1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB now has experimental support for the compilation and injection of
7 C++ source code into the inferior. This beta release does not include
8 support for several language features, such as templates, constructors,
11 This feature requires GCC 7.1 or higher built with libcp1.so
14 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
15 can be passed using the '[ADDRESS]:PORT' notation, or the regular
16 'ADDRESS:PORT' method.
18 * DWARF index cache: GDB can now automatically save indices of DWARF
19 symbols on disk to speed up further loading of the same binaries.
21 * GDB in batch mode now exits with status 1 if the last command to be
26 set debug compile-cplus-types
27 show debug compile-cplus-types
28 Control the display of debug output about type conversion in the
29 C++ compile feature. Commands have no effect while compiliong
34 Control whether debug output about files/functions skipping is
37 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
38 Apply a command to some frames.
39 FLAG arguments allow to control what output to produce and how to handle
40 errors raised when applying COMMAND to a frame.
43 Apply a command to all threads (ignoring errors and empty output).
44 Shortcut for 'thread apply all -s COMMAND'.
47 Apply a command to all frames (ignoring errors and empty output).
48 Shortcut for 'frame apply all -s COMMAND'.
51 Apply a command to all frames of all threads (ignoring errors and empty
53 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
55 maint set dwarf unwinders (on|off)
56 maint show dwarf unwinders
57 Control whether DWARF unwinders can be used.
60 Display a list of open files for a process.
64 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
65 The 'thread apply' command accepts new FLAG arguments.
66 FLAG arguments allow to control what output to produce and how to handle
67 errors raised when applying COMMAND to a thread.
71 ** The '-data-disassemble' MI command now accepts an '-a' option to
72 disassemble the whole function surrounding the given program
73 counter value or function name. Support for this feature can be
74 verified by using the "-list-features" command, which should
75 contain "data-disassemble-a-option".
77 ** Command responses and notifications that include a frame now include
78 the frame's architecture in a new "arch" attribute.
80 * New native configurations
82 GNU/Linux/RISC-V riscv*-*-linux*
86 GNU/Linux/RISC-V riscv*-*-linux*
88 CSKY GNU/LINUX csky*-*-linux
92 ** The gdb.Inferior type has a new 'progspace' property, which is the program
93 space associated to that inferior.
95 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
96 of objfiles associated to that program space.
98 *** Changes in GDB 8.2
100 * The 'set disassembler-options' command now supports specifying options
103 * The 'symbol-file' command now accepts an '-o' option to add a relative
104 offset to all sections.
106 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
107 a relative offset to all sections, but it allows to override the load
108 address of individual sections using '-s'.
110 * The 'add-symbol-file' command no longer requires the second argument
111 (address of the text section).
113 * The endianness used with the 'set endian auto' mode in the absence of
114 an executable selected for debugging is now the last endianness chosen
115 either by one of the 'set endian big' and 'set endian little' commands
116 or by inferring from the last executable used, rather than the startup
119 * The pager now allows a "c" response, meaning to disable the pager
120 for the rest of the current command.
122 * The commands 'info variables/functions/types' now show the source line
123 numbers of symbol definitions when available.
125 * 'info proc' now works on running processes on FreeBSD systems and core
126 files created on FreeBSD systems.
128 * C expressions can now use _Alignof, and C++ expressions can now use
131 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
132 the vector length while the process is running.
138 Control display of debugging info regarding the FreeBSD native target.
140 set|show varsize-limit
141 This new setting allows the user to control the maximum size of Ada
142 objects being printed when those objects have a variable type,
143 instead of that maximum size being hardcoded to 65536 bytes.
145 set|show record btrace cpu
146 Controls the processor to be used for enabling errata workarounds for
149 maint check libthread-db
150 Run integrity checks on the current inferior's thread debugging
153 maint set check-libthread-db (on|off)
154 maint show check-libthread-db
155 Control whether to run integrity checks on inferior specific thread
156 debugging libraries as they are loaded. The default is not to
161 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
163 ** The commands attached to a breakpoint can be set by assigning to
164 the breakpoint's "commands" field.
166 ** gdb.execute can now execute multi-line gdb commands.
168 ** The new functions gdb.convenience_variable and
169 gdb.set_convenience_variable can be used to get and set the value
170 of convenience variables.
172 ** A gdb.Parameter will no longer print the "set" help text on an
173 ordinary "set"; instead by default a "set" will be silent unless
174 the get_set_string method returns a non-empty string.
178 RiscV ELF riscv*-*-elf
180 * Removed targets and native configurations
182 m88k running OpenBSD m88*-*-openbsd*
183 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
184 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
185 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
187 * Aarch64/Linux hardware watchpoints improvements
189 Hardware watchpoints on unaligned addresses are now properly
190 supported when running Linux kernel 4.10 or higher: read and access
191 watchpoints are no longer spuriously missed, and all watchpoints
192 lengths between 1 and 8 bytes are supported. On older kernels,
193 watchpoints set on unaligned addresses are no longer missed, with
194 the tradeoff that there is a possibility of false hits being
199 --enable-codesign=CERT
200 This can be used to invoke "codesign -s CERT" after building gdb.
201 This option is useful on macOS, where code signing is required for
202 gdb to work properly.
204 --disable-gdbcli has been removed
205 This is now silently accepted, but does nothing.
207 *** Changes in GDB 8.1
209 * GDB now supports dynamically creating arbitrary register groups specified
210 in XML target descriptions. This allows for finer grain grouping of
211 registers on systems with a large amount of registers.
213 * The 'ptype' command now accepts a '/o' flag, which prints the
214 offsets and sizes of fields in a struct, like the pahole(1) tool.
216 * New "--readnever" command line option instructs GDB to not read each
217 symbol file's symbolic debug information. This makes startup faster
218 but at the expense of not being able to perform symbolic debugging.
219 This option is intended for use cases where symbolic debugging will
220 not be used, e.g., when you only need to dump the debuggee's core.
222 * GDB now uses the GNU MPFR library, if available, to emulate target
223 floating-point arithmetic during expression evaluation when the target
224 uses different floating-point formats than the host. At least version
225 3.1 of GNU MPFR is required.
227 * GDB now supports access to the guarded-storage-control registers and the
228 software-based guarded-storage broadcast control registers on IBM z14.
230 * On Unix systems, GDB now supports transmitting environment variables
231 that are to be set or unset to GDBserver. These variables will
232 affect the environment to be passed to the remote inferior.
234 To inform GDB of environment variables that are to be transmitted to
235 GDBserver, use the "set environment" command. Only user set
236 environment variables are sent to GDBserver.
238 To inform GDB of environment variables that are to be unset before
239 the remote inferior is started by the GDBserver, use the "unset
240 environment" command.
242 * Completion improvements
244 ** GDB can now complete function parameters in linespecs and
245 explicit locations without quoting. When setting breakpoints,
246 quoting around functions names to help with TAB-completion is
247 generally no longer necessary. For example, this now completes
250 (gdb) b function(in[TAB]
251 (gdb) b function(int)
253 Related, GDB is no longer confused with completing functions in
254 C++ anonymous namespaces:
257 (gdb) b (anonymous namespace)::[TAB][TAB]
258 (anonymous namespace)::a_function()
259 (anonymous namespace)::b_function()
261 ** GDB now has much improved linespec and explicit locations TAB
262 completion support, that better understands what you're
263 completing and offers better suggestions. For example, GDB no
264 longer offers data symbols as possible completions when you're
265 setting a breakpoint.
267 ** GDB now TAB-completes label symbol names.
269 ** The "complete" command now mimics TAB completion accurately.
271 * New command line options (gcore)
274 Dump all memory mappings.
276 * Breakpoints on C++ functions are now set on all scopes by default
278 By default, breakpoints on functions/methods are now interpreted as
279 specifying all functions with the given name ignoring missing
280 leading scopes (namespaces and classes).
282 For example, assuming a C++ program with symbols named:
287 both commands "break func()" and "break B::func()" set a breakpoint
290 You can use the new flag "-qualified" to override this. This makes
291 GDB interpret the specified function name as a complete
292 fully-qualified name instead. For example, using the same C++
293 program, the "break -q B::func" command sets a breakpoint on
294 "B::func", only. A parameter has been added to the Python
295 gdb.Breakpoint constructor to achieve the same result when creating
296 a breakpoint from Python.
298 * Breakpoints on functions marked with C++ ABI tags
300 GDB can now set breakpoints on functions marked with C++ ABI tags
301 (e.g., [abi:cxx11]). See here for a description of ABI tags:
302 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
304 Functions with a C++11 abi tag are demangled/displayed like this:
306 function[abi:cxx11](int)
309 You can now set a breakpoint on such functions simply as if they had
312 (gdb) b function(int)
314 Or if you need to disambiguate between tags, like:
316 (gdb) b function[abi:other_tag](int)
318 Tab completion was adjusted accordingly as well.
322 ** New events gdb.new_inferior, gdb.inferior_deleted, and
323 gdb.new_thread are emitted. See the manual for further
324 description of these.
326 ** A new function, "gdb.rbreak" has been added to the Python API.
327 This function allows the setting of a large number of breakpoints
328 via a regex pattern in Python. See the manual for further details.
330 ** Python breakpoints can now accept explicit locations. See the
331 manual for a further description of this feature.
334 * New features in the GDB remote stub, GDBserver
336 ** GDBserver is now able to start inferior processes with a
337 specified initial working directory.
339 The user can set the desired working directory to be used from
340 GDB using the new "set cwd" command.
342 ** New "--selftest" command line option runs some GDBserver self
343 tests. These self tests are disabled in releases.
345 ** On Unix systems, GDBserver now does globbing expansion and variable
346 substitution in inferior command line arguments.
348 This is done by starting inferiors using a shell, like GDB does.
349 See "set startup-with-shell" in the user manual for how to disable
350 this from GDB when using "target extended-remote". When using
351 "target remote", you can disable the startup with shell by using the
352 new "--no-startup-with-shell" GDBserver command line option.
354 ** On Unix systems, GDBserver now supports receiving environment
355 variables that are to be set or unset from GDB. These variables
356 will affect the environment to be passed to the inferior.
358 * When catching an Ada exception raised with a message, GDB now prints
359 the message in the catchpoint hit notification. In GDB/MI mode, that
360 information is provided as an extra field named "exception-message"
361 in the *stopped notification.
363 * Trait objects can now be inspected When debugging Rust code. This
364 requires compiler support which will appear in Rust 1.24.
368 QEnvironmentHexEncoded
369 Inform GDBserver of an environment variable that is to be passed to
370 the inferior when starting it.
373 Inform GDBserver of an environment variable that is to be unset
374 before starting the remote inferior.
377 Inform GDBserver that the environment should be reset (i.e.,
378 user-set environment variables should be unset).
381 Indicates whether the inferior must be started with a shell or not.
384 Tell GDBserver that the inferior to be started should use a specific
387 * The "maintenance print c-tdesc" command now takes an optional
388 argument which is the file name of XML target description.
390 * The "maintenance selftest" command now takes an optional argument to
391 filter the tests to be run.
393 * The "enable", and "disable" commands now accept a range of
394 breakpoint locations, e.g. "enable 1.3-5".
399 Set and show the current working directory for the inferior.
402 Set and show compilation command used for compiling and injecting code
403 with the 'compile' commands.
405 set debug separate-debug-file
406 show debug separate-debug-file
407 Control the display of debug output about separate debug file search.
409 set dump-excluded-mappings
410 show dump-excluded-mappings
411 Control whether mappings marked with the VM_DONTDUMP flag should be
412 dumped when generating a core file.
415 List the registered selftests.
418 Start the debugged program stopping at the first instruction.
421 Control display of debugging messages related to OpenRISC targets.
423 set|show print type nested-type-limit
424 Set and show the limit of nesting level for nested types that the
425 type printer will show.
427 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
430 * Safer/improved support for debugging with no debug info
432 GDB no longer assumes functions with no debug information return
435 This means that GDB now refuses to call such functions unless you
436 tell it the function's type, by either casting the call to the
437 declared return type, or by casting the function to a function
438 pointer of the right type, and calling that:
440 (gdb) p getenv ("PATH")
441 'getenv' has unknown return type; cast the call to its declared return type
442 (gdb) p (char *) getenv ("PATH")
443 $1 = 0x7fffffffe "/usr/local/bin:/"...
444 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
445 $2 = 0x7fffffffe "/usr/local/bin:/"...
447 Similarly, GDB no longer assumes that global variables with no debug
448 info have type 'int', and refuses to print the variable's value
449 unless you tell it the variable's type:
452 'var' has unknown type; cast it to its declared type
456 * New native configurations
458 FreeBSD/aarch64 aarch64*-*-freebsd*
459 FreeBSD/arm arm*-*-freebsd*
463 FreeBSD/aarch64 aarch64*-*-freebsd*
464 FreeBSD/arm arm*-*-freebsd*
465 OpenRISC ELF or1k*-*-elf
467 * Removed targets and native configurations
469 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
471 *** Changes in GDB 8.0
473 * GDB now supports access to the PKU register on GNU/Linux. The register is
474 added by the Memory Protection Keys for Userspace feature which will be
475 available in future Intel CPUs.
477 * GDB now supports C++11 rvalue references.
481 ** New functions to start, stop and access a running btrace recording.
482 ** Rvalue references are now supported in gdb.Type.
484 * GDB now supports recording and replaying rdrand and rdseed Intel 64
487 * Building GDB and GDBserver now requires a C++11 compiler.
489 For example, GCC 4.8 or later.
491 It is no longer possible to build GDB or GDBserver with a C
492 compiler. The --disable-build-with-cxx configure option has been
495 * Building GDB and GDBserver now requires GNU make >= 3.81.
497 It is no longer supported to build GDB or GDBserver with another
498 implementation of the make program or an earlier version of GNU make.
500 * Native debugging on MS-Windows supports command-line redirection
502 Command-line arguments used for starting programs on MS-Windows can
503 now include redirection symbols supported by native Windows shells,
504 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
505 as "run", "start", and "set args", as well as the corresponding MI
508 * Support for thread names on MS-Windows.
510 GDB now catches and handles the special exception that programs
511 running on MS-Windows use to assign names to threads in the
514 * Support for Java programs compiled with gcj has been removed.
516 * User commands now accept an unlimited number of arguments.
517 Previously, only up to 10 was accepted.
519 * The "eval" command now expands user-defined command arguments.
521 This makes it easier to process a variable number of arguments:
526 eval "print $arg%d", $i
531 * Target descriptions can now describe registers for sparc32 and sparc64.
533 * GDB now supports DWARF version 5 (debug information format).
534 Its .debug_names index is not yet supported.
536 * New native configurations
538 FreeBSD/mips mips*-*-freebsd
542 Synopsys ARC arc*-*-elf32
543 FreeBSD/mips mips*-*-freebsd
545 * Removed targets and native configurations
547 Alpha running FreeBSD alpha*-*-freebsd*
548 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
553 Erases all the flash memory regions reported by the target.
555 maint print arc arc-instruction address
556 Print internal disassembler information about instruction at a given address.
560 set disassembler-options
561 show disassembler-options
562 Controls the passing of target specific information to the disassembler.
563 If it is necessary to specify more than one disassembler option then
564 multiple options can be placed together into a comma separated list.
565 The default value is the empty string. Currently, the only supported
566 targets are ARM, PowerPC and S/390.
571 Erases all the flash memory regions reported by the target. This is
572 equivalent to the CLI command flash-erase.
574 -file-list-shared-libraries
575 List the shared libraries in the program. This is
576 equivalent to the CLI command "info shared".
579 Catchpoints stopping the program when Ada exceptions are
580 handled. This is equivalent to the CLI command "catch handlers".
582 *** Changes in GDB 7.12
584 * GDB and GDBserver now build with a C++ compiler by default.
586 The --enable-build-with-cxx configure option is now enabled by
587 default. One must now explicitly configure with
588 --disable-build-with-cxx in order to build with a C compiler. This
589 option will be removed in a future release.
591 * GDBserver now supports recording btrace without maintaining an active
594 * GDB now supports a negative repeat count in the 'x' command to examine
595 memory backward from the given address. For example:
598 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
599 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
600 (gdb) x/-5i 0x0000000000400580
601 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
602 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
603 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
604 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
605 0x40057b <main(int, char**)+25>:
606 callq 0x400536 <Func1(int, char const*)>
608 * Fortran: Support structures with fields of dynamic types and
609 arrays of dynamic types.
611 * The symbol dumping maintenance commands have new syntax.
612 maint print symbols [-pc address] [--] [filename]
613 maint print symbols [-objfile objfile] [-source source] [--] [filename]
614 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
615 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
616 maint print msymbols [-objfile objfile] [--] [filename]
618 * GDB now supports multibit bitfields and enums in target register
621 * New Python-based convenience function $_as_string(val), which returns
622 the textual representation of a value. This function is especially
623 useful to obtain the text label of an enum value.
625 * Intel MPX bound violation handling.
627 Segmentation faults caused by a Intel MPX boundary violation
628 now display the kind of violation (upper or lower), the memory
629 address accessed and the memory bounds, along with the usual
630 signal received and code location.
634 Program received signal SIGSEGV, Segmentation fault
635 Upper bound violation while accessing address 0x7fffffffc3b3
636 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
637 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
639 * Rust language support.
640 GDB now supports debugging programs written in the Rust programming
641 language. See https://www.rust-lang.org/ for more information about
644 * Support for running interpreters on specified input/output devices
646 GDB now supports a new mechanism that allows frontends to provide
647 fully featured GDB console views, as a better alternative to
648 building such views on top of the "-interpreter-exec console"
649 command. See the new "new-ui" command below. With that command,
650 frontends can now start GDB in the traditional command-line mode
651 running in an embedded terminal emulator widget, and create a
652 separate MI interpreter running on a specified i/o device. In this
653 way, GDB handles line editing, history, tab completion, etc. in the
654 console all by itself, and the GUI uses the separate MI interpreter
655 for its own control and synchronization, invisible to the command
658 * The "catch syscall" command catches groups of related syscalls.
660 The "catch syscall" command now supports catching a group of related
661 syscalls using the 'group:' or 'g:' prefix.
666 skip -gfile file-glob-pattern
667 skip -function function
668 skip -rfunction regular-expression
669 A generalized form of the skip command, with new support for
670 glob-style file names and regular expressions for function names.
671 Additionally, a file spec and a function spec may now be combined.
673 maint info line-table REGEXP
674 Display the contents of GDB's internal line table data struture.
677 Run any GDB unit tests that were compiled in.
680 Start a new user interface instance running INTERP as interpreter,
681 using the TTY file for input/output.
685 ** gdb.Breakpoint objects have a new attribute "pending", which
686 indicates whether the breakpoint is pending.
687 ** Three new breakpoint-related events have been added:
688 gdb.breakpoint_created, gdb.breakpoint_modified, and
689 gdb.breakpoint_deleted.
692 Signal ("set") the given MS-Windows event object. This is used in
693 conjunction with the Windows JIT debugging (AeDebug) support, where
694 the OS suspends a crashing process until a debugger can attach to
695 it. Resuming the crashing process, in order to debug it, is done by
698 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
699 was added in GDBserver, including JIT compiling fast tracepoint's
700 conditional expression bytecode into native code.
702 * Support for various remote target protocols and ROM monitors has
705 target m32rsdi Remote M32R debugging over SDI
706 target mips MIPS remote debugging protocol
707 target pmon PMON ROM monitor
708 target ddb NEC's DDB variant of PMON for Vr4300
709 target rockhopper NEC RockHopper variant of PMON
710 target lsi LSI variant of PMO
712 * Support for tracepoints and fast tracepoints on powerpc-linux,
713 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
714 including JIT compiling fast tracepoint's conditional expression
715 bytecode into native code.
717 * MI async record =record-started now includes the method and format used for
718 recording. For example:
720 =record-started,thread-group="i1",method="btrace",format="bts"
722 * MI async record =thread-selected now includes the frame field. For example:
724 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
728 Andes NDS32 nds32*-*-elf
730 *** Changes in GDB 7.11
732 * GDB now supports debugging kernel-based threads on FreeBSD.
734 * Per-inferior thread numbers
736 Thread numbers are now per inferior instead of global. If you're
737 debugging multiple inferiors, GDB displays thread IDs using a
738 qualified INF_NUM.THR_NUM form. For example:
742 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
743 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
744 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
745 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
747 As consequence, thread numbers as visible in the $_thread
748 convenience variable and in Python's InferiorThread.num attribute
749 are no longer unique between inferiors.
751 GDB now maintains a second thread ID per thread, referred to as the
752 global thread ID, which is the new equivalent of thread numbers in
753 previous releases. See also $_gthread below.
755 For backwards compatibility, MI's thread IDs always refer to global
758 * Commands that accept thread IDs now accept the qualified
759 INF_NUM.THR_NUM form as well. For example:
762 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
765 * In commands that accept a list of thread IDs, you can now refer to
766 all threads of an inferior using a star wildcard. GDB accepts
767 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
768 refer to all threads of the current inferior. For example, "info
771 * You can use "info threads -gid" to display the global thread ID of
774 * The new convenience variable $_gthread holds the global number of
777 * The new convenience variable $_inferior holds the number of the
780 * GDB now displays the ID and name of the thread that hit a breakpoint
781 or received a signal, if your program is multi-threaded. For
784 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
785 Thread 1 "main" received signal SIGINT, Interrupt.
787 * Record btrace now supports non-stop mode.
789 * Support for tracepoints on aarch64-linux was added in GDBserver.
791 * The 'record instruction-history' command now indicates speculative execution
792 when using the Intel Processor Trace recording format.
794 * GDB now allows users to specify explicit locations, bypassing
795 the linespec parser. This feature is also available to GDB/MI
798 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
799 GDB now is able to debug both AArch64 applications and ARM applications
802 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
803 including JIT compiling fast tracepoint's conditional expression bytecode
806 * GDB now supports displaced stepping on AArch64 GNU/Linux.
808 * "info threads", "info inferiors", "info display", "info checkpoints"
809 and "maint info program-spaces" now list the corresponding items in
810 ascending ID order, for consistency with all other "info" commands.
812 * In Ada, the overloads selection menu has been enhanced to display the
813 parameter types and the return types for the matching overloaded subprograms.
817 maint set target-non-stop (on|off|auto)
818 maint show target-non-stop
819 Control whether GDB targets always operate in non-stop mode even if
820 "set non-stop" is "off". The default is "auto", meaning non-stop
821 mode is enabled if supported by the target.
823 maint set bfd-sharing
824 maint show bfd-sharing
825 Control the reuse of bfd objects.
829 Control display of debugging info regarding bfd caching.
833 Control display of debugging info regarding FreeBSD threads.
835 set remote multiprocess-extensions-packet
836 show remote multiprocess-extensions-packet
837 Set/show the use of the remote protocol multiprocess extensions.
839 set remote thread-events
840 show remote thread-events
841 Set/show the use of thread create/exit events.
843 set ada print-signatures on|off
844 show ada print-signatures"
845 Control whether parameter types and return types are displayed in overloads
846 selection menus. It is activaled (@code{on}) by default.
850 Controls the maximum size of memory, in bytes, that GDB will
851 allocate for value contents. Prevents incorrect programs from
852 causing GDB to allocate overly large buffers. Default is 64k.
854 * The "disassemble" command accepts a new modifier: /s.
855 It prints mixed source+disassembly like /m with two differences:
856 - disassembled instructions are now printed in program order, and
857 - and source for all relevant files is now printed.
858 The "/m" option is now considered deprecated: its "source-centric"
859 output hasn't proved useful in practice.
861 * The "record instruction-history" command accepts a new modifier: /s.
862 It behaves exactly like /m and prints mixed source+disassembly.
864 * The "set scheduler-locking" command supports a new mode "replay".
865 It behaves like "off" in record mode and like "on" in replay mode.
867 * Support for various ROM monitors has been removed:
869 target dbug dBUG ROM monitor for Motorola ColdFire
870 target picobug Motorola picobug monitor
871 target dink32 DINK32 ROM monitor for PowerPC
872 target m32r Renesas M32R/D ROM monitor
873 target mon2000 mon2000 ROM monitor
874 target ppcbug PPCBUG ROM monitor for PowerPC
876 * Support for reading/writing memory and extracting values on architectures
877 whose memory is addressable in units of any integral multiple of 8 bits.
880 Allows to break when an Ada exception is handled.
885 Indicates that an exec system call was executed.
887 exec-events feature in qSupported
888 The qSupported packet allows GDB to request support for exec
889 events using the new 'gdbfeature' exec-event, and the qSupported
890 response can contain the corresponding 'stubfeature'. Set and
891 show commands can be used to display whether these features are enabled.
894 Equivalent to interrupting with the ^C character, but works in
897 thread created stop reason (T05 create:...)
898 Indicates that the thread was just created and is stopped at entry.
900 thread exit stop reply (w exitcode;tid)
901 Indicates that the thread has terminated.
904 Enables/disables thread create and exit event reporting. For
905 example, this is used in non-stop mode when GDB stops a set of
906 threads and synchronously waits for the their corresponding stop
907 replies. Without exit events, if one of the threads exits, GDB
908 would hang forever not knowing that it should no longer expect a
909 stop for that same thread.
912 Indicates that there are no resumed threads left in the target (all
913 threads are stopped). The remote stub reports support for this stop
914 reply to GDB's qSupported query.
917 Enables/disables catching syscalls from the inferior process.
918 The remote stub reports support for this packet to GDB's qSupported query.
920 syscall_entry stop reason
921 Indicates that a syscall was just called.
923 syscall_return stop reason
924 Indicates that a syscall just returned.
926 * Extended-remote exec events
928 ** GDB now has support for exec events on extended-remote Linux targets.
929 For such targets with Linux kernels 2.5.46 and later, this enables
930 follow-exec-mode and exec catchpoints.
932 set remote exec-event-feature-packet
933 show remote exec-event-feature-packet
934 Set/show the use of the remote exec event feature.
936 * Thread names in remote protocol
938 The reply to qXfer:threads:read may now include a name attribute for each
941 * Target remote mode fork and exec events
943 ** GDB now has support for fork and exec events on target remote mode
944 Linux targets. For such targets with Linux kernels 2.5.46 and later,
945 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
946 fork and exec catchpoints.
948 * Remote syscall events
950 ** GDB now has support for catch syscall on remote Linux targets,
951 currently enabled on x86/x86_64 architectures.
953 set remote catch-syscall-packet
954 show remote catch-syscall-packet
955 Set/show the use of the remote catch syscall feature.
959 ** The -var-set-format command now accepts the zero-hexadecimal
960 format. It outputs data in hexadecimal format with zero-padding on the
965 ** gdb.InferiorThread objects have a new attribute "global_num",
966 which refers to the thread's global thread ID. The existing
967 "num" attribute now refers to the thread's per-inferior number.
