1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
8 * GDB and GDBserver now support access to additional registers on
9 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
12 * GDB now has experimental support for the compilation and injection of
13 C++ source code into the inferior. This beta release does not include
14 support for several language features, such as templates, constructors,
17 This feature requires GCC 7.1 or higher built with libcp1.so
20 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
21 can be passed using the '[ADDRESS]:PORT' notation, or the regular
22 'ADDRESS:PORT' method.
24 * DWARF index cache: GDB can now automatically save indices of DWARF
25 symbols on disk to speed up further loading of the same binaries.
27 * Ada task switching is now supported on aarch64-elf targets when
28 debugging a program using the Ravenscar Profile. For more information,
29 see the "Tasking Support when using the Ravenscar Profile" section
30 in the GDB user manual.
32 * GDB in batch mode now exits with status 1 if the last command to be
35 * The RISC-V target now supports target descriptions.
37 * System call catchpoints now support system call aliases on FreeBSD.
38 When the ABI of a system call changes in FreeBSD, this is
39 implemented by leaving a compatibility system call using the old ABI
40 at the existing number and allocating a new system call number for
41 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
42 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
43 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
44 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
45 so that a system call catchpoint for the 'kevent' system call will
46 catch invocations of both the 'kevent' and 'freebsd11_kevent'
47 binaries. This ensures that 'kevent' system calls are caught for
48 binaries using either the old or new ABIs.
50 * Terminal styling is now available for the CLI and the TUI. GNU
51 Source Highlight can additionally be used to provide styling of
52 source code snippets. See the "set style" commands, below, for more
55 * Removed support for old demangling styles arm, edg, gnu, hp and
61 GNU/Linux/OpenRISC or1k*-*-linux*
65 set debug compile-cplus-types
66 show debug compile-cplus-types
67 Control the display of debug output about type conversion in the
68 C++ compile feature. Commands have no effect while compiliong
73 Control whether debug output about files/functions skipping is
76 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
77 Apply a command to some frames.
78 FLAG arguments allow to control what output to produce and how to handle
79 errors raised when applying COMMAND to a frame.
82 Apply a command to all threads (ignoring errors and empty output).
83 Shortcut for 'thread apply all -s COMMAND'.
86 Apply a command to all frames (ignoring errors and empty output).
87 Shortcut for 'frame apply all -s COMMAND'.
90 Apply a command to all frames of all threads (ignoring errors and empty
92 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
94 maint set dwarf unwinders (on|off)
95 maint show dwarf unwinders
96 Control whether DWARF unwinders can be used.
99 Display a list of open files for a process.
103 Changes to the "frame", "select-frame", and "info frame" CLI commands.
104 These commands all now take a frame specification which
105 is either a frame level, or one of the keywords 'level', 'address',
106 'function', or 'view' followed by a parameter. Selecting a frame by
107 address, or viewing a frame outside the current backtrace now
108 requires the use of a keyword. Selecting a frame by level is
109 unchanged. The MI comment "-stack-select-frame" is unchanged.
111 target remote FILENAME
112 target extended-remote FILENAME
113 If FILENAME is a Unix domain socket, GDB will attempt to connect
114 to this socket instead of opening FILENAME as a character device.
116 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
117 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
118 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
119 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
120 These commands can now print only the searched entities
121 matching the provided regexp(s), giving a condition
122 on the entity names or entity types. The flag -q disables
123 printing headers or informations messages.
129 These commands now determine the syntax for the shown entities
130 according to the language chosen by `set language'. In particular,
131 `set language auto' means to automatically choose the language of
134 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
135 The 'thread apply' command accepts new FLAG arguments.
136 FLAG arguments allow to control what output to produce and how to handle
137 errors raised when applying COMMAND to a thread.
139 set tui tab-width NCHARS
140 show tui tab-width NCHARS
141 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
143 set style enabled [on|off]
145 Enable or disable terminal styling. Styling is enabled by default
146 on most hosts, but disabled by default when in batch mode.
148 set style filename foreground COLOR
149 set style filename background COLOR
150 set style filename intensity VALUE
151 Control the styling of file names.
153 set style function foreground COLOR
154 set style function background COLOR
155 set style function intensity VALUE
156 Control the styling of function names.
158 set style variable foreground COLOR
159 set style variable background COLOR
160 set style variable intensity VALUE
161 Control the styling of variable names.
163 set style address foreground COLOR
164 set style address background COLOR
165 set style address intensity VALUE
166 Control the styling of addresses.
170 ** The '-data-disassemble' MI command now accepts an '-a' option to
171 disassemble the whole function surrounding the given program
172 counter value or function name. Support for this feature can be
173 verified by using the "-list-features" command, which should
174 contain "data-disassemble-a-option".
176 ** Command responses and notifications that include a frame now include
177 the frame's architecture in a new "arch" attribute.
179 * New native configurations
181 GNU/Linux/RISC-V riscv*-*-linux*
182 FreeBSD/riscv riscv*-*-freebsd*
186 GNU/Linux/RISC-V riscv*-*-linux*
188 CSKY GNU/LINUX csky*-*-linux
189 FreeBSD/riscv riscv*-*-freebsd*
193 ** GDB no longer supports Python versions less than 2.6.
195 ** The gdb.Inferior type has a new 'progspace' property, which is the program
196 space associated to that inferior.
198 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
199 of objfiles associated to that program space.
201 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
202 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
205 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
206 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
207 correct and did not work properly.
209 ** The gdb.Value type has a new constructor, which is used to construct a
210 gdb.Value from a Python buffer object and a gdb.Type.
216 Enable or disable the undefined behavior sanitizer. This is
217 disabled by default, but passing --enable-ubsan=yes or
218 --enable-ubsan=auto to configure will enable it. Enabling this can
219 cause a performance penalty. The undefined behavior sanitizer was
220 first introduced in GCC 4.9.
222 *** Changes in GDB 8.2
224 * The 'set disassembler-options' command now supports specifying options
227 * The 'symbol-file' command now accepts an '-o' option to add a relative
228 offset to all sections.
230 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
231 a relative offset to all sections, but it allows to override the load
232 address of individual sections using '-s'.
234 * The 'add-symbol-file' command no longer requires the second argument
235 (address of the text section).
237 * The endianness used with the 'set endian auto' mode in the absence of
238 an executable selected for debugging is now the last endianness chosen
239 either by one of the 'set endian big' and 'set endian little' commands
240 or by inferring from the last executable used, rather than the startup
243 * The pager now allows a "c" response, meaning to disable the pager
244 for the rest of the current command.
246 * The commands 'info variables/functions/types' now show the source line
247 numbers of symbol definitions when available.
249 * 'info proc' now works on running processes on FreeBSD systems and core
250 files created on FreeBSD systems.
252 * C expressions can now use _Alignof, and C++ expressions can now use
255 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
256 the vector length while the process is running.
262 Control display of debugging info regarding the FreeBSD native target.
264 set|show varsize-limit
265 This new setting allows the user to control the maximum size of Ada
266 objects being printed when those objects have a variable type,
267 instead of that maximum size being hardcoded to 65536 bytes.
269 set|show record btrace cpu
270 Controls the processor to be used for enabling errata workarounds for
273 maint check libthread-db
274 Run integrity checks on the current inferior's thread debugging
277 maint set check-libthread-db (on|off)
278 maint show check-libthread-db
279 Control whether to run integrity checks on inferior specific thread
280 debugging libraries as they are loaded. The default is not to
285 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
287 ** The commands attached to a breakpoint can be set by assigning to
288 the breakpoint's "commands" field.
290 ** gdb.execute can now execute multi-line gdb commands.
292 ** The new functions gdb.convenience_variable and
293 gdb.set_convenience_variable can be used to get and set the value
294 of convenience variables.
296 ** A gdb.Parameter will no longer print the "set" help text on an
297 ordinary "set"; instead by default a "set" will be silent unless
298 the get_set_string method returns a non-empty string.
302 RiscV ELF riscv*-*-elf
304 * Removed targets and native configurations
306 m88k running OpenBSD m88*-*-openbsd*
307 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
308 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
309 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
311 * Aarch64/Linux hardware watchpoints improvements
313 Hardware watchpoints on unaligned addresses are now properly
314 supported when running Linux kernel 4.10 or higher: read and access
315 watchpoints are no longer spuriously missed, and all watchpoints
316 lengths between 1 and 8 bytes are supported. On older kernels,
317 watchpoints set on unaligned addresses are no longer missed, with
318 the tradeoff that there is a possibility of false hits being
323 --enable-codesign=CERT
324 This can be used to invoke "codesign -s CERT" after building gdb.
325 This option is useful on macOS, where code signing is required for
326 gdb to work properly.
328 --disable-gdbcli has been removed
329 This is now silently accepted, but does nothing.
331 *** Changes in GDB 8.1
333 * GDB now supports dynamically creating arbitrary register groups specified
334 in XML target descriptions. This allows for finer grain grouping of
335 registers on systems with a large amount of registers.
337 * The 'ptype' command now accepts a '/o' flag, which prints the
338 offsets and sizes of fields in a struct, like the pahole(1) tool.
340 * New "--readnever" command line option instructs GDB to not read each
341 symbol file's symbolic debug information. This makes startup faster
342 but at the expense of not being able to perform symbolic debugging.
343 This option is intended for use cases where symbolic debugging will
344 not be used, e.g., when you only need to dump the debuggee's core.
346 * GDB now uses the GNU MPFR library, if available, to emulate target
347 floating-point arithmetic during expression evaluation when the target
348 uses different floating-point formats than the host. At least version
349 3.1 of GNU MPFR is required.
351 * GDB now supports access to the guarded-storage-control registers and the
352 software-based guarded-storage broadcast control registers on IBM z14.
354 * On Unix systems, GDB now supports transmitting environment variables
355 that are to be set or unset to GDBserver. These variables will
356 affect the environment to be passed to the remote inferior.
358 To inform GDB of environment variables that are to be transmitted to
359 GDBserver, use the "set environment" command. Only user set
360 environment variables are sent to GDBserver.
362 To inform GDB of environment variables that are to be unset before
363 the remote inferior is started by the GDBserver, use the "unset
364 environment" command.
366 * Completion improvements
368 ** GDB can now complete function parameters in linespecs and
369 explicit locations without quoting. When setting breakpoints,
370 quoting around functions names to help with TAB-completion is
371 generally no longer necessary. For example, this now completes
374 (gdb) b function(in[TAB]
375 (gdb) b function(int)
377 Related, GDB is no longer confused with completing functions in
378 C++ anonymous namespaces:
381 (gdb) b (anonymous namespace)::[TAB][TAB]
382 (anonymous namespace)::a_function()
383 (anonymous namespace)::b_function()
385 ** GDB now has much improved linespec and explicit locations TAB
386 completion support, that better understands what you're
387 completing and offers better suggestions. For example, GDB no
388 longer offers data symbols as possible completions when you're
389 setting a breakpoint.
391 ** GDB now TAB-completes label symbol names.
393 ** The "complete" command now mimics TAB completion accurately.
395 * New command line options (gcore)
398 Dump all memory mappings.
400 * Breakpoints on C++ functions are now set on all scopes by default
402 By default, breakpoints on functions/methods are now interpreted as
403 specifying all functions with the given name ignoring missing
404 leading scopes (namespaces and classes).
406 For example, assuming a C++ program with symbols named:
411 both commands "break func()" and "break B::func()" set a breakpoint
414 You can use the new flag "-qualified" to override this. This makes
415 GDB interpret the specified function name as a complete
416 fully-qualified name instead. For example, using the same C++
417 program, the "break -q B::func" command sets a breakpoint on
418 "B::func", only. A parameter has been added to the Python
419 gdb.Breakpoint constructor to achieve the same result when creating
420 a breakpoint from Python.
422 * Breakpoints on functions marked with C++ ABI tags
424 GDB can now set breakpoints on functions marked with C++ ABI tags
425 (e.g., [abi:cxx11]). See here for a description of ABI tags:
426 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
428 Functions with a C++11 abi tag are demangled/displayed like this:
430 function[abi:cxx11](int)
433 You can now set a breakpoint on such functions simply as if they had
436 (gdb) b function(int)
438 Or if you need to disambiguate between tags, like:
440 (gdb) b function[abi:other_tag](int)
442 Tab completion was adjusted accordingly as well.
446 ** New events gdb.new_inferior, gdb.inferior_deleted, and
447 gdb.new_thread are emitted. See the manual for further
448 description of these.
450 ** A new function, "gdb.rbreak" has been added to the Python API.
451 This function allows the setting of a large number of breakpoints
452 via a regex pattern in Python. See the manual for further details.
454 ** Python breakpoints can now accept explicit locations. See the
455 manual for a further description of this feature.
458 * New features in the GDB remote stub, GDBserver
460 ** GDBserver is now able to start inferior processes with a
461 specified initial working directory.
463 The user can set the desired working directory to be used from
464 GDB using the new "set cwd" command.
466 ** New "--selftest" command line option runs some GDBserver self
467 tests. These self tests are disabled in releases.
469 ** On Unix systems, GDBserver now does globbing expansion and variable
470 substitution in inferior command line arguments.
472 This is done by starting inferiors using a shell, like GDB does.
473 See "set startup-with-shell" in the user manual for how to disable
474 this from GDB when using "target extended-remote". When using
475 "target remote", you can disable the startup with shell by using the
476 new "--no-startup-with-shell" GDBserver command line option.
478 ** On Unix systems, GDBserver now supports receiving environment
479 variables that are to be set or unset from GDB. These variables
480 will affect the environment to be passed to the inferior.
482 * When catching an Ada exception raised with a message, GDB now prints
483 the message in the catchpoint hit notification. In GDB/MI mode, that
484 information is provided as an extra field named "exception-message"
485 in the *stopped notification.
487 * Trait objects can now be inspected When debugging Rust code. This
488 requires compiler support which will appear in Rust 1.24.
492 QEnvironmentHexEncoded
493 Inform GDBserver of an environment variable that is to be passed to
494 the inferior when starting it.
497 Inform GDBserver of an environment variable that is to be unset
498 before starting the remote inferior.
501 Inform GDBserver that the environment should be reset (i.e.,
502 user-set environment variables should be unset).
505 Indicates whether the inferior must be started with a shell or not.
508 Tell GDBserver that the inferior to be started should use a specific
511 * The "maintenance print c-tdesc" command now takes an optional
512 argument which is the file name of XML target description.
514 * The "maintenance selftest" command now takes an optional argument to
515 filter the tests to be run.
517 * The "enable", and "disable" commands now accept a range of
518 breakpoint locations, e.g. "enable 1.3-5".
523 Set and show the current working directory for the inferior.
526 Set and show compilation command used for compiling and injecting code
527 with the 'compile' commands.
529 set debug separate-debug-file
530 show debug separate-debug-file
531 Control the display of debug output about separate debug file search.
533 set dump-excluded-mappings
534 show dump-excluded-mappings
535 Control whether mappings marked with the VM_DONTDUMP flag should be
536 dumped when generating a core file.
539 List the registered selftests.
542 Start the debugged program stopping at the first instruction.
545 Control display of debugging messages related to OpenRISC targets.
547 set|show print type nested-type-limit
548 Set and show the limit of nesting level for nested types that the
549 type printer will show.
551 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
554 * Safer/improved support for debugging with no debug info
556 GDB no longer assumes functions with no debug information return
559 This means that GDB now refuses to call such functions unless you
560 tell it the function's type, by either casting the call to the
561 declared return type, or by casting the function to a function
562 pointer of the right type, and calling that:
564 (gdb) p getenv ("PATH")
565 'getenv' has unknown return type; cast the call to its declared return type
566 (gdb) p (char *) getenv ("PATH")
567 $1 = 0x7fffffffe "/usr/local/bin:/"...
568 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
569 $2 = 0x7fffffffe "/usr/local/bin:/"...
571 Similarly, GDB no longer assumes that global variables with no debug
572 info have type 'int', and refuses to print the variable's value
573 unless you tell it the variable's type:
576 'var' has unknown type; cast it to its declared type
580 * New native configurations
582 FreeBSD/aarch64 aarch64*-*-freebsd*
583 FreeBSD/arm arm*-*-freebsd*
587 FreeBSD/aarch64 aarch64*-*-freebsd*
588 FreeBSD/arm arm*-*-freebsd*
589 OpenRISC ELF or1k*-*-elf
591 * Removed targets and native configurations
593 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
595 *** Changes in GDB 8.0
597 * GDB now supports access to the PKU register on GNU/Linux. The register is
598 added by the Memory Protection Keys for Userspace feature which will be
599 available in future Intel CPUs.
601 * GDB now supports C++11 rvalue references.
605 ** New functions to start, stop and access a running btrace recording.
606 ** Rvalue references are now supported in gdb.Type.
608 * GDB now supports recording and replaying rdrand and rdseed Intel 64
611 * Building GDB and GDBserver now requires a C++11 compiler.
613 For example, GCC 4.8 or later.
615 It is no longer possible to build GDB or GDBserver with a C
616 compiler. The --disable-build-with-cxx configure option has been
619 * Building GDB and GDBserver now requires GNU make >= 3.81.
621 It is no longer supported to build GDB or GDBserver with another
622 implementation of the make program or an earlier version of GNU make.
624 * Native debugging on MS-Windows supports command-line redirection
626 Command-line arguments used for starting programs on MS-Windows can
627 now include redirection symbols supported by native Windows shells,
628 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
629 as "run", "start", and "set args", as well as the corresponding MI
632 * Support for thread names on MS-Windows.
634 GDB now catches and handles the special exception that programs
635 running on MS-Windows use to assign names to threads in the
638 * Support for Java programs compiled with gcj has been removed.
640 * User commands now accept an unlimited number of arguments.
641 Previously, only up to 10 was accepted.
643 * The "eval" command now expands user-defined command arguments.
645 This makes it easier to process a variable number of arguments:
650 eval "print $arg%d", $i
655 * Target descriptions can now describe registers for sparc32 and sparc64.
657 * GDB now supports DWARF version 5 (debug information format).
658 Its .debug_names index is not yet supported.
660 * New native configurations
662 FreeBSD/mips mips*-*-freebsd
666 Synopsys ARC arc*-*-elf32
667 FreeBSD/mips mips*-*-freebsd
669 * Removed targets and native configurations
671 Alpha running FreeBSD alpha*-*-freebsd*
672 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
677 Erases all the flash memory regions reported by the target.
679 maint print arc arc-instruction address
680 Print internal disassembler information about instruction at a given address.
684 set disassembler-options
685 show disassembler-options
686 Controls the passing of target specific information to the disassembler.
687 If it is necessary to specify more than one disassembler option then
688 multiple options can be placed together into a comma separated list.
689 The default value is the empty string. Currently, the only supported
690 targets are ARM, PowerPC and S/390.
695 Erases all the flash memory regions reported by the target. This is
696 equivalent to the CLI command flash-erase.
698 -file-list-shared-libraries
699 List the shared libraries in the program. This is
700 equivalent to the CLI command "info shared".
703 Catchpoints stopping the program when Ada exceptions are
704 handled. This is equivalent to the CLI command "catch handlers".
706 *** Changes in GDB 7.12
708 * GDB and GDBserver now build with a C++ compiler by default.
710 The --enable-build-with-cxx configure option is now enabled by
711 default. One must now explicitly configure with
712 --disable-build-with-cxx in order to build with a C compiler. This
713 option will be removed in a future release.
715 * GDBserver now supports recording btrace without maintaining an active
718 * GDB now supports a negative repeat count in the 'x' command to examine
719 memory backward from the given address. For example:
722 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
723 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
724 (gdb) x/-5i 0x0000000000400580
725 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
726 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
727 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
728 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
729 0x40057b <main(int, char**)+25>:
730 callq 0x400536 <Func1(int, char const*)>
732 * Fortran: Support structures with fields of dynamic types and
733 arrays of dynamic types.
735 * The symbol dumping maintenance commands have new syntax.
736 maint print symbols [-pc address] [--] [filename]
737 maint print symbols [-objfile objfile] [-source source] [--] [filename]
738 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
739 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
740 maint print msymbols [-objfile objfile] [--] [filename]
742 * GDB now supports multibit bitfields and enums in target register
745 * New Python-based convenience function $_as_string(val), which returns
746 the textual representation of a value. This function is especially
747 useful to obtain the text label of an enum value.
749 * Intel MPX bound violation handling.
751 Segmentation faults caused by a Intel MPX boundary violation
752 now display the kind of violation (upper or lower), the memory
753 address accessed and the memory bounds, along with the usual
754 signal received and code location.
758 Program received signal SIGSEGV, Segmentation fault
759 Upper bound violation while accessing address 0x7fffffffc3b3
760 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
761 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
763 * Rust language support.
764 GDB now supports debugging programs written in the Rust programming
765 language. See https://www.rust-lang.org/ for more information about
768 * Support for running interpreters on specified input/output devices
770 GDB now supports a new mechanism that allows frontends to provide
771 fully featured GDB console views, as a better alternative to
772 building such views on top of the "-interpreter-exec console"
773 command. See the new "new-ui" command below. With that command,
774 frontends can now start GDB in the traditional command-line mode
775 running in an embedded terminal emulator widget, and create a
776 separate MI interpreter running on a specified i/o device. In this
777 way, GDB handles line editing, history, tab completion, etc. in the
778 console all by itself, and the GUI uses the separate MI interpreter
779 for its own control and synchronization, invisible to the command
782 * The "catch syscall" command catches groups of related syscalls.
784 The "catch syscall" command now supports catching a group of related
785 syscalls using the 'group:' or 'g:' prefix.
790 skip -gfile file-glob-pattern
791 skip -function function
792 skip -rfunction regular-expression
793 A generalized form of the skip command, with new support for
794 glob-style file names and regular expressions for function names.
795 Additionally, a file spec and a function spec may now be combined.
797 maint info line-table REGEXP
798 Display the contents of GDB's internal line table data struture.
801 Run any GDB unit tests that were compiled in.
804 Start a new user interface instance running INTERP as interpreter,
805 using the TTY file for input/output.
809 ** gdb.Breakpoint objects have a new attribute "pending", which
810 indicates whether the breakpoint is pending.
811 ** Three new breakpoint-related events have been added:
812 gdb.breakpoint_created, gdb.breakpoint_modified, and
813 gdb.breakpoint_deleted.
816 Signal ("set") the given MS-Windows event object. This is used in
817 conjunction with the Windows JIT debugging (AeDebug) support, where
818 the OS suspends a crashing process until a debugger can attach to
819 it. Resuming the crashing process, in order to debug it, is done by
822 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
823 was added in GDBserver, including JIT compiling fast tracepoint's
824 conditional expression bytecode into native code.
826 * Support for various remote target protocols and ROM monitors has
829 target m32rsdi Remote M32R debugging over SDI
830 target mips MIPS remote debugging protocol
831 target pmon PMON ROM monitor
832 target ddb NEC's DDB variant of PMON for Vr4300
833 target rockhopper NEC RockHopper variant of PMON
834 target lsi LSI variant of PMO
836 * Support for tracepoints and fast tracepoints on powerpc-linux,
837 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
838 including JIT compiling fast tracepoint's conditional expression
839 bytecode into native code.
841 * MI async record =record-started now includes the method and format used for
842 recording. For example:
844 =record-started,thread-group="i1",method="btrace",format="bts"
846 * MI async record =thread-selected now includes the frame field. For example:
848 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
852 Andes NDS32 nds32*-*-elf
854 *** Changes in GDB 7.11
856 * GDB now supports debugging kernel-based threads on FreeBSD.
858 * Per-inferior thread numbers
860 Thread numbers are now per inferior instead of global. If you're
861 debugging multiple inferiors, GDB displays thread IDs using a
862 qualified INF_NUM.THR_NUM form. For example:
866 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
867 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
868 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
869 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
871 As consequence, thread numbers as visible in the $_thread
872 convenience variable and in Python's InferiorThread.num attribute
873 are no longer unique between inferiors.
875 GDB now maintains a second thread ID per thread, referred to as the
876 global thread ID, which is the new equivalent of thread numbers in
877 previous releases. See also $_gthread below.
879 For backwards compatibility, MI's thread IDs always refer to global
882 * Commands that accept thread IDs now accept the qualified
883 INF_NUM.THR_NUM form as well. For example:
886 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
889 * In commands that accept a list of thread IDs, you can now refer to
890 all threads of an inferior using a star wildcard. GDB accepts
891 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
892 refer to all threads of the current inferior. For example, "info
895 * You can use "info threads -gid" to display the global thread ID of
898 * The new convenience variable $_gthread holds the global number of
901 * The new convenience variable $_inferior holds the number of the
904 * GDB now displays the ID and name of the thread that hit a breakpoint
905 or received a signal, if your program is multi-threaded. For
908 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
909 Thread 1 "main" received signal SIGINT, Interrupt.
911 * Record btrace now supports non-stop mode.
913 * Support for tracepoints on aarch64-linux was added in GDBserver.
915 * The 'record instruction-history' command now indicates speculative execution
916 when using the Intel Processor Trace recording format.
918 * GDB now allows users to specify explicit locations, bypassing
919 the linespec parser. This feature is also available to GDB/MI
922 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
923 GDB now is able to debug both AArch64 applications and ARM applications
926 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
927 including JIT compiling fast tracepoint's conditional expression bytecode
930 * GDB now supports displaced stepping on AArch64 GNU/Linux.
932 * "info threads", "info inferiors", "info display", "info checkpoints"
933 and "maint info program-spaces" now list the corresponding items in
934 ascending ID order, for consistency with all other "info" commands.
936 * In Ada, the overloads selection menu has been enhanced to display the
937 parameter types and the return types for the matching overloaded subprograms.
