1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
7 can be passed using the '[ADDRESS]:PORT' notation, or the regular
12 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
13 Apply a command to some frames.
14 FLAG arguments allow to control what output to produce and how to handle
15 errors raised when applying COMMAND to a frame.
18 Apply a command to all threads (ignoring errors and empty output).
19 Shortcut for 'thread apply all -s COMMAND'.
22 Apply a command to all frames (ignoring errors and empty output).
23 Shortcut for 'frame apply all -s COMMAND'.
26 Apply a command to all frames of all threads (ignoring errors and empty
28 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
32 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
33 The 'thread apply' command accepts new FLAG arguments.
34 FLAG arguments allow to control what output to produce and how to handle
35 errors raised when applying COMMAND to a thread.
37 *** Changes in GDB 8.2
39 * The 'set disassembler-options' command now supports specifying options
42 * The 'symbol-file' command now accepts an '-o' option to add a relative
43 offset to all sections.
45 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
46 a relative offset to all sections, but it allows to override the load
47 address of individual sections using '-s'.
49 * The 'add-symbol-file' command no longer requires the second argument
50 (address of the text section).
52 * The endianness used with the 'set endian auto' mode in the absence of
53 an executable selected for debugging is now the last endianness chosen
54 either by one of the 'set endian big' and 'set endian little' commands
55 or by inferring from the last executable used, rather than the startup
58 * The pager now allows a "c" response, meaning to disable the pager
59 for the rest of the current command.
61 * The commands 'info variables/functions/types' now show the source line
62 numbers of symbol definitions when available.
64 * 'info proc' now works on running processes on FreeBSD systems and core
65 files created on FreeBSD systems.
67 * C expressions can now use _Alignof, and C++ expressions can now use
74 Control display of debugging info regarding the FreeBSD native target.
76 set|show varsize-limit
77 This new setting allows the user to control the maximum size of Ada
78 objects being printed when those objects have a variable type,
79 instead of that maximum size being hardcoded to 65536 bytes.
81 set|show record btrace cpu
82 Controls the processor to be used for enabling errata workarounds for
85 maint check libthread-db
86 Run integrity checks on the current inferior's thread debugging
89 maint set check-libthread-db (on|off)
90 maint show check-libthread-db
91 Control whether to run integrity checks on inferior specific thread
92 debugging libraries as they are loaded. The default is not to
97 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
99 ** The commands attached to a breakpoint can be set by assigning to
100 the breakpoint's "commands" field.
102 ** gdb.execute can now execute multi-line gdb commands.
104 ** The new functions gdb.convenience_variable and
105 gdb.set_convenience_variable can be used to get and set the value
106 of convenience variables.
108 ** A gdb.Parameter will no longer print the "set" help text on an
109 ordinary "set"; instead by default a "set" will be silent unless
110 the get_set_string method returns a non-empty string.
114 RiscV ELF riscv*-*-elf
116 * Removed targets and native configurations
118 m88k running OpenBSD m88*-*-openbsd*
119 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
120 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
121 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
123 * Aarch64/Linux hardware watchpoints improvements
125 Hardware watchpoints on unaligned addresses are now properly
126 supported when running Linux kernel 4.10 or higher: read and access
127 watchpoints are no longer spuriously missed, and all watchpoints
128 lengths between 1 and 8 bytes are supported. On older kernels,
129 watchpoints set on unaligned addresses are no longer missed, with
130 the tradeoff that there is a possibility of false hits being
135 --enable-codesign=CERT
136 This can be used to invoke "codesign -s CERT" after building gdb.
137 This option is useful on macOS, where code signing is required for
138 gdb to work properly.
140 --disable-gdbcli has been removed
141 This is now silently accepted, but does nothing.
143 *** Changes in GDB 8.1
145 * GDB now supports dynamically creating arbitrary register groups specified
146 in XML target descriptions. This allows for finer grain grouping of
147 registers on systems with a large amount of registers.
149 * The 'ptype' command now accepts a '/o' flag, which prints the
150 offsets and sizes of fields in a struct, like the pahole(1) tool.
152 * New "--readnever" command line option instructs GDB to not read each
153 symbol file's symbolic debug information. This makes startup faster
154 but at the expense of not being able to perform symbolic debugging.
155 This option is intended for use cases where symbolic debugging will
156 not be used, e.g., when you only need to dump the debuggee's core.
158 * GDB now uses the GNU MPFR library, if available, to emulate target
159 floating-point arithmetic during expression evaluation when the target
160 uses different floating-point formats than the host. At least version
161 3.1 of GNU MPFR is required.
163 * GDB now supports access to the guarded-storage-control registers and the
164 software-based guarded-storage broadcast control registers on IBM z14.
166 * On Unix systems, GDB now supports transmitting environment variables
167 that are to be set or unset to GDBserver. These variables will
168 affect the environment to be passed to the remote inferior.
170 To inform GDB of environment variables that are to be transmitted to
171 GDBserver, use the "set environment" command. Only user set
172 environment variables are sent to GDBserver.
174 To inform GDB of environment variables that are to be unset before
175 the remote inferior is started by the GDBserver, use the "unset
176 environment" command.
178 * Completion improvements
180 ** GDB can now complete function parameters in linespecs and
181 explicit locations without quoting. When setting breakpoints,
182 quoting around functions names to help with TAB-completion is
183 generally no longer necessary. For example, this now completes
186 (gdb) b function(in[TAB]
187 (gdb) b function(int)
189 Related, GDB is no longer confused with completing functions in
190 C++ anonymous namespaces:
193 (gdb) b (anonymous namespace)::[TAB][TAB]
194 (anonymous namespace)::a_function()
195 (anonymous namespace)::b_function()
197 ** GDB now has much improved linespec and explicit locations TAB
198 completion support, that better understands what you're
199 completing and offers better suggestions. For example, GDB no
200 longer offers data symbols as possible completions when you're
201 setting a breakpoint.
203 ** GDB now TAB-completes label symbol names.
205 ** The "complete" command now mimics TAB completion accurately.
207 * New command line options (gcore)
210 Dump all memory mappings.
212 * Breakpoints on C++ functions are now set on all scopes by default
214 By default, breakpoints on functions/methods are now interpreted as
215 specifying all functions with the given name ignoring missing
216 leading scopes (namespaces and classes).
218 For example, assuming a C++ program with symbols named:
223 both commands "break func()" and "break B::func()" set a breakpoint
226 You can use the new flag "-qualified" to override this. This makes
227 GDB interpret the specified function name as a complete
228 fully-qualified name instead. For example, using the same C++
229 program, the "break -q B::func" command sets a breakpoint on
230 "B::func", only. A parameter has been added to the Python
231 gdb.Breakpoint constructor to achieve the same result when creating
232 a breakpoint from Python.
234 * Breakpoints on functions marked with C++ ABI tags
236 GDB can now set breakpoints on functions marked with C++ ABI tags
237 (e.g., [abi:cxx11]). See here for a description of ABI tags:
238 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
240 Functions with a C++11 abi tag are demangled/displayed like this:
242 function[abi:cxx11](int)
245 You can now set a breakpoint on such functions simply as if they had
248 (gdb) b function(int)
250 Or if you need to disambiguate between tags, like:
252 (gdb) b function[abi:other_tag](int)
254 Tab completion was adjusted accordingly as well.
258 ** New events gdb.new_inferior, gdb.inferior_deleted, and
259 gdb.new_thread are emitted. See the manual for further
260 description of these.
262 ** A new function, "gdb.rbreak" has been added to the Python API.
263 This function allows the setting of a large number of breakpoints
264 via a regex pattern in Python. See the manual for further details.
266 ** Python breakpoints can now accept explicit locations. See the
267 manual for a further description of this feature.
270 * New features in the GDB remote stub, GDBserver
272 ** GDBserver is now able to start inferior processes with a
273 specified initial working directory.
275 The user can set the desired working directory to be used from
276 GDB using the new "set cwd" command.
278 ** New "--selftest" command line option runs some GDBserver self
279 tests. These self tests are disabled in releases.
281 ** On Unix systems, GDBserver now does globbing expansion and variable
282 substitution in inferior command line arguments.
284 This is done by starting inferiors using a shell, like GDB does.
285 See "set startup-with-shell" in the user manual for how to disable
286 this from GDB when using "target extended-remote". When using
287 "target remote", you can disable the startup with shell by using the
288 new "--no-startup-with-shell" GDBserver command line option.
290 ** On Unix systems, GDBserver now supports receiving environment
291 variables that are to be set or unset from GDB. These variables
292 will affect the environment to be passed to the inferior.
294 * When catching an Ada exception raised with a message, GDB now prints
295 the message in the catchpoint hit notification. In GDB/MI mode, that
296 information is provided as an extra field named "exception-message"
297 in the *stopped notification.
299 * Trait objects can now be inspected When debugging Rust code. This
300 requires compiler support which will appear in Rust 1.24.
304 QEnvironmentHexEncoded
305 Inform GDBserver of an environment variable that is to be passed to
306 the inferior when starting it.
309 Inform GDBserver of an environment variable that is to be unset
310 before starting the remote inferior.
313 Inform GDBserver that the environment should be reset (i.e.,
314 user-set environment variables should be unset).
317 Indicates whether the inferior must be started with a shell or not.
320 Tell GDBserver that the inferior to be started should use a specific
323 * The "maintenance print c-tdesc" command now takes an optional
324 argument which is the file name of XML target description.
326 * The "maintenance selftest" command now takes an optional argument to
327 filter the tests to be run.
329 * The "enable", and "disable" commands now accept a range of
330 breakpoint locations, e.g. "enable 1.3-5".
335 Set and show the current working directory for the inferior.
338 Set and show compilation command used for compiling and injecting code
339 with the 'compile' commands.
341 set debug separate-debug-file
342 show debug separate-debug-file
343 Control the display of debug output about separate debug file search.
345 set dump-excluded-mappings
346 show dump-excluded-mappings
347 Control whether mappings marked with the VM_DONTDUMP flag should be
348 dumped when generating a core file.
351 List the registered selftests.
354 Start the debugged program stopping at the first instruction.
357 Control display of debugging messages related to OpenRISC targets.
359 set|show print type nested-type-limit
360 Set and show the limit of nesting level for nested types that the
361 type printer will show.
363 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
366 * Safer/improved support for debugging with no debug info
368 GDB no longer assumes functions with no debug information return
371 This means that GDB now refuses to call such functions unless you
372 tell it the function's type, by either casting the call to the
373 declared return type, or by casting the function to a function
374 pointer of the right type, and calling that:
376 (gdb) p getenv ("PATH")
377 'getenv' has unknown return type; cast the call to its declared return type
378 (gdb) p (char *) getenv ("PATH")
379 $1 = 0x7fffffffe "/usr/local/bin:/"...
380 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
381 $2 = 0x7fffffffe "/usr/local/bin:/"...
383 Similarly, GDB no longer assumes that global variables with no debug
384 info have type 'int', and refuses to print the variable's value
385 unless you tell it the variable's type:
388 'var' has unknown type; cast it to its declared type
392 * New native configurations
394 FreeBSD/aarch64 aarch64*-*-freebsd*
395 FreeBSD/arm arm*-*-freebsd*
399 FreeBSD/aarch64 aarch64*-*-freebsd*
400 FreeBSD/arm arm*-*-freebsd*
401 OpenRISC ELF or1k*-*-elf
403 * Removed targets and native configurations
405 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
407 *** Changes in GDB 8.0
409 * GDB now supports access to the PKU register on GNU/Linux. The register is
410 added by the Memory Protection Keys for Userspace feature which will be
411 available in future Intel CPUs.
413 * GDB now supports C++11 rvalue references.
417 ** New functions to start, stop and access a running btrace recording.
418 ** Rvalue references are now supported in gdb.Type.
420 * GDB now supports recording and replaying rdrand and rdseed Intel 64
423 * Building GDB and GDBserver now requires a C++11 compiler.
425 For example, GCC 4.8 or later.
427 It is no longer possible to build GDB or GDBserver with a C
428 compiler. The --disable-build-with-cxx configure option has been
431 * Building GDB and GDBserver now requires GNU make >= 3.81.
433 It is no longer supported to build GDB or GDBserver with another
434 implementation of the make program or an earlier version of GNU make.
436 * Native debugging on MS-Windows supports command-line redirection
438 Command-line arguments used for starting programs on MS-Windows can
439 now include redirection symbols supported by native Windows shells,
440 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
441 as "run", "start", and "set args", as well as the corresponding MI
444 * Support for thread names on MS-Windows.
446 GDB now catches and handles the special exception that programs
447 running on MS-Windows use to assign names to threads in the
450 * Support for Java programs compiled with gcj has been removed.
452 * User commands now accept an unlimited number of arguments.
453 Previously, only up to 10 was accepted.
455 * The "eval" command now expands user-defined command arguments.
457 This makes it easier to process a variable number of arguments:
462 eval "print $arg%d", $i
467 * Target descriptions can now describe registers for sparc32 and sparc64.
469 * GDB now supports DWARF version 5 (debug information format).
470 Its .debug_names index is not yet supported.
472 * New native configurations
474 FreeBSD/mips mips*-*-freebsd
478 Synopsys ARC arc*-*-elf32
479 FreeBSD/mips mips*-*-freebsd
481 * Removed targets and native configurations
483 Alpha running FreeBSD alpha*-*-freebsd*
484 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
489 Erases all the flash memory regions reported by the target.
491 maint print arc arc-instruction address
492 Print internal disassembler information about instruction at a given address.
496 set disassembler-options
497 show disassembler-options
498 Controls the passing of target specific information to the disassembler.
499 If it is necessary to specify more than one disassembler option then
500 multiple options can be placed together into a comma separated list.
501 The default value is the empty string. Currently, the only supported
502 targets are ARM, PowerPC and S/390.
507 Erases all the flash memory regions reported by the target. This is
508 equivalent to the CLI command flash-erase.
510 -file-list-shared-libraries
511 List the shared libraries in the program. This is
512 equivalent to the CLI command "info shared".
515 Catchpoints stopping the program when Ada exceptions are
516 handled. This is equivalent to the CLI command "catch handlers".
518 *** Changes in GDB 7.12
520 * GDB and GDBserver now build with a C++ compiler by default.
522 The --enable-build-with-cxx configure option is now enabled by
523 default. One must now explicitly configure with
524 --disable-build-with-cxx in order to build with a C compiler. This
525 option will be removed in a future release.
527 * GDBserver now supports recording btrace without maintaining an active
530 * GDB now supports a negative repeat count in the 'x' command to examine
531 memory backward from the given address. For example:
534 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
535 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
536 (gdb) x/-5i 0x0000000000400580
537 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
538 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
539 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
540 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
541 0x40057b <main(int, char**)+25>:
542 callq 0x400536 <Func1(int, char const*)>
544 * Fortran: Support structures with fields of dynamic types and
545 arrays of dynamic types.
547 * The symbol dumping maintenance commands have new syntax.
548 maint print symbols [-pc address] [--] [filename]
549 maint print symbols [-objfile objfile] [-source source] [--] [filename]
550 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
551 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
552 maint print msymbols [-objfile objfile] [--] [filename]
554 * GDB now supports multibit bitfields and enums in target register
557 * New Python-based convenience function $_as_string(val), which returns
558 the textual representation of a value. This function is especially
559 useful to obtain the text label of an enum value.
561 * Intel MPX bound violation handling.
563 Segmentation faults caused by a Intel MPX boundary violation
564 now display the kind of violation (upper or lower), the memory
565 address accessed and the memory bounds, along with the usual
566 signal received and code location.
570 Program received signal SIGSEGV, Segmentation fault
571 Upper bound violation while accessing address 0x7fffffffc3b3
572 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
573 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
575 * Rust language support.
576 GDB now supports debugging programs written in the Rust programming
577 language. See https://www.rust-lang.org/ for more information about
580 * Support for running interpreters on specified input/output devices
582 GDB now supports a new mechanism that allows frontends to provide
583 fully featured GDB console views, as a better alternative to
584 building such views on top of the "-interpreter-exec console"
585 command. See the new "new-ui" command below. With that command,
586 frontends can now start GDB in the traditional command-line mode
587 running in an embedded terminal emulator widget, and create a
588 separate MI interpreter running on a specified i/o device. In this
589 way, GDB handles line editing, history, tab completion, etc. in the
590 console all by itself, and the GUI uses the separate MI interpreter
591 for its own control and synchronization, invisible to the command
594 * The "catch syscall" command catches groups of related syscalls.
596 The "catch syscall" command now supports catching a group of related
597 syscalls using the 'group:' or 'g:' prefix.
602 skip -gfile file-glob-pattern
603 skip -function function
604 skip -rfunction regular-expression
605 A generalized form of the skip command, with new support for
606 glob-style file names and regular expressions for function names.
607 Additionally, a file spec and a function spec may now be combined.
609 maint info line-table REGEXP
610 Display the contents of GDB's internal line table data struture.
613 Run any GDB unit tests that were compiled in.
616 Start a new user interface instance running INTERP as interpreter,
617 using the TTY file for input/output.
621 ** gdb.Breakpoint objects have a new attribute "pending", which
622 indicates whether the breakpoint is pending.
623 ** Three new breakpoint-related events have been added:
624 gdb.breakpoint_created, gdb.breakpoint_modified, and
625 gdb.breakpoint_deleted.
628 Signal ("set") the given MS-Windows event object. This is used in
629 conjunction with the Windows JIT debugging (AeDebug) support, where
630 the OS suspends a crashing process until a debugger can attach to
631 it. Resuming the crashing process, in order to debug it, is done by
634 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
635 was added in GDBserver, including JIT compiling fast tracepoint's
636 conditional expression bytecode into native code.
638 * Support for various remote target protocols and ROM monitors has
641 target m32rsdi Remote M32R debugging over SDI
642 target mips MIPS remote debugging protocol
643 target pmon PMON ROM monitor
644 target ddb NEC's DDB variant of PMON for Vr4300
645 target rockhopper NEC RockHopper variant of PMON
646 target lsi LSI variant of PMO
648 * Support for tracepoints and fast tracepoints on powerpc-linux,
649 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
650 including JIT compiling fast tracepoint's conditional expression
651 bytecode into native code.
653 * MI async record =record-started now includes the method and format used for
654 recording. For example:
656 =record-started,thread-group="i1",method="btrace",format="bts"
658 * MI async record =thread-selected now includes the frame field. For example:
660 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
664 Andes NDS32 nds32*-*-elf
666 *** Changes in GDB 7.11
668 * GDB now supports debugging kernel-based threads on FreeBSD.
670 * Per-inferior thread numbers
672 Thread numbers are now per inferior instead of global. If you're
673 debugging multiple inferiors, GDB displays thread IDs using a
674 qualified INF_NUM.THR_NUM form. For example:
678 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
679 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
680 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
681 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
683 As consequence, thread numbers as visible in the $_thread
684 convenience variable and in Python's InferiorThread.num attribute
685 are no longer unique between inferiors.
687 GDB now maintains a second thread ID per thread, referred to as the
688 global thread ID, which is the new equivalent of thread numbers in
689 previous releases. See also $_gthread below.
691 For backwards compatibility, MI's thread IDs always refer to global
694 * Commands that accept thread IDs now accept the qualified
695 INF_NUM.THR_NUM form as well. For example:
698 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
701 * In commands that accept a list of thread IDs, you can now refer to
702 all threads of an inferior using a star wildcard. GDB accepts
703 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
704 refer to all threads of the current inferior. For example, "info
707 * You can use "info threads -gid" to display the global thread ID of
710 * The new convenience variable $_gthread holds the global number of
713 * The new convenience variable $_inferior holds the number of the
716 * GDB now displays the ID and name of the thread that hit a breakpoint
717 or received a signal, if your program is multi-threaded. For
720 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
721 Thread 1 "main" received signal SIGINT, Interrupt.
723 * Record btrace now supports non-stop mode.
725 * Support for tracepoints on aarch64-linux was added in GDBserver.
727 * The 'record instruction-history' command now indicates speculative execution
728 when using the Intel Processor Trace recording format.
730 * GDB now allows users to specify explicit locations, bypassing
731 the linespec parser. This feature is also available to GDB/MI
734 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
735 GDB now is able to debug both AArch64 applications and ARM applications
738 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
739 including JIT compiling fast tracepoint's conditional expression bytecode
742 * GDB now supports displaced stepping on AArch64 GNU/Linux.
744 * "info threads", "info inferiors", "info display", "info checkpoints"
745 and "maint info program-spaces" now list the corresponding items in
746 ascending ID order, for consistency with all other "info" commands.
748 * In Ada, the overloads selection menu has been enhanced to display the
749 parameter types and the return types for the matching overloaded subprograms.
753 maint set target-non-stop (on|off|auto)
754 maint show target-non-stop
755 Control whether GDB targets always operate in non-stop mode even if
756 "set non-stop" is "off". The default is "auto", meaning non-stop
757 mode is enabled if supported by the target.
759 maint set bfd-sharing
760 maint show bfd-sharing
761 Control the reuse of bfd objects.
765 Control display of debugging info regarding bfd caching.
769 Control display of debugging info regarding FreeBSD threads.
771 set remote multiprocess-extensions-packet
772 show remote multiprocess-extensions-packet
773 Set/show the use of the remote protocol multiprocess extensions.
775 set remote thread-events
776 show remote thread-events
777 Set/show the use of thread create/exit events.
779 set ada print-signatures on|off
780 show ada print-signatures"
781 Control whether parameter types and return types are displayed in overloads
782 selection menus. It is activaled (@code{on}) by default.
786 Controls the maximum size of memory, in bytes, that GDB will
787 allocate for value contents. Prevents incorrect programs from
788 causing GDB to allocate overly large buffers. Default is 64k.
790 * The "disassemble" command accepts a new modifier: /s.
791 It prints mixed source+disassembly like /m with two differences:
792 - disassembled instructions are now printed in program order, and
793 - and source for all relevant files is now printed.
794 The "/m" option is now considered deprecated: its "source-centric"
795 output hasn't proved useful in practice.
797 * The "record instruction-history" command accepts a new modifier: /s.
798 It behaves exactly like /m and prints mixed source+disassembly.
800 * The "set scheduler-locking" command supports a new mode "replay".
801 It behaves like "off" in record mode and like "on" in replay mode.
803 * Support for various ROM monitors has been removed:
805 target dbug dBUG ROM monitor for Motorola ColdFire
806 target picobug Motorola picobug monitor
807 target dink32 DINK32 ROM monitor for PowerPC
808 target m32r Renesas M32R/D ROM monitor
809 target mon2000 mon2000 ROM monitor
810 target ppcbug PPCBUG ROM monitor for PowerPC
812 * Support for reading/writing memory and extracting values on architectures
813 whose memory is addressable in units of any integral multiple of 8 bits.
816 Allows to break when an Ada exception is handled.
821 Indicates that an exec system call was executed.
823 exec-events feature in qSupported
824 The qSupported packet allows GDB to request support for exec
825 events using the new 'gdbfeature' exec-event, and the qSupported
826 response can contain the corresponding 'stubfeature'. Set and
827 show commands can be used to display whether these features are enabled.
830 Equivalent to interrupting with the ^C character, but works in
833 thread created stop reason (T05 create:...)
834 Indicates that the thread was just created and is stopped at entry.
836 thread exit stop reply (w exitcode;tid)
837 Indicates that the thread has terminated.
840 Enables/disables thread create and exit event reporting. For
841 example, this is used in non-stop mode when GDB stops a set of
842 threads and synchronously waits for the their corresponding stop
843 replies. Without exit events, if one of the threads exits, GDB
844 would hang forever not knowing that it should no longer expect a
845 stop for that same thread.
848 Indicates that there are no resumed threads left in the target (all
849 threads are stopped). The remote stub reports support for this stop
850 reply to GDB's qSupported query.
853 Enables/disables catching syscalls from the inferior process.
854 The remote stub reports support for this packet to GDB's qSupported query.
856 syscall_entry stop reason
857 Indicates that a syscall was just called.
859 syscall_return stop reason
860 Indicates that a syscall just returned.
862 * Extended-remote exec events
864 ** GDB now has support for exec events on extended-remote Linux targets.
865 For such targets with Linux kernels 2.5.46 and later, this enables
866 follow-exec-mode and exec catchpoints.
868 set remote exec-event-feature-packet
869 show remote exec-event-feature-packet
870 Set/show the use of the remote exec event feature.
872 * Thread names in remote protocol
874 The reply to qXfer:threads:read may now include a name attribute for each
877 * Target remote mode fork and exec events
879 ** GDB now has support for fork and exec events on target remote mode
880 Linux targets. For such targets with Linux kernels 2.5.46 and later,
881 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
882 fork and exec catchpoints.
884 * Remote syscall events
886 ** GDB now has support for catch syscall on remote Linux targets,
887 currently enabled on x86/x86_64 architectures.
889 set remote catch-syscall-packet
890 show remote catch-syscall-packet
891 Set/show the use of the remote catch syscall feature.
895 ** The -var-set-format command now accepts the zero-hexadecimal
896 format. It outputs data in hexadecimal format with zero-padding on the
901 ** gdb.InferiorThread objects have a new attribute "global_num",
902 which refers to the thread's global thread ID. The existing
903 "num" attribute now refers to the thread's per-inferior number.
904 See "Per-inferior thread numbers" above.
905 ** gdb.InferiorThread objects have a new attribute "inferior", which
906 is the Inferior object the thread belongs to.
908 *** Changes in GDB 7.10
910 * Support for process record-replay and reverse debugging on aarch64*-linux*
911 targets has been added. GDB now supports recording of A64 instruction set
912 including advance SIMD instructions.
914 * Support for Sun's version of the "stabs" debug file format has been removed.
916 * GDB now honors the content of the file /proc/PID/coredump_filter
917 (PID is the process ID) on GNU/Linux systems. This file can be used
918 to specify the types of memory mappings that will be included in a
919 corefile. For more information, please refer to the manual page of
920 "core(5)". GDB also has a new command: "set use-coredump-filter
921 on|off". It allows to set whether GDB will read the content of the
922 /proc/PID/coredump_filter file when generating a corefile.
924 * The "info os" command on GNU/Linux can now display information on
926 "info os cpus" Listing of all cpus/cores on the system
928 * GDB has two new commands: "set serial parity odd|even|none" and
929 "show serial parity". These allows to set or show parity for the
932 * The "info source" command now displays the producer string if it was
933 present in the debug info. This typically includes the compiler version
934 and may include things like its command line arguments.
936 * The "info dll", an alias of the "info sharedlibrary" command,
937 is now available on all platforms.