968 See "Per-inferior thread numbers" above.
969 ** gdb.InferiorThread objects have a new attribute "inferior", which
970 is the Inferior object the thread belongs to.
972 *** Changes in GDB 7.10
974 * Support for process record-replay and reverse debugging on aarch64*-linux*
975 targets has been added. GDB now supports recording of A64 instruction set
976 including advance SIMD instructions.
978 * Support for Sun's version of the "stabs" debug file format has been removed.
980 * GDB now honors the content of the file /proc/PID/coredump_filter
981 (PID is the process ID) on GNU/Linux systems. This file can be used
982 to specify the types of memory mappings that will be included in a
983 corefile. For more information, please refer to the manual page of
984 "core(5)". GDB also has a new command: "set use-coredump-filter
985 on|off". It allows to set whether GDB will read the content of the
986 /proc/PID/coredump_filter file when generating a corefile.
988 * The "info os" command on GNU/Linux can now display information on
990 "info os cpus" Listing of all cpus/cores on the system
992 * GDB has two new commands: "set serial parity odd|even|none" and
993 "show serial parity". These allows to set or show parity for the
996 * The "info source" command now displays the producer string if it was
997 present in the debug info. This typically includes the compiler version
998 and may include things like its command line arguments.
1000 * The "info dll", an alias of the "info sharedlibrary" command,
1001 is now available on all platforms.
1003 * Directory names supplied to the "set sysroot" commands may be
1004 prefixed with "target:" to tell GDB to access shared libraries from
1005 the target system, be it local or remote. This replaces the prefix
1006 "remote:". The default sysroot has been changed from "" to
1007 "target:". "remote:" is automatically converted to "target:" for
1008 backward compatibility.
1010 * The system root specified by "set sysroot" will be prepended to the
1011 filename of the main executable (if reported to GDB as absolute by
1012 the operating system) when starting processes remotely, and when
1013 attaching to already-running local or remote processes.
1015 * GDB now supports automatic location and retrieval of executable
1016 files from remote targets. Remote debugging can now be initiated
1017 using only a "target remote" or "target extended-remote" command
1018 (no "set sysroot" or "file" commands are required). See "New remote
1021 * The "dump" command now supports verilog hex format.
1023 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1025 * On GNU/Linux, GDB and gdbserver are now able to access executable
1026 and shared library files without a "set sysroot" command when
1027 attaching to processes running in different mount namespaces from
1028 the debugger. This makes it possible to attach to processes in
1029 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1030 See "New remote packets" below.
1032 * The "tui reg" command now provides completion for all of the
1033 available register groups, including target specific groups.
1035 * The HISTSIZE environment variable is no longer read when determining
1036 the size of GDB's command history. GDB now instead reads the dedicated
1037 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1038 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1043 ** Memory ports can now be unbuffered.
1047 ** gdb.Objfile objects have a new attribute "username",
1048 which is the name of the objfile as specified by the user,
1049 without, for example, resolving symlinks.
1050 ** You can now write frame unwinders in Python.
1051 ** gdb.Type objects have a new method "optimized_out",
1052 returning optimized out gdb.Value instance of this type.
1053 ** gdb.Value objects have new methods "reference_value" and
1054 "const_value" which return a reference to the value and a
1055 "const" version of the value respectively.
1059 maint print symbol-cache
1060 Print the contents of the symbol cache.
1062 maint print symbol-cache-statistics
1063 Print statistics of symbol cache usage.
1065 maint flush-symbol-cache
1066 Flush the contents of the symbol cache.
1070 Start branch trace recording using Branch Trace Store (BTS) format.
1073 Evaluate expression by using the compiler and print result.
1077 Explicit commands for enabling and disabling tui mode.
1080 set mpx bound on i386 and amd64
1081 Support for bound table investigation on Intel MPX enabled applications.
1085 Start branch trace recording using Intel Processor Trace format.
1088 Print information about branch tracing internals.
1090 maint btrace packet-history
1091 Print the raw branch tracing data.
1093 maint btrace clear-packet-history
1094 Discard the stored raw branch tracing data.
1097 Discard all branch tracing data. It will be fetched and processed
1098 anew by the next "record" command.
1103 Renamed from "set debug dwarf2-die".
1104 show debug dwarf-die
1105 Renamed from "show debug dwarf2-die".
1107 set debug dwarf-read
1108 Renamed from "set debug dwarf2-read".
1109 show debug dwarf-read
1110 Renamed from "show debug dwarf2-read".
1112 maint set dwarf always-disassemble
1113 Renamed from "maint set dwarf2 always-disassemble".
1114 maint show dwarf always-disassemble
1115 Renamed from "maint show dwarf2 always-disassemble".
1117 maint set dwarf max-cache-age
1118 Renamed from "maint set dwarf2 max-cache-age".
1119 maint show dwarf max-cache-age
1120 Renamed from "maint show dwarf2 max-cache-age".
1122 set debug dwarf-line
1123 show debug dwarf-line
1124 Control display of debugging info regarding DWARF line processing.
1127 show max-completions
1128 Set the maximum number of candidates to be considered during
1129 completion. The default value is 200. This limit allows GDB
1130 to avoid generating large completion lists, the computation of
1131 which can cause the debugger to become temporarily unresponsive.
1133 set history remove-duplicates
1134 show history remove-duplicates
1135 Control the removal of duplicate history entries.
1137 maint set symbol-cache-size
1138 maint show symbol-cache-size
1139 Control the size of the symbol cache.
1141 set|show record btrace bts buffer-size
1142 Set and show the size of the ring buffer used for branch tracing in
1144 The obtained size may differ from the requested size. Use "info
1145 record" to see the obtained buffer size.
1147 set debug linux-namespaces
1148 show debug linux-namespaces
1149 Control display of debugging info regarding Linux namespaces.
1151 set|show record btrace pt buffer-size
1152 Set and show the size of the ring buffer used for branch tracing in
1153 Intel Processor Trace format.
1154 The obtained size may differ from the requested size. Use "info
1155 record" to see the obtained buffer size.
1157 maint set|show btrace pt skip-pad
1158 Set and show whether PAD packets are skipped when computing the
1161 * The command 'thread apply all' can now support new option '-ascending'
1162 to call its specified command for all threads in ascending order.
1164 * Python/Guile scripting
1166 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1167 special section named `.debug_gdb_scripts'.
1169 * New remote packets
1171 qXfer:btrace-conf:read
1172 Return the branch trace configuration for the current thread.
1174 Qbtrace-conf:bts:size
1175 Set the requested ring buffer size for branch tracing in BTS format.
1178 Enable Intel Procesor Trace-based branch tracing for the current
1179 process. The remote stub reports support for this packet to GDB's
1182 Qbtrace-conf:pt:size
1183 Set the requested ring buffer size for branch tracing in Intel Processor
1187 Indicates a memory breakpoint instruction was executed, irrespective
1188 of whether it was GDB that planted the breakpoint or the breakpoint
1189 is hardcoded in the program. This is required for correct non-stop
1193 Indicates the target stopped for a hardware breakpoint. This is
1194 required for correct non-stop mode operation.
1197 Return information about files on the remote system.
1199 qXfer:exec-file:read
1200 Return the full absolute name of the file that was executed to
1201 create a process running on the remote system.
1204 Select the filesystem on which vFile: operations with filename
1205 arguments will operate. This is required for GDB to be able to
1206 access files on remote targets where the remote stub does not
1207 share a common filesystem with the inferior(s).
1210 Indicates that a fork system call was executed.
1213 Indicates that a vfork system call was executed.
1215 vforkdone stop reason
1216 Indicates that a vfork child of the specified process has executed
1217 an exec or exit, allowing the vfork parent to resume execution.
1219 fork-events and vfork-events features in qSupported
1220 The qSupported packet allows GDB to request support for fork and
1221 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1222 and the qSupported response can contain the corresponding
1223 'stubfeatures'. Set and show commands can be used to display
1224 whether these features are enabled.
1226 * Extended-remote fork events
1228 ** GDB now has support for fork events on extended-remote Linux
1229 targets. For targets with Linux kernels 2.5.60 and later, this
1230 enables follow-fork-mode and detach-on-fork for both fork and
1231 vfork, as well as fork and vfork catchpoints.
1233 * The info record command now shows the recording format and the
1234 branch tracing configuration for the current thread when using
1235 the btrace record target.
1236 For the BTS format, it shows the ring buffer size.
1238 * GDB now has support for DTrace USDT (Userland Static Defined
1239 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1241 * GDB now supports access to vector registers on S/390 GNU/Linux
1244 * Removed command line options
1246 -xdb HP-UX XDB compatibility mode.
1248 * Removed targets and native configurations
1250 HP/PA running HP-UX hppa*-*-hpux*
1251 Itanium running HP-UX ia64-*-hpux*
1253 * New configure options
1256 This configure option allows the user to build GDB with support for
1257 Intel Processor Trace (default: auto). This requires libipt.
1259 --with-libipt-prefix=PATH
1260 Specify the path to the version of libipt that GDB should use.
1261 $PATH/include should contain the intel-pt.h header and
1262 $PATH/lib should contain the libipt.so library.
1264 *** Changes in GDB 7.9.1
1268 ** Xmethods can now specify a result type.
1270 *** Changes in GDB 7.9
1272 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1276 ** You can now access frame registers from Python scripts.
1277 ** New attribute 'producer' for gdb.Symtab objects.
1278 ** gdb.Objfile objects have a new attribute "progspace",
1279 which is the gdb.Progspace object of the containing program space.
1280 ** gdb.Objfile objects have a new attribute "owner".
1281 ** gdb.Objfile objects have a new attribute "build_id",
1282 which is the build ID generated when the file was built.
1283 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1284 ** A new event "gdb.clear_objfiles" has been added, triggered when
1285 selecting a new file to debug.
1286 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1287 ** New function gdb.lookup_objfile.
1289 New events which are triggered when GDB modifies the state of the
1292 ** gdb.events.inferior_call_pre: Function call is about to be made.
1293 ** gdb.events.inferior_call_post: Function call has just been made.
1294 ** gdb.events.memory_changed: A memory location has been altered.
1295 ** gdb.events.register_changed: A register has been altered.
1297 * New Python-based convenience functions:
1299 ** $_caller_is(name [, number_of_frames])
1300 ** $_caller_matches(regexp [, number_of_frames])
1301 ** $_any_caller_is(name [, number_of_frames])
1302 ** $_any_caller_matches(regexp [, number_of_frames])
1304 * GDB now supports the compilation and injection of source code into
1305 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1306 to compile the source code to object code, and if successful, inject
1307 and execute that code within the current context of the inferior.
1308 Currently the C language is supported. The commands used to
1309 interface with this new feature are:
1311 compile code [-raw|-r] [--] [source code]
1312 compile file [-raw|-r] filename
1316 demangle [-l language] [--] name
1317 Demangle "name" in the specified language, or the current language
1318 if elided. This command is renamed from the "maint demangle" command.
1319 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1320 as "maint demangler-warning".
1322 queue-signal signal-name-or-number
1323 Queue a signal to be delivered to the thread when it is resumed.
1325 add-auto-load-scripts-directory directory
1326 Add entries to the list of directories from which to load auto-loaded
1329 maint print user-registers
1330 List all currently available "user" registers.
1332 compile code [-r|-raw] [--] [source code]
1333 Compile, inject, and execute in the inferior the executable object
1334 code produced by compiling the provided source code.
1336 compile file [-r|-raw] filename
1337 Compile and inject into the inferior the executable object code
1338 produced by compiling the source code stored in the filename
1341 * On resume, GDB now always passes the signal the program had stopped
1342 for to the thread the signal was sent to, even if the user changed
1343 threads before resuming. Previously GDB would often (but not
1344 always) deliver the signal to the thread that happens to be current
1347 * Conversely, the "signal" command now consistently delivers the
1348 requested signal to the current thread. GDB now asks for
1349 confirmation if the program had stopped for a signal and the user
1350 switched threads meanwhile.
1352 * "breakpoint always-inserted" modes "off" and "auto" merged.
1354 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1355 won't remove breakpoints from the target until all threads stop,
1356 even in non-stop mode. The "auto" mode has been removed, and "off"
1357 is now the default mode.
1361 set debug symbol-lookup
1362 show debug symbol-lookup
1363 Control display of debugging info regarding symbol lookup.
1367 ** The -list-thread-groups command outputs an exit-code field for
1368 inferiors that have exited.
1372 MIPS SDE mips*-sde*-elf*
1376 Support for these obsolete configurations has been removed.
1378 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1379 SGI Irix-5.x mips-*-irix5*
1380 SGI Irix-6.x mips-*-irix6*
1381 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1382 VAX running Ultrix vax-*-ultrix*
1384 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1385 and "assf"), have been removed. Use the "sharedlibrary" command, or
1386 its alias "share", instead.
1388 *** Changes in GDB 7.8
1390 * New command line options
1393 This is an alias for the --data-directory option.
1395 * GDB supports printing and modifying of variable length automatic arrays
1396 as specified in ISO C99.
1398 * The ARM simulator now supports instruction level tracing
1399 with or without disassembly.
1403 GDB now has support for scripting using Guile. Whether this is
1404 available is determined at configure time.
1405 Guile version 2.0 or greater is required.
1406 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1408 * New commands (for set/show, see "New options" below)
1412 Invoke CODE by passing it to the Guile interpreter.
1416 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1418 info auto-load guile-scripts [regexp]
1419 Print the list of automatically loaded Guile scripts.
1421 * The source command is now capable of sourcing Guile scripts.
1422 This feature is dependent on the debugger being built with Guile support.
1426 set print symbol-loading (off|brief|full)
1427 show print symbol-loading
1428 Control whether to print informational messages when loading symbol
1429 information for a file. The default is "full", but when debugging
1430 programs with large numbers of shared libraries the amount of output
1431 becomes less useful.
1433 set guile print-stack (none|message|full)
1434 show guile print-stack
1435 Show a stack trace when an error is encountered in a Guile script.
1437 set auto-load guile-scripts (on|off)
1438 show auto-load guile-scripts
1439 Control auto-loading of Guile script files.
1441 maint ada set ignore-descriptive-types (on|off)
1442 maint ada show ignore-descriptive-types
1443 Control whether the debugger should ignore descriptive types in Ada
1444 programs. The default is not to ignore the descriptive types. See
1445 the user manual for more details on descriptive types and the intended
1446 usage of this option.
1448 set auto-connect-native-target
1450 Control whether GDB is allowed to automatically connect to the
1451 native target for the run, attach, etc. commands when not connected
1452 to any target yet. See also "target native" below.
1454 set record btrace replay-memory-access (read-only|read-write)
1455 show record btrace replay-memory-access
1456 Control what memory accesses are allowed during replay.
1458 maint set target-async (on|off)
1459 maint show target-async
1460 This controls whether GDB targets operate in synchronous or
1461 asynchronous mode. Normally the default is asynchronous, if it is
1462 available; but this can be changed to more easily debug problems
1463 occurring only in synchronous mode.
1465 set mi-async (on|off)
1467 Control whether MI asynchronous mode is preferred. This supersedes
1468 "set target-async" of previous GDB versions.
1470 * "set target-async" is deprecated as a CLI option and is now an alias
1471 for "set mi-async" (only puts MI into async mode).
1473 * Background execution commands (e.g., "c&", "s&", etc.) are now
1474 possible ``out of the box'' if the target supports them. Previously
1475 the user would need to explicitly enable the possibility with the
1476 "set target-async on" command.
1478 * New features in the GDB remote stub, GDBserver
1480 ** New option --debug-format=option1[,option2,...] allows one to add
1481 additional text to each output. At present only timestamps
1482 are supported: --debug-format=timestamps.
1483 Timestamps can also be turned on with the
1484 "monitor set debug-format timestamps" command from GDB.
1486 * The 'record instruction-history' command now starts counting instructions
1487 at one. This also affects the instruction ranges reported by the
1488 'record function-call-history' command when given the /i modifier.
1490 * The command 'record function-call-history' supports a new modifier '/c' to
1491 indent the function names based on their call stack depth.
1492 The fields for the '/i' and '/l' modifier have been reordered.
1493 The source line range is now prefixed with 'at'.
1494 The instruction range is now prefixed with 'inst'.
1495 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1496 "record instruction-history" and "list" commands.
1498 * The ranges given as arguments to the 'record function-call-history' and
1499 'record instruction-history' commands are now inclusive.
1501 * The btrace record target now supports the 'record goto' command.
1502 For locations inside the execution trace, the back trace is computed
1503 based on the information stored in the execution trace.
1505 * The btrace record target supports limited reverse execution and replay.
1506 The target does not record data and therefore does not allow reading
1507 memory or registers.
1509 * The "catch syscall" command now works on s390*-linux* targets.
1511 * The "compare-sections" command is no longer specific to target
1512 remote. It now works with all targets.
1514 * All native targets are now consistently called "native".
1515 Consequently, the "target child", "target GNU", "target djgpp",
1516 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1517 commands have been replaced with "target native". The QNX/NTO port
1518 leaves the "procfs" target in place and adds a "native" target for
1519 consistency with other ports. The impact on users should be minimal
1520 as these commands previously either throwed an error, or were
1521 no-ops. The target's name is visible in the output of the following
1522 commands: "help target", "info target", "info files", "maint print
1525 * The "target native" command now connects to the native target. This
1526 can be used to launch native programs even when "set
1527 auto-connect-native-target" is set to off.
1529 * GDB now supports access to Intel MPX registers on GNU/Linux.
1531 * Support for Intel AVX-512 registers on GNU/Linux.
1532 Support displaying and modifying Intel AVX-512 registers
1533 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1535 * New remote packets
1537 qXfer:btrace:read's annex
1538 The qXfer:btrace:read packet supports a new annex 'delta' to read
1539 branch trace incrementally.
1543 ** Valid Python operations on gdb.Value objects representing
1544 structs/classes invoke the corresponding overloaded operators if
1546 ** New `Xmethods' feature in the Python API. Xmethods are
1547 additional methods or replacements for existing methods of a C++
1548 class. This feature is useful for those cases where a method
1549 defined in C++ source code could be inlined or optimized out by
1550 the compiler, making it unavailable to GDB.
1553 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1555 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1556 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1557 its alias "share", instead.
1559 * The commands "set remotebaud" and "show remotebaud" are no longer
1560 supported. Use "set serial baud" and "show serial baud" (respectively)
1565 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1566 target-async". The latter is left as a deprecated alias of the
1567 former for backward compatibility. If the target supports it,
1568 CLI background execution commands are now always possible by
1569 default, independently of whether the frontend stated a
1570 preference for asynchronous execution with "-gdb-set mi-async".
1571 Previously "-gdb-set target-async off" affected both MI execution
1572 commands and CLI execution commands.
1574 *** Changes in GDB 7.7
1576 * Improved support for process record-replay and reverse debugging on
1577 arm*-linux* targets. Support for thumb32 and syscall instruction
1578 recording has been added.
1580 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1582 * GDB now supports Fission DWP file format version 2.
1583 http://gcc.gnu.org/wiki/DebugFission
1585 * New convenience function "$_isvoid", to check whether an expression
1586 is void. A void expression is an expression where the type of the
1587 result is "void". For example, some convenience variables may be
1588 "void" when evaluated (e.g., "$_exitcode" before the execution of
1589 the program being debugged; or an undefined convenience variable).
1590 Another example, when calling a function whose return type is
1593 * The "maintenance print objfiles" command now takes an optional regexp.
1595 * The "catch syscall" command now works on arm*-linux* targets.
1597 * GDB now consistently shows "<not saved>" when printing values of
1598 registers the debug info indicates have not been saved in the frame
1599 and there's nowhere to retrieve them from
1600 (callee-saved/call-clobbered registers):
1605 (gdb) info registers rax
1608 Before, the former would print "<optimized out>", and the latter
1609 "*value not available*".
1611 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1616 ** Frame filters and frame decorators have been added.
1617 ** Temporary breakpoints are now supported.
1618 ** Line tables representation has been added.
1619 ** New attribute 'parent_type' for gdb.Field objects.
1620 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1621 ** New attribute 'name' for gdb.Type objects.
1625 Nios II ELF nios2*-*-elf
1626 Nios II GNU/Linux nios2*-*-linux
1627 Texas Instruments MSP430 msp430*-*-elf
1629 * Removed native configurations
1631 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1632 been removed. ELF variants of these configurations are kept supported.
1634 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1635 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1636 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1637 i[34567]86-*-openbsd3.[0-3]
1638 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1639 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1640 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1644 Like "catch throw", but catches a re-thrown exception.
1645 maint check-psymtabs
1646 Renamed from old "maint check-symtabs".
1648 Perform consistency checks on symtabs.
1649 maint expand-symtabs
1650 Expand symtabs matching an optional regexp.
1653 Display the details of GDB configure-time options.
1655 maint set|show per-command
1656 maint set|show per-command space
1657 maint set|show per-command time
1658 maint set|show per-command symtab
1659 Enable display of per-command gdb resource usage.
1661 remove-symbol-file FILENAME
1662 remove-symbol-file -a ADDRESS
1663 Remove a symbol file added via add-symbol-file. The file to remove
1664 can be identified by its filename or by an address that lies within
1665 the boundaries of this symbol file in memory.
1668 info exceptions REGEXP
1669 Display the list of Ada exceptions defined in the program being
1670 debugged. If provided, only the exceptions whose names match REGEXP
1675 set debug symfile off|on
1677 Control display of debugging info regarding reading symbol files and
1678 symbol tables within those files
1680 set print raw frame-arguments
1681 show print raw frame-arguments
1682 Set/show whether to print frame arguments in raw mode,
1683 disregarding any defined pretty-printers.
1685 set remote trace-status-packet
1686 show remote trace-status-packet
1687 Set/show the use of remote protocol qTStatus packet.
1691 Control display of debugging messages related to Nios II targets.
1695 Control whether target-assisted range stepping is enabled.
1697 set startup-with-shell
1698 show startup-with-shell
1699 Specifies whether Unix child processes are started via a shell or
1704 Use the target memory cache for accesses to the code segment. This
1705 improves performance of remote debugging (particularly disassembly).
1707 * You can now use a literal value 'unlimited' for options that
1708 interpret 0 or -1 as meaning "unlimited". E.g., "set
1709 trace-buffer-size unlimited" is now an alias for "set
1710 trace-buffer-size -1" and "set height unlimited" is now an alias for
1713 * The "set debug symtab-create" debugging option of GDB has been changed to
1714 accept a verbosity level. 0 means "off", 1 provides basic debugging
1715 output, and values of 2 or greater provides more verbose output.
1717 * New command-line options
1719 Display the details of GDB configure-time options.
1721 * The command 'tsave' can now support new option '-ctf' to save trace
1722 buffer in Common Trace Format.
1724 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1727 * GDB now implements the the C++ 'typeid' operator.
1729 * The new convenience variable $_exception holds the exception being
1730 thrown or caught at an exception-related catchpoint.
1732 * The exception-related catchpoints, like "catch throw", now accept a
1733 regular expression which can be used to filter exceptions by type.
1735 * The new convenience variable $_exitsignal is automatically set to
1736 the terminating signal number when the program being debugged dies
1737 due to an uncaught signal.
1741 ** All MI commands now accept an optional "--language" option.
1742 Support for this feature can be verified by using the "-list-features"
1743 command, which should contain "language-option".
1745 ** The new command -info-gdb-mi-command allows the user to determine
1746 whether a GDB/MI command is supported or not.
1748 ** The "^error" result record returned when trying to execute an undefined
1749 GDB/MI command now provides a variable named "code" whose content is the
1750 "undefined-command" error code. Support for this feature can be verified
1751 by using the "-list-features" command, which should contain
1752 "undefined-command-error-code".
1754 ** The -trace-save MI command can optionally save trace buffer in Common
1757 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1759 ** The command -data-list-register-values now accepts an optional
1760 "--skip-unavailable" option. When used, only the available registers
1763 ** The new command -trace-frame-collected dumps collected variables,
1764 computed expressions, tvars, memory and registers in a traceframe.
1766 ** The commands -stack-list-locals, -stack-list-arguments and
1767 -stack-list-variables now accept an option "--skip-unavailable".
1768 When used, only the available locals or arguments are displayed.
1770 ** The -exec-run command now accepts an optional "--start" option.
1771 When used, the command follows the same semantics as the "start"
1772 command, stopping the program's execution at the start of its
1773 main subprogram. Support for this feature can be verified using
1774 the "-list-features" command, which should contain
1775 "exec-run-start-option".
1777 ** The new commands -catch-assert and -catch-exceptions insert
1778 catchpoints stopping the program when Ada exceptions are raised.
1780 ** The new command -info-ada-exceptions provides the equivalent of
1781 the new "info exceptions" command.
1783 * New system-wide configuration scripts
1784 A GDB installation now provides scripts suitable for use as system-wide
1785 configuration scripts for the following systems:
1789 * GDB now supports target-assigned range stepping with remote targets.
1790 This improves the performance of stepping source lines by reducing
1791 the number of control packets from/to GDB. See "New remote packets"
1794 * GDB now understands the element 'tvar' in the XML traceframe info.
1795 It has the id of the collected trace state variables.
1797 * On S/390 targets that provide the transactional-execution feature,
1798 the program interruption transaction diagnostic block (TDB) is now
1799 represented as a number of additional "registers" in GDB.
1801 * New remote packets
1805 The vCont packet supports a new 'r' action, that tells the remote
1806 stub to step through an address range itself, without GDB
1807 involvemement at each single-step.
1809 qXfer:libraries-svr4:read's annex
1810 The previously unused annex of the qXfer:libraries-svr4:read packet
1811 is now used to support passing an argument list. The remote stub
1812 reports support for this argument list to GDB's qSupported query.
1813 The defined arguments are "start" and "prev", used to reduce work
1814 necessary for library list updating, resulting in significant
1817 * New features in the GDB remote stub, GDBserver
1819 ** GDBserver now supports target-assisted range stepping. Currently
1820 enabled on x86/x86_64 GNU/Linux targets.
1822 ** GDBserver now adds element 'tvar' in the XML in the reply to
1823 'qXfer:traceframe-info:read'. It has the id of the collected
1824 trace state variables.
1826 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1829 * New 'z' formatter for printing and examining memory, this displays the
1830 value as hexadecimal zero padded on the left to the size of the type.
1832 * GDB can now use Windows x64 unwinding data.
1834 * The "set remotebaud" command has been replaced by "set serial baud".
1835 Similarly, "show remotebaud" has been replaced by "show serial baud".
1836 The "set remotebaud" and "show remotebaud" commands are still available
1837 to provide backward compatibility with older versions of GDB.
1839 *** Changes in GDB 7.6
1841 * Target record has been renamed to record-full.