941 maint set target-non-stop (on|off|auto)
942 maint show target-non-stop
943 Control whether GDB targets always operate in non-stop mode even if
944 "set non-stop" is "off". The default is "auto", meaning non-stop
945 mode is enabled if supported by the target.
947 maint set bfd-sharing
948 maint show bfd-sharing
949 Control the reuse of bfd objects.
953 Control display of debugging info regarding bfd caching.
957 Control display of debugging info regarding FreeBSD threads.
959 set remote multiprocess-extensions-packet
960 show remote multiprocess-extensions-packet
961 Set/show the use of the remote protocol multiprocess extensions.
963 set remote thread-events
964 show remote thread-events
965 Set/show the use of thread create/exit events.
967 set ada print-signatures on|off
968 show ada print-signatures"
969 Control whether parameter types and return types are displayed in overloads
970 selection menus. It is activaled (@code{on}) by default.
974 Controls the maximum size of memory, in bytes, that GDB will
975 allocate for value contents. Prevents incorrect programs from
976 causing GDB to allocate overly large buffers. Default is 64k.
978 * The "disassemble" command accepts a new modifier: /s.
979 It prints mixed source+disassembly like /m with two differences:
980 - disassembled instructions are now printed in program order, and
981 - and source for all relevant files is now printed.
982 The "/m" option is now considered deprecated: its "source-centric"
983 output hasn't proved useful in practice.
985 * The "record instruction-history" command accepts a new modifier: /s.
986 It behaves exactly like /m and prints mixed source+disassembly.
988 * The "set scheduler-locking" command supports a new mode "replay".
989 It behaves like "off" in record mode and like "on" in replay mode.
991 * Support for various ROM monitors has been removed:
993 target dbug dBUG ROM monitor for Motorola ColdFire
994 target picobug Motorola picobug monitor
995 target dink32 DINK32 ROM monitor for PowerPC
996 target m32r Renesas M32R/D ROM monitor
997 target mon2000 mon2000 ROM monitor
998 target ppcbug PPCBUG ROM monitor for PowerPC
1000 * Support for reading/writing memory and extracting values on architectures
1001 whose memory is addressable in units of any integral multiple of 8 bits.
1004 Allows to break when an Ada exception is handled.
1006 * New remote packets
1009 Indicates that an exec system call was executed.
1011 exec-events feature in qSupported
1012 The qSupported packet allows GDB to request support for exec
1013 events using the new 'gdbfeature' exec-event, and the qSupported
1014 response can contain the corresponding 'stubfeature'. Set and
1015 show commands can be used to display whether these features are enabled.
1018 Equivalent to interrupting with the ^C character, but works in
1021 thread created stop reason (T05 create:...)
1022 Indicates that the thread was just created and is stopped at entry.
1024 thread exit stop reply (w exitcode;tid)
1025 Indicates that the thread has terminated.
1028 Enables/disables thread create and exit event reporting. For
1029 example, this is used in non-stop mode when GDB stops a set of
1030 threads and synchronously waits for the their corresponding stop
1031 replies. Without exit events, if one of the threads exits, GDB
1032 would hang forever not knowing that it should no longer expect a
1033 stop for that same thread.
1036 Indicates that there are no resumed threads left in the target (all
1037 threads are stopped). The remote stub reports support for this stop
1038 reply to GDB's qSupported query.
1041 Enables/disables catching syscalls from the inferior process.
1042 The remote stub reports support for this packet to GDB's qSupported query.
1044 syscall_entry stop reason
1045 Indicates that a syscall was just called.
1047 syscall_return stop reason
1048 Indicates that a syscall just returned.
1050 * Extended-remote exec events
1052 ** GDB now has support for exec events on extended-remote Linux targets.
1053 For such targets with Linux kernels 2.5.46 and later, this enables
1054 follow-exec-mode and exec catchpoints.
1056 set remote exec-event-feature-packet
1057 show remote exec-event-feature-packet
1058 Set/show the use of the remote exec event feature.
1060 * Thread names in remote protocol
1062 The reply to qXfer:threads:read may now include a name attribute for each
1065 * Target remote mode fork and exec events
1067 ** GDB now has support for fork and exec events on target remote mode
1068 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1069 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1070 fork and exec catchpoints.
1072 * Remote syscall events
1074 ** GDB now has support for catch syscall on remote Linux targets,
1075 currently enabled on x86/x86_64 architectures.
1077 set remote catch-syscall-packet
1078 show remote catch-syscall-packet
1079 Set/show the use of the remote catch syscall feature.
1083 ** The -var-set-format command now accepts the zero-hexadecimal
1084 format. It outputs data in hexadecimal format with zero-padding on the
1089 ** gdb.InferiorThread objects have a new attribute "global_num",
1090 which refers to the thread's global thread ID. The existing
1091 "num" attribute now refers to the thread's per-inferior number.
1092 See "Per-inferior thread numbers" above.
1093 ** gdb.InferiorThread objects have a new attribute "inferior", which
1094 is the Inferior object the thread belongs to.
1096 *** Changes in GDB 7.10
1098 * Support for process record-replay and reverse debugging on aarch64*-linux*
1099 targets has been added. GDB now supports recording of A64 instruction set
1100 including advance SIMD instructions.
1102 * Support for Sun's version of the "stabs" debug file format has been removed.
1104 * GDB now honors the content of the file /proc/PID/coredump_filter
1105 (PID is the process ID) on GNU/Linux systems. This file can be used
1106 to specify the types of memory mappings that will be included in a
1107 corefile. For more information, please refer to the manual page of
1108 "core(5)". GDB also has a new command: "set use-coredump-filter
1109 on|off". It allows to set whether GDB will read the content of the
1110 /proc/PID/coredump_filter file when generating a corefile.
1112 * The "info os" command on GNU/Linux can now display information on
1114 "info os cpus" Listing of all cpus/cores on the system
1116 * GDB has two new commands: "set serial parity odd|even|none" and
1117 "show serial parity". These allows to set or show parity for the
1120 * The "info source" command now displays the producer string if it was
1121 present in the debug info. This typically includes the compiler version
1122 and may include things like its command line arguments.
1124 * The "info dll", an alias of the "info sharedlibrary" command,
1125 is now available on all platforms.
1127 * Directory names supplied to the "set sysroot" commands may be
1128 prefixed with "target:" to tell GDB to access shared libraries from
1129 the target system, be it local or remote. This replaces the prefix
1130 "remote:". The default sysroot has been changed from "" to
1131 "target:". "remote:" is automatically converted to "target:" for
1132 backward compatibility.
1134 * The system root specified by "set sysroot" will be prepended to the
1135 filename of the main executable (if reported to GDB as absolute by
1136 the operating system) when starting processes remotely, and when
1137 attaching to already-running local or remote processes.
1139 * GDB now supports automatic location and retrieval of executable
1140 files from remote targets. Remote debugging can now be initiated
1141 using only a "target remote" or "target extended-remote" command
1142 (no "set sysroot" or "file" commands are required). See "New remote
1145 * The "dump" command now supports verilog hex format.
1147 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1149 * On GNU/Linux, GDB and gdbserver are now able to access executable
1150 and shared library files without a "set sysroot" command when
1151 attaching to processes running in different mount namespaces from
1152 the debugger. This makes it possible to attach to processes in
1153 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1154 See "New remote packets" below.
1156 * The "tui reg" command now provides completion for all of the
1157 available register groups, including target specific groups.
1159 * The HISTSIZE environment variable is no longer read when determining
1160 the size of GDB's command history. GDB now instead reads the dedicated
1161 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1162 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1167 ** Memory ports can now be unbuffered.
1171 ** gdb.Objfile objects have a new attribute "username",
1172 which is the name of the objfile as specified by the user,
1173 without, for example, resolving symlinks.
1174 ** You can now write frame unwinders in Python.
1175 ** gdb.Type objects have a new method "optimized_out",
1176 returning optimized out gdb.Value instance of this type.
1177 ** gdb.Value objects have new methods "reference_value" and
1178 "const_value" which return a reference to the value and a
1179 "const" version of the value respectively.
1183 maint print symbol-cache
1184 Print the contents of the symbol cache.
1186 maint print symbol-cache-statistics
1187 Print statistics of symbol cache usage.
1189 maint flush-symbol-cache
1190 Flush the contents of the symbol cache.
1194 Start branch trace recording using Branch Trace Store (BTS) format.
1197 Evaluate expression by using the compiler and print result.
1201 Explicit commands for enabling and disabling tui mode.
1204 set mpx bound on i386 and amd64
1205 Support for bound table investigation on Intel MPX enabled applications.
1209 Start branch trace recording using Intel Processor Trace format.
1212 Print information about branch tracing internals.
1214 maint btrace packet-history
1215 Print the raw branch tracing data.
1217 maint btrace clear-packet-history
1218 Discard the stored raw branch tracing data.
1221 Discard all branch tracing data. It will be fetched and processed
1222 anew by the next "record" command.
1227 Renamed from "set debug dwarf2-die".
1228 show debug dwarf-die
1229 Renamed from "show debug dwarf2-die".
1231 set debug dwarf-read
1232 Renamed from "set debug dwarf2-read".
1233 show debug dwarf-read
1234 Renamed from "show debug dwarf2-read".
1236 maint set dwarf always-disassemble
1237 Renamed from "maint set dwarf2 always-disassemble".
1238 maint show dwarf always-disassemble
1239 Renamed from "maint show dwarf2 always-disassemble".
1241 maint set dwarf max-cache-age
1242 Renamed from "maint set dwarf2 max-cache-age".
1243 maint show dwarf max-cache-age
1244 Renamed from "maint show dwarf2 max-cache-age".
1246 set debug dwarf-line
1247 show debug dwarf-line
1248 Control display of debugging info regarding DWARF line processing.
1251 show max-completions
1252 Set the maximum number of candidates to be considered during
1253 completion. The default value is 200. This limit allows GDB
1254 to avoid generating large completion lists, the computation of
1255 which can cause the debugger to become temporarily unresponsive.
1257 set history remove-duplicates
1258 show history remove-duplicates
1259 Control the removal of duplicate history entries.
1261 maint set symbol-cache-size
1262 maint show symbol-cache-size
1263 Control the size of the symbol cache.
1265 set|show record btrace bts buffer-size
1266 Set and show the size of the ring buffer used for branch tracing in
1268 The obtained size may differ from the requested size. Use "info
1269 record" to see the obtained buffer size.
1271 set debug linux-namespaces
1272 show debug linux-namespaces
1273 Control display of debugging info regarding Linux namespaces.
1275 set|show record btrace pt buffer-size
1276 Set and show the size of the ring buffer used for branch tracing in
1277 Intel Processor Trace format.
1278 The obtained size may differ from the requested size. Use "info
1279 record" to see the obtained buffer size.
1281 maint set|show btrace pt skip-pad
1282 Set and show whether PAD packets are skipped when computing the
1285 * The command 'thread apply all' can now support new option '-ascending'
1286 to call its specified command for all threads in ascending order.
1288 * Python/Guile scripting
1290 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1291 special section named `.debug_gdb_scripts'.
1293 * New remote packets
1295 qXfer:btrace-conf:read
1296 Return the branch trace configuration for the current thread.
1298 Qbtrace-conf:bts:size
1299 Set the requested ring buffer size for branch tracing in BTS format.
1302 Enable Intel Procesor Trace-based branch tracing for the current
1303 process. The remote stub reports support for this packet to GDB's
1306 Qbtrace-conf:pt:size
1307 Set the requested ring buffer size for branch tracing in Intel Processor
1311 Indicates a memory breakpoint instruction was executed, irrespective
1312 of whether it was GDB that planted the breakpoint or the breakpoint
1313 is hardcoded in the program. This is required for correct non-stop
1317 Indicates the target stopped for a hardware breakpoint. This is
1318 required for correct non-stop mode operation.
1321 Return information about files on the remote system.
1323 qXfer:exec-file:read
1324 Return the full absolute name of the file that was executed to
1325 create a process running on the remote system.
1328 Select the filesystem on which vFile: operations with filename
1329 arguments will operate. This is required for GDB to be able to
1330 access files on remote targets where the remote stub does not
1331 share a common filesystem with the inferior(s).
1334 Indicates that a fork system call was executed.
1337 Indicates that a vfork system call was executed.
1339 vforkdone stop reason
1340 Indicates that a vfork child of the specified process has executed
1341 an exec or exit, allowing the vfork parent to resume execution.
1343 fork-events and vfork-events features in qSupported
1344 The qSupported packet allows GDB to request support for fork and
1345 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1346 and the qSupported response can contain the corresponding
1347 'stubfeatures'. Set and show commands can be used to display
1348 whether these features are enabled.
1350 * Extended-remote fork events
1352 ** GDB now has support for fork events on extended-remote Linux
1353 targets. For targets with Linux kernels 2.5.60 and later, this
1354 enables follow-fork-mode and detach-on-fork for both fork and
1355 vfork, as well as fork and vfork catchpoints.
1357 * The info record command now shows the recording format and the
1358 branch tracing configuration for the current thread when using
1359 the btrace record target.
1360 For the BTS format, it shows the ring buffer size.
1362 * GDB now has support for DTrace USDT (Userland Static Defined
1363 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1365 * GDB now supports access to vector registers on S/390 GNU/Linux
1368 * Removed command line options
1370 -xdb HP-UX XDB compatibility mode.
1372 * Removed targets and native configurations
1374 HP/PA running HP-UX hppa*-*-hpux*
1375 Itanium running HP-UX ia64-*-hpux*
1377 * New configure options
1380 This configure option allows the user to build GDB with support for
1381 Intel Processor Trace (default: auto). This requires libipt.
1383 --with-libipt-prefix=PATH
1384 Specify the path to the version of libipt that GDB should use.
1385 $PATH/include should contain the intel-pt.h header and
1386 $PATH/lib should contain the libipt.so library.
1388 *** Changes in GDB 7.9.1
1392 ** Xmethods can now specify a result type.
1394 *** Changes in GDB 7.9
1396 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1400 ** You can now access frame registers from Python scripts.
1401 ** New attribute 'producer' for gdb.Symtab objects.
1402 ** gdb.Objfile objects have a new attribute "progspace",
1403 which is the gdb.Progspace object of the containing program space.
1404 ** gdb.Objfile objects have a new attribute "owner".
1405 ** gdb.Objfile objects have a new attribute "build_id",
1406 which is the build ID generated when the file was built.
1407 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1408 ** A new event "gdb.clear_objfiles" has been added, triggered when
1409 selecting a new file to debug.
1410 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1411 ** New function gdb.lookup_objfile.
1413 New events which are triggered when GDB modifies the state of the
1416 ** gdb.events.inferior_call_pre: Function call is about to be made.
1417 ** gdb.events.inferior_call_post: Function call has just been made.
1418 ** gdb.events.memory_changed: A memory location has been altered.
1419 ** gdb.events.register_changed: A register has been altered.
1421 * New Python-based convenience functions:
1423 ** $_caller_is(name [, number_of_frames])
1424 ** $_caller_matches(regexp [, number_of_frames])
1425 ** $_any_caller_is(name [, number_of_frames])
1426 ** $_any_caller_matches(regexp [, number_of_frames])
1428 * GDB now supports the compilation and injection of source code into
1429 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1430 to compile the source code to object code, and if successful, inject
1431 and execute that code within the current context of the inferior.
1432 Currently the C language is supported. The commands used to
1433 interface with this new feature are:
1435 compile code [-raw|-r] [--] [source code]
1436 compile file [-raw|-r] filename
1440 demangle [-l language] [--] name
1441 Demangle "name" in the specified language, or the current language
1442 if elided. This command is renamed from the "maint demangle" command.
1443 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1444 as "maint demangler-warning".
1446 queue-signal signal-name-or-number
1447 Queue a signal to be delivered to the thread when it is resumed.
1449 add-auto-load-scripts-directory directory
1450 Add entries to the list of directories from which to load auto-loaded
1453 maint print user-registers
1454 List all currently available "user" registers.
1456 compile code [-r|-raw] [--] [source code]
1457 Compile, inject, and execute in the inferior the executable object
1458 code produced by compiling the provided source code.
1460 compile file [-r|-raw] filename
1461 Compile and inject into the inferior the executable object code
1462 produced by compiling the source code stored in the filename
1465 * On resume, GDB now always passes the signal the program had stopped
1466 for to the thread the signal was sent to, even if the user changed
1467 threads before resuming. Previously GDB would often (but not
1468 always) deliver the signal to the thread that happens to be current
1471 * Conversely, the "signal" command now consistently delivers the
1472 requested signal to the current thread. GDB now asks for
1473 confirmation if the program had stopped for a signal and the user
1474 switched threads meanwhile.
1476 * "breakpoint always-inserted" modes "off" and "auto" merged.
1478 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1479 won't remove breakpoints from the target until all threads stop,
1480 even in non-stop mode. The "auto" mode has been removed, and "off"
1481 is now the default mode.
1485 set debug symbol-lookup
1486 show debug symbol-lookup
1487 Control display of debugging info regarding symbol lookup.
1491 ** The -list-thread-groups command outputs an exit-code field for
1492 inferiors that have exited.
1496 MIPS SDE mips*-sde*-elf*
1500 Support for these obsolete configurations has been removed.
1502 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1503 SGI Irix-5.x mips-*-irix5*
1504 SGI Irix-6.x mips-*-irix6*
1505 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1506 VAX running Ultrix vax-*-ultrix*
1508 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1509 and "assf"), have been removed. Use the "sharedlibrary" command, or
1510 its alias "share", instead.
1512 *** Changes in GDB 7.8
1514 * New command line options
1517 This is an alias for the --data-directory option.
1519 * GDB supports printing and modifying of variable length automatic arrays
1520 as specified in ISO C99.
1522 * The ARM simulator now supports instruction level tracing
1523 with or without disassembly.
1527 GDB now has support for scripting using Guile. Whether this is
1528 available is determined at configure time.
1529 Guile version 2.0 or greater is required.
1530 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1532 * New commands (for set/show, see "New options" below)
1536 Invoke CODE by passing it to the Guile interpreter.
1540 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1542 info auto-load guile-scripts [regexp]
1543 Print the list of automatically loaded Guile scripts.
1545 * The source command is now capable of sourcing Guile scripts.
1546 This feature is dependent on the debugger being built with Guile support.
1550 set print symbol-loading (off|brief|full)
1551 show print symbol-loading
1552 Control whether to print informational messages when loading symbol
1553 information for a file. The default is "full", but when debugging
1554 programs with large numbers of shared libraries the amount of output
1555 becomes less useful.
1557 set guile print-stack (none|message|full)
1558 show guile print-stack
1559 Show a stack trace when an error is encountered in a Guile script.
1561 set auto-load guile-scripts (on|off)
1562 show auto-load guile-scripts
1563 Control auto-loading of Guile script files.
1565 maint ada set ignore-descriptive-types (on|off)
1566 maint ada show ignore-descriptive-types
1567 Control whether the debugger should ignore descriptive types in Ada
1568 programs. The default is not to ignore the descriptive types. See
1569 the user manual for more details on descriptive types and the intended
1570 usage of this option.
1572 set auto-connect-native-target
1574 Control whether GDB is allowed to automatically connect to the
1575 native target for the run, attach, etc. commands when not connected
1576 to any target yet. See also "target native" below.
1578 set record btrace replay-memory-access (read-only|read-write)
1579 show record btrace replay-memory-access
1580 Control what memory accesses are allowed during replay.
1582 maint set target-async (on|off)
1583 maint show target-async
1584 This controls whether GDB targets operate in synchronous or
1585 asynchronous mode. Normally the default is asynchronous, if it is
1586 available; but this can be changed to more easily debug problems
1587 occurring only in synchronous mode.
1589 set mi-async (on|off)
1591 Control whether MI asynchronous mode is preferred. This supersedes
1592 "set target-async" of previous GDB versions.
1594 * "set target-async" is deprecated as a CLI option and is now an alias
1595 for "set mi-async" (only puts MI into async mode).
1597 * Background execution commands (e.g., "c&", "s&", etc.) are now
1598 possible ``out of the box'' if the target supports them. Previously
1599 the user would need to explicitly enable the possibility with the
1600 "set target-async on" command.
1602 * New features in the GDB remote stub, GDBserver
1604 ** New option --debug-format=option1[,option2,...] allows one to add
1605 additional text to each output. At present only timestamps
1606 are supported: --debug-format=timestamps.
1607 Timestamps can also be turned on with the
1608 "monitor set debug-format timestamps" command from GDB.
1610 * The 'record instruction-history' command now starts counting instructions
1611 at one. This also affects the instruction ranges reported by the
1612 'record function-call-history' command when given the /i modifier.
1614 * The command 'record function-call-history' supports a new modifier '/c' to
1615 indent the function names based on their call stack depth.
1616 The fields for the '/i' and '/l' modifier have been reordered.
1617 The source line range is now prefixed with 'at'.
1618 The instruction range is now prefixed with 'inst'.
1619 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1620 "record instruction-history" and "list" commands.
1622 * The ranges given as arguments to the 'record function-call-history' and
1623 'record instruction-history' commands are now inclusive.
1625 * The btrace record target now supports the 'record goto' command.
1626 For locations inside the execution trace, the back trace is computed
1627 based on the information stored in the execution trace.
1629 * The btrace record target supports limited reverse execution and replay.
1630 The target does not record data and therefore does not allow reading
1631 memory or registers.
1633 * The "catch syscall" command now works on s390*-linux* targets.
1635 * The "compare-sections" command is no longer specific to target
1636 remote. It now works with all targets.
1638 * All native targets are now consistently called "native".
1639 Consequently, the "target child", "target GNU", "target djgpp",
1640 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1641 commands have been replaced with "target native". The QNX/NTO port
1642 leaves the "procfs" target in place and adds a "native" target for
1643 consistency with other ports. The impact on users should be minimal
1644 as these commands previously either throwed an error, or were
1645 no-ops. The target's name is visible in the output of the following
1646 commands: "help target", "info target", "info files", "maint print
1649 * The "target native" command now connects to the native target. This
1650 can be used to launch native programs even when "set
1651 auto-connect-native-target" is set to off.
1653 * GDB now supports access to Intel MPX registers on GNU/Linux.
1655 * Support for Intel AVX-512 registers on GNU/Linux.
1656 Support displaying and modifying Intel AVX-512 registers
1657 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1659 * New remote packets
1661 qXfer:btrace:read's annex
1662 The qXfer:btrace:read packet supports a new annex 'delta' to read
1663 branch trace incrementally.
1667 ** Valid Python operations on gdb.Value objects representing
1668 structs/classes invoke the corresponding overloaded operators if
1670 ** New `Xmethods' feature in the Python API. Xmethods are
1671 additional methods or replacements for existing methods of a C++
1672 class. This feature is useful for those cases where a method
1673 defined in C++ source code could be inlined or optimized out by
1674 the compiler, making it unavailable to GDB.
1677 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1679 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1680 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1681 its alias "share", instead.
1683 * The commands "set remotebaud" and "show remotebaud" are no longer
1684 supported. Use "set serial baud" and "show serial baud" (respectively)
1689 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1690 target-async". The latter is left as a deprecated alias of the
1691 former for backward compatibility. If the target supports it,
1692 CLI background execution commands are now always possible by
1693 default, independently of whether the frontend stated a
1694 preference for asynchronous execution with "-gdb-set mi-async".
1695 Previously "-gdb-set target-async off" affected both MI execution
1696 commands and CLI execution commands.
1698 *** Changes in GDB 7.7
1700 * Improved support for process record-replay and reverse debugging on
1701 arm*-linux* targets. Support for thumb32 and syscall instruction
1702 recording has been added.
1704 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1706 * GDB now supports Fission DWP file format version 2.
1707 http://gcc.gnu.org/wiki/DebugFission
1709 * New convenience function "$_isvoid", to check whether an expression
1710 is void. A void expression is an expression where the type of the
1711 result is "void". For example, some convenience variables may be
1712 "void" when evaluated (e.g., "$_exitcode" before the execution of
1713 the program being debugged; or an undefined convenience variable).
1714 Another example, when calling a function whose return type is
1717 * The "maintenance print objfiles" command now takes an optional regexp.
1719 * The "catch syscall" command now works on arm*-linux* targets.
1721 * GDB now consistently shows "<not saved>" when printing values of
1722 registers the debug info indicates have not been saved in the frame
1723 and there's nowhere to retrieve them from
1724 (callee-saved/call-clobbered registers):
1729 (gdb) info registers rax
1732 Before, the former would print "<optimized out>", and the latter
1733 "*value not available*".
1735 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1740 ** Frame filters and frame decorators have been added.
1741 ** Temporary breakpoints are now supported.
1742 ** Line tables representation has been added.
1743 ** New attribute 'parent_type' for gdb.Field objects.
1744 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1745 ** New attribute 'name' for gdb.Type objects.
1749 Nios II ELF nios2*-*-elf
1750 Nios II GNU/Linux nios2*-*-linux
1751 Texas Instruments MSP430 msp430*-*-elf
1753 * Removed native configurations
1755 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1756 been removed. ELF variants of these configurations are kept supported.
1758 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1759 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1760 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1761 i[34567]86-*-openbsd3.[0-3]
1762 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1763 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1764 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1768 Like "catch throw", but catches a re-thrown exception.
1769 maint check-psymtabs
1770 Renamed from old "maint check-symtabs".
1772 Perform consistency checks on symtabs.
1773 maint expand-symtabs
1774 Expand symtabs matching an optional regexp.
1777 Display the details of GDB configure-time options.
1779 maint set|show per-command
1780 maint set|show per-command space
1781 maint set|show per-command time
1782 maint set|show per-command symtab
1783 Enable display of per-command gdb resource usage.
1785 remove-symbol-file FILENAME
1786 remove-symbol-file -a ADDRESS
1787 Remove a symbol file added via add-symbol-file. The file to remove
1788 can be identified by its filename or by an address that lies within
1789 the boundaries of this symbol file in memory.