939 * Directory names supplied to the "set sysroot" commands may be
940 prefixed with "target:" to tell GDB to access shared libraries from
941 the target system, be it local or remote. This replaces the prefix
942 "remote:". The default sysroot has been changed from "" to
943 "target:". "remote:" is automatically converted to "target:" for
944 backward compatibility.
946 * The system root specified by "set sysroot" will be prepended to the
947 filename of the main executable (if reported to GDB as absolute by
948 the operating system) when starting processes remotely, and when
949 attaching to already-running local or remote processes.
951 * GDB now supports automatic location and retrieval of executable
952 files from remote targets. Remote debugging can now be initiated
953 using only a "target remote" or "target extended-remote" command
954 (no "set sysroot" or "file" commands are required). See "New remote
957 * The "dump" command now supports verilog hex format.
959 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
961 * On GNU/Linux, GDB and gdbserver are now able to access executable
962 and shared library files without a "set sysroot" command when
963 attaching to processes running in different mount namespaces from
964 the debugger. This makes it possible to attach to processes in
965 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
966 See "New remote packets" below.
968 * The "tui reg" command now provides completion for all of the
969 available register groups, including target specific groups.
971 * The HISTSIZE environment variable is no longer read when determining
972 the size of GDB's command history. GDB now instead reads the dedicated
973 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
974 disables truncation of command history. Non-numeric values of GDBHISTSIZE
979 ** Memory ports can now be unbuffered.
983 ** gdb.Objfile objects have a new attribute "username",
984 which is the name of the objfile as specified by the user,
985 without, for example, resolving symlinks.
986 ** You can now write frame unwinders in Python.
987 ** gdb.Type objects have a new method "optimized_out",
988 returning optimized out gdb.Value instance of this type.
989 ** gdb.Value objects have new methods "reference_value" and
990 "const_value" which return a reference to the value and a
991 "const" version of the value respectively.
995 maint print symbol-cache
996 Print the contents of the symbol cache.
998 maint print symbol-cache-statistics
999 Print statistics of symbol cache usage.
1001 maint flush-symbol-cache
1002 Flush the contents of the symbol cache.
1006 Start branch trace recording using Branch Trace Store (BTS) format.
1009 Evaluate expression by using the compiler and print result.
1013 Explicit commands for enabling and disabling tui mode.
1016 set mpx bound on i386 and amd64
1017 Support for bound table investigation on Intel MPX enabled applications.
1021 Start branch trace recording using Intel Processor Trace format.
1024 Print information about branch tracing internals.
1026 maint btrace packet-history
1027 Print the raw branch tracing data.
1029 maint btrace clear-packet-history
1030 Discard the stored raw branch tracing data.
1033 Discard all branch tracing data. It will be fetched and processed
1034 anew by the next "record" command.
1039 Renamed from "set debug dwarf2-die".
1040 show debug dwarf-die
1041 Renamed from "show debug dwarf2-die".
1043 set debug dwarf-read
1044 Renamed from "set debug dwarf2-read".
1045 show debug dwarf-read
1046 Renamed from "show debug dwarf2-read".
1048 maint set dwarf always-disassemble
1049 Renamed from "maint set dwarf2 always-disassemble".
1050 maint show dwarf always-disassemble
1051 Renamed from "maint show dwarf2 always-disassemble".
1053 maint set dwarf max-cache-age
1054 Renamed from "maint set dwarf2 max-cache-age".
1055 maint show dwarf max-cache-age
1056 Renamed from "maint show dwarf2 max-cache-age".
1058 set debug dwarf-line
1059 show debug dwarf-line
1060 Control display of debugging info regarding DWARF line processing.
1063 show max-completions
1064 Set the maximum number of candidates to be considered during
1065 completion. The default value is 200. This limit allows GDB
1066 to avoid generating large completion lists, the computation of
1067 which can cause the debugger to become temporarily unresponsive.
1069 set history remove-duplicates
1070 show history remove-duplicates
1071 Control the removal of duplicate history entries.
1073 maint set symbol-cache-size
1074 maint show symbol-cache-size
1075 Control the size of the symbol cache.
1077 set|show record btrace bts buffer-size
1078 Set and show the size of the ring buffer used for branch tracing in
1080 The obtained size may differ from the requested size. Use "info
1081 record" to see the obtained buffer size.
1083 set debug linux-namespaces
1084 show debug linux-namespaces
1085 Control display of debugging info regarding Linux namespaces.
1087 set|show record btrace pt buffer-size
1088 Set and show the size of the ring buffer used for branch tracing in
1089 Intel Processor Trace format.
1090 The obtained size may differ from the requested size. Use "info
1091 record" to see the obtained buffer size.
1093 maint set|show btrace pt skip-pad
1094 Set and show whether PAD packets are skipped when computing the
1097 * The command 'thread apply all' can now support new option '-ascending'
1098 to call its specified command for all threads in ascending order.
1100 * Python/Guile scripting
1102 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1103 special section named `.debug_gdb_scripts'.
1105 * New remote packets
1107 qXfer:btrace-conf:read
1108 Return the branch trace configuration for the current thread.
1110 Qbtrace-conf:bts:size
1111 Set the requested ring buffer size for branch tracing in BTS format.
1114 Enable Intel Procesor Trace-based branch tracing for the current
1115 process. The remote stub reports support for this packet to GDB's
1118 Qbtrace-conf:pt:size
1119 Set the requested ring buffer size for branch tracing in Intel Processor
1123 Indicates a memory breakpoint instruction was executed, irrespective
1124 of whether it was GDB that planted the breakpoint or the breakpoint
1125 is hardcoded in the program. This is required for correct non-stop
1129 Indicates the target stopped for a hardware breakpoint. This is
1130 required for correct non-stop mode operation.
1133 Return information about files on the remote system.
1135 qXfer:exec-file:read
1136 Return the full absolute name of the file that was executed to
1137 create a process running on the remote system.
1140 Select the filesystem on which vFile: operations with filename
1141 arguments will operate. This is required for GDB to be able to
1142 access files on remote targets where the remote stub does not
1143 share a common filesystem with the inferior(s).
1146 Indicates that a fork system call was executed.
1149 Indicates that a vfork system call was executed.
1151 vforkdone stop reason
1152 Indicates that a vfork child of the specified process has executed
1153 an exec or exit, allowing the vfork parent to resume execution.
1155 fork-events and vfork-events features in qSupported
1156 The qSupported packet allows GDB to request support for fork and
1157 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1158 and the qSupported response can contain the corresponding
1159 'stubfeatures'. Set and show commands can be used to display
1160 whether these features are enabled.
1162 * Extended-remote fork events
1164 ** GDB now has support for fork events on extended-remote Linux
1165 targets. For targets with Linux kernels 2.5.60 and later, this
1166 enables follow-fork-mode and detach-on-fork for both fork and
1167 vfork, as well as fork and vfork catchpoints.
1169 * The info record command now shows the recording format and the
1170 branch tracing configuration for the current thread when using
1171 the btrace record target.
1172 For the BTS format, it shows the ring buffer size.
1174 * GDB now has support for DTrace USDT (Userland Static Defined
1175 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1177 * GDB now supports access to vector registers on S/390 GNU/Linux
1180 * Removed command line options
1182 -xdb HP-UX XDB compatibility mode.
1184 * Removed targets and native configurations
1186 HP/PA running HP-UX hppa*-*-hpux*
1187 Itanium running HP-UX ia64-*-hpux*
1189 * New configure options
1192 This configure option allows the user to build GDB with support for
1193 Intel Processor Trace (default: auto). This requires libipt.
1195 --with-libipt-prefix=PATH
1196 Specify the path to the version of libipt that GDB should use.
1197 $PATH/include should contain the intel-pt.h header and
1198 $PATH/lib should contain the libipt.so library.
1200 *** Changes in GDB 7.9.1
1204 ** Xmethods can now specify a result type.
1206 *** Changes in GDB 7.9
1208 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1212 ** You can now access frame registers from Python scripts.
1213 ** New attribute 'producer' for gdb.Symtab objects.
1214 ** gdb.Objfile objects have a new attribute "progspace",
1215 which is the gdb.Progspace object of the containing program space.
1216 ** gdb.Objfile objects have a new attribute "owner".
1217 ** gdb.Objfile objects have a new attribute "build_id",
1218 which is the build ID generated when the file was built.
1219 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1220 ** A new event "gdb.clear_objfiles" has been added, triggered when
1221 selecting a new file to debug.
1222 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1223 ** New function gdb.lookup_objfile.
1225 New events which are triggered when GDB modifies the state of the
1228 ** gdb.events.inferior_call_pre: Function call is about to be made.
1229 ** gdb.events.inferior_call_post: Function call has just been made.
1230 ** gdb.events.memory_changed: A memory location has been altered.
1231 ** gdb.events.register_changed: A register has been altered.
1233 * New Python-based convenience functions:
1235 ** $_caller_is(name [, number_of_frames])
1236 ** $_caller_matches(regexp [, number_of_frames])
1237 ** $_any_caller_is(name [, number_of_frames])
1238 ** $_any_caller_matches(regexp [, number_of_frames])
1240 * GDB now supports the compilation and injection of source code into
1241 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1242 to compile the source code to object code, and if successful, inject
1243 and execute that code within the current context of the inferior.
1244 Currently the C language is supported. The commands used to
1245 interface with this new feature are:
1247 compile code [-raw|-r] [--] [source code]
1248 compile file [-raw|-r] filename
1252 demangle [-l language] [--] name
1253 Demangle "name" in the specified language, or the current language
1254 if elided. This command is renamed from the "maint demangle" command.
1255 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1256 as "maint demangler-warning".
1258 queue-signal signal-name-or-number
1259 Queue a signal to be delivered to the thread when it is resumed.
1261 add-auto-load-scripts-directory directory
1262 Add entries to the list of directories from which to load auto-loaded
1265 maint print user-registers
1266 List all currently available "user" registers.
1268 compile code [-r|-raw] [--] [source code]
1269 Compile, inject, and execute in the inferior the executable object
1270 code produced by compiling the provided source code.
1272 compile file [-r|-raw] filename
1273 Compile and inject into the inferior the executable object code
1274 produced by compiling the source code stored in the filename
1277 * On resume, GDB now always passes the signal the program had stopped
1278 for to the thread the signal was sent to, even if the user changed
1279 threads before resuming. Previously GDB would often (but not
1280 always) deliver the signal to the thread that happens to be current
1283 * Conversely, the "signal" command now consistently delivers the
1284 requested signal to the current thread. GDB now asks for
1285 confirmation if the program had stopped for a signal and the user
1286 switched threads meanwhile.
1288 * "breakpoint always-inserted" modes "off" and "auto" merged.
1290 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1291 won't remove breakpoints from the target until all threads stop,
1292 even in non-stop mode. The "auto" mode has been removed, and "off"
1293 is now the default mode.
1297 set debug symbol-lookup
1298 show debug symbol-lookup
1299 Control display of debugging info regarding symbol lookup.
1303 ** The -list-thread-groups command outputs an exit-code field for
1304 inferiors that have exited.
1308 MIPS SDE mips*-sde*-elf*
1312 Support for these obsolete configurations has been removed.
1314 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1315 SGI Irix-5.x mips-*-irix5*
1316 SGI Irix-6.x mips-*-irix6*
1317 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1318 VAX running Ultrix vax-*-ultrix*
1320 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1321 and "assf"), have been removed. Use the "sharedlibrary" command, or
1322 its alias "share", instead.
1324 *** Changes in GDB 7.8
1326 * New command line options
1329 This is an alias for the --data-directory option.
1331 * GDB supports printing and modifying of variable length automatic arrays
1332 as specified in ISO C99.
1334 * The ARM simulator now supports instruction level tracing
1335 with or without disassembly.
1339 GDB now has support for scripting using Guile. Whether this is
1340 available is determined at configure time.
1341 Guile version 2.0 or greater is required.
1342 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1344 * New commands (for set/show, see "New options" below)
1348 Invoke CODE by passing it to the Guile interpreter.
1352 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1354 info auto-load guile-scripts [regexp]
1355 Print the list of automatically loaded Guile scripts.
1357 * The source command is now capable of sourcing Guile scripts.
1358 This feature is dependent on the debugger being built with Guile support.
1362 set print symbol-loading (off|brief|full)
1363 show print symbol-loading
1364 Control whether to print informational messages when loading symbol
1365 information for a file. The default is "full", but when debugging
1366 programs with large numbers of shared libraries the amount of output
1367 becomes less useful.
1369 set guile print-stack (none|message|full)
1370 show guile print-stack
1371 Show a stack trace when an error is encountered in a Guile script.
1373 set auto-load guile-scripts (on|off)
1374 show auto-load guile-scripts
1375 Control auto-loading of Guile script files.
1377 maint ada set ignore-descriptive-types (on|off)
1378 maint ada show ignore-descriptive-types
1379 Control whether the debugger should ignore descriptive types in Ada
1380 programs. The default is not to ignore the descriptive types. See
1381 the user manual for more details on descriptive types and the intended
1382 usage of this option.
1384 set auto-connect-native-target
1386 Control whether GDB is allowed to automatically connect to the
1387 native target for the run, attach, etc. commands when not connected
1388 to any target yet. See also "target native" below.
1390 set record btrace replay-memory-access (read-only|read-write)
1391 show record btrace replay-memory-access
1392 Control what memory accesses are allowed during replay.
1394 maint set target-async (on|off)
1395 maint show target-async
1396 This controls whether GDB targets operate in synchronous or
1397 asynchronous mode. Normally the default is asynchronous, if it is
1398 available; but this can be changed to more easily debug problems
1399 occurring only in synchronous mode.
1401 set mi-async (on|off)
1403 Control whether MI asynchronous mode is preferred. This supersedes
1404 "set target-async" of previous GDB versions.
1406 * "set target-async" is deprecated as a CLI option and is now an alias
1407 for "set mi-async" (only puts MI into async mode).
1409 * Background execution commands (e.g., "c&", "s&", etc.) are now
1410 possible ``out of the box'' if the target supports them. Previously
1411 the user would need to explicitly enable the possibility with the
1412 "set target-async on" command.
1414 * New features in the GDB remote stub, GDBserver
1416 ** New option --debug-format=option1[,option2,...] allows one to add
1417 additional text to each output. At present only timestamps
1418 are supported: --debug-format=timestamps.
1419 Timestamps can also be turned on with the
1420 "monitor set debug-format timestamps" command from GDB.
1422 * The 'record instruction-history' command now starts counting instructions
1423 at one. This also affects the instruction ranges reported by the
1424 'record function-call-history' command when given the /i modifier.
1426 * The command 'record function-call-history' supports a new modifier '/c' to
1427 indent the function names based on their call stack depth.
1428 The fields for the '/i' and '/l' modifier have been reordered.
1429 The source line range is now prefixed with 'at'.
1430 The instruction range is now prefixed with 'inst'.
1431 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1432 "record instruction-history" and "list" commands.
1434 * The ranges given as arguments to the 'record function-call-history' and
1435 'record instruction-history' commands are now inclusive.
1437 * The btrace record target now supports the 'record goto' command.
1438 For locations inside the execution trace, the back trace is computed
1439 based on the information stored in the execution trace.
1441 * The btrace record target supports limited reverse execution and replay.
1442 The target does not record data and therefore does not allow reading
1443 memory or registers.
1445 * The "catch syscall" command now works on s390*-linux* targets.
1447 * The "compare-sections" command is no longer specific to target
1448 remote. It now works with all targets.
1450 * All native targets are now consistently called "native".
1451 Consequently, the "target child", "target GNU", "target djgpp",
1452 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1453 commands have been replaced with "target native". The QNX/NTO port
1454 leaves the "procfs" target in place and adds a "native" target for
1455 consistency with other ports. The impact on users should be minimal
1456 as these commands previously either throwed an error, or were
1457 no-ops. The target's name is visible in the output of the following
1458 commands: "help target", "info target", "info files", "maint print
1461 * The "target native" command now connects to the native target. This
1462 can be used to launch native programs even when "set
1463 auto-connect-native-target" is set to off.
1465 * GDB now supports access to Intel MPX registers on GNU/Linux.
1467 * Support for Intel AVX-512 registers on GNU/Linux.
1468 Support displaying and modifying Intel AVX-512 registers
1469 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1471 * New remote packets
1473 qXfer:btrace:read's annex
1474 The qXfer:btrace:read packet supports a new annex 'delta' to read
1475 branch trace incrementally.
1479 ** Valid Python operations on gdb.Value objects representing
1480 structs/classes invoke the corresponding overloaded operators if
1482 ** New `Xmethods' feature in the Python API. Xmethods are
1483 additional methods or replacements for existing methods of a C++
1484 class. This feature is useful for those cases where a method
1485 defined in C++ source code could be inlined or optimized out by
1486 the compiler, making it unavailable to GDB.
1489 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1491 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1492 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1493 its alias "share", instead.
1495 * The commands "set remotebaud" and "show remotebaud" are no longer
1496 supported. Use "set serial baud" and "show serial baud" (respectively)
1501 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1502 target-async". The latter is left as a deprecated alias of the
1503 former for backward compatibility. If the target supports it,
1504 CLI background execution commands are now always possible by
1505 default, independently of whether the frontend stated a
1506 preference for asynchronous execution with "-gdb-set mi-async".
1507 Previously "-gdb-set target-async off" affected both MI execution
1508 commands and CLI execution commands.
1510 *** Changes in GDB 7.7
1512 * Improved support for process record-replay and reverse debugging on
1513 arm*-linux* targets. Support for thumb32 and syscall instruction
1514 recording has been added.
1516 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1518 * GDB now supports Fission DWP file format version 2.
1519 http://gcc.gnu.org/wiki/DebugFission
1521 * New convenience function "$_isvoid", to check whether an expression
1522 is void. A void expression is an expression where the type of the
1523 result is "void". For example, some convenience variables may be
1524 "void" when evaluated (e.g., "$_exitcode" before the execution of
1525 the program being debugged; or an undefined convenience variable).
1526 Another example, when calling a function whose return type is
1529 * The "maintenance print objfiles" command now takes an optional regexp.
1531 * The "catch syscall" command now works on arm*-linux* targets.
1533 * GDB now consistently shows "<not saved>" when printing values of
1534 registers the debug info indicates have not been saved in the frame
1535 and there's nowhere to retrieve them from
1536 (callee-saved/call-clobbered registers):
1541 (gdb) info registers rax
1544 Before, the former would print "<optimized out>", and the latter
1545 "*value not available*".
1547 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1552 ** Frame filters and frame decorators have been added.
1553 ** Temporary breakpoints are now supported.
1554 ** Line tables representation has been added.
1555 ** New attribute 'parent_type' for gdb.Field objects.
1556 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1557 ** New attribute 'name' for gdb.Type objects.
1561 Nios II ELF nios2*-*-elf
1562 Nios II GNU/Linux nios2*-*-linux
1563 Texas Instruments MSP430 msp430*-*-elf
1565 * Removed native configurations
1567 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1568 been removed. ELF variants of these configurations are kept supported.
1570 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1571 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1572 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1573 i[34567]86-*-openbsd3.[0-3]
1574 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1575 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1576 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1580 Like "catch throw", but catches a re-thrown exception.
1581 maint check-psymtabs
1582 Renamed from old "maint check-symtabs".
1584 Perform consistency checks on symtabs.
1585 maint expand-symtabs
1586 Expand symtabs matching an optional regexp.
1589 Display the details of GDB configure-time options.
1591 maint set|show per-command
1592 maint set|show per-command space
1593 maint set|show per-command time
1594 maint set|show per-command symtab
1595 Enable display of per-command gdb resource usage.
1597 remove-symbol-file FILENAME
1598 remove-symbol-file -a ADDRESS
1599 Remove a symbol file added via add-symbol-file. The file to remove
1600 can be identified by its filename or by an address that lies within
1601 the boundaries of this symbol file in memory.
1604 info exceptions REGEXP
1605 Display the list of Ada exceptions defined in the program being
1606 debugged. If provided, only the exceptions whose names match REGEXP
1611 set debug symfile off|on
1613 Control display of debugging info regarding reading symbol files and
1614 symbol tables within those files
1616 set print raw frame-arguments
1617 show print raw frame-arguments
1618 Set/show whether to print frame arguments in raw mode,
1619 disregarding any defined pretty-printers.
1621 set remote trace-status-packet
1622 show remote trace-status-packet
1623 Set/show the use of remote protocol qTStatus packet.
1627 Control display of debugging messages related to Nios II targets.
1631 Control whether target-assisted range stepping is enabled.
1633 set startup-with-shell
1634 show startup-with-shell
1635 Specifies whether Unix child processes are started via a shell or
1640 Use the target memory cache for accesses to the code segment. This
1641 improves performance of remote debugging (particularly disassembly).
1643 * You can now use a literal value 'unlimited' for options that
1644 interpret 0 or -1 as meaning "unlimited". E.g., "set
1645 trace-buffer-size unlimited" is now an alias for "set
1646 trace-buffer-size -1" and "set height unlimited" is now an alias for
1649 * The "set debug symtab-create" debugging option of GDB has been changed to
1650 accept a verbosity level. 0 means "off", 1 provides basic debugging
1651 output, and values of 2 or greater provides more verbose output.
1653 * New command-line options
1655 Display the details of GDB configure-time options.
1657 * The command 'tsave' can now support new option '-ctf' to save trace
1658 buffer in Common Trace Format.
1660 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1663 * GDB now implements the the C++ 'typeid' operator.
1665 * The new convenience variable $_exception holds the exception being
1666 thrown or caught at an exception-related catchpoint.
1668 * The exception-related catchpoints, like "catch throw", now accept a
1669 regular expression which can be used to filter exceptions by type.
1671 * The new convenience variable $_exitsignal is automatically set to
1672 the terminating signal number when the program being debugged dies
1673 due to an uncaught signal.
1677 ** All MI commands now accept an optional "--language" option.
1678 Support for this feature can be verified by using the "-list-features"
1679 command, which should contain "language-option".
1681 ** The new command -info-gdb-mi-command allows the user to determine
1682 whether a GDB/MI command is supported or not.
1684 ** The "^error" result record returned when trying to execute an undefined
1685 GDB/MI command now provides a variable named "code" whose content is the
1686 "undefined-command" error code. Support for this feature can be verified
1687 by using the "-list-features" command, which should contain
1688 "undefined-command-error-code".
1690 ** The -trace-save MI command can optionally save trace buffer in Common
1693 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1695 ** The command -data-list-register-values now accepts an optional
1696 "--skip-unavailable" option. When used, only the available registers
1699 ** The new command -trace-frame-collected dumps collected variables,
1700 computed expressions, tvars, memory and registers in a traceframe.
1702 ** The commands -stack-list-locals, -stack-list-arguments and
1703 -stack-list-variables now accept an option "--skip-unavailable".
1704 When used, only the available locals or arguments are displayed.
1706 ** The -exec-run command now accepts an optional "--start" option.
1707 When used, the command follows the same semantics as the "start"
1708 command, stopping the program's execution at the start of its
1709 main subprogram. Support for this feature can be verified using
1710 the "-list-features" command, which should contain
1711 "exec-run-start-option".
1713 ** The new commands -catch-assert and -catch-exceptions insert
1714 catchpoints stopping the program when Ada exceptions are raised.
1716 ** The new command -info-ada-exceptions provides the equivalent of
1717 the new "info exceptions" command.
1719 * New system-wide configuration scripts
1720 A GDB installation now provides scripts suitable for use as system-wide
1721 configuration scripts for the following systems:
1725 * GDB now supports target-assigned range stepping with remote targets.
1726 This improves the performance of stepping source lines by reducing
1727 the number of control packets from/to GDB. See "New remote packets"
1730 * GDB now understands the element 'tvar' in the XML traceframe info.
1731 It has the id of the collected trace state variables.
1733 * On S/390 targets that provide the transactional-execution feature,
1734 the program interruption transaction diagnostic block (TDB) is now
1735 represented as a number of additional "registers" in GDB.
1737 * New remote packets
1741 The vCont packet supports a new 'r' action, that tells the remote
1742 stub to step through an address range itself, without GDB
1743 involvemement at each single-step.
1745 qXfer:libraries-svr4:read's annex
1746 The previously unused annex of the qXfer:libraries-svr4:read packet
1747 is now used to support passing an argument list. The remote stub
1748 reports support for this argument list to GDB's qSupported query.
1749 The defined arguments are "start" and "prev", used to reduce work
1750 necessary for library list updating, resulting in significant
1753 * New features in the GDB remote stub, GDBserver
1755 ** GDBserver now supports target-assisted range stepping. Currently
1756 enabled on x86/x86_64 GNU/Linux targets.
1758 ** GDBserver now adds element 'tvar' in the XML in the reply to
1759 'qXfer:traceframe-info:read'. It has the id of the collected
1760 trace state variables.
1762 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1765 * New 'z' formatter for printing and examining memory, this displays the
1766 value as hexadecimal zero padded on the left to the size of the type.
1768 * GDB can now use Windows x64 unwinding data.
1770 * The "set remotebaud" command has been replaced by "set serial baud".
1771 Similarly, "show remotebaud" has been replaced by "show serial baud".
1772 The "set remotebaud" and "show remotebaud" commands are still available
1773 to provide backward compatibility with older versions of GDB.
1775 *** Changes in GDB 7.6
1777 * Target record has been renamed to record-full.
1778 Record/replay is now enabled with the "record full" command.
1779 This also affects settings that are associated with full record/replay
1780 that have been moved from "set/show record" to "set/show record full":
1782 set|show record full insn-number-max
1783 set|show record full stop-at-limit
1784 set|show record full memory-query
1786 * A new record target "record-btrace" has been added. The new target
1787 uses hardware support to record the control-flow of a process. It
1788 does not support replaying the execution, but it implements the
1789 below new commands for investigating the recorded execution log.
1790 This new recording method can be enabled using:
1794 The "record-btrace" target is only available on Intel Atom processors
1795 and requires a Linux kernel 2.6.32 or later.
1797 * Two new commands have been added for record/replay to give information
1798 about the recorded execution without having to replay the execution.
1799 The commands are only supported by "record btrace".
1801 record instruction-history prints the execution history at
1802 instruction granularity
1804 record function-call-history prints the execution history at
1805 function granularity
1807 * New native configurations
1809 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1810 FreeBSD/powerpc powerpc*-*-freebsd
1811 x86_64/Cygwin x86_64-*-cygwin*
1812 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1816 ARM AArch64 aarch64*-*-elf
1817 ARM AArch64 GNU/Linux aarch64*-*-linux
1818 Lynx 178 PowerPC powerpc-*-lynx*178
1819 x86_64/Cygwin x86_64-*-cygwin*
1820 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1822 * If the configured location of system.gdbinit file (as given by the
1823 --with-system-gdbinit option at configure time) is in the
1824 data-directory (as specified by --with-gdb-datadir at configure
1825 time) or in one of its subdirectories, then GDB will look for the
1826 system-wide init file in the directory specified by the
1827 --data-directory command-line option.