1842 Record/replay is now enabled with the "record full" command.
1843 This also affects settings that are associated with full record/replay
1844 that have been moved from "set/show record" to "set/show record full":
1846 set|show record full insn-number-max
1847 set|show record full stop-at-limit
1848 set|show record full memory-query
1850 * A new record target "record-btrace" has been added. The new target
1851 uses hardware support to record the control-flow of a process. It
1852 does not support replaying the execution, but it implements the
1853 below new commands for investigating the recorded execution log.
1854 This new recording method can be enabled using:
1858 The "record-btrace" target is only available on Intel Atom processors
1859 and requires a Linux kernel 2.6.32 or later.
1861 * Two new commands have been added for record/replay to give information
1862 about the recorded execution without having to replay the execution.
1863 The commands are only supported by "record btrace".
1865 record instruction-history prints the execution history at
1866 instruction granularity
1868 record function-call-history prints the execution history at
1869 function granularity
1871 * New native configurations
1873 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1874 FreeBSD/powerpc powerpc*-*-freebsd
1875 x86_64/Cygwin x86_64-*-cygwin*
1876 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1880 ARM AArch64 aarch64*-*-elf
1881 ARM AArch64 GNU/Linux aarch64*-*-linux
1882 Lynx 178 PowerPC powerpc-*-lynx*178
1883 x86_64/Cygwin x86_64-*-cygwin*
1884 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1886 * If the configured location of system.gdbinit file (as given by the
1887 --with-system-gdbinit option at configure time) is in the
1888 data-directory (as specified by --with-gdb-datadir at configure
1889 time) or in one of its subdirectories, then GDB will look for the
1890 system-wide init file in the directory specified by the
1891 --data-directory command-line option.
1893 * New command line options:
1895 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1896 other initialization files, unlike -nx which disables all of them.
1898 * Removed command line options
1900 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1903 * The 'ptype' and 'whatis' commands now accept an argument to control
1906 * 'info proc' now works on some core files.
1910 ** Vectors can be created with gdb.Type.vector.
1912 ** Python's atexit.register now works in GDB.
1914 ** Types can be pretty-printed via a Python API.
1916 ** Python 3 is now supported (in addition to Python 2.4 or later)
1918 ** New class gdb.Architecture exposes GDB's internal representation
1919 of architecture in the Python API.
1921 ** New method Frame.architecture returns the gdb.Architecture object
1922 corresponding to the frame's architecture.
1924 * New Python-based convenience functions:
1926 ** $_memeq(buf1, buf2, length)
1927 ** $_streq(str1, str2)
1929 ** $_regex(str, regex)
1931 * The 'cd' command now defaults to using '~' (the home directory) if not
1934 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1935 default for GCC since November 2000.
1937 * The command 'forward-search' can now be abbreviated as 'fo'.
1939 * The command 'info tracepoints' can now display 'installed on target'
1940 or 'not installed on target' for each non-pending location of tracepoint.
1942 * New configure options
1944 --enable-libmcheck/--disable-libmcheck
1945 By default, development versions are built with -lmcheck on hosts
1946 that support it, in order to help track memory corruption issues.
1947 Release versions, on the other hand, are built without -lmcheck
1948 by default. The --enable-libmcheck/--disable-libmcheck configure
1949 options allow the user to override that default.
1950 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1951 This configure option allows the user to build GDB with
1952 libbabeltrace using which GDB can read Common Trace Format data.
1954 * New commands (for set/show, see "New options" below)
1957 Catch signals. This is similar to "handle", but allows commands and
1958 conditions to be attached.
1961 List the BFDs known to GDB.
1963 python-interactive [command]
1965 Start a Python interactive prompt, or evaluate the optional command
1966 and print the result of expressions.
1969 "py" is a new alias for "python".
1971 enable type-printer [name]...
1972 disable type-printer [name]...
1973 Enable or disable type printers.
1977 ** For the Renesas Super-H architecture, the "regs" command has been removed
1978 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1983 set print type methods (on|off)
1984 show print type methods
1985 Control whether method declarations are displayed by "ptype".
1986 The default is to show them.
1988 set print type typedefs (on|off)
1989 show print type typedefs
1990 Control whether typedef definitions are displayed by "ptype".
1991 The default is to show them.
1993 set filename-display basename|relative|absolute
1994 show filename-display
1995 Control the way in which filenames is displayed.
1996 The default is "relative", which preserves previous behavior.
1998 set trace-buffer-size
1999 show trace-buffer-size
2000 Request target to change the size of trace buffer.
2002 set remote trace-buffer-size-packet auto|on|off
2003 show remote trace-buffer-size-packet
2004 Control the use of the remote protocol `QTBuffer:size' packet.
2008 Control display of debugging messages related to ARM AArch64.
2011 set debug coff-pe-read
2012 show debug coff-pe-read
2013 Control display of debugging messages related to reading of COFF/PE
2018 Control display of debugging messages related to Mach-O symbols
2021 set debug notification
2022 show debug notification
2023 Control display of debugging info for async remote notification.
2027 ** Command parameter changes are now notified using new async record
2028 "=cmd-param-changed".
2029 ** Trace frame changes caused by command "tfind" are now notified using
2030 new async record "=traceframe-changed".
2031 ** The creation, deletion and modification of trace state variables
2032 are now notified using new async records "=tsv-created",
2033 "=tsv-deleted" and "=tsv-modified".
2034 ** The start and stop of process record are now notified using new
2035 async record "=record-started" and "=record-stopped".
2036 ** Memory changes are now notified using new async record
2038 ** The data-disassemble command response will include a "fullname" field
2039 containing the absolute file name when source has been requested.
2040 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2041 command, to allow pattern filling of memory areas.
2042 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2043 library load/unload events.
2044 ** The response to breakpoint commands and breakpoint async records
2045 includes an "installed" field containing a boolean state about each
2046 non-pending tracepoint location is whether installed on target or not.
2047 ** Output of the "-trace-status" command includes a "trace-file" field
2048 containing the name of the trace file being examined. This field is
2049 optional, and only present when examining a trace file.
2050 ** The "fullname" field is now always present along with the "file" field,
2051 even if the file cannot be found by GDB.
2053 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2054 You must have the LZMA library available when configuring GDB for this
2055 feature to be enabled. For more information, see:
2056 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2058 * New remote packets
2061 Set the size of trace buffer. The remote stub reports support for this
2062 packet to gdb's qSupported query.
2065 Enable Branch Trace Store (BTS)-based branch tracing for the current
2066 thread. The remote stub reports support for this packet to gdb's
2070 Disable branch tracing for the current thread. The remote stub reports
2071 support for this packet to gdb's qSupported query.
2074 Read the traced branches for the current thread. The remote stub
2075 reports support for this packet to gdb's qSupported query.
2077 *** Changes in GDB 7.5
2079 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2080 for more x32 ABI info.
2082 * GDB now supports access to MIPS DSP registers on Linux targets.
2084 * GDB now supports debugging microMIPS binaries.
2086 * The "info os" command on GNU/Linux can now display information on
2087 several new classes of objects managed by the operating system:
2088 "info os procgroups" lists process groups
2089 "info os files" lists file descriptors
2090 "info os sockets" lists internet-domain sockets
2091 "info os shm" lists shared-memory regions
2092 "info os semaphores" lists semaphores
2093 "info os msg" lists message queues
2094 "info os modules" lists loaded kernel modules
2096 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2097 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2098 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2099 options and inspect the probe arguments using the new $_probe_arg family
2100 of convenience variables. You can obtain more information about SystemTap
2101 in <http://sourceware.org/systemtap/>.
2103 * GDB now supports reversible debugging on ARM, it allows you to
2104 debug basic ARM and THUMB instructions, and provides
2105 record/replay support.
2107 * The option "symbol-reloading" has been deleted as it is no longer used.
2111 ** GDB commands implemented in Python can now be put in command class
2114 ** The "maint set python print-stack on|off" is now deleted.
2116 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2117 apply "flag enum"-style pretty-printing to any enum.
2119 ** gdb.lookup_symbol can now work when there is no current frame.
2121 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2122 the source at which the symbol was defined.
2124 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2125 method 'value'. The former indicates whether the symbol needs a
2126 frame in order to compute its value, and the latter computes the
2129 ** A new method 'referenced_value' on gdb.Value objects which can
2130 dereference pointer as well as C++ reference values.
2132 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2133 which return the global and static blocks (as gdb.Block objects),
2134 of the underlying symbol table, respectively.
2136 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2137 object associated with a PC value.
2139 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2140 of the address range occupied by code for the current source line.
2142 * Go language support.
2143 GDB now supports debugging programs written in the Go programming
2146 * GDBserver now supports stdio connections.
2147 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2149 * The binary "gdbtui" can no longer be built or installed.
2150 Use "gdb -tui" instead.
2152 * GDB will now print "flag" enums specially. A flag enum is one where
2153 all the enumerator values have no bits in common when pairwise
2154 "and"ed. When printing a value whose type is a flag enum, GDB will
2155 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2156 (gdb) print (enum E) 3
2159 * The filename part of a linespec will now match trailing components
2160 of a source file name. For example, "break gcc/expr.c:1000" will
2161 now set a breakpoint in build/gcc/expr.c, but not
2162 build/libcpp/expr.c.
2164 * The "info proc" and "generate-core-file" commands will now also
2165 work on remote targets connected to GDBserver on Linux.
2167 * The command "info catch" has been removed. It has been disabled
2168 since December 2007.
2170 * The "catch exception" and "catch assert" commands now accept
2171 a condition at the end of the command, much like the "break"
2172 command does. For instance:
2174 (gdb) catch exception Constraint_Error if Barrier = True
2176 Previously, it was possible to add a condition to such catchpoints,
2177 but it had to be done as a second step, after the catchpoint had been
2178 created, using the "condition" command.
2180 * The "info static-tracepoint-marker" command will now also work on
2181 native Linux targets with in-process agent.
2183 * GDB can now set breakpoints on inlined functions.
2185 * The .gdb_index section has been updated to include symbols for
2186 inlined functions. GDB will ignore older .gdb_index sections by
2187 default, which could cause symbol files to be loaded more slowly
2188 until their .gdb_index sections can be recreated. The new command
2189 "set use-deprecated-index-sections on" will cause GDB to use any older
2190 .gdb_index sections it finds. This will restore performance, but the
2191 ability to set breakpoints on inlined functions will be lost in symbol
2192 files with older .gdb_index sections.
2194 The .gdb_index section has also been updated to record more information
2195 about each symbol. This speeds up the "info variables", "info functions"
2196 and "info types" commands when used with programs having the .gdb_index
2197 section, as well as speeding up debugging with shared libraries using
2198 the .gdb_index section.
2200 * Ada support for GDB/MI Variable Objects has been added.
2202 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2207 ** New command -info-os is the MI equivalent of "info os".
2209 ** Output logs ("set logging" and related) now include MI output.
2213 ** "set use-deprecated-index-sections on|off"
2214 "show use-deprecated-index-sections on|off"
2215 Controls the use of deprecated .gdb_index sections.
2217 ** "catch load" and "catch unload" can be used to stop when a shared
2218 library is loaded or unloaded, respectively.
2220 ** "enable count" can be used to auto-disable a breakpoint after
2223 ** "info vtbl" can be used to show the virtual method tables for
2224 C++ and Java objects.
2226 ** "explore" and its sub commands "explore value" and "explore type"
2227 can be used to recursively explore values and types of
2228 expressions. These commands are available only if GDB is
2229 configured with '--with-python'.
2231 ** "info auto-load" shows status of all kinds of auto-loaded files,
2232 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2233 sequences of commands files, "info auto-load python-scripts"
2234 shows status of auto-loading Python script files,
2235 "info auto-load local-gdbinit" shows status of loading init file
2236 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2237 status of inferior specific thread debugging shared library loading.
2239 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2240 and "show auto-load-scripts" commands have been deprecated, use their
2241 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2242 and "show auto-load python-scripts" counterparts instead.
2244 ** "dprintf location,format,args..." creates a dynamic printf, which
2245 is basically a breakpoint that does a printf and immediately
2246 resumes your program's execution, so it is like a printf that you
2247 can insert dynamically at runtime instead of at compiletime.
2249 ** "set print symbol"
2251 Controls whether GDB attempts to display the symbol, if any,
2252 corresponding to addresses it prints. This defaults to "on", but
2253 you can set it to "off" to restore GDB's previous behavior.
2255 * Deprecated commands
2257 ** For the Renesas Super-H architecture, the "regs" command has been
2258 deprecated, and "info all-registers" should be used instead.
2262 Renesas RL78 rl78-*-elf
2263 HP OpenVMS ia64 ia64-hp-openvms*
2265 * GDBserver supports evaluation of breakpoint conditions. When
2266 support is advertised by GDBserver, GDB may be told to send the
2267 breakpoint conditions in bytecode form to GDBserver. GDBserver
2268 will only report the breakpoint trigger to GDB when its condition
2273 set mips compression
2274 show mips compression
2275 Select the compressed ISA encoding used in functions that have no symbol
2276 information available. The encoding can be set to either of:
2279 and is updated automatically from ELF file flags if available.
2281 set breakpoint condition-evaluation
2282 show breakpoint condition-evaluation
2283 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2284 GDBserver ("target"). Default option "auto" chooses the most efficient
2286 This option can improve debugger efficiency depending on the speed of the
2290 Disable auto-loading globally.
2293 Show auto-loading setting of all kinds of auto-loaded files.
2295 set auto-load gdb-scripts on|off
2296 show auto-load gdb-scripts
2297 Control auto-loading of GDB canned sequences of commands files.
2299 set auto-load python-scripts on|off
2300 show auto-load python-scripts
2301 Control auto-loading of Python script files.
2303 set auto-load local-gdbinit on|off
2304 show auto-load local-gdbinit
2305 Control loading of init file (.gdbinit) from current directory.
2307 set auto-load libthread-db on|off
2308 show auto-load libthread-db
2309 Control auto-loading of inferior specific thread debugging shared library.
2311 set auto-load scripts-directory <dir1>[:<dir2>...]
2312 show auto-load scripts-directory
2313 Set a list of directories from which to load auto-loaded scripts.
2314 Automatically loaded Python scripts and GDB scripts are located in one
2315 of the directories listed by this option.
2316 The delimiter (':' above) may differ according to the host platform.
2318 set auto-load safe-path <dir1>[:<dir2>...]
2319 show auto-load safe-path
2320 Set a list of directories from which it is safe to auto-load files.
2321 The delimiter (':' above) may differ according to the host platform.
2323 set debug auto-load on|off
2324 show debug auto-load
2325 Control display of debugging info for auto-loading the files above.
2327 set dprintf-style gdb|call|agent
2329 Control the way in which a dynamic printf is performed; "gdb"
2330 requests a GDB printf command, while "call" causes dprintf to call a
2331 function in the inferior. "agent" requests that the target agent
2332 (such as GDBserver) do the printing.
2334 set dprintf-function <expr>
2335 show dprintf-function
2336 set dprintf-channel <expr>
2337 show dprintf-channel
2338 Set the function and optional first argument to the call when using
2339 the "call" style of dynamic printf.
2341 set disconnected-dprintf on|off
2342 show disconnected-dprintf
2343 Control whether agent-style dynamic printfs continue to be in effect
2344 after GDB disconnects.
2346 * New configure options
2348 --with-auto-load-dir
2349 Configure default value for the 'set auto-load scripts-directory'
2350 setting above. It defaults to '$debugdir:$datadir/auto-load',
2351 $debugdir representing global debugging info directories (available
2352 via 'show debug-file-directory') and $datadir representing GDB's data
2353 directory (available via 'show data-directory').
2355 --with-auto-load-safe-path
2356 Configure default value for the 'set auto-load safe-path' setting
2357 above. It defaults to the --with-auto-load-dir setting.
2359 --without-auto-load-safe-path
2360 Set 'set auto-load safe-path' to '/', effectively disabling this
2363 * New remote packets
2365 z0/z1 conditional breakpoints extension
2367 The z0/z1 breakpoint insertion packets have been extended to carry
2368 a list of conditional expressions over to the remote stub depending on the
2369 condition evaluation mode. The use of this extension can be controlled
2370 via the "set remote conditional-breakpoints-packet" command.
2374 Specify the signals which the remote stub may pass to the debugged
2375 program without GDB involvement.
2377 * New command line options
2379 --init-command=FILE, -ix Like --command, -x but execute it
2380 before loading inferior.
2381 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2382 execute it before loading inferior.
2384 *** Changes in GDB 7.4
2386 * GDB now handles ambiguous linespecs more consistently; the existing
2387 FILE:LINE support has been expanded to other types of linespecs. A
2388 breakpoint will now be set on all matching locations in all
2389 inferiors, and locations will be added or removed according to
2392 * GDB now allows you to skip uninteresting functions and files when
2393 stepping with the "skip function" and "skip file" commands.
2395 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2396 and "show remote hardware-watchpoint-length-limit". These allows to
2397 set or show the maximum length limit (in bytes) of a remote
2398 target hardware watchpoint.
2400 This allows e.g. to use "unlimited" hardware watchpoints with the
2401 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2402 watchpoints are slower than real hardware watchpoints but are
2403 significantly faster than gdb software watchpoints.
2407 ** The register_pretty_printer function in module gdb.printing now takes
2408 an optional `replace' argument. If True, the new printer replaces any
2411 ** The "maint set python print-stack on|off" command has been
2412 deprecated and will be deleted in GDB 7.5.
2413 A new command: "set python print-stack none|full|message" has
2414 replaced it. Additionally, the default for "print-stack" is
2415 now "message", which just prints the error message without
2418 ** A prompt substitution hook (prompt_hook) is now available to the
2421 ** A new Python module, gdb.prompt has been added to the GDB Python
2422 modules library. This module provides functionality for
2423 escape sequences in prompts (used by set/show
2424 extended-prompt). These escape sequences are replaced by their
2425 corresponding value.
2427 ** Python commands and convenience-functions located in
2428 'data-directory'/python/gdb/command and
2429 'data-directory'/python/gdb/function are now automatically loaded
2432 ** Blocks now provide four new attributes. global_block and
2433 static_block will return the global and static blocks
2434 respectively. is_static and is_global are boolean attributes
2435 that indicate if the block is one of those two types.
2437 ** Symbols now provide the "type" attribute, the type of the symbol.
2439 ** The "gdb.breakpoint" function has been deprecated in favor of
2442 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2443 of a function. This class is based on the "finish" command
2444 available in the CLI.
2446 ** Type objects for struct and union types now allow access to
2447 the fields using standard Python dictionary (mapping) methods.
2448 For example, "some_type['myfield']" now works, as does
2449 "some_type.items()".
2451 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2454 ** A new function, "deep_items" has been added to the gdb.types
2455 module in the GDB Python modules library. This function returns
2456 an iterator over the fields of a struct or union type. Unlike
2457 the standard Python "iteritems" method, it will recursively traverse
2458 any anonymous fields.
2462 ** "*stopped" events can report several new "reason"s, such as
2465 ** Breakpoint changes are now notified using new async records, like
2466 "=breakpoint-modified".
2468 ** New command -ada-task-info.
2470 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2471 $sdir specifies the default system locations of shared libraries.
2472 $pdir specifies the directory where the libpthread used by the application
2475 GDB no longer looks in $sdir and $pdir after it has searched the directories
2476 mentioned in libthread-db-search-path. If you want to search those
2477 directories, they must be specified in libthread-db-search-path.
2478 The default value of libthread-db-search-path on GNU/Linux and Solaris
2479 systems is now "$sdir:$pdir".
2481 $pdir is not supported by gdbserver, it is currently ignored.
2482 $sdir is supported by gdbserver.
2484 * New configure option --with-iconv-bin.
2485 When using the internationalization support like the one in the GNU C
2486 library, GDB will invoke the "iconv" program to get a list of supported
2487 character sets. If this program lives in a non-standard location, one can
2488 use this option to specify where to find it.
2490 * When natively debugging programs on PowerPC BookE processors running
2491 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2492 watchpoints, which specify a mask in addition to an address to watch.
2493 The mask specifies that some bits of an address (the bits which are
2494 reset in the mask) should be ignored when matching the address accessed
2495 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2496 section in the user manual for more details.
2498 * The new option --once causes GDBserver to stop listening for connections once
2499 the first connection is made. The listening port used by GDBserver will
2500 become available after that.
2502 * New commands "info macros" and "alias" have been added.
2504 * New function parameters suffix @entry specifies value of function parameter
2505 at the time the function got called. Entry values are available only since
2511 "!" is now an alias of the "shell" command.
2512 Note that no space is needed between "!" and SHELL COMMAND.
2516 watch EXPRESSION mask MASK_VALUE
2517 The watch command now supports the mask argument which allows creation
2518 of masked watchpoints, if the current architecture supports this feature.
2520 info auto-load-scripts [REGEXP]
2521 This command was formerly named "maintenance print section-scripts".
2522 It is now generally useful and is no longer a maintenance-only command.
2524 info macro [-all] [--] MACRO
2525 The info macro command has new options `-all' and `--'. The first for
2526 printing all definitions of a macro. The second for explicitly specifying
2527 the end of arguments and the beginning of the macro name in case the macro
2528 name starts with a hyphen.
2530 collect[/s] EXPRESSIONS
2531 The tracepoint collect command now takes an optional modifier "/s"
2532 that directs it to dereference pointer-to-character types and
2533 collect the bytes of memory up to a zero byte. The behavior is
2534 similar to what you see when you use the regular print command on a
2535 string. An optional integer following the "/s" sets a bound on the
2536 number of bytes that will be collected.
2539 The trace start command now interprets any supplied arguments as a
2540 note to be recorded with the trace run, with an effect similar to
2541 setting the variable trace-notes.
2544 The trace stop command now interprets any arguments as a note to be
2545 mentioned along with the tstatus report that the trace was stopped
2546 with a command. The effect is similar to setting the variable
2549 * Tracepoints can now be enabled and disabled at any time after a trace
2550 experiment has been started using the standard "enable" and "disable"
2551 commands. It is now possible to start a trace experiment with no enabled
2552 tracepoints; GDB will display a warning, but will allow the experiment to
2553 begin, assuming that tracepoints will be enabled as needed while the trace
2556 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2557 locations with 4-byte instructions, when they were previously
2558 limited to locations with instructions of 5 bytes or longer.
2562 set debug dwarf2-read
2563 show debug dwarf2-read
2564 Turns on or off display of debugging messages related to reading
2565 DWARF debug info. The default is off.
2567 set debug symtab-create
2568 show debug symtab-create
2569 Turns on or off display of debugging messages related to symbol table
2570 creation. The default is off.
2573 show extended-prompt
2574 Set the GDB prompt, and allow escape sequences to be inserted to
2575 display miscellaneous information (see 'help set extended-prompt'
2576 for the list of sequences). This prompt (and any information
2577 accessed through the escape sequences) is updated every time the
2578 prompt is displayed.
2580 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2581 show print entry-values
2582 Set printing of frame argument values at function entry. In some cases
2583 GDB can determine the value of function argument which was passed by the
2584 function caller, even if the value was modified inside the called function.
2586 set debug entry-values
2587 show debug entry-values
2588 Control display of debugging info for determining frame argument values at
2589 function entry and virtual tail call frames.
2591 set basenames-may-differ
2592 show basenames-may-differ
2593 Set whether a source file may have multiple base names.
2594 (A "base name" is the name of a file with the directory part removed.
2595 Example: The base name of "/home/user/hello.c" is "hello.c".)
2596 If set, GDB will canonicalize file names (e.g., expand symlinks)
2597 before comparing them. Canonicalization is an expensive operation,
2598 but it allows the same file be known by more than one base name.
2599 If not set (the default), all source files are assumed to have just
2600 one base name, and gdb will do file name comparisons more efficiently.
2606 Set a user name and notes for the current and any future trace runs.
2607 This is useful for long-running and/or disconnected traces, to
2608 inform others (or yourself) as to who is running the trace, supply
2609 contact information, or otherwise explain what is going on.
2611 set trace-stop-notes
2612 show trace-stop-notes
2613 Set a note attached to the trace run, that is displayed when the
2614 trace has been stopped by a tstop command. This is useful for
2615 instance as an explanation, if you are stopping a trace run that was
2616 started by someone else.
2618 * New remote packets
2622 Dynamically enable a tracepoint in a started trace experiment.
2626 Dynamically disable a tracepoint in a started trace experiment.
2630 Set the user and notes of the trace run.
2634 Query the current status of a tracepoint.
2638 Query the minimum length of instruction at which a fast tracepoint may
2641 * Dcache size (number of lines) and line-size are now runtime-configurable
2642 via "set dcache line" and "set dcache line-size" commands.
2646 Texas Instruments TMS320C6x tic6x-*-*
2650 Renesas RL78 rl78-*-elf
2652 *** Changes in GDB 7.3.1
2654 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2656 *** Changes in GDB 7.3
2658 * GDB has a new command: "thread find [REGEXP]".
2659 It finds the thread id whose name, target id, or thread extra info
2660 matches the given regular expression.
2662 * The "catch syscall" command now works on mips*-linux* targets.
2664 * The -data-disassemble MI command now supports modes 2 and 3 for
2665 dumping the instruction opcodes.
2667 * New command line options
2669 -data-directory DIR Specify DIR as the "data-directory".
2670 This is mostly for testing purposes.
2672 * The "maint set python auto-load on|off" command has been renamed to
2673 "set auto-load-scripts on|off".
2675 * GDB has a new command: "set directories".
2676 It is like the "dir" command except that it replaces the
2677 source path list instead of augmenting it.
2679 * GDB now understands thread names.
2681 On GNU/Linux, "info threads" will display the thread name as set by
2682 prctl or pthread_setname_np.
2684 There is also a new command, "thread name", which can be used to
2685 assign a name internally for GDB to display.
2688 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2689 has been integrated into GDB.
2693 ** The function gdb.Write now accepts an optional keyword 'stream'.
2694 This keyword, when provided, will direct the output to either
2695 stdout, stderr, or GDB's logging output.
2697 ** Parameters can now be be sub-classed in Python, and in particular
2698 you may implement the get_set_doc and get_show_doc functions.
2699 This improves how Parameter set/show documentation is processed
2700 and allows for more dynamic content.
2702 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2703 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2704 have an is_valid method.
2706 ** Breakpoints can now be sub-classed in Python, and in particular
2707 you may implement a 'stop' function that is executed each time
2708 the inferior reaches that breakpoint.
2710 ** New function gdb.lookup_global_symbol looks up a global symbol.
2712 ** GDB values in Python are now callable if the value represents a
2713 function. For example, if 'some_value' represents a function that
2714 takes two integer parameters and returns a value, you can call
2715 that function like so:
2717 result = some_value (10,20)
2719 ** Module gdb.types has been added.
2720 It contains a collection of utilities for working with gdb.Types objects:
2721 get_basic_type, has_field, make_enum_dict.
2723 ** Module gdb.printing has been added.