1792 info exceptions REGEXP
1793 Display the list of Ada exceptions defined in the program being
1794 debugged. If provided, only the exceptions whose names match REGEXP
1799 set debug symfile off|on
1801 Control display of debugging info regarding reading symbol files and
1802 symbol tables within those files
1804 set print raw frame-arguments
1805 show print raw frame-arguments
1806 Set/show whether to print frame arguments in raw mode,
1807 disregarding any defined pretty-printers.
1809 set remote trace-status-packet
1810 show remote trace-status-packet
1811 Set/show the use of remote protocol qTStatus packet.
1815 Control display of debugging messages related to Nios II targets.
1819 Control whether target-assisted range stepping is enabled.
1821 set startup-with-shell
1822 show startup-with-shell
1823 Specifies whether Unix child processes are started via a shell or
1828 Use the target memory cache for accesses to the code segment. This
1829 improves performance of remote debugging (particularly disassembly).
1831 * You can now use a literal value 'unlimited' for options that
1832 interpret 0 or -1 as meaning "unlimited". E.g., "set
1833 trace-buffer-size unlimited" is now an alias for "set
1834 trace-buffer-size -1" and "set height unlimited" is now an alias for
1837 * The "set debug symtab-create" debugging option of GDB has been changed to
1838 accept a verbosity level. 0 means "off", 1 provides basic debugging
1839 output, and values of 2 or greater provides more verbose output.
1841 * New command-line options
1843 Display the details of GDB configure-time options.
1845 * The command 'tsave' can now support new option '-ctf' to save trace
1846 buffer in Common Trace Format.
1848 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1851 * GDB now implements the the C++ 'typeid' operator.
1853 * The new convenience variable $_exception holds the exception being
1854 thrown or caught at an exception-related catchpoint.
1856 * The exception-related catchpoints, like "catch throw", now accept a
1857 regular expression which can be used to filter exceptions by type.
1859 * The new convenience variable $_exitsignal is automatically set to
1860 the terminating signal number when the program being debugged dies
1861 due to an uncaught signal.
1865 ** All MI commands now accept an optional "--language" option.
1866 Support for this feature can be verified by using the "-list-features"
1867 command, which should contain "language-option".
1869 ** The new command -info-gdb-mi-command allows the user to determine
1870 whether a GDB/MI command is supported or not.
1872 ** The "^error" result record returned when trying to execute an undefined
1873 GDB/MI command now provides a variable named "code" whose content is the
1874 "undefined-command" error code. Support for this feature can be verified
1875 by using the "-list-features" command, which should contain
1876 "undefined-command-error-code".
1878 ** The -trace-save MI command can optionally save trace buffer in Common
1881 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1883 ** The command -data-list-register-values now accepts an optional
1884 "--skip-unavailable" option. When used, only the available registers
1887 ** The new command -trace-frame-collected dumps collected variables,
1888 computed expressions, tvars, memory and registers in a traceframe.
1890 ** The commands -stack-list-locals, -stack-list-arguments and
1891 -stack-list-variables now accept an option "--skip-unavailable".
1892 When used, only the available locals or arguments are displayed.
1894 ** The -exec-run command now accepts an optional "--start" option.
1895 When used, the command follows the same semantics as the "start"
1896 command, stopping the program's execution at the start of its
1897 main subprogram. Support for this feature can be verified using
1898 the "-list-features" command, which should contain
1899 "exec-run-start-option".
1901 ** The new commands -catch-assert and -catch-exceptions insert
1902 catchpoints stopping the program when Ada exceptions are raised.
1904 ** The new command -info-ada-exceptions provides the equivalent of
1905 the new "info exceptions" command.
1907 * New system-wide configuration scripts
1908 A GDB installation now provides scripts suitable for use as system-wide
1909 configuration scripts for the following systems:
1913 * GDB now supports target-assigned range stepping with remote targets.
1914 This improves the performance of stepping source lines by reducing
1915 the number of control packets from/to GDB. See "New remote packets"
1918 * GDB now understands the element 'tvar' in the XML traceframe info.
1919 It has the id of the collected trace state variables.
1921 * On S/390 targets that provide the transactional-execution feature,
1922 the program interruption transaction diagnostic block (TDB) is now
1923 represented as a number of additional "registers" in GDB.
1925 * New remote packets
1929 The vCont packet supports a new 'r' action, that tells the remote
1930 stub to step through an address range itself, without GDB
1931 involvemement at each single-step.
1933 qXfer:libraries-svr4:read's annex
1934 The previously unused annex of the qXfer:libraries-svr4:read packet
1935 is now used to support passing an argument list. The remote stub
1936 reports support for this argument list to GDB's qSupported query.
1937 The defined arguments are "start" and "prev", used to reduce work
1938 necessary for library list updating, resulting in significant
1941 * New features in the GDB remote stub, GDBserver
1943 ** GDBserver now supports target-assisted range stepping. Currently
1944 enabled on x86/x86_64 GNU/Linux targets.
1946 ** GDBserver now adds element 'tvar' in the XML in the reply to
1947 'qXfer:traceframe-info:read'. It has the id of the collected
1948 trace state variables.
1950 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1953 * New 'z' formatter for printing and examining memory, this displays the
1954 value as hexadecimal zero padded on the left to the size of the type.
1956 * GDB can now use Windows x64 unwinding data.
1958 * The "set remotebaud" command has been replaced by "set serial baud".
1959 Similarly, "show remotebaud" has been replaced by "show serial baud".
1960 The "set remotebaud" and "show remotebaud" commands are still available
1961 to provide backward compatibility with older versions of GDB.
1963 *** Changes in GDB 7.6
1965 * Target record has been renamed to record-full.
1966 Record/replay is now enabled with the "record full" command.
1967 This also affects settings that are associated with full record/replay
1968 that have been moved from "set/show record" to "set/show record full":
1970 set|show record full insn-number-max
1971 set|show record full stop-at-limit
1972 set|show record full memory-query
1974 * A new record target "record-btrace" has been added. The new target
1975 uses hardware support to record the control-flow of a process. It
1976 does not support replaying the execution, but it implements the
1977 below new commands for investigating the recorded execution log.
1978 This new recording method can be enabled using:
1982 The "record-btrace" target is only available on Intel Atom processors
1983 and requires a Linux kernel 2.6.32 or later.
1985 * Two new commands have been added for record/replay to give information
1986 about the recorded execution without having to replay the execution.
1987 The commands are only supported by "record btrace".
1989 record instruction-history prints the execution history at
1990 instruction granularity
1992 record function-call-history prints the execution history at
1993 function granularity
1995 * New native configurations
1997 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1998 FreeBSD/powerpc powerpc*-*-freebsd
1999 x86_64/Cygwin x86_64-*-cygwin*
2000 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2004 ARM AArch64 aarch64*-*-elf
2005 ARM AArch64 GNU/Linux aarch64*-*-linux
2006 Lynx 178 PowerPC powerpc-*-lynx*178
2007 x86_64/Cygwin x86_64-*-cygwin*
2008 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2010 * If the configured location of system.gdbinit file (as given by the
2011 --with-system-gdbinit option at configure time) is in the
2012 data-directory (as specified by --with-gdb-datadir at configure
2013 time) or in one of its subdirectories, then GDB will look for the
2014 system-wide init file in the directory specified by the
2015 --data-directory command-line option.
2017 * New command line options:
2019 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2020 other initialization files, unlike -nx which disables all of them.
2022 * Removed command line options
2024 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2027 * The 'ptype' and 'whatis' commands now accept an argument to control
2030 * 'info proc' now works on some core files.
2034 ** Vectors can be created with gdb.Type.vector.
2036 ** Python's atexit.register now works in GDB.
2038 ** Types can be pretty-printed via a Python API.
2040 ** Python 3 is now supported (in addition to Python 2.4 or later)
2042 ** New class gdb.Architecture exposes GDB's internal representation
2043 of architecture in the Python API.
2045 ** New method Frame.architecture returns the gdb.Architecture object
2046 corresponding to the frame's architecture.
2048 * New Python-based convenience functions:
2050 ** $_memeq(buf1, buf2, length)
2051 ** $_streq(str1, str2)
2053 ** $_regex(str, regex)
2055 * The 'cd' command now defaults to using '~' (the home directory) if not
2058 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2059 default for GCC since November 2000.
2061 * The command 'forward-search' can now be abbreviated as 'fo'.
2063 * The command 'info tracepoints' can now display 'installed on target'
2064 or 'not installed on target' for each non-pending location of tracepoint.
2066 * New configure options
2068 --enable-libmcheck/--disable-libmcheck
2069 By default, development versions are built with -lmcheck on hosts
2070 that support it, in order to help track memory corruption issues.
2071 Release versions, on the other hand, are built without -lmcheck
2072 by default. The --enable-libmcheck/--disable-libmcheck configure
2073 options allow the user to override that default.
2074 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2075 This configure option allows the user to build GDB with
2076 libbabeltrace using which GDB can read Common Trace Format data.
2078 * New commands (for set/show, see "New options" below)
2081 Catch signals. This is similar to "handle", but allows commands and
2082 conditions to be attached.
2085 List the BFDs known to GDB.
2087 python-interactive [command]
2089 Start a Python interactive prompt, or evaluate the optional command
2090 and print the result of expressions.
2093 "py" is a new alias for "python".
2095 enable type-printer [name]...
2096 disable type-printer [name]...
2097 Enable or disable type printers.
2101 ** For the Renesas Super-H architecture, the "regs" command has been removed
2102 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2107 set print type methods (on|off)
2108 show print type methods
2109 Control whether method declarations are displayed by "ptype".
2110 The default is to show them.
2112 set print type typedefs (on|off)
2113 show print type typedefs
2114 Control whether typedef definitions are displayed by "ptype".
2115 The default is to show them.
2117 set filename-display basename|relative|absolute
2118 show filename-display
2119 Control the way in which filenames is displayed.
2120 The default is "relative", which preserves previous behavior.
2122 set trace-buffer-size
2123 show trace-buffer-size
2124 Request target to change the size of trace buffer.
2126 set remote trace-buffer-size-packet auto|on|off
2127 show remote trace-buffer-size-packet
2128 Control the use of the remote protocol `QTBuffer:size' packet.
2132 Control display of debugging messages related to ARM AArch64.
2135 set debug coff-pe-read
2136 show debug coff-pe-read
2137 Control display of debugging messages related to reading of COFF/PE
2142 Control display of debugging messages related to Mach-O symbols
2145 set debug notification
2146 show debug notification
2147 Control display of debugging info for async remote notification.
2151 ** Command parameter changes are now notified using new async record
2152 "=cmd-param-changed".
2153 ** Trace frame changes caused by command "tfind" are now notified using
2154 new async record "=traceframe-changed".
2155 ** The creation, deletion and modification of trace state variables
2156 are now notified using new async records "=tsv-created",
2157 "=tsv-deleted" and "=tsv-modified".
2158 ** The start and stop of process record are now notified using new
2159 async record "=record-started" and "=record-stopped".
2160 ** Memory changes are now notified using new async record
2162 ** The data-disassemble command response will include a "fullname" field
2163 containing the absolute file name when source has been requested.
2164 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2165 command, to allow pattern filling of memory areas.
2166 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2167 library load/unload events.
2168 ** The response to breakpoint commands and breakpoint async records
2169 includes an "installed" field containing a boolean state about each
2170 non-pending tracepoint location is whether installed on target or not.
2171 ** Output of the "-trace-status" command includes a "trace-file" field
2172 containing the name of the trace file being examined. This field is
2173 optional, and only present when examining a trace file.
2174 ** The "fullname" field is now always present along with the "file" field,
2175 even if the file cannot be found by GDB.
2177 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2178 You must have the LZMA library available when configuring GDB for this
2179 feature to be enabled. For more information, see:
2180 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2182 * New remote packets
2185 Set the size of trace buffer. The remote stub reports support for this
2186 packet to gdb's qSupported query.
2189 Enable Branch Trace Store (BTS)-based branch tracing for the current
2190 thread. The remote stub reports support for this packet to gdb's
2194 Disable branch tracing for the current thread. The remote stub reports
2195 support for this packet to gdb's qSupported query.
2198 Read the traced branches for the current thread. The remote stub
2199 reports support for this packet to gdb's qSupported query.
2201 *** Changes in GDB 7.5
2203 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2204 for more x32 ABI info.
2206 * GDB now supports access to MIPS DSP registers on Linux targets.
2208 * GDB now supports debugging microMIPS binaries.
2210 * The "info os" command on GNU/Linux can now display information on
2211 several new classes of objects managed by the operating system:
2212 "info os procgroups" lists process groups
2213 "info os files" lists file descriptors
2214 "info os sockets" lists internet-domain sockets
2215 "info os shm" lists shared-memory regions
2216 "info os semaphores" lists semaphores
2217 "info os msg" lists message queues
2218 "info os modules" lists loaded kernel modules
2220 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2221 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2222 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2223 options and inspect the probe arguments using the new $_probe_arg family
2224 of convenience variables. You can obtain more information about SystemTap
2225 in <http://sourceware.org/systemtap/>.
2227 * GDB now supports reversible debugging on ARM, it allows you to
2228 debug basic ARM and THUMB instructions, and provides
2229 record/replay support.
2231 * The option "symbol-reloading" has been deleted as it is no longer used.
2235 ** GDB commands implemented in Python can now be put in command class
2238 ** The "maint set python print-stack on|off" is now deleted.
2240 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2241 apply "flag enum"-style pretty-printing to any enum.
2243 ** gdb.lookup_symbol can now work when there is no current frame.
2245 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2246 the source at which the symbol was defined.
2248 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2249 method 'value'. The former indicates whether the symbol needs a
2250 frame in order to compute its value, and the latter computes the
2253 ** A new method 'referenced_value' on gdb.Value objects which can
2254 dereference pointer as well as C++ reference values.
2256 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2257 which return the global and static blocks (as gdb.Block objects),
2258 of the underlying symbol table, respectively.
2260 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2261 object associated with a PC value.
2263 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2264 of the address range occupied by code for the current source line.
2266 * Go language support.
2267 GDB now supports debugging programs written in the Go programming
2270 * GDBserver now supports stdio connections.
2271 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2273 * The binary "gdbtui" can no longer be built or installed.
2274 Use "gdb -tui" instead.
2276 * GDB will now print "flag" enums specially. A flag enum is one where
2277 all the enumerator values have no bits in common when pairwise
2278 "and"ed. When printing a value whose type is a flag enum, GDB will
2279 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2280 (gdb) print (enum E) 3
2283 * The filename part of a linespec will now match trailing components
2284 of a source file name. For example, "break gcc/expr.c:1000" will
2285 now set a breakpoint in build/gcc/expr.c, but not
2286 build/libcpp/expr.c.
2288 * The "info proc" and "generate-core-file" commands will now also
2289 work on remote targets connected to GDBserver on Linux.
2291 * The command "info catch" has been removed. It has been disabled
2292 since December 2007.
2294 * The "catch exception" and "catch assert" commands now accept
2295 a condition at the end of the command, much like the "break"
2296 command does. For instance:
2298 (gdb) catch exception Constraint_Error if Barrier = True
2300 Previously, it was possible to add a condition to such catchpoints,
2301 but it had to be done as a second step, after the catchpoint had been
2302 created, using the "condition" command.
2304 * The "info static-tracepoint-marker" command will now also work on
2305 native Linux targets with in-process agent.
2307 * GDB can now set breakpoints on inlined functions.
2309 * The .gdb_index section has been updated to include symbols for
2310 inlined functions. GDB will ignore older .gdb_index sections by
2311 default, which could cause symbol files to be loaded more slowly
2312 until their .gdb_index sections can be recreated. The new command
2313 "set use-deprecated-index-sections on" will cause GDB to use any older
2314 .gdb_index sections it finds. This will restore performance, but the
2315 ability to set breakpoints on inlined functions will be lost in symbol
2316 files with older .gdb_index sections.
2318 The .gdb_index section has also been updated to record more information
2319 about each symbol. This speeds up the "info variables", "info functions"
2320 and "info types" commands when used with programs having the .gdb_index
2321 section, as well as speeding up debugging with shared libraries using
2322 the .gdb_index section.
2324 * Ada support for GDB/MI Variable Objects has been added.
2326 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2331 ** New command -info-os is the MI equivalent of "info os".
2333 ** Output logs ("set logging" and related) now include MI output.
2337 ** "set use-deprecated-index-sections on|off"
2338 "show use-deprecated-index-sections on|off"
2339 Controls the use of deprecated .gdb_index sections.
2341 ** "catch load" and "catch unload" can be used to stop when a shared
2342 library is loaded or unloaded, respectively.
2344 ** "enable count" can be used to auto-disable a breakpoint after
2347 ** "info vtbl" can be used to show the virtual method tables for
2348 C++ and Java objects.
2350 ** "explore" and its sub commands "explore value" and "explore type"
2351 can be used to recursively explore values and types of
2352 expressions. These commands are available only if GDB is
2353 configured with '--with-python'.
2355 ** "info auto-load" shows status of all kinds of auto-loaded files,
2356 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2357 sequences of commands files, "info auto-load python-scripts"
2358 shows status of auto-loading Python script files,
2359 "info auto-load local-gdbinit" shows status of loading init file
2360 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2361 status of inferior specific thread debugging shared library loading.
2363 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2364 and "show auto-load-scripts" commands have been deprecated, use their
2365 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2366 and "show auto-load python-scripts" counterparts instead.
2368 ** "dprintf location,format,args..." creates a dynamic printf, which
2369 is basically a breakpoint that does a printf and immediately
2370 resumes your program's execution, so it is like a printf that you
2371 can insert dynamically at runtime instead of at compiletime.
2373 ** "set print symbol"
2375 Controls whether GDB attempts to display the symbol, if any,
2376 corresponding to addresses it prints. This defaults to "on", but
2377 you can set it to "off" to restore GDB's previous behavior.
2379 * Deprecated commands
2381 ** For the Renesas Super-H architecture, the "regs" command has been
2382 deprecated, and "info all-registers" should be used instead.
2386 Renesas RL78 rl78-*-elf
2387 HP OpenVMS ia64 ia64-hp-openvms*
2389 * GDBserver supports evaluation of breakpoint conditions. When
2390 support is advertised by GDBserver, GDB may be told to send the
2391 breakpoint conditions in bytecode form to GDBserver. GDBserver
2392 will only report the breakpoint trigger to GDB when its condition
2397 set mips compression
2398 show mips compression
2399 Select the compressed ISA encoding used in functions that have no symbol
2400 information available. The encoding can be set to either of:
2403 and is updated automatically from ELF file flags if available.
2405 set breakpoint condition-evaluation
2406 show breakpoint condition-evaluation
2407 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2408 GDBserver ("target"). Default option "auto" chooses the most efficient
2410 This option can improve debugger efficiency depending on the speed of the
2414 Disable auto-loading globally.
2417 Show auto-loading setting of all kinds of auto-loaded files.
2419 set auto-load gdb-scripts on|off
2420 show auto-load gdb-scripts
2421 Control auto-loading of GDB canned sequences of commands files.
2423 set auto-load python-scripts on|off
2424 show auto-load python-scripts
2425 Control auto-loading of Python script files.
2427 set auto-load local-gdbinit on|off
2428 show auto-load local-gdbinit
2429 Control loading of init file (.gdbinit) from current directory.
2431 set auto-load libthread-db on|off
2432 show auto-load libthread-db
2433 Control auto-loading of inferior specific thread debugging shared library.
2435 set auto-load scripts-directory <dir1>[:<dir2>...]
2436 show auto-load scripts-directory
2437 Set a list of directories from which to load auto-loaded scripts.
2438 Automatically loaded Python scripts and GDB scripts are located in one
2439 of the directories listed by this option.
2440 The delimiter (':' above) may differ according to the host platform.
2442 set auto-load safe-path <dir1>[:<dir2>...]
2443 show auto-load safe-path
2444 Set a list of directories from which it is safe to auto-load files.
2445 The delimiter (':' above) may differ according to the host platform.
2447 set debug auto-load on|off
2448 show debug auto-load
2449 Control display of debugging info for auto-loading the files above.
2451 set dprintf-style gdb|call|agent
2453 Control the way in which a dynamic printf is performed; "gdb"
2454 requests a GDB printf command, while "call" causes dprintf to call a
2455 function in the inferior. "agent" requests that the target agent
2456 (such as GDBserver) do the printing.
2458 set dprintf-function <expr>
2459 show dprintf-function
2460 set dprintf-channel <expr>
2461 show dprintf-channel
2462 Set the function and optional first argument to the call when using
2463 the "call" style of dynamic printf.
2465 set disconnected-dprintf on|off
2466 show disconnected-dprintf
2467 Control whether agent-style dynamic printfs continue to be in effect
2468 after GDB disconnects.
2470 * New configure options
2472 --with-auto-load-dir
2473 Configure default value for the 'set auto-load scripts-directory'
2474 setting above. It defaults to '$debugdir:$datadir/auto-load',
2475 $debugdir representing global debugging info directories (available
2476 via 'show debug-file-directory') and $datadir representing GDB's data
2477 directory (available via 'show data-directory').
2479 --with-auto-load-safe-path
2480 Configure default value for the 'set auto-load safe-path' setting
2481 above. It defaults to the --with-auto-load-dir setting.
2483 --without-auto-load-safe-path
2484 Set 'set auto-load safe-path' to '/', effectively disabling this
2487 * New remote packets
2489 z0/z1 conditional breakpoints extension
2491 The z0/z1 breakpoint insertion packets have been extended to carry
2492 a list of conditional expressions over to the remote stub depending on the
2493 condition evaluation mode. The use of this extension can be controlled
2494 via the "set remote conditional-breakpoints-packet" command.
2498 Specify the signals which the remote stub may pass to the debugged
2499 program without GDB involvement.
2501 * New command line options
2503 --init-command=FILE, -ix Like --command, -x but execute it
2504 before loading inferior.
2505 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2506 execute it before loading inferior.
2508 *** Changes in GDB 7.4
2510 * GDB now handles ambiguous linespecs more consistently; the existing
2511 FILE:LINE support has been expanded to other types of linespecs. A
2512 breakpoint will now be set on all matching locations in all
2513 inferiors, and locations will be added or removed according to
2516 * GDB now allows you to skip uninteresting functions and files when
2517 stepping with the "skip function" and "skip file" commands.
2519 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2520 and "show remote hardware-watchpoint-length-limit". These allows to
2521 set or show the maximum length limit (in bytes) of a remote
2522 target hardware watchpoint.
2524 This allows e.g. to use "unlimited" hardware watchpoints with the
2525 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2526 watchpoints are slower than real hardware watchpoints but are
2527 significantly faster than gdb software watchpoints.
2531 ** The register_pretty_printer function in module gdb.printing now takes
2532 an optional `replace' argument. If True, the new printer replaces any
2535 ** The "maint set python print-stack on|off" command has been
2536 deprecated and will be deleted in GDB 7.5.
2537 A new command: "set python print-stack none|full|message" has
2538 replaced it. Additionally, the default for "print-stack" is
2539 now "message", which just prints the error message without
2542 ** A prompt substitution hook (prompt_hook) is now available to the
2545 ** A new Python module, gdb.prompt has been added to the GDB Python
2546 modules library. This module provides functionality for
2547 escape sequences in prompts (used by set/show
2548 extended-prompt). These escape sequences are replaced by their
2549 corresponding value.
2551 ** Python commands and convenience-functions located in
2552 'data-directory'/python/gdb/command and
2553 'data-directory'/python/gdb/function are now automatically loaded
2556 ** Blocks now provide four new attributes. global_block and
2557 static_block will return the global and static blocks
2558 respectively. is_static and is_global are boolean attributes
2559 that indicate if the block is one of those two types.
2561 ** Symbols now provide the "type" attribute, the type of the symbol.
2563 ** The "gdb.breakpoint" function has been deprecated in favor of
2566 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2567 of a function. This class is based on the "finish" command
2568 available in the CLI.
2570 ** Type objects for struct and union types now allow access to
2571 the fields using standard Python dictionary (mapping) methods.
2572 For example, "some_type['myfield']" now works, as does
2573 "some_type.items()".
2575 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2578 ** A new function, "deep_items" has been added to the gdb.types
2579 module in the GDB Python modules library. This function returns
2580 an iterator over the fields of a struct or union type. Unlike
2581 the standard Python "iteritems" method, it will recursively traverse
2582 any anonymous fields.
2586 ** "*stopped" events can report several new "reason"s, such as
2589 ** Breakpoint changes are now notified using new async records, like
2590 "=breakpoint-modified".
2592 ** New command -ada-task-info.
2594 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2595 $sdir specifies the default system locations of shared libraries.
2596 $pdir specifies the directory where the libpthread used by the application
2599 GDB no longer looks in $sdir and $pdir after it has searched the directories
2600 mentioned in libthread-db-search-path. If you want to search those
2601 directories, they must be specified in libthread-db-search-path.
2602 The default value of libthread-db-search-path on GNU/Linux and Solaris
2603 systems is now "$sdir:$pdir".
2605 $pdir is not supported by gdbserver, it is currently ignored.
2606 $sdir is supported by gdbserver.
2608 * New configure option --with-iconv-bin.
2609 When using the internationalization support like the one in the GNU C
2610 library, GDB will invoke the "iconv" program to get a list of supported
2611 character sets. If this program lives in a non-standard location, one can
2612 use this option to specify where to find it.