1829 * New command line options:
1831 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1832 other initialization files, unlike -nx which disables all of them.
1834 * Removed command line options
1836 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1839 * The 'ptype' and 'whatis' commands now accept an argument to control
1842 * 'info proc' now works on some core files.
1846 ** Vectors can be created with gdb.Type.vector.
1848 ** Python's atexit.register now works in GDB.
1850 ** Types can be pretty-printed via a Python API.
1852 ** Python 3 is now supported (in addition to Python 2.4 or later)
1854 ** New class gdb.Architecture exposes GDB's internal representation
1855 of architecture in the Python API.
1857 ** New method Frame.architecture returns the gdb.Architecture object
1858 corresponding to the frame's architecture.
1860 * New Python-based convenience functions:
1862 ** $_memeq(buf1, buf2, length)
1863 ** $_streq(str1, str2)
1865 ** $_regex(str, regex)
1867 * The 'cd' command now defaults to using '~' (the home directory) if not
1870 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1871 default for GCC since November 2000.
1873 * The command 'forward-search' can now be abbreviated as 'fo'.
1875 * The command 'info tracepoints' can now display 'installed on target'
1876 or 'not installed on target' for each non-pending location of tracepoint.
1878 * New configure options
1880 --enable-libmcheck/--disable-libmcheck
1881 By default, development versions are built with -lmcheck on hosts
1882 that support it, in order to help track memory corruption issues.
1883 Release versions, on the other hand, are built without -lmcheck
1884 by default. The --enable-libmcheck/--disable-libmcheck configure
1885 options allow the user to override that default.
1886 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1887 This configure option allows the user to build GDB with
1888 libbabeltrace using which GDB can read Common Trace Format data.
1890 * New commands (for set/show, see "New options" below)
1893 Catch signals. This is similar to "handle", but allows commands and
1894 conditions to be attached.
1897 List the BFDs known to GDB.
1899 python-interactive [command]
1901 Start a Python interactive prompt, or evaluate the optional command
1902 and print the result of expressions.
1905 "py" is a new alias for "python".
1907 enable type-printer [name]...
1908 disable type-printer [name]...
1909 Enable or disable type printers.
1913 ** For the Renesas Super-H architecture, the "regs" command has been removed
1914 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1919 set print type methods (on|off)
1920 show print type methods
1921 Control whether method declarations are displayed by "ptype".
1922 The default is to show them.
1924 set print type typedefs (on|off)
1925 show print type typedefs
1926 Control whether typedef definitions are displayed by "ptype".
1927 The default is to show them.
1929 set filename-display basename|relative|absolute
1930 show filename-display
1931 Control the way in which filenames is displayed.
1932 The default is "relative", which preserves previous behavior.
1934 set trace-buffer-size
1935 show trace-buffer-size
1936 Request target to change the size of trace buffer.
1938 set remote trace-buffer-size-packet auto|on|off
1939 show remote trace-buffer-size-packet
1940 Control the use of the remote protocol `QTBuffer:size' packet.
1944 Control display of debugging messages related to ARM AArch64.
1947 set debug coff-pe-read
1948 show debug coff-pe-read
1949 Control display of debugging messages related to reading of COFF/PE
1954 Control display of debugging messages related to Mach-O symbols
1957 set debug notification
1958 show debug notification
1959 Control display of debugging info for async remote notification.
1963 ** Command parameter changes are now notified using new async record
1964 "=cmd-param-changed".
1965 ** Trace frame changes caused by command "tfind" are now notified using
1966 new async record "=traceframe-changed".
1967 ** The creation, deletion and modification of trace state variables
1968 are now notified using new async records "=tsv-created",
1969 "=tsv-deleted" and "=tsv-modified".
1970 ** The start and stop of process record are now notified using new
1971 async record "=record-started" and "=record-stopped".
1972 ** Memory changes are now notified using new async record
1974 ** The data-disassemble command response will include a "fullname" field
1975 containing the absolute file name when source has been requested.
1976 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1977 command, to allow pattern filling of memory areas.
1978 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1979 library load/unload events.
1980 ** The response to breakpoint commands and breakpoint async records
1981 includes an "installed" field containing a boolean state about each
1982 non-pending tracepoint location is whether installed on target or not.
1983 ** Output of the "-trace-status" command includes a "trace-file" field
1984 containing the name of the trace file being examined. This field is
1985 optional, and only present when examining a trace file.
1986 ** The "fullname" field is now always present along with the "file" field,
1987 even if the file cannot be found by GDB.
1989 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1990 You must have the LZMA library available when configuring GDB for this
1991 feature to be enabled. For more information, see:
1992 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1994 * New remote packets
1997 Set the size of trace buffer. The remote stub reports support for this
1998 packet to gdb's qSupported query.
2001 Enable Branch Trace Store (BTS)-based branch tracing for the current
2002 thread. The remote stub reports support for this packet to gdb's
2006 Disable branch tracing for the current thread. The remote stub reports
2007 support for this packet to gdb's qSupported query.
2010 Read the traced branches for the current thread. The remote stub
2011 reports support for this packet to gdb's qSupported query.
2013 *** Changes in GDB 7.5
2015 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2016 for more x32 ABI info.
2018 * GDB now supports access to MIPS DSP registers on Linux targets.
2020 * GDB now supports debugging microMIPS binaries.
2022 * The "info os" command on GNU/Linux can now display information on
2023 several new classes of objects managed by the operating system:
2024 "info os procgroups" lists process groups
2025 "info os files" lists file descriptors
2026 "info os sockets" lists internet-domain sockets
2027 "info os shm" lists shared-memory regions
2028 "info os semaphores" lists semaphores
2029 "info os msg" lists message queues
2030 "info os modules" lists loaded kernel modules
2032 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2033 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2034 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2035 options and inspect the probe arguments using the new $_probe_arg family
2036 of convenience variables. You can obtain more information about SystemTap
2037 in <http://sourceware.org/systemtap/>.
2039 * GDB now supports reversible debugging on ARM, it allows you to
2040 debug basic ARM and THUMB instructions, and provides
2041 record/replay support.
2043 * The option "symbol-reloading" has been deleted as it is no longer used.
2047 ** GDB commands implemented in Python can now be put in command class
2050 ** The "maint set python print-stack on|off" is now deleted.
2052 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2053 apply "flag enum"-style pretty-printing to any enum.
2055 ** gdb.lookup_symbol can now work when there is no current frame.
2057 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2058 the source at which the symbol was defined.
2060 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2061 method 'value'. The former indicates whether the symbol needs a
2062 frame in order to compute its value, and the latter computes the
2065 ** A new method 'referenced_value' on gdb.Value objects which can
2066 dereference pointer as well as C++ reference values.
2068 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2069 which return the global and static blocks (as gdb.Block objects),
2070 of the underlying symbol table, respectively.
2072 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2073 object associated with a PC value.
2075 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2076 of the address range occupied by code for the current source line.
2078 * Go language support.
2079 GDB now supports debugging programs written in the Go programming
2082 * GDBserver now supports stdio connections.
2083 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2085 * The binary "gdbtui" can no longer be built or installed.
2086 Use "gdb -tui" instead.
2088 * GDB will now print "flag" enums specially. A flag enum is one where
2089 all the enumerator values have no bits in common when pairwise
2090 "and"ed. When printing a value whose type is a flag enum, GDB will
2091 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2092 (gdb) print (enum E) 3
2095 * The filename part of a linespec will now match trailing components
2096 of a source file name. For example, "break gcc/expr.c:1000" will
2097 now set a breakpoint in build/gcc/expr.c, but not
2098 build/libcpp/expr.c.
2100 * The "info proc" and "generate-core-file" commands will now also
2101 work on remote targets connected to GDBserver on Linux.
2103 * The command "info catch" has been removed. It has been disabled
2104 since December 2007.
2106 * The "catch exception" and "catch assert" commands now accept
2107 a condition at the end of the command, much like the "break"
2108 command does. For instance:
2110 (gdb) catch exception Constraint_Error if Barrier = True
2112 Previously, it was possible to add a condition to such catchpoints,
2113 but it had to be done as a second step, after the catchpoint had been
2114 created, using the "condition" command.
2116 * The "info static-tracepoint-marker" command will now also work on
2117 native Linux targets with in-process agent.
2119 * GDB can now set breakpoints on inlined functions.
2121 * The .gdb_index section has been updated to include symbols for
2122 inlined functions. GDB will ignore older .gdb_index sections by
2123 default, which could cause symbol files to be loaded more slowly
2124 until their .gdb_index sections can be recreated. The new command
2125 "set use-deprecated-index-sections on" will cause GDB to use any older
2126 .gdb_index sections it finds. This will restore performance, but the
2127 ability to set breakpoints on inlined functions will be lost in symbol
2128 files with older .gdb_index sections.
2130 The .gdb_index section has also been updated to record more information
2131 about each symbol. This speeds up the "info variables", "info functions"
2132 and "info types" commands when used with programs having the .gdb_index
2133 section, as well as speeding up debugging with shared libraries using
2134 the .gdb_index section.
2136 * Ada support for GDB/MI Variable Objects has been added.
2138 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2143 ** New command -info-os is the MI equivalent of "info os".
2145 ** Output logs ("set logging" and related) now include MI output.
2149 ** "set use-deprecated-index-sections on|off"
2150 "show use-deprecated-index-sections on|off"
2151 Controls the use of deprecated .gdb_index sections.
2153 ** "catch load" and "catch unload" can be used to stop when a shared
2154 library is loaded or unloaded, respectively.
2156 ** "enable count" can be used to auto-disable a breakpoint after
2159 ** "info vtbl" can be used to show the virtual method tables for
2160 C++ and Java objects.
2162 ** "explore" and its sub commands "explore value" and "explore type"
2163 can be used to recursively explore values and types of
2164 expressions. These commands are available only if GDB is
2165 configured with '--with-python'.
2167 ** "info auto-load" shows status of all kinds of auto-loaded files,
2168 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2169 sequences of commands files, "info auto-load python-scripts"
2170 shows status of auto-loading Python script files,
2171 "info auto-load local-gdbinit" shows status of loading init file
2172 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2173 status of inferior specific thread debugging shared library loading.
2175 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2176 and "show auto-load-scripts" commands have been deprecated, use their
2177 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2178 and "show auto-load python-scripts" counterparts instead.
2180 ** "dprintf location,format,args..." creates a dynamic printf, which
2181 is basically a breakpoint that does a printf and immediately
2182 resumes your program's execution, so it is like a printf that you
2183 can insert dynamically at runtime instead of at compiletime.
2185 ** "set print symbol"
2187 Controls whether GDB attempts to display the symbol, if any,
2188 corresponding to addresses it prints. This defaults to "on", but
2189 you can set it to "off" to restore GDB's previous behavior.
2191 * Deprecated commands
2193 ** For the Renesas Super-H architecture, the "regs" command has been
2194 deprecated, and "info all-registers" should be used instead.
2198 Renesas RL78 rl78-*-elf
2199 HP OpenVMS ia64 ia64-hp-openvms*
2201 * GDBserver supports evaluation of breakpoint conditions. When
2202 support is advertised by GDBserver, GDB may be told to send the
2203 breakpoint conditions in bytecode form to GDBserver. GDBserver
2204 will only report the breakpoint trigger to GDB when its condition
2209 set mips compression
2210 show mips compression
2211 Select the compressed ISA encoding used in functions that have no symbol
2212 information available. The encoding can be set to either of:
2215 and is updated automatically from ELF file flags if available.
2217 set breakpoint condition-evaluation
2218 show breakpoint condition-evaluation
2219 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2220 GDBserver ("target"). Default option "auto" chooses the most efficient
2222 This option can improve debugger efficiency depending on the speed of the
2226 Disable auto-loading globally.
2229 Show auto-loading setting of all kinds of auto-loaded files.
2231 set auto-load gdb-scripts on|off
2232 show auto-load gdb-scripts
2233 Control auto-loading of GDB canned sequences of commands files.
2235 set auto-load python-scripts on|off
2236 show auto-load python-scripts
2237 Control auto-loading of Python script files.
2239 set auto-load local-gdbinit on|off
2240 show auto-load local-gdbinit
2241 Control loading of init file (.gdbinit) from current directory.
2243 set auto-load libthread-db on|off
2244 show auto-load libthread-db
2245 Control auto-loading of inferior specific thread debugging shared library.
2247 set auto-load scripts-directory <dir1>[:<dir2>...]
2248 show auto-load scripts-directory
2249 Set a list of directories from which to load auto-loaded scripts.
2250 Automatically loaded Python scripts and GDB scripts are located in one
2251 of the directories listed by this option.
2252 The delimiter (':' above) may differ according to the host platform.
2254 set auto-load safe-path <dir1>[:<dir2>...]
2255 show auto-load safe-path
2256 Set a list of directories from which it is safe to auto-load files.
2257 The delimiter (':' above) may differ according to the host platform.
2259 set debug auto-load on|off
2260 show debug auto-load
2261 Control display of debugging info for auto-loading the files above.
2263 set dprintf-style gdb|call|agent
2265 Control the way in which a dynamic printf is performed; "gdb"
2266 requests a GDB printf command, while "call" causes dprintf to call a
2267 function in the inferior. "agent" requests that the target agent
2268 (such as GDBserver) do the printing.
2270 set dprintf-function <expr>
2271 show dprintf-function
2272 set dprintf-channel <expr>
2273 show dprintf-channel
2274 Set the function and optional first argument to the call when using
2275 the "call" style of dynamic printf.
2277 set disconnected-dprintf on|off
2278 show disconnected-dprintf
2279 Control whether agent-style dynamic printfs continue to be in effect
2280 after GDB disconnects.
2282 * New configure options
2284 --with-auto-load-dir
2285 Configure default value for the 'set auto-load scripts-directory'
2286 setting above. It defaults to '$debugdir:$datadir/auto-load',
2287 $debugdir representing global debugging info directories (available
2288 via 'show debug-file-directory') and $datadir representing GDB's data
2289 directory (available via 'show data-directory').
2291 --with-auto-load-safe-path
2292 Configure default value for the 'set auto-load safe-path' setting
2293 above. It defaults to the --with-auto-load-dir setting.
2295 --without-auto-load-safe-path
2296 Set 'set auto-load safe-path' to '/', effectively disabling this
2299 * New remote packets
2301 z0/z1 conditional breakpoints extension
2303 The z0/z1 breakpoint insertion packets have been extended to carry
2304 a list of conditional expressions over to the remote stub depending on the
2305 condition evaluation mode. The use of this extension can be controlled
2306 via the "set remote conditional-breakpoints-packet" command.
2310 Specify the signals which the remote stub may pass to the debugged
2311 program without GDB involvement.
2313 * New command line options
2315 --init-command=FILE, -ix Like --command, -x but execute it
2316 before loading inferior.
2317 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2318 execute it before loading inferior.
2320 *** Changes in GDB 7.4
2322 * GDB now handles ambiguous linespecs more consistently; the existing
2323 FILE:LINE support has been expanded to other types of linespecs. A
2324 breakpoint will now be set on all matching locations in all
2325 inferiors, and locations will be added or removed according to
2328 * GDB now allows you to skip uninteresting functions and files when
2329 stepping with the "skip function" and "skip file" commands.
2331 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2332 and "show remote hardware-watchpoint-length-limit". These allows to
2333 set or show the maximum length limit (in bytes) of a remote
2334 target hardware watchpoint.
2336 This allows e.g. to use "unlimited" hardware watchpoints with the
2337 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2338 watchpoints are slower than real hardware watchpoints but are
2339 significantly faster than gdb software watchpoints.
2343 ** The register_pretty_printer function in module gdb.printing now takes
2344 an optional `replace' argument. If True, the new printer replaces any
2347 ** The "maint set python print-stack on|off" command has been
2348 deprecated and will be deleted in GDB 7.5.
2349 A new command: "set python print-stack none|full|message" has
2350 replaced it. Additionally, the default for "print-stack" is
2351 now "message", which just prints the error message without
2354 ** A prompt substitution hook (prompt_hook) is now available to the
2357 ** A new Python module, gdb.prompt has been added to the GDB Python
2358 modules library. This module provides functionality for
2359 escape sequences in prompts (used by set/show
2360 extended-prompt). These escape sequences are replaced by their
2361 corresponding value.
2363 ** Python commands and convenience-functions located in
2364 'data-directory'/python/gdb/command and
2365 'data-directory'/python/gdb/function are now automatically loaded
2368 ** Blocks now provide four new attributes. global_block and
2369 static_block will return the global and static blocks
2370 respectively. is_static and is_global are boolean attributes
2371 that indicate if the block is one of those two types.
2373 ** Symbols now provide the "type" attribute, the type of the symbol.
2375 ** The "gdb.breakpoint" function has been deprecated in favor of
2378 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2379 of a function. This class is based on the "finish" command
2380 available in the CLI.
2382 ** Type objects for struct and union types now allow access to
2383 the fields using standard Python dictionary (mapping) methods.
2384 For example, "some_type['myfield']" now works, as does
2385 "some_type.items()".
2387 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2390 ** A new function, "deep_items" has been added to the gdb.types
2391 module in the GDB Python modules library. This function returns
2392 an iterator over the fields of a struct or union type. Unlike
2393 the standard Python "iteritems" method, it will recursively traverse
2394 any anonymous fields.
2398 ** "*stopped" events can report several new "reason"s, such as
2401 ** Breakpoint changes are now notified using new async records, like
2402 "=breakpoint-modified".
2404 ** New command -ada-task-info.
2406 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2407 $sdir specifies the default system locations of shared libraries.
2408 $pdir specifies the directory where the libpthread used by the application
2411 GDB no longer looks in $sdir and $pdir after it has searched the directories
2412 mentioned in libthread-db-search-path. If you want to search those
2413 directories, they must be specified in libthread-db-search-path.
2414 The default value of libthread-db-search-path on GNU/Linux and Solaris
2415 systems is now "$sdir:$pdir".
2417 $pdir is not supported by gdbserver, it is currently ignored.
2418 $sdir is supported by gdbserver.
2420 * New configure option --with-iconv-bin.
2421 When using the internationalization support like the one in the GNU C
2422 library, GDB will invoke the "iconv" program to get a list of supported
2423 character sets. If this program lives in a non-standard location, one can
2424 use this option to specify where to find it.
2426 * When natively debugging programs on PowerPC BookE processors running
2427 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2428 watchpoints, which specify a mask in addition to an address to watch.
2429 The mask specifies that some bits of an address (the bits which are
2430 reset in the mask) should be ignored when matching the address accessed
2431 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2432 section in the user manual for more details.
2434 * The new option --once causes GDBserver to stop listening for connections once
2435 the first connection is made. The listening port used by GDBserver will
2436 become available after that.
2438 * New commands "info macros" and "alias" have been added.
2440 * New function parameters suffix @entry specifies value of function parameter
2441 at the time the function got called. Entry values are available only since
2447 "!" is now an alias of the "shell" command.
2448 Note that no space is needed between "!" and SHELL COMMAND.
2452 watch EXPRESSION mask MASK_VALUE
2453 The watch command now supports the mask argument which allows creation
2454 of masked watchpoints, if the current architecture supports this feature.
2456 info auto-load-scripts [REGEXP]
2457 This command was formerly named "maintenance print section-scripts".
2458 It is now generally useful and is no longer a maintenance-only command.
2460 info macro [-all] [--] MACRO
2461 The info macro command has new options `-all' and `--'. The first for
2462 printing all definitions of a macro. The second for explicitly specifying
2463 the end of arguments and the beginning of the macro name in case the macro
2464 name starts with a hyphen.
2466 collect[/s] EXPRESSIONS
2467 The tracepoint collect command now takes an optional modifier "/s"
2468 that directs it to dereference pointer-to-character types and
2469 collect the bytes of memory up to a zero byte. The behavior is
2470 similar to what you see when you use the regular print command on a
2471 string. An optional integer following the "/s" sets a bound on the
2472 number of bytes that will be collected.
2475 The trace start command now interprets any supplied arguments as a
2476 note to be recorded with the trace run, with an effect similar to
2477 setting the variable trace-notes.
2480 The trace stop command now interprets any arguments as a note to be
2481 mentioned along with the tstatus report that the trace was stopped
2482 with a command. The effect is similar to setting the variable
2485 * Tracepoints can now be enabled and disabled at any time after a trace
2486 experiment has been started using the standard "enable" and "disable"
2487 commands. It is now possible to start a trace experiment with no enabled
2488 tracepoints; GDB will display a warning, but will allow the experiment to
2489 begin, assuming that tracepoints will be enabled as needed while the trace
2492 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2493 locations with 4-byte instructions, when they were previously
2494 limited to locations with instructions of 5 bytes or longer.
2498 set debug dwarf2-read
2499 show debug dwarf2-read
2500 Turns on or off display of debugging messages related to reading
2501 DWARF debug info. The default is off.
2503 set debug symtab-create
2504 show debug symtab-create
2505 Turns on or off display of debugging messages related to symbol table
2506 creation. The default is off.
2509 show extended-prompt
2510 Set the GDB prompt, and allow escape sequences to be inserted to
2511 display miscellaneous information (see 'help set extended-prompt'
2512 for the list of sequences). This prompt (and any information
2513 accessed through the escape sequences) is updated every time the
2514 prompt is displayed.
2516 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2517 show print entry-values
2518 Set printing of frame argument values at function entry. In some cases
2519 GDB can determine the value of function argument which was passed by the
2520 function caller, even if the value was modified inside the called function.
2522 set debug entry-values
2523 show debug entry-values
2524 Control display of debugging info for determining frame argument values at
2525 function entry and virtual tail call frames.
2527 set basenames-may-differ
2528 show basenames-may-differ
2529 Set whether a source file may have multiple base names.
2530 (A "base name" is the name of a file with the directory part removed.
2531 Example: The base name of "/home/user/hello.c" is "hello.c".)
2532 If set, GDB will canonicalize file names (e.g., expand symlinks)
2533 before comparing them. Canonicalization is an expensive operation,
2534 but it allows the same file be known by more than one base name.
2535 If not set (the default), all source files are assumed to have just
2536 one base name, and gdb will do file name comparisons more efficiently.
2542 Set a user name and notes for the current and any future trace runs.
2543 This is useful for long-running and/or disconnected traces, to
2544 inform others (or yourself) as to who is running the trace, supply
2545 contact information, or otherwise explain what is going on.
2547 set trace-stop-notes
2548 show trace-stop-notes
2549 Set a note attached to the trace run, that is displayed when the
2550 trace has been stopped by a tstop command. This is useful for
2551 instance as an explanation, if you are stopping a trace run that was
2552 started by someone else.
2554 * New remote packets
2558 Dynamically enable a tracepoint in a started trace experiment.
2562 Dynamically disable a tracepoint in a started trace experiment.
2566 Set the user and notes of the trace run.
2570 Query the current status of a tracepoint.
2574 Query the minimum length of instruction at which a fast tracepoint may
2577 * Dcache size (number of lines) and line-size are now runtime-configurable
2578 via "set dcache line" and "set dcache line-size" commands.
2582 Texas Instruments TMS320C6x tic6x-*-*
2586 Renesas RL78 rl78-*-elf
2588 *** Changes in GDB 7.3.1
2590 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2592 *** Changes in GDB 7.3
2594 * GDB has a new command: "thread find [REGEXP]".
2595 It finds the thread id whose name, target id, or thread extra info
2596 matches the given regular expression.
2598 * The "catch syscall" command now works on mips*-linux* targets.
2600 * The -data-disassemble MI command now supports modes 2 and 3 for
2601 dumping the instruction opcodes.
2603 * New command line options
2605 -data-directory DIR Specify DIR as the "data-directory".
2606 This is mostly for testing purposes.
2608 * The "maint set python auto-load on|off" command has been renamed to
2609 "set auto-load-scripts on|off".
2611 * GDB has a new command: "set directories".
2612 It is like the "dir" command except that it replaces the
2613 source path list instead of augmenting it.
2615 * GDB now understands thread names.
2617 On GNU/Linux, "info threads" will display the thread name as set by
2618 prctl or pthread_setname_np.
2620 There is also a new command, "thread name", which can be used to
2621 assign a name internally for GDB to display.
2624 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2625 has been integrated into GDB.
2629 ** The function gdb.Write now accepts an optional keyword 'stream'.
2630 This keyword, when provided, will direct the output to either
2631 stdout, stderr, or GDB's logging output.
2633 ** Parameters can now be be sub-classed in Python, and in particular
2634 you may implement the get_set_doc and get_show_doc functions.
2635 This improves how Parameter set/show documentation is processed
2636 and allows for more dynamic content.
2638 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2639 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2640 have an is_valid method.
2642 ** Breakpoints can now be sub-classed in Python, and in particular
2643 you may implement a 'stop' function that is executed each time
2644 the inferior reaches that breakpoint.
2646 ** New function gdb.lookup_global_symbol looks up a global symbol.
2648 ** GDB values in Python are now callable if the value represents a
2649 function. For example, if 'some_value' represents a function that
2650 takes two integer parameters and returns a value, you can call
2651 that function like so:
2653 result = some_value (10,20)
2655 ** Module gdb.types has been added.
2656 It contains a collection of utilities for working with gdb.Types objects:
2657 get_basic_type, has_field, make_enum_dict.
2659 ** Module gdb.printing has been added.
2660 It contains utilities for writing and registering pretty-printers.
2661 New classes: PrettyPrinter, SubPrettyPrinter,
2662 RegexpCollectionPrettyPrinter.
2663 New function: register_pretty_printer.
2665 ** New commands "info pretty-printers", "enable pretty-printer" and
2666 "disable pretty-printer" have been added.
2668 ** gdb.parameter("directories") is now available.
2670 ** New function gdb.newest_frame returns the newest frame in the
2673 ** The gdb.InferiorThread class has a new "name" attribute. This
2674 holds the thread's name.
2676 ** Python Support for Inferior events.
2677 Python scripts can add observers to be notified of events
2678 occurring in the process being debugged.
2679 The following events are currently supported:
2680 - gdb.events.cont Continue event.
2681 - gdb.events.exited Inferior exited event.
2682 - gdb.events.stop Signal received, and Breakpoint hit events.
2686 ** GDB now puts template parameters in scope when debugging in an
2687 instantiation. For example, if you have:
2689 template<int X> int func (void) { return X; }
2691 then if you step into func<5>, "print X" will show "5". This
2692 feature requires proper debuginfo support from the compiler; it
2693 was added to GCC 4.5.