2724 It contains utilities for writing and registering pretty-printers.
2725 New classes: PrettyPrinter, SubPrettyPrinter,
2726 RegexpCollectionPrettyPrinter.
2727 New function: register_pretty_printer.
2729 ** New commands "info pretty-printers", "enable pretty-printer" and
2730 "disable pretty-printer" have been added.
2732 ** gdb.parameter("directories") is now available.
2734 ** New function gdb.newest_frame returns the newest frame in the
2737 ** The gdb.InferiorThread class has a new "name" attribute. This
2738 holds the thread's name.
2740 ** Python Support for Inferior events.
2741 Python scripts can add observers to be notified of events
2742 occurring in the process being debugged.
2743 The following events are currently supported:
2744 - gdb.events.cont Continue event.
2745 - gdb.events.exited Inferior exited event.
2746 - gdb.events.stop Signal received, and Breakpoint hit events.
2750 ** GDB now puts template parameters in scope when debugging in an
2751 instantiation. For example, if you have:
2753 template<int X> int func (void) { return X; }
2755 then if you step into func<5>, "print X" will show "5". This
2756 feature requires proper debuginfo support from the compiler; it
2757 was added to GCC 4.5.
2759 ** The motion commands "next", "finish", "until", and "advance" now
2760 work better when exceptions are thrown. In particular, GDB will
2761 no longer lose control of the inferior; instead, the GDB will
2762 stop the inferior at the point at which the exception is caught.
2763 This functionality requires a change in the exception handling
2764 code that was introduced in GCC 4.5.
2766 * GDB now follows GCC's rules on accessing volatile objects when
2767 reading or writing target state during expression evaluation.
2768 One notable difference to prior behavior is that "print x = 0"
2769 no longer generates a read of x; the value of the assignment is
2770 now always taken directly from the value being assigned.
2772 * GDB now has some support for using labels in the program's source in
2773 linespecs. For instance, you can use "advance label" to continue
2774 execution to a label.
2776 * GDB now has support for reading and writing a new .gdb_index
2777 section. This section holds a fast index of DWARF debugging
2778 information and can be used to greatly speed up GDB startup and
2779 operation. See the documentation for `save gdb-index' for details.
2781 * The "watch" command now accepts an optional "-location" argument.
2782 When used, this causes GDB to watch the memory referred to by the
2783 expression. Such a watchpoint is never deleted due to it going out
2786 * GDB now supports thread debugging of core dumps on GNU/Linux.
2788 GDB now activates thread debugging using the libthread_db library
2789 when debugging GNU/Linux core dumps, similarly to when debugging
2790 live processes. As a result, when debugging a core dump file, GDB
2791 is now able to display pthread_t ids of threads. For example, "info
2792 threads" shows the same output as when debugging the process when it
2793 was live. In earlier releases, you'd see something like this:
2796 * 1 LWP 6780 main () at main.c:10
2798 While now you see this:
2801 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2803 It is also now possible to inspect TLS variables when debugging core
2806 When debugging a core dump generated on a machine other than the one
2807 used to run GDB, you may need to point GDB at the correct
2808 libthread_db library with the "set libthread-db-search-path"
2809 command. See the user manual for more details on this command.
2811 * When natively debugging programs on PowerPC BookE processors running
2812 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2813 which stop execution of the inferior whenever it executes an instruction
2814 at any address within the specified range. See the "PowerPC Embedded"
2815 section in the user manual for more details.
2817 * New features in the GDB remote stub, GDBserver
2819 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2820 and i686 LynxOS (version 5.x).
2822 ** GDBserver is now supported on Blackfin Linux.
2824 * New native configurations
2826 ia64 HP-UX ia64-*-hpux*
2830 Analog Devices, Inc. Blackfin Processor bfin-*
2832 * Ada task switching is now supported on sparc-elf targets when
2833 debugging a program using the Ravenscar Profile. For more information,
2834 see the "Tasking Support when using the Ravenscar Profile" section
2835 in the GDB user manual.
2837 * Guile support was removed.
2839 * New features in the GNU simulator
2841 ** The --map-info flag lists all known core mappings.
2843 ** CFI flashes may be simulated via the "cfi" device.
2845 *** Changes in GDB 7.2
2847 * Shared library support for remote targets by default
2849 When GDB is configured for a generic, non-OS specific target, like
2850 for example, --target=arm-eabi or one of the many *-*-elf targets,
2851 GDB now queries remote stubs for loaded shared libraries using the
2852 `qXfer:libraries:read' packet. Previously, shared library support
2853 was always disabled for such configurations.
2857 ** Argument Dependent Lookup (ADL)
2859 In C++ ADL lookup directs function search to the namespaces of its
2860 arguments even if the namespace has not been imported.
2870 Here the compiler will search for `foo' in the namespace of 'b'
2871 and find A::foo. GDB now supports this. This construct is commonly
2872 used in the Standard Template Library for operators.
2874 ** Improved User Defined Operator Support
2876 In addition to member operators, GDB now supports lookup of operators
2877 defined in a namespace and imported with a `using' directive, operators
2878 defined in the global scope, operators imported implicitly from an
2879 anonymous namespace, and the ADL operators mentioned in the previous
2881 GDB now also supports proper overload resolution for all the previously
2882 mentioned flavors of operators.
2884 ** static const class members
2886 Printing of static const class members that are initialized in the
2887 class definition has been fixed.
2889 * Windows Thread Information Block access.
2891 On Windows targets, GDB now supports displaying the Windows Thread
2892 Information Block (TIB) structure. This structure is visible either
2893 by using the new command `info w32 thread-information-block' or, by
2894 dereferencing the new convenience variable named `$_tlb', a
2895 thread-specific pointer to the TIB. This feature is also supported
2896 when remote debugging using GDBserver.
2898 * Static tracepoints
2900 Static tracepoints are calls in the user program into a tracing
2901 library. One such library is a port of the LTTng kernel tracer to
2902 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2903 When debugging with GDBserver, GDB now supports combining the GDB
2904 tracepoint machinery with such libraries. For example: the user can
2905 use GDB to probe a static tracepoint marker (a call from the user
2906 program into the tracing library) with the new "strace" command (see
2907 "New commands" below). This creates a "static tracepoint" in the
2908 breakpoint list, that can be manipulated with the same feature set
2909 as fast and regular tracepoints. E.g., collect registers, local and
2910 global variables, collect trace state variables, and define
2911 tracepoint conditions. In addition, the user can collect extra
2912 static tracepoint marker specific data, by collecting the new
2913 $_sdata internal variable. When analyzing the trace buffer, you can
2914 inspect $_sdata like any other variable available to GDB. For more
2915 information, see the "Tracepoints" chapter in GDB user manual. New
2916 remote packets have been defined to support static tracepoints, see
2917 the "New remote packets" section below.
2919 * Better reconstruction of tracepoints after disconnected tracing
2921 GDB will attempt to download the original source form of tracepoint
2922 definitions when starting a trace run, and then will upload these
2923 upon reconnection to the target, resulting in a more accurate
2924 reconstruction of the tracepoints that are in use on the target.
2928 You can now exercise direct control over the ways that GDB can
2929 affect your program. For instance, you can disallow the setting of
2930 breakpoints, so that the program can run continuously (assuming
2931 non-stop mode). In addition, the "observer" variable is available
2932 to switch all of the different controls; in observer mode, GDB
2933 cannot affect the target's behavior at all, which is useful for
2934 tasks like diagnosing live systems in the field.
2936 * The new convenience variable $_thread holds the number of the
2939 * New remote packets
2943 Return the address of the Windows Thread Information Block of a given thread.
2947 In response to several of the tracepoint packets, the target may now
2948 also respond with a number of intermediate `qRelocInsn' request
2949 packets before the final result packet, to have GDB handle
2950 relocating an instruction to execute at a different address. This
2951 is particularly useful for stubs that support fast tracepoints. GDB
2952 reports support for this feature in the qSupported packet.
2956 List static tracepoint markers in the target program.
2960 List static tracepoint markers at a given address in the target
2963 qXfer:statictrace:read
2965 Read the static trace data collected (by a `collect $_sdata'
2966 tracepoint action). The remote stub reports support for this packet
2967 to gdb's qSupported query.
2971 Send the current settings of GDB's permission flags.
2975 Send part of the source (textual) form of a tracepoint definition,
2976 which includes location, conditional, and action list.
2978 * The source command now accepts a -s option to force searching for the
2979 script in the source search path even if the script name specifies
2982 * New features in the GDB remote stub, GDBserver
2984 - GDBserver now support tracepoints (including fast tracepoints, and
2985 static tracepoints). The feature is currently supported by the
2986 i386-linux and amd64-linux builds. See the "Tracepoints support
2987 in gdbserver" section in the manual for more information.
2989 GDBserver JIT compiles the tracepoint's conditional agent
2990 expression bytecode into native code whenever possible for low
2991 overhead dynamic tracepoints conditionals. For such tracepoints,
2992 an expression that examines program state is evaluated when the
2993 tracepoint is reached, in order to determine whether to capture
2994 trace data. If the condition is simple and false, processing the
2995 tracepoint finishes very quickly and no data is gathered.
2997 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2998 for static tracepoints support.
3000 - GDBserver now supports x86_64 Windows 64-bit debugging.
3002 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3003 it understands register description.
3005 * The --batch flag now disables pagination and queries.
3007 * X86 general purpose registers
3009 GDB now supports reading/writing byte, word and double-word x86
3010 general purpose registers directly. This means you can use, say,
3011 $ah or $ax to refer, respectively, to the byte register AH and
3012 16-bit word register AX that are actually portions of the 32-bit
3013 register EAX or 64-bit register RAX.
3015 * The `commands' command now accepts a range of breakpoints to modify.
3016 A plain `commands' following a command that creates multiple
3017 breakpoints affects all the breakpoints set by that command. This
3018 applies to breakpoints set by `rbreak', and also applies when a
3019 single `break' command creates multiple breakpoints (e.g.,
3020 breakpoints on overloaded c++ functions).
3022 * The `rbreak' command now accepts a filename specification as part of
3023 its argument, limiting the functions selected by the regex to those
3024 in the specified file.
3026 * Support for remote debugging Windows and SymbianOS shared libraries
3027 from Unix hosts has been improved. Non Windows GDB builds now can
3028 understand target reported file names that follow MS-DOS based file
3029 system semantics, such as file names that include drive letters and
3030 use the backslash character as directory separator. This makes it
3031 possible to transparently use the "set sysroot" and "set
3032 solib-search-path" on Unix hosts to point as host copies of the
3033 target's shared libraries. See the new command "set
3034 target-file-system-kind" described below, and the "Commands to
3035 specify files" section in the user manual for more information.
3039 eval template, expressions...
3040 Convert the values of one or more expressions under the control
3041 of the string template to a command line, and call it.
3043 set target-file-system-kind unix|dos-based|auto
3044 show target-file-system-kind
3045 Set or show the assumed file system kind for target reported file
3048 save breakpoints <filename>
3049 Save all current breakpoint definitions to a file suitable for use
3050 in a later debugging session. To read the saved breakpoint
3051 definitions, use the `source' command.
3053 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3056 info static-tracepoint-markers
3057 Display information about static tracepoint markers in the target.
3059 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3060 Define a static tracepoint by probing a marker at the given
3061 function, line, address, or marker ID.
3065 Enable and disable observer mode.
3067 set may-write-registers on|off
3068 set may-write-memory on|off
3069 set may-insert-breakpoints on|off
3070 set may-insert-tracepoints on|off
3071 set may-insert-fast-tracepoints on|off
3072 set may-interrupt on|off
3073 Set individual permissions for GDB effects on the target. Note that
3074 some of these settings can have undesirable or surprising
3075 consequences, particularly when changed in the middle of a session.
3076 For instance, disabling the writing of memory can prevent
3077 breakpoints from being inserted, cause single-stepping to fail, or
3078 even crash your program, if you disable after breakpoints have been
3079 inserted. However, GDB should not crash.
3081 set record memory-query on|off
3082 show record memory-query
3083 Control whether to stop the inferior if memory changes caused
3084 by an instruction cannot be recorded.
3089 The disassemble command now supports "start,+length" form of two arguments.
3093 ** GDB now provides a new directory location, called the python directory,
3094 where Python scripts written for GDB can be installed. The location
3095 of that directory is <data-directory>/python, where <data-directory>
3096 is the GDB data directory. For more details, see section `Scripting
3097 GDB using Python' in the manual.
3099 ** The GDB Python API now has access to breakpoints, symbols, symbol
3100 tables, program spaces, inferiors, threads and frame's code blocks.
3101 Additionally, GDB Parameters can now be created from the API, and
3102 manipulated via set/show in the CLI.
3104 ** New functions gdb.target_charset, gdb.target_wide_charset,
3105 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3107 ** New exception gdb.GdbError.
3109 ** Pretty-printers are now also looked up in the current program space.
3111 ** Pretty-printers can now be individually enabled and disabled.
3113 ** GDB now looks for names of Python scripts to auto-load in a
3114 special section named `.debug_gdb_scripts', in addition to looking
3115 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3117 * Tracepoint actions were unified with breakpoint commands. In particular,
3118 there are no longer differences in "info break" output for breakpoints and
3119 tracepoints and the "commands" command can be used for both tracepoints and
3120 regular breakpoints.
3124 ARM Symbian arm*-*-symbianelf*
3126 * D language support.
3127 GDB now supports debugging programs written in the D programming
3130 * GDB now supports the extended ptrace interface for PowerPC which is
3131 available since Linux kernel version 2.6.34. This automatically enables
3132 any hardware breakpoints and additional hardware watchpoints available in
3133 the processor. The old ptrace interface exposes just one hardware
3134 watchpoint and no hardware breakpoints.
3136 * GDB is now able to use the Data Value Compare (DVC) register available on
3137 embedded PowerPC processors to implement in hardware simple watchpoint
3138 conditions of the form:
3140 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3142 This works in native GDB running on Linux kernels with the extended ptrace
3143 interface mentioned above.
3145 *** Changes in GDB 7.1
3149 ** Namespace Support
3151 GDB now supports importing of namespaces in C++. This enables the
3152 user to inspect variables from imported namespaces. Support for
3153 namepace aliasing has also been added. So, if a namespace is
3154 aliased in the current scope (e.g. namepace C=A; ) the user can
3155 print variables using the alias (e.g. (gdb) print C::x).
3159 All known bugs relating to the printing of virtual base class were
3160 fixed. It is now possible to call overloaded static methods using a
3165 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3166 and reinterpret_cast<> are now handled by the C++ expression parser.
3170 Xilinx MicroBlaze microblaze-*-*
3175 Xilinx MicroBlaze microblaze
3178 * Multi-program debugging.
3180 GDB now has support for multi-program (a.k.a. multi-executable or
3181 multi-exec) debugging. This allows for debugging multiple inferiors
3182 simultaneously each running a different program under the same GDB
3183 session. See "Debugging Multiple Inferiors and Programs" in the
3184 manual for more information. This implied some user visible changes
3185 in the multi-inferior support. For example, "info inferiors" now
3186 lists inferiors that are not running yet or that have exited
3187 already. See also "New commands" and "New options" below.
3189 * New tracing features
3191 GDB's tracepoint facility now includes several new features:
3193 ** Trace state variables
3195 GDB tracepoints now include support for trace state variables, which
3196 are variables managed by the target agent during a tracing
3197 experiment. They are useful for tracepoints that trigger each
3198 other, so for instance one tracepoint can count hits in a variable,
3199 and then a second tracepoint has a condition that is true when the
3200 count reaches a particular value. Trace state variables share the
3201 $-syntax of GDB convenience variables, and can appear in both
3202 tracepoint actions and condition expressions. Use the "tvariable"
3203 command to create, and "info tvariables" to view; see "Trace State
3204 Variables" in the manual for more detail.
3208 GDB now includes an option for defining fast tracepoints, which
3209 targets may implement more efficiently, such as by installing a jump
3210 into the target agent rather than a trap instruction. The resulting
3211 speedup can be by two orders of magnitude or more, although the
3212 tradeoff is that some program locations on some target architectures
3213 might not allow fast tracepoint installation, for instance if the
3214 instruction to be replaced is shorter than the jump. To request a
3215 fast tracepoint, use the "ftrace" command, with syntax identical to
3216 the regular trace command.
3218 ** Disconnected tracing
3220 It is now possible to detach GDB from the target while it is running
3221 a trace experiment, then reconnect later to see how the experiment
3222 is going. In addition, a new variable disconnected-tracing lets you
3223 tell the target agent whether to continue running a trace if the
3224 connection is lost unexpectedly.
3228 GDB now has the ability to save the trace buffer into a file, and
3229 then use that file as a target, similarly to you can do with
3230 corefiles. You can select trace frames, print data that was
3231 collected in them, and use tstatus to display the state of the
3232 tracing run at the moment that it was saved. To create a trace
3233 file, use "tsave <filename>", and to use it, do "target tfile
3236 ** Circular trace buffer
3238 You can ask the target agent to handle the trace buffer as a
3239 circular buffer, discarding the oldest trace frames to make room for
3240 newer ones, by setting circular-trace-buffer to on. This feature may
3241 not be available for all target agents.
3246 The disassemble command, when invoked with two arguments, now requires
3247 the arguments to be comma-separated.
3250 The info variables command now displays variable definitions. Files
3251 which only declare a variable are not shown.
3254 The source command is now capable of sourcing Python scripts.
3255 This feature is dependent on the debugger being build with Python
3258 Related to this enhancement is also the introduction of a new command
3259 "set script-extension" (see below).
3261 * New commands (for set/show, see "New options" below)
3263 record save [<FILENAME>]
3264 Save a file (in core file format) containing the process record
3265 execution log for replay debugging at a later time.
3267 record restore <FILENAME>
3268 Restore the process record execution log that was saved at an
3269 earlier time, for replay debugging.
3271 add-inferior [-copies <N>] [-exec <FILENAME>]
3274 clone-inferior [-copies <N>] [ID]
3275 Make a new inferior ready to execute the same program another
3276 inferior has loaded.
3281 maint info program-spaces
3282 List the program spaces loaded into GDB.
3284 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3285 show remote interrupt-sequence
3286 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3287 as the sequence to the remote target in order to interrupt the execution.
3288 Ctrl-C is a default. Some system prefers BREAK which is high level of
3289 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3290 Magic SysRq g. It is BREAK signal and character 'g'.
3292 set remote interrupt-on-connect [on | off]
3293 show remote interrupt-on-connect
3294 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3295 remote target when gdb connects to it. This is needed when you debug
3298 set remotebreak [on | off]
3300 Deprecated. Use "set/show remote interrupt-sequence" instead.
3302 tvariable $NAME [ = EXP ]
3303 Create or modify a trace state variable.
3306 List trace state variables and their values.
3308 delete tvariable $NAME ...
3309 Delete one or more trace state variables.
3312 Evaluate the given expressions without collecting anything into the
3313 trace buffer. (Valid in tracepoint actions only.)
3315 ftrace FN / FILE:LINE / *ADDR
3316 Define a fast tracepoint at the given function, line, or address.
3318 * New expression syntax
3320 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3321 GDB now parses 0b101010 identically with 42.
3325 set follow-exec-mode new|same
3326 show follow-exec-mode
3327 Control whether GDB reuses the same inferior across an exec call or
3328 creates a new one. This is useful to be able to restart the old
3329 executable after the inferior having done an exec call.
3331 set default-collect EXPR, ...
3332 show default-collect
3333 Define a list of expressions to be collected at each tracepoint.
3334 This is a useful way to ensure essential items are not overlooked,
3335 such as registers or a critical global variable.
3337 set disconnected-tracing
3338 show disconnected-tracing
3339 If set to 1, the target is instructed to continue tracing if it
3340 loses its connection to GDB. If 0, the target is to stop tracing
3343 set circular-trace-buffer
3344 show circular-trace-buffer
3345 If set to on, the target is instructed to use a circular trace buffer
3346 and discard the oldest trace frames instead of stopping the trace due
3347 to a full trace buffer. If set to off, the trace stops when the buffer
3348 fills up. Some targets may not support this.
3350 set script-extension off|soft|strict
3351 show script-extension
3352 If set to "off", the debugger does not perform any script language
3353 recognition, and all sourced files are assumed to be GDB scripts.
3354 If set to "soft" (the default), files are sourced according to
3355 filename extension, falling back to GDB scripts if the first
3357 If set to "strict", files are sourced according to filename extension.
3359 set ada trust-PAD-over-XVS on|off
3360 show ada trust-PAD-over-XVS
3361 If off, activate a workaround against a bug in the debugging information
3362 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3363 the GCC sources for more information about the GNAT encoding and
3364 PAD types in particular). It is always safe to set this option to
3365 off, but this introduces a slight performance penalty. The default
3368 * Python API Improvements
3370 ** GDB provides the new class gdb.LazyString. This is useful in
3371 some pretty-printing cases. The new method gdb.Value.lazy_string
3372 provides a simple way to create objects of this type.
3374 ** The fields returned by gdb.Type.fields now have an
3375 `is_base_class' attribute.
3377 ** The new method gdb.Type.range returns the range of an array type.
3379 ** The new method gdb.parse_and_eval can be used to parse and
3380 evaluate an expression.
3382 * New remote packets
3385 Define a trace state variable.
3388 Get the current value of a trace state variable.
3391 Set desired tracing behavior upon disconnection.
3394 Set the trace buffer to be linear or circular.
3397 Get data about the tracepoints currently in use.
3401 Process record now works correctly with hardware watchpoints.
3403 Multiple bug fixes have been made to the mips-irix port, making it
3404 much more reliable. In particular:
3405 - Debugging threaded applications is now possible again. Previously,
3406 GDB would hang while starting the program, or while waiting for
3407 the program to stop at a breakpoint.
3408 - Attaching to a running process no longer hangs.
3409 - An error occurring while loading a core file has been fixed.
3410 - Changing the value of the PC register now works again. This fixes
3411 problems observed when using the "jump" command, or when calling
3412 a function from GDB, or even when assigning a new value to $pc.
3413 - With the "finish" and "return" commands, the return value for functions
3414 returning a small array is now correctly printed.
3415 - It is now possible to break on shared library code which gets executed
3416 during a shared library init phase (code executed while executing
3417 their .init section). Previously, the breakpoint would have no effect.
3418 - GDB is now able to backtrace through the signal handler for
3419 non-threaded programs.
3421 PIE (Position Independent Executable) programs debugging is now supported.
3422 This includes debugging execution of PIC (Position Independent Code) shared
3423 libraries although for that, it should be possible to run such libraries as an
3426 *** Changes in GDB 7.0
3428 * GDB now has an interface for JIT compilation. Applications that
3429 dynamically generate code can create symbol files in memory and register
3430 them with GDB. For users, the feature should work transparently, and
3431 for JIT developers, the interface is documented in the GDB manual in the
3432 "JIT Compilation Interface" chapter.
3434 * Tracepoints may now be conditional. The syntax is as for
3435 breakpoints; either an "if" clause appended to the "trace" command,
3436 or the "condition" command is available. GDB sends the condition to
3437 the target for evaluation using the same bytecode format as is used
3438 for tracepoint actions.
3440 * The disassemble command now supports: an optional /r modifier, print the
3441 raw instructions in hex as well as in symbolic form, and an optional /m
3442 modifier to print mixed source+assembly.
3444 * Process record and replay
3446 In a architecture environment that supports ``process record and
3447 replay'', ``process record and replay'' target can record a log of
3448 the process execution, and replay it with both forward and reverse
3451 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3452 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3453 set execution-direction {forward|reverse}, for targets that support
3456 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3457 feature is available with a native GDB running on kernel version
3460 * GDB now has support for multi-byte and wide character sets on the
3461 target. Strings whose character type is wchar_t, char16_t, or
3462 char32_t are now correctly printed. GDB supports wide- and unicode-
3463 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3464 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3465 `printf'. This feature requires iconv to work properly; if your
3466 system does not have a working iconv, GDB can use GNU libiconv. See
3467 the installation instructions for more information.
3469 * GDB now supports automatic retrieval of shared library files from
3470 remote targets. To use this feature, specify a system root that begins
3471 with the `remote:' prefix, either via the `set sysroot' command or via
3472 the `--with-sysroot' configure-time option.
3474 * "info sharedlibrary" now takes an optional regex of libraries to show,
3475 and it now reports if a shared library has no debugging information.
3477 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3478 now complete on file names.
3480 * When completing in expressions, gdb will attempt to limit
3481 completions to allowable structure or union fields, where appropriate.
3482 For instance, consider:
3484 # struct example { int f1; double f2; };
3485 # struct example variable;
3488 If the user types TAB at the end of this command line, the available
3489 completions will be "f1" and "f2".
3491 * Inlined functions are now supported. They show up in backtraces, and
3492 the "step", "next", and "finish" commands handle them automatically.
3494 * GDB now supports the token-splicing (##) and stringification (#)
3495 operators when expanding macros. It also supports variable-arity
3498 * GDB now supports inspecting extra signal information, exported by
3499 the new $_siginfo convenience variable. The feature is currently
3500 implemented on linux ARM, i386 and amd64.
3502 * GDB can now display the VFP floating point registers and NEON vector
3503 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3504 can provide these registers (requires Linux 2.6.30 or later). Remote
3505 and simulator targets may also provide them.
3507 * New remote packets
3510 Search memory for a sequence of bytes.
3513 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3514 operation over reliable transport links. Use of this packet is
3515 controlled by the `set remote noack-packet' command.
3518 Kill the process with the specified process ID. Use this in preference
3519 to `k' when multiprocess protocol extensions are supported.
3522 Obtains additional operating system information
3526 Read or write additional signal information.
3528 * Removed remote protocol undocumented extension
3530 An undocumented extension to the remote protocol's `S' stop reply
3531 packet that permited the stub to pass a process id was removed.
3532 Remote servers should use the `T' stop reply packet instead.
3534 * GDB now supports multiple function calling conventions according to the
3535 DWARF-2 DW_AT_calling_convention function attribute.
3537 * The SH target utilizes the aforementioned change to distinguish between gcc
3538 and Renesas calling convention. It also adds the new CLI commands
3539 `set/show sh calling-convention'.
3541 * GDB can now read compressed debug sections, as produced by GNU gold
3542 with the --compress-debug-sections=zlib flag.
3544 * 64-bit core files are now supported on AIX.
3546 * Thread switching is now supported on Tru64.
3548 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3549 which will be allocated using malloc later in program execution.
3551 * The qXfer:libraries:read remote procotol packet now allows passing a
3552 list of section offsets.
3554 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3555 conditions handling signals delivered during attach or thread creation
3556 have also been fixed.
3558 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3559 From the user's standpoint, all unqualified instances of True and False
3560 are treated as the standard definitions, regardless of context.