2614 * When natively debugging programs on PowerPC BookE processors running
2615 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2616 watchpoints, which specify a mask in addition to an address to watch.
2617 The mask specifies that some bits of an address (the bits which are
2618 reset in the mask) should be ignored when matching the address accessed
2619 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2620 section in the user manual for more details.
2622 * The new option --once causes GDBserver to stop listening for connections once
2623 the first connection is made. The listening port used by GDBserver will
2624 become available after that.
2626 * New commands "info macros" and "alias" have been added.
2628 * New function parameters suffix @entry specifies value of function parameter
2629 at the time the function got called. Entry values are available only since
2635 "!" is now an alias of the "shell" command.
2636 Note that no space is needed between "!" and SHELL COMMAND.
2640 watch EXPRESSION mask MASK_VALUE
2641 The watch command now supports the mask argument which allows creation
2642 of masked watchpoints, if the current architecture supports this feature.
2644 info auto-load-scripts [REGEXP]
2645 This command was formerly named "maintenance print section-scripts".
2646 It is now generally useful and is no longer a maintenance-only command.
2648 info macro [-all] [--] MACRO
2649 The info macro command has new options `-all' and `--'. The first for
2650 printing all definitions of a macro. The second for explicitly specifying
2651 the end of arguments and the beginning of the macro name in case the macro
2652 name starts with a hyphen.
2654 collect[/s] EXPRESSIONS
2655 The tracepoint collect command now takes an optional modifier "/s"
2656 that directs it to dereference pointer-to-character types and
2657 collect the bytes of memory up to a zero byte. The behavior is
2658 similar to what you see when you use the regular print command on a
2659 string. An optional integer following the "/s" sets a bound on the
2660 number of bytes that will be collected.
2663 The trace start command now interprets any supplied arguments as a
2664 note to be recorded with the trace run, with an effect similar to
2665 setting the variable trace-notes.
2668 The trace stop command now interprets any arguments as a note to be
2669 mentioned along with the tstatus report that the trace was stopped
2670 with a command. The effect is similar to setting the variable
2673 * Tracepoints can now be enabled and disabled at any time after a trace
2674 experiment has been started using the standard "enable" and "disable"
2675 commands. It is now possible to start a trace experiment with no enabled
2676 tracepoints; GDB will display a warning, but will allow the experiment to
2677 begin, assuming that tracepoints will be enabled as needed while the trace
2680 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2681 locations with 4-byte instructions, when they were previously
2682 limited to locations with instructions of 5 bytes or longer.
2686 set debug dwarf2-read
2687 show debug dwarf2-read
2688 Turns on or off display of debugging messages related to reading
2689 DWARF debug info. The default is off.
2691 set debug symtab-create
2692 show debug symtab-create
2693 Turns on or off display of debugging messages related to symbol table
2694 creation. The default is off.
2697 show extended-prompt
2698 Set the GDB prompt, and allow escape sequences to be inserted to
2699 display miscellaneous information (see 'help set extended-prompt'
2700 for the list of sequences). This prompt (and any information
2701 accessed through the escape sequences) is updated every time the
2702 prompt is displayed.
2704 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2705 show print entry-values
2706 Set printing of frame argument values at function entry. In some cases
2707 GDB can determine the value of function argument which was passed by the
2708 function caller, even if the value was modified inside the called function.
2710 set debug entry-values
2711 show debug entry-values
2712 Control display of debugging info for determining frame argument values at
2713 function entry and virtual tail call frames.
2715 set basenames-may-differ
2716 show basenames-may-differ
2717 Set whether a source file may have multiple base names.
2718 (A "base name" is the name of a file with the directory part removed.
2719 Example: The base name of "/home/user/hello.c" is "hello.c".)
2720 If set, GDB will canonicalize file names (e.g., expand symlinks)
2721 before comparing them. Canonicalization is an expensive operation,
2722 but it allows the same file be known by more than one base name.
2723 If not set (the default), all source files are assumed to have just
2724 one base name, and gdb will do file name comparisons more efficiently.
2730 Set a user name and notes for the current and any future trace runs.
2731 This is useful for long-running and/or disconnected traces, to
2732 inform others (or yourself) as to who is running the trace, supply
2733 contact information, or otherwise explain what is going on.
2735 set trace-stop-notes
2736 show trace-stop-notes
2737 Set a note attached to the trace run, that is displayed when the
2738 trace has been stopped by a tstop command. This is useful for
2739 instance as an explanation, if you are stopping a trace run that was
2740 started by someone else.
2742 * New remote packets
2746 Dynamically enable a tracepoint in a started trace experiment.
2750 Dynamically disable a tracepoint in a started trace experiment.
2754 Set the user and notes of the trace run.
2758 Query the current status of a tracepoint.
2762 Query the minimum length of instruction at which a fast tracepoint may
2765 * Dcache size (number of lines) and line-size are now runtime-configurable
2766 via "set dcache line" and "set dcache line-size" commands.
2770 Texas Instruments TMS320C6x tic6x-*-*
2774 Renesas RL78 rl78-*-elf
2776 *** Changes in GDB 7.3.1
2778 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2780 *** Changes in GDB 7.3
2782 * GDB has a new command: "thread find [REGEXP]".
2783 It finds the thread id whose name, target id, or thread extra info
2784 matches the given regular expression.
2786 * The "catch syscall" command now works on mips*-linux* targets.
2788 * The -data-disassemble MI command now supports modes 2 and 3 for
2789 dumping the instruction opcodes.
2791 * New command line options
2793 -data-directory DIR Specify DIR as the "data-directory".
2794 This is mostly for testing purposes.
2796 * The "maint set python auto-load on|off" command has been renamed to
2797 "set auto-load-scripts on|off".
2799 * GDB has a new command: "set directories".
2800 It is like the "dir" command except that it replaces the
2801 source path list instead of augmenting it.
2803 * GDB now understands thread names.
2805 On GNU/Linux, "info threads" will display the thread name as set by
2806 prctl or pthread_setname_np.
2808 There is also a new command, "thread name", which can be used to
2809 assign a name internally for GDB to display.
2812 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2813 has been integrated into GDB.
2817 ** The function gdb.Write now accepts an optional keyword 'stream'.
2818 This keyword, when provided, will direct the output to either
2819 stdout, stderr, or GDB's logging output.
2821 ** Parameters can now be be sub-classed in Python, and in particular
2822 you may implement the get_set_doc and get_show_doc functions.
2823 This improves how Parameter set/show documentation is processed
2824 and allows for more dynamic content.
2826 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2827 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2828 have an is_valid method.
2830 ** Breakpoints can now be sub-classed in Python, and in particular
2831 you may implement a 'stop' function that is executed each time
2832 the inferior reaches that breakpoint.
2834 ** New function gdb.lookup_global_symbol looks up a global symbol.
2836 ** GDB values in Python are now callable if the value represents a
2837 function. For example, if 'some_value' represents a function that
2838 takes two integer parameters and returns a value, you can call
2839 that function like so:
2841 result = some_value (10,20)
2843 ** Module gdb.types has been added.
2844 It contains a collection of utilities for working with gdb.Types objects:
2845 get_basic_type, has_field, make_enum_dict.
2847 ** Module gdb.printing has been added.
2848 It contains utilities for writing and registering pretty-printers.
2849 New classes: PrettyPrinter, SubPrettyPrinter,
2850 RegexpCollectionPrettyPrinter.
2851 New function: register_pretty_printer.
2853 ** New commands "info pretty-printers", "enable pretty-printer" and
2854 "disable pretty-printer" have been added.
2856 ** gdb.parameter("directories") is now available.
2858 ** New function gdb.newest_frame returns the newest frame in the
2861 ** The gdb.InferiorThread class has a new "name" attribute. This
2862 holds the thread's name.
2864 ** Python Support for Inferior events.
2865 Python scripts can add observers to be notified of events
2866 occurring in the process being debugged.
2867 The following events are currently supported:
2868 - gdb.events.cont Continue event.
2869 - gdb.events.exited Inferior exited event.
2870 - gdb.events.stop Signal received, and Breakpoint hit events.
2874 ** GDB now puts template parameters in scope when debugging in an
2875 instantiation. For example, if you have:
2877 template<int X> int func (void) { return X; }
2879 then if you step into func<5>, "print X" will show "5". This
2880 feature requires proper debuginfo support from the compiler; it
2881 was added to GCC 4.5.
2883 ** The motion commands "next", "finish", "until", and "advance" now
2884 work better when exceptions are thrown. In particular, GDB will
2885 no longer lose control of the inferior; instead, the GDB will
2886 stop the inferior at the point at which the exception is caught.
2887 This functionality requires a change in the exception handling
2888 code that was introduced in GCC 4.5.
2890 * GDB now follows GCC's rules on accessing volatile objects when
2891 reading or writing target state during expression evaluation.
2892 One notable difference to prior behavior is that "print x = 0"
2893 no longer generates a read of x; the value of the assignment is
2894 now always taken directly from the value being assigned.
2896 * GDB now has some support for using labels in the program's source in
2897 linespecs. For instance, you can use "advance label" to continue
2898 execution to a label.
2900 * GDB now has support for reading and writing a new .gdb_index
2901 section. This section holds a fast index of DWARF debugging
2902 information and can be used to greatly speed up GDB startup and
2903 operation. See the documentation for `save gdb-index' for details.
2905 * The "watch" command now accepts an optional "-location" argument.
2906 When used, this causes GDB to watch the memory referred to by the
2907 expression. Such a watchpoint is never deleted due to it going out
2910 * GDB now supports thread debugging of core dumps on GNU/Linux.
2912 GDB now activates thread debugging using the libthread_db library
2913 when debugging GNU/Linux core dumps, similarly to when debugging
2914 live processes. As a result, when debugging a core dump file, GDB
2915 is now able to display pthread_t ids of threads. For example, "info
2916 threads" shows the same output as when debugging the process when it
2917 was live. In earlier releases, you'd see something like this:
2920 * 1 LWP 6780 main () at main.c:10
2922 While now you see this:
2925 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2927 It is also now possible to inspect TLS variables when debugging core
2930 When debugging a core dump generated on a machine other than the one
2931 used to run GDB, you may need to point GDB at the correct
2932 libthread_db library with the "set libthread-db-search-path"
2933 command. See the user manual for more details on this command.
2935 * When natively debugging programs on PowerPC BookE processors running
2936 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2937 which stop execution of the inferior whenever it executes an instruction
2938 at any address within the specified range. See the "PowerPC Embedded"
2939 section in the user manual for more details.
2941 * New features in the GDB remote stub, GDBserver
2943 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2944 and i686 LynxOS (version 5.x).
2946 ** GDBserver is now supported on Blackfin Linux.
2948 * New native configurations
2950 ia64 HP-UX ia64-*-hpux*
2954 Analog Devices, Inc. Blackfin Processor bfin-*
2956 * Ada task switching is now supported on sparc-elf targets when
2957 debugging a program using the Ravenscar Profile. For more information,
2958 see the "Tasking Support when using the Ravenscar Profile" section
2959 in the GDB user manual.
2961 * Guile support was removed.
2963 * New features in the GNU simulator
2965 ** The --map-info flag lists all known core mappings.
2967 ** CFI flashes may be simulated via the "cfi" device.
2969 *** Changes in GDB 7.2
2971 * Shared library support for remote targets by default
2973 When GDB is configured for a generic, non-OS specific target, like
2974 for example, --target=arm-eabi or one of the many *-*-elf targets,
2975 GDB now queries remote stubs for loaded shared libraries using the
2976 `qXfer:libraries:read' packet. Previously, shared library support
2977 was always disabled for such configurations.
2981 ** Argument Dependent Lookup (ADL)
2983 In C++ ADL lookup directs function search to the namespaces of its
2984 arguments even if the namespace has not been imported.
2994 Here the compiler will search for `foo' in the namespace of 'b'
2995 and find A::foo. GDB now supports this. This construct is commonly
2996 used in the Standard Template Library for operators.
2998 ** Improved User Defined Operator Support
3000 In addition to member operators, GDB now supports lookup of operators
3001 defined in a namespace and imported with a `using' directive, operators
3002 defined in the global scope, operators imported implicitly from an
3003 anonymous namespace, and the ADL operators mentioned in the previous
3005 GDB now also supports proper overload resolution for all the previously
3006 mentioned flavors of operators.
3008 ** static const class members
3010 Printing of static const class members that are initialized in the
3011 class definition has been fixed.
3013 * Windows Thread Information Block access.
3015 On Windows targets, GDB now supports displaying the Windows Thread
3016 Information Block (TIB) structure. This structure is visible either
3017 by using the new command `info w32 thread-information-block' or, by
3018 dereferencing the new convenience variable named `$_tlb', a
3019 thread-specific pointer to the TIB. This feature is also supported
3020 when remote debugging using GDBserver.
3022 * Static tracepoints
3024 Static tracepoints are calls in the user program into a tracing
3025 library. One such library is a port of the LTTng kernel tracer to
3026 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3027 When debugging with GDBserver, GDB now supports combining the GDB
3028 tracepoint machinery with such libraries. For example: the user can
3029 use GDB to probe a static tracepoint marker (a call from the user
3030 program into the tracing library) with the new "strace" command (see
3031 "New commands" below). This creates a "static tracepoint" in the
3032 breakpoint list, that can be manipulated with the same feature set
3033 as fast and regular tracepoints. E.g., collect registers, local and
3034 global variables, collect trace state variables, and define
3035 tracepoint conditions. In addition, the user can collect extra
3036 static tracepoint marker specific data, by collecting the new
3037 $_sdata internal variable. When analyzing the trace buffer, you can
3038 inspect $_sdata like any other variable available to GDB. For more
3039 information, see the "Tracepoints" chapter in GDB user manual. New
3040 remote packets have been defined to support static tracepoints, see
3041 the "New remote packets" section below.
3043 * Better reconstruction of tracepoints after disconnected tracing
3045 GDB will attempt to download the original source form of tracepoint
3046 definitions when starting a trace run, and then will upload these
3047 upon reconnection to the target, resulting in a more accurate
3048 reconstruction of the tracepoints that are in use on the target.
3052 You can now exercise direct control over the ways that GDB can
3053 affect your program. For instance, you can disallow the setting of
3054 breakpoints, so that the program can run continuously (assuming
3055 non-stop mode). In addition, the "observer" variable is available
3056 to switch all of the different controls; in observer mode, GDB
3057 cannot affect the target's behavior at all, which is useful for
3058 tasks like diagnosing live systems in the field.
3060 * The new convenience variable $_thread holds the number of the
3063 * New remote packets
3067 Return the address of the Windows Thread Information Block of a given thread.
3071 In response to several of the tracepoint packets, the target may now
3072 also respond with a number of intermediate `qRelocInsn' request
3073 packets before the final result packet, to have GDB handle
3074 relocating an instruction to execute at a different address. This
3075 is particularly useful for stubs that support fast tracepoints. GDB
3076 reports support for this feature in the qSupported packet.
3080 List static tracepoint markers in the target program.
3084 List static tracepoint markers at a given address in the target
3087 qXfer:statictrace:read
3089 Read the static trace data collected (by a `collect $_sdata'
3090 tracepoint action). The remote stub reports support for this packet
3091 to gdb's qSupported query.
3095 Send the current settings of GDB's permission flags.
3099 Send part of the source (textual) form of a tracepoint definition,
3100 which includes location, conditional, and action list.
3102 * The source command now accepts a -s option to force searching for the
3103 script in the source search path even if the script name specifies
3106 * New features in the GDB remote stub, GDBserver
3108 - GDBserver now support tracepoints (including fast tracepoints, and
3109 static tracepoints). The feature is currently supported by the
3110 i386-linux and amd64-linux builds. See the "Tracepoints support
3111 in gdbserver" section in the manual for more information.
3113 GDBserver JIT compiles the tracepoint's conditional agent
3114 expression bytecode into native code whenever possible for low
3115 overhead dynamic tracepoints conditionals. For such tracepoints,
3116 an expression that examines program state is evaluated when the
3117 tracepoint is reached, in order to determine whether to capture
3118 trace data. If the condition is simple and false, processing the
3119 tracepoint finishes very quickly and no data is gathered.
3121 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3122 for static tracepoints support.
3124 - GDBserver now supports x86_64 Windows 64-bit debugging.
3126 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3127 it understands register description.
3129 * The --batch flag now disables pagination and queries.
3131 * X86 general purpose registers
3133 GDB now supports reading/writing byte, word and double-word x86
3134 general purpose registers directly. This means you can use, say,
3135 $ah or $ax to refer, respectively, to the byte register AH and
3136 16-bit word register AX that are actually portions of the 32-bit
3137 register EAX or 64-bit register RAX.
3139 * The `commands' command now accepts a range of breakpoints to modify.
3140 A plain `commands' following a command that creates multiple
3141 breakpoints affects all the breakpoints set by that command. This
3142 applies to breakpoints set by `rbreak', and also applies when a
3143 single `break' command creates multiple breakpoints (e.g.,
3144 breakpoints on overloaded c++ functions).
3146 * The `rbreak' command now accepts a filename specification as part of
3147 its argument, limiting the functions selected by the regex to those
3148 in the specified file.
3150 * Support for remote debugging Windows and SymbianOS shared libraries
3151 from Unix hosts has been improved. Non Windows GDB builds now can
3152 understand target reported file names that follow MS-DOS based file
3153 system semantics, such as file names that include drive letters and
3154 use the backslash character as directory separator. This makes it
3155 possible to transparently use the "set sysroot" and "set
3156 solib-search-path" on Unix hosts to point as host copies of the
3157 target's shared libraries. See the new command "set
3158 target-file-system-kind" described below, and the "Commands to
3159 specify files" section in the user manual for more information.
3163 eval template, expressions...
3164 Convert the values of one or more expressions under the control
3165 of the string template to a command line, and call it.
3167 set target-file-system-kind unix|dos-based|auto
3168 show target-file-system-kind
3169 Set or show the assumed file system kind for target reported file
3172 save breakpoints <filename>
3173 Save all current breakpoint definitions to a file suitable for use
3174 in a later debugging session. To read the saved breakpoint
3175 definitions, use the `source' command.
3177 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3180 info static-tracepoint-markers
3181 Display information about static tracepoint markers in the target.
3183 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3184 Define a static tracepoint by probing a marker at the given
3185 function, line, address, or marker ID.
3189 Enable and disable observer mode.
3191 set may-write-registers on|off
3192 set may-write-memory on|off
3193 set may-insert-breakpoints on|off
3194 set may-insert-tracepoints on|off
3195 set may-insert-fast-tracepoints on|off
3196 set may-interrupt on|off
3197 Set individual permissions for GDB effects on the target. Note that
3198 some of these settings can have undesirable or surprising
3199 consequences, particularly when changed in the middle of a session.
3200 For instance, disabling the writing of memory can prevent
3201 breakpoints from being inserted, cause single-stepping to fail, or
3202 even crash your program, if you disable after breakpoints have been
3203 inserted. However, GDB should not crash.
3205 set record memory-query on|off
3206 show record memory-query
3207 Control whether to stop the inferior if memory changes caused
3208 by an instruction cannot be recorded.
3213 The disassemble command now supports "start,+length" form of two arguments.
3217 ** GDB now provides a new directory location, called the python directory,
3218 where Python scripts written for GDB can be installed. The location
3219 of that directory is <data-directory>/python, where <data-directory>
3220 is the GDB data directory. For more details, see section `Scripting
3221 GDB using Python' in the manual.
3223 ** The GDB Python API now has access to breakpoints, symbols, symbol
3224 tables, program spaces, inferiors, threads and frame's code blocks.
3225 Additionally, GDB Parameters can now be created from the API, and
3226 manipulated via set/show in the CLI.
3228 ** New functions gdb.target_charset, gdb.target_wide_charset,
3229 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3231 ** New exception gdb.GdbError.
3233 ** Pretty-printers are now also looked up in the current program space.
3235 ** Pretty-printers can now be individually enabled and disabled.
3237 ** GDB now looks for names of Python scripts to auto-load in a
3238 special section named `.debug_gdb_scripts', in addition to looking
3239 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3241 * Tracepoint actions were unified with breakpoint commands. In particular,
3242 there are no longer differences in "info break" output for breakpoints and
3243 tracepoints and the "commands" command can be used for both tracepoints and
3244 regular breakpoints.
3248 ARM Symbian arm*-*-symbianelf*
3250 * D language support.
3251 GDB now supports debugging programs written in the D programming
3254 * GDB now supports the extended ptrace interface for PowerPC which is
3255 available since Linux kernel version 2.6.34. This automatically enables
3256 any hardware breakpoints and additional hardware watchpoints available in
3257 the processor. The old ptrace interface exposes just one hardware
3258 watchpoint and no hardware breakpoints.
3260 * GDB is now able to use the Data Value Compare (DVC) register available on
3261 embedded PowerPC processors to implement in hardware simple watchpoint
3262 conditions of the form:
3264 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3266 This works in native GDB running on Linux kernels with the extended ptrace
3267 interface mentioned above.
3269 *** Changes in GDB 7.1
3273 ** Namespace Support
3275 GDB now supports importing of namespaces in C++. This enables the
3276 user to inspect variables from imported namespaces. Support for
3277 namepace aliasing has also been added. So, if a namespace is
3278 aliased in the current scope (e.g. namepace C=A; ) the user can
3279 print variables using the alias (e.g. (gdb) print C::x).
3283 All known bugs relating to the printing of virtual base class were
3284 fixed. It is now possible to call overloaded static methods using a
3289 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3290 and reinterpret_cast<> are now handled by the C++ expression parser.
3294 Xilinx MicroBlaze microblaze-*-*
3299 Xilinx MicroBlaze microblaze
3302 * Multi-program debugging.
3304 GDB now has support for multi-program (a.k.a. multi-executable or
3305 multi-exec) debugging. This allows for debugging multiple inferiors
3306 simultaneously each running a different program under the same GDB
3307 session. See "Debugging Multiple Inferiors and Programs" in the
3308 manual for more information. This implied some user visible changes
3309 in the multi-inferior support. For example, "info inferiors" now
3310 lists inferiors that are not running yet or that have exited
3311 already. See also "New commands" and "New options" below.
3313 * New tracing features
3315 GDB's tracepoint facility now includes several new features:
3317 ** Trace state variables
3319 GDB tracepoints now include support for trace state variables, which
3320 are variables managed by the target agent during a tracing
3321 experiment. They are useful for tracepoints that trigger each
3322 other, so for instance one tracepoint can count hits in a variable,
3323 and then a second tracepoint has a condition that is true when the
3324 count reaches a particular value. Trace state variables share the
3325 $-syntax of GDB convenience variables, and can appear in both
3326 tracepoint actions and condition expressions. Use the "tvariable"
3327 command to create, and "info tvariables" to view; see "Trace State
3328 Variables" in the manual for more detail.
3332 GDB now includes an option for defining fast tracepoints, which
3333 targets may implement more efficiently, such as by installing a jump
3334 into the target agent rather than a trap instruction. The resulting
3335 speedup can be by two orders of magnitude or more, although the
3336 tradeoff is that some program locations on some target architectures
3337 might not allow fast tracepoint installation, for instance if the
3338 instruction to be replaced is shorter than the jump. To request a
3339 fast tracepoint, use the "ftrace" command, with syntax identical to
3340 the regular trace command.
3342 ** Disconnected tracing
3344 It is now possible to detach GDB from the target while it is running
3345 a trace experiment, then reconnect later to see how the experiment
3346 is going. In addition, a new variable disconnected-tracing lets you
3347 tell the target agent whether to continue running a trace if the
3348 connection is lost unexpectedly.
3352 GDB now has the ability to save the trace buffer into a file, and
3353 then use that file as a target, similarly to you can do with
3354 corefiles. You can select trace frames, print data that was
3355 collected in them, and use tstatus to display the state of the
3356 tracing run at the moment that it was saved. To create a trace
3357 file, use "tsave <filename>", and to use it, do "target tfile
3360 ** Circular trace buffer
3362 You can ask the target agent to handle the trace buffer as a
3363 circular buffer, discarding the oldest trace frames to make room for
3364 newer ones, by setting circular-trace-buffer to on. This feature may
3365 not be available for all target agents.
3370 The disassemble command, when invoked with two arguments, now requires
3371 the arguments to be comma-separated.
3374 The info variables command now displays variable definitions. Files
3375 which only declare a variable are not shown.
3378 The source command is now capable of sourcing Python scripts.
3379 This feature is dependent on the debugger being build with Python
3382 Related to this enhancement is also the introduction of a new command
3383 "set script-extension" (see below).
3385 * New commands (for set/show, see "New options" below)
3387 record save [<FILENAME>]
3388 Save a file (in core file format) containing the process record
3389 execution log for replay debugging at a later time.
3391 record restore <FILENAME>
3392 Restore the process record execution log that was saved at an
3393 earlier time, for replay debugging.
3395 add-inferior [-copies <N>] [-exec <FILENAME>]
3398 clone-inferior [-copies <N>] [ID]
3399 Make a new inferior ready to execute the same program another
3400 inferior has loaded.
3405 maint info program-spaces
3406 List the program spaces loaded into GDB.
3408 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3409 show remote interrupt-sequence
3410 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3411 as the sequence to the remote target in order to interrupt the execution.
3412 Ctrl-C is a default. Some system prefers BREAK which is high level of
3413 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3414 Magic SysRq g. It is BREAK signal and character 'g'.