2695 ** The motion commands "next", "finish", "until", and "advance" now
2696 work better when exceptions are thrown. In particular, GDB will
2697 no longer lose control of the inferior; instead, the GDB will
2698 stop the inferior at the point at which the exception is caught.
2699 This functionality requires a change in the exception handling
2700 code that was introduced in GCC 4.5.
2702 * GDB now follows GCC's rules on accessing volatile objects when
2703 reading or writing target state during expression evaluation.
2704 One notable difference to prior behavior is that "print x = 0"
2705 no longer generates a read of x; the value of the assignment is
2706 now always taken directly from the value being assigned.
2708 * GDB now has some support for using labels in the program's source in
2709 linespecs. For instance, you can use "advance label" to continue
2710 execution to a label.
2712 * GDB now has support for reading and writing a new .gdb_index
2713 section. This section holds a fast index of DWARF debugging
2714 information and can be used to greatly speed up GDB startup and
2715 operation. See the documentation for `save gdb-index' for details.
2717 * The "watch" command now accepts an optional "-location" argument.
2718 When used, this causes GDB to watch the memory referred to by the
2719 expression. Such a watchpoint is never deleted due to it going out
2722 * GDB now supports thread debugging of core dumps on GNU/Linux.
2724 GDB now activates thread debugging using the libthread_db library
2725 when debugging GNU/Linux core dumps, similarly to when debugging
2726 live processes. As a result, when debugging a core dump file, GDB
2727 is now able to display pthread_t ids of threads. For example, "info
2728 threads" shows the same output as when debugging the process when it
2729 was live. In earlier releases, you'd see something like this:
2732 * 1 LWP 6780 main () at main.c:10
2734 While now you see this:
2737 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2739 It is also now possible to inspect TLS variables when debugging core
2742 When debugging a core dump generated on a machine other than the one
2743 used to run GDB, you may need to point GDB at the correct
2744 libthread_db library with the "set libthread-db-search-path"
2745 command. See the user manual for more details on this command.
2747 * When natively debugging programs on PowerPC BookE processors running
2748 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2749 which stop execution of the inferior whenever it executes an instruction
2750 at any address within the specified range. See the "PowerPC Embedded"
2751 section in the user manual for more details.
2753 * New features in the GDB remote stub, GDBserver
2755 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2756 and i686 LynxOS (version 5.x).
2758 ** GDBserver is now supported on Blackfin Linux.
2760 * New native configurations
2762 ia64 HP-UX ia64-*-hpux*
2766 Analog Devices, Inc. Blackfin Processor bfin-*
2768 * Ada task switching is now supported on sparc-elf targets when
2769 debugging a program using the Ravenscar Profile. For more information,
2770 see the "Tasking Support when using the Ravenscar Profile" section
2771 in the GDB user manual.
2773 * Guile support was removed.
2775 * New features in the GNU simulator
2777 ** The --map-info flag lists all known core mappings.
2779 ** CFI flashes may be simulated via the "cfi" device.
2781 *** Changes in GDB 7.2
2783 * Shared library support for remote targets by default
2785 When GDB is configured for a generic, non-OS specific target, like
2786 for example, --target=arm-eabi or one of the many *-*-elf targets,
2787 GDB now queries remote stubs for loaded shared libraries using the
2788 `qXfer:libraries:read' packet. Previously, shared library support
2789 was always disabled for such configurations.
2793 ** Argument Dependent Lookup (ADL)
2795 In C++ ADL lookup directs function search to the namespaces of its
2796 arguments even if the namespace has not been imported.
2806 Here the compiler will search for `foo' in the namespace of 'b'
2807 and find A::foo. GDB now supports this. This construct is commonly
2808 used in the Standard Template Library for operators.
2810 ** Improved User Defined Operator Support
2812 In addition to member operators, GDB now supports lookup of operators
2813 defined in a namespace and imported with a `using' directive, operators
2814 defined in the global scope, operators imported implicitly from an
2815 anonymous namespace, and the ADL operators mentioned in the previous
2817 GDB now also supports proper overload resolution for all the previously
2818 mentioned flavors of operators.
2820 ** static const class members
2822 Printing of static const class members that are initialized in the
2823 class definition has been fixed.
2825 * Windows Thread Information Block access.
2827 On Windows targets, GDB now supports displaying the Windows Thread
2828 Information Block (TIB) structure. This structure is visible either
2829 by using the new command `info w32 thread-information-block' or, by
2830 dereferencing the new convenience variable named `$_tlb', a
2831 thread-specific pointer to the TIB. This feature is also supported
2832 when remote debugging using GDBserver.
2834 * Static tracepoints
2836 Static tracepoints are calls in the user program into a tracing
2837 library. One such library is a port of the LTTng kernel tracer to
2838 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2839 When debugging with GDBserver, GDB now supports combining the GDB
2840 tracepoint machinery with such libraries. For example: the user can
2841 use GDB to probe a static tracepoint marker (a call from the user
2842 program into the tracing library) with the new "strace" command (see
2843 "New commands" below). This creates a "static tracepoint" in the
2844 breakpoint list, that can be manipulated with the same feature set
2845 as fast and regular tracepoints. E.g., collect registers, local and
2846 global variables, collect trace state variables, and define
2847 tracepoint conditions. In addition, the user can collect extra
2848 static tracepoint marker specific data, by collecting the new
2849 $_sdata internal variable. When analyzing the trace buffer, you can
2850 inspect $_sdata like any other variable available to GDB. For more
2851 information, see the "Tracepoints" chapter in GDB user manual. New
2852 remote packets have been defined to support static tracepoints, see
2853 the "New remote packets" section below.
2855 * Better reconstruction of tracepoints after disconnected tracing
2857 GDB will attempt to download the original source form of tracepoint
2858 definitions when starting a trace run, and then will upload these
2859 upon reconnection to the target, resulting in a more accurate
2860 reconstruction of the tracepoints that are in use on the target.
2864 You can now exercise direct control over the ways that GDB can
2865 affect your program. For instance, you can disallow the setting of
2866 breakpoints, so that the program can run continuously (assuming
2867 non-stop mode). In addition, the "observer" variable is available
2868 to switch all of the different controls; in observer mode, GDB
2869 cannot affect the target's behavior at all, which is useful for
2870 tasks like diagnosing live systems in the field.
2872 * The new convenience variable $_thread holds the number of the
2875 * New remote packets
2879 Return the address of the Windows Thread Information Block of a given thread.
2883 In response to several of the tracepoint packets, the target may now
2884 also respond with a number of intermediate `qRelocInsn' request
2885 packets before the final result packet, to have GDB handle
2886 relocating an instruction to execute at a different address. This
2887 is particularly useful for stubs that support fast tracepoints. GDB
2888 reports support for this feature in the qSupported packet.
2892 List static tracepoint markers in the target program.
2896 List static tracepoint markers at a given address in the target
2899 qXfer:statictrace:read
2901 Read the static trace data collected (by a `collect $_sdata'
2902 tracepoint action). The remote stub reports support for this packet
2903 to gdb's qSupported query.
2907 Send the current settings of GDB's permission flags.
2911 Send part of the source (textual) form of a tracepoint definition,
2912 which includes location, conditional, and action list.
2914 * The source command now accepts a -s option to force searching for the
2915 script in the source search path even if the script name specifies
2918 * New features in the GDB remote stub, GDBserver
2920 - GDBserver now support tracepoints (including fast tracepoints, and
2921 static tracepoints). The feature is currently supported by the
2922 i386-linux and amd64-linux builds. See the "Tracepoints support
2923 in gdbserver" section in the manual for more information.
2925 GDBserver JIT compiles the tracepoint's conditional agent
2926 expression bytecode into native code whenever possible for low
2927 overhead dynamic tracepoints conditionals. For such tracepoints,
2928 an expression that examines program state is evaluated when the
2929 tracepoint is reached, in order to determine whether to capture
2930 trace data. If the condition is simple and false, processing the
2931 tracepoint finishes very quickly and no data is gathered.
2933 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2934 for static tracepoints support.
2936 - GDBserver now supports x86_64 Windows 64-bit debugging.
2938 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2939 it understands register description.
2941 * The --batch flag now disables pagination and queries.
2943 * X86 general purpose registers
2945 GDB now supports reading/writing byte, word and double-word x86
2946 general purpose registers directly. This means you can use, say,
2947 $ah or $ax to refer, respectively, to the byte register AH and
2948 16-bit word register AX that are actually portions of the 32-bit
2949 register EAX or 64-bit register RAX.
2951 * The `commands' command now accepts a range of breakpoints to modify.
2952 A plain `commands' following a command that creates multiple
2953 breakpoints affects all the breakpoints set by that command. This
2954 applies to breakpoints set by `rbreak', and also applies when a
2955 single `break' command creates multiple breakpoints (e.g.,
2956 breakpoints on overloaded c++ functions).
2958 * The `rbreak' command now accepts a filename specification as part of
2959 its argument, limiting the functions selected by the regex to those
2960 in the specified file.
2962 * Support for remote debugging Windows and SymbianOS shared libraries
2963 from Unix hosts has been improved. Non Windows GDB builds now can
2964 understand target reported file names that follow MS-DOS based file
2965 system semantics, such as file names that include drive letters and
2966 use the backslash character as directory separator. This makes it
2967 possible to transparently use the "set sysroot" and "set
2968 solib-search-path" on Unix hosts to point as host copies of the
2969 target's shared libraries. See the new command "set
2970 target-file-system-kind" described below, and the "Commands to
2971 specify files" section in the user manual for more information.
2975 eval template, expressions...
2976 Convert the values of one or more expressions under the control
2977 of the string template to a command line, and call it.
2979 set target-file-system-kind unix|dos-based|auto
2980 show target-file-system-kind
2981 Set or show the assumed file system kind for target reported file
2984 save breakpoints <filename>
2985 Save all current breakpoint definitions to a file suitable for use
2986 in a later debugging session. To read the saved breakpoint
2987 definitions, use the `source' command.
2989 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2992 info static-tracepoint-markers
2993 Display information about static tracepoint markers in the target.
2995 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2996 Define a static tracepoint by probing a marker at the given
2997 function, line, address, or marker ID.
3001 Enable and disable observer mode.
3003 set may-write-registers on|off
3004 set may-write-memory on|off
3005 set may-insert-breakpoints on|off
3006 set may-insert-tracepoints on|off
3007 set may-insert-fast-tracepoints on|off
3008 set may-interrupt on|off
3009 Set individual permissions for GDB effects on the target. Note that
3010 some of these settings can have undesirable or surprising
3011 consequences, particularly when changed in the middle of a session.
3012 For instance, disabling the writing of memory can prevent
3013 breakpoints from being inserted, cause single-stepping to fail, or
3014 even crash your program, if you disable after breakpoints have been
3015 inserted. However, GDB should not crash.
3017 set record memory-query on|off
3018 show record memory-query
3019 Control whether to stop the inferior if memory changes caused
3020 by an instruction cannot be recorded.
3025 The disassemble command now supports "start,+length" form of two arguments.
3029 ** GDB now provides a new directory location, called the python directory,
3030 where Python scripts written for GDB can be installed. The location
3031 of that directory is <data-directory>/python, where <data-directory>
3032 is the GDB data directory. For more details, see section `Scripting
3033 GDB using Python' in the manual.
3035 ** The GDB Python API now has access to breakpoints, symbols, symbol
3036 tables, program spaces, inferiors, threads and frame's code blocks.
3037 Additionally, GDB Parameters can now be created from the API, and
3038 manipulated via set/show in the CLI.
3040 ** New functions gdb.target_charset, gdb.target_wide_charset,
3041 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3043 ** New exception gdb.GdbError.
3045 ** Pretty-printers are now also looked up in the current program space.
3047 ** Pretty-printers can now be individually enabled and disabled.
3049 ** GDB now looks for names of Python scripts to auto-load in a
3050 special section named `.debug_gdb_scripts', in addition to looking
3051 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3053 * Tracepoint actions were unified with breakpoint commands. In particular,
3054 there are no longer differences in "info break" output for breakpoints and
3055 tracepoints and the "commands" command can be used for both tracepoints and
3056 regular breakpoints.
3060 ARM Symbian arm*-*-symbianelf*
3062 * D language support.
3063 GDB now supports debugging programs written in the D programming
3066 * GDB now supports the extended ptrace interface for PowerPC which is
3067 available since Linux kernel version 2.6.34. This automatically enables
3068 any hardware breakpoints and additional hardware watchpoints available in
3069 the processor. The old ptrace interface exposes just one hardware
3070 watchpoint and no hardware breakpoints.
3072 * GDB is now able to use the Data Value Compare (DVC) register available on
3073 embedded PowerPC processors to implement in hardware simple watchpoint
3074 conditions of the form:
3076 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3078 This works in native GDB running on Linux kernels with the extended ptrace
3079 interface mentioned above.
3081 *** Changes in GDB 7.1
3085 ** Namespace Support
3087 GDB now supports importing of namespaces in C++. This enables the
3088 user to inspect variables from imported namespaces. Support for
3089 namepace aliasing has also been added. So, if a namespace is
3090 aliased in the current scope (e.g. namepace C=A; ) the user can
3091 print variables using the alias (e.g. (gdb) print C::x).
3095 All known bugs relating to the printing of virtual base class were
3096 fixed. It is now possible to call overloaded static methods using a
3101 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3102 and reinterpret_cast<> are now handled by the C++ expression parser.
3106 Xilinx MicroBlaze microblaze-*-*
3111 Xilinx MicroBlaze microblaze
3114 * Multi-program debugging.
3116 GDB now has support for multi-program (a.k.a. multi-executable or
3117 multi-exec) debugging. This allows for debugging multiple inferiors
3118 simultaneously each running a different program under the same GDB
3119 session. See "Debugging Multiple Inferiors and Programs" in the
3120 manual for more information. This implied some user visible changes
3121 in the multi-inferior support. For example, "info inferiors" now
3122 lists inferiors that are not running yet or that have exited
3123 already. See also "New commands" and "New options" below.
3125 * New tracing features
3127 GDB's tracepoint facility now includes several new features:
3129 ** Trace state variables
3131 GDB tracepoints now include support for trace state variables, which
3132 are variables managed by the target agent during a tracing
3133 experiment. They are useful for tracepoints that trigger each
3134 other, so for instance one tracepoint can count hits in a variable,
3135 and then a second tracepoint has a condition that is true when the
3136 count reaches a particular value. Trace state variables share the
3137 $-syntax of GDB convenience variables, and can appear in both
3138 tracepoint actions and condition expressions. Use the "tvariable"
3139 command to create, and "info tvariables" to view; see "Trace State
3140 Variables" in the manual for more detail.
3144 GDB now includes an option for defining fast tracepoints, which
3145 targets may implement more efficiently, such as by installing a jump
3146 into the target agent rather than a trap instruction. The resulting
3147 speedup can be by two orders of magnitude or more, although the
3148 tradeoff is that some program locations on some target architectures
3149 might not allow fast tracepoint installation, for instance if the
3150 instruction to be replaced is shorter than the jump. To request a
3151 fast tracepoint, use the "ftrace" command, with syntax identical to
3152 the regular trace command.
3154 ** Disconnected tracing
3156 It is now possible to detach GDB from the target while it is running
3157 a trace experiment, then reconnect later to see how the experiment
3158 is going. In addition, a new variable disconnected-tracing lets you
3159 tell the target agent whether to continue running a trace if the
3160 connection is lost unexpectedly.
3164 GDB now has the ability to save the trace buffer into a file, and
3165 then use that file as a target, similarly to you can do with
3166 corefiles. You can select trace frames, print data that was
3167 collected in them, and use tstatus to display the state of the
3168 tracing run at the moment that it was saved. To create a trace
3169 file, use "tsave <filename>", and to use it, do "target tfile
3172 ** Circular trace buffer
3174 You can ask the target agent to handle the trace buffer as a
3175 circular buffer, discarding the oldest trace frames to make room for
3176 newer ones, by setting circular-trace-buffer to on. This feature may
3177 not be available for all target agents.
3182 The disassemble command, when invoked with two arguments, now requires
3183 the arguments to be comma-separated.
3186 The info variables command now displays variable definitions. Files
3187 which only declare a variable are not shown.
3190 The source command is now capable of sourcing Python scripts.
3191 This feature is dependent on the debugger being build with Python
3194 Related to this enhancement is also the introduction of a new command
3195 "set script-extension" (see below).
3197 * New commands (for set/show, see "New options" below)
3199 record save [<FILENAME>]
3200 Save a file (in core file format) containing the process record
3201 execution log for replay debugging at a later time.
3203 record restore <FILENAME>
3204 Restore the process record execution log that was saved at an
3205 earlier time, for replay debugging.
3207 add-inferior [-copies <N>] [-exec <FILENAME>]
3210 clone-inferior [-copies <N>] [ID]
3211 Make a new inferior ready to execute the same program another
3212 inferior has loaded.
3217 maint info program-spaces
3218 List the program spaces loaded into GDB.
3220 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3221 show remote interrupt-sequence
3222 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3223 as the sequence to the remote target in order to interrupt the execution.
3224 Ctrl-C is a default. Some system prefers BREAK which is high level of
3225 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3226 Magic SysRq g. It is BREAK signal and character 'g'.
3228 set remote interrupt-on-connect [on | off]
3229 show remote interrupt-on-connect
3230 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3231 remote target when gdb connects to it. This is needed when you debug
3234 set remotebreak [on | off]
3236 Deprecated. Use "set/show remote interrupt-sequence" instead.
3238 tvariable $NAME [ = EXP ]
3239 Create or modify a trace state variable.
3242 List trace state variables and their values.
3244 delete tvariable $NAME ...
3245 Delete one or more trace state variables.
3248 Evaluate the given expressions without collecting anything into the
3249 trace buffer. (Valid in tracepoint actions only.)
3251 ftrace FN / FILE:LINE / *ADDR
3252 Define a fast tracepoint at the given function, line, or address.
3254 * New expression syntax
3256 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3257 GDB now parses 0b101010 identically with 42.
3261 set follow-exec-mode new|same
3262 show follow-exec-mode
3263 Control whether GDB reuses the same inferior across an exec call or
3264 creates a new one. This is useful to be able to restart the old
3265 executable after the inferior having done an exec call.
3267 set default-collect EXPR, ...
3268 show default-collect
3269 Define a list of expressions to be collected at each tracepoint.
3270 This is a useful way to ensure essential items are not overlooked,
3271 such as registers or a critical global variable.
3273 set disconnected-tracing
3274 show disconnected-tracing
3275 If set to 1, the target is instructed to continue tracing if it
3276 loses its connection to GDB. If 0, the target is to stop tracing
3279 set circular-trace-buffer
3280 show circular-trace-buffer
3281 If set to on, the target is instructed to use a circular trace buffer
3282 and discard the oldest trace frames instead of stopping the trace due
3283 to a full trace buffer. If set to off, the trace stops when the buffer
3284 fills up. Some targets may not support this.
3286 set script-extension off|soft|strict
3287 show script-extension
3288 If set to "off", the debugger does not perform any script language
3289 recognition, and all sourced files are assumed to be GDB scripts.
3290 If set to "soft" (the default), files are sourced according to
3291 filename extension, falling back to GDB scripts if the first
3293 If set to "strict", files are sourced according to filename extension.
3295 set ada trust-PAD-over-XVS on|off
3296 show ada trust-PAD-over-XVS
3297 If off, activate a workaround against a bug in the debugging information
3298 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3299 the GCC sources for more information about the GNAT encoding and
3300 PAD types in particular). It is always safe to set this option to
3301 off, but this introduces a slight performance penalty. The default
3304 * Python API Improvements
3306 ** GDB provides the new class gdb.LazyString. This is useful in
3307 some pretty-printing cases. The new method gdb.Value.lazy_string
3308 provides a simple way to create objects of this type.
3310 ** The fields returned by gdb.Type.fields now have an
3311 `is_base_class' attribute.
3313 ** The new method gdb.Type.range returns the range of an array type.
3315 ** The new method gdb.parse_and_eval can be used to parse and
3316 evaluate an expression.
3318 * New remote packets
3321 Define a trace state variable.
3324 Get the current value of a trace state variable.
3327 Set desired tracing behavior upon disconnection.
3330 Set the trace buffer to be linear or circular.
3333 Get data about the tracepoints currently in use.
3337 Process record now works correctly with hardware watchpoints.
3339 Multiple bug fixes have been made to the mips-irix port, making it
3340 much more reliable. In particular:
3341 - Debugging threaded applications is now possible again. Previously,
3342 GDB would hang while starting the program, or while waiting for
3343 the program to stop at a breakpoint.
3344 - Attaching to a running process no longer hangs.
3345 - An error occurring while loading a core file has been fixed.
3346 - Changing the value of the PC register now works again. This fixes
3347 problems observed when using the "jump" command, or when calling
3348 a function from GDB, or even when assigning a new value to $pc.
3349 - With the "finish" and "return" commands, the return value for functions
3350 returning a small array is now correctly printed.
3351 - It is now possible to break on shared library code which gets executed
3352 during a shared library init phase (code executed while executing
3353 their .init section). Previously, the breakpoint would have no effect.
3354 - GDB is now able to backtrace through the signal handler for
3355 non-threaded programs.
3357 PIE (Position Independent Executable) programs debugging is now supported.
3358 This includes debugging execution of PIC (Position Independent Code) shared
3359 libraries although for that, it should be possible to run such libraries as an
3362 *** Changes in GDB 7.0
3364 * GDB now has an interface for JIT compilation. Applications that
3365 dynamically generate code can create symbol files in memory and register
3366 them with GDB. For users, the feature should work transparently, and
3367 for JIT developers, the interface is documented in the GDB manual in the
3368 "JIT Compilation Interface" chapter.
3370 * Tracepoints may now be conditional. The syntax is as for
3371 breakpoints; either an "if" clause appended to the "trace" command,
3372 or the "condition" command is available. GDB sends the condition to
3373 the target for evaluation using the same bytecode format as is used
3374 for tracepoint actions.
3376 * The disassemble command now supports: an optional /r modifier, print the
3377 raw instructions in hex as well as in symbolic form, and an optional /m
3378 modifier to print mixed source+assembly.
3380 * Process record and replay
3382 In a architecture environment that supports ``process record and
3383 replay'', ``process record and replay'' target can record a log of
3384 the process execution, and replay it with both forward and reverse
3387 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3388 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3389 set execution-direction {forward|reverse}, for targets that support
3392 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3393 feature is available with a native GDB running on kernel version
3396 * GDB now has support for multi-byte and wide character sets on the
3397 target. Strings whose character type is wchar_t, char16_t, or
3398 char32_t are now correctly printed. GDB supports wide- and unicode-
3399 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3400 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3401 `printf'. This feature requires iconv to work properly; if your
3402 system does not have a working iconv, GDB can use GNU libiconv. See
3403 the installation instructions for more information.
3405 * GDB now supports automatic retrieval of shared library files from
3406 remote targets. To use this feature, specify a system root that begins
3407 with the `remote:' prefix, either via the `set sysroot' command or via
3408 the `--with-sysroot' configure-time option.
3410 * "info sharedlibrary" now takes an optional regex of libraries to show,
3411 and it now reports if a shared library has no debugging information.
3413 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3414 now complete on file names.
3416 * When completing in expressions, gdb will attempt to limit
3417 completions to allowable structure or union fields, where appropriate.
3418 For instance, consider:
3420 # struct example { int f1; double f2; };
3421 # struct example variable;
3424 If the user types TAB at the end of this command line, the available
3425 completions will be "f1" and "f2".
3427 * Inlined functions are now supported. They show up in backtraces, and
3428 the "step", "next", and "finish" commands handle them automatically.
3430 * GDB now supports the token-splicing (##) and stringification (#)
3431 operators when expanding macros. It also supports variable-arity
3434 * GDB now supports inspecting extra signal information, exported by
3435 the new $_siginfo convenience variable. The feature is currently
3436 implemented on linux ARM, i386 and amd64.
3438 * GDB can now display the VFP floating point registers and NEON vector
3439 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3440 can provide these registers (requires Linux 2.6.30 or later). Remote
3441 and simulator targets may also provide them.
3443 * New remote packets
3446 Search memory for a sequence of bytes.
3449 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3450 operation over reliable transport links. Use of this packet is
3451 controlled by the `set remote noack-packet' command.
3454 Kill the process with the specified process ID. Use this in preference
3455 to `k' when multiprocess protocol extensions are supported.
3458 Obtains additional operating system information
3462 Read or write additional signal information.
3464 * Removed remote protocol undocumented extension
3466 An undocumented extension to the remote protocol's `S' stop reply
3467 packet that permited the stub to pass a process id was removed.
3468 Remote servers should use the `T' stop reply packet instead.
3470 * GDB now supports multiple function calling conventions according to the
3471 DWARF-2 DW_AT_calling_convention function attribute.
3473 * The SH target utilizes the aforementioned change to distinguish between gcc
3474 and Renesas calling convention. It also adds the new CLI commands
3475 `set/show sh calling-convention'.
3477 * GDB can now read compressed debug sections, as produced by GNU gold
3478 with the --compress-debug-sections=zlib flag.
3480 * 64-bit core files are now supported on AIX.
3482 * Thread switching is now supported on Tru64.
3484 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3485 which will be allocated using malloc later in program execution.
3487 * The qXfer:libraries:read remote procotol packet now allows passing a
3488 list of section offsets.
3490 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3491 conditions handling signals delivered during attach or thread creation
3492 have also been fixed.
3494 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3495 From the user's standpoint, all unqualified instances of True and False
3496 are treated as the standard definitions, regardless of context.
3498 * GDB now parses C++ symbol and type names more flexibly. For
3501 template<typename T> class C { };
3504 GDB will now correctly handle all of:
3506 ptype C<char const *>
3507 ptype C<char const*>
3508 ptype C<const char *>
3509 ptype C<const char*>
3511 * New features in the GDB remote stub, gdbserver
3513 - The "--wrapper" command-line argument tells gdbserver to use a
3514 wrapper program to launch programs for debugging.
3516 - On PowerPC and S/390 targets, it is now possible to use a single
3517 gdbserver executable to debug both 32-bit and 64-bit programs.
3518 (This requires gdbserver itself to be built as a 64-bit executable.)
3520 - gdbserver uses the new noack protocol mode for TCP connections to
3521 reduce communications latency, if also supported and enabled in GDB.
3523 - Support for the sparc64-linux-gnu target is now included in
3526 - The amd64-linux build of gdbserver now supports debugging both
3527 32-bit and 64-bit programs.