3562 * GDB now parses C++ symbol and type names more flexibly. For
3565 template<typename T> class C { };
3568 GDB will now correctly handle all of:
3570 ptype C<char const *>
3571 ptype C<char const*>
3572 ptype C<const char *>
3573 ptype C<const char*>
3575 * New features in the GDB remote stub, gdbserver
3577 - The "--wrapper" command-line argument tells gdbserver to use a
3578 wrapper program to launch programs for debugging.
3580 - On PowerPC and S/390 targets, it is now possible to use a single
3581 gdbserver executable to debug both 32-bit and 64-bit programs.
3582 (This requires gdbserver itself to be built as a 64-bit executable.)
3584 - gdbserver uses the new noack protocol mode for TCP connections to
3585 reduce communications latency, if also supported and enabled in GDB.
3587 - Support for the sparc64-linux-gnu target is now included in
3590 - The amd64-linux build of gdbserver now supports debugging both
3591 32-bit and 64-bit programs.
3593 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3594 now support hardware watchpoints, and will use them automatically
3599 GDB now has support for scripting using Python. Whether this is
3600 available is determined at configure time.
3602 New GDB commands can now be written in Python.
3604 * Ada tasking support
3606 Ada tasks can now be inspected in GDB. The following commands have
3610 Print the list of Ada tasks.
3612 Print detailed information about task number N.
3614 Print the task number of the current task.
3616 Switch the context of debugging to task number N.
3618 * Support for user-defined prefixed commands. The "define" command can
3619 add new commands to existing prefixes, e.g. "target".
3621 * Multi-inferior, multi-process debugging.
3623 GDB now has generalized support for multi-inferior debugging. See
3624 "Debugging Multiple Inferiors" in the manual for more information.
3625 Although availability still depends on target support, the command
3626 set is more uniform now. The GNU/Linux specific multi-forks support
3627 has been migrated to this new framework. This implied some user
3628 visible changes; see "New commands" and also "Removed commands"
3631 * Target descriptions can now describe the target OS ABI. See the
3632 "Target Description Format" section in the user manual for more
3635 * Target descriptions can now describe "compatible" architectures
3636 to indicate that the target can execute applications for a different
3637 architecture in addition to those for the main target architecture.
3638 See the "Target Description Format" section in the user manual for
3641 * Multi-architecture debugging.
3643 GDB now includes general supports for debugging applications on
3644 hybrid systems that use more than one single processor architecture
3645 at the same time. Each such hybrid architecture still requires
3646 specific support to be added. The only hybrid architecture supported
3647 in this version of GDB is the Cell Broadband Engine.
3649 * GDB now supports integrated debugging of Cell/B.E. applications that
3650 use both the PPU and SPU architectures. To enable support for hybrid
3651 Cell/B.E. debugging, you need to configure GDB to support both the
3652 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3653 --enable-targets configure option.
3655 * Non-stop mode debugging.
3657 For some targets, GDB now supports an optional mode of operation in
3658 which you can examine stopped threads while other threads continue
3659 to execute freely. This is referred to as non-stop mode, with the
3660 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3661 section in the user manual for more information.
3663 To be able to support remote non-stop debugging, a remote stub needs
3664 to implement the non-stop mode remote protocol extensions, as
3665 described in the "Remote Non-Stop" section of the user manual. The
3666 GDB remote stub, gdbserver, has been adjusted to support these
3667 extensions on linux targets.
3669 * New commands (for set/show, see "New options" below)
3671 catch syscall [NAME(S) | NUMBER(S)]
3672 Catch system calls. Arguments, which should be names of system
3673 calls or their numbers, mean catch only those syscalls. Without
3674 arguments, every syscall will be caught. When the inferior issues
3675 any of the specified syscalls, GDB will stop and announce the system
3676 call, both when it is called and when its call returns. This
3677 feature is currently available with a native GDB running on the
3678 Linux Kernel, under the following architectures: x86, x86_64,
3679 PowerPC and PowerPC64.
3681 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3683 Search memory for a sequence of bytes.
3685 maint set python print-stack
3686 maint show python print-stack
3687 Show a stack trace when an error is encountered in a Python script.
3690 Invoke CODE by passing it to the Python interpreter.
3695 These allow macros to be defined, undefined, and listed
3699 Show operating system information about processes.
3702 List the inferiors currently under GDB's control.
3705 Switch focus to inferior number NUM.
3708 Detach from inferior number NUM.
3711 Kill inferior number NUM.
3715 set spu stop-on-load
3716 show spu stop-on-load
3717 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3719 set spu auto-flush-cache
3720 show spu auto-flush-cache
3721 Control whether to automatically flush the software-managed cache
3722 during Cell/B.E. debugging.
3724 set sh calling-convention
3725 show sh calling-convention
3726 Control the calling convention used when calling SH target functions.
3729 show debug timestamp
3730 Control display of timestamps with GDB debugging output.
3732 set disassemble-next-line
3733 show disassemble-next-line
3734 Control display of disassembled source lines or instructions when
3737 set remote noack-packet
3738 show remote noack-packet
3739 Set/show the use of remote protocol QStartNoAckMode packet. See above
3740 under "New remote packets."
3742 set remote query-attached-packet
3743 show remote query-attached-packet
3744 Control use of remote protocol `qAttached' (query-attached) packet.
3746 set remote read-siginfo-object
3747 show remote read-siginfo-object
3748 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3751 set remote write-siginfo-object
3752 show remote write-siginfo-object
3753 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3756 set remote reverse-continue
3757 show remote reverse-continue
3758 Control use of remote protocol 'bc' (reverse-continue) packet.
3760 set remote reverse-step
3761 show remote reverse-step
3762 Control use of remote protocol 'bs' (reverse-step) packet.
3764 set displaced-stepping
3765 show displaced-stepping
3766 Control displaced stepping mode. Displaced stepping is a way to
3767 single-step over breakpoints without removing them from the debuggee.
3768 Also known as "out-of-line single-stepping".
3771 show debug displaced
3772 Control display of debugging info for displaced stepping.
3774 maint set internal-error
3775 maint show internal-error
3776 Control what GDB does when an internal error is detected.
3778 maint set internal-warning
3779 maint show internal-warning
3780 Control what GDB does when an internal warning is detected.
3785 Use a wrapper program to launch programs for debugging.
3787 set multiple-symbols (all|ask|cancel)
3788 show multiple-symbols
3789 The value of this variable can be changed to adjust the debugger behavior
3790 when an expression or a breakpoint location contains an ambiguous symbol
3791 name (an overloaded function name, for instance).
3793 set breakpoint always-inserted
3794 show breakpoint always-inserted
3795 Keep breakpoints always inserted in the target, as opposed to inserting
3796 them when resuming the target, and removing them when the target stops.
3797 This option can improve debugger performance on slow remote targets.
3799 set arm fallback-mode (arm|thumb|auto)
3800 show arm fallback-mode
3801 set arm force-mode (arm|thumb|auto)
3803 These commands control how ARM GDB determines whether instructions
3804 are ARM or Thumb. The default for both settings is auto, which uses
3805 the current CPSR value for instructions without symbols; previous
3806 versions of GDB behaved as if "set arm fallback-mode arm".
3808 set disable-randomization
3809 show disable-randomization
3810 Standalone programs run with the virtual address space randomization enabled
3811 by default on some platforms. This option keeps the addresses stable across
3812 multiple debugging sessions.
3816 Control whether other threads are stopped or not when some thread hits
3821 Requests that asynchronous execution is enabled in the target, if available.
3822 In this case, it's possible to resume target in the background, and interact
3823 with GDB while the target is running. "show target-async" displays the
3824 current state of asynchronous execution of the target.
3826 set target-wide-charset
3827 show target-wide-charset
3828 The target-wide-charset is the name of the character set that GDB
3829 uses when printing characters whose type is wchar_t.
3831 set tcp auto-retry (on|off)
3833 set tcp connect-timeout
3834 show tcp connect-timeout
3835 These commands allow GDB to retry failed TCP connections to a remote stub
3836 with a specified timeout period; this is useful if the stub is launched
3837 in parallel with GDB but may not be ready to accept connections immediately.
3839 set libthread-db-search-path
3840 show libthread-db-search-path
3841 Control list of directories which GDB will search for appropriate
3844 set schedule-multiple (on|off)
3845 show schedule-multiple
3846 Allow GDB to resume all threads of all processes or only threads of
3847 the current process.
3851 Use more aggressive caching for accesses to the stack. This improves
3852 performance of remote debugging (particularly backtraces) without
3853 affecting correctness.
3855 set interactive-mode (on|off|auto)
3856 show interactive-mode
3857 Control whether GDB runs in interactive mode (on) or not (off).
3858 When in interactive mode, GDB waits for the user to answer all
3859 queries. Otherwise, GDB does not wait and assumes the default
3860 answer. When set to auto (the default), GDB determines which
3861 mode to use based on the stdin settings.
3866 For program forks, this is replaced by the new more generic `info
3867 inferiors' command. To list checkpoints, you can still use the
3868 `info checkpoints' command, which was an alias for the `info forks'
3872 Replaced by the new `inferior' command. To switch between
3873 checkpoints, you can still use the `restart' command, which was an
3874 alias for the `fork' command.
3877 This is removed, since some targets don't have a notion of
3878 processes. To switch between processes, you can still use the
3879 `inferior' command using GDB's own inferior number.
3882 For program forks, this is replaced by the new more generic `kill
3883 inferior' command. To delete a checkpoint, you can still use the
3884 `delete checkpoint' command, which was an alias for the `delete
3888 For program forks, this is replaced by the new more generic `detach
3889 inferior' command. To detach a checkpoint, you can still use the
3890 `detach checkpoint' command, which was an alias for the `detach
3893 * New native configurations
3895 x86/x86_64 Darwin i[34567]86-*-darwin*
3897 x86_64 MinGW x86_64-*-mingw*
3901 Lattice Mico32 lm32-*
3902 x86 DICOS i[34567]86-*-dicos*
3903 x86_64 DICOS x86_64-*-dicos*
3906 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3907 (mingw32ce) debugging.
3913 These commands were actually not implemented on any target.
3915 *** Changes in GDB 6.8
3917 * New native configurations
3919 NetBSD/hppa hppa*-*netbsd*
3920 Xtensa GNU/Linux xtensa*-*-linux*
3924 NetBSD/hppa hppa*-*-netbsd*
3925 Xtensa GNU/Lunux xtensa*-*-linux*
3927 * Change in command line behavior -- corefiles vs. process ids.
3929 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3930 attaching to process NUMBER fails, GDB no longer attempts to open a
3931 core file named NUMBER. Attaching to a program using the -c option
3932 is no longer supported. Instead, use the '-p' or '--pid' options.
3934 * GDB can now be built as a native debugger for debugging Windows x86
3935 (mingw32) Portable Executable (PE) programs.
3937 * Pending breakpoints no longer change their number when their address
3940 * GDB now supports breakpoints with multiple locations,
3941 including breakpoints on C++ constructors, inside C++ templates,
3942 and in inlined functions.
3944 * GDB's ability to debug optimized code has been improved. GDB more
3945 accurately identifies function bodies and lexical blocks that occupy
3946 more than one contiguous range of addresses.
3948 * Target descriptions can now describe registers for PowerPC.
3950 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3951 registers on PowerPC targets.
3953 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3954 targets even when the libthread_db library is not available.
3956 * The GDB remote stub, gdbserver, now supports the new file transfer
3957 commands (remote put, remote get, and remote delete).
3959 * The GDB remote stub, gdbserver, now supports run and attach in
3960 extended-remote mode.
3962 * hppa*64*-*-hpux11* target broken
3963 The debugger is unable to start a program and fails with the following
3964 error: "Error trying to get information about dynamic linker".
3965 The gdb-6.7 release is also affected.
3967 * GDB now supports the --enable-targets= configure option to allow
3968 building a single GDB executable that supports multiple remote
3969 target architectures.
3971 * GDB now supports debugging C and C++ programs which use the
3972 Decimal Floating Point extension. In addition, the PowerPC target
3973 now has a set of pseudo-registers to inspect decimal float values
3974 stored in two consecutive float registers.
3976 * The -break-insert MI command can optionally create pending
3979 * Improved support for debugging Ada
3980 Many improvements to the Ada language support have been made. These
3982 - Better support for Ada2005 interface types
3983 - Improved handling of arrays and slices in general
3984 - Better support for Taft-amendment types
3985 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3987 - Improved command completion in Ada
3990 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3995 set print frame-arguments (all|scalars|none)
3996 show print frame-arguments
3997 The value of this variable can be changed to control which argument
3998 values should be printed by the debugger when displaying a frame.
4003 Transfer files to and from a remote target, and delete remote files.
4010 Transfer files to and from a remote target, and delete remote files.
4012 * New remote packets
4019 Open, close, read, write, and delete files on the remote system.
4022 Attach to an existing process on the remote system, in extended-remote
4026 Run a new process on the remote system, in extended-remote mode.
4028 *** Changes in GDB 6.7
4030 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4031 bfd, libiberty and opcodes, as revealed by static analysis donated by
4032 Coverity, Inc. (http://scan.coverity.com).
4034 * When looking up multiply-defined global symbols, GDB will now prefer the
4035 symbol definition in the current shared library if it was built using the
4036 -Bsymbolic linker option.
4038 * When the Text User Interface (TUI) is not configured, GDB will now
4039 recognize the -tui command-line option and print a message that the TUI
4042 * The GDB remote stub, gdbserver, now has lower overhead for high
4043 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4045 * GDB for MIPS targets now autodetects whether a remote target provides
4046 32-bit or 64-bit register values.
4048 * Support for C++ member pointers has been improved.
4050 * GDB now understands XML target descriptions, which specify the
4051 target's overall architecture. GDB can read a description from
4052 a local file or over the remote serial protocol.
4054 * Vectors of single-byte data use a new integer type which is not
4055 automatically displayed as character or string data.
4057 * The /s format now works with the print command. It displays
4058 arrays of single-byte integers and pointers to single-byte integers
4061 * Target descriptions can now describe target-specific registers,
4062 for architectures which have implemented the support (currently
4063 only ARM, M68K, and MIPS).
4065 * GDB and the GDB remote stub, gdbserver, now support the XScale
4068 * The GDB remote stub, gdbserver, has been updated to support
4069 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4070 has been rewritten to use the standard GDB remote protocol.
4072 * GDB can now step into C++ functions which are called through thunks.
4074 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4076 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4077 layout. It also supports a TextSeg= and DataSeg= response when only
4078 segment base addresses (rather than offsets) are available.
4080 * The /i format now outputs any trailing branch delay slot instructions
4081 immediately following the last instruction within the count specified.
4083 * The GDB remote protocol "T" stop reply packet now supports a
4084 "library" response. Combined with the new "qXfer:libraries:read"
4085 packet, this response allows GDB to debug shared libraries on targets
4086 where the operating system manages the list of loaded libraries (e.g.
4087 Windows and SymbianOS).
4089 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4090 (DLLs) on Windows and Windows CE targets.
4092 * GDB now supports a faster verification that a .debug file matches its binary
4093 according to its build-id signature, if the signature is present.
4099 Enable or disable hardware flow control (RTS/CTS) on the serial port
4100 when debugging using remote targets.
4102 set mem inaccessible-by-default
4103 show mem inaccessible-by-default
4104 If the target supplies a memory map, for instance via the remote
4105 protocol's "qXfer:memory-map:read" packet, setting this variable
4106 prevents GDB from accessing memory outside the memory map. This
4107 is useful for targets with memory mapped registers or which react
4108 badly to accesses of unmapped address space.
4110 set breakpoint auto-hw
4111 show breakpoint auto-hw
4112 If the target supplies a memory map, for instance via the remote
4113 protocol's "qXfer:memory-map:read" packet, setting this variable
4114 lets GDB use hardware breakpoints automatically for memory regions
4115 where it can not use software breakpoints. This covers both the
4116 "break" command and internal breakpoints used for other commands
4117 including "next" and "finish".
4120 catch exception unhandled
4121 Stop the program execution when Ada exceptions are raised.
4124 Stop the program execution when an Ada assertion failed.
4128 Set an alternate system root for target files. This is a more
4129 general version of "set solib-absolute-prefix", which is now
4130 an alias to "set sysroot".
4133 Provide extended SPU facility status information. This set of
4134 commands is available only when debugging the Cell/B.E. SPU
4137 * New native configurations
4139 OpenBSD/sh sh*-*openbsd*
4142 unset tdesc filename
4144 Use the specified local file as an XML target description, and do
4145 not query the target for its built-in description.
4149 OpenBSD/sh sh*-*-openbsd*
4150 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4151 Toshiba Media Processor mep-elf
4153 * New remote packets
4156 Ignore the specified signals; pass them directly to the debugged program
4157 without stopping other threads or reporting them to GDB.
4159 qXfer:features:read:
4160 Read an XML target description from the target, which describes its
4165 Read or write contents of an spufs file on the target system. These
4166 packets are available only on the Cell/B.E. SPU architecture.
4168 qXfer:libraries:read:
4169 Report the loaded shared libraries. Combined with new "T" packet
4170 response, this packet allows GDB to debug shared libraries on
4171 targets where the operating system manages the list of loaded
4172 libraries (e.g. Windows and SymbianOS).
4176 Support for these obsolete configurations has been removed.
4184 i[34567]86-*-lynxos*
4185 i[34567]86-*-netware*
4186 i[34567]86-*-sco3.2v5*
4187 i[34567]86-*-sco3.2v4*
4189 i[34567]86-*-sysv4.2*
4192 i[34567]86-*-unixware2*
4193 i[34567]86-*-unixware*
4202 * Other removed features
4209 Various m68k-only ROM monitors.
4216 Various Renesas ROM monitors and debugging interfaces for SH and
4221 Support for a Macraigor serial interface to on-chip debugging.
4222 GDB does not directly support the newer parallel or USB
4227 A debug information format. The predecessor to DWARF 2 and
4228 DWARF 3, which are still supported.
4230 Support for the HP aCC compiler on HP-UX/PA-RISC
4232 SOM-encapsulated symbolic debugging information, automatic
4233 invocation of pxdb, and the aCC custom C++ ABI. This does not
4234 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4235 with aCC can still be debugged on an assembly level.
4237 MIPS ".pdr" sections
4239 A MIPS-specific format used to describe stack frame layout
4240 in debugging information.
4244 GDB could work with an older version of Guile to debug
4245 the interpreter and Scheme programs running in it.
4247 set mips stack-arg-size
4248 set mips saved-gpreg-size
4250 Use "set mips abi" to control parameter passing for MIPS.
4252 *** Changes in GDB 6.6
4257 Cell Broadband Engine SPU spu-elf
4259 * GDB can now be configured as a cross-debugger targeting native Windows
4260 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4261 running on a Windows system over TCP/IP to debug Windows programs.
4263 * The GDB remote stub, gdbserver, has been updated to support Windows and
4264 Cygwin debugging. Both single-threaded and multi-threaded programs are
4267 * The "set trust-readonly-sections" command works again. This command was
4268 broken in GDB 6.3, 6.4, and 6.5.
4270 * The "load" command now supports writing to flash memory, if the remote
4271 stub provides the required support.
4273 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4274 longer requires symbolic debug information (e.g. DWARF-2).
4279 unset substitute-path
4280 show substitute-path
4281 Manage a list of substitution rules that GDB uses to rewrite the name
4282 of the directories where the sources are located. This can be useful
4283 for instance when the sources were moved to a different location
4284 between compilation and debugging.
4288 Print each CLI command as it is executed. Each command is prefixed with
4289 a number of `+' symbols representing the nesting depth.
4290 The source command now has a `-v' option to enable the same feature.
4294 The ARM Demon monitor support (RDP protocol, "target rdp").
4296 Kernel Object Display, an embedded debugging feature which only worked with
4297 an obsolete version of Cisco IOS.
4299 The 'set download-write-size' and 'show download-write-size' commands.
4301 * New remote packets
4304 Tell a stub about GDB client features, and request remote target features.
4305 The first feature implemented is PacketSize, which allows the target to
4306 specify the size of packets it can handle - to minimize the number of
4307 packets required and improve performance when connected to a remote
4311 Fetch an OS auxilliary vector from the remote stub. This packet is a
4312 more efficient replacement for qPart:auxv:read.
4314 qXfer:memory-map:read:
4315 Fetch a memory map from the remote stub, including information about
4316 RAM, ROM, and flash memory devices.
4321 Erase and program a flash memory device.
4323 * Removed remote packets
4326 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4327 used it, and only gdbserver implemented it.
4329 *** Changes in GDB 6.5
4333 Renesas M32C/M16C m32c-elf
4335 Morpho Technologies ms1 ms1-elf
4339 init-if-undefined Initialize a convenience variable, but
4340 only if it doesn't already have a value.
4342 The following commands are presently only implemented for native GNU/Linux:
4344 checkpoint Save a snapshot of the program state.
4346 restart <n> Return the program state to a
4347 previously saved state.
4349 info checkpoints List currently saved checkpoints.
4351 delete-checkpoint <n> Delete a previously saved checkpoint.
4353 set|show detach-on-fork Tell gdb whether to detach from a newly
4354 forked process, or to keep debugging it.
4356 info forks List forks of the user program that
4357 are available to be debugged.
4359 fork <n> Switch to debugging one of several
4360 forks of the user program that are
4361 available to be debugged.
4363 delete-fork <n> Delete a fork from the list of forks
4364 that are available to be debugged (and
4365 kill the forked process).
4367 detach-fork <n> Delete a fork from the list of forks
4368 that are available to be debugged (and
4369 allow the process to continue).
4373 Morpho Technologies ms2 ms1-elf
4375 * Improved Windows host support
4377 GDB now builds as a cross debugger hosted on i686-mingw32, including
4378 native console support, and remote communications using either
4379 network sockets or serial ports.
4381 * Improved Modula-2 language support
4383 GDB can now print most types in the Modula-2 syntax. This includes:
4384 basic types, set types, record types, enumerated types, range types,
4385 pointer types and ARRAY types. Procedure var parameters are correctly
4386 printed and hexadecimal addresses and character constants are also
4387 written in the Modula-2 syntax. Best results can be obtained by using
4388 GNU Modula-2 together with the -gdwarf-2 command line option.
4392 The ARM rdi-share module.
4394 The Netware NLM debug server.
4396 *** Changes in GDB 6.4
4398 * New native configurations
4400 OpenBSD/arm arm*-*-openbsd*
4401 OpenBSD/mips64 mips64-*-openbsd*
4405 Morpho Technologies ms1 ms1-elf
4407 * New command line options
4409 --batch-silent As for --batch, but totally silent.
4410 --return-child-result The debugger will exist with the same value
4411 the child (debugged) program exited with.
4412 --eval-command COMMAND, -ex COMMAND
4413 Execute a single GDB CLI command. This may be
4414 specified multiple times and in conjunction
4415 with the --command (-x) option.
4417 * Deprecated commands removed
4419 The following commands, that were deprecated in 2000, have been
4423 set|show arm disassembly-flavor set|show arm disassembler
4424 othernames set arm disassembler
4425 set|show remotedebug set|show debug remote
4426 set|show archdebug set|show debug arch
4427 set|show eventdebug set|show debug event
4430 * New BSD user-level threads support
4432 It is now possible to debug programs using the user-level threads
4433 library on OpenBSD and FreeBSD. Currently supported (target)
4436 FreeBSD/amd64 x86_64-*-freebsd*
4437 FreeBSD/i386 i386-*-freebsd*
4438 OpenBSD/i386 i386-*-openbsd*
4440 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4441 are not yet supported.
4443 * New support for Matsushita MN10300 w/sim added
4444 (Work in progress). mn10300-elf.
4446 * REMOVED configurations and files
4448 VxWorks and the XDR protocol *-*-vxworks
4449 Motorola MCORE mcore-*-*
4450 National Semiconductor NS32000 ns32k-*-*
4452 * New "set print array-indexes" command
4454 After turning this setting "on", GDB prints the index of each element
4455 when displaying arrays. The default is "off" to preserve the previous
4458 * VAX floating point support
4460 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4462 * User-defined command support
4464 In addition to using $arg0..$arg9 for argument passing, it is now possible
4465 to use $argc to determine now many arguments have been passed. See the
4466 section on user-defined commands in the user manual for more information.
4468 *** Changes in GDB 6.3:
4470 * New command line option
4472 GDB now accepts -l followed by a number to set the timeout for remote
4475 * GDB works with GCC -feliminate-dwarf2-dups
4477 GDB now supports a more compact representation of DWARF-2 debug
4478 information using DW_FORM_ref_addr references. These are produced
4479 by GCC with the option -feliminate-dwarf2-dups and also by some
4480 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4481 to use -feliminate-dwarf2-dups.
4483 * Internationalization
4485 When supported by the host system, GDB will be built with
4486 internationalization (libintl). The task of marking up the sources is
4487 continued, we're looking forward to our first translation.
4491 Initial support for debugging programs compiled with the GNAT
4492 implementation of the Ada programming language has been integrated
4493 into GDB. In this release, support is limited to expression evaluation.
4495 * New native configurations
4497 GNU/Linux/m32r m32r-*-linux-gnu
4501 GDB's remote protocol now includes support for the 'p' packet. This
4502 packet is used to fetch individual registers from a remote inferior.
4504 * END-OF-LIFE registers[] compatibility module
4506 GDB's internal register infrastructure has been completely rewritten.
4507 The new infrastructure making possible the implementation of key new
4508 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4511 GDB 6.3 will be the last release to include the the registers[]
4512 compatibility module that allowed out-of-date configurations to
4513 continue to work. This change directly impacts the following
4523 powerpc bdm protocol
4525 Unless there is activity to revive these configurations, they will be
4526 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4528 * OBSOLETE configurations and files
4530 Configurations that have been declared obsolete in this release have
4531 been commented out. Unless there is activity to revive these
4532 configurations, the next release of GDB will have their sources
4533 permanently REMOVED.
4542 *** Changes in GDB 6.2.1:
4544 * MIPS `break main; run' gave an heuristic-fence-post warning
4546 When attempting to run even a simple program, a warning about
4547 heuristic-fence-post being hit would be reported. This problem has
4550 * MIPS IRIX 'long double' crashed GDB
4552 When examining a long double variable, GDB would get a segmentation
4553 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4554 IRIX long double values).
4558 A bug in the VAX stack code was causing problems with the "next"
4559 command. This problem has been fixed.
4561 *** Changes in GDB 6.2:
4563 * Fix for ``many threads''
4565 On GNU/Linux systems that use the NPTL threads library, a program
4566 rapidly creating and deleting threads would confuse GDB leading to the
4569 ptrace: No such process.
4570 thread_db_get_info: cannot get thread info: generic error
4572 This problem has been fixed.
4574 * "-async" and "-noasync" options removed.
4576 Support for the broken "-noasync" option has been removed (it caused
4579 * New ``start'' command.
