
6867 target machine of another type. Communication with the target system
6868 is over serial lines. The ``target'' command handles connecting to the
6869 remote system; the ``load'' command will download a program into the
6870 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6871 also supports debugging of realtime processes running under VxWorks,
6872 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6873 stub on the target system.
6875 New CPUs supported include the AMD 29000 and Intel 960.
6877 GDB now reads object files and symbol tables via a ``binary file''
6878 library, which allows a single copy of GDB to debug programs of multiple
6879 object file types such as a.out and coff.
6881 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6882 refcard.dvi and refcard.ps are available to format it).
6885 * Control-Variable user interface simplified
6887 All variables that control the operation of the debugger can be set
6888 by the ``set'' command, and displayed by the ``show'' command.
6890 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6891 ``Show prompt'' produces the response:
6892 Gdb's prompt is new-gdb=>.
6894 What follows are the NEW set commands. The command ``help set'' will
6895 print a complete list of old and new set commands. ``help set FOO''
6896 will give a longer description of the variable FOO. ``show'' will show
6897 all of the variable descriptions and their current settings.
6899 confirm on/off: Enables warning questions for operations that are
6900 hard to recover from, e.g. rerunning the program while
6901 it is already running. Default is ON.
6903 editing on/off: Enables EMACS style command line editing
6904 of input. Previous lines can be recalled with
6905 control-P, the current line can be edited with control-B,
6906 you can search for commands with control-R, etc.
6909 history filename NAME: NAME is where the gdb command history
6910 will be stored. The default is .gdb_history,
6911 or the value of the environment variable
6914 history size N: The size, in commands, of the command history. The
6915 default is 256, or the value of the environment variable
6918 history save on/off: If this value is set to ON, the history file will
6919 be saved after exiting gdb. If set to OFF, the
6920 file will not be saved. The default is OFF.
6922 history expansion on/off: If this value is set to ON, then csh-like
6923 history expansion will be performed on
6924 command line input. The default is OFF.
6926 radix N: Sets the default radix for input and output. It can be set
6927 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6928 in the current radix, so "set radix 10" is always a no-op.
6930 height N: This integer value is the number of lines on a page. Default
6931 is 24, the current `stty rows'' setting, or the ``li#''
6932 setting from the termcap entry matching the environment
6935 width N: This integer value is the number of characters on a line.
6936 Default is 80, the current `stty cols'' setting, or the ``co#''
6937 setting from the termcap entry matching the environment
6940 Note: ``set screensize'' is obsolete. Use ``set height'' and
6941 ``set width'' instead.
6943 print address on/off: Print memory addresses in various command displays,
6944 such as stack traces and structure values. Gdb looks
6945 more ``symbolic'' if you turn this off; it looks more
6946 ``machine level'' with it on. Default is ON.
6948 print array on/off: Prettyprint arrays. New convenient format! Default
6951 print demangle on/off: Print C++ symbols in "source" form if on,
6954 print asm-demangle on/off: Same, for assembler level printouts
6957 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6960 * Support for Epoch Environment.
6962 The epoch environment is a version of Emacs v18 with windowing. One
6963 new command, ``inspect'', is identical to ``print'', except that if you
6964 are running in the epoch environment, the value is printed in its own
6968 * Support for Shared Libraries
6970 GDB can now debug programs and core files that use SunOS shared libraries.
6971 Symbols from a shared library cannot be referenced
6972 before the shared library has been linked with the program (this
6973 happens after you type ``run'' and before the function main() is entered).
6974 At any time after this linking (including when examining core files
6975 from dynamically linked programs), gdb reads the symbols from each
6976 shared library when you type the ``sharedlibrary'' command.
6977 It can be abbreviated ``share''.
6979 sharedlibrary REGEXP: Load shared object library symbols for files
6980 matching a unix regular expression. No argument
6981 indicates to load symbols for all shared libraries.
6983 info sharedlibrary: Status of loaded shared libraries.
6988 A watchpoint stops execution of a program whenever the value of an
6989 expression changes. Checking for this slows down execution
6990 tremendously whenever you are in the scope of the expression, but is
6991 quite useful for catching tough ``bit-spreader'' or pointer misuse
6992 problems. Some machines such as the 386 have hardware for doing this
6993 more quickly, and future versions of gdb will use this hardware.
6995 watch EXP: Set a watchpoint (breakpoint) for an expression.
6997 info watchpoints: Information about your watchpoints.
6999 delete N: Deletes watchpoint number N (same as breakpoints).
7000 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7001 enable N: Re-enables watchpoint number N (same as breakpoints).
7004 * C++ multiple inheritance
7006 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7009 * C++ exception handling
7011 Gdb now supports limited C++ exception handling. Besides the existing
7012 ability to breakpoint on an exception handler, gdb can breakpoint on
7013 the raising of an exception (before the stack is peeled back to the
7016 catch FOO: If there is a FOO exception handler in the dynamic scope,
7017 set a breakpoint to catch exceptions which may be raised there.
7018 Multiple exceptions (``catch foo bar baz'') may be caught.
7020 info catch: Lists all exceptions which may be caught in the
7021 current stack frame.
7024 * Minor command changes
7026 The command ``call func (arg, arg, ...)'' now acts like the print
7027 command, except it does not print or save a value if the function's result
7028 is void. This is similar to dbx usage.
7030 The ``up'' and ``down'' commands now always print the frame they end up
7031 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7032 frames without printing.
7034 * New directory command
7036 'dir' now adds directories to the FRONT of the source search path.
7037 The path starts off empty. Source files that contain debug information
7038 about the directory in which they were compiled can be found even
7039 with an empty path; Sun CC and GCC include this information. If GDB can't
7040 find your source file in the current directory, type "dir .".
7042 * Configuring GDB for compilation
7044 For normal use, type ``./configure host''. See README or gdb.texinfo
7047 GDB now handles cross debugging. If you are remotely debugging between
7048 two different machines, type ``./configure host -target=targ''.
7049 Host is the machine where GDB will run; targ is the machine
7050 where the program that you are debugging will run.