3529 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3530 now support hardware watchpoints, and will use them automatically
3535 GDB now has support for scripting using Python. Whether this is
3536 available is determined at configure time.
3538 New GDB commands can now be written in Python.
3540 * Ada tasking support
3542 Ada tasks can now be inspected in GDB. The following commands have
3546 Print the list of Ada tasks.
3548 Print detailed information about task number N.
3550 Print the task number of the current task.
3552 Switch the context of debugging to task number N.
3554 * Support for user-defined prefixed commands. The "define" command can
3555 add new commands to existing prefixes, e.g. "target".
3557 * Multi-inferior, multi-process debugging.
3559 GDB now has generalized support for multi-inferior debugging. See
3560 "Debugging Multiple Inferiors" in the manual for more information.
3561 Although availability still depends on target support, the command
3562 set is more uniform now. The GNU/Linux specific multi-forks support
3563 has been migrated to this new framework. This implied some user
3564 visible changes; see "New commands" and also "Removed commands"
3567 * Target descriptions can now describe the target OS ABI. See the
3568 "Target Description Format" section in the user manual for more
3571 * Target descriptions can now describe "compatible" architectures
3572 to indicate that the target can execute applications for a different
3573 architecture in addition to those for the main target architecture.
3574 See the "Target Description Format" section in the user manual for
3577 * Multi-architecture debugging.
3579 GDB now includes general supports for debugging applications on
3580 hybrid systems that use more than one single processor architecture
3581 at the same time. Each such hybrid architecture still requires
3582 specific support to be added. The only hybrid architecture supported
3583 in this version of GDB is the Cell Broadband Engine.
3585 * GDB now supports integrated debugging of Cell/B.E. applications that
3586 use both the PPU and SPU architectures. To enable support for hybrid
3587 Cell/B.E. debugging, you need to configure GDB to support both the
3588 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3589 --enable-targets configure option.
3591 * Non-stop mode debugging.
3593 For some targets, GDB now supports an optional mode of operation in
3594 which you can examine stopped threads while other threads continue
3595 to execute freely. This is referred to as non-stop mode, with the
3596 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3597 section in the user manual for more information.
3599 To be able to support remote non-stop debugging, a remote stub needs
3600 to implement the non-stop mode remote protocol extensions, as
3601 described in the "Remote Non-Stop" section of the user manual. The
3602 GDB remote stub, gdbserver, has been adjusted to support these
3603 extensions on linux targets.
3605 * New commands (for set/show, see "New options" below)
3607 catch syscall [NAME(S) | NUMBER(S)]
3608 Catch system calls. Arguments, which should be names of system
3609 calls or their numbers, mean catch only those syscalls. Without
3610 arguments, every syscall will be caught. When the inferior issues
3611 any of the specified syscalls, GDB will stop and announce the system
3612 call, both when it is called and when its call returns. This
3613 feature is currently available with a native GDB running on the
3614 Linux Kernel, under the following architectures: x86, x86_64,
3615 PowerPC and PowerPC64.
3617 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3619 Search memory for a sequence of bytes.
3621 maint set python print-stack
3622 maint show python print-stack
3623 Show a stack trace when an error is encountered in a Python script.
3626 Invoke CODE by passing it to the Python interpreter.
3631 These allow macros to be defined, undefined, and listed
3635 Show operating system information about processes.
3638 List the inferiors currently under GDB's control.
3641 Switch focus to inferior number NUM.
3644 Detach from inferior number NUM.
3647 Kill inferior number NUM.
3651 set spu stop-on-load
3652 show spu stop-on-load
3653 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3655 set spu auto-flush-cache
3656 show spu auto-flush-cache
3657 Control whether to automatically flush the software-managed cache
3658 during Cell/B.E. debugging.
3660 set sh calling-convention
3661 show sh calling-convention
3662 Control the calling convention used when calling SH target functions.
3665 show debug timestamp
3666 Control display of timestamps with GDB debugging output.
3668 set disassemble-next-line
3669 show disassemble-next-line
3670 Control display of disassembled source lines or instructions when
3673 set remote noack-packet
3674 show remote noack-packet
3675 Set/show the use of remote protocol QStartNoAckMode packet. See above
3676 under "New remote packets."
3678 set remote query-attached-packet
3679 show remote query-attached-packet
3680 Control use of remote protocol `qAttached' (query-attached) packet.
3682 set remote read-siginfo-object
3683 show remote read-siginfo-object
3684 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3687 set remote write-siginfo-object
3688 show remote write-siginfo-object
3689 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3692 set remote reverse-continue
3693 show remote reverse-continue
3694 Control use of remote protocol 'bc' (reverse-continue) packet.
3696 set remote reverse-step
3697 show remote reverse-step
3698 Control use of remote protocol 'bs' (reverse-step) packet.
3700 set displaced-stepping
3701 show displaced-stepping
3702 Control displaced stepping mode. Displaced stepping is a way to
3703 single-step over breakpoints without removing them from the debuggee.
3704 Also known as "out-of-line single-stepping".
3707 show debug displaced
3708 Control display of debugging info for displaced stepping.
3710 maint set internal-error
3711 maint show internal-error
3712 Control what GDB does when an internal error is detected.
3714 maint set internal-warning
3715 maint show internal-warning
3716 Control what GDB does when an internal warning is detected.
3721 Use a wrapper program to launch programs for debugging.
3723 set multiple-symbols (all|ask|cancel)
3724 show multiple-symbols
3725 The value of this variable can be changed to adjust the debugger behavior
3726 when an expression or a breakpoint location contains an ambiguous symbol
3727 name (an overloaded function name, for instance).
3729 set breakpoint always-inserted
3730 show breakpoint always-inserted
3731 Keep breakpoints always inserted in the target, as opposed to inserting
3732 them when resuming the target, and removing them when the target stops.
3733 This option can improve debugger performance on slow remote targets.
3735 set arm fallback-mode (arm|thumb|auto)
3736 show arm fallback-mode
3737 set arm force-mode (arm|thumb|auto)
3739 These commands control how ARM GDB determines whether instructions
3740 are ARM or Thumb. The default for both settings is auto, which uses
3741 the current CPSR value for instructions without symbols; previous
3742 versions of GDB behaved as if "set arm fallback-mode arm".
3744 set disable-randomization
3745 show disable-randomization
3746 Standalone programs run with the virtual address space randomization enabled
3747 by default on some platforms. This option keeps the addresses stable across
3748 multiple debugging sessions.
3752 Control whether other threads are stopped or not when some thread hits
3757 Requests that asynchronous execution is enabled in the target, if available.
3758 In this case, it's possible to resume target in the background, and interact
3759 with GDB while the target is running. "show target-async" displays the
3760 current state of asynchronous execution of the target.
3762 set target-wide-charset
3763 show target-wide-charset
3764 The target-wide-charset is the name of the character set that GDB
3765 uses when printing characters whose type is wchar_t.
3767 set tcp auto-retry (on|off)
3769 set tcp connect-timeout
3770 show tcp connect-timeout
3771 These commands allow GDB to retry failed TCP connections to a remote stub
3772 with a specified timeout period; this is useful if the stub is launched
3773 in parallel with GDB but may not be ready to accept connections immediately.
3775 set libthread-db-search-path
3776 show libthread-db-search-path
3777 Control list of directories which GDB will search for appropriate
3780 set schedule-multiple (on|off)
3781 show schedule-multiple
3782 Allow GDB to resume all threads of all processes or only threads of
3783 the current process.
3787 Use more aggressive caching for accesses to the stack. This improves
3788 performance of remote debugging (particularly backtraces) without
3789 affecting correctness.
3791 set interactive-mode (on|off|auto)
3792 show interactive-mode
3793 Control whether GDB runs in interactive mode (on) or not (off).
3794 When in interactive mode, GDB waits for the user to answer all
3795 queries. Otherwise, GDB does not wait and assumes the default
3796 answer. When set to auto (the default), GDB determines which
3797 mode to use based on the stdin settings.
3802 For program forks, this is replaced by the new more generic `info
3803 inferiors' command. To list checkpoints, you can still use the
3804 `info checkpoints' command, which was an alias for the `info forks'
3808 Replaced by the new `inferior' command. To switch between
3809 checkpoints, you can still use the `restart' command, which was an
3810 alias for the `fork' command.
3813 This is removed, since some targets don't have a notion of
3814 processes. To switch between processes, you can still use the
3815 `inferior' command using GDB's own inferior number.
3818 For program forks, this is replaced by the new more generic `kill
3819 inferior' command. To delete a checkpoint, you can still use the
3820 `delete checkpoint' command, which was an alias for the `delete
3824 For program forks, this is replaced by the new more generic `detach
3825 inferior' command. To detach a checkpoint, you can still use the
3826 `detach checkpoint' command, which was an alias for the `detach
3829 * New native configurations
3831 x86/x86_64 Darwin i[34567]86-*-darwin*
3833 x86_64 MinGW x86_64-*-mingw*
3837 Lattice Mico32 lm32-*
3838 x86 DICOS i[34567]86-*-dicos*
3839 x86_64 DICOS x86_64-*-dicos*
3842 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3843 (mingw32ce) debugging.
3849 These commands were actually not implemented on any target.
3851 *** Changes in GDB 6.8
3853 * New native configurations
3855 NetBSD/hppa hppa*-*netbsd*
3856 Xtensa GNU/Linux xtensa*-*-linux*
3860 NetBSD/hppa hppa*-*-netbsd*
3861 Xtensa GNU/Lunux xtensa*-*-linux*
3863 * Change in command line behavior -- corefiles vs. process ids.
3865 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3866 attaching to process NUMBER fails, GDB no longer attempts to open a
3867 core file named NUMBER. Attaching to a program using the -c option
3868 is no longer supported. Instead, use the '-p' or '--pid' options.
3870 * GDB can now be built as a native debugger for debugging Windows x86
3871 (mingw32) Portable Executable (PE) programs.
3873 * Pending breakpoints no longer change their number when their address
3876 * GDB now supports breakpoints with multiple locations,
3877 including breakpoints on C++ constructors, inside C++ templates,
3878 and in inlined functions.
3880 * GDB's ability to debug optimized code has been improved. GDB more
3881 accurately identifies function bodies and lexical blocks that occupy
3882 more than one contiguous range of addresses.
3884 * Target descriptions can now describe registers for PowerPC.
3886 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3887 registers on PowerPC targets.
3889 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3890 targets even when the libthread_db library is not available.
3892 * The GDB remote stub, gdbserver, now supports the new file transfer
3893 commands (remote put, remote get, and remote delete).
3895 * The GDB remote stub, gdbserver, now supports run and attach in
3896 extended-remote mode.
3898 * hppa*64*-*-hpux11* target broken
3899 The debugger is unable to start a program and fails with the following
3900 error: "Error trying to get information about dynamic linker".
3901 The gdb-6.7 release is also affected.
3903 * GDB now supports the --enable-targets= configure option to allow
3904 building a single GDB executable that supports multiple remote
3905 target architectures.
3907 * GDB now supports debugging C and C++ programs which use the
3908 Decimal Floating Point extension. In addition, the PowerPC target
3909 now has a set of pseudo-registers to inspect decimal float values
3910 stored in two consecutive float registers.
3912 * The -break-insert MI command can optionally create pending
3915 * Improved support for debugging Ada
3916 Many improvements to the Ada language support have been made. These
3918 - Better support for Ada2005 interface types
3919 - Improved handling of arrays and slices in general
3920 - Better support for Taft-amendment types
3921 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3923 - Improved command completion in Ada
3926 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3931 set print frame-arguments (all|scalars|none)
3932 show print frame-arguments
3933 The value of this variable can be changed to control which argument
3934 values should be printed by the debugger when displaying a frame.
3939 Transfer files to and from a remote target, and delete remote files.
3946 Transfer files to and from a remote target, and delete remote files.
3948 * New remote packets
3955 Open, close, read, write, and delete files on the remote system.
3958 Attach to an existing process on the remote system, in extended-remote
3962 Run a new process on the remote system, in extended-remote mode.
3964 *** Changes in GDB 6.7
3966 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3967 bfd, libiberty and opcodes, as revealed by static analysis donated by
3968 Coverity, Inc. (http://scan.coverity.com).
3970 * When looking up multiply-defined global symbols, GDB will now prefer the
3971 symbol definition in the current shared library if it was built using the
3972 -Bsymbolic linker option.
3974 * When the Text User Interface (TUI) is not configured, GDB will now
3975 recognize the -tui command-line option and print a message that the TUI
3978 * The GDB remote stub, gdbserver, now has lower overhead for high
3979 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3981 * GDB for MIPS targets now autodetects whether a remote target provides
3982 32-bit or 64-bit register values.
3984 * Support for C++ member pointers has been improved.
3986 * GDB now understands XML target descriptions, which specify the
3987 target's overall architecture. GDB can read a description from
3988 a local file or over the remote serial protocol.
3990 * Vectors of single-byte data use a new integer type which is not
3991 automatically displayed as character or string data.
3993 * The /s format now works with the print command. It displays
3994 arrays of single-byte integers and pointers to single-byte integers
3997 * Target descriptions can now describe target-specific registers,
3998 for architectures which have implemented the support (currently
3999 only ARM, M68K, and MIPS).
4001 * GDB and the GDB remote stub, gdbserver, now support the XScale
4004 * The GDB remote stub, gdbserver, has been updated to support
4005 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4006 has been rewritten to use the standard GDB remote protocol.
4008 * GDB can now step into C++ functions which are called through thunks.
4010 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4012 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4013 layout. It also supports a TextSeg= and DataSeg= response when only
4014 segment base addresses (rather than offsets) are available.
4016 * The /i format now outputs any trailing branch delay slot instructions
4017 immediately following the last instruction within the count specified.
4019 * The GDB remote protocol "T" stop reply packet now supports a
4020 "library" response. Combined with the new "qXfer:libraries:read"
4021 packet, this response allows GDB to debug shared libraries on targets
4022 where the operating system manages the list of loaded libraries (e.g.
4023 Windows and SymbianOS).
4025 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4026 (DLLs) on Windows and Windows CE targets.
4028 * GDB now supports a faster verification that a .debug file matches its binary
4029 according to its build-id signature, if the signature is present.
4035 Enable or disable hardware flow control (RTS/CTS) on the serial port
4036 when debugging using remote targets.
4038 set mem inaccessible-by-default
4039 show mem inaccessible-by-default
4040 If the target supplies a memory map, for instance via the remote
4041 protocol's "qXfer:memory-map:read" packet, setting this variable
4042 prevents GDB from accessing memory outside the memory map. This
4043 is useful for targets with memory mapped registers or which react
4044 badly to accesses of unmapped address space.
4046 set breakpoint auto-hw
4047 show breakpoint auto-hw
4048 If the target supplies a memory map, for instance via the remote
4049 protocol's "qXfer:memory-map:read" packet, setting this variable
4050 lets GDB use hardware breakpoints automatically for memory regions
4051 where it can not use software breakpoints. This covers both the
4052 "break" command and internal breakpoints used for other commands
4053 including "next" and "finish".
4056 catch exception unhandled
4057 Stop the program execution when Ada exceptions are raised.
4060 Stop the program execution when an Ada assertion failed.
4064 Set an alternate system root for target files. This is a more
4065 general version of "set solib-absolute-prefix", which is now
4066 an alias to "set sysroot".
4069 Provide extended SPU facility status information. This set of
4070 commands is available only when debugging the Cell/B.E. SPU
4073 * New native configurations
4075 OpenBSD/sh sh*-*openbsd*
4078 unset tdesc filename
4080 Use the specified local file as an XML target description, and do
4081 not query the target for its built-in description.
4085 OpenBSD/sh sh*-*-openbsd*
4086 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4087 Toshiba Media Processor mep-elf
4089 * New remote packets
4092 Ignore the specified signals; pass them directly to the debugged program
4093 without stopping other threads or reporting them to GDB.
4095 qXfer:features:read:
4096 Read an XML target description from the target, which describes its
4101 Read or write contents of an spufs file on the target system. These
4102 packets are available only on the Cell/B.E. SPU architecture.
4104 qXfer:libraries:read:
4105 Report the loaded shared libraries. Combined with new "T" packet
4106 response, this packet allows GDB to debug shared libraries on
4107 targets where the operating system manages the list of loaded
4108 libraries (e.g. Windows and SymbianOS).
4112 Support for these obsolete configurations has been removed.
4120 i[34567]86-*-lynxos*
4121 i[34567]86-*-netware*
4122 i[34567]86-*-sco3.2v5*
4123 i[34567]86-*-sco3.2v4*
4125 i[34567]86-*-sysv4.2*
4128 i[34567]86-*-unixware2*
4129 i[34567]86-*-unixware*
4138 * Other removed features
4145 Various m68k-only ROM monitors.
4152 Various Renesas ROM monitors and debugging interfaces for SH and
4157 Support for a Macraigor serial interface to on-chip debugging.
4158 GDB does not directly support the newer parallel or USB
4163 A debug information format. The predecessor to DWARF 2 and
4164 DWARF 3, which are still supported.
4166 Support for the HP aCC compiler on HP-UX/PA-RISC
4168 SOM-encapsulated symbolic debugging information, automatic
4169 invocation of pxdb, and the aCC custom C++ ABI. This does not
4170 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4171 with aCC can still be debugged on an assembly level.
4173 MIPS ".pdr" sections
4175 A MIPS-specific format used to describe stack frame layout
4176 in debugging information.
4180 GDB could work with an older version of Guile to debug
4181 the interpreter and Scheme programs running in it.
4183 set mips stack-arg-size
4184 set mips saved-gpreg-size
4186 Use "set mips abi" to control parameter passing for MIPS.
4188 *** Changes in GDB 6.6
4193 Cell Broadband Engine SPU spu-elf
4195 * GDB can now be configured as a cross-debugger targeting native Windows
4196 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4197 running on a Windows system over TCP/IP to debug Windows programs.
4199 * The GDB remote stub, gdbserver, has been updated to support Windows and
4200 Cygwin debugging. Both single-threaded and multi-threaded programs are
4203 * The "set trust-readonly-sections" command works again. This command was
4204 broken in GDB 6.3, 6.4, and 6.5.
4206 * The "load" command now supports writing to flash memory, if the remote
4207 stub provides the required support.
4209 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4210 longer requires symbolic debug information (e.g. DWARF-2).
4215 unset substitute-path
4216 show substitute-path
4217 Manage a list of substitution rules that GDB uses to rewrite the name
4218 of the directories where the sources are located. This can be useful
4219 for instance when the sources were moved to a different location
4220 between compilation and debugging.
4224 Print each CLI command as it is executed. Each command is prefixed with
4225 a number of `+' symbols representing the nesting depth.
4226 The source command now has a `-v' option to enable the same feature.
4230 The ARM Demon monitor support (RDP protocol, "target rdp").
4232 Kernel Object Display, an embedded debugging feature which only worked with
4233 an obsolete version of Cisco IOS.
4235 The 'set download-write-size' and 'show download-write-size' commands.
4237 * New remote packets
4240 Tell a stub about GDB client features, and request remote target features.
4241 The first feature implemented is PacketSize, which allows the target to
4242 specify the size of packets it can handle - to minimize the number of
4243 packets required and improve performance when connected to a remote
4247 Fetch an OS auxilliary vector from the remote stub. This packet is a
4248 more efficient replacement for qPart:auxv:read.
4250 qXfer:memory-map:read:
4251 Fetch a memory map from the remote stub, including information about
4252 RAM, ROM, and flash memory devices.
4257 Erase and program a flash memory device.
4259 * Removed remote packets
4262 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4263 used it, and only gdbserver implemented it.
4265 *** Changes in GDB 6.5
4269 Renesas M32C/M16C m32c-elf
4271 Morpho Technologies ms1 ms1-elf
4275 init-if-undefined Initialize a convenience variable, but
4276 only if it doesn't already have a value.
4278 The following commands are presently only implemented for native GNU/Linux:
4280 checkpoint Save a snapshot of the program state.
4282 restart <n> Return the program state to a
4283 previously saved state.
4285 info checkpoints List currently saved checkpoints.
4287 delete-checkpoint <n> Delete a previously saved checkpoint.
4289 set|show detach-on-fork Tell gdb whether to detach from a newly
4290 forked process, or to keep debugging it.
4292 info forks List forks of the user program that
4293 are available to be debugged.
4295 fork <n> Switch to debugging one of several
4296 forks of the user program that are
4297 available to be debugged.
4299 delete-fork <n> Delete a fork from the list of forks
4300 that are available to be debugged (and
4301 kill the forked process).
4303 detach-fork <n> Delete a fork from the list of forks
4304 that are available to be debugged (and
4305 allow the process to continue).
4309 Morpho Technologies ms2 ms1-elf
4311 * Improved Windows host support
4313 GDB now builds as a cross debugger hosted on i686-mingw32, including
4314 native console support, and remote communications using either
4315 network sockets or serial ports.
4317 * Improved Modula-2 language support
4319 GDB can now print most types in the Modula-2 syntax. This includes:
4320 basic types, set types, record types, enumerated types, range types,
4321 pointer types and ARRAY types. Procedure var parameters are correctly
4322 printed and hexadecimal addresses and character constants are also
4323 written in the Modula-2 syntax. Best results can be obtained by using
4324 GNU Modula-2 together with the -gdwarf-2 command line option.
4328 The ARM rdi-share module.
4330 The Netware NLM debug server.
4332 *** Changes in GDB 6.4
4334 * New native configurations
4336 OpenBSD/arm arm*-*-openbsd*
4337 OpenBSD/mips64 mips64-*-openbsd*
4341 Morpho Technologies ms1 ms1-elf
4343 * New command line options
4345 --batch-silent As for --batch, but totally silent.
4346 --return-child-result The debugger will exist with the same value
4347 the child (debugged) program exited with.
4348 --eval-command COMMAND, -ex COMMAND
4349 Execute a single GDB CLI command. This may be
4350 specified multiple times and in conjunction
4351 with the --command (-x) option.
4353 * Deprecated commands removed
4355 The following commands, that were deprecated in 2000, have been
4359 set|show arm disassembly-flavor set|show arm disassembler
4360 othernames set arm disassembler
4361 set|show remotedebug set|show debug remote
4362 set|show archdebug set|show debug arch
4363 set|show eventdebug set|show debug event
4366 * New BSD user-level threads support
4368 It is now possible to debug programs using the user-level threads
4369 library on OpenBSD and FreeBSD. Currently supported (target)
4372 FreeBSD/amd64 x86_64-*-freebsd*
4373 FreeBSD/i386 i386-*-freebsd*
4374 OpenBSD/i386 i386-*-openbsd*
4376 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4377 are not yet supported.
4379 * New support for Matsushita MN10300 w/sim added
4380 (Work in progress). mn10300-elf.
4382 * REMOVED configurations and files
4384 VxWorks and the XDR protocol *-*-vxworks
4385 Motorola MCORE mcore-*-*
4386 National Semiconductor NS32000 ns32k-*-*
4388 * New "set print array-indexes" command
4390 After turning this setting "on", GDB prints the index of each element
4391 when displaying arrays. The default is "off" to preserve the previous
4394 * VAX floating point support
4396 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4398 * User-defined command support
4400 In addition to using $arg0..$arg9 for argument passing, it is now possible
4401 to use $argc to determine now many arguments have been passed. See the
4402 section on user-defined commands in the user manual for more information.
4404 *** Changes in GDB 6.3:
4406 * New command line option
4408 GDB now accepts -l followed by a number to set the timeout for remote
4411 * GDB works with GCC -feliminate-dwarf2-dups
4413 GDB now supports a more compact representation of DWARF-2 debug
4414 information using DW_FORM_ref_addr references. These are produced
4415 by GCC with the option -feliminate-dwarf2-dups and also by some
4416 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4417 to use -feliminate-dwarf2-dups.
4419 * Internationalization
4421 When supported by the host system, GDB will be built with
4422 internationalization (libintl). The task of marking up the sources is
4423 continued, we're looking forward to our first translation.
4427 Initial support for debugging programs compiled with the GNAT
4428 implementation of the Ada programming language has been integrated
4429 into GDB. In this release, support is limited to expression evaluation.
4431 * New native configurations
4433 GNU/Linux/m32r m32r-*-linux-gnu
4437 GDB's remote protocol now includes support for the 'p' packet. This
4438 packet is used to fetch individual registers from a remote inferior.
4440 * END-OF-LIFE registers[] compatibility module
4442 GDB's internal register infrastructure has been completely rewritten.
4443 The new infrastructure making possible the implementation of key new
4444 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4447 GDB 6.3 will be the last release to include the the registers[]
4448 compatibility module that allowed out-of-date configurations to
4449 continue to work. This change directly impacts the following
4459 powerpc bdm protocol
4461 Unless there is activity to revive these configurations, they will be
4462 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4464 * OBSOLETE configurations and files
4466 Configurations that have been declared obsolete in this release have
4467 been commented out. Unless there is activity to revive these
4468 configurations, the next release of GDB will have their sources
4469 permanently REMOVED.
4478 *** Changes in GDB 6.2.1:
4480 * MIPS `break main; run' gave an heuristic-fence-post warning
4482 When attempting to run even a simple program, a warning about
4483 heuristic-fence-post being hit would be reported. This problem has
4486 * MIPS IRIX 'long double' crashed GDB
4488 When examining a long double variable, GDB would get a segmentation
4489 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4490 IRIX long double values).
4494 A bug in the VAX stack code was causing problems with the "next"
4495 command. This problem has been fixed.
4497 *** Changes in GDB 6.2:
4499 * Fix for ``many threads''
4501 On GNU/Linux systems that use the NPTL threads library, a program
4502 rapidly creating and deleting threads would confuse GDB leading to the
4505 ptrace: No such process.
4506 thread_db_get_info: cannot get thread info: generic error
4508 This problem has been fixed.
4510 * "-async" and "-noasync" options removed.
4512 Support for the broken "-noasync" option has been removed (it caused
4515 * New ``start'' command.
4517 This command runs the program until the begining of the main procedure.
4519 * New BSD Kernel Data Access Library (libkvm) interface
4521 Using ``target kvm'' it is now possible to debug kernel core dumps and
4522 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4523 platforms. Currently supported (native-only) configurations are:
4525 FreeBSD/amd64 x86_64-*-freebsd*
4526 FreeBSD/i386 i?86-*-freebsd*
4527 NetBSD/i386 i?86-*-netbsd*
4528 NetBSD/m68k m68*-*-netbsd*
4529 NetBSD/sparc sparc-*-netbsd*
4530 OpenBSD/amd64 x86_64-*-openbsd*
4531 OpenBSD/i386 i?86-*-openbsd*
4532 OpenBSD/m68k m68*-openbsd*
4533 OpenBSD/sparc sparc-*-openbsd*
4535 * Signal trampoline code overhauled
4537 Many generic problems with GDB's signal handling code have been fixed.
4538 These include: backtraces through non-contiguous stacks; recognition
4539 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4540 call; backtrace through a signal trampoline; step into and out of
4541 signal handlers; and single-stepping in the signal trampoline.