4581 This command runs the program until the begining of the main procedure.
4583 * New BSD Kernel Data Access Library (libkvm) interface
4585 Using ``target kvm'' it is now possible to debug kernel core dumps and
4586 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4587 platforms. Currently supported (native-only) configurations are:
4589 FreeBSD/amd64 x86_64-*-freebsd*
4590 FreeBSD/i386 i?86-*-freebsd*
4591 NetBSD/i386 i?86-*-netbsd*
4592 NetBSD/m68k m68*-*-netbsd*
4593 NetBSD/sparc sparc-*-netbsd*
4594 OpenBSD/amd64 x86_64-*-openbsd*
4595 OpenBSD/i386 i?86-*-openbsd*
4596 OpenBSD/m68k m68*-openbsd*
4597 OpenBSD/sparc sparc-*-openbsd*
4599 * Signal trampoline code overhauled
4601 Many generic problems with GDB's signal handling code have been fixed.
4602 These include: backtraces through non-contiguous stacks; recognition
4603 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4604 call; backtrace through a signal trampoline; step into and out of
4605 signal handlers; and single-stepping in the signal trampoline.
4607 Please note that kernel bugs are a limiting factor here. These
4608 features have been shown to work on an s390 GNU/Linux system that
4609 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4611 * Cygwin support for DWARF 2 added.
4613 * New native configurations
4615 GNU/Linux/hppa hppa*-*-linux*
4616 OpenBSD/hppa hppa*-*-openbsd*
4617 OpenBSD/m68k m68*-*-openbsd*
4618 OpenBSD/m88k m88*-*-openbsd*
4619 OpenBSD/powerpc powerpc-*-openbsd*
4620 NetBSD/vax vax-*-netbsd*
4621 OpenBSD/vax vax-*-openbsd*
4623 * END-OF-LIFE frame compatibility module
4625 GDB's internal frame infrastructure has been completely rewritten.
4626 The new infrastructure making it possible to support key new features
4627 including DWARF 2 Call Frame Information. To aid in the task of
4628 migrating old configurations to this new infrastructure, a
4629 compatibility module, that allowed old configurations to continue to
4630 work, was also included.
4632 GDB 6.2 will be the last release to include this frame compatibility
4633 module. This change directly impacts the following configurations:
4643 Unless there is activity to revive these configurations, they will be
4644 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4646 * REMOVED configurations and files
4648 Sun 3, running SunOS 3 m68*-*-sunos3*
4649 Sun 3, running SunOS 4 m68*-*-sunos4*
4650 Sun 2, running SunOS 3 m68000-*-sunos3*
4651 Sun 2, running SunOS 4 m68000-*-sunos4*
4652 Motorola 680x0 running LynxOS m68*-*-lynxos*
4653 AT&T 3b1/Unix pc m68*-att-*
4654 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4655 decstation mips-dec-* mips-little-*
4656 riscos mips-*-riscos* mips-*-sysv*
4657 sonymips mips-sony-*
4658 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4660 *** Changes in GDB 6.1.1:
4662 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4664 The TUI (Text-mode User Interface) is now built as part of a default
4665 GDB configuration. It is enabled by either selecting the TUI with the
4666 command line option "-i=tui" or by running the separate "gdbtui"
4667 program. For more information on the TUI, see the manual "Debugging
4670 * Pending breakpoint support (also included in GDB 6.1)
4672 Support has been added to allow you to specify breakpoints in shared
4673 libraries that have not yet been loaded. If a breakpoint location
4674 cannot be found, and the "breakpoint pending" option is set to auto,
4675 GDB queries you if you wish to make the breakpoint pending on a future
4676 shared-library load. If and when GDB resolves the breakpoint symbol,
4677 the pending breakpoint is removed as one or more regular breakpoints
4680 Pending breakpoints are very useful for GCJ Java debugging.
4682 * Fixed ISO-C build problems
4684 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4685 non ISO-C code that stopped them being built using a more strict ISO-C
4686 compiler (e.g., IBM's C compiler).
4688 * Fixed build problem on IRIX 5
4690 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4691 wasn't able to compile compile on an IRIX 5 system.
4693 * Added execute permission to gdb/gdbserver/configure
4695 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4696 permission. This bug would cause configure to fail on a number of
4697 systems (Solaris, IRIX). Ref: server/519.
4699 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4701 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4702 has been updated to use constant array sizes.
4704 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4706 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4707 its generated DWARF Call Frame Info. This encoding was causing GDB to
4708 panic, that panic has been fixed. Ref: gdb/1628.
4710 * Fixed a problem when examining parameters in shared library code.
4712 When examining parameters in optimized shared library code generated
4713 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4714 not available''. GDB now correctly displays the variable's value.
4716 *** Changes in GDB 6.1:
4718 * Removed --with-mmalloc
4720 Support for the mmalloc memory manager has been removed, as it
4721 conflicted with the internal gdb byte cache.
4723 * Changes in AMD64 configurations
4725 The AMD64 target now includes the %cs and %ss registers. As a result
4726 the AMD64 remote protocol has changed; this affects the floating-point
4727 and SSE registers. If you rely on those registers for your debugging,
4728 you should upgrade gdbserver on the remote side.
4730 * Revised SPARC target
4732 The SPARC target has been completely revised, incorporating the
4733 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4734 support for LynxOS and SunOS 4 has been dropped. Calling functions
4735 from within GDB on operating systems with a non-executable stack
4736 (Solaris, OpenBSD) now works.
4740 GDB has a new C++ demangler which does a better job on the mangled
4741 names generated by current versions of g++. It also runs faster, so
4742 with this and other changes gdb should now start faster on large C++
4745 * DWARF 2 Location Expressions
4747 GDB support for location expressions has been extended to support function
4748 arguments and frame bases. Older versions of GDB could crash when they
4751 * C++ nested types and namespaces
4753 GDB's support for nested types and namespaces in C++ has been
4754 improved, especially if you use the DWARF 2 debugging format. (This
4755 is the default for recent versions of GCC on most platforms.)
4756 Specifically, if you have a class "Inner" defined within a class or
4757 namespace "Outer", then GDB realizes that the class's name is
4758 "Outer::Inner", not simply "Inner". This should greatly reduce the
4759 frequency of complaints about not finding RTTI symbols. In addition,
4760 if you are stopped at inside of a function defined within a namespace,
4761 GDB modifies its name lookup accordingly.
4763 * New native configurations
4765 NetBSD/amd64 x86_64-*-netbsd*
4766 OpenBSD/amd64 x86_64-*-openbsd*
4767 OpenBSD/alpha alpha*-*-openbsd*
4768 OpenBSD/sparc sparc-*-openbsd*
4769 OpenBSD/sparc64 sparc64-*-openbsd*
4771 * New debugging protocols
4773 M32R with SDI protocol m32r-*-elf*
4775 * "set prompt-escape-char" command deleted.
4777 The command "set prompt-escape-char" has been deleted. This command,
4778 and its very obscure effet on GDB's prompt, was never documented,
4779 tested, nor mentioned in the NEWS file.
4781 * OBSOLETE configurations and files
4783 Configurations that have been declared obsolete in this release have
4784 been commented out. Unless there is activity to revive these
4785 configurations, the next release of GDB will have their sources
4786 permanently REMOVED.
4788 Sun 3, running SunOS 3 m68*-*-sunos3*
4789 Sun 3, running SunOS 4 m68*-*-sunos4*
4790 Sun 2, running SunOS 3 m68000-*-sunos3*
4791 Sun 2, running SunOS 4 m68000-*-sunos4*
4792 Motorola 680x0 running LynxOS m68*-*-lynxos*
4793 AT&T 3b1/Unix pc m68*-att-*
4794 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4795 decstation mips-dec-* mips-little-*
4796 riscos mips-*-riscos* mips-*-sysv*
4797 sonymips mips-sony-*
4798 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4800 * REMOVED configurations and files
4802 SGI Irix-4.x mips-sgi-irix4 or iris4
4803 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4804 Z8000 simulator z8k-zilog-none or z8ksim
4805 Matsushita MN10200 w/simulator mn10200-*-*
4806 H8/500 simulator h8500-hitachi-hms or h8500hms
4807 HP/PA running BSD hppa*-*-bsd*
4808 HP/PA running OSF/1 hppa*-*-osf*
4809 HP/PA Pro target hppa*-*-pro*
4810 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4811 386BSD i[3456]86-*-bsd*
4812 Sequent family i[3456]86-sequent-sysv4*
4813 i[3456]86-sequent-sysv*
4814 i[3456]86-sequent-bsd*
4815 SPARC running LynxOS sparc-*-lynxos*
4816 SPARC running SunOS 4 sparc-*-sunos4*
4817 Tsqware Sparclet sparclet-*-*
4818 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4820 *** Changes in GDB 6.0:
4824 Support for debugging the Objective-C programming language has been
4825 integrated into GDB.
4827 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4829 DWARF 2's Call Frame Information makes available compiler generated
4830 information that more exactly describes the program's run-time stack.
4831 By using this information, GDB is able to provide more robust stack
4834 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4835 have been updated to use a new backtrace mechanism which includes
4836 DWARF 2 CFI support.
4840 GDB's remote protocol has been extended to include support for hosted
4841 file I/O (where the remote target uses GDB's file system). See GDB's
4842 remote protocol documentation for details.
4844 * All targets using the new architecture framework.
4846 All of GDB's targets have been updated to use the new internal
4847 architecture framework. The way is now open for future GDB releases
4848 to include cross-architecture native debugging support (i386 on amd64,
4851 * GNU/Linux's Thread Local Storage (TLS)
4853 GDB now includes support for for the GNU/Linux implementation of
4854 per-thread variables.
4856 * GNU/Linux's Native POSIX Thread Library (NPTL)
4858 GDB's thread code has been updated to work with either the new
4859 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4861 * Separate debug info.
4863 GDB, in conjunction with BINUTILS, now supports a mechanism for
4864 automatically loading debug information from a separate file. Instead
4865 of shipping full debug and non-debug versions of system libraries,
4866 system integrators can now instead ship just the stripped libraries
4867 and optional debug files.
4869 * DWARF 2 Location Expressions
4871 DWARF 2 Location Expressions allow the compiler to more completely
4872 describe the location of variables (even in optimized code) to the
4875 GDB now includes preliminary support for location expressions (support
4876 for DW_OP_piece is still missing).
4880 A number of long standing bugs that caused GDB to die while starting a
4881 Java application have been fixed. GDB's Java support is now
4882 considered "useable".
4884 * GNU/Linux support for fork, vfork, and exec.
4886 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4887 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4890 * GDB supports logging output to a file
4892 There are two new commands, "set logging" and "show logging", which can be
4893 used to capture GDB's output to a file.
4895 * The meaning of "detach" has changed for gdbserver
4897 The "detach" command will now resume the application, as documented. To
4898 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4901 * d10v, m68hc11 `regs' command deprecated
4903 The `info registers' command has been updated so that it displays the
4904 registers using a format identical to the old `regs' command.
4908 A new command, "maint set profile on/off", has been added. This command can
4909 be used to enable or disable profiling while running GDB, to profile a
4910 session or a set of commands. In addition there is a new configure switch,
4911 "--enable-profiling", which will cause GDB to be compiled with profiling
4912 data, for more informative profiling results.
4914 * Default MI syntax changed to "mi2".
4916 The default MI (machine interface) syntax, enabled by the command line
4917 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4918 "mi1", can be enabled by specifying the option "-i=mi1".
4920 Support for the original "mi0" syntax (included in GDB 5.0) has been
4923 Fix for gdb/192: removed extraneous space when displaying frame level.
4924 Fix for gdb/672: update changelist is now output in mi list format.
4925 Fix for gdb/702: a -var-assign that updates the value now shows up
4926 in a subsequent -var-update.
4928 * New native configurations.
4930 FreeBSD/amd64 x86_64-*-freebsd*
4932 * Multi-arched targets.
4934 HP/PA HPUX11 hppa*-*-hpux*
4935 Renesas M32R/D w/simulator m32r-*-elf*
4937 * OBSOLETE configurations and files
4939 Configurations that have been declared obsolete in this release have
4940 been commented out. Unless there is activity to revive these
4941 configurations, the next release of GDB will have their sources
4942 permanently REMOVED.
4944 Z8000 simulator z8k-zilog-none or z8ksim
4945 Matsushita MN10200 w/simulator mn10200-*-*
4946 H8/500 simulator h8500-hitachi-hms or h8500hms
4947 HP/PA running BSD hppa*-*-bsd*
4948 HP/PA running OSF/1 hppa*-*-osf*
4949 HP/PA Pro target hppa*-*-pro*
4950 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4951 Sequent family i[3456]86-sequent-sysv4*
4952 i[3456]86-sequent-sysv*
4953 i[3456]86-sequent-bsd*
4954 Tsqware Sparclet sparclet-*-*
4955 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4957 * REMOVED configurations and files
4960 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4961 IBM AIX PS/2 i[3456]86-*-aix
4962 i386 running Mach 3.0 i[3456]86-*-mach3*
4963 i386 running Mach i[3456]86-*-mach*
4964 i386 running OSF/1 i[3456]86-*osf1mk*
4965 HP/Apollo 68k Family m68*-apollo*-sysv*,
4967 m68*-hp-bsd*, m68*-hp-hpux*
4968 Argonaut Risc Chip (ARC) arc-*-*
4969 Mitsubishi D30V d30v-*-*
4970 Fujitsu FR30 fr30-*-elf*
4971 OS/9000 i[34]86-*-os9k
4972 I960 with MON960 i960-*-coff
4974 * MIPS $fp behavior changed
4976 The convenience variable $fp, for the MIPS, now consistently returns
4977 the address of the current frame's base. Previously, depending on the
4978 context, $fp could refer to either $sp or the current frame's base
4979 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4980 The GNU Source-Level Debugger''.
4982 *** Changes in GDB 5.3:
4984 * GNU/Linux shared library multi-threaded performance improved.
4986 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4987 `/proc', in preference to `ptrace' for memory reads. This may result
4988 in an improvement in the start-up time of multi-threaded, shared
4989 library applications when run under GDB. One GDB user writes: ``loads
4990 shared libs like mad''.
4992 * ``gdbserver'' now supports multi-threaded applications on some targets
4994 Support for debugging multi-threaded applications which use
4995 the GNU/Linux LinuxThreads package has been added for
4996 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4997 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4999 * GDB now supports C/C++ preprocessor macros.
5001 GDB now expands preprocessor macro invocations in C/C++ expressions,
5002 and provides various commands for showing macro definitions and how
5005 The new command `macro expand EXPRESSION' expands any macro
5006 invocations in expression, and shows the result.
5008 The new command `show macro MACRO-NAME' shows the definition of the
5009 macro named MACRO-NAME, and where it was defined.
5011 Most compilers don't include information about macros in the debugging
5012 information by default. In GCC 3.1, for example, you need to compile
5013 your program with the options `-gdwarf-2 -g3'. If the macro
5014 information is present in the executable, GDB will read it.
5016 * Multi-arched targets.
5018 DEC Alpha (partial) alpha*-*-*
5019 DEC VAX (partial) vax-*-*
5021 National Semiconductor NS32000 (partial) ns32k-*-*
5022 Motorola 68000 (partial) m68k-*-*
5023 Motorola MCORE mcore-*-*
5027 Fujitsu FRV architecture added by Red Hat frv*-*-*
5030 * New native configurations
5032 Alpha NetBSD alpha*-*-netbsd*
5033 SH NetBSD sh*-*-netbsdelf*
5034 MIPS NetBSD mips*-*-netbsd*
5035 UltraSPARC NetBSD sparc64-*-netbsd*
5037 * OBSOLETE configurations and files
5039 Configurations that have been declared obsolete in this release have
5040 been commented out. Unless there is activity to revive these
5041 configurations, the next release of GDB will have their sources
5042 permanently REMOVED.
5044 Mitsubishi D30V d30v-*-*
5045 OS/9000 i[34]86-*-os9k
5046 IBM AIX PS/2 i[3456]86-*-aix
5047 Fujitsu FR30 fr30-*-elf*
5048 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5049 Argonaut Risc Chip (ARC) arc-*-*
5050 i386 running Mach 3.0 i[3456]86-*-mach3*
5051 i386 running Mach i[3456]86-*-mach*
5052 i386 running OSF/1 i[3456]86-*osf1mk*
5053 HP/Apollo 68k Family m68*-apollo*-sysv*,
5055 m68*-hp-bsd*, m68*-hp-hpux*
5056 I960 with MON960 i960-*-coff
5058 * OBSOLETE languages
5060 CHILL, a Pascal like language used by telecommunications companies.
5062 * REMOVED configurations and files
5064 AMD 29k family via UDI a29k-amd-udi, udi29k
5065 A29K VxWorks a29k-*-vxworks
5066 AMD 29000 embedded, using EBMON a29k-none-none
5067 AMD 29000 embedded with COFF a29k-none-coff
5068 AMD 29000 embedded with a.out a29k-none-aout
5070 testsuite/gdb.hp/gdb.threads-hp/ directory
5072 * New command "set max-user-call-depth <nnn>"
5074 This command allows the user to limit the call depth of user-defined
5075 commands. The default is 1024.
5077 * Changes in FreeBSD/i386 native debugging.
5079 Support for the "generate-core-file" has been added.
5081 * New commands "dump", "append", and "restore".
5083 These commands allow data to be copied from target memory
5084 to a bfd-format or binary file (dump and append), and back
5085 from a file into memory (restore).
5087 * Improved "next/step" support on multi-processor Alpha Tru64.
5089 The previous single-step mechanism could cause unpredictable problems,
5090 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5091 of a software single-step mechanism prevents this.
5093 *** Changes in GDB 5.2.1:
5101 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5102 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5103 Fix, by Joel Brobecker imported from mainline.
5105 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5106 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5107 Fix, by Fred Fish, imported from mainline.
5109 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5110 Surprisingly enough, it works now.
5111 By Michal Ludvig, imported from mainline.
5113 i386 hardware watchpoint support:
5114 avoid misses on second run for some targets.
5115 By Pierre Muller, imported from mainline.
5117 *** Changes in GDB 5.2:
5119 * New command "set trust-readonly-sections on[off]".
5121 This command is a hint that tells gdb that read-only sections
5122 really are read-only (ie. that their contents will not change).
5123 In this mode, gdb will go to the object file rather than the
5124 target to read memory from read-only sections (such as ".text").
5125 This can be a significant performance improvement on some
5126 (notably embedded) targets.
5128 * New command "generate-core-file" (or "gcore").
5130 This new gdb command allows the user to drop a core file of the child
5131 process state at any time. So far it's been implemented only for
5132 GNU/Linux and Solaris, but should be relatively easily ported to other
5133 hosts. Argument is core file name (defaults to core.<pid>).
5135 * New command line option
5137 GDB now accepts --pid or -p followed by a process id.
5139 * Change in command line behavior -- corefiles vs. process ids.
5141 There is a subtle behavior in the way in which GDB handles
5142 command line arguments. The first non-flag argument is always
5143 a program to debug, but the second non-flag argument may either
5144 be a corefile or a process id. Previously, GDB would attempt to
5145 open the second argument as a corefile, and if that failed, would
5146 issue a superfluous error message and then attempt to attach it as
5147 a process. Now, if the second argument begins with a non-digit,
5148 it will be treated as a corefile. If it begins with a digit,
5149 GDB will attempt to attach it as a process, and if no such process
5150 is found, will then attempt to open it as a corefile.
5152 * Changes in ARM configurations.
5154 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5155 configuration is fully multi-arch.
5157 * New native configurations
5159 ARM NetBSD arm*-*-netbsd*
5160 x86 OpenBSD i[3456]86-*-openbsd*
5161 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5162 Sparc64 running FreeBSD sparc64-*-freebsd*
5166 Sanyo XStormy16 xstormy16-elf
5168 * OBSOLETE configurations and files
5170 Configurations that have been declared obsolete in this release have
5171 been commented out. Unless there is activity to revive these
5172 configurations, the next release of GDB will have their sources
5173 permanently REMOVED.
5175 AMD 29k family via UDI a29k-amd-udi, udi29k
5176 A29K VxWorks a29k-*-vxworks
5177 AMD 29000 embedded, using EBMON a29k-none-none
5178 AMD 29000 embedded with COFF a29k-none-coff
5179 AMD 29000 embedded with a.out a29k-none-aout
5181 testsuite/gdb.hp/gdb.threads-hp/ directory
5183 * REMOVED configurations and files
5185 TI TMS320C80 tic80-*-*
5187 PowerPC Solaris powerpcle-*-solaris*
5188 PowerPC Windows NT powerpcle-*-cygwin32
5189 PowerPC Netware powerpc-*-netware*
5190 Harris/CXUX m88k m88*-harris-cxux*
5191 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5192 ns32k-utek-sysv* ns32k-utek-*
5193 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5194 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5195 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5196 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5197 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5199 * Changes to command line processing
5201 The new `--args' feature can be used to specify command-line arguments
5202 for the inferior from gdb's command line.
5204 * Changes to key bindings
5206 There is a new `operate-and-get-next' function bound to `C-o'.
5208 *** Changes in GDB 5.1.1
5210 Fix compile problem on DJGPP.
5212 Fix a problem with floating-point registers on the i386 being
5215 Fix to stop GDB crashing on .debug_str debug info.
5217 Numerous documentation fixes.
5219 Numerous testsuite fixes.
5221 *** Changes in GDB 5.1:
5223 * New native configurations
5225 Alpha FreeBSD alpha*-*-freebsd*
5226 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5227 MIPS GNU/Linux mips*-*-linux*
5228 MIPS SGI Irix 6.x mips*-sgi-irix6*
5229 ia64 AIX ia64-*-aix*
5230 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5234 Motorola 68HC11 and 68HC12 m68hc11-elf
5236 UltraSparc running GNU/Linux sparc64-*-linux*
5238 * OBSOLETE configurations and files
5240 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5241 Harris/CXUX m88k m88*-harris-cxux*
5242 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5243 ns32k-utek-sysv* ns32k-utek-*
5244 TI TMS320C80 tic80-*-*
5246 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5247 PowerPC Solaris powerpcle-*-solaris*
5248 PowerPC Windows NT powerpcle-*-cygwin32
5249 PowerPC Netware powerpc-*-netware*
5250 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5251 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5252 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5253 Apple Macintosh (MPW) host N/A
5255 stuff.c (Program to stuff files into a specially prepared space in kdb)
5256 kdb-start.c (Main loop for the standalone kernel debugger)
5258 Configurations that have been declared obsolete in this release have
5259 been commented out. Unless there is activity to revive these
5260 configurations, the next release of GDB will have their sources
5261 permanently REMOVED.
5263 * REMOVED configurations and files
5265 Altos 3068 m68*-altos-*
5266 Convex c1-*-*, c2-*-*
5268 ARM RISCix arm-*-* (as host)
5272 * GDB has been converted to ISO C.
5274 GDB's source code has been converted to ISO C. In particular, the
5275 sources are fully protoized, and rely on standard headers being
5280 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5282 * The MI enabled by default.
5284 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5285 revised and enabled by default. Packages which use GDB as a debugging
5286 engine behind a UI or another front end are encouraged to switch to
5287 using the GDB/MI interface, instead of the old annotations interface
5288 which is now deprecated.
5290 * Support for debugging Pascal programs.
5292 GDB now includes support for debugging Pascal programs. The following
5293 main features are supported:
5295 - Pascal-specific data types such as sets;
5297 - automatic recognition of Pascal sources based on file-name
5300 - Pascal-style display of data types, variables, and functions;
5302 - a Pascal expression parser.
5304 However, some important features are not yet supported.
5306 - Pascal string operations are not supported at all;
5308 - there are some problems with boolean types;
5310 - Pascal type hexadecimal constants are not supported
5311 because they conflict with the internal variables format;
5313 - support for Pascal objects and classes is not full yet;
5315 - unlike Pascal, GDB is case-sensitive for symbol names.
5317 * Changes in completion.
5319 Commands such as `shell', `run' and `set args', which pass arguments
5320 to inferior programs, now complete on file names, similar to what
5321 users expect at the shell prompt.
5323 Commands which accept locations, such as `disassemble', `print',
5324 `breakpoint', `until', etc. now complete on filenames as well as
5325 program symbols. Thus, if you type "break foob TAB", and the source
5326 files linked into the programs include `foobar.c', that file name will
5327 be one of the candidates for completion. However, file names are not
5328 considered for completion after you typed a colon that delimits a file
5329 name from a name of a function in that file, as in "break foo.c:bar".
5331 `set demangle-style' completes on available demangling styles.
5333 * New platform-independent commands:
5335 It is now possible to define a post-hook for a command as well as a
5336 hook that runs before the command. For more details, see the
5337 documentation of `hookpost' in the GDB manual.
5339 * Changes in GNU/Linux native debugging.
5341 Support for debugging multi-threaded programs has been completely
5342 revised for all platforms except m68k and sparc. You can now debug as
5343 many threads as your system allows you to have.
5345 Attach/detach is supported for multi-threaded programs.
5347 Support for SSE registers was added for x86. This doesn't work for
5348 multi-threaded programs though.
5350 * Changes in MIPS configurations.
5352 Multi-arch support is enabled for all MIPS configurations.
5354 GDB can now be built as native debugger on SGI Irix 6.x systems for
5355 debugging n32 executables. (Debugging 64-bit executables is not yet
5358 * Unified support for hardware watchpoints in all x86 configurations.
5360 Most (if not all) native x86 configurations support hardware-assisted
5361 breakpoints and watchpoints in a unified manner. This support
5362 implements debug register sharing between watchpoints, which allows to
5363 put a virtually infinite number of watchpoints on the same address,
5364 and also supports watching regions up to 16 bytes with several debug
5367 The new maintenance command `maintenance show-debug-regs' toggles
5368 debugging print-outs in functions that insert, remove, and test
5369 watchpoints and hardware breakpoints.
5371 * Changes in the DJGPP native configuration.
5373 New command ``info dos sysinfo'' displays assorted information about
5374 the CPU, OS, memory, and DPMI server.
5376 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5377 display information about segment descriptors stored in GDT, LDT, and
5380 New commands ``info dos pde'' and ``info dos pte'' display entries
5381 from Page Directory and Page Tables (for now works with CWSDPMI only).
5382 New command ``info dos address-pte'' displays the Page Table entry for
5383 a given linear address.
5385 GDB can now pass command lines longer than 126 characters to the
5386 program being debugged (requires an update to the libdbg.a library
5387 which is part of the DJGPP development kit).
5389 DWARF2 debug info is now supported.
5391 It is now possible to `step' and `next' through calls to `longjmp'.
5393 * Changes in documentation.
5395 All GDB documentation was converted to GFDL, the GNU Free
5396 Documentation License.
5398 Tracepoints-related commands are now fully documented in the GDB
5401 TUI, the Text-mode User Interface, is now documented in the manual.
5403 Tracepoints-related commands are now fully documented in the GDB
5406 The "GDB Internals" manual now has an index. It also includes
5407 documentation of `ui_out' functions, GDB coding standards, x86
5408 hardware watchpoints, and memory region attributes.