3416 set remote interrupt-on-connect [on | off]
3417 show remote interrupt-on-connect
3418 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3419 remote target when gdb connects to it. This is needed when you debug
3422 set remotebreak [on | off]
3424 Deprecated. Use "set/show remote interrupt-sequence" instead.
3426 tvariable $NAME [ = EXP ]
3427 Create or modify a trace state variable.
3430 List trace state variables and their values.
3432 delete tvariable $NAME ...
3433 Delete one or more trace state variables.
3436 Evaluate the given expressions without collecting anything into the
3437 trace buffer. (Valid in tracepoint actions only.)
3439 ftrace FN / FILE:LINE / *ADDR
3440 Define a fast tracepoint at the given function, line, or address.
3442 * New expression syntax
3444 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3445 GDB now parses 0b101010 identically with 42.
3449 set follow-exec-mode new|same
3450 show follow-exec-mode
3451 Control whether GDB reuses the same inferior across an exec call or
3452 creates a new one. This is useful to be able to restart the old
3453 executable after the inferior having done an exec call.
3455 set default-collect EXPR, ...
3456 show default-collect
3457 Define a list of expressions to be collected at each tracepoint.
3458 This is a useful way to ensure essential items are not overlooked,
3459 such as registers or a critical global variable.
3461 set disconnected-tracing
3462 show disconnected-tracing
3463 If set to 1, the target is instructed to continue tracing if it
3464 loses its connection to GDB. If 0, the target is to stop tracing
3467 set circular-trace-buffer
3468 show circular-trace-buffer
3469 If set to on, the target is instructed to use a circular trace buffer
3470 and discard the oldest trace frames instead of stopping the trace due
3471 to a full trace buffer. If set to off, the trace stops when the buffer
3472 fills up. Some targets may not support this.
3474 set script-extension off|soft|strict
3475 show script-extension
3476 If set to "off", the debugger does not perform any script language
3477 recognition, and all sourced files are assumed to be GDB scripts.
3478 If set to "soft" (the default), files are sourced according to
3479 filename extension, falling back to GDB scripts if the first
3481 If set to "strict", files are sourced according to filename extension.
3483 set ada trust-PAD-over-XVS on|off
3484 show ada trust-PAD-over-XVS
3485 If off, activate a workaround against a bug in the debugging information
3486 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3487 the GCC sources for more information about the GNAT encoding and
3488 PAD types in particular). It is always safe to set this option to
3489 off, but this introduces a slight performance penalty. The default
3492 * Python API Improvements
3494 ** GDB provides the new class gdb.LazyString. This is useful in
3495 some pretty-printing cases. The new method gdb.Value.lazy_string
3496 provides a simple way to create objects of this type.
3498 ** The fields returned by gdb.Type.fields now have an
3499 `is_base_class' attribute.
3501 ** The new method gdb.Type.range returns the range of an array type.
3503 ** The new method gdb.parse_and_eval can be used to parse and
3504 evaluate an expression.
3506 * New remote packets
3509 Define a trace state variable.
3512 Get the current value of a trace state variable.
3515 Set desired tracing behavior upon disconnection.
3518 Set the trace buffer to be linear or circular.
3521 Get data about the tracepoints currently in use.
3525 Process record now works correctly with hardware watchpoints.
3527 Multiple bug fixes have been made to the mips-irix port, making it
3528 much more reliable. In particular:
3529 - Debugging threaded applications is now possible again. Previously,
3530 GDB would hang while starting the program, or while waiting for
3531 the program to stop at a breakpoint.
3532 - Attaching to a running process no longer hangs.
3533 - An error occurring while loading a core file has been fixed.
3534 - Changing the value of the PC register now works again. This fixes
3535 problems observed when using the "jump" command, or when calling
3536 a function from GDB, or even when assigning a new value to $pc.
3537 - With the "finish" and "return" commands, the return value for functions
3538 returning a small array is now correctly printed.
3539 - It is now possible to break on shared library code which gets executed
3540 during a shared library init phase (code executed while executing
3541 their .init section). Previously, the breakpoint would have no effect.
3542 - GDB is now able to backtrace through the signal handler for
3543 non-threaded programs.
3545 PIE (Position Independent Executable) programs debugging is now supported.
3546 This includes debugging execution of PIC (Position Independent Code) shared
3547 libraries although for that, it should be possible to run such libraries as an
3550 *** Changes in GDB 7.0
3552 * GDB now has an interface for JIT compilation. Applications that
3553 dynamically generate code can create symbol files in memory and register
3554 them with GDB. For users, the feature should work transparently, and
3555 for JIT developers, the interface is documented in the GDB manual in the
3556 "JIT Compilation Interface" chapter.
3558 * Tracepoints may now be conditional. The syntax is as for
3559 breakpoints; either an "if" clause appended to the "trace" command,
3560 or the "condition" command is available. GDB sends the condition to
3561 the target for evaluation using the same bytecode format as is used
3562 for tracepoint actions.
3564 * The disassemble command now supports: an optional /r modifier, print the
3565 raw instructions in hex as well as in symbolic form, and an optional /m
3566 modifier to print mixed source+assembly.
3568 * Process record and replay
3570 In a architecture environment that supports ``process record and
3571 replay'', ``process record and replay'' target can record a log of
3572 the process execution, and replay it with both forward and reverse
3575 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3576 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3577 set execution-direction {forward|reverse}, for targets that support
3580 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3581 feature is available with a native GDB running on kernel version
3584 * GDB now has support for multi-byte and wide character sets on the
3585 target. Strings whose character type is wchar_t, char16_t, or
3586 char32_t are now correctly printed. GDB supports wide- and unicode-
3587 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3588 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3589 `printf'. This feature requires iconv to work properly; if your
3590 system does not have a working iconv, GDB can use GNU libiconv. See
3591 the installation instructions for more information.
3593 * GDB now supports automatic retrieval of shared library files from
3594 remote targets. To use this feature, specify a system root that begins
3595 with the `remote:' prefix, either via the `set sysroot' command or via
3596 the `--with-sysroot' configure-time option.
3598 * "info sharedlibrary" now takes an optional regex of libraries to show,
3599 and it now reports if a shared library has no debugging information.
3601 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3602 now complete on file names.
3604 * When completing in expressions, gdb will attempt to limit
3605 completions to allowable structure or union fields, where appropriate.
3606 For instance, consider:
3608 # struct example { int f1; double f2; };
3609 # struct example variable;
3612 If the user types TAB at the end of this command line, the available
3613 completions will be "f1" and "f2".
3615 * Inlined functions are now supported. They show up in backtraces, and
3616 the "step", "next", and "finish" commands handle them automatically.
3618 * GDB now supports the token-splicing (##) and stringification (#)
3619 operators when expanding macros. It also supports variable-arity
3622 * GDB now supports inspecting extra signal information, exported by
3623 the new $_siginfo convenience variable. The feature is currently
3624 implemented on linux ARM, i386 and amd64.
3626 * GDB can now display the VFP floating point registers and NEON vector
3627 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3628 can provide these registers (requires Linux 2.6.30 or later). Remote
3629 and simulator targets may also provide them.
3631 * New remote packets
3634 Search memory for a sequence of bytes.
3637 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3638 operation over reliable transport links. Use of this packet is
3639 controlled by the `set remote noack-packet' command.
3642 Kill the process with the specified process ID. Use this in preference
3643 to `k' when multiprocess protocol extensions are supported.
3646 Obtains additional operating system information
3650 Read or write additional signal information.
3652 * Removed remote protocol undocumented extension
3654 An undocumented extension to the remote protocol's `S' stop reply
3655 packet that permited the stub to pass a process id was removed.
3656 Remote servers should use the `T' stop reply packet instead.
3658 * GDB now supports multiple function calling conventions according to the
3659 DWARF-2 DW_AT_calling_convention function attribute.
3661 * The SH target utilizes the aforementioned change to distinguish between gcc
3662 and Renesas calling convention. It also adds the new CLI commands
3663 `set/show sh calling-convention'.
3665 * GDB can now read compressed debug sections, as produced by GNU gold
3666 with the --compress-debug-sections=zlib flag.
3668 * 64-bit core files are now supported on AIX.
3670 * Thread switching is now supported on Tru64.
3672 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3673 which will be allocated using malloc later in program execution.
3675 * The qXfer:libraries:read remote procotol packet now allows passing a
3676 list of section offsets.
3678 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3679 conditions handling signals delivered during attach or thread creation
3680 have also been fixed.
3682 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3683 From the user's standpoint, all unqualified instances of True and False
3684 are treated as the standard definitions, regardless of context.
3686 * GDB now parses C++ symbol and type names more flexibly. For
3689 template<typename T> class C { };
3692 GDB will now correctly handle all of:
3694 ptype C<char const *>
3695 ptype C<char const*>
3696 ptype C<const char *>
3697 ptype C<const char*>
3699 * New features in the GDB remote stub, gdbserver
3701 - The "--wrapper" command-line argument tells gdbserver to use a
3702 wrapper program to launch programs for debugging.
3704 - On PowerPC and S/390 targets, it is now possible to use a single
3705 gdbserver executable to debug both 32-bit and 64-bit programs.
3706 (This requires gdbserver itself to be built as a 64-bit executable.)
3708 - gdbserver uses the new noack protocol mode for TCP connections to
3709 reduce communications latency, if also supported and enabled in GDB.
3711 - Support for the sparc64-linux-gnu target is now included in
3714 - The amd64-linux build of gdbserver now supports debugging both
3715 32-bit and 64-bit programs.
3717 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3718 now support hardware watchpoints, and will use them automatically
3723 GDB now has support for scripting using Python. Whether this is
3724 available is determined at configure time.
3726 New GDB commands can now be written in Python.
3728 * Ada tasking support
3730 Ada tasks can now be inspected in GDB. The following commands have
3734 Print the list of Ada tasks.
3736 Print detailed information about task number N.
3738 Print the task number of the current task.
3740 Switch the context of debugging to task number N.
3742 * Support for user-defined prefixed commands. The "define" command can
3743 add new commands to existing prefixes, e.g. "target".
3745 * Multi-inferior, multi-process debugging.
3747 GDB now has generalized support for multi-inferior debugging. See
3748 "Debugging Multiple Inferiors" in the manual for more information.
3749 Although availability still depends on target support, the command
3750 set is more uniform now. The GNU/Linux specific multi-forks support
3751 has been migrated to this new framework. This implied some user
3752 visible changes; see "New commands" and also "Removed commands"
3755 * Target descriptions can now describe the target OS ABI. See the
3756 "Target Description Format" section in the user manual for more
3759 * Target descriptions can now describe "compatible" architectures
3760 to indicate that the target can execute applications for a different
3761 architecture in addition to those for the main target architecture.
3762 See the "Target Description Format" section in the user manual for
3765 * Multi-architecture debugging.
3767 GDB now includes general supports for debugging applications on
3768 hybrid systems that use more than one single processor architecture
3769 at the same time. Each such hybrid architecture still requires
3770 specific support to be added. The only hybrid architecture supported
3771 in this version of GDB is the Cell Broadband Engine.
3773 * GDB now supports integrated debugging of Cell/B.E. applications that
3774 use both the PPU and SPU architectures. To enable support for hybrid
3775 Cell/B.E. debugging, you need to configure GDB to support both the
3776 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3777 --enable-targets configure option.
3779 * Non-stop mode debugging.
3781 For some targets, GDB now supports an optional mode of operation in
3782 which you can examine stopped threads while other threads continue
3783 to execute freely. This is referred to as non-stop mode, with the
3784 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3785 section in the user manual for more information.
3787 To be able to support remote non-stop debugging, a remote stub needs
3788 to implement the non-stop mode remote protocol extensions, as
3789 described in the "Remote Non-Stop" section of the user manual. The
3790 GDB remote stub, gdbserver, has been adjusted to support these
3791 extensions on linux targets.
3793 * New commands (for set/show, see "New options" below)
3795 catch syscall [NAME(S) | NUMBER(S)]
3796 Catch system calls. Arguments, which should be names of system
3797 calls or their numbers, mean catch only those syscalls. Without
3798 arguments, every syscall will be caught. When the inferior issues
3799 any of the specified syscalls, GDB will stop and announce the system
3800 call, both when it is called and when its call returns. This
3801 feature is currently available with a native GDB running on the
3802 Linux Kernel, under the following architectures: x86, x86_64,
3803 PowerPC and PowerPC64.
3805 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3807 Search memory for a sequence of bytes.
3809 maint set python print-stack
3810 maint show python print-stack
3811 Show a stack trace when an error is encountered in a Python script.
3814 Invoke CODE by passing it to the Python interpreter.
3819 These allow macros to be defined, undefined, and listed
3823 Show operating system information about processes.
3826 List the inferiors currently under GDB's control.
3829 Switch focus to inferior number NUM.
3832 Detach from inferior number NUM.
3835 Kill inferior number NUM.
3839 set spu stop-on-load
3840 show spu stop-on-load
3841 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3843 set spu auto-flush-cache
3844 show spu auto-flush-cache
3845 Control whether to automatically flush the software-managed cache
3846 during Cell/B.E. debugging.
3848 set sh calling-convention
3849 show sh calling-convention
3850 Control the calling convention used when calling SH target functions.
3853 show debug timestamp
3854 Control display of timestamps with GDB debugging output.
3856 set disassemble-next-line
3857 show disassemble-next-line
3858 Control display of disassembled source lines or instructions when
3861 set remote noack-packet
3862 show remote noack-packet
3863 Set/show the use of remote protocol QStartNoAckMode packet. See above
3864 under "New remote packets."
3866 set remote query-attached-packet
3867 show remote query-attached-packet
3868 Control use of remote protocol `qAttached' (query-attached) packet.
3870 set remote read-siginfo-object
3871 show remote read-siginfo-object
3872 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3875 set remote write-siginfo-object
3876 show remote write-siginfo-object
3877 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3880 set remote reverse-continue
3881 show remote reverse-continue
3882 Control use of remote protocol 'bc' (reverse-continue) packet.
3884 set remote reverse-step
3885 show remote reverse-step
3886 Control use of remote protocol 'bs' (reverse-step) packet.
3888 set displaced-stepping
3889 show displaced-stepping
3890 Control displaced stepping mode. Displaced stepping is a way to
3891 single-step over breakpoints without removing them from the debuggee.
3892 Also known as "out-of-line single-stepping".
3895 show debug displaced
3896 Control display of debugging info for displaced stepping.
3898 maint set internal-error
3899 maint show internal-error
3900 Control what GDB does when an internal error is detected.
3902 maint set internal-warning
3903 maint show internal-warning
3904 Control what GDB does when an internal warning is detected.
3909 Use a wrapper program to launch programs for debugging.
3911 set multiple-symbols (all|ask|cancel)
3912 show multiple-symbols
3913 The value of this variable can be changed to adjust the debugger behavior
3914 when an expression or a breakpoint location contains an ambiguous symbol
3915 name (an overloaded function name, for instance).
3917 set breakpoint always-inserted
3918 show breakpoint always-inserted
3919 Keep breakpoints always inserted in the target, as opposed to inserting
3920 them when resuming the target, and removing them when the target stops.
3921 This option can improve debugger performance on slow remote targets.
3923 set arm fallback-mode (arm|thumb|auto)
3924 show arm fallback-mode
3925 set arm force-mode (arm|thumb|auto)
3927 These commands control how ARM GDB determines whether instructions
3928 are ARM or Thumb. The default for both settings is auto, which uses
3929 the current CPSR value for instructions without symbols; previous
3930 versions of GDB behaved as if "set arm fallback-mode arm".
3932 set disable-randomization
3933 show disable-randomization
3934 Standalone programs run with the virtual address space randomization enabled
3935 by default on some platforms. This option keeps the addresses stable across
3936 multiple debugging sessions.
3940 Control whether other threads are stopped or not when some thread hits
3945 Requests that asynchronous execution is enabled in the target, if available.
3946 In this case, it's possible to resume target in the background, and interact
3947 with GDB while the target is running. "show target-async" displays the
3948 current state of asynchronous execution of the target.
3950 set target-wide-charset
3951 show target-wide-charset
3952 The target-wide-charset is the name of the character set that GDB
3953 uses when printing characters whose type is wchar_t.
3955 set tcp auto-retry (on|off)
3957 set tcp connect-timeout
3958 show tcp connect-timeout
3959 These commands allow GDB to retry failed TCP connections to a remote stub
3960 with a specified timeout period; this is useful if the stub is launched
3961 in parallel with GDB but may not be ready to accept connections immediately.
3963 set libthread-db-search-path
3964 show libthread-db-search-path
3965 Control list of directories which GDB will search for appropriate
3968 set schedule-multiple (on|off)
3969 show schedule-multiple
3970 Allow GDB to resume all threads of all processes or only threads of
3971 the current process.
3975 Use more aggressive caching for accesses to the stack. This improves
3976 performance of remote debugging (particularly backtraces) without
3977 affecting correctness.
3979 set interactive-mode (on|off|auto)
3980 show interactive-mode
3981 Control whether GDB runs in interactive mode (on) or not (off).
3982 When in interactive mode, GDB waits for the user to answer all
3983 queries. Otherwise, GDB does not wait and assumes the default
3984 answer. When set to auto (the default), GDB determines which
3985 mode to use based on the stdin settings.
3990 For program forks, this is replaced by the new more generic `info
3991 inferiors' command. To list checkpoints, you can still use the
3992 `info checkpoints' command, which was an alias for the `info forks'
3996 Replaced by the new `inferior' command. To switch between
3997 checkpoints, you can still use the `restart' command, which was an
3998 alias for the `fork' command.
4001 This is removed, since some targets don't have a notion of
4002 processes. To switch between processes, you can still use the
4003 `inferior' command using GDB's own inferior number.
4006 For program forks, this is replaced by the new more generic `kill
4007 inferior' command. To delete a checkpoint, you can still use the
4008 `delete checkpoint' command, which was an alias for the `delete
4012 For program forks, this is replaced by the new more generic `detach
4013 inferior' command. To detach a checkpoint, you can still use the
4014 `detach checkpoint' command, which was an alias for the `detach
4017 * New native configurations
4019 x86/x86_64 Darwin i[34567]86-*-darwin*
4021 x86_64 MinGW x86_64-*-mingw*
4025 Lattice Mico32 lm32-*
4026 x86 DICOS i[34567]86-*-dicos*
4027 x86_64 DICOS x86_64-*-dicos*
4030 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4031 (mingw32ce) debugging.
4037 These commands were actually not implemented on any target.
4039 *** Changes in GDB 6.8
4041 * New native configurations
4043 NetBSD/hppa hppa*-*netbsd*
4044 Xtensa GNU/Linux xtensa*-*-linux*
4048 NetBSD/hppa hppa*-*-netbsd*
4049 Xtensa GNU/Lunux xtensa*-*-linux*
4051 * Change in command line behavior -- corefiles vs. process ids.
4053 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4054 attaching to process NUMBER fails, GDB no longer attempts to open a
4055 core file named NUMBER. Attaching to a program using the -c option
4056 is no longer supported. Instead, use the '-p' or '--pid' options.
4058 * GDB can now be built as a native debugger for debugging Windows x86
4059 (mingw32) Portable Executable (PE) programs.
4061 * Pending breakpoints no longer change their number when their address
4064 * GDB now supports breakpoints with multiple locations,
4065 including breakpoints on C++ constructors, inside C++ templates,
4066 and in inlined functions.
4068 * GDB's ability to debug optimized code has been improved. GDB more
4069 accurately identifies function bodies and lexical blocks that occupy
4070 more than one contiguous range of addresses.
4072 * Target descriptions can now describe registers for PowerPC.
4074 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4075 registers on PowerPC targets.
4077 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4078 targets even when the libthread_db library is not available.
4080 * The GDB remote stub, gdbserver, now supports the new file transfer
4081 commands (remote put, remote get, and remote delete).
4083 * The GDB remote stub, gdbserver, now supports run and attach in
4084 extended-remote mode.
4086 * hppa*64*-*-hpux11* target broken
4087 The debugger is unable to start a program and fails with the following
4088 error: "Error trying to get information about dynamic linker".
4089 The gdb-6.7 release is also affected.
4091 * GDB now supports the --enable-targets= configure option to allow
4092 building a single GDB executable that supports multiple remote
4093 target architectures.
4095 * GDB now supports debugging C and C++ programs which use the
4096 Decimal Floating Point extension. In addition, the PowerPC target
4097 now has a set of pseudo-registers to inspect decimal float values
4098 stored in two consecutive float registers.
4100 * The -break-insert MI command can optionally create pending
4103 * Improved support for debugging Ada
4104 Many improvements to the Ada language support have been made. These
4106 - Better support for Ada2005 interface types
4107 - Improved handling of arrays and slices in general
4108 - Better support for Taft-amendment types
4109 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4111 - Improved command completion in Ada
4114 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4119 set print frame-arguments (all|scalars|none)
4120 show print frame-arguments
4121 The value of this variable can be changed to control which argument
4122 values should be printed by the debugger when displaying a frame.
4127 Transfer files to and from a remote target, and delete remote files.
4134 Transfer files to and from a remote target, and delete remote files.
4136 * New remote packets
4143 Open, close, read, write, and delete files on the remote system.
4146 Attach to an existing process on the remote system, in extended-remote
4150 Run a new process on the remote system, in extended-remote mode.
4152 *** Changes in GDB 6.7
4154 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4155 bfd, libiberty and opcodes, as revealed by static analysis donated by
4156 Coverity, Inc. (http://scan.coverity.com).
4158 * When looking up multiply-defined global symbols, GDB will now prefer the
4159 symbol definition in the current shared library if it was built using the
4160 -Bsymbolic linker option.
4162 * When the Text User Interface (TUI) is not configured, GDB will now
4163 recognize the -tui command-line option and print a message that the TUI
4166 * The GDB remote stub, gdbserver, now has lower overhead for high
4167 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4169 * GDB for MIPS targets now autodetects whether a remote target provides
4170 32-bit or 64-bit register values.
4172 * Support for C++ member pointers has been improved.
4174 * GDB now understands XML target descriptions, which specify the
4175 target's overall architecture. GDB can read a description from
4176 a local file or over the remote serial protocol.
4178 * Vectors of single-byte data use a new integer type which is not
4179 automatically displayed as character or string data.
4181 * The /s format now works with the print command. It displays
4182 arrays of single-byte integers and pointers to single-byte integers
4185 * Target descriptions can now describe target-specific registers,
4186 for architectures which have implemented the support (currently
4187 only ARM, M68K, and MIPS).
4189 * GDB and the GDB remote stub, gdbserver, now support the XScale
4192 * The GDB remote stub, gdbserver, has been updated to support
4193 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4194 has been rewritten to use the standard GDB remote protocol.
4196 * GDB can now step into C++ functions which are called through thunks.
4198 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4200 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4201 layout. It also supports a TextSeg= and DataSeg= response when only
4202 segment base addresses (rather than offsets) are available.
4204 * The /i format now outputs any trailing branch delay slot instructions
4205 immediately following the last instruction within the count specified.
4207 * The GDB remote protocol "T" stop reply packet now supports a
4208 "library" response. Combined with the new "qXfer:libraries:read"
4209 packet, this response allows GDB to debug shared libraries on targets
4210 where the operating system manages the list of loaded libraries (e.g.
4211 Windows and SymbianOS).
4213 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4214 (DLLs) on Windows and Windows CE targets.
4216 * GDB now supports a faster verification that a .debug file matches its binary
4217 according to its build-id signature, if the signature is present.
4223 Enable or disable hardware flow control (RTS/CTS) on the serial port
4224 when debugging using remote targets.
4226 set mem inaccessible-by-default
4227 show mem inaccessible-by-default
4228 If the target supplies a memory map, for instance via the remote
4229 protocol's "qXfer:memory-map:read" packet, setting this variable
4230 prevents GDB from accessing memory outside the memory map. This
4231 is useful for targets with memory mapped registers or which react
4232 badly to accesses of unmapped address space.
4234 set breakpoint auto-hw
4235 show breakpoint auto-hw
4236 If the target supplies a memory map, for instance via the remote
4237 protocol's "qXfer:memory-map:read" packet, setting this variable
4238 lets GDB use hardware breakpoints automatically for memory regions
4239 where it can not use software breakpoints. This covers both the
4240 "break" command and internal breakpoints used for other commands
4241 including "next" and "finish".
4244 catch exception unhandled
4245 Stop the program execution when Ada exceptions are raised.
4248 Stop the program execution when an Ada assertion failed.
4252 Set an alternate system root for target files. This is a more
4253 general version of "set solib-absolute-prefix", which is now
4254 an alias to "set sysroot".
4257 Provide extended SPU facility status information. This set of
4258 commands is available only when debugging the Cell/B.E. SPU
4261 * New native configurations
4263 OpenBSD/sh sh*-*openbsd*
4266 unset tdesc filename
4268 Use the specified local file as an XML target description, and do
4269 not query the target for its built-in description.
4273 OpenBSD/sh sh*-*-openbsd*
4274 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4275 Toshiba Media Processor mep-elf
4277 * New remote packets
4280 Ignore the specified signals; pass them directly to the debugged program
4281 without stopping other threads or reporting them to GDB.
4283 qXfer:features:read:
4284 Read an XML target description from the target, which describes its
4289 Read or write contents of an spufs file on the target system. These
4290 packets are available only on the Cell/B.E. SPU architecture.
4292 qXfer:libraries:read:
4293 Report the loaded shared libraries. Combined with new "T" packet
4294 response, this packet allows GDB to debug shared libraries on
4295 targets where the operating system manages the list of loaded
4296 libraries (e.g. Windows and SymbianOS).