4543 Please note that kernel bugs are a limiting factor here. These
4544 features have been shown to work on an s390 GNU/Linux system that
4545 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4547 * Cygwin support for DWARF 2 added.
4549 * New native configurations
4551 GNU/Linux/hppa hppa*-*-linux*
4552 OpenBSD/hppa hppa*-*-openbsd*
4553 OpenBSD/m68k m68*-*-openbsd*
4554 OpenBSD/m88k m88*-*-openbsd*
4555 OpenBSD/powerpc powerpc-*-openbsd*
4556 NetBSD/vax vax-*-netbsd*
4557 OpenBSD/vax vax-*-openbsd*
4559 * END-OF-LIFE frame compatibility module
4561 GDB's internal frame infrastructure has been completely rewritten.
4562 The new infrastructure making it possible to support key new features
4563 including DWARF 2 Call Frame Information. To aid in the task of
4564 migrating old configurations to this new infrastructure, a
4565 compatibility module, that allowed old configurations to continue to
4566 work, was also included.
4568 GDB 6.2 will be the last release to include this frame compatibility
4569 module. This change directly impacts the following configurations:
4579 Unless there is activity to revive these configurations, they will be
4580 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4582 * REMOVED configurations and files
4584 Sun 3, running SunOS 3 m68*-*-sunos3*
4585 Sun 3, running SunOS 4 m68*-*-sunos4*
4586 Sun 2, running SunOS 3 m68000-*-sunos3*
4587 Sun 2, running SunOS 4 m68000-*-sunos4*
4588 Motorola 680x0 running LynxOS m68*-*-lynxos*
4589 AT&T 3b1/Unix pc m68*-att-*
4590 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4591 decstation mips-dec-* mips-little-*
4592 riscos mips-*-riscos* mips-*-sysv*
4593 sonymips mips-sony-*
4594 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4596 *** Changes in GDB 6.1.1:
4598 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4600 The TUI (Text-mode User Interface) is now built as part of a default
4601 GDB configuration. It is enabled by either selecting the TUI with the
4602 command line option "-i=tui" or by running the separate "gdbtui"
4603 program. For more information on the TUI, see the manual "Debugging
4606 * Pending breakpoint support (also included in GDB 6.1)
4608 Support has been added to allow you to specify breakpoints in shared
4609 libraries that have not yet been loaded. If a breakpoint location
4610 cannot be found, and the "breakpoint pending" option is set to auto,
4611 GDB queries you if you wish to make the breakpoint pending on a future
4612 shared-library load. If and when GDB resolves the breakpoint symbol,
4613 the pending breakpoint is removed as one or more regular breakpoints
4616 Pending breakpoints are very useful for GCJ Java debugging.
4618 * Fixed ISO-C build problems
4620 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4621 non ISO-C code that stopped them being built using a more strict ISO-C
4622 compiler (e.g., IBM's C compiler).
4624 * Fixed build problem on IRIX 5
4626 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4627 wasn't able to compile compile on an IRIX 5 system.
4629 * Added execute permission to gdb/gdbserver/configure
4631 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4632 permission. This bug would cause configure to fail on a number of
4633 systems (Solaris, IRIX). Ref: server/519.
4635 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4637 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4638 has been updated to use constant array sizes.
4640 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4642 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4643 its generated DWARF Call Frame Info. This encoding was causing GDB to
4644 panic, that panic has been fixed. Ref: gdb/1628.
4646 * Fixed a problem when examining parameters in shared library code.
4648 When examining parameters in optimized shared library code generated
4649 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4650 not available''. GDB now correctly displays the variable's value.
4652 *** Changes in GDB 6.1:
4654 * Removed --with-mmalloc
4656 Support for the mmalloc memory manager has been removed, as it
4657 conflicted with the internal gdb byte cache.
4659 * Changes in AMD64 configurations
4661 The AMD64 target now includes the %cs and %ss registers. As a result
4662 the AMD64 remote protocol has changed; this affects the floating-point
4663 and SSE registers. If you rely on those registers for your debugging,
4664 you should upgrade gdbserver on the remote side.
4666 * Revised SPARC target
4668 The SPARC target has been completely revised, incorporating the
4669 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4670 support for LynxOS and SunOS 4 has been dropped. Calling functions
4671 from within GDB on operating systems with a non-executable stack
4672 (Solaris, OpenBSD) now works.
4676 GDB has a new C++ demangler which does a better job on the mangled
4677 names generated by current versions of g++. It also runs faster, so
4678 with this and other changes gdb should now start faster on large C++
4681 * DWARF 2 Location Expressions
4683 GDB support for location expressions has been extended to support function
4684 arguments and frame bases. Older versions of GDB could crash when they
4687 * C++ nested types and namespaces
4689 GDB's support for nested types and namespaces in C++ has been
4690 improved, especially if you use the DWARF 2 debugging format. (This
4691 is the default for recent versions of GCC on most platforms.)
4692 Specifically, if you have a class "Inner" defined within a class or
4693 namespace "Outer", then GDB realizes that the class's name is
4694 "Outer::Inner", not simply "Inner". This should greatly reduce the
4695 frequency of complaints about not finding RTTI symbols. In addition,
4696 if you are stopped at inside of a function defined within a namespace,
4697 GDB modifies its name lookup accordingly.
4699 * New native configurations
4701 NetBSD/amd64 x86_64-*-netbsd*
4702 OpenBSD/amd64 x86_64-*-openbsd*
4703 OpenBSD/alpha alpha*-*-openbsd*
4704 OpenBSD/sparc sparc-*-openbsd*
4705 OpenBSD/sparc64 sparc64-*-openbsd*
4707 * New debugging protocols
4709 M32R with SDI protocol m32r-*-elf*
4711 * "set prompt-escape-char" command deleted.
4713 The command "set prompt-escape-char" has been deleted. This command,
4714 and its very obscure effet on GDB's prompt, was never documented,
4715 tested, nor mentioned in the NEWS file.
4717 * OBSOLETE configurations and files
4719 Configurations that have been declared obsolete in this release have
4720 been commented out. Unless there is activity to revive these
4721 configurations, the next release of GDB will have their sources
4722 permanently REMOVED.
4724 Sun 3, running SunOS 3 m68*-*-sunos3*
4725 Sun 3, running SunOS 4 m68*-*-sunos4*
4726 Sun 2, running SunOS 3 m68000-*-sunos3*
4727 Sun 2, running SunOS 4 m68000-*-sunos4*
4728 Motorola 680x0 running LynxOS m68*-*-lynxos*
4729 AT&T 3b1/Unix pc m68*-att-*
4730 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4731 decstation mips-dec-* mips-little-*
4732 riscos mips-*-riscos* mips-*-sysv*
4733 sonymips mips-sony-*
4734 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4736 * REMOVED configurations and files
4738 SGI Irix-4.x mips-sgi-irix4 or iris4
4739 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4740 Z8000 simulator z8k-zilog-none or z8ksim
4741 Matsushita MN10200 w/simulator mn10200-*-*
4742 H8/500 simulator h8500-hitachi-hms or h8500hms
4743 HP/PA running BSD hppa*-*-bsd*
4744 HP/PA running OSF/1 hppa*-*-osf*
4745 HP/PA Pro target hppa*-*-pro*
4746 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4747 386BSD i[3456]86-*-bsd*
4748 Sequent family i[3456]86-sequent-sysv4*
4749 i[3456]86-sequent-sysv*
4750 i[3456]86-sequent-bsd*
4751 SPARC running LynxOS sparc-*-lynxos*
4752 SPARC running SunOS 4 sparc-*-sunos4*
4753 Tsqware Sparclet sparclet-*-*
4754 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4756 *** Changes in GDB 6.0:
4760 Support for debugging the Objective-C programming language has been
4761 integrated into GDB.
4763 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4765 DWARF 2's Call Frame Information makes available compiler generated
4766 information that more exactly describes the program's run-time stack.
4767 By using this information, GDB is able to provide more robust stack
4770 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4771 have been updated to use a new backtrace mechanism which includes
4772 DWARF 2 CFI support.
4776 GDB's remote protocol has been extended to include support for hosted
4777 file I/O (where the remote target uses GDB's file system). See GDB's
4778 remote protocol documentation for details.
4780 * All targets using the new architecture framework.
4782 All of GDB's targets have been updated to use the new internal
4783 architecture framework. The way is now open for future GDB releases
4784 to include cross-architecture native debugging support (i386 on amd64,
4787 * GNU/Linux's Thread Local Storage (TLS)
4789 GDB now includes support for for the GNU/Linux implementation of
4790 per-thread variables.
4792 * GNU/Linux's Native POSIX Thread Library (NPTL)
4794 GDB's thread code has been updated to work with either the new
4795 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4797 * Separate debug info.
4799 GDB, in conjunction with BINUTILS, now supports a mechanism for
4800 automatically loading debug information from a separate file. Instead
4801 of shipping full debug and non-debug versions of system libraries,
4802 system integrators can now instead ship just the stripped libraries
4803 and optional debug files.
4805 * DWARF 2 Location Expressions
4807 DWARF 2 Location Expressions allow the compiler to more completely
4808 describe the location of variables (even in optimized code) to the
4811 GDB now includes preliminary support for location expressions (support
4812 for DW_OP_piece is still missing).
4816 A number of long standing bugs that caused GDB to die while starting a
4817 Java application have been fixed. GDB's Java support is now
4818 considered "useable".
4820 * GNU/Linux support for fork, vfork, and exec.
4822 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4823 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4826 * GDB supports logging output to a file
4828 There are two new commands, "set logging" and "show logging", which can be
4829 used to capture GDB's output to a file.
4831 * The meaning of "detach" has changed for gdbserver
4833 The "detach" command will now resume the application, as documented. To
4834 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4837 * d10v, m68hc11 `regs' command deprecated
4839 The `info registers' command has been updated so that it displays the
4840 registers using a format identical to the old `regs' command.
4844 A new command, "maint set profile on/off", has been added. This command can
4845 be used to enable or disable profiling while running GDB, to profile a
4846 session or a set of commands. In addition there is a new configure switch,
4847 "--enable-profiling", which will cause GDB to be compiled with profiling
4848 data, for more informative profiling results.
4850 * Default MI syntax changed to "mi2".
4852 The default MI (machine interface) syntax, enabled by the command line
4853 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4854 "mi1", can be enabled by specifying the option "-i=mi1".
4856 Support for the original "mi0" syntax (included in GDB 5.0) has been
4859 Fix for gdb/192: removed extraneous space when displaying frame level.
4860 Fix for gdb/672: update changelist is now output in mi list format.
4861 Fix for gdb/702: a -var-assign that updates the value now shows up
4862 in a subsequent -var-update.
4864 * New native configurations.
4866 FreeBSD/amd64 x86_64-*-freebsd*
4868 * Multi-arched targets.
4870 HP/PA HPUX11 hppa*-*-hpux*
4871 Renesas M32R/D w/simulator m32r-*-elf*
4873 * OBSOLETE configurations and files
4875 Configurations that have been declared obsolete in this release have
4876 been commented out. Unless there is activity to revive these
4877 configurations, the next release of GDB will have their sources
4878 permanently REMOVED.
4880 Z8000 simulator z8k-zilog-none or z8ksim
4881 Matsushita MN10200 w/simulator mn10200-*-*
4882 H8/500 simulator h8500-hitachi-hms or h8500hms
4883 HP/PA running BSD hppa*-*-bsd*
4884 HP/PA running OSF/1 hppa*-*-osf*
4885 HP/PA Pro target hppa*-*-pro*
4886 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4887 Sequent family i[3456]86-sequent-sysv4*
4888 i[3456]86-sequent-sysv*
4889 i[3456]86-sequent-bsd*
4890 Tsqware Sparclet sparclet-*-*
4891 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4893 * REMOVED configurations and files
4896 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4897 IBM AIX PS/2 i[3456]86-*-aix
4898 i386 running Mach 3.0 i[3456]86-*-mach3*
4899 i386 running Mach i[3456]86-*-mach*
4900 i386 running OSF/1 i[3456]86-*osf1mk*
4901 HP/Apollo 68k Family m68*-apollo*-sysv*,
4903 m68*-hp-bsd*, m68*-hp-hpux*
4904 Argonaut Risc Chip (ARC) arc-*-*
4905 Mitsubishi D30V d30v-*-*
4906 Fujitsu FR30 fr30-*-elf*
4907 OS/9000 i[34]86-*-os9k
4908 I960 with MON960 i960-*-coff
4910 * MIPS $fp behavior changed
4912 The convenience variable $fp, for the MIPS, now consistently returns
4913 the address of the current frame's base. Previously, depending on the
4914 context, $fp could refer to either $sp or the current frame's base
4915 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4916 The GNU Source-Level Debugger''.
4918 *** Changes in GDB 5.3:
4920 * GNU/Linux shared library multi-threaded performance improved.
4922 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4923 `/proc', in preference to `ptrace' for memory reads. This may result
4924 in an improvement in the start-up time of multi-threaded, shared
4925 library applications when run under GDB. One GDB user writes: ``loads
4926 shared libs like mad''.
4928 * ``gdbserver'' now supports multi-threaded applications on some targets
4930 Support for debugging multi-threaded applications which use
4931 the GNU/Linux LinuxThreads package has been added for
4932 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4933 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4935 * GDB now supports C/C++ preprocessor macros.
4937 GDB now expands preprocessor macro invocations in C/C++ expressions,
4938 and provides various commands for showing macro definitions and how
4941 The new command `macro expand EXPRESSION' expands any macro
4942 invocations in expression, and shows the result.
4944 The new command `show macro MACRO-NAME' shows the definition of the
4945 macro named MACRO-NAME, and where it was defined.
4947 Most compilers don't include information about macros in the debugging
4948 information by default. In GCC 3.1, for example, you need to compile
4949 your program with the options `-gdwarf-2 -g3'. If the macro
4950 information is present in the executable, GDB will read it.
4952 * Multi-arched targets.
4954 DEC Alpha (partial) alpha*-*-*
4955 DEC VAX (partial) vax-*-*
4957 National Semiconductor NS32000 (partial) ns32k-*-*
4958 Motorola 68000 (partial) m68k-*-*
4959 Motorola MCORE mcore-*-*
4963 Fujitsu FRV architecture added by Red Hat frv*-*-*
4966 * New native configurations
4968 Alpha NetBSD alpha*-*-netbsd*
4969 SH NetBSD sh*-*-netbsdelf*
4970 MIPS NetBSD mips*-*-netbsd*
4971 UltraSPARC NetBSD sparc64-*-netbsd*
4973 * OBSOLETE configurations and files
4975 Configurations that have been declared obsolete in this release have
4976 been commented out. Unless there is activity to revive these
4977 configurations, the next release of GDB will have their sources
4978 permanently REMOVED.
4980 Mitsubishi D30V d30v-*-*
4981 OS/9000 i[34]86-*-os9k
4982 IBM AIX PS/2 i[3456]86-*-aix
4983 Fujitsu FR30 fr30-*-elf*
4984 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4985 Argonaut Risc Chip (ARC) arc-*-*
4986 i386 running Mach 3.0 i[3456]86-*-mach3*
4987 i386 running Mach i[3456]86-*-mach*
4988 i386 running OSF/1 i[3456]86-*osf1mk*
4989 HP/Apollo 68k Family m68*-apollo*-sysv*,
4991 m68*-hp-bsd*, m68*-hp-hpux*
4992 I960 with MON960 i960-*-coff
4994 * OBSOLETE languages
4996 CHILL, a Pascal like language used by telecommunications companies.
4998 * REMOVED configurations and files
5000 AMD 29k family via UDI a29k-amd-udi, udi29k
5001 A29K VxWorks a29k-*-vxworks
5002 AMD 29000 embedded, using EBMON a29k-none-none
5003 AMD 29000 embedded with COFF a29k-none-coff
5004 AMD 29000 embedded with a.out a29k-none-aout
5006 testsuite/gdb.hp/gdb.threads-hp/ directory
5008 * New command "set max-user-call-depth <nnn>"
5010 This command allows the user to limit the call depth of user-defined
5011 commands. The default is 1024.
5013 * Changes in FreeBSD/i386 native debugging.
5015 Support for the "generate-core-file" has been added.
5017 * New commands "dump", "append", and "restore".
5019 These commands allow data to be copied from target memory
5020 to a bfd-format or binary file (dump and append), and back
5021 from a file into memory (restore).
5023 * Improved "next/step" support on multi-processor Alpha Tru64.
5025 The previous single-step mechanism could cause unpredictable problems,
5026 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5027 of a software single-step mechanism prevents this.
5029 *** Changes in GDB 5.2.1:
5037 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5038 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5039 Fix, by Joel Brobecker imported from mainline.
5041 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5042 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5043 Fix, by Fred Fish, imported from mainline.
5045 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5046 Surprisingly enough, it works now.
5047 By Michal Ludvig, imported from mainline.
5049 i386 hardware watchpoint support:
5050 avoid misses on second run for some targets.
5051 By Pierre Muller, imported from mainline.
5053 *** Changes in GDB 5.2:
5055 * New command "set trust-readonly-sections on[off]".
5057 This command is a hint that tells gdb that read-only sections
5058 really are read-only (ie. that their contents will not change).
5059 In this mode, gdb will go to the object file rather than the
5060 target to read memory from read-only sections (such as ".text").
5061 This can be a significant performance improvement on some
5062 (notably embedded) targets.
5064 * New command "generate-core-file" (or "gcore").
5066 This new gdb command allows the user to drop a core file of the child
5067 process state at any time. So far it's been implemented only for
5068 GNU/Linux and Solaris, but should be relatively easily ported to other
5069 hosts. Argument is core file name (defaults to core.<pid>).
5071 * New command line option
5073 GDB now accepts --pid or -p followed by a process id.
5075 * Change in command line behavior -- corefiles vs. process ids.
5077 There is a subtle behavior in the way in which GDB handles
5078 command line arguments. The first non-flag argument is always
5079 a program to debug, but the second non-flag argument may either
5080 be a corefile or a process id. Previously, GDB would attempt to
5081 open the second argument as a corefile, and if that failed, would
5082 issue a superfluous error message and then attempt to attach it as
5083 a process. Now, if the second argument begins with a non-digit,
5084 it will be treated as a corefile. If it begins with a digit,
5085 GDB will attempt to attach it as a process, and if no such process
5086 is found, will then attempt to open it as a corefile.
5088 * Changes in ARM configurations.
5090 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5091 configuration is fully multi-arch.
5093 * New native configurations
5095 ARM NetBSD arm*-*-netbsd*
5096 x86 OpenBSD i[3456]86-*-openbsd*
5097 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5098 Sparc64 running FreeBSD sparc64-*-freebsd*
5102 Sanyo XStormy16 xstormy16-elf
5104 * OBSOLETE configurations and files
5106 Configurations that have been declared obsolete in this release have
5107 been commented out. Unless there is activity to revive these
5108 configurations, the next release of GDB will have their sources
5109 permanently REMOVED.
5111 AMD 29k family via UDI a29k-amd-udi, udi29k
5112 A29K VxWorks a29k-*-vxworks
5113 AMD 29000 embedded, using EBMON a29k-none-none
5114 AMD 29000 embedded with COFF a29k-none-coff
5115 AMD 29000 embedded with a.out a29k-none-aout
5117 testsuite/gdb.hp/gdb.threads-hp/ directory
5119 * REMOVED configurations and files
5121 TI TMS320C80 tic80-*-*
5123 PowerPC Solaris powerpcle-*-solaris*
5124 PowerPC Windows NT powerpcle-*-cygwin32
5125 PowerPC Netware powerpc-*-netware*
5126 Harris/CXUX m88k m88*-harris-cxux*
5127 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5128 ns32k-utek-sysv* ns32k-utek-*
5129 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5130 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5131 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5132 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5133 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5135 * Changes to command line processing
5137 The new `--args' feature can be used to specify command-line arguments
5138 for the inferior from gdb's command line.
5140 * Changes to key bindings
5142 There is a new `operate-and-get-next' function bound to `C-o'.
5144 *** Changes in GDB 5.1.1
5146 Fix compile problem on DJGPP.
5148 Fix a problem with floating-point registers on the i386 being
5151 Fix to stop GDB crashing on .debug_str debug info.
5153 Numerous documentation fixes.
5155 Numerous testsuite fixes.
5157 *** Changes in GDB 5.1:
5159 * New native configurations
5161 Alpha FreeBSD alpha*-*-freebsd*
5162 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5163 MIPS GNU/Linux mips*-*-linux*
5164 MIPS SGI Irix 6.x mips*-sgi-irix6*
5165 ia64 AIX ia64-*-aix*
5166 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5170 Motorola 68HC11 and 68HC12 m68hc11-elf
5172 UltraSparc running GNU/Linux sparc64-*-linux*
5174 * OBSOLETE configurations and files
5176 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5177 Harris/CXUX m88k m88*-harris-cxux*
5178 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5179 ns32k-utek-sysv* ns32k-utek-*
5180 TI TMS320C80 tic80-*-*
5182 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5183 PowerPC Solaris powerpcle-*-solaris*
5184 PowerPC Windows NT powerpcle-*-cygwin32
5185 PowerPC Netware powerpc-*-netware*
5186 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5187 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5188 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5189 Apple Macintosh (MPW) host N/A
5191 stuff.c (Program to stuff files into a specially prepared space in kdb)
5192 kdb-start.c (Main loop for the standalone kernel debugger)
5194 Configurations that have been declared obsolete in this release have
5195 been commented out. Unless there is activity to revive these
5196 configurations, the next release of GDB will have their sources
5197 permanently REMOVED.
5199 * REMOVED configurations and files
5201 Altos 3068 m68*-altos-*
5202 Convex c1-*-*, c2-*-*
5204 ARM RISCix arm-*-* (as host)
5208 * GDB has been converted to ISO C.
5210 GDB's source code has been converted to ISO C. In particular, the
5211 sources are fully protoized, and rely on standard headers being
5216 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5218 * The MI enabled by default.
5220 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5221 revised and enabled by default. Packages which use GDB as a debugging
5222 engine behind a UI or another front end are encouraged to switch to
5223 using the GDB/MI interface, instead of the old annotations interface
5224 which is now deprecated.
5226 * Support for debugging Pascal programs.
5228 GDB now includes support for debugging Pascal programs. The following
5229 main features are supported:
5231 - Pascal-specific data types such as sets;
5233 - automatic recognition of Pascal sources based on file-name
5236 - Pascal-style display of data types, variables, and functions;
5238 - a Pascal expression parser.
5240 However, some important features are not yet supported.
5242 - Pascal string operations are not supported at all;
5244 - there are some problems with boolean types;
5246 - Pascal type hexadecimal constants are not supported
5247 because they conflict with the internal variables format;
5249 - support for Pascal objects and classes is not full yet;
5251 - unlike Pascal, GDB is case-sensitive for symbol names.
5253 * Changes in completion.
5255 Commands such as `shell', `run' and `set args', which pass arguments
5256 to inferior programs, now complete on file names, similar to what
5257 users expect at the shell prompt.
5259 Commands which accept locations, such as `disassemble', `print',
5260 `breakpoint', `until', etc. now complete on filenames as well as
5261 program symbols. Thus, if you type "break foob TAB", and the source
5262 files linked into the programs include `foobar.c', that file name will
5263 be one of the candidates for completion. However, file names are not
5264 considered for completion after you typed a colon that delimits a file
5265 name from a name of a function in that file, as in "break foo.c:bar".
5267 `set demangle-style' completes on available demangling styles.
5269 * New platform-independent commands:
5271 It is now possible to define a post-hook for a command as well as a
5272 hook that runs before the command. For more details, see the
5273 documentation of `hookpost' in the GDB manual.
5275 * Changes in GNU/Linux native debugging.
5277 Support for debugging multi-threaded programs has been completely
5278 revised for all platforms except m68k and sparc. You can now debug as
5279 many threads as your system allows you to have.
5281 Attach/detach is supported for multi-threaded programs.
5283 Support for SSE registers was added for x86. This doesn't work for
5284 multi-threaded programs though.
5286 * Changes in MIPS configurations.
5288 Multi-arch support is enabled for all MIPS configurations.
5290 GDB can now be built as native debugger on SGI Irix 6.x systems for
5291 debugging n32 executables. (Debugging 64-bit executables is not yet
5294 * Unified support for hardware watchpoints in all x86 configurations.
5296 Most (if not all) native x86 configurations support hardware-assisted
5297 breakpoints and watchpoints in a unified manner. This support
5298 implements debug register sharing between watchpoints, which allows to
5299 put a virtually infinite number of watchpoints on the same address,
5300 and also supports watching regions up to 16 bytes with several debug
5303 The new maintenance command `maintenance show-debug-regs' toggles
5304 debugging print-outs in functions that insert, remove, and test
5305 watchpoints and hardware breakpoints.
5307 * Changes in the DJGPP native configuration.
5309 New command ``info dos sysinfo'' displays assorted information about
5310 the CPU, OS, memory, and DPMI server.
5312 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5313 display information about segment descriptors stored in GDT, LDT, and
5316 New commands ``info dos pde'' and ``info dos pte'' display entries
5317 from Page Directory and Page Tables (for now works with CWSDPMI only).
5318 New command ``info dos address-pte'' displays the Page Table entry for
5319 a given linear address.
5321 GDB can now pass command lines longer than 126 characters to the
5322 program being debugged (requires an update to the libdbg.a library
5323 which is part of the DJGPP development kit).
5325 DWARF2 debug info is now supported.
5327 It is now possible to `step' and `next' through calls to `longjmp'.
5329 * Changes in documentation.
5331 All GDB documentation was converted to GFDL, the GNU Free
5332 Documentation License.
5334 Tracepoints-related commands are now fully documented in the GDB
5337 TUI, the Text-mode User Interface, is now documented in the manual.
5339 Tracepoints-related commands are now fully documented in the GDB
5342 The "GDB Internals" manual now has an index. It also includes
5343 documentation of `ui_out' functions, GDB coding standards, x86
5344 hardware watchpoints, and memory region attributes.
5346 * GDB's version number moved to ``version.in''
5348 The Makefile variable VERSION has been replaced by the file
5349 ``version.in''. People creating GDB distributions should update the
5350 contents of this file.