5410 * GDB's version number moved to ``version.in''
5412 The Makefile variable VERSION has been replaced by the file
5413 ``version.in''. People creating GDB distributions should update the
5414 contents of this file.
5418 GUD support is now a standard part of the EMACS distribution.
5420 *** Changes in GDB 5.0:
5422 * Improved support for debugging FP programs on x86 targets
5424 Unified and much-improved support for debugging floating-point
5425 programs on all x86 targets. In particular, ``info float'' now
5426 displays the FP registers in the same format on all x86 targets, with
5427 greater level of detail.
5429 * Improvements and bugfixes in hardware-assisted watchpoints
5431 It is now possible to watch array elements, struct members, and
5432 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5433 on x86 targets no longer erroneously trigger when the address is
5436 * Improvements in the native DJGPP version of GDB
5438 The distribution now includes all the scripts and auxiliary files
5439 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5440 machines ``out of the box''.
5442 The DJGPP version can now debug programs that use signals. It is
5443 possible to catch signals that happened in the debuggee, deliver
5444 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5445 would kill the program being debugged.) Programs that hook hardware
5446 interrupts (keyboard, timer, etc.) can also be debugged.
5448 It is now possible to debug DJGPP programs that redirect their
5449 standard handles or switch them to raw (as opposed to cooked) mode, or
5450 even close them. The command ``run < foo > bar'' works as expected,
5451 and ``info terminal'' reports useful information about the debuggee's
5452 terminal, including raw/cooked mode, redirection, etc.
5454 The DJGPP version now uses termios functions for console I/O, which
5455 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5458 DOS-style file names with drive letters are now fully supported by
5461 It is now possible to debug DJGPP programs that switch their working
5462 directory. It is also possible to rerun the debuggee any number of
5463 times without restarting GDB; thus, you can use the same setup,
5464 breakpoints, etc. for many debugging sessions.
5466 * New native configurations
5468 ARM GNU/Linux arm*-*-linux*
5469 PowerPC GNU/Linux powerpc-*-linux*
5473 Motorola MCore mcore-*-*
5474 x86 VxWorks i[3456]86-*-vxworks*
5475 PowerPC VxWorks powerpc-*-vxworks*
5476 TI TMS320C80 tic80-*-*
5478 * OBSOLETE configurations
5480 Altos 3068 m68*-altos-*
5481 Convex c1-*-*, c2-*-*
5483 ARM RISCix arm-*-* (as host)
5486 Configurations that have been declared obsolete will be commented out,
5487 but the code will be left in place. If there is no activity to revive
5488 these configurations before the next release of GDB, the sources will
5489 be permanently REMOVED.
5491 * Gould support removed
5493 Support for the Gould PowerNode and NP1 has been removed.
5495 * New features for SVR4
5497 On SVR4 native platforms (such as Solaris), if you attach to a process
5498 without first loading a symbol file, GDB will now attempt to locate and
5499 load symbols from the running process's executable file.
5501 * Many C++ enhancements
5503 C++ support has been greatly improved. Overload resolution now works properly
5504 in almost all cases. RTTI support is on the way.
5506 * Remote targets can connect to a sub-program
5508 A popen(3) style serial-device has been added. This device starts a
5509 sub-process (such as a stand-alone simulator) and then communicates
5510 with that. The sub-program to run is specified using the syntax
5511 ``|<program> <args>'' vis:
5513 (gdb) set remotedebug 1
5514 (gdb) target extended-remote |mn10300-elf-sim program-args
5516 * MIPS 64 remote protocol
5518 A long standing bug in the mips64 remote protocol where by GDB
5519 expected certain 32 bit registers (ex SR) to be transfered as 32
5520 instead of 64 bits has been fixed.
5522 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5523 added to provide backward compatibility with older versions of GDB.
5525 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5527 The command ``set remotebinarydownload'' command has been replaced by
5528 ``set remote X-packet''. Other commands in ``set remote'' family
5529 include ``set remote P-packet''.
5531 * Breakpoint commands accept ranges.
5533 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5534 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5535 ``tracepoint passcount'' also accepts a range of tracepoints.
5537 * ``apropos'' command added.
5539 The ``apropos'' command searches through command names and
5540 documentation strings, printing out matches, making it much easier to
5541 try to find a command that does what you are looking for.
5545 A new machine oriented interface (MI) has been added to GDB. This
5546 interface is designed for debug environments running GDB as a separate
5547 process. This is part of the long term libGDB project. See the
5548 "GDB/MI" chapter of the GDB manual for further information. It can be
5549 enabled by configuring with:
5551 .../configure --enable-gdbmi
5553 *** Changes in GDB-4.18:
5555 * New native configurations
5557 HP-UX 10.20 hppa*-*-hpux10.20
5558 HP-UX 11.x hppa*-*-hpux11.0*
5559 M68K GNU/Linux m68*-*-linux*
5563 Fujitsu FR30 fr30-*-elf*
5564 Intel StrongARM strongarm-*-*
5565 Mitsubishi D30V d30v-*-*
5567 * OBSOLETE configurations
5569 Gould PowerNode, NP1 np1-*-*, pn-*-*
5571 Configurations that have been declared obsolete will be commented out,
5572 but the code will be left in place. If there is no activity to revive
5573 these configurations before the next release of GDB, the sources will
5574 be permanently REMOVED.
5578 As a compatibility experiment, GDB's source files buildsym.h and
5579 buildsym.c have been converted to pure standard C, no longer
5580 containing any K&R compatibility code. We believe that all systems in
5581 use today either come with a standard C compiler, or have a GCC port
5582 available. If this is not true, please report the affected
5583 configuration to bug-gdb@gnu.org immediately. See the README file for
5584 information about getting a standard C compiler if you don't have one
5589 GDB now uses readline 2.2.
5591 * set extension-language
5593 You can now control the mapping between filename extensions and source
5594 languages by using the `set extension-language' command. For instance,
5595 you can ask GDB to treat .c files as C++ by saying
5596 set extension-language .c c++
5597 The command `info extensions' lists all of the recognized extensions
5598 and their associated languages.
5600 * Setting processor type for PowerPC and RS/6000
5602 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5603 you can use the `set processor' command to specify what variant of the
5604 PowerPC family you are debugging. The command
5608 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5609 following PowerPC and RS6000 variants:
5611 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5612 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5614 403GC IBM PowerPC 403GC
5615 505 Motorola PowerPC 505
5616 860 Motorola PowerPC 860 or 850
5617 601 Motorola PowerPC 601
5618 602 Motorola PowerPC 602
5619 603 Motorola/IBM PowerPC 603 or 603e
5620 604 Motorola PowerPC 604 or 604e
5621 750 Motorola/IBM PowerPC 750 or 750
5623 At the moment, this command just tells GDB what to name the
5624 special-purpose processor registers. Since almost all the affected
5625 registers are inaccessible to user-level programs, this command is
5626 only useful for remote debugging in its present form.
5630 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5631 more extensive support for HP-UX. Added features include shared
5632 library support, kernel threads and hardware watchpoints for 11.00,
5633 support for HP's ANSI C and C++ compilers, and a compatibility mode
5634 for xdb and dbx commands.
5638 HP's donation includes the new concept of catchpoints, which is a
5639 generalization of the old catch command. On HP-UX, it is now possible
5640 to catch exec, fork, and vfork, as well as library loading.
5642 This means that the existing catch command has changed; its first
5643 argument now specifies the type of catch to be set up. See the
5644 output of "help catch" for a list of catchpoint types.
5646 * Debugging across forks
5648 On HP-UX, you can choose which process to debug when a fork() happens
5653 HP has donated a curses-based terminal user interface (TUI). To get
5654 it, build with --enable-tui. Although this can be enabled for any
5655 configuration, at present it only works for native HP debugging.
5657 * GDB remote protocol additions
5659 A new protocol packet 'X' that writes binary data is now available.
5660 Default behavior is to try 'X', then drop back to 'M' if the stub
5661 fails to respond. The settable variable `remotebinarydownload'
5662 allows explicit control over the use of 'X'.
5664 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5665 full 64-bit address. The command
5667 set remoteaddresssize 32
5669 can be used to revert to the old behaviour. For existing remote stubs
5670 the change should not be noticed, as the additional address information
5673 In order to assist in debugging stubs, you may use the maintenance
5674 command `packet' to send any text string to the stub. For instance,
5676 maint packet heythere
5678 sends the packet "$heythere#<checksum>". Note that it is very easy to
5679 disrupt a debugging session by sending the wrong packet at the wrong
5682 The compare-sections command allows you to compare section data on the
5683 target to what is in the executable file without uploading or
5684 downloading, by comparing CRC checksums.
5686 * Tracing can collect general expressions
5688 You may now collect general expressions at tracepoints. This requires
5689 further additions to the target-side stub; see tracepoint.c and
5690 doc/agentexpr.texi for further details.
5692 * mask-address variable for Mips
5694 For Mips targets, you may control the zeroing of the upper 32 bits of
5695 a 64-bit address by entering `set mask-address on'. This is mainly
5696 of interest to users of embedded R4xxx and R5xxx processors.
5698 * Higher serial baud rates
5700 GDB's serial code now allows you to specify baud rates 57600, 115200,
5701 230400, and 460800 baud. (Note that your host system may not be able
5702 to achieve all of these rates.)
5706 The i960 configuration now includes an initial implementation of a
5707 builtin simulator, contributed by Jim Wilson.
5710 *** Changes in GDB-4.17:
5712 * New native configurations
5714 Alpha GNU/Linux alpha*-*-linux*
5715 Unixware 2.x i[3456]86-unixware2*
5716 Irix 6.x mips*-sgi-irix6*
5717 PowerPC GNU/Linux powerpc-*-linux*
5718 PowerPC Solaris powerpcle-*-solaris*
5719 Sparc GNU/Linux sparc-*-linux*
5720 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5724 Argonaut Risc Chip (ARC) arc-*-*
5725 Hitachi H8/300S h8300*-*-*
5726 Matsushita MN10200 w/simulator mn10200-*-*
5727 Matsushita MN10300 w/simulator mn10300-*-*
5728 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5729 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5730 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5731 Mitsubishi D10V w/simulator d10v-*-*
5732 Mitsubishi M32R/D w/simulator m32r-*-elf*
5733 Tsqware Sparclet sparclet-*-*
5734 NEC V850 w/simulator v850-*-*
5736 * New debugging protocols
5738 ARM with RDI protocol arm*-*-*
5739 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5740 DDB and LSI variants of PMON protocol mips*-*-*
5741 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5742 PowerPC with SDS protocol powerpc{,le}-*-eabi
5743 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5747 All configurations can now understand and use the DWARF 2 debugging
5748 format. The choice is automatic, if the symbol file contains DWARF 2
5753 GDB now includes basic Java language support. This support is
5754 only useful with Java compilers that produce native machine code.
5756 * solib-absolute-prefix and solib-search-path
5758 For SunOS and SVR4 shared libraries, you may now set the prefix for
5759 loading absolute shared library symbol files, and the search path for
5760 locating non-absolute shared library symbol files.
5762 * Live range splitting
5764 GDB can now effectively debug code for which GCC has performed live
5765 range splitting as part of its optimization. See gdb/doc/LRS for
5766 more details on the expected format of the stabs information.
5770 GDB's support for the GNU Hurd, including thread debugging, has been
5771 updated to work with current versions of the Hurd.
5775 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5776 instruction set. ARM GDB automatically detects when Thumb
5777 instructions are in use, and adjusts disassembly and backtracing
5782 GDB's MIPS target configurations now handle the MIP16 16-bit
5787 GDB now includes support for overlays; if an executable has been
5788 linked such that multiple sections are based at the same address, GDB
5789 will decide which section to use for symbolic info. You can choose to
5790 control the decision manually, using overlay commands, or implement
5791 additional target-side support and use "overlay load-target" to bring
5792 in the overlay mapping. Do "help overlay" for more detail.
5796 The command "info symbol <address>" displays information about
5797 the symbol at the specified address.
5801 The standard remote protocol now includes an extension that allows
5802 asynchronous collection and display of trace data. This requires
5803 extensive support in the target-side debugging stub. Tracing mode
5804 includes a new interaction mode in GDB and new commands: see the
5805 file tracepoint.c for more details.
5809 Configurations for embedded MIPS now include a simulator contributed
5810 by Cygnus Solutions. The simulator supports the instruction sets
5811 of most MIPS variants.
5815 Sparc configurations may now include the ERC32 simulator contributed
5816 by the European Space Agency. The simulator is not built into
5817 Sparc targets by default; configure with --enable-sim to include it.
5821 For target configurations that may include multiple variants of a
5822 basic architecture (such as MIPS and SH), you may now set the
5823 architecture explicitly. "set arch" sets, "info arch" lists
5824 the possible architectures.
5826 *** Changes in GDB-4.16:
5828 * New native configurations
5830 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5831 M68K NetBSD m68k-*-netbsd*
5832 PowerPC AIX 4.x powerpc-*-aix*
5833 PowerPC MacOS powerpc-*-macos*
5834 PowerPC Windows NT powerpcle-*-cygwin32
5835 RS/6000 AIX 4.x rs6000-*-aix4*
5839 ARM with RDP protocol arm-*-*
5840 I960 with MON960 i960-*-coff
5841 MIPS VxWorks mips*-*-vxworks*
5842 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5843 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5845 Matra Sparclet sparclet-*-*
5849 The powerpc-eabi configuration now includes the PSIM simulator,
5850 contributed by Andrew Cagney, with assistance from Mike Meissner.
5851 PSIM is a very elaborate model of the PowerPC, including not only
5852 basic instruction set execution, but also details of execution unit
5853 performance and I/O hardware. See sim/ppc/README for more details.
5857 GDB now works with Solaris 2.5.
5859 * Windows 95/NT native
5861 GDB will now work as a native debugger on Windows 95 and Windows NT.
5862 To build it from source, you must use the "gnu-win32" environment,
5863 which uses a DLL to emulate enough of Unix to run the GNU tools.
5864 Further information, binaries, and sources are available at
5865 ftp.cygnus.com, under pub/gnu-win32.
5867 * dont-repeat command
5869 If a user-defined command includes the command `dont-repeat', then the
5870 command will not be repeated if the user just types return. This is
5871 useful if the command is time-consuming to run, so that accidental
5872 extra keystrokes don't run the same command many times.
5874 * Send break instead of ^C
5876 The standard remote protocol now includes an option to send a break
5877 rather than a ^C to the target in order to interrupt it. By default,
5878 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5880 * Remote protocol timeout
5882 The standard remote protocol includes a new variable `remotetimeout'
5883 that allows you to set the number of seconds before GDB gives up trying
5884 to read from the target. The default value is 2.
5886 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5888 By default GDB will automatically keep track of objects as they are
5889 loaded and unloaded by the dynamic linker. By using the command `set
5890 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5891 when shared library events occur, thus allowing you to set breakpoints
5892 in shared libraries which are explicitly loaded by the inferior.
5894 Note this feature does not work on hpux8. On hpux9 you must link
5895 /usr/lib/end.o into your program. This feature should work
5896 automatically on hpux10.
5898 * Irix 5.x hardware watchpoint support
5900 Irix 5 configurations now support the use of hardware watchpoints.
5902 * Mips protocol "SYN garbage limit"
5904 When debugging a Mips target using the `target mips' protocol, you
5905 may set the number of characters that GDB will ignore by setting
5906 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5907 every character. The default value is 1050.
5909 * Recording and replaying remote debug sessions
5911 If you set `remotelogfile' to the name of a file, gdb will write to it
5912 a recording of a remote debug session. This recording may then be
5913 replayed back to gdb using "gdbreplay". See gdbserver/README for
5914 details. This is useful when you have a problem with GDB while doing
5915 remote debugging; you can make a recording of the session and send it
5916 to someone else, who can then recreate the problem.
5918 * Speedups for remote debugging
5920 GDB includes speedups for downloading and stepping MIPS systems using
5921 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5922 and more efficient S-record downloading.
5924 * Memory use reductions and statistics collection
5926 GDB now uses less memory and reports statistics about memory usage.
5927 Try the `maint print statistics' command, for example.
5929 *** Changes in GDB-4.15:
5931 * Psymtabs for XCOFF
5933 The symbol reader for AIX GDB now uses partial symbol tables. This
5934 can greatly improve startup time, especially for large executables.
5936 * Remote targets use caching
5938 Remote targets now use a data cache to speed up communication with the
5939 remote side. The data cache could lead to incorrect results because
5940 it doesn't know about volatile variables, thus making it impossible to
5941 debug targets which use memory mapped I/O devices. `set remotecache
5942 off' turns the the data cache off.
5944 * Remote targets may have threads
5946 The standard remote protocol now includes support for multiple threads
5947 in the target system, using new protocol commands 'H' and 'T'. See
5948 gdb/remote.c for details.
5952 If GDB is configured with `--enable-netrom', then it will include
5953 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5954 acts as though it is a bank of ROM on the target board, but you can
5955 write into it over the network. GDB's support consists only of
5956 support for fast loading into the emulated ROM; to debug, you must use
5957 another protocol, such as standard remote protocol. The usual
5958 sequence is something like
5960 target nrom <netrom-hostname>
5962 target remote <netrom-hostname>:1235
5966 GDB now includes support for the Apple Macintosh, as a host only. It
5967 may be run as either an MPW tool or as a standalone application, and
5968 it can debug through the serial port. All the usual GDB commands are
5969 available, but to the target command, you must supply "serial" as the
5970 device type instead of "/dev/ttyXX". See mpw-README in the main
5971 directory for more information on how to build. The MPW configuration
5972 scripts */mpw-config.in support only a few targets, and only the
5973 mips-idt-ecoff target has been tested.
5977 GDB configuration now uses autoconf. This is not user-visible,
5978 but does simplify configuration and building.
5982 GDB now supports hpux10.
5984 *** Changes in GDB-4.14:
5986 * New native configurations
5988 x86 FreeBSD i[345]86-*-freebsd
5989 x86 NetBSD i[345]86-*-netbsd
5990 NS32k NetBSD ns32k-*-netbsd
5991 Sparc NetBSD sparc-*-netbsd
5995 A29K VxWorks a29k-*-vxworks
5996 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5997 CPU32 EST-300 emulator m68*-*-est*
5998 PowerPC ELF powerpc-*-elf
6001 * Alpha OSF/1 support for procfs
6003 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6004 possible to attach to running processes. As the mounting of the /proc
6005 filesystem is optional on the Alpha, GDB automatically determines
6006 the availability of /proc during startup. This can lead to problems
6007 if /proc is unmounted after GDB has been started.
6009 * Arguments to user-defined commands
6011 User commands may accept up to 10 arguments separated by whitespace.
6012 Arguments are accessed within the user command via $arg0..$arg9. A
6015 print $arg0 + $arg1 + $arg2
6017 To execute the command use:
6020 Defines the command "adder" which prints the sum of its three arguments.
6021 Note the arguments are text substitutions, so they may reference variables,
6022 use complex expressions, or even perform inferior function calls.
6024 * New `if' and `while' commands
6026 This makes it possible to write more sophisticated user-defined
6027 commands. Both commands take a single argument, which is the
6028 expression to evaluate, and must be followed by the commands to
6029 execute, one per line, if the expression is nonzero, the list being
6030 terminated by the word `end'. The `if' command list may include an
6031 `else' word, which causes the following commands to be executed only
6032 if the expression is zero.
6034 * Fortran source language mode
6036 GDB now includes partial support for Fortran 77. It will recognize
6037 Fortran programs and can evaluate a subset of Fortran expressions, but
6038 variables and functions may not be handled correctly. GDB will work
6039 with G77, but does not yet know much about symbols emitted by other
6042 * Better HPUX support
6044 Most debugging facilities now work on dynamic executables for HPPAs
6045 running hpux9 or later. You can attach to running dynamically linked
6046 processes, but by default the dynamic libraries will be read-only, so
6047 for instance you won't be able to put breakpoints in them. To change
6048 that behavior do the following before running the program:
6054 This will cause the libraries to be mapped private and read-write.
6055 To revert to the normal behavior, do this:
6061 You cannot set breakpoints or examine data in the library until after
6062 the library is loaded if the function/data symbols do not have
6065 GDB can now also read debug symbols produced by the HP C compiler on
6066 HPPAs (sorry, no C++, Fortran or 68k support).
6068 * Target byte order now dynamically selectable
6070 You can choose which byte order to use with a target system, via the
6071 commands "set endian big" and "set endian little", and you can see the
6072 current setting by using "show endian". You can also give the command
6073 "set endian auto", in which case GDB will use the byte order
6074 associated with the executable. Currently, only embedded MIPS
6075 configurations support dynamic selection of target byte order.
6077 * New DOS host serial code
6079 This version uses DPMI interrupts to handle buffered I/O, so you
6080 no longer need to run asynctsr when debugging boards connected to
6083 *** Changes in GDB-4.13:
6085 * New "complete" command
6087 This lists all the possible completions for the rest of the line, if it
6088 were to be given as a command itself. This is intended for use by emacs.
6090 * Trailing space optional in prompt
6092 "set prompt" no longer adds a space for you after the prompt you set. This
6093 allows you to set a prompt which ends in a space or one that does not.
6095 * Breakpoint hit counts
6097 "info break" now displays a count of the number of times the breakpoint
6098 has been hit. This is especially useful in conjunction with "ignore"; you
6099 can ignore a large number of breakpoint hits, look at the breakpoint info
6100 to see how many times the breakpoint was hit, then run again, ignoring one
6101 less than that number, and this will get you quickly to the last hit of
6104 * Ability to stop printing at NULL character
6106 "set print null-stop" will cause GDB to stop printing the characters of
6107 an array when the first NULL is encountered. This is useful when large
6108 arrays actually contain only short strings.
6110 * Shared library breakpoints
6112 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6113 breakpoints in shared libraries before the executable is run.
6115 * Hardware watchpoints
6117 There is a new hardware breakpoint for the watch command for sparclite
6118 targets. See gdb/sparclite/hw_breakpoint.note.
6120 Hardware watchpoints are also now supported under GNU/Linux.
6124 Annotations have been added. These are for use with graphical interfaces,
6125 and are still experimental. Currently only gdba.el uses these.
6127 * Improved Irix 5 support
6129 GDB now works properly with Irix 5.2.
6131 * Improved HPPA support
6133 GDB now works properly with the latest GCC and GAS.
6135 * New native configurations
6137 Sequent PTX4 i[34]86-sequent-ptx4
6138 HPPA running OSF/1 hppa*-*-osf*
6139 Atari TT running SVR4 m68*-*-sysv4*
6140 RS/6000 LynxOS rs6000-*-lynxos*
6144 OS/9000 i[34]86-*-os9k
6145 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6148 * Hitachi SH7000 and E7000-PC ICE support
6150 There is now support for communicating with the Hitachi E7000-PC ICE.
6151 This is available automatically when GDB is configured for the SH.
6155 As usual, a variety of small fixes and improvements, both generic
6156 and configuration-specific. See the ChangeLog for more detail.
6158 *** Changes in GDB-4.12:
6160 * Irix 5 is now supported
6164 GDB-4.12 on the HPPA has a number of changes which make it unable
6165 to debug the output from the currently released versions of GCC and
6166 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6167 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6168 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6171 *** Changes in GDB-4.11:
6173 * User visible changes:
6177 The "set remotedebug" option is now consistent between the mips remote
6178 target, remote targets using the gdb-specific protocol, UDI (AMD's
6179 debug protocol for the 29k) and the 88k bug monitor. It is now an
6180 integer specifying a debug level (normally 0 or 1, but 2 means more
6181 debugging info for the mips target).
6183 * DEC Alpha native support
6185 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6186 debug info, but GDB works fairly well with the DEC compiler and should
6187 work with a future GCC release. See the README file for a few
6188 Alpha-specific notes.
6190 * Preliminary thread implementation
6192 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6194 * LynxOS native and target support for 386
6196 This release has been hosted on LynxOS 2.2, and also can be configured
6197 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6200 * Improvements in C++ mangling/demangling.
6202 This release has much better g++ debugging, specifically in name
6203 mangling/demangling, virtual function calls, print virtual table,
6204 call methods, ...etc.
6206 *** Changes in GDB-4.10:
6208 * User visible changes:
6210 Remote debugging using the GDB-specific (`target remote') protocol now
6211 supports the `load' command. This is only useful if you have some
6212 other way of getting the stub to the target system, and you can put it
6213 somewhere in memory where it won't get clobbered by the download.
6215 Filename completion now works.
6217 When run under emacs mode, the "info line" command now causes the
6218 arrow to point to the line specified. Also, "info line" prints
6219 addresses in symbolic form (as well as hex).
6221 All vxworks based targets now support a user settable option, called
6222 vxworks-timeout. This option represents the number of seconds gdb
6223 should wait for responses to rpc's. You might want to use this if
6224 your vxworks target is, perhaps, a slow software simulator or happens
6225 to be on the far side of a thin network line.
6229 This release contains support for using a DEC alpha as a GDB host for
6230 cross debugging. Native alpha debugging is not supported yet.
6233 *** Changes in GDB-4.9:
6237 This is the first GDB release which is accompanied by a matching testsuite.
6238 The testsuite requires installation of dejagnu, which should be available
6239 via ftp from most sites that carry GNU software.
6243 'Cfront' style demangling has had its name changed to 'ARM' style, to
6244 emphasize that it was written from the specifications in the C++ Annotated
6245 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6246 disclaimers, it still generated too much confusion with users attempting to
6247 use gdb with AT&T cfront.
6251 GDB now uses a standard remote interface to a simulator library.
6252 So far, the library contains simulators for the Zilog Z8001/2, the
6253 Hitachi H8/300, H8/500 and Super-H.
6255 * New targets supported
6257 H8/300 simulator h8300-hitachi-hms or h8300hms
6258 H8/500 simulator h8500-hitachi-hms or h8500hms
6259 SH simulator sh-hitachi-hms or sh
6260 Z8000 simulator z8k-zilog-none or z8ksim
6261 IDT MIPS board over serial line mips-idt-ecoff
6263 Cross-debugging to GO32 targets is supported. It requires a custom
6264 version of the i386-stub.c module which is integrated with the
6265 GO32 memory extender.
6267 * New remote protocols
6269 MIPS remote debugging protocol.
6271 * New source languages supported
6273 This version includes preliminary support for Chill, a Pascal like language
6274 used by telecommunications companies. Chill support is also being integrated
6275 into the GNU compiler, but we don't know when it will be publically available.
6278 *** Changes in GDB-4.8:
6280 * HP Precision Architecture supported
6282 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6283 version of this support was available as a set of patches from the
6284 University of Utah. GDB does not support debugging of programs
6285 compiled with the HP compiler, because HP will not document their file
6286 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6287 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6289 Many problems in the preliminary version have been fixed.