4300 Support for these obsolete configurations has been removed.
4308 i[34567]86-*-lynxos*
4309 i[34567]86-*-netware*
4310 i[34567]86-*-sco3.2v5*
4311 i[34567]86-*-sco3.2v4*
4313 i[34567]86-*-sysv4.2*
4316 i[34567]86-*-unixware2*
4317 i[34567]86-*-unixware*
4326 * Other removed features
4333 Various m68k-only ROM monitors.
4340 Various Renesas ROM monitors and debugging interfaces for SH and
4345 Support for a Macraigor serial interface to on-chip debugging.
4346 GDB does not directly support the newer parallel or USB
4351 A debug information format. The predecessor to DWARF 2 and
4352 DWARF 3, which are still supported.
4354 Support for the HP aCC compiler on HP-UX/PA-RISC
4356 SOM-encapsulated symbolic debugging information, automatic
4357 invocation of pxdb, and the aCC custom C++ ABI. This does not
4358 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4359 with aCC can still be debugged on an assembly level.
4361 MIPS ".pdr" sections
4363 A MIPS-specific format used to describe stack frame layout
4364 in debugging information.
4368 GDB could work with an older version of Guile to debug
4369 the interpreter and Scheme programs running in it.
4371 set mips stack-arg-size
4372 set mips saved-gpreg-size
4374 Use "set mips abi" to control parameter passing for MIPS.
4376 *** Changes in GDB 6.6
4381 Cell Broadband Engine SPU spu-elf
4383 * GDB can now be configured as a cross-debugger targeting native Windows
4384 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4385 running on a Windows system over TCP/IP to debug Windows programs.
4387 * The GDB remote stub, gdbserver, has been updated to support Windows and
4388 Cygwin debugging. Both single-threaded and multi-threaded programs are
4391 * The "set trust-readonly-sections" command works again. This command was
4392 broken in GDB 6.3, 6.4, and 6.5.
4394 * The "load" command now supports writing to flash memory, if the remote
4395 stub provides the required support.
4397 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4398 longer requires symbolic debug information (e.g. DWARF-2).
4403 unset substitute-path
4404 show substitute-path
4405 Manage a list of substitution rules that GDB uses to rewrite the name
4406 of the directories where the sources are located. This can be useful
4407 for instance when the sources were moved to a different location
4408 between compilation and debugging.
4412 Print each CLI command as it is executed. Each command is prefixed with
4413 a number of `+' symbols representing the nesting depth.
4414 The source command now has a `-v' option to enable the same feature.
4418 The ARM Demon monitor support (RDP protocol, "target rdp").
4420 Kernel Object Display, an embedded debugging feature which only worked with
4421 an obsolete version of Cisco IOS.
4423 The 'set download-write-size' and 'show download-write-size' commands.
4425 * New remote packets
4428 Tell a stub about GDB client features, and request remote target features.
4429 The first feature implemented is PacketSize, which allows the target to
4430 specify the size of packets it can handle - to minimize the number of
4431 packets required and improve performance when connected to a remote
4435 Fetch an OS auxilliary vector from the remote stub. This packet is a
4436 more efficient replacement for qPart:auxv:read.
4438 qXfer:memory-map:read:
4439 Fetch a memory map from the remote stub, including information about
4440 RAM, ROM, and flash memory devices.
4445 Erase and program a flash memory device.
4447 * Removed remote packets
4450 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4451 used it, and only gdbserver implemented it.
4453 *** Changes in GDB 6.5
4457 Renesas M32C/M16C m32c-elf
4459 Morpho Technologies ms1 ms1-elf
4463 init-if-undefined Initialize a convenience variable, but
4464 only if it doesn't already have a value.
4466 The following commands are presently only implemented for native GNU/Linux:
4468 checkpoint Save a snapshot of the program state.
4470 restart <n> Return the program state to a
4471 previously saved state.
4473 info checkpoints List currently saved checkpoints.
4475 delete-checkpoint <n> Delete a previously saved checkpoint.
4477 set|show detach-on-fork Tell gdb whether to detach from a newly
4478 forked process, or to keep debugging it.
4480 info forks List forks of the user program that
4481 are available to be debugged.
4483 fork <n> Switch to debugging one of several
4484 forks of the user program that are
4485 available to be debugged.
4487 delete-fork <n> Delete a fork from the list of forks
4488 that are available to be debugged (and
4489 kill the forked process).
4491 detach-fork <n> Delete a fork from the list of forks
4492 that are available to be debugged (and
4493 allow the process to continue).
4497 Morpho Technologies ms2 ms1-elf
4499 * Improved Windows host support
4501 GDB now builds as a cross debugger hosted on i686-mingw32, including
4502 native console support, and remote communications using either
4503 network sockets or serial ports.
4505 * Improved Modula-2 language support
4507 GDB can now print most types in the Modula-2 syntax. This includes:
4508 basic types, set types, record types, enumerated types, range types,
4509 pointer types and ARRAY types. Procedure var parameters are correctly
4510 printed and hexadecimal addresses and character constants are also
4511 written in the Modula-2 syntax. Best results can be obtained by using
4512 GNU Modula-2 together with the -gdwarf-2 command line option.
4516 The ARM rdi-share module.
4518 The Netware NLM debug server.
4520 *** Changes in GDB 6.4
4522 * New native configurations
4524 OpenBSD/arm arm*-*-openbsd*
4525 OpenBSD/mips64 mips64-*-openbsd*
4529 Morpho Technologies ms1 ms1-elf
4531 * New command line options
4533 --batch-silent As for --batch, but totally silent.
4534 --return-child-result The debugger will exist with the same value
4535 the child (debugged) program exited with.
4536 --eval-command COMMAND, -ex COMMAND
4537 Execute a single GDB CLI command. This may be
4538 specified multiple times and in conjunction
4539 with the --command (-x) option.
4541 * Deprecated commands removed
4543 The following commands, that were deprecated in 2000, have been
4547 set|show arm disassembly-flavor set|show arm disassembler
4548 othernames set arm disassembler
4549 set|show remotedebug set|show debug remote
4550 set|show archdebug set|show debug arch
4551 set|show eventdebug set|show debug event
4554 * New BSD user-level threads support
4556 It is now possible to debug programs using the user-level threads
4557 library on OpenBSD and FreeBSD. Currently supported (target)
4560 FreeBSD/amd64 x86_64-*-freebsd*
4561 FreeBSD/i386 i386-*-freebsd*
4562 OpenBSD/i386 i386-*-openbsd*
4564 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4565 are not yet supported.
4567 * New support for Matsushita MN10300 w/sim added
4568 (Work in progress). mn10300-elf.
4570 * REMOVED configurations and files
4572 VxWorks and the XDR protocol *-*-vxworks
4573 Motorola MCORE mcore-*-*
4574 National Semiconductor NS32000 ns32k-*-*
4576 * New "set print array-indexes" command
4578 After turning this setting "on", GDB prints the index of each element
4579 when displaying arrays. The default is "off" to preserve the previous
4582 * VAX floating point support
4584 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4586 * User-defined command support
4588 In addition to using $arg0..$arg9 for argument passing, it is now possible
4589 to use $argc to determine now many arguments have been passed. See the
4590 section on user-defined commands in the user manual for more information.
4592 *** Changes in GDB 6.3:
4594 * New command line option
4596 GDB now accepts -l followed by a number to set the timeout for remote
4599 * GDB works with GCC -feliminate-dwarf2-dups
4601 GDB now supports a more compact representation of DWARF-2 debug
4602 information using DW_FORM_ref_addr references. These are produced
4603 by GCC with the option -feliminate-dwarf2-dups and also by some
4604 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4605 to use -feliminate-dwarf2-dups.
4607 * Internationalization
4609 When supported by the host system, GDB will be built with
4610 internationalization (libintl). The task of marking up the sources is
4611 continued, we're looking forward to our first translation.
4615 Initial support for debugging programs compiled with the GNAT
4616 implementation of the Ada programming language has been integrated
4617 into GDB. In this release, support is limited to expression evaluation.
4619 * New native configurations
4621 GNU/Linux/m32r m32r-*-linux-gnu
4625 GDB's remote protocol now includes support for the 'p' packet. This
4626 packet is used to fetch individual registers from a remote inferior.
4628 * END-OF-LIFE registers[] compatibility module
4630 GDB's internal register infrastructure has been completely rewritten.
4631 The new infrastructure making possible the implementation of key new
4632 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4635 GDB 6.3 will be the last release to include the the registers[]
4636 compatibility module that allowed out-of-date configurations to
4637 continue to work. This change directly impacts the following
4647 powerpc bdm protocol
4649 Unless there is activity to revive these configurations, they will be
4650 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4652 * OBSOLETE configurations and files
4654 Configurations that have been declared obsolete in this release have
4655 been commented out. Unless there is activity to revive these
4656 configurations, the next release of GDB will have their sources
4657 permanently REMOVED.
4666 *** Changes in GDB 6.2.1:
4668 * MIPS `break main; run' gave an heuristic-fence-post warning
4670 When attempting to run even a simple program, a warning about
4671 heuristic-fence-post being hit would be reported. This problem has
4674 * MIPS IRIX 'long double' crashed GDB
4676 When examining a long double variable, GDB would get a segmentation
4677 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4678 IRIX long double values).
4682 A bug in the VAX stack code was causing problems with the "next"
4683 command. This problem has been fixed.
4685 *** Changes in GDB 6.2:
4687 * Fix for ``many threads''
4689 On GNU/Linux systems that use the NPTL threads library, a program
4690 rapidly creating and deleting threads would confuse GDB leading to the
4693 ptrace: No such process.
4694 thread_db_get_info: cannot get thread info: generic error
4696 This problem has been fixed.
4698 * "-async" and "-noasync" options removed.
4700 Support for the broken "-noasync" option has been removed (it caused
4703 * New ``start'' command.
4705 This command runs the program until the begining of the main procedure.
4707 * New BSD Kernel Data Access Library (libkvm) interface
4709 Using ``target kvm'' it is now possible to debug kernel core dumps and
4710 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4711 platforms. Currently supported (native-only) configurations are:
4713 FreeBSD/amd64 x86_64-*-freebsd*
4714 FreeBSD/i386 i?86-*-freebsd*
4715 NetBSD/i386 i?86-*-netbsd*
4716 NetBSD/m68k m68*-*-netbsd*
4717 NetBSD/sparc sparc-*-netbsd*
4718 OpenBSD/amd64 x86_64-*-openbsd*
4719 OpenBSD/i386 i?86-*-openbsd*
4720 OpenBSD/m68k m68*-openbsd*
4721 OpenBSD/sparc sparc-*-openbsd*
4723 * Signal trampoline code overhauled
4725 Many generic problems with GDB's signal handling code have been fixed.
4726 These include: backtraces through non-contiguous stacks; recognition
4727 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4728 call; backtrace through a signal trampoline; step into and out of
4729 signal handlers; and single-stepping in the signal trampoline.
4731 Please note that kernel bugs are a limiting factor here. These
4732 features have been shown to work on an s390 GNU/Linux system that
4733 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4735 * Cygwin support for DWARF 2 added.
4737 * New native configurations
4739 GNU/Linux/hppa hppa*-*-linux*
4740 OpenBSD/hppa hppa*-*-openbsd*
4741 OpenBSD/m68k m68*-*-openbsd*
4742 OpenBSD/m88k m88*-*-openbsd*
4743 OpenBSD/powerpc powerpc-*-openbsd*
4744 NetBSD/vax vax-*-netbsd*
4745 OpenBSD/vax vax-*-openbsd*
4747 * END-OF-LIFE frame compatibility module
4749 GDB's internal frame infrastructure has been completely rewritten.
4750 The new infrastructure making it possible to support key new features
4751 including DWARF 2 Call Frame Information. To aid in the task of
4752 migrating old configurations to this new infrastructure, a
4753 compatibility module, that allowed old configurations to continue to
4754 work, was also included.
4756 GDB 6.2 will be the last release to include this frame compatibility
4757 module. This change directly impacts the following configurations:
4767 Unless there is activity to revive these configurations, they will be
4768 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4770 * REMOVED configurations and files
4772 Sun 3, running SunOS 3 m68*-*-sunos3*
4773 Sun 3, running SunOS 4 m68*-*-sunos4*
4774 Sun 2, running SunOS 3 m68000-*-sunos3*
4775 Sun 2, running SunOS 4 m68000-*-sunos4*
4776 Motorola 680x0 running LynxOS m68*-*-lynxos*
4777 AT&T 3b1/Unix pc m68*-att-*
4778 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4779 decstation mips-dec-* mips-little-*
4780 riscos mips-*-riscos* mips-*-sysv*
4781 sonymips mips-sony-*
4782 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4784 *** Changes in GDB 6.1.1:
4786 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4788 The TUI (Text-mode User Interface) is now built as part of a default
4789 GDB configuration. It is enabled by either selecting the TUI with the
4790 command line option "-i=tui" or by running the separate "gdbtui"
4791 program. For more information on the TUI, see the manual "Debugging
4794 * Pending breakpoint support (also included in GDB 6.1)
4796 Support has been added to allow you to specify breakpoints in shared
4797 libraries that have not yet been loaded. If a breakpoint location
4798 cannot be found, and the "breakpoint pending" option is set to auto,
4799 GDB queries you if you wish to make the breakpoint pending on a future
4800 shared-library load. If and when GDB resolves the breakpoint symbol,
4801 the pending breakpoint is removed as one or more regular breakpoints
4804 Pending breakpoints are very useful for GCJ Java debugging.
4806 * Fixed ISO-C build problems
4808 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4809 non ISO-C code that stopped them being built using a more strict ISO-C
4810 compiler (e.g., IBM's C compiler).
4812 * Fixed build problem on IRIX 5
4814 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4815 wasn't able to compile compile on an IRIX 5 system.
4817 * Added execute permission to gdb/gdbserver/configure
4819 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4820 permission. This bug would cause configure to fail on a number of
4821 systems (Solaris, IRIX). Ref: server/519.
4823 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4825 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4826 has been updated to use constant array sizes.
4828 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4830 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4831 its generated DWARF Call Frame Info. This encoding was causing GDB to
4832 panic, that panic has been fixed. Ref: gdb/1628.
4834 * Fixed a problem when examining parameters in shared library code.
4836 When examining parameters in optimized shared library code generated
4837 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4838 not available''. GDB now correctly displays the variable's value.
4840 *** Changes in GDB 6.1:
4842 * Removed --with-mmalloc
4844 Support for the mmalloc memory manager has been removed, as it
4845 conflicted with the internal gdb byte cache.
4847 * Changes in AMD64 configurations
4849 The AMD64 target now includes the %cs and %ss registers. As a result
4850 the AMD64 remote protocol has changed; this affects the floating-point
4851 and SSE registers. If you rely on those registers for your debugging,
4852 you should upgrade gdbserver on the remote side.
4854 * Revised SPARC target
4856 The SPARC target has been completely revised, incorporating the
4857 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4858 support for LynxOS and SunOS 4 has been dropped. Calling functions
4859 from within GDB on operating systems with a non-executable stack
4860 (Solaris, OpenBSD) now works.
4864 GDB has a new C++ demangler which does a better job on the mangled
4865 names generated by current versions of g++. It also runs faster, so
4866 with this and other changes gdb should now start faster on large C++
4869 * DWARF 2 Location Expressions
4871 GDB support for location expressions has been extended to support function
4872 arguments and frame bases. Older versions of GDB could crash when they
4875 * C++ nested types and namespaces
4877 GDB's support for nested types and namespaces in C++ has been
4878 improved, especially if you use the DWARF 2 debugging format. (This
4879 is the default for recent versions of GCC on most platforms.)
4880 Specifically, if you have a class "Inner" defined within a class or
4881 namespace "Outer", then GDB realizes that the class's name is
4882 "Outer::Inner", not simply "Inner". This should greatly reduce the
4883 frequency of complaints about not finding RTTI symbols. In addition,
4884 if you are stopped at inside of a function defined within a namespace,
4885 GDB modifies its name lookup accordingly.
4887 * New native configurations
4889 NetBSD/amd64 x86_64-*-netbsd*
4890 OpenBSD/amd64 x86_64-*-openbsd*
4891 OpenBSD/alpha alpha*-*-openbsd*
4892 OpenBSD/sparc sparc-*-openbsd*
4893 OpenBSD/sparc64 sparc64-*-openbsd*
4895 * New debugging protocols
4897 M32R with SDI protocol m32r-*-elf*
4899 * "set prompt-escape-char" command deleted.
4901 The command "set prompt-escape-char" has been deleted. This command,
4902 and its very obscure effet on GDB's prompt, was never documented,
4903 tested, nor mentioned in the NEWS file.
4905 * OBSOLETE configurations and files
4907 Configurations that have been declared obsolete in this release have
4908 been commented out. Unless there is activity to revive these
4909 configurations, the next release of GDB will have their sources
4910 permanently REMOVED.
4912 Sun 3, running SunOS 3 m68*-*-sunos3*
4913 Sun 3, running SunOS 4 m68*-*-sunos4*
4914 Sun 2, running SunOS 3 m68000-*-sunos3*
4915 Sun 2, running SunOS 4 m68000-*-sunos4*
4916 Motorola 680x0 running LynxOS m68*-*-lynxos*
4917 AT&T 3b1/Unix pc m68*-att-*
4918 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4919 decstation mips-dec-* mips-little-*
4920 riscos mips-*-riscos* mips-*-sysv*
4921 sonymips mips-sony-*
4922 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4924 * REMOVED configurations and files
4926 SGI Irix-4.x mips-sgi-irix4 or iris4
4927 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4928 Z8000 simulator z8k-zilog-none or z8ksim
4929 Matsushita MN10200 w/simulator mn10200-*-*
4930 H8/500 simulator h8500-hitachi-hms or h8500hms
4931 HP/PA running BSD hppa*-*-bsd*
4932 HP/PA running OSF/1 hppa*-*-osf*
4933 HP/PA Pro target hppa*-*-pro*
4934 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4935 386BSD i[3456]86-*-bsd*
4936 Sequent family i[3456]86-sequent-sysv4*
4937 i[3456]86-sequent-sysv*
4938 i[3456]86-sequent-bsd*
4939 SPARC running LynxOS sparc-*-lynxos*
4940 SPARC running SunOS 4 sparc-*-sunos4*
4941 Tsqware Sparclet sparclet-*-*
4942 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4944 *** Changes in GDB 6.0:
4948 Support for debugging the Objective-C programming language has been
4949 integrated into GDB.
4951 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4953 DWARF 2's Call Frame Information makes available compiler generated
4954 information that more exactly describes the program's run-time stack.
4955 By using this information, GDB is able to provide more robust stack
4958 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4959 have been updated to use a new backtrace mechanism which includes
4960 DWARF 2 CFI support.
4964 GDB's remote protocol has been extended to include support for hosted
4965 file I/O (where the remote target uses GDB's file system). See GDB's
4966 remote protocol documentation for details.
4968 * All targets using the new architecture framework.
4970 All of GDB's targets have been updated to use the new internal
4971 architecture framework. The way is now open for future GDB releases
4972 to include cross-architecture native debugging support (i386 on amd64,
4975 * GNU/Linux's Thread Local Storage (TLS)
4977 GDB now includes support for for the GNU/Linux implementation of
4978 per-thread variables.
4980 * GNU/Linux's Native POSIX Thread Library (NPTL)
4982 GDB's thread code has been updated to work with either the new
4983 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4985 * Separate debug info.
4987 GDB, in conjunction with BINUTILS, now supports a mechanism for
4988 automatically loading debug information from a separate file. Instead
4989 of shipping full debug and non-debug versions of system libraries,
4990 system integrators can now instead ship just the stripped libraries
4991 and optional debug files.
4993 * DWARF 2 Location Expressions
4995 DWARF 2 Location Expressions allow the compiler to more completely
4996 describe the location of variables (even in optimized code) to the
4999 GDB now includes preliminary support for location expressions (support
5000 for DW_OP_piece is still missing).
5004 A number of long standing bugs that caused GDB to die while starting a
5005 Java application have been fixed. GDB's Java support is now
5006 considered "useable".
5008 * GNU/Linux support for fork, vfork, and exec.
5010 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5011 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5014 * GDB supports logging output to a file
5016 There are two new commands, "set logging" and "show logging", which can be
5017 used to capture GDB's output to a file.
5019 * The meaning of "detach" has changed for gdbserver
5021 The "detach" command will now resume the application, as documented. To
5022 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5025 * d10v, m68hc11 `regs' command deprecated
5027 The `info registers' command has been updated so that it displays the
5028 registers using a format identical to the old `regs' command.
5032 A new command, "maint set profile on/off", has been added. This command can
5033 be used to enable or disable profiling while running GDB, to profile a
5034 session or a set of commands. In addition there is a new configure switch,
5035 "--enable-profiling", which will cause GDB to be compiled with profiling
5036 data, for more informative profiling results.
5038 * Default MI syntax changed to "mi2".
5040 The default MI (machine interface) syntax, enabled by the command line
5041 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5042 "mi1", can be enabled by specifying the option "-i=mi1".
5044 Support for the original "mi0" syntax (included in GDB 5.0) has been
5047 Fix for gdb/192: removed extraneous space when displaying frame level.
5048 Fix for gdb/672: update changelist is now output in mi list format.
5049 Fix for gdb/702: a -var-assign that updates the value now shows up
5050 in a subsequent -var-update.
5052 * New native configurations.
5054 FreeBSD/amd64 x86_64-*-freebsd*
5056 * Multi-arched targets.
5058 HP/PA HPUX11 hppa*-*-hpux*
5059 Renesas M32R/D w/simulator m32r-*-elf*
5061 * OBSOLETE configurations and files
5063 Configurations that have been declared obsolete in this release have
5064 been commented out. Unless there is activity to revive these
5065 configurations, the next release of GDB will have their sources
5066 permanently REMOVED.
5068 Z8000 simulator z8k-zilog-none or z8ksim
5069 Matsushita MN10200 w/simulator mn10200-*-*
5070 H8/500 simulator h8500-hitachi-hms or h8500hms
5071 HP/PA running BSD hppa*-*-bsd*
5072 HP/PA running OSF/1 hppa*-*-osf*
5073 HP/PA Pro target hppa*-*-pro*
5074 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5075 Sequent family i[3456]86-sequent-sysv4*
5076 i[3456]86-sequent-sysv*
5077 i[3456]86-sequent-bsd*
5078 Tsqware Sparclet sparclet-*-*
5079 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5081 * REMOVED configurations and files
5084 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5085 IBM AIX PS/2 i[3456]86-*-aix
5086 i386 running Mach 3.0 i[3456]86-*-mach3*
5087 i386 running Mach i[3456]86-*-mach*
5088 i386 running OSF/1 i[3456]86-*osf1mk*
5089 HP/Apollo 68k Family m68*-apollo*-sysv*,
5091 m68*-hp-bsd*, m68*-hp-hpux*
5092 Argonaut Risc Chip (ARC) arc-*-*
5093 Mitsubishi D30V d30v-*-*
5094 Fujitsu FR30 fr30-*-elf*
5095 OS/9000 i[34]86-*-os9k
5096 I960 with MON960 i960-*-coff
5098 * MIPS $fp behavior changed
5100 The convenience variable $fp, for the MIPS, now consistently returns
5101 the address of the current frame's base. Previously, depending on the
5102 context, $fp could refer to either $sp or the current frame's base
5103 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5104 The GNU Source-Level Debugger''.
5106 *** Changes in GDB 5.3:
5108 * GNU/Linux shared library multi-threaded performance improved.
5110 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5111 `/proc', in preference to `ptrace' for memory reads. This may result
5112 in an improvement in the start-up time of multi-threaded, shared
5113 library applications when run under GDB. One GDB user writes: ``loads
5114 shared libs like mad''.
5116 * ``gdbserver'' now supports multi-threaded applications on some targets
5118 Support for debugging multi-threaded applications which use
5119 the GNU/Linux LinuxThreads package has been added for
5120 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5121 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5123 * GDB now supports C/C++ preprocessor macros.
5125 GDB now expands preprocessor macro invocations in C/C++ expressions,
5126 and provides various commands for showing macro definitions and how
5129 The new command `macro expand EXPRESSION' expands any macro
5130 invocations in expression, and shows the result.
5132 The new command `show macro MACRO-NAME' shows the definition of the
5133 macro named MACRO-NAME, and where it was defined.
5135 Most compilers don't include information about macros in the debugging
5136 information by default. In GCC 3.1, for example, you need to compile
5137 your program with the options `-gdwarf-2 -g3'. If the macro
5138 information is present in the executable, GDB will read it.
5140 * Multi-arched targets.
5142 DEC Alpha (partial) alpha*-*-*
5143 DEC VAX (partial) vax-*-*
5145 National Semiconductor NS32000 (partial) ns32k-*-*
5146 Motorola 68000 (partial) m68k-*-*
5147 Motorola MCORE mcore-*-*
5151 Fujitsu FRV architecture added by Red Hat frv*-*-*
5154 * New native configurations
5156 Alpha NetBSD alpha*-*-netbsd*
5157 SH NetBSD sh*-*-netbsdelf*
5158 MIPS NetBSD mips*-*-netbsd*
5159 UltraSPARC NetBSD sparc64-*-netbsd*
5161 * OBSOLETE configurations and files
5163 Configurations that have been declared obsolete in this release have
5164 been commented out. Unless there is activity to revive these
5165 configurations, the next release of GDB will have their sources
5166 permanently REMOVED.