5354 GUD support is now a standard part of the EMACS distribution.
5356 *** Changes in GDB 5.0:
5358 * Improved support for debugging FP programs on x86 targets
5360 Unified and much-improved support for debugging floating-point
5361 programs on all x86 targets. In particular, ``info float'' now
5362 displays the FP registers in the same format on all x86 targets, with
5363 greater level of detail.
5365 * Improvements and bugfixes in hardware-assisted watchpoints
5367 It is now possible to watch array elements, struct members, and
5368 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5369 on x86 targets no longer erroneously trigger when the address is
5372 * Improvements in the native DJGPP version of GDB
5374 The distribution now includes all the scripts and auxiliary files
5375 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5376 machines ``out of the box''.
5378 The DJGPP version can now debug programs that use signals. It is
5379 possible to catch signals that happened in the debuggee, deliver
5380 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5381 would kill the program being debugged.) Programs that hook hardware
5382 interrupts (keyboard, timer, etc.) can also be debugged.
5384 It is now possible to debug DJGPP programs that redirect their
5385 standard handles or switch them to raw (as opposed to cooked) mode, or
5386 even close them. The command ``run < foo > bar'' works as expected,
5387 and ``info terminal'' reports useful information about the debuggee's
5388 terminal, including raw/cooked mode, redirection, etc.
5390 The DJGPP version now uses termios functions for console I/O, which
5391 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5394 DOS-style file names with drive letters are now fully supported by
5397 It is now possible to debug DJGPP programs that switch their working
5398 directory. It is also possible to rerun the debuggee any number of
5399 times without restarting GDB; thus, you can use the same setup,
5400 breakpoints, etc. for many debugging sessions.
5402 * New native configurations
5404 ARM GNU/Linux arm*-*-linux*
5405 PowerPC GNU/Linux powerpc-*-linux*
5409 Motorola MCore mcore-*-*
5410 x86 VxWorks i[3456]86-*-vxworks*
5411 PowerPC VxWorks powerpc-*-vxworks*
5412 TI TMS320C80 tic80-*-*
5414 * OBSOLETE configurations
5416 Altos 3068 m68*-altos-*
5417 Convex c1-*-*, c2-*-*
5419 ARM RISCix arm-*-* (as host)
5422 Configurations that have been declared obsolete will be commented out,
5423 but the code will be left in place. If there is no activity to revive
5424 these configurations before the next release of GDB, the sources will
5425 be permanently REMOVED.
5427 * Gould support removed
5429 Support for the Gould PowerNode and NP1 has been removed.
5431 * New features for SVR4
5433 On SVR4 native platforms (such as Solaris), if you attach to a process
5434 without first loading a symbol file, GDB will now attempt to locate and
5435 load symbols from the running process's executable file.
5437 * Many C++ enhancements
5439 C++ support has been greatly improved. Overload resolution now works properly
5440 in almost all cases. RTTI support is on the way.
5442 * Remote targets can connect to a sub-program
5444 A popen(3) style serial-device has been added. This device starts a
5445 sub-process (such as a stand-alone simulator) and then communicates
5446 with that. The sub-program to run is specified using the syntax
5447 ``|<program> <args>'' vis:
5449 (gdb) set remotedebug 1
5450 (gdb) target extended-remote |mn10300-elf-sim program-args
5452 * MIPS 64 remote protocol
5454 A long standing bug in the mips64 remote protocol where by GDB
5455 expected certain 32 bit registers (ex SR) to be transfered as 32
5456 instead of 64 bits has been fixed.
5458 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5459 added to provide backward compatibility with older versions of GDB.
5461 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5463 The command ``set remotebinarydownload'' command has been replaced by
5464 ``set remote X-packet''. Other commands in ``set remote'' family
5465 include ``set remote P-packet''.
5467 * Breakpoint commands accept ranges.
5469 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5470 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5471 ``tracepoint passcount'' also accepts a range of tracepoints.
5473 * ``apropos'' command added.
5475 The ``apropos'' command searches through command names and
5476 documentation strings, printing out matches, making it much easier to
5477 try to find a command that does what you are looking for.
5481 A new machine oriented interface (MI) has been added to GDB. This
5482 interface is designed for debug environments running GDB as a separate
5483 process. This is part of the long term libGDB project. See the
5484 "GDB/MI" chapter of the GDB manual for further information. It can be
5485 enabled by configuring with:
5487 .../configure --enable-gdbmi
5489 *** Changes in GDB-4.18:
5491 * New native configurations
5493 HP-UX 10.20 hppa*-*-hpux10.20
5494 HP-UX 11.x hppa*-*-hpux11.0*
5495 M68K GNU/Linux m68*-*-linux*
5499 Fujitsu FR30 fr30-*-elf*
5500 Intel StrongARM strongarm-*-*
5501 Mitsubishi D30V d30v-*-*
5503 * OBSOLETE configurations
5505 Gould PowerNode, NP1 np1-*-*, pn-*-*
5507 Configurations that have been declared obsolete will be commented out,
5508 but the code will be left in place. If there is no activity to revive
5509 these configurations before the next release of GDB, the sources will
5510 be permanently REMOVED.
5514 As a compatibility experiment, GDB's source files buildsym.h and
5515 buildsym.c have been converted to pure standard C, no longer
5516 containing any K&R compatibility code. We believe that all systems in
5517 use today either come with a standard C compiler, or have a GCC port
5518 available. If this is not true, please report the affected
5519 configuration to bug-gdb@gnu.org immediately. See the README file for
5520 information about getting a standard C compiler if you don't have one
5525 GDB now uses readline 2.2.
5527 * set extension-language
5529 You can now control the mapping between filename extensions and source
5530 languages by using the `set extension-language' command. For instance,
5531 you can ask GDB to treat .c files as C++ by saying
5532 set extension-language .c c++
5533 The command `info extensions' lists all of the recognized extensions
5534 and their associated languages.
5536 * Setting processor type for PowerPC and RS/6000
5538 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5539 you can use the `set processor' command to specify what variant of the
5540 PowerPC family you are debugging. The command
5544 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5545 following PowerPC and RS6000 variants:
5547 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5548 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5550 403GC IBM PowerPC 403GC
5551 505 Motorola PowerPC 505
5552 860 Motorola PowerPC 860 or 850
5553 601 Motorola PowerPC 601
5554 602 Motorola PowerPC 602
5555 603 Motorola/IBM PowerPC 603 or 603e
5556 604 Motorola PowerPC 604 or 604e
5557 750 Motorola/IBM PowerPC 750 or 750
5559 At the moment, this command just tells GDB what to name the
5560 special-purpose processor registers. Since almost all the affected
5561 registers are inaccessible to user-level programs, this command is
5562 only useful for remote debugging in its present form.
5566 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5567 more extensive support for HP-UX. Added features include shared
5568 library support, kernel threads and hardware watchpoints for 11.00,
5569 support for HP's ANSI C and C++ compilers, and a compatibility mode
5570 for xdb and dbx commands.
5574 HP's donation includes the new concept of catchpoints, which is a
5575 generalization of the old catch command. On HP-UX, it is now possible
5576 to catch exec, fork, and vfork, as well as library loading.
5578 This means that the existing catch command has changed; its first
5579 argument now specifies the type of catch to be set up. See the
5580 output of "help catch" for a list of catchpoint types.
5582 * Debugging across forks
5584 On HP-UX, you can choose which process to debug when a fork() happens
5589 HP has donated a curses-based terminal user interface (TUI). To get
5590 it, build with --enable-tui. Although this can be enabled for any
5591 configuration, at present it only works for native HP debugging.
5593 * GDB remote protocol additions
5595 A new protocol packet 'X' that writes binary data is now available.
5596 Default behavior is to try 'X', then drop back to 'M' if the stub
5597 fails to respond. The settable variable `remotebinarydownload'
5598 allows explicit control over the use of 'X'.
5600 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5601 full 64-bit address. The command
5603 set remoteaddresssize 32
5605 can be used to revert to the old behaviour. For existing remote stubs
5606 the change should not be noticed, as the additional address information
5609 In order to assist in debugging stubs, you may use the maintenance
5610 command `packet' to send any text string to the stub. For instance,
5612 maint packet heythere
5614 sends the packet "$heythere#<checksum>". Note that it is very easy to
5615 disrupt a debugging session by sending the wrong packet at the wrong
5618 The compare-sections command allows you to compare section data on the
5619 target to what is in the executable file without uploading or
5620 downloading, by comparing CRC checksums.
5622 * Tracing can collect general expressions
5624 You may now collect general expressions at tracepoints. This requires
5625 further additions to the target-side stub; see tracepoint.c and
5626 doc/agentexpr.texi for further details.
5628 * mask-address variable for Mips
5630 For Mips targets, you may control the zeroing of the upper 32 bits of
5631 a 64-bit address by entering `set mask-address on'. This is mainly
5632 of interest to users of embedded R4xxx and R5xxx processors.
5634 * Higher serial baud rates
5636 GDB's serial code now allows you to specify baud rates 57600, 115200,
5637 230400, and 460800 baud. (Note that your host system may not be able
5638 to achieve all of these rates.)
5642 The i960 configuration now includes an initial implementation of a
5643 builtin simulator, contributed by Jim Wilson.
5646 *** Changes in GDB-4.17:
5648 * New native configurations
5650 Alpha GNU/Linux alpha*-*-linux*
5651 Unixware 2.x i[3456]86-unixware2*
5652 Irix 6.x mips*-sgi-irix6*
5653 PowerPC GNU/Linux powerpc-*-linux*
5654 PowerPC Solaris powerpcle-*-solaris*
5655 Sparc GNU/Linux sparc-*-linux*
5656 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5660 Argonaut Risc Chip (ARC) arc-*-*
5661 Hitachi H8/300S h8300*-*-*
5662 Matsushita MN10200 w/simulator mn10200-*-*
5663 Matsushita MN10300 w/simulator mn10300-*-*
5664 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5665 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5666 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5667 Mitsubishi D10V w/simulator d10v-*-*
5668 Mitsubishi M32R/D w/simulator m32r-*-elf*
5669 Tsqware Sparclet sparclet-*-*
5670 NEC V850 w/simulator v850-*-*
5672 * New debugging protocols
5674 ARM with RDI protocol arm*-*-*
5675 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5676 DDB and LSI variants of PMON protocol mips*-*-*
5677 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5678 PowerPC with SDS protocol powerpc{,le}-*-eabi
5679 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5683 All configurations can now understand and use the DWARF 2 debugging
5684 format. The choice is automatic, if the symbol file contains DWARF 2
5689 GDB now includes basic Java language support. This support is
5690 only useful with Java compilers that produce native machine code.
5692 * solib-absolute-prefix and solib-search-path
5694 For SunOS and SVR4 shared libraries, you may now set the prefix for
5695 loading absolute shared library symbol files, and the search path for
5696 locating non-absolute shared library symbol files.
5698 * Live range splitting
5700 GDB can now effectively debug code for which GCC has performed live
5701 range splitting as part of its optimization. See gdb/doc/LRS for
5702 more details on the expected format of the stabs information.
5706 GDB's support for the GNU Hurd, including thread debugging, has been
5707 updated to work with current versions of the Hurd.
5711 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5712 instruction set. ARM GDB automatically detects when Thumb
5713 instructions are in use, and adjusts disassembly and backtracing
5718 GDB's MIPS target configurations now handle the MIP16 16-bit
5723 GDB now includes support for overlays; if an executable has been
5724 linked such that multiple sections are based at the same address, GDB
5725 will decide which section to use for symbolic info. You can choose to
5726 control the decision manually, using overlay commands, or implement
5727 additional target-side support and use "overlay load-target" to bring
5728 in the overlay mapping. Do "help overlay" for more detail.
5732 The command "info symbol <address>" displays information about
5733 the symbol at the specified address.
5737 The standard remote protocol now includes an extension that allows
5738 asynchronous collection and display of trace data. This requires
5739 extensive support in the target-side debugging stub. Tracing mode
5740 includes a new interaction mode in GDB and new commands: see the
5741 file tracepoint.c for more details.
5745 Configurations for embedded MIPS now include a simulator contributed
5746 by Cygnus Solutions. The simulator supports the instruction sets
5747 of most MIPS variants.
5751 Sparc configurations may now include the ERC32 simulator contributed
5752 by the European Space Agency. The simulator is not built into
5753 Sparc targets by default; configure with --enable-sim to include it.
5757 For target configurations that may include multiple variants of a
5758 basic architecture (such as MIPS and SH), you may now set the
5759 architecture explicitly. "set arch" sets, "info arch" lists
5760 the possible architectures.
5762 *** Changes in GDB-4.16:
5764 * New native configurations
5766 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5767 M68K NetBSD m68k-*-netbsd*
5768 PowerPC AIX 4.x powerpc-*-aix*
5769 PowerPC MacOS powerpc-*-macos*
5770 PowerPC Windows NT powerpcle-*-cygwin32
5771 RS/6000 AIX 4.x rs6000-*-aix4*
5775 ARM with RDP protocol arm-*-*
5776 I960 with MON960 i960-*-coff
5777 MIPS VxWorks mips*-*-vxworks*
5778 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5779 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5781 Matra Sparclet sparclet-*-*
5785 The powerpc-eabi configuration now includes the PSIM simulator,
5786 contributed by Andrew Cagney, with assistance from Mike Meissner.
5787 PSIM is a very elaborate model of the PowerPC, including not only
5788 basic instruction set execution, but also details of execution unit
5789 performance and I/O hardware. See sim/ppc/README for more details.
5793 GDB now works with Solaris 2.5.
5795 * Windows 95/NT native
5797 GDB will now work as a native debugger on Windows 95 and Windows NT.
5798 To build it from source, you must use the "gnu-win32" environment,
5799 which uses a DLL to emulate enough of Unix to run the GNU tools.
5800 Further information, binaries, and sources are available at
5801 ftp.cygnus.com, under pub/gnu-win32.
5803 * dont-repeat command
5805 If a user-defined command includes the command `dont-repeat', then the
5806 command will not be repeated if the user just types return. This is
5807 useful if the command is time-consuming to run, so that accidental
5808 extra keystrokes don't run the same command many times.
5810 * Send break instead of ^C
5812 The standard remote protocol now includes an option to send a break
5813 rather than a ^C to the target in order to interrupt it. By default,
5814 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5816 * Remote protocol timeout
5818 The standard remote protocol includes a new variable `remotetimeout'
5819 that allows you to set the number of seconds before GDB gives up trying
5820 to read from the target. The default value is 2.
5822 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5824 By default GDB will automatically keep track of objects as they are
5825 loaded and unloaded by the dynamic linker. By using the command `set
5826 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5827 when shared library events occur, thus allowing you to set breakpoints
5828 in shared libraries which are explicitly loaded by the inferior.
5830 Note this feature does not work on hpux8. On hpux9 you must link
5831 /usr/lib/end.o into your program. This feature should work
5832 automatically on hpux10.
5834 * Irix 5.x hardware watchpoint support
5836 Irix 5 configurations now support the use of hardware watchpoints.
5838 * Mips protocol "SYN garbage limit"
5840 When debugging a Mips target using the `target mips' protocol, you
5841 may set the number of characters that GDB will ignore by setting
5842 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5843 every character. The default value is 1050.
5845 * Recording and replaying remote debug sessions
5847 If you set `remotelogfile' to the name of a file, gdb will write to it
5848 a recording of a remote debug session. This recording may then be
5849 replayed back to gdb using "gdbreplay". See gdbserver/README for
5850 details. This is useful when you have a problem with GDB while doing
5851 remote debugging; you can make a recording of the session and send it
5852 to someone else, who can then recreate the problem.
5854 * Speedups for remote debugging
5856 GDB includes speedups for downloading and stepping MIPS systems using
5857 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5858 and more efficient S-record downloading.
5860 * Memory use reductions and statistics collection
5862 GDB now uses less memory and reports statistics about memory usage.
5863 Try the `maint print statistics' command, for example.
5865 *** Changes in GDB-4.15:
5867 * Psymtabs for XCOFF
5869 The symbol reader for AIX GDB now uses partial symbol tables. This
5870 can greatly improve startup time, especially for large executables.
5872 * Remote targets use caching
5874 Remote targets now use a data cache to speed up communication with the
5875 remote side. The data cache could lead to incorrect results because
5876 it doesn't know about volatile variables, thus making it impossible to
5877 debug targets which use memory mapped I/O devices. `set remotecache
5878 off' turns the the data cache off.
5880 * Remote targets may have threads
5882 The standard remote protocol now includes support for multiple threads
5883 in the target system, using new protocol commands 'H' and 'T'. See
5884 gdb/remote.c for details.
5888 If GDB is configured with `--enable-netrom', then it will include
5889 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5890 acts as though it is a bank of ROM on the target board, but you can
5891 write into it over the network. GDB's support consists only of
5892 support for fast loading into the emulated ROM; to debug, you must use
5893 another protocol, such as standard remote protocol. The usual
5894 sequence is something like
5896 target nrom <netrom-hostname>
5898 target remote <netrom-hostname>:1235
5902 GDB now includes support for the Apple Macintosh, as a host only. It
5903 may be run as either an MPW tool or as a standalone application, and
5904 it can debug through the serial port. All the usual GDB commands are
5905 available, but to the target command, you must supply "serial" as the
5906 device type instead of "/dev/ttyXX". See mpw-README in the main
5907 directory for more information on how to build. The MPW configuration
5908 scripts */mpw-config.in support only a few targets, and only the
5909 mips-idt-ecoff target has been tested.
5913 GDB configuration now uses autoconf. This is not user-visible,
5914 but does simplify configuration and building.
5918 GDB now supports hpux10.
5920 *** Changes in GDB-4.14:
5922 * New native configurations
5924 x86 FreeBSD i[345]86-*-freebsd
5925 x86 NetBSD i[345]86-*-netbsd
5926 NS32k NetBSD ns32k-*-netbsd
5927 Sparc NetBSD sparc-*-netbsd
5931 A29K VxWorks a29k-*-vxworks
5932 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5933 CPU32 EST-300 emulator m68*-*-est*
5934 PowerPC ELF powerpc-*-elf
5937 * Alpha OSF/1 support for procfs
5939 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5940 possible to attach to running processes. As the mounting of the /proc
5941 filesystem is optional on the Alpha, GDB automatically determines
5942 the availability of /proc during startup. This can lead to problems
5943 if /proc is unmounted after GDB has been started.
5945 * Arguments to user-defined commands
5947 User commands may accept up to 10 arguments separated by whitespace.
5948 Arguments are accessed within the user command via $arg0..$arg9. A
5951 print $arg0 + $arg1 + $arg2
5953 To execute the command use:
5956 Defines the command "adder" which prints the sum of its three arguments.
5957 Note the arguments are text substitutions, so they may reference variables,
5958 use complex expressions, or even perform inferior function calls.
5960 * New `if' and `while' commands
5962 This makes it possible to write more sophisticated user-defined
5963 commands. Both commands take a single argument, which is the
5964 expression to evaluate, and must be followed by the commands to
5965 execute, one per line, if the expression is nonzero, the list being
5966 terminated by the word `end'. The `if' command list may include an
5967 `else' word, which causes the following commands to be executed only
5968 if the expression is zero.
5970 * Fortran source language mode
5972 GDB now includes partial support for Fortran 77. It will recognize
5973 Fortran programs and can evaluate a subset of Fortran expressions, but
5974 variables and functions may not be handled correctly. GDB will work
5975 with G77, but does not yet know much about symbols emitted by other
5978 * Better HPUX support
5980 Most debugging facilities now work on dynamic executables for HPPAs
5981 running hpux9 or later. You can attach to running dynamically linked
5982 processes, but by default the dynamic libraries will be read-only, so
5983 for instance you won't be able to put breakpoints in them. To change
5984 that behavior do the following before running the program:
5990 This will cause the libraries to be mapped private and read-write.
5991 To revert to the normal behavior, do this:
5997 You cannot set breakpoints or examine data in the library until after
5998 the library is loaded if the function/data symbols do not have
6001 GDB can now also read debug symbols produced by the HP C compiler on
6002 HPPAs (sorry, no C++, Fortran or 68k support).
6004 * Target byte order now dynamically selectable
6006 You can choose which byte order to use with a target system, via the
6007 commands "set endian big" and "set endian little", and you can see the
6008 current setting by using "show endian". You can also give the command
6009 "set endian auto", in which case GDB will use the byte order
6010 associated with the executable. Currently, only embedded MIPS
6011 configurations support dynamic selection of target byte order.
6013 * New DOS host serial code
6015 This version uses DPMI interrupts to handle buffered I/O, so you
6016 no longer need to run asynctsr when debugging boards connected to
6019 *** Changes in GDB-4.13:
6021 * New "complete" command
6023 This lists all the possible completions for the rest of the line, if it
6024 were to be given as a command itself. This is intended for use by emacs.
6026 * Trailing space optional in prompt
6028 "set prompt" no longer adds a space for you after the prompt you set. This
6029 allows you to set a prompt which ends in a space or one that does not.
6031 * Breakpoint hit counts
6033 "info break" now displays a count of the number of times the breakpoint
6034 has been hit. This is especially useful in conjunction with "ignore"; you
6035 can ignore a large number of breakpoint hits, look at the breakpoint info
6036 to see how many times the breakpoint was hit, then run again, ignoring one
6037 less than that number, and this will get you quickly to the last hit of
6040 * Ability to stop printing at NULL character
6042 "set print null-stop" will cause GDB to stop printing the characters of
6043 an array when the first NULL is encountered. This is useful when large
6044 arrays actually contain only short strings.
6046 * Shared library breakpoints
6048 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6049 breakpoints in shared libraries before the executable is run.
6051 * Hardware watchpoints
6053 There is a new hardware breakpoint for the watch command for sparclite
6054 targets. See gdb/sparclite/hw_breakpoint.note.
6056 Hardware watchpoints are also now supported under GNU/Linux.
6060 Annotations have been added. These are for use with graphical interfaces,
6061 and are still experimental. Currently only gdba.el uses these.
6063 * Improved Irix 5 support
6065 GDB now works properly with Irix 5.2.
6067 * Improved HPPA support
6069 GDB now works properly with the latest GCC and GAS.
6071 * New native configurations
6073 Sequent PTX4 i[34]86-sequent-ptx4
6074 HPPA running OSF/1 hppa*-*-osf*
6075 Atari TT running SVR4 m68*-*-sysv4*
6076 RS/6000 LynxOS rs6000-*-lynxos*
6080 OS/9000 i[34]86-*-os9k
6081 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6084 * Hitachi SH7000 and E7000-PC ICE support
6086 There is now support for communicating with the Hitachi E7000-PC ICE.
6087 This is available automatically when GDB is configured for the SH.
6091 As usual, a variety of small fixes and improvements, both generic
6092 and configuration-specific. See the ChangeLog for more detail.
6094 *** Changes in GDB-4.12:
6096 * Irix 5 is now supported
6100 GDB-4.12 on the HPPA has a number of changes which make it unable
6101 to debug the output from the currently released versions of GCC and
6102 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6103 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6104 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6107 *** Changes in GDB-4.11:
6109 * User visible changes:
6113 The "set remotedebug" option is now consistent between the mips remote
6114 target, remote targets using the gdb-specific protocol, UDI (AMD's
6115 debug protocol for the 29k) and the 88k bug monitor. It is now an
6116 integer specifying a debug level (normally 0 or 1, but 2 means more
6117 debugging info for the mips target).
6119 * DEC Alpha native support
6121 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6122 debug info, but GDB works fairly well with the DEC compiler and should
6123 work with a future GCC release. See the README file for a few
6124 Alpha-specific notes.
6126 * Preliminary thread implementation
6128 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6130 * LynxOS native and target support for 386
6132 This release has been hosted on LynxOS 2.2, and also can be configured
6133 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6136 * Improvements in C++ mangling/demangling.
6138 This release has much better g++ debugging, specifically in name
6139 mangling/demangling, virtual function calls, print virtual table,
6140 call methods, ...etc.
6142 *** Changes in GDB-4.10:
6144 * User visible changes:
6146 Remote debugging using the GDB-specific (`target remote') protocol now
6147 supports the `load' command. This is only useful if you have some
6148 other way of getting the stub to the target system, and you can put it
6149 somewhere in memory where it won't get clobbered by the download.
6151 Filename completion now works.
6153 When run under emacs mode, the "info line" command now causes the
6154 arrow to point to the line specified. Also, "info line" prints
6155 addresses in symbolic form (as well as hex).
6157 All vxworks based targets now support a user settable option, called
6158 vxworks-timeout. This option represents the number of seconds gdb
6159 should wait for responses to rpc's. You might want to use this if
6160 your vxworks target is, perhaps, a slow software simulator or happens
6161 to be on the far side of a thin network line.
6165 This release contains support for using a DEC alpha as a GDB host for
6166 cross debugging. Native alpha debugging is not supported yet.
6169 *** Changes in GDB-4.9:
6173 This is the first GDB release which is accompanied by a matching testsuite.
6174 The testsuite requires installation of dejagnu, which should be available
6175 via ftp from most sites that carry GNU software.
6179 'Cfront' style demangling has had its name changed to 'ARM' style, to
6180 emphasize that it was written from the specifications in the C++ Annotated
6181 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6182 disclaimers, it still generated too much confusion with users attempting to
6183 use gdb with AT&T cfront.
6187 GDB now uses a standard remote interface to a simulator library.
6188 So far, the library contains simulators for the Zilog Z8001/2, the
6189 Hitachi H8/300, H8/500 and Super-H.
6191 * New targets supported
6193 H8/300 simulator h8300-hitachi-hms or h8300hms
6194 H8/500 simulator h8500-hitachi-hms or h8500hms
6195 SH simulator sh-hitachi-hms or sh
6196 Z8000 simulator z8k-zilog-none or z8ksim
6197 IDT MIPS board over serial line mips-idt-ecoff
6199 Cross-debugging to GO32 targets is supported. It requires a custom
6200 version of the i386-stub.c module which is integrated with the
6201 GO32 memory extender.
6203 * New remote protocols
6205 MIPS remote debugging protocol.
6207 * New source languages supported
6209 This version includes preliminary support for Chill, a Pascal like language
6210 used by telecommunications companies. Chill support is also being integrated
6211 into the GNU compiler, but we don't know when it will be publically available.
6214 *** Changes in GDB-4.8:
6216 * HP Precision Architecture supported
6218 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6219 version of this support was available as a set of patches from the
6220 University of Utah. GDB does not support debugging of programs
6221 compiled with the HP compiler, because HP will not document their file
6222 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6223 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6225 Many problems in the preliminary version have been fixed.
6227 * Faster and better demangling
6229 We have improved template demangling and fixed numerous bugs in the GNU style
6230 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6231 character types (wchar_t) are now supported. Demangling of each symbol is now
6232 only done once, and is cached when the symbol table for a file is read in.