6291 * Faster and better demangling
6293 We have improved template demangling and fixed numerous bugs in the GNU style
6294 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6295 character types (wchar_t) are now supported. Demangling of each symbol is now
6296 only done once, and is cached when the symbol table for a file is read in.
6297 This results in a small increase in memory usage for C programs, a moderate
6298 increase in memory usage for C++ programs, and a fantastic speedup in
6301 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6302 from the specifications in the Annotated Reference Manual, which AT&T's
6303 compiler does not actually implement.
6305 * G++ multiple inheritance compiler problem
6307 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6308 inheritance lattices was reworked to properly discover ambiguities. We
6309 recently found an example which causes this new algorithm to fail in a
6310 very subtle way, producing bad debug information for those classes.
6311 The file 'gcc.patch' (in this directory) can be applied to gcc to
6312 circumvent the problem. A future GCC release will contain a complete
6315 The previous G++ debug info problem (mentioned below for the gdb-4.7
6316 release) is fixed in gcc version 2.3.2.
6318 * Improved configure script
6320 The `configure' script will now attempt to guess your system type if
6321 you don't supply a host system type. The old scheme of supplying a
6322 host system triplet is preferable over using this. All the magic is
6323 done in the new `config.guess' script. Examine it for details.
6325 We have also brought our configure script much more in line with the FSF's
6326 version. It now supports the --with-xxx options. In particular,
6327 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6328 The resulting GDB will not be able to read arbitrary object file formats --
6329 only the format ``expected'' to be used on the configured target system.
6330 We hope to make this the default in a future release.
6332 * Documentation improvements
6334 There's new internal documentation on how to modify GDB, and how to
6335 produce clean changes to the code. We implore people to read it
6336 before submitting changes.
6338 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6339 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6340 `info' files are also provided. To build `info' files from scratch,
6341 you will need the latest `makeinfo' release, which will be available in
6342 a future texinfo-X.Y release.
6344 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6345 We're not sure exactly which versions have this problem, but it has
6346 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6347 or better. If that isn't possible, there is a patch in
6348 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6349 around this problem.
6353 GDB now supports array constants that can be used in expressions typed in by
6354 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6355 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6358 The new directory `gdb/sparclite' contains a program that demonstrates
6359 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6361 * New native hosts supported
6363 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6364 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6366 * New targets supported
6368 AMD 29k family via UDI a29k-amd-udi or udi29k
6370 * New file formats supported
6372 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6373 HPUX core files, and SCO 3.2v2 core files.
6377 Attaching to processes now works again; thanks for the many bug reports.
6379 We have also stomped on a bunch of core dumps caused by
6380 printf_filtered("%s") problems.
6382 We eliminated a copyright problem on the rpc and ptrace header files
6383 for VxWorks, which was discovered at the last minute during the 4.7
6384 release. You should now be able to build a VxWorks GDB.
6386 You can now interrupt gdb while an attached process is running. This
6387 will cause the attached process to stop, and give control back to GDB.
6389 We fixed problems caused by using too many file descriptors
6390 for reading symbols from object files and libraries. This was
6391 especially a problem for programs that used many (~100) shared
6394 The `step' command now only enters a subroutine if there is line number
6395 information for the subroutine. Otherwise it acts like the `next'
6396 command. Previously, `step' would enter subroutines if there was
6397 any debugging information about the routine. This avoids problems
6398 when using `cc -g1' on MIPS machines.
6400 * Internal improvements
6402 GDB's internal interfaces have been improved to make it easier to support
6403 debugging of multiple languages in the future.
6405 GDB now uses a common structure for symbol information internally.
6406 Minimal symbols (derived from linkage symbols in object files), partial
6407 symbols (from a quick scan of debug information), and full symbols
6408 contain a common subset of information, making it easier to write
6409 shared code that handles any of them.
6411 * New command line options
6413 We now accept --silent as an alias for --quiet.
6417 The memory-mapped-malloc library is now licensed under the GNU Library
6418 General Public License.
6420 *** Changes in GDB-4.7:
6422 * Host/native/target split
6424 GDB has had some major internal surgery to untangle the support for
6425 hosts and remote targets. Now, when you configure GDB for a remote
6426 target, it will no longer load in all of the support for debugging
6427 local programs on the host. When fully completed and tested, this will
6428 ensure that arbitrary host/target combinations are possible.
6430 The primary conceptual shift is to separate the non-portable code in
6431 GDB into three categories. Host specific code is required any time GDB
6432 is compiled on that host, regardless of the target. Target specific
6433 code relates to the peculiarities of the target, but can be compiled on
6434 any host. Native specific code is everything else: it can only be
6435 built when the host and target are the same system. Child process
6436 handling and core file support are two common `native' examples.
6438 GDB's use of /proc for controlling Unix child processes is now cleaner.
6439 It has been split out into a single module under the `target_ops' vector,
6440 plus two native-dependent functions for each system that uses /proc.
6442 * New hosts supported
6444 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6445 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6446 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6448 * New targets supported
6450 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6451 68030 and CPU32 m68030-*-*, m68332-*-*
6453 * New native hosts supported
6455 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6456 (386bsd is not well tested yet)
6457 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6459 * New file formats supported
6461 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6462 supports reading of `a.out.adobe' object files, which are an a.out
6463 format extended with minimal information about multiple sections.
6467 `show copying' is the same as the old `info copying'.
6468 `show warranty' is the same as `info warrantee'.
6469 These were renamed for consistency. The old commands continue to work.
6471 `info handle' is a new alias for `info signals'.
6473 You can now define pre-command hooks, which attach arbitrary command
6474 scripts to any command. The commands in the hook will be executed
6475 prior to the user's command. You can also create a hook which will be
6476 executed whenever the program stops. See gdb.texinfo.
6480 We now deal with Cfront style name mangling, and can even extract type
6481 info from mangled symbols. GDB can automatically figure out which
6482 symbol mangling style your C++ compiler uses.
6484 Calling of methods and virtual functions has been improved as well.
6488 The crash that occured when debugging Sun Ansi-C compiled binaries is
6489 fixed. This was due to mishandling of the extra N_SO stabs output
6492 We also finally got Ultrix 4.2 running in house, and fixed core file
6493 support, with help from a dozen people on the net.
6495 John M. Farrell discovered that the reason that single-stepping was so
6496 slow on all of the Mips based platforms (primarily SGI and DEC) was
6497 that we were trying to demangle and lookup a symbol used for internal
6498 purposes on every instruction that was being stepped through. Changing
6499 the name of that symbol so that it couldn't be mistaken for a C++
6500 mangled symbol sped things up a great deal.
6502 Rich Pixley sped up symbol lookups in general by getting much smarter
6503 about when C++ symbol mangling is necessary. This should make symbol
6504 completion (TAB on the command line) much faster. It's not as fast as
6505 we'd like, but it's significantly faster than gdb-4.6.
6509 A new user controllable variable 'call_scratch_address' can
6510 specify the location of a scratch area to be used when GDB
6511 calls a function in the target. This is necessary because the
6512 usual method of putting the scratch area on the stack does not work
6513 in systems that have separate instruction and data spaces.
6515 We integrated changes to support the 29k UDI (Universal Debugger
6516 Interface), but discovered at the last minute that we didn't have all
6517 of the appropriate copyright paperwork. We are working with AMD to
6518 resolve this, and hope to have it available soon.
6522 We have sped up the remote serial line protocol, especially for targets
6523 with lots of registers. It now supports a new `expedited status' ('T')
6524 message which can be used in place of the existing 'S' status message.
6525 This allows the remote stub to send only the registers that GDB
6526 needs to make a quick decision about single-stepping or conditional
6527 breakpoints, eliminating the need to fetch the entire register set for
6528 each instruction being stepped through.
6530 The GDB remote serial protocol now implements a write-through cache for
6531 registers, only re-reading the registers if the target has run.
6533 There is also a new remote serial stub for SPARC processors. You can
6534 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6535 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6536 processor with a serial port.
6540 Configure.in files have become much easier to read and modify. A new
6541 `table driven' format makes it more obvious what configurations are
6542 supported, and what files each one uses.
6546 There is a new opcodes library which will eventually contain all of the
6547 disassembly routines and opcode tables. At present, it only contains
6548 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6549 disassembler (binutils/objdump) to share these routines.
6551 The libiberty library is now copylefted under the GNU Library General
6552 Public License. This allows more liberal use, and was done so libg++
6553 can use it. This makes no difference to GDB, since the Library License
6554 grants all the rights from the General Public License.
6558 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6559 reference to the stabs symbol info used by the debugger. It is (as far
6560 as we know) the only published document on this fascinating topic. We
6561 encourage you to read it, compare it to the stabs information on your
6562 system, and send improvements on the document in general (to
6563 bug-gdb@prep.ai.mit.edu).
6565 And, of course, many bugs have been fixed.
6568 *** Changes in GDB-4.6:
6570 * Better support for C++ function names
6572 GDB now accepts as input the "demangled form" of C++ overloaded function
6573 names and member function names, and can do command completion on such names
6574 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6575 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6576 Make use of command completion, it is your friend.
6578 GDB also now accepts a variety of C++ mangled symbol formats. They are
6579 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6580 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6581 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6582 for the list of formats.
6584 * G++ symbol mangling problem
6586 Recent versions of gcc have a bug in how they emit debugging information for
6587 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6588 directory) can be applied to gcc to fix the problem. Alternatively, if you
6589 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6590 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6591 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6594 * New 'maintenance' command
6596 All of the commands related to hacking GDB internals have been moved out of
6597 the main command set, and now live behind the 'maintenance' command. This
6598 can also be abbreviated as 'mt'. The following changes were made:
6600 dump-me -> maintenance dump-me
6601 info all-breakpoints -> maintenance info breakpoints
6602 printmsyms -> maintenance print msyms
6603 printobjfiles -> maintenance print objfiles
6604 printpsyms -> maintenance print psymbols
6605 printsyms -> maintenance print symbols
6607 The following commands are new:
6609 maintenance demangle Call internal GDB demangler routine to
6610 demangle a C++ link name and prints the result.
6611 maintenance print type Print a type chain for a given symbol
6613 * Change to .gdbinit file processing
6615 We now read the $HOME/.gdbinit file before processing the argv arguments
6616 (e.g. reading symbol files or core files). This allows global parameters to
6617 be set, which will apply during the symbol reading. The ./.gdbinit is still
6618 read after argv processing.
6620 * New hosts supported
6622 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6624 GNU/Linux support i386-unknown-linux or linux
6626 We are also including code to support the HP/PA running BSD and HPUX. This
6627 is almost guaranteed not to work, as we didn't have time to test or build it
6628 for this release. We are including it so that the more adventurous (or
6629 masochistic) of you can play with it. We also had major problems with the
6630 fact that the compiler that we got from HP doesn't support the -g option.
6633 * New targets supported
6635 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6637 * More smarts about finding #include files
6639 GDB now remembers the compilation directory for all include files, and for
6640 all files from which C is generated (like yacc and lex sources). This
6641 greatly improves GDB's ability to find yacc/lex sources, and include files,
6642 especially if you are debugging your program from a directory different from
6643 the one that contains your sources.
6645 We also fixed a bug which caused difficulty with listing and setting
6646 breakpoints in include files which contain C code. (In the past, you had to
6647 try twice in order to list an include file that you hadn't looked at before.)
6649 * Interesting infernals change
6651 GDB now deals with arbitrary numbers of sections, where the symbols for each
6652 section must be relocated relative to that section's landing place in the
6653 target's address space. This work was needed to support ELF with embedded
6654 stabs used by Solaris-2.0.
6656 * Bug fixes (of course!)
6658 There have been loads of fixes for the following things:
6659 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6660 i960, stabs, DOS(GO32), procfs, etc...
6662 See the ChangeLog for details.
6664 *** Changes in GDB-4.5:
6666 * New machines supported (host and target)
6668 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6670 SGI Irix-4.x mips-sgi-irix4 or iris4
6672 * New malloc package
6674 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6675 Mmalloc is capable of handling mutiple heaps of memory. It is also
6676 capable of saving a heap to a file, and then mapping it back in later.
6677 This can be used to greatly speedup the startup of GDB by using a
6678 pre-parsed symbol table which lives in a mmalloc managed heap. For
6679 more details, please read mmalloc/mmalloc.texi.
6683 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6684 'help info proc' for details.
6686 * MIPS ecoff symbol table format
6688 The code that reads MIPS symbol table format is now supported on all hosts.
6689 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6692 * File name changes for MS-DOS
6694 Many files in the config directories have been renamed to make it easier to
6695 support GDB on MS-DOSe systems (which have very restrictive file name
6696 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6697 environment) is close to working but has some remaining problems. Note
6698 that debugging of DOS programs is not supported, due to limitations
6699 in the ``operating system'', but it can be used to host cross-debugging.
6701 * Cross byte order fixes
6703 Many fixes have been made to support cross debugging of Sparc and MIPS
6704 targets from hosts whose byte order differs.
6706 * New -mapped and -readnow options
6708 If memory-mapped files are available on your system through the 'mmap'
6709 system call, you can use the -mapped option on the `file' or
6710 `symbol-file' commands to cause GDB to write the symbols from your
6711 program into a reusable file. If the program you are debugging is
6712 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6713 Future GDB debugging sessions will notice the presence of this file,
6714 and will quickly map in symbol information from it, rather than reading
6715 the symbol table from the executable program. Using the '-mapped'
6716 option in a GDB `file' or `symbol-file' command has the same effect as
6717 starting GDB with the '-mapped' command-line option.
6719 You can cause GDB to read the entire symbol table immediately by using
6720 the '-readnow' option with any of the commands that load symbol table
6721 information (or on the GDB command line). This makes the command
6722 slower, but makes future operations faster.
6724 The -mapped and -readnow options are typically combined in order to
6725 build a `fred.syms' file that contains complete symbol information.
6726 A simple GDB invocation to do nothing but build a `.syms' file for future
6729 gdb -batch -nx -mapped -readnow programname
6731 The `.syms' file is specific to the host machine on which GDB is run.
6732 It holds an exact image of GDB's internal symbol table. It cannot be
6733 shared across multiple host platforms.
6735 * longjmp() handling
6737 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6738 siglongjmp() without losing control. This feature has not yet been ported to
6739 all systems. It currently works on many 386 platforms, all MIPS-based
6740 platforms (SGI, DECstation, etc), and Sun3/4.
6744 Preliminary work has been put in to support the new Solaris OS from Sun. At
6745 this time, it can control and debug processes, but it is not capable of
6750 As always, many many bug fixes. The major areas were with g++, and mipsread.
6751 People using the MIPS-based platforms should experience fewer mysterious
6752 crashes and trashed symbol tables.
6754 *** Changes in GDB-4.4:
6756 * New machines supported (host and target)
6758 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6760 BSD Reno on Vax vax-dec-bsd
6761 Ultrix on Vax vax-dec-ultrix
6763 * New machines supported (target)
6765 AMD 29000 embedded, using EBMON a29k-none-none
6769 GDB continues to improve its handling of C++. `References' work better.
6770 The demangler has also been improved, and now deals with symbols mangled as
6771 per the Annotated C++ Reference Guide.
6773 GDB also now handles `stabs' symbol information embedded in MIPS
6774 `ecoff' symbol tables. Since the ecoff format was not easily
6775 extensible to handle new languages such as C++, this appeared to be a
6776 good way to put C++ debugging info into MIPS binaries. This option
6777 will be supported in the GNU C compiler, version 2, when it is
6780 * New features for SVR4
6782 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6783 shared libraries. Debugging dynamically linked programs should present
6784 only minor differences from debugging statically linked programs.
6786 The `info proc' command will print out information about any process
6787 on an SVR4 system (including the one you are debugging). At the moment,
6788 it prints the address mappings of the process.
6790 If you bring up GDB on another SVR4 system, please send mail to
6791 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6793 * Better dynamic linking support in SunOS
6795 Reading symbols from shared libraries which contain debugging symbols
6796 now works properly. However, there remain issues such as automatic
6797 skipping of `transfer vector' code during function calls, which
6798 make it harder to debug code in a shared library, than to debug the
6799 same code linked statically.
6803 GDB is now using the latest `getopt' routines from the FSF. This
6804 version accepts the -- prefix for options with long names. GDB will
6805 continue to accept the old forms (-option and +option) as well.
6806 Various single letter abbreviations for options have been explicity
6807 added to the option table so that they won't get overshadowed in the
6808 future by other options that begin with the same letter.
6812 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6813 Many assorted bugs have been handled. Many more remain to be handled.
6814 See the various ChangeLog files (primarily in gdb and bfd) for details.
6817 *** Changes in GDB-4.3:
6819 * New machines supported (host and target)
6821 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6822 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6823 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6825 * Almost SCO Unix support
6827 We had hoped to support:
6828 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6829 (except for core file support), but we discovered very late in the release
6830 that it has problems with process groups that render gdb unusable. Sorry
6831 about that. I encourage people to fix it and post the fixes.
6833 * Preliminary ELF and DWARF support
6835 GDB can read ELF object files on System V Release 4, and can handle
6836 debugging records for C, in DWARF format, in ELF files. This support
6837 is preliminary. If you bring up GDB on another SVR4 system, please
6838 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6843 GDB now uses the latest `readline' library. One user-visible change
6844 is that two tabs will list possible command completions, which previously
6845 required typing M-? (meta-question mark, or ESC ?).
6849 The `stepi' bug that many of you noticed has been squashed.
6850 Many bugs in C++ have been handled. Many more remain to be handled.
6851 See the various ChangeLog files (primarily in gdb and bfd) for details.
6853 * State of the MIPS world (in case you wondered):
6855 GDB can understand the symbol tables emitted by the compilers
6856 supplied by most vendors of MIPS-based machines, including DEC. These
6857 symbol tables are in a format that essentially nobody else uses.
6859 Some versions of gcc come with an assembler post-processor called
6860 mips-tfile. This program is required if you want to do source-level
6861 debugging of gcc-compiled programs. I believe FSF does not ship
6862 mips-tfile with gcc version 1, but it will eventually come with gcc
6865 Debugging of g++ output remains a problem. g++ version 1.xx does not
6866 really support it at all. (If you're lucky, you should be able to get
6867 line numbers and stack traces to work, but no parameters or local
6868 variables.) With some work it should be possible to improve the
6871 When gcc version 2 is released, you will have somewhat better luck.
6872 However, even then you will get confusing results for inheritance and
6875 We will eventually provide full debugging of g++ output on
6876 DECstations. This will probably involve some kind of stabs-in-ecoff
6877 encapulation, but the details have not been worked out yet.
6880 *** Changes in GDB-4.2:
6882 * Improved configuration
6884 Only one copy of `configure' exists now, and it is not self-modifying.
6885 Porting BFD is simpler.
6889 The `step' and `next' commands now only stop at the first instruction
6890 of a source line. This prevents the multiple stops that used to occur
6891 in switch statements, for-loops, etc. `Step' continues to stop if a
6892 function that has debugging information is called within the line.
6896 Lots of small bugs fixed. More remain.
6898 * New host supported (not target)
6900 Intel 386 PC clone running Mach i386-none-mach
6903 *** Changes in GDB-4.1:
6905 * Multiple source language support
6907 GDB now has internal scaffolding to handle several source languages.
6908 It determines the type of each source file from its filename extension,
6909 and will switch expression parsing and number formatting to match the
6910 language of the function in the currently selected stack frame.
6911 You can also specifically set the language to be used, with
6912 `set language c' or `set language modula-2'.
6916 GDB now has preliminary support for the GNU Modula-2 compiler,
6917 currently under development at the State University of New York at
6918 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6919 continue through the fall of 1991 and into 1992.
6921 Other Modula-2 compilers are currently not supported, and attempting to
6922 debug programs compiled with them will likely result in an error as the
6923 symbol table is read. Feel free to work on it, though!
6925 There are hooks in GDB for strict type checking and range checking,
6926 in the `Modula-2 philosophy', but they do not currently work.
6930 GDB can now write to executable and core files (e.g. patch
6931 a variable's value). You must turn this switch on, specify
6932 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6933 by assigning a new value to a variable. Modifications take
6936 * Automatic SunOS shared library reading
6938 When you run your program, GDB automatically determines where its
6939 shared libraries (if any) have been loaded, and reads their symbols.
6940 The `share' command is no longer needed. This also works when
6941 examining core files.
6945 You can specify the number of lines that the `list' command shows.
6948 * New machines supported (host and target)
6950 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6951 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6952 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6954 * New hosts supported (not targets)
6956 IBM RT/PC: romp-ibm-aix or rtpc
6958 * New targets supported (not hosts)
6960 AMD 29000 embedded with COFF a29k-none-coff
6961 AMD 29000 embedded with a.out a29k-none-aout
6962 Ultracomputer remote kernel debug a29k-nyu-kern
6964 * New remote interfaces
6970 *** Changes in GDB-4.0:
6974 Wide output is wrapped at good places to make the output more readable.
6976 Gdb now supports cross-debugging from a host machine of one type to a
6977 target machine of another type. Communication with the target system
6978 is over serial lines. The ``target'' command handles connecting to the
6979 remote system; the ``load'' command will download a program into the
6980 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6981 also supports debugging of realtime processes running under VxWorks,
6982 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6983 stub on the target system.
6985 New CPUs supported include the AMD 29000 and Intel 960.
6987 GDB now reads object files and symbol tables via a ``binary file''
6988 library, which allows a single copy of GDB to debug programs of multiple
6989 object file types such as a.out and coff.
6991 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6992 refcard.dvi and refcard.ps are available to format it).
6995 * Control-Variable user interface simplified
6997 All variables that control the operation of the debugger can be set
6998 by the ``set'' command, and displayed by the ``show'' command.
7000 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7001 ``Show prompt'' produces the response:
7002 Gdb's prompt is new-gdb=>.
7004 What follows are the NEW set commands. The command ``help set'' will
7005 print a complete list of old and new set commands. ``help set FOO''
7006 will give a longer description of the variable FOO. ``show'' will show
7007 all of the variable descriptions and their current settings.
7009 confirm on/off: Enables warning questions for operations that are
7010 hard to recover from, e.g. rerunning the program while
7011 it is already running. Default is ON.
7013 editing on/off: Enables EMACS style command line editing
7014 of input. Previous lines can be recalled with
7015 control-P, the current line can be edited with control-B,
7016 you can search for commands with control-R, etc.
7019 history filename NAME: NAME is where the gdb command history
7020 will be stored. The default is .gdb_history,
7021 or the value of the environment variable
7024 history size N: The size, in commands, of the command history. The
7025 default is 256, or the value of the environment variable
7028 history save on/off: If this value is set to ON, the history file will
7029 be saved after exiting gdb. If set to OFF, the
7030 file will not be saved. The default is OFF.
7032 history expansion on/off: If this value is set to ON, then csh-like
7033 history expansion will be performed on
7034 command line input. The default is OFF.
7036 radix N: Sets the default radix for input and output. It can be set
7037 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7038 in the current radix, so "set radix 10" is always a no-op.
7040 height N: This integer value is the number of lines on a page. Default
7041 is 24, the current `stty rows'' setting, or the ``li#''
7042 setting from the termcap entry matching the environment
7045 width N: This integer value is the number of characters on a line.
7046 Default is 80, the current `stty cols'' setting, or the ``co#''
7047 setting from the termcap entry matching the environment
7050 Note: ``set screensize'' is obsolete. Use ``set height'' and
7051 ``set width'' instead.
7053 print address on/off: Print memory addresses in various command displays,
7054 such as stack traces and structure values. Gdb looks
7055 more ``symbolic'' if you turn this off; it looks more
7056 ``machine level'' with it on. Default is ON.
7058 print array on/off: Prettyprint arrays. New convenient format! Default
7061 print demangle on/off: Print C++ symbols in "source" form if on,
7064 print asm-demangle on/off: Same, for assembler level printouts
7067 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7070 * Support for Epoch Environment.
7072 The epoch environment is a version of Emacs v18 with windowing. One
7073 new command, ``inspect'', is identical to ``print'', except that if you
7074 are running in the epoch environment, the value is printed in its own
7078 * Support for Shared Libraries
7080 GDB can now debug programs and core files that use SunOS shared libraries.
7081 Symbols from a shared library cannot be referenced
7082 before the shared library has been linked with the program (this
7083 happens after you type ``run'' and before the function main() is entered).
7084 At any time after this linking (including when examining core files
7085 from dynamically linked programs), gdb reads the symbols from each
7086 shared library when you type the ``sharedlibrary'' command.
7087 It can be abbreviated ``share''.
7089 sharedlibrary REGEXP: Load shared object library symbols for files
7090 matching a unix regular expression. No argument
7091 indicates to load symbols for all shared libraries.
7093 info sharedlibrary: Status of loaded shared libraries.
7098 A watchpoint stops execution of a program whenever the value of an
7099 expression changes. Checking for this slows down execution
7100 tremendously whenever you are in the scope of the expression, but is
7101 quite useful for catching tough ``bit-spreader'' or pointer misuse
7102 problems. Some machines such as the 386 have hardware for doing this
7103 more quickly, and future versions of gdb will use this hardware.
7105 watch EXP: Set a watchpoint (breakpoint) for an expression.
7107 info watchpoints: Information about your watchpoints.
7109 delete N: Deletes watchpoint number N (same as breakpoints).
7110 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7111 enable N: Re-enables watchpoint number N (same as breakpoints).
7114 * C++ multiple inheritance
7116 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7119 * C++ exception handling
7121 Gdb now supports limited C++ exception handling. Besides the existing
7122 ability to breakpoint on an exception handler, gdb can breakpoint on
7123 the raising of an exception (before the stack is peeled back to the
7126 catch FOO: If there is a FOO exception handler in the dynamic scope,
7127 set a breakpoint to catch exceptions which may be raised there.
7128 Multiple exceptions (``catch foo bar baz'') may be caught.
7130 info catch: Lists all exceptions which may be caught in the
7131 current stack frame.
7134 * Minor command changes
7136 The command ``call func (arg, arg, ...)'' now acts like the print
7137 command, except it does not print or save a value if the function's result
7138 is void. This is similar to dbx usage.
7140 The ``up'' and ``down'' commands now always print the frame they end up
7141 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7142 frames without printing.
7144 * New directory command
7146 'dir' now adds directories to the FRONT of the source search path.
7147 The path starts off empty. Source files that contain debug information
7148 about the directory in which they were compiled can be found even
7149 with an empty path; Sun CC and GCC include this information. If GDB can't
7150 find your source file in the current directory, type "dir .".
7152 * Configuring GDB for compilation
7154 For normal use, type ``./configure host''. See README or gdb.texinfo
7157 GDB now handles cross debugging. If you are remotely debugging between
7158 two different machines, type ``./configure host -target=targ''.
7159 Host is the machine where GDB will run; targ is the machine
7160 where the program that you are debugging will run.