5168 Mitsubishi D30V d30v-*-*
5169 OS/9000 i[34]86-*-os9k
5170 IBM AIX PS/2 i[3456]86-*-aix
5171 Fujitsu FR30 fr30-*-elf*
5172 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5173 Argonaut Risc Chip (ARC) arc-*-*
5174 i386 running Mach 3.0 i[3456]86-*-mach3*
5175 i386 running Mach i[3456]86-*-mach*
5176 i386 running OSF/1 i[3456]86-*osf1mk*
5177 HP/Apollo 68k Family m68*-apollo*-sysv*,
5179 m68*-hp-bsd*, m68*-hp-hpux*
5180 I960 with MON960 i960-*-coff
5182 * OBSOLETE languages
5184 CHILL, a Pascal like language used by telecommunications companies.
5186 * REMOVED configurations and files
5188 AMD 29k family via UDI a29k-amd-udi, udi29k
5189 A29K VxWorks a29k-*-vxworks
5190 AMD 29000 embedded, using EBMON a29k-none-none
5191 AMD 29000 embedded with COFF a29k-none-coff
5192 AMD 29000 embedded with a.out a29k-none-aout
5194 testsuite/gdb.hp/gdb.threads-hp/ directory
5196 * New command "set max-user-call-depth <nnn>"
5198 This command allows the user to limit the call depth of user-defined
5199 commands. The default is 1024.
5201 * Changes in FreeBSD/i386 native debugging.
5203 Support for the "generate-core-file" has been added.
5205 * New commands "dump", "append", and "restore".
5207 These commands allow data to be copied from target memory
5208 to a bfd-format or binary file (dump and append), and back
5209 from a file into memory (restore).
5211 * Improved "next/step" support on multi-processor Alpha Tru64.
5213 The previous single-step mechanism could cause unpredictable problems,
5214 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5215 of a software single-step mechanism prevents this.
5217 *** Changes in GDB 5.2.1:
5225 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5226 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5227 Fix, by Joel Brobecker imported from mainline.
5229 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5230 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5231 Fix, by Fred Fish, imported from mainline.
5233 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5234 Surprisingly enough, it works now.
5235 By Michal Ludvig, imported from mainline.
5237 i386 hardware watchpoint support:
5238 avoid misses on second run for some targets.
5239 By Pierre Muller, imported from mainline.
5241 *** Changes in GDB 5.2:
5243 * New command "set trust-readonly-sections on[off]".
5245 This command is a hint that tells gdb that read-only sections
5246 really are read-only (ie. that their contents will not change).
5247 In this mode, gdb will go to the object file rather than the
5248 target to read memory from read-only sections (such as ".text").
5249 This can be a significant performance improvement on some
5250 (notably embedded) targets.
5252 * New command "generate-core-file" (or "gcore").
5254 This new gdb command allows the user to drop a core file of the child
5255 process state at any time. So far it's been implemented only for
5256 GNU/Linux and Solaris, but should be relatively easily ported to other
5257 hosts. Argument is core file name (defaults to core.<pid>).
5259 * New command line option
5261 GDB now accepts --pid or -p followed by a process id.
5263 * Change in command line behavior -- corefiles vs. process ids.
5265 There is a subtle behavior in the way in which GDB handles
5266 command line arguments. The first non-flag argument is always
5267 a program to debug, but the second non-flag argument may either
5268 be a corefile or a process id. Previously, GDB would attempt to
5269 open the second argument as a corefile, and if that failed, would
5270 issue a superfluous error message and then attempt to attach it as
5271 a process. Now, if the second argument begins with a non-digit,
5272 it will be treated as a corefile. If it begins with a digit,
5273 GDB will attempt to attach it as a process, and if no such process
5274 is found, will then attempt to open it as a corefile.
5276 * Changes in ARM configurations.
5278 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5279 configuration is fully multi-arch.
5281 * New native configurations
5283 ARM NetBSD arm*-*-netbsd*
5284 x86 OpenBSD i[3456]86-*-openbsd*
5285 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5286 Sparc64 running FreeBSD sparc64-*-freebsd*
5290 Sanyo XStormy16 xstormy16-elf
5292 * OBSOLETE configurations and files
5294 Configurations that have been declared obsolete in this release have
5295 been commented out. Unless there is activity to revive these
5296 configurations, the next release of GDB will have their sources
5297 permanently REMOVED.
5299 AMD 29k family via UDI a29k-amd-udi, udi29k
5300 A29K VxWorks a29k-*-vxworks
5301 AMD 29000 embedded, using EBMON a29k-none-none
5302 AMD 29000 embedded with COFF a29k-none-coff
5303 AMD 29000 embedded with a.out a29k-none-aout
5305 testsuite/gdb.hp/gdb.threads-hp/ directory
5307 * REMOVED configurations and files
5309 TI TMS320C80 tic80-*-*
5311 PowerPC Solaris powerpcle-*-solaris*
5312 PowerPC Windows NT powerpcle-*-cygwin32
5313 PowerPC Netware powerpc-*-netware*
5314 Harris/CXUX m88k m88*-harris-cxux*
5315 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5316 ns32k-utek-sysv* ns32k-utek-*
5317 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5318 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5319 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5320 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5321 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5323 * Changes to command line processing
5325 The new `--args' feature can be used to specify command-line arguments
5326 for the inferior from gdb's command line.
5328 * Changes to key bindings
5330 There is a new `operate-and-get-next' function bound to `C-o'.
5332 *** Changes in GDB 5.1.1
5334 Fix compile problem on DJGPP.
5336 Fix a problem with floating-point registers on the i386 being
5339 Fix to stop GDB crashing on .debug_str debug info.
5341 Numerous documentation fixes.
5343 Numerous testsuite fixes.
5345 *** Changes in GDB 5.1:
5347 * New native configurations
5349 Alpha FreeBSD alpha*-*-freebsd*
5350 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5351 MIPS GNU/Linux mips*-*-linux*
5352 MIPS SGI Irix 6.x mips*-sgi-irix6*
5353 ia64 AIX ia64-*-aix*
5354 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5358 Motorola 68HC11 and 68HC12 m68hc11-elf
5360 UltraSparc running GNU/Linux sparc64-*-linux*
5362 * OBSOLETE configurations and files
5364 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5365 Harris/CXUX m88k m88*-harris-cxux*
5366 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5367 ns32k-utek-sysv* ns32k-utek-*
5368 TI TMS320C80 tic80-*-*
5370 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5371 PowerPC Solaris powerpcle-*-solaris*
5372 PowerPC Windows NT powerpcle-*-cygwin32
5373 PowerPC Netware powerpc-*-netware*
5374 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5375 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5376 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5377 Apple Macintosh (MPW) host N/A
5379 stuff.c (Program to stuff files into a specially prepared space in kdb)
5380 kdb-start.c (Main loop for the standalone kernel debugger)
5382 Configurations that have been declared obsolete in this release have
5383 been commented out. Unless there is activity to revive these
5384 configurations, the next release of GDB will have their sources
5385 permanently REMOVED.
5387 * REMOVED configurations and files
5389 Altos 3068 m68*-altos-*
5390 Convex c1-*-*, c2-*-*
5392 ARM RISCix arm-*-* (as host)
5396 * GDB has been converted to ISO C.
5398 GDB's source code has been converted to ISO C. In particular, the
5399 sources are fully protoized, and rely on standard headers being
5404 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5406 * The MI enabled by default.
5408 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5409 revised and enabled by default. Packages which use GDB as a debugging
5410 engine behind a UI or another front end are encouraged to switch to
5411 using the GDB/MI interface, instead of the old annotations interface
5412 which is now deprecated.
5414 * Support for debugging Pascal programs.
5416 GDB now includes support for debugging Pascal programs. The following
5417 main features are supported:
5419 - Pascal-specific data types such as sets;
5421 - automatic recognition of Pascal sources based on file-name
5424 - Pascal-style display of data types, variables, and functions;
5426 - a Pascal expression parser.
5428 However, some important features are not yet supported.
5430 - Pascal string operations are not supported at all;
5432 - there are some problems with boolean types;
5434 - Pascal type hexadecimal constants are not supported
5435 because they conflict with the internal variables format;
5437 - support for Pascal objects and classes is not full yet;
5439 - unlike Pascal, GDB is case-sensitive for symbol names.
5441 * Changes in completion.
5443 Commands such as `shell', `run' and `set args', which pass arguments
5444 to inferior programs, now complete on file names, similar to what
5445 users expect at the shell prompt.
5447 Commands which accept locations, such as `disassemble', `print',
5448 `breakpoint', `until', etc. now complete on filenames as well as
5449 program symbols. Thus, if you type "break foob TAB", and the source
5450 files linked into the programs include `foobar.c', that file name will
5451 be one of the candidates for completion. However, file names are not
5452 considered for completion after you typed a colon that delimits a file
5453 name from a name of a function in that file, as in "break foo.c:bar".
5455 `set demangle-style' completes on available demangling styles.
5457 * New platform-independent commands:
5459 It is now possible to define a post-hook for a command as well as a
5460 hook that runs before the command. For more details, see the
5461 documentation of `hookpost' in the GDB manual.
5463 * Changes in GNU/Linux native debugging.
5465 Support for debugging multi-threaded programs has been completely
5466 revised for all platforms except m68k and sparc. You can now debug as
5467 many threads as your system allows you to have.
5469 Attach/detach is supported for multi-threaded programs.
5471 Support for SSE registers was added for x86. This doesn't work for
5472 multi-threaded programs though.
5474 * Changes in MIPS configurations.
5476 Multi-arch support is enabled for all MIPS configurations.
5478 GDB can now be built as native debugger on SGI Irix 6.x systems for
5479 debugging n32 executables. (Debugging 64-bit executables is not yet
5482 * Unified support for hardware watchpoints in all x86 configurations.
5484 Most (if not all) native x86 configurations support hardware-assisted
5485 breakpoints and watchpoints in a unified manner. This support
5486 implements debug register sharing between watchpoints, which allows to
5487 put a virtually infinite number of watchpoints on the same address,
5488 and also supports watching regions up to 16 bytes with several debug
5491 The new maintenance command `maintenance show-debug-regs' toggles
5492 debugging print-outs in functions that insert, remove, and test
5493 watchpoints and hardware breakpoints.
5495 * Changes in the DJGPP native configuration.
5497 New command ``info dos sysinfo'' displays assorted information about
5498 the CPU, OS, memory, and DPMI server.
5500 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5501 display information about segment descriptors stored in GDT, LDT, and
5504 New commands ``info dos pde'' and ``info dos pte'' display entries
5505 from Page Directory and Page Tables (for now works with CWSDPMI only).
5506 New command ``info dos address-pte'' displays the Page Table entry for
5507 a given linear address.
5509 GDB can now pass command lines longer than 126 characters to the
5510 program being debugged (requires an update to the libdbg.a library
5511 which is part of the DJGPP development kit).
5513 DWARF2 debug info is now supported.
5515 It is now possible to `step' and `next' through calls to `longjmp'.
5517 * Changes in documentation.
5519 All GDB documentation was converted to GFDL, the GNU Free
5520 Documentation License.
5522 Tracepoints-related commands are now fully documented in the GDB
5525 TUI, the Text-mode User Interface, is now documented in the manual.
5527 Tracepoints-related commands are now fully documented in the GDB
5530 The "GDB Internals" manual now has an index. It also includes
5531 documentation of `ui_out' functions, GDB coding standards, x86
5532 hardware watchpoints, and memory region attributes.
5534 * GDB's version number moved to ``version.in''
5536 The Makefile variable VERSION has been replaced by the file
5537 ``version.in''. People creating GDB distributions should update the
5538 contents of this file.
5542 GUD support is now a standard part of the EMACS distribution.
5544 *** Changes in GDB 5.0:
5546 * Improved support for debugging FP programs on x86 targets
5548 Unified and much-improved support for debugging floating-point
5549 programs on all x86 targets. In particular, ``info float'' now
5550 displays the FP registers in the same format on all x86 targets, with
5551 greater level of detail.
5553 * Improvements and bugfixes in hardware-assisted watchpoints
5555 It is now possible to watch array elements, struct members, and
5556 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5557 on x86 targets no longer erroneously trigger when the address is
5560 * Improvements in the native DJGPP version of GDB
5562 The distribution now includes all the scripts and auxiliary files
5563 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5564 machines ``out of the box''.
5566 The DJGPP version can now debug programs that use signals. It is
5567 possible to catch signals that happened in the debuggee, deliver
5568 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5569 would kill the program being debugged.) Programs that hook hardware
5570 interrupts (keyboard, timer, etc.) can also be debugged.
5572 It is now possible to debug DJGPP programs that redirect their
5573 standard handles or switch them to raw (as opposed to cooked) mode, or
5574 even close them. The command ``run < foo > bar'' works as expected,
5575 and ``info terminal'' reports useful information about the debuggee's
5576 terminal, including raw/cooked mode, redirection, etc.
5578 The DJGPP version now uses termios functions for console I/O, which
5579 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5582 DOS-style file names with drive letters are now fully supported by
5585 It is now possible to debug DJGPP programs that switch their working
5586 directory. It is also possible to rerun the debuggee any number of
5587 times without restarting GDB; thus, you can use the same setup,
5588 breakpoints, etc. for many debugging sessions.
5590 * New native configurations
5592 ARM GNU/Linux arm*-*-linux*
5593 PowerPC GNU/Linux powerpc-*-linux*
5597 Motorola MCore mcore-*-*
5598 x86 VxWorks i[3456]86-*-vxworks*
5599 PowerPC VxWorks powerpc-*-vxworks*
5600 TI TMS320C80 tic80-*-*
5602 * OBSOLETE configurations
5604 Altos 3068 m68*-altos-*
5605 Convex c1-*-*, c2-*-*
5607 ARM RISCix arm-*-* (as host)
5610 Configurations that have been declared obsolete will be commented out,
5611 but the code will be left in place. If there is no activity to revive
5612 these configurations before the next release of GDB, the sources will
5613 be permanently REMOVED.
5615 * Gould support removed
5617 Support for the Gould PowerNode and NP1 has been removed.
5619 * New features for SVR4
5621 On SVR4 native platforms (such as Solaris), if you attach to a process
5622 without first loading a symbol file, GDB will now attempt to locate and
5623 load symbols from the running process's executable file.
5625 * Many C++ enhancements
5627 C++ support has been greatly improved. Overload resolution now works properly
5628 in almost all cases. RTTI support is on the way.
5630 * Remote targets can connect to a sub-program
5632 A popen(3) style serial-device has been added. This device starts a
5633 sub-process (such as a stand-alone simulator) and then communicates
5634 with that. The sub-program to run is specified using the syntax
5635 ``|<program> <args>'' vis:
5637 (gdb) set remotedebug 1
5638 (gdb) target extended-remote |mn10300-elf-sim program-args
5640 * MIPS 64 remote protocol
5642 A long standing bug in the mips64 remote protocol where by GDB
5643 expected certain 32 bit registers (ex SR) to be transfered as 32
5644 instead of 64 bits has been fixed.
5646 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5647 added to provide backward compatibility with older versions of GDB.
5649 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5651 The command ``set remotebinarydownload'' command has been replaced by
5652 ``set remote X-packet''. Other commands in ``set remote'' family
5653 include ``set remote P-packet''.
5655 * Breakpoint commands accept ranges.
5657 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5658 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5659 ``tracepoint passcount'' also accepts a range of tracepoints.
5661 * ``apropos'' command added.
5663 The ``apropos'' command searches through command names and
5664 documentation strings, printing out matches, making it much easier to
5665 try to find a command that does what you are looking for.
5669 A new machine oriented interface (MI) has been added to GDB. This
5670 interface is designed for debug environments running GDB as a separate
5671 process. This is part of the long term libGDB project. See the
5672 "GDB/MI" chapter of the GDB manual for further information. It can be
5673 enabled by configuring with:
5675 .../configure --enable-gdbmi
5677 *** Changes in GDB-4.18:
5679 * New native configurations
5681 HP-UX 10.20 hppa*-*-hpux10.20
5682 HP-UX 11.x hppa*-*-hpux11.0*
5683 M68K GNU/Linux m68*-*-linux*
5687 Fujitsu FR30 fr30-*-elf*
5688 Intel StrongARM strongarm-*-*
5689 Mitsubishi D30V d30v-*-*
5691 * OBSOLETE configurations
5693 Gould PowerNode, NP1 np1-*-*, pn-*-*
5695 Configurations that have been declared obsolete will be commented out,
5696 but the code will be left in place. If there is no activity to revive
5697 these configurations before the next release of GDB, the sources will
5698 be permanently REMOVED.
5702 As a compatibility experiment, GDB's source files buildsym.h and
5703 buildsym.c have been converted to pure standard C, no longer
5704 containing any K&R compatibility code. We believe that all systems in
5705 use today either come with a standard C compiler, or have a GCC port
5706 available. If this is not true, please report the affected
5707 configuration to bug-gdb@gnu.org immediately. See the README file for
5708 information about getting a standard C compiler if you don't have one
5713 GDB now uses readline 2.2.
5715 * set extension-language
5717 You can now control the mapping between filename extensions and source
5718 languages by using the `set extension-language' command. For instance,
5719 you can ask GDB to treat .c files as C++ by saying
5720 set extension-language .c c++
5721 The command `info extensions' lists all of the recognized extensions
5722 and their associated languages.
5724 * Setting processor type for PowerPC and RS/6000
5726 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5727 you can use the `set processor' command to specify what variant of the
5728 PowerPC family you are debugging. The command
5732 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5733 following PowerPC and RS6000 variants:
5735 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5736 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5738 403GC IBM PowerPC 403GC
5739 505 Motorola PowerPC 505
5740 860 Motorola PowerPC 860 or 850
5741 601 Motorola PowerPC 601
5742 602 Motorola PowerPC 602
5743 603 Motorola/IBM PowerPC 603 or 603e
5744 604 Motorola PowerPC 604 or 604e
5745 750 Motorola/IBM PowerPC 750 or 750
5747 At the moment, this command just tells GDB what to name the
5748 special-purpose processor registers. Since almost all the affected
5749 registers are inaccessible to user-level programs, this command is
5750 only useful for remote debugging in its present form.
5754 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5755 more extensive support for HP-UX. Added features include shared
5756 library support, kernel threads and hardware watchpoints for 11.00,
5757 support for HP's ANSI C and C++ compilers, and a compatibility mode
5758 for xdb and dbx commands.
5762 HP's donation includes the new concept of catchpoints, which is a
5763 generalization of the old catch command. On HP-UX, it is now possible
5764 to catch exec, fork, and vfork, as well as library loading.
5766 This means that the existing catch command has changed; its first
5767 argument now specifies the type of catch to be set up. See the
5768 output of "help catch" for a list of catchpoint types.
5770 * Debugging across forks
5772 On HP-UX, you can choose which process to debug when a fork() happens
5777 HP has donated a curses-based terminal user interface (TUI). To get
5778 it, build with --enable-tui. Although this can be enabled for any
5779 configuration, at present it only works for native HP debugging.
5781 * GDB remote protocol additions
5783 A new protocol packet 'X' that writes binary data is now available.
5784 Default behavior is to try 'X', then drop back to 'M' if the stub
5785 fails to respond. The settable variable `remotebinarydownload'
5786 allows explicit control over the use of 'X'.
5788 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5789 full 64-bit address. The command
5791 set remoteaddresssize 32
5793 can be used to revert to the old behaviour. For existing remote stubs
5794 the change should not be noticed, as the additional address information
5797 In order to assist in debugging stubs, you may use the maintenance
5798 command `packet' to send any text string to the stub. For instance,
5800 maint packet heythere
5802 sends the packet "$heythere#<checksum>". Note that it is very easy to
5803 disrupt a debugging session by sending the wrong packet at the wrong
5806 The compare-sections command allows you to compare section data on the
5807 target to what is in the executable file without uploading or
5808 downloading, by comparing CRC checksums.
5810 * Tracing can collect general expressions
5812 You may now collect general expressions at tracepoints. This requires
5813 further additions to the target-side stub; see tracepoint.c and
5814 doc/agentexpr.texi for further details.
5816 * mask-address variable for Mips
5818 For Mips targets, you may control the zeroing of the upper 32 bits of
5819 a 64-bit address by entering `set mask-address on'. This is mainly
5820 of interest to users of embedded R4xxx and R5xxx processors.
5822 * Higher serial baud rates
5824 GDB's serial code now allows you to specify baud rates 57600, 115200,
5825 230400, and 460800 baud. (Note that your host system may not be able
5826 to achieve all of these rates.)
5830 The i960 configuration now includes an initial implementation of a
5831 builtin simulator, contributed by Jim Wilson.
5834 *** Changes in GDB-4.17:
5836 * New native configurations
5838 Alpha GNU/Linux alpha*-*-linux*
5839 Unixware 2.x i[3456]86-unixware2*
5840 Irix 6.x mips*-sgi-irix6*
5841 PowerPC GNU/Linux powerpc-*-linux*
5842 PowerPC Solaris powerpcle-*-solaris*
5843 Sparc GNU/Linux sparc-*-linux*
5844 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5848 Argonaut Risc Chip (ARC) arc-*-*
5849 Hitachi H8/300S h8300*-*-*
5850 Matsushita MN10200 w/simulator mn10200-*-*
5851 Matsushita MN10300 w/simulator mn10300-*-*
5852 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5853 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5854 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5855 Mitsubishi D10V w/simulator d10v-*-*
5856 Mitsubishi M32R/D w/simulator m32r-*-elf*
5857 Tsqware Sparclet sparclet-*-*
5858 NEC V850 w/simulator v850-*-*
5860 * New debugging protocols
5862 ARM with RDI protocol arm*-*-*
5863 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5864 DDB and LSI variants of PMON protocol mips*-*-*
5865 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5866 PowerPC with SDS protocol powerpc{,le}-*-eabi
5867 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5871 All configurations can now understand and use the DWARF 2 debugging
5872 format. The choice is automatic, if the symbol file contains DWARF 2
5877 GDB now includes basic Java language support. This support is
5878 only useful with Java compilers that produce native machine code.
5880 * solib-absolute-prefix and solib-search-path
5882 For SunOS and SVR4 shared libraries, you may now set the prefix for
5883 loading absolute shared library symbol files, and the search path for
5884 locating non-absolute shared library symbol files.
5886 * Live range splitting
5888 GDB can now effectively debug code for which GCC has performed live
5889 range splitting as part of its optimization. See gdb/doc/LRS for
5890 more details on the expected format of the stabs information.
5894 GDB's support for the GNU Hurd, including thread debugging, has been
5895 updated to work with current versions of the Hurd.
5899 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5900 instruction set. ARM GDB automatically detects when Thumb
5901 instructions are in use, and adjusts disassembly and backtracing
5906 GDB's MIPS target configurations now handle the MIP16 16-bit
5911 GDB now includes support for overlays; if an executable has been
5912 linked such that multiple sections are based at the same address, GDB
5913 will decide which section to use for symbolic info. You can choose to
5914 control the decision manually, using overlay commands, or implement
5915 additional target-side support and use "overlay load-target" to bring
5916 in the overlay mapping. Do "help overlay" for more detail.
5920 The command "info symbol <address>" displays information about
5921 the symbol at the specified address.
5925 The standard remote protocol now includes an extension that allows
5926 asynchronous collection and display of trace data. This requires
5927 extensive support in the target-side debugging stub. Tracing mode
5928 includes a new interaction mode in GDB and new commands: see the
5929 file tracepoint.c for more details.
5933 Configurations for embedded MIPS now include a simulator contributed
5934 by Cygnus Solutions. The simulator supports the instruction sets
5935 of most MIPS variants.
5939 Sparc configurations may now include the ERC32 simulator contributed
5940 by the European Space Agency. The simulator is not built into
5941 Sparc targets by default; configure with --enable-sim to include it.
5945 For target configurations that may include multiple variants of a
5946 basic architecture (such as MIPS and SH), you may now set the
5947 architecture explicitly. "set arch" sets, "info arch" lists
5948 the possible architectures.
5950 *** Changes in GDB-4.16:
5952 * New native configurations
5954 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5955 M68K NetBSD m68k-*-netbsd*
5956 PowerPC AIX 4.x powerpc-*-aix*
5957 PowerPC MacOS powerpc-*-macos*
5958 PowerPC Windows NT powerpcle-*-cygwin32
5959 RS/6000 AIX 4.x rs6000-*-aix4*
5963 ARM with RDP protocol arm-*-*
5964 I960 with MON960 i960-*-coff
5965 MIPS VxWorks mips*-*-vxworks*
5966 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5967 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5969 Matra Sparclet sparclet-*-*
5973 The powerpc-eabi configuration now includes the PSIM simulator,
5974 contributed by Andrew Cagney, with assistance from Mike Meissner.
5975 PSIM is a very elaborate model of the PowerPC, including not only
5976 basic instruction set execution, but also details of execution unit
5977 performance and I/O hardware. See sim/ppc/README for more details.
5981 GDB now works with Solaris 2.5.
5983 * Windows 95/NT native
5985 GDB will now work as a native debugger on Windows 95 and Windows NT.
5986 To build it from source, you must use the "gnu-win32" environment,
5987 which uses a DLL to emulate enough of Unix to run the GNU tools.
5988 Further information, binaries, and sources are available at
5989 ftp.cygnus.com, under pub/gnu-win32.
5991 * dont-repeat command
5993 If a user-defined command includes the command `dont-repeat', then the
5994 command will not be repeated if the user just types return. This is
5995 useful if the command is time-consuming to run, so that accidental
5996 extra keystrokes don't run the same command many times.
5998 * Send break instead of ^C
6000 The standard remote protocol now includes an option to send a break
6001 rather than a ^C to the target in order to interrupt it. By default,
6002 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6004 * Remote protocol timeout
6006 The standard remote protocol includes a new variable `remotetimeout'
6007 that allows you to set the number of seconds before GDB gives up trying
6008 to read from the target. The default value is 2.
6010 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6012 By default GDB will automatically keep track of objects as they are
6013 loaded and unloaded by the dynamic linker. By using the command `set
6014 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6015 when shared library events occur, thus allowing you to set breakpoints
6016 in shared libraries which are explicitly loaded by the inferior.
6018 Note this feature does not work on hpux8. On hpux9 you must link
6019 /usr/lib/end.o into your program. This feature should work
6020 automatically on hpux10.
6022 * Irix 5.x hardware watchpoint support
6024 Irix 5 configurations now support the use of hardware watchpoints.
6026 * Mips protocol "SYN garbage limit"
6028 When debugging a Mips target using the `target mips' protocol, you
6029 may set the number of characters that GDB will ignore by setting
6030 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6031 every character. The default value is 1050.
6033 * Recording and replaying remote debug sessions
6035 If you set `remotelogfile' to the name of a file, gdb will write to it
6036 a recording of a remote debug session. This recording may then be
6037 replayed back to gdb using "gdbreplay". See gdbserver/README for
6038 details. This is useful when you have a problem with GDB while doing
6039 remote debugging; you can make a recording of the session and send it
6040 to someone else, who can then recreate the problem.
6042 * Speedups for remote debugging
6044 GDB includes speedups for downloading and stepping MIPS systems using
6045 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6046 and more efficient S-record downloading.
6048 * Memory use reductions and statistics collection
6050 GDB now uses less memory and reports statistics about memory usage.
6051 Try the `maint print statistics' command, for example.
6053 *** Changes in GDB-4.15:
6055 * Psymtabs for XCOFF
6057 The symbol reader for AIX GDB now uses partial symbol tables. This
6058 can greatly improve startup time, especially for large executables.
6060 * Remote targets use caching
6062 Remote targets now use a data cache to speed up communication with the
6063 remote side. The data cache could lead to incorrect results because
6064 it doesn't know about volatile variables, thus making it impossible to
6065 debug targets which use memory mapped I/O devices. `set remotecache
6066 off' turns the the data cache off.
6068 * Remote targets may have threads
6070 The standard remote protocol now includes support for multiple threads
6071 in the target system, using new protocol commands 'H' and 'T'. See
6072 gdb/remote.c for details.
6076 If GDB is configured with `--enable-netrom', then it will include
6077 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6078 acts as though it is a bank of ROM on the target board, but you can
6079 write into it over the network. GDB's support consists only of
6080 support for fast loading into the emulated ROM; to debug, you must use
6081 another protocol, such as standard remote protocol. The usual
6082 sequence is something like
6084 target nrom <netrom-hostname>
6086 target remote <netrom-hostname>:1235
6090 GDB now includes support for the Apple Macintosh, as a host only. It
6091 may be run as either an MPW tool or as a standalone application, and
6092 it can debug through the serial port. All the usual GDB commands are
6093 available, but to the target command, you must supply "serial" as the
6094 device type instead of "/dev/ttyXX". See mpw-README in the main
6095 directory for more information on how to build. The MPW configuration
6096 scripts */mpw-config.in support only a few targets, and only the
6097 mips-idt-ecoff target has been tested.
6101 GDB configuration now uses autoconf. This is not user-visible,
6102 but does simplify configuration and building.
6106 GDB now supports hpux10.
6108 *** Changes in GDB-4.14:
6110 * New native configurations
6112 x86 FreeBSD i[345]86-*-freebsd
6113 x86 NetBSD i[345]86-*-netbsd
6114 NS32k NetBSD ns32k-*-netbsd
6115 Sparc NetBSD sparc-*-netbsd
6119 A29K VxWorks a29k-*-vxworks
6120 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6121 CPU32 EST-300 emulator m68*-*-est*
6122 PowerPC ELF powerpc-*-elf
6125 * Alpha OSF/1 support for procfs
6127 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6128 possible to attach to running processes. As the mounting of the /proc
6129 filesystem is optional on the Alpha, GDB automatically determines
6130 the availability of /proc during startup. This can lead to problems
6131 if /proc is unmounted after GDB has been started.
6133 * Arguments to user-defined commands
6135 User commands may accept up to 10 arguments separated by whitespace.
6136 Arguments are accessed within the user command via $arg0..$arg9. A
6139 print $arg0 + $arg1 + $arg2
6141 To execute the command use:
6144 Defines the command "adder" which prints the sum of its three arguments.
6145 Note the arguments are text substitutions, so they may reference variables,
6146 use complex expressions, or even perform inferior function calls.
6148 * New `if' and `while' commands
6150 This makes it possible to write more sophisticated user-defined
6151 commands. Both commands take a single argument, which is the
6152 expression to evaluate, and must be followed by the commands to
6153 execute, one per line, if the expression is nonzero, the list being
6154 terminated by the word `end'. The `if' command list may include an
6155 `else' word, which causes the following commands to be executed only
6156 if the expression is zero.
6158 * Fortran source language mode
6160 GDB now includes partial support for Fortran 77. It will recognize
6161 Fortran programs and can evaluate a subset of Fortran expressions, but
6162 variables and functions may not be handled correctly. GDB will work
6163 with G77, but does not yet know much about symbols emitted by other
6166 * Better HPUX support
6168 Most debugging facilities now work on dynamic executables for HPPAs
6169 running hpux9 or later. You can attach to running dynamically linked
6170 processes, but by default the dynamic libraries will be read-only, so
6171 for instance you won't be able to put breakpoints in them. To change
6172 that behavior do the following before running the program:
6178 This will cause the libraries to be mapped private and read-write.
6179 To revert to the normal behavior, do this:
6185 You cannot set breakpoints or examine data in the library until after
6186 the library is loaded if the function/data symbols do not have
6189 GDB can now also read debug symbols produced by the HP C compiler on
6190 HPPAs (sorry, no C++, Fortran or 68k support).
6192 * Target byte order now dynamically selectable
6194 You can choose which byte order to use with a target system, via the
6195 commands "set endian big" and "set endian little", and you can see the
6196 current setting by using "show endian". You can also give the command
6197 "set endian auto", in which case GDB will use the byte order
6198 associated with the executable. Currently, only embedded MIPS
6199 configurations support dynamic selection of target byte order.
6201 * New DOS host serial code
6203 This version uses DPMI interrupts to handle buffered I/O, so you
6204 no longer need to run asynctsr when debugging boards connected to
6207 *** Changes in GDB-4.13:
6209 * New "complete" command
6211 This lists all the possible completions for the rest of the line, if it
6212 were to be given as a command itself. This is intended for use by emacs.
6214 * Trailing space optional in prompt
6216 "set prompt" no longer adds a space for you after the prompt you set. This
6217 allows you to set a prompt which ends in a space or one that does not.
6219 * Breakpoint hit counts
6221 "info break" now displays a count of the number of times the breakpoint
6222 has been hit. This is especially useful in conjunction with "ignore"; you
6223 can ignore a large number of breakpoint hits, look at the breakpoint info
6224 to see how many times the breakpoint was hit, then run again, ignoring one
6225 less than that number, and this will get you quickly to the last hit of
6228 * Ability to stop printing at NULL character
6230 "set print null-stop" will cause GDB to stop printing the characters of
6231 an array when the first NULL is encountered. This is useful when large
6232 arrays actually contain only short strings.
6234 * Shared library breakpoints
6236 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6237 breakpoints in shared libraries before the executable is run.
6239 * Hardware watchpoints
6241 There is a new hardware breakpoint for the watch command for sparclite
6242 targets. See gdb/sparclite/hw_breakpoint.note.
6244 Hardware watchpoints are also now supported under GNU/Linux.
6248 Annotations have been added. These are for use with graphical interfaces,
6249 and are still experimental. Currently only gdba.el uses these.
6251 * Improved Irix 5 support
6253 GDB now works properly with Irix 5.2.
6255 * Improved HPPA support
6257 GDB now works properly with the latest GCC and GAS.
6259 * New native configurations
6261 Sequent PTX4 i[34]86-sequent-ptx4
6262 HPPA running OSF/1 hppa*-*-osf*
6263 Atari TT running SVR4 m68*-*-sysv4*
6264 RS/6000 LynxOS rs6000-*-lynxos*
6268 OS/9000 i[34]86-*-os9k
6269 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6272 * Hitachi SH7000 and E7000-PC ICE support
6274 There is now support for communicating with the Hitachi E7000-PC ICE.
6275 This is available automatically when GDB is configured for the SH.
6279 As usual, a variety of small fixes and improvements, both generic
6280 and configuration-specific. See the ChangeLog for more detail.
6282 *** Changes in GDB-4.12:
6284 * Irix 5 is now supported
6288 GDB-4.12 on the HPPA has a number of changes which make it unable
6289 to debug the output from the currently released versions of GCC and
6290 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6291 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6292 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6295 *** Changes in GDB-4.11:
6297 * User visible changes:
6301 The "set remotedebug" option is now consistent between the mips remote
6302 target, remote targets using the gdb-specific protocol, UDI (AMD's
6303 debug protocol for the 29k) and the 88k bug monitor. It is now an
6304 integer specifying a debug level (normally 0 or 1, but 2 means more
6305 debugging info for the mips target).
6307 * DEC Alpha native support
6309 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6310 debug info, but GDB works fairly well with the DEC compiler and should
6311 work with a future GCC release. See the README file for a few
6312 Alpha-specific notes.
6314 * Preliminary thread implementation
6316 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6318 * LynxOS native and target support for 386
6320 This release has been hosted on LynxOS 2.2, and also can be configured
6321 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6324 * Improvements in C++ mangling/demangling.
6326 This release has much better g++ debugging, specifically in name
6327 mangling/demangling, virtual function calls, print virtual table,
6328 call methods, ...etc.
6330 *** Changes in GDB-4.10:
6332 * User visible changes:
6334 Remote debugging using the GDB-specific (`target remote') protocol now
6335 supports the `load' command. This is only useful if you have some
6336 other way of getting the stub to the target system, and you can put it
6337 somewhere in memory where it won't get clobbered by the download.
6339 Filename completion now works.
6341 When run under emacs mode, the "info line" command now causes the
6342 arrow to point to the line specified. Also, "info line" prints
6343 addresses in symbolic form (as well as hex).
6345 All vxworks based targets now support a user settable option, called
6346 vxworks-timeout. This option represents the number of seconds gdb
6347 should wait for responses to rpc's. You might want to use this if
6348 your vxworks target is, perhaps, a slow software simulator or happens
6349 to be on the far side of a thin network line.
6353 This release contains support for using a DEC alpha as a GDB host for
6354 cross debugging. Native alpha debugging is not supported yet.
6357 *** Changes in GDB-4.9:
6361 This is the first GDB release which is accompanied by a matching testsuite.
6362 The testsuite requires installation of dejagnu, which should be available
6363 via ftp from most sites that carry GNU software.
6367 'Cfront' style demangling has had its name changed to 'ARM' style, to
6368 emphasize that it was written from the specifications in the C++ Annotated
6369 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6370 disclaimers, it still generated too much confusion with users attempting to
6371 use gdb with AT&T cfront.
6375 GDB now uses a standard remote interface to a simulator library.
6376 So far, the library contains simulators for the Zilog Z8001/2, the
6377 Hitachi H8/300, H8/500 and Super-H.
6379 * New targets supported
6381 H8/300 simulator h8300-hitachi-hms or h8300hms
6382 H8/500 simulator h8500-hitachi-hms or h8500hms
6383 SH simulator sh-hitachi-hms or sh
6384 Z8000 simulator z8k-zilog-none or z8ksim
6385 IDT MIPS board over serial line mips-idt-ecoff
6387 Cross-debugging to GO32 targets is supported. It requires a custom
6388 version of the i386-stub.c module which is integrated with the
6389 GO32 memory extender.
6391 * New remote protocols
6393 MIPS remote debugging protocol.
6395 * New source languages supported
6397 This version includes preliminary support for Chill, a Pascal like language
6398 used by telecommunications companies. Chill support is also being integrated
6399 into the GNU compiler, but we don't know when it will be publically available.
6402 *** Changes in GDB-4.8:
6404 * HP Precision Architecture supported
6406 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6407 version of this support was available as a set of patches from the
6408 University of Utah. GDB does not support debugging of programs
6409 compiled with the HP compiler, because HP will not document their file
6410 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6411 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6413 Many problems in the preliminary version have been fixed.
6415 * Faster and better demangling
6417 We have improved template demangling and fixed numerous bugs in the GNU style
6418 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6419 character types (wchar_t) are now supported. Demangling of each symbol is now
6420 only done once, and is cached when the symbol table for a file is read in.
6421 This results in a small increase in memory usage for C programs, a moderate
6422 increase in memory usage for C++ programs, and a fantastic speedup in
6425 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6426 from the specifications in the Annotated Reference Manual, which AT&T's
6427 compiler does not actually implement.
6429 * G++ multiple inheritance compiler problem
6431 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6432 inheritance lattices was reworked to properly discover ambiguities. We
6433 recently found an example which causes this new algorithm to fail in a
6434 very subtle way, producing bad debug information for those classes.
6435 The file 'gcc.patch' (in this directory) can be applied to gcc to
6436 circumvent the problem. A future GCC release will contain a complete
6439 The previous G++ debug info problem (mentioned below for the gdb-4.7
6440 release) is fixed in gcc version 2.3.2.
6442 * Improved configure script
6444 The `configure' script will now attempt to guess your system type if
6445 you don't supply a host system type. The old scheme of supplying a
6446 host system triplet is preferable over using this. All the magic is
6447 done in the new `config.guess' script. Examine it for details.
6449 We have also brought our configure script much more in line with the FSF's
6450 version. It now supports the --with-xxx options. In particular,
6451 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6452 The resulting GDB will not be able to read arbitrary object file formats --
6453 only the format ``expected'' to be used on the configured target system.
6454 We hope to make this the default in a future release.
6456 * Documentation improvements
6458 There's new internal documentation on how to modify GDB, and how to
6459 produce clean changes to the code. We implore people to read it
6460 before submitting changes.
6462 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6463 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6464 `info' files are also provided. To build `info' files from scratch,
6465 you will need the latest `makeinfo' release, which will be available in
6466 a future texinfo-X.Y release.
6468 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6469 We're not sure exactly which versions have this problem, but it has
6470 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6471 or better. If that isn't possible, there is a patch in
6472 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6473 around this problem.
6477 GDB now supports array constants that can be used in expressions typed in by
6478 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6479 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6482 The new directory `gdb/sparclite' contains a program that demonstrates
6483 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6485 * New native hosts supported
6487 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6488 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6490 * New targets supported
6492 AMD 29k family via UDI a29k-amd-udi or udi29k
6494 * New file formats supported
6496 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6497 HPUX core files, and SCO 3.2v2 core files.
6501 Attaching to processes now works again; thanks for the many bug reports.
6503 We have also stomped on a bunch of core dumps caused by
6504 printf_filtered("%s") problems.
6506 We eliminated a copyright problem on the rpc and ptrace header files
6507 for VxWorks, which was discovered at the last minute during the 4.7
6508 release. You should now be able to build a VxWorks GDB.
6510 You can now interrupt gdb while an attached process is running. This
6511 will cause the attached process to stop, and give control back to GDB.
6513 We fixed problems caused by using too many file descriptors
6514 for reading symbols from object files and libraries. This was
6515 especially a problem for programs that used many (~100) shared
6518 The `step' command now only enters a subroutine if there is line number
6519 information for the subroutine. Otherwise it acts like the `next'
6520 command. Previously, `step' would enter subroutines if there was
6521 any debugging information about the routine. This avoids problems
6522 when using `cc -g1' on MIPS machines.
6524 * Internal improvements
6526 GDB's internal interfaces have been improved to make it easier to support
6527 debugging of multiple languages in the future.
6529 GDB now uses a common structure for symbol information internally.
6530 Minimal symbols (derived from linkage symbols in object files), partial
6531 symbols (from a quick scan of debug information), and full symbols
6532 contain a common subset of information, making it easier to write
6533 shared code that handles any of them.
6535 * New command line options
6537 We now accept --silent as an alias for --quiet.
6541 The memory-mapped-malloc library is now licensed under the GNU Library
6542 General Public License.
6544 *** Changes in GDB-4.7:
6546 * Host/native/target split
6548 GDB has had some major internal surgery to untangle the support for
6549 hosts and remote targets. Now, when you configure GDB for a remote
6550 target, it will no longer load in all of the support for debugging
6551 local programs on the host. When fully completed and tested, this will
6552 ensure that arbitrary host/target combinations are possible.
6554 The primary conceptual shift is to separate the non-portable code in
6555 GDB into three categories. Host specific code is required any time GDB
6556 is compiled on that host, regardless of the target. Target specific
6557 code relates to the peculiarities of the target, but can be compiled on
6558 any host. Native specific code is everything else: it can only be
6559 built when the host and target are the same system. Child process
6560 handling and core file support are two common `native' examples.
6562 GDB's use of /proc for controlling Unix child processes is now cleaner.
6563 It has been split out into a single module under the `target_ops' vector,
6564 plus two native-dependent functions for each system that uses /proc.
6566 * New hosts supported
6568 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6569 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6570 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6572 * New targets supported
6574 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6575 68030 and CPU32 m68030-*-*, m68332-*-*
6577 * New native hosts supported
6579 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6580 (386bsd is not well tested yet)
6581 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6583 * New file formats supported
6585 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6586 supports reading of `a.out.adobe' object files, which are an a.out
6587 format extended with minimal information about multiple sections.
6591 `show copying' is the same as the old `info copying'.
6592 `show warranty' is the same as `info warrantee'.
6593 These were renamed for consistency. The old commands continue to work.
6595 `info handle' is a new alias for `info signals'.
6597 You can now define pre-command hooks, which attach arbitrary command
6598 scripts to any command. The commands in the hook will be executed
6599 prior to the user's command. You can also create a hook which will be
6600 executed whenever the program stops. See gdb.texinfo.
6604 We now deal with Cfront style name mangling, and can even extract type
6605 info from mangled symbols. GDB can automatically figure out which
6606 symbol mangling style your C++ compiler uses.
6608 Calling of methods and virtual functions has been improved as well.
6612 The crash that occured when debugging Sun Ansi-C compiled binaries is
6613 fixed. This was due to mishandling of the extra N_SO stabs output
6616 We also finally got Ultrix 4.2 running in house, and fixed core file
6617 support, with help from a dozen people on the net.
6619 John M. Farrell discovered that the reason that single-stepping was so
6620 slow on all of the Mips based platforms (primarily SGI and DEC) was
6621 that we were trying to demangle and lookup a symbol used for internal
6622 purposes on every instruction that was being stepped through. Changing
6623 the name of that symbol so that it couldn't be mistaken for a C++
6624 mangled symbol sped things up a great deal.
6626 Rich Pixley sped up symbol lookups in general by getting much smarter
6627 about when C++ symbol mangling is necessary. This should make symbol
6628 completion (TAB on the command line) much faster. It's not as fast as
6629 we'd like, but it's significantly faster than gdb-4.6.
6633 A new user controllable variable 'call_scratch_address' can
6634 specify the location of a scratch area to be used when GDB
6635 calls a function in the target. This is necessary because the
6636 usual method of putting the scratch area on the stack does not work
6637 in systems that have separate instruction and data spaces.
6639 We integrated changes to support the 29k UDI (Universal Debugger
6640 Interface), but discovered at the last minute that we didn't have all
6641 of the appropriate copyright paperwork. We are working with AMD to
6642 resolve this, and hope to have it available soon.
6646 We have sped up the remote serial line protocol, especially for targets
6647 with lots of registers. It now supports a new `expedited status' ('T')
6648 message which can be used in place of the existing 'S' status message.
6649 This allows the remote stub to send only the registers that GDB
6650 needs to make a quick decision about single-stepping or conditional
6651 breakpoints, eliminating the need to fetch the entire register set for
6652 each instruction being stepped through.
6654 The GDB remote serial protocol now implements a write-through cache for
6655 registers, only re-reading the registers if the target has run.
6657 There is also a new remote serial stub for SPARC processors. You can
6658 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6659 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6660 processor with a serial port.
6664 Configure.in files have become much easier to read and modify. A new
6665 `table driven' format makes it more obvious what configurations are
6666 supported, and what files each one uses.
6670 There is a new opcodes library which will eventually contain all of the
6671 disassembly routines and opcode tables. At present, it only contains
6672 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6673 disassembler (binutils/objdump) to share these routines.
6675 The libiberty library is now copylefted under the GNU Library General
6676 Public License. This allows more liberal use, and was done so libg++
6677 can use it. This makes no difference to GDB, since the Library License
6678 grants all the rights from the General Public License.
6682 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6683 reference to the stabs symbol info used by the debugger. It is (as far
6684 as we know) the only published document on this fascinating topic. We
6685 encourage you to read it, compare it to the stabs information on your
6686 system, and send improvements on the document in general (to
6687 bug-gdb@prep.ai.mit.edu).
6689 And, of course, many bugs have been fixed.
6692 *** Changes in GDB-4.6:
6694 * Better support for C++ function names
6696 GDB now accepts as input the "demangled form" of C++ overloaded function
6697 names and member function names, and can do command completion on such names
6698 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6699 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6700 Make use of command completion, it is your friend.
6702 GDB also now accepts a variety of C++ mangled symbol formats. They are
6703 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6704 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6705 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6706 for the list of formats.
6708 * G++ symbol mangling problem
6710 Recent versions of gcc have a bug in how they emit debugging information for
6711 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6712 directory) can be applied to gcc to fix the problem. Alternatively, if you
6713 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6714 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6715 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6718 * New 'maintenance' command
6720 All of the commands related to hacking GDB internals have been moved out of
6721 the main command set, and now live behind the 'maintenance' command. This
6722 can also be abbreviated as 'mt'. The following changes were made:
6724 dump-me -> maintenance dump-me
6725 info all-breakpoints -> maintenance info breakpoints
6726 printmsyms -> maintenance print msyms
6727 printobjfiles -> maintenance print objfiles
6728 printpsyms -> maintenance print psymbols
6729 printsyms -> maintenance print symbols
6731 The following commands are new:
6733 maintenance demangle Call internal GDB demangler routine to
6734 demangle a C++ link name and prints the result.
6735 maintenance print type Print a type chain for a given symbol
6737 * Change to .gdbinit file processing
6739 We now read the $HOME/.gdbinit file before processing the argv arguments
6740 (e.g. reading symbol files or core files). This allows global parameters to
6741 be set, which will apply during the symbol reading. The ./.gdbinit is still
6742 read after argv processing.
6744 * New hosts supported
6746 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6748 GNU/Linux support i386-unknown-linux or linux
6750 We are also including code to support the HP/PA running BSD and HPUX. This
6751 is almost guaranteed not to work, as we didn't have time to test or build it
6752 for this release. We are including it so that the more adventurous (or
6753 masochistic) of you can play with it. We also had major problems with the
6754 fact that the compiler that we got from HP doesn't support the -g option.
6757 * New targets supported
6759 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6761 * More smarts about finding #include files
6763 GDB now remembers the compilation directory for all include files, and for
6764 all files from which C is generated (like yacc and lex sources). This
6765 greatly improves GDB's ability to find yacc/lex sources, and include files,
6766 especially if you are debugging your program from a directory different from
6767 the one that contains your sources.
6769 We also fixed a bug which caused difficulty with listing and setting
6770 breakpoints in include files which contain C code. (In the past, you had to
6771 try twice in order to list an include file that you hadn't looked at before.)
6773 * Interesting infernals change
6775 GDB now deals with arbitrary numbers of sections, where the symbols for each
6776 section must be relocated relative to that section's landing place in the
6777 target's address space. This work was needed to support ELF with embedded
6778 stabs used by Solaris-2.0.
6780 * Bug fixes (of course!)
6782 There have been loads of fixes for the following things:
6783 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6784 i960, stabs, DOS(GO32), procfs, etc...
6786 See the ChangeLog for details.
6788 *** Changes in GDB-4.5:
6790 * New machines supported (host and target)
6792 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6794 SGI Irix-4.x mips-sgi-irix4 or iris4
6796 * New malloc package
6798 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6799 Mmalloc is capable of handling mutiple heaps of memory. It is also
6800 capable of saving a heap to a file, and then mapping it back in later.
6801 This can be used to greatly speedup the startup of GDB by using a
6802 pre-parsed symbol table which lives in a mmalloc managed heap. For
6803 more details, please read mmalloc/mmalloc.texi.
6807 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6808 'help info proc' for details.
6810 * MIPS ecoff symbol table format
6812 The code that reads MIPS symbol table format is now supported on all hosts.
6813 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6816 * File name changes for MS-DOS
6818 Many files in the config directories have been renamed to make it easier to
6819 support GDB on MS-DOSe systems (which have very restrictive file name
6820 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6821 environment) is close to working but has some remaining problems. Note
6822 that debugging of DOS programs is not supported, due to limitations
6823 in the ``operating system'', but it can be used to host cross-debugging.
6825 * Cross byte order fixes
6827 Many fixes have been made to support cross debugging of Sparc and MIPS
6828 targets from hosts whose byte order differs.
6830 * New -mapped and -readnow options
6832 If memory-mapped files are available on your system through the 'mmap'
6833 system call, you can use the -mapped option on the `file' or
6834 `symbol-file' commands to cause GDB to write the symbols from your
6835 program into a reusable file. If the program you are debugging is
6836 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6837 Future GDB debugging sessions will notice the presence of this file,
6838 and will quickly map in symbol information from it, rather than reading
6839 the symbol table from the executable program. Using the '-mapped'
6840 option in a GDB `file' or `symbol-file' command has the same effect as
6841 starting GDB with the '-mapped' command-line option.
6843 You can cause GDB to read the entire symbol table immediately by