6233 This results in a small increase in memory usage for C programs, a moderate
6234 increase in memory usage for C++ programs, and a fantastic speedup in
6237 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6238 from the specifications in the Annotated Reference Manual, which AT&T's
6239 compiler does not actually implement.
6241 * G++ multiple inheritance compiler problem
6243 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6244 inheritance lattices was reworked to properly discover ambiguities. We
6245 recently found an example which causes this new algorithm to fail in a
6246 very subtle way, producing bad debug information for those classes.
6247 The file 'gcc.patch' (in this directory) can be applied to gcc to
6248 circumvent the problem. A future GCC release will contain a complete
6251 The previous G++ debug info problem (mentioned below for the gdb-4.7
6252 release) is fixed in gcc version 2.3.2.
6254 * Improved configure script
6256 The `configure' script will now attempt to guess your system type if
6257 you don't supply a host system type. The old scheme of supplying a
6258 host system triplet is preferable over using this. All the magic is
6259 done in the new `config.guess' script. Examine it for details.
6261 We have also brought our configure script much more in line with the FSF's
6262 version. It now supports the --with-xxx options. In particular,
6263 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6264 The resulting GDB will not be able to read arbitrary object file formats --
6265 only the format ``expected'' to be used on the configured target system.
6266 We hope to make this the default in a future release.
6268 * Documentation improvements
6270 There's new internal documentation on how to modify GDB, and how to
6271 produce clean changes to the code. We implore people to read it
6272 before submitting changes.
6274 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6275 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6276 `info' files are also provided. To build `info' files from scratch,
6277 you will need the latest `makeinfo' release, which will be available in
6278 a future texinfo-X.Y release.
6280 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6281 We're not sure exactly which versions have this problem, but it has
6282 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6283 or better. If that isn't possible, there is a patch in
6284 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6285 around this problem.
6289 GDB now supports array constants that can be used in expressions typed in by
6290 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6291 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6294 The new directory `gdb/sparclite' contains a program that demonstrates
6295 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6297 * New native hosts supported
6299 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6300 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6302 * New targets supported
6304 AMD 29k family via UDI a29k-amd-udi or udi29k
6306 * New file formats supported
6308 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6309 HPUX core files, and SCO 3.2v2 core files.
6313 Attaching to processes now works again; thanks for the many bug reports.
6315 We have also stomped on a bunch of core dumps caused by
6316 printf_filtered("%s") problems.
6318 We eliminated a copyright problem on the rpc and ptrace header files
6319 for VxWorks, which was discovered at the last minute during the 4.7
6320 release. You should now be able to build a VxWorks GDB.
6322 You can now interrupt gdb while an attached process is running. This
6323 will cause the attached process to stop, and give control back to GDB.
6325 We fixed problems caused by using too many file descriptors
6326 for reading symbols from object files and libraries. This was
6327 especially a problem for programs that used many (~100) shared
6330 The `step' command now only enters a subroutine if there is line number
6331 information for the subroutine. Otherwise it acts like the `next'
6332 command. Previously, `step' would enter subroutines if there was
6333 any debugging information about the routine. This avoids problems
6334 when using `cc -g1' on MIPS machines.
6336 * Internal improvements
6338 GDB's internal interfaces have been improved to make it easier to support
6339 debugging of multiple languages in the future.
6341 GDB now uses a common structure for symbol information internally.
6342 Minimal symbols (derived from linkage symbols in object files), partial
6343 symbols (from a quick scan of debug information), and full symbols
6344 contain a common subset of information, making it easier to write
6345 shared code that handles any of them.
6347 * New command line options
6349 We now accept --silent as an alias for --quiet.
6353 The memory-mapped-malloc library is now licensed under the GNU Library
6354 General Public License.
6356 *** Changes in GDB-4.7:
6358 * Host/native/target split
6360 GDB has had some major internal surgery to untangle the support for
6361 hosts and remote targets. Now, when you configure GDB for a remote
6362 target, it will no longer load in all of the support for debugging
6363 local programs on the host. When fully completed and tested, this will
6364 ensure that arbitrary host/target combinations are possible.
6366 The primary conceptual shift is to separate the non-portable code in
6367 GDB into three categories. Host specific code is required any time GDB
6368 is compiled on that host, regardless of the target. Target specific
6369 code relates to the peculiarities of the target, but can be compiled on
6370 any host. Native specific code is everything else: it can only be
6371 built when the host and target are the same system. Child process
6372 handling and core file support are two common `native' examples.
6374 GDB's use of /proc for controlling Unix child processes is now cleaner.
6375 It has been split out into a single module under the `target_ops' vector,
6376 plus two native-dependent functions for each system that uses /proc.
6378 * New hosts supported
6380 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6381 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6382 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6384 * New targets supported
6386 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6387 68030 and CPU32 m68030-*-*, m68332-*-*
6389 * New native hosts supported
6391 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6392 (386bsd is not well tested yet)
6393 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6395 * New file formats supported
6397 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6398 supports reading of `a.out.adobe' object files, which are an a.out
6399 format extended with minimal information about multiple sections.
6403 `show copying' is the same as the old `info copying'.
6404 `show warranty' is the same as `info warrantee'.
6405 These were renamed for consistency. The old commands continue to work.
6407 `info handle' is a new alias for `info signals'.
6409 You can now define pre-command hooks, which attach arbitrary command
6410 scripts to any command. The commands in the hook will be executed
6411 prior to the user's command. You can also create a hook which will be
6412 executed whenever the program stops. See gdb.texinfo.
6416 We now deal with Cfront style name mangling, and can even extract type
6417 info from mangled symbols. GDB can automatically figure out which
6418 symbol mangling style your C++ compiler uses.
6420 Calling of methods and virtual functions has been improved as well.
6424 The crash that occured when debugging Sun Ansi-C compiled binaries is
6425 fixed. This was due to mishandling of the extra N_SO stabs output
6428 We also finally got Ultrix 4.2 running in house, and fixed core file
6429 support, with help from a dozen people on the net.
6431 John M. Farrell discovered that the reason that single-stepping was so
6432 slow on all of the Mips based platforms (primarily SGI and DEC) was
6433 that we were trying to demangle and lookup a symbol used for internal
6434 purposes on every instruction that was being stepped through. Changing
6435 the name of that symbol so that it couldn't be mistaken for a C++
6436 mangled symbol sped things up a great deal.
6438 Rich Pixley sped up symbol lookups in general by getting much smarter
6439 about when C++ symbol mangling is necessary. This should make symbol
6440 completion (TAB on the command line) much faster. It's not as fast as
6441 we'd like, but it's significantly faster than gdb-4.6.
6445 A new user controllable variable 'call_scratch_address' can
6446 specify the location of a scratch area to be used when GDB
6447 calls a function in the target. This is necessary because the
6448 usual method of putting the scratch area on the stack does not work
6449 in systems that have separate instruction and data spaces.
6451 We integrated changes to support the 29k UDI (Universal Debugger
6452 Interface), but discovered at the last minute that we didn't have all
6453 of the appropriate copyright paperwork. We are working with AMD to
6454 resolve this, and hope to have it available soon.
6458 We have sped up the remote serial line protocol, especially for targets
6459 with lots of registers. It now supports a new `expedited status' ('T')
6460 message which can be used in place of the existing 'S' status message.
6461 This allows the remote stub to send only the registers that GDB
6462 needs to make a quick decision about single-stepping or conditional
6463 breakpoints, eliminating the need to fetch the entire register set for
6464 each instruction being stepped through.
6466 The GDB remote serial protocol now implements a write-through cache for
6467 registers, only re-reading the registers if the target has run.
6469 There is also a new remote serial stub for SPARC processors. You can
6470 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6471 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6472 processor with a serial port.
6476 Configure.in files have become much easier to read and modify. A new
6477 `table driven' format makes it more obvious what configurations are
6478 supported, and what files each one uses.
6482 There is a new opcodes library which will eventually contain all of the
6483 disassembly routines and opcode tables. At present, it only contains
6484 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6485 disassembler (binutils/objdump) to share these routines.
6487 The libiberty library is now copylefted under the GNU Library General
6488 Public License. This allows more liberal use, and was done so libg++
6489 can use it. This makes no difference to GDB, since the Library License
6490 grants all the rights from the General Public License.
6494 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6495 reference to the stabs symbol info used by the debugger. It is (as far
6496 as we know) the only published document on this fascinating topic. We
6497 encourage you to read it, compare it to the stabs information on your
6498 system, and send improvements on the document in general (to
6499 bug-gdb@prep.ai.mit.edu).
6501 And, of course, many bugs have been fixed.
6504 *** Changes in GDB-4.6:
6506 * Better support for C++ function names
6508 GDB now accepts as input the "demangled form" of C++ overloaded function
6509 names and member function names, and can do command completion on such names
6510 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6511 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6512 Make use of command completion, it is your friend.
6514 GDB also now accepts a variety of C++ mangled symbol formats. They are
6515 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6516 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6517 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6518 for the list of formats.
6520 * G++ symbol mangling problem
6522 Recent versions of gcc have a bug in how they emit debugging information for
6523 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6524 directory) can be applied to gcc to fix the problem. Alternatively, if you
6525 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6526 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6527 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6530 * New 'maintenance' command
6532 All of the commands related to hacking GDB internals have been moved out of
6533 the main command set, and now live behind the 'maintenance' command. This
6534 can also be abbreviated as 'mt'. The following changes were made:
6536 dump-me -> maintenance dump-me
6537 info all-breakpoints -> maintenance info breakpoints
6538 printmsyms -> maintenance print msyms
6539 printobjfiles -> maintenance print objfiles
6540 printpsyms -> maintenance print psymbols
6541 printsyms -> maintenance print symbols
6543 The following commands are new:
6545 maintenance demangle Call internal GDB demangler routine to
6546 demangle a C++ link name and prints the result.
6547 maintenance print type Print a type chain for a given symbol
6549 * Change to .gdbinit file processing
6551 We now read the $HOME/.gdbinit file before processing the argv arguments
6552 (e.g. reading symbol files or core files). This allows global parameters to
6553 be set, which will apply during the symbol reading. The ./.gdbinit is still
6554 read after argv processing.
6556 * New hosts supported
6558 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6560 GNU/Linux support i386-unknown-linux or linux
6562 We are also including code to support the HP/PA running BSD and HPUX. This
6563 is almost guaranteed not to work, as we didn't have time to test or build it
6564 for this release. We are including it so that the more adventurous (or
6565 masochistic) of you can play with it. We also had major problems with the
6566 fact that the compiler that we got from HP doesn't support the -g option.
6569 * New targets supported
6571 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6573 * More smarts about finding #include files
6575 GDB now remembers the compilation directory for all include files, and for
6576 all files from which C is generated (like yacc and lex sources). This
6577 greatly improves GDB's ability to find yacc/lex sources, and include files,
6578 especially if you are debugging your program from a directory different from
6579 the one that contains your sources.
6581 We also fixed a bug which caused difficulty with listing and setting
6582 breakpoints in include files which contain C code. (In the past, you had to
6583 try twice in order to list an include file that you hadn't looked at before.)
6585 * Interesting infernals change
6587 GDB now deals with arbitrary numbers of sections, where the symbols for each
6588 section must be relocated relative to that section's landing place in the
6589 target's address space. This work was needed to support ELF with embedded
6590 stabs used by Solaris-2.0.
6592 * Bug fixes (of course!)
6594 There have been loads of fixes for the following things:
6595 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6596 i960, stabs, DOS(GO32), procfs, etc...
6598 See the ChangeLog for details.
6600 *** Changes in GDB-4.5:
6602 * New machines supported (host and target)
6604 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6606 SGI Irix-4.x mips-sgi-irix4 or iris4
6608 * New malloc package
6610 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6611 Mmalloc is capable of handling mutiple heaps of memory. It is also
6612 capable of saving a heap to a file, and then mapping it back in later.
6613 This can be used to greatly speedup the startup of GDB by using a
6614 pre-parsed symbol table which lives in a mmalloc managed heap. For
6615 more details, please read mmalloc/mmalloc.texi.
6619 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6620 'help info proc' for details.
6622 * MIPS ecoff symbol table format
6624 The code that reads MIPS symbol table format is now supported on all hosts.
6625 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6628 * File name changes for MS-DOS
6630 Many files in the config directories have been renamed to make it easier to
6631 support GDB on MS-DOSe systems (which have very restrictive file name
6632 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6633 environment) is close to working but has some remaining problems. Note
6634 that debugging of DOS programs is not supported, due to limitations
6635 in the ``operating system'', but it can be used to host cross-debugging.
6637 * Cross byte order fixes
6639 Many fixes have been made to support cross debugging of Sparc and MIPS
6640 targets from hosts whose byte order differs.
6642 * New -mapped and -readnow options
6644 If memory-mapped files are available on your system through the 'mmap'
6645 system call, you can use the -mapped option on the `file' or
6646 `symbol-file' commands to cause GDB to write the symbols from your
6647 program into a reusable file. If the program you are debugging is
6648 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6649 Future GDB debugging sessions will notice the presence of this file,
6650 and will quickly map in symbol information from it, rather than reading
6651 the symbol table from the executable program. Using the '-mapped'
6652 option in a GDB `file' or `symbol-file' command has the same effect as
6653 starting GDB with the '-mapped' command-line option.
6655 You can cause GDB to read the entire symbol table immediately by using
6656 the '-readnow' option with any of the commands that load symbol table
6657 information (or on the GDB command line). This makes the command
6658 slower, but makes future operations faster.
6660 The -mapped and -readnow options are typically combined in order to
6661 build a `fred.syms' file that contains complete symbol information.
6662 A simple GDB invocation to do nothing but build a `.syms' file for future
6665 gdb -batch -nx -mapped -readnow programname
6667 The `.syms' file is specific to the host machine on which GDB is run.
6668 It holds an exact image of GDB's internal symbol table. It cannot be
6669 shared across multiple host platforms.
6671 * longjmp() handling
6673 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6674 siglongjmp() without losing control. This feature has not yet been ported to
6675 all systems. It currently works on many 386 platforms, all MIPS-based
6676 platforms (SGI, DECstation, etc), and Sun3/4.
6680 Preliminary work has been put in to support the new Solaris OS from Sun. At
6681 this time, it can control and debug processes, but it is not capable of
6686 As always, many many bug fixes. The major areas were with g++, and mipsread.
6687 People using the MIPS-based platforms should experience fewer mysterious
6688 crashes and trashed symbol tables.
6690 *** Changes in GDB-4.4:
6692 * New machines supported (host and target)
6694 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6696 BSD Reno on Vax vax-dec-bsd
6697 Ultrix on Vax vax-dec-ultrix
6699 * New machines supported (target)
6701 AMD 29000 embedded, using EBMON a29k-none-none
6705 GDB continues to improve its handling of C++. `References' work better.
6706 The demangler has also been improved, and now deals with symbols mangled as
6707 per the Annotated C++ Reference Guide.
6709 GDB also now handles `stabs' symbol information embedded in MIPS
6710 `ecoff' symbol tables. Since the ecoff format was not easily
6711 extensible to handle new languages such as C++, this appeared to be a
6712 good way to put C++ debugging info into MIPS binaries. This option
6713 will be supported in the GNU C compiler, version 2, when it is
6716 * New features for SVR4
6718 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6719 shared libraries. Debugging dynamically linked programs should present
6720 only minor differences from debugging statically linked programs.
6722 The `info proc' command will print out information about any process
6723 on an SVR4 system (including the one you are debugging). At the moment,
6724 it prints the address mappings of the process.
6726 If you bring up GDB on another SVR4 system, please send mail to
6727 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6729 * Better dynamic linking support in SunOS
6731 Reading symbols from shared libraries which contain debugging symbols
6732 now works properly. However, there remain issues such as automatic
6733 skipping of `transfer vector' code during function calls, which
6734 make it harder to debug code in a shared library, than to debug the
6735 same code linked statically.
6739 GDB is now using the latest `getopt' routines from the FSF. This
6740 version accepts the -- prefix for options with long names. GDB will
6741 continue to accept the old forms (-option and +option) as well.
6742 Various single letter abbreviations for options have been explicity
6743 added to the option table so that they won't get overshadowed in the
6744 future by other options that begin with the same letter.
6748 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6749 Many assorted bugs have been handled. Many more remain to be handled.
6750 See the various ChangeLog files (primarily in gdb and bfd) for details.
6753 *** Changes in GDB-4.3:
6755 * New machines supported (host and target)
6757 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6758 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6759 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6761 * Almost SCO Unix support
6763 We had hoped to support:
6764 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6765 (except for core file support), but we discovered very late in the release
6766 that it has problems with process groups that render gdb unusable. Sorry
6767 about that. I encourage people to fix it and post the fixes.
6769 * Preliminary ELF and DWARF support
6771 GDB can read ELF object files on System V Release 4, and can handle
6772 debugging records for C, in DWARF format, in ELF files. This support
6773 is preliminary. If you bring up GDB on another SVR4 system, please
6774 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6779 GDB now uses the latest `readline' library. One user-visible change
6780 is that two tabs will list possible command completions, which previously
6781 required typing M-? (meta-question mark, or ESC ?).
6785 The `stepi' bug that many of you noticed has been squashed.
6786 Many bugs in C++ have been handled. Many more remain to be handled.
6787 See the various ChangeLog files (primarily in gdb and bfd) for details.
6789 * State of the MIPS world (in case you wondered):
6791 GDB can understand the symbol tables emitted by the compilers
6792 supplied by most vendors of MIPS-based machines, including DEC. These
6793 symbol tables are in a format that essentially nobody else uses.
6795 Some versions of gcc come with an assembler post-processor called
6796 mips-tfile. This program is required if you want to do source-level
6797 debugging of gcc-compiled programs. I believe FSF does not ship
6798 mips-tfile with gcc version 1, but it will eventually come with gcc
6801 Debugging of g++ output remains a problem. g++ version 1.xx does not
6802 really support it at all. (If you're lucky, you should be able to get
6803 line numbers and stack traces to work, but no parameters or local
6804 variables.) With some work it should be possible to improve the
6807 When gcc version 2 is released, you will have somewhat better luck.
6808 However, even then you will get confusing results for inheritance and
6811 We will eventually provide full debugging of g++ output on
6812 DECstations. This will probably involve some kind of stabs-in-ecoff
6813 encapulation, but the details have not been worked out yet.
6816 *** Changes in GDB-4.2:
6818 * Improved configuration
6820 Only one copy of `configure' exists now, and it is not self-modifying.
6821 Porting BFD is simpler.
6825 The `step' and `next' commands now only stop at the first instruction
6826 of a source line. This prevents the multiple stops that used to occur
6827 in switch statements, for-loops, etc. `Step' continues to stop if a
6828 function that has debugging information is called within the line.
6832 Lots of small bugs fixed. More remain.
6834 * New host supported (not target)
6836 Intel 386 PC clone running Mach i386-none-mach
6839 *** Changes in GDB-4.1:
6841 * Multiple source language support
6843 GDB now has internal scaffolding to handle several source languages.
6844 It determines the type of each source file from its filename extension,
6845 and will switch expression parsing and number formatting to match the
6846 language of the function in the currently selected stack frame.
6847 You can also specifically set the language to be used, with
6848 `set language c' or `set language modula-2'.
6852 GDB now has preliminary support for the GNU Modula-2 compiler,
6853 currently under development at the State University of New York at
6854 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6855 continue through the fall of 1991 and into 1992.
6857 Other Modula-2 compilers are currently not supported, and attempting to
6858 debug programs compiled with them will likely result in an error as the
6859 symbol table is read. Feel free to work on it, though!
6861 There are hooks in GDB for strict type checking and range checking,
6862 in the `Modula-2 philosophy', but they do not currently work.
6866 GDB can now write to executable and core files (e.g. patch
6867 a variable's value). You must turn this switch on, specify
6868 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6869 by assigning a new value to a variable. Modifications take
6872 * Automatic SunOS shared library reading
6874 When you run your program, GDB automatically determines where its
6875 shared libraries (if any) have been loaded, and reads their symbols.
6876 The `share' command is no longer needed. This also works when
6877 examining core files.
6881 You can specify the number of lines that the `list' command shows.
6884 * New machines supported (host and target)
6886 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6887 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6888 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6890 * New hosts supported (not targets)
6892 IBM RT/PC: romp-ibm-aix or rtpc
6894 * New targets supported (not hosts)
6896 AMD 29000 embedded with COFF a29k-none-coff
6897 AMD 29000 embedded with a.out a29k-none-aout
6898 Ultracomputer remote kernel debug a29k-nyu-kern
6900 * New remote interfaces
6906 *** Changes in GDB-4.0:
6910 Wide output is wrapped at good places to make the output more readable.
6912 Gdb now supports cross-debugging from a host machine of one type to a
6913 target machine of another type. Communication with the target system
6914 is over serial lines. The ``target'' command handles connecting to the
6915 remote system; the ``load'' command will download a program into the
6916 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6917 also supports debugging of realtime processes running under VxWorks,
6918 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6919 stub on the target system.
6921 New CPUs supported include the AMD 29000 and Intel 960.
6923 GDB now reads object files and symbol tables via a ``binary file''
6924 library, which allows a single copy of GDB to debug programs of multiple
6925 object file types such as a.out and coff.
6927 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6928 refcard.dvi and refcard.ps are available to format it).
6931 * Control-Variable user interface simplified
6933 All variables that control the operation of the debugger can be set
6934 by the ``set'' command, and displayed by the ``show'' command.
6936 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6937 ``Show prompt'' produces the response:
6938 Gdb's prompt is new-gdb=>.
6940 What follows are the NEW set commands. The command ``help set'' will
6941 print a complete list of old and new set commands. ``help set FOO''
6942 will give a longer description of the variable FOO. ``show'' will show
6943 all of the variable descriptions and their current settings.
6945 confirm on/off: Enables warning questions for operations that are
6946 hard to recover from, e.g. rerunning the program while
6947 it is already running. Default is ON.
6949 editing on/off: Enables EMACS style command line editing
6950 of input. Previous lines can be recalled with
6951 control-P, the current line can be edited with control-B,
6952 you can search for commands with control-R, etc.
6955 history filename NAME: NAME is where the gdb command history
6956 will be stored. The default is .gdb_history,
6957 or the value of the environment variable
6960 history size N: The size, in commands, of the command history. The
6961 default is 256, or the value of the environment variable
6964 history save on/off: If this value is set to ON, the history file will
6965 be saved after exiting gdb. If set to OFF, the
6966 file will not be saved. The default is OFF.
6968 history expansion on/off: If this value is set to ON, then csh-like
6969 history expansion will be performed on
6970 command line input. The default is OFF.
6972 radix N: Sets the default radix for input and output. It can be set
6973 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6974 in the current radix, so "set radix 10" is always a no-op.
6976 height N: This integer value is the number of lines on a page. Default
6977 is 24, the current `stty rows'' setting, or the ``li#''
6978 setting from the termcap entry matching the environment
6981 width N: This integer value is the number of characters on a line.
6982 Default is 80, the current `stty cols'' setting, or the ``co#''
6983 setting from the termcap entry matching the environment
6986 Note: ``set screensize'' is obsolete. Use ``set height'' and
6987 ``set width'' instead.
6989 print address on/off: Print memory addresses in various command displays,
6990 such as stack traces and structure values. Gdb looks
6991 more ``symbolic'' if you turn this off; it looks more
6992 ``machine level'' with it on. Default is ON.
6994 print array on/off: Prettyprint arrays. New convenient format! Default
6997 print demangle on/off: Print C++ symbols in "source" form if on,
7000 print asm-demangle on/off: Same, for assembler level printouts
7003 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7006 * Support for Epoch Environment.
7008 The epoch environment is a version of Emacs v18 with windowing. One
7009 new command, ``inspect'', is identical to ``print'', except that if you
7010 are running in the epoch environment, the value is printed in its own
7014 * Support for Shared Libraries
7016 GDB can now debug programs and core files that use SunOS shared libraries.
7017 Symbols from a shared library cannot be referenced
7018 before the shared library has been linked with the program (this
7019 happens after you type ``run'' and before the function main() is entered).
7020 At any time after this linking (including when examining core files
7021 from dynamically linked programs), gdb reads the symbols from each
7022 shared library when you type the ``sharedlibrary'' command.
7023 It can be abbreviated ``share''.
7025 sharedlibrary REGEXP: Load shared object library symbols for files
7026 matching a unix regular expression. No argument
7027 indicates to load symbols for all shared libraries.
7029 info sharedlibrary: Status of loaded shared libraries.
7034 A watchpoint stops execution of a program whenever the value of an
7035 expression changes. Checking for this slows down execution
7036 tremendously whenever you are in the scope of the expression, but is
7037 quite useful for catching tough ``bit-spreader'' or pointer misuse
7038 problems. Some machines such as the 386 have hardware for doing this
7039 more quickly, and future versions of gdb will use this hardware.
7041 watch EXP: Set a watchpoint (breakpoint) for an expression.
7043 info watchpoints: Information about your watchpoints.
7045 delete N: Deletes watchpoint number N (same as breakpoints).
7046 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7047 enable N: Re-enables watchpoint number N (same as breakpoints).
7050 * C++ multiple inheritance
7052 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7055 * C++ exception handling
7057 Gdb now supports limited C++ exception handling. Besides the existing
7058 ability to breakpoint on an exception handler, gdb can breakpoint on
7059 the raising of an exception (before the stack is peeled back to the
7062 catch FOO: If there is a FOO exception handler in the dynamic scope,
7063 set a breakpoint to catch exceptions which may be raised there.
7064 Multiple exceptions (``catch foo bar baz'') may be caught.
7066 info catch: Lists all exceptions which may be caught in the
7067 current stack frame.
7070 * Minor command changes
7072 The command ``call func (arg, arg, ...)'' now acts like the print
7073 command, except it does not print or save a value if the function's result
7074 is void. This is similar to dbx usage.
7076 The ``up'' and ``down'' commands now always print the frame they end up
7077 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7078 frames without printing.
7080 * New directory command
7082 'dir' now adds directories to the FRONT of the source search path.
7083 The path starts off empty. Source files that contain debug information
7084 about the directory in which they were compiled can be found even
7085 with an empty path; Sun CC and GCC include this information. If GDB can't
7086 find your source file in the current directory, type "dir .".
7088 * Configuring GDB for compilation
7090 For normal use, type ``./configure host''. See README or gdb.texinfo
7093 GDB now handles cross debugging. If you are remotely debugging between
7094 two different machines, type ``./configure host -target=targ''.
7095 Host is the machine where GDB will run; targ is the machine
7096 where the program that you are debugging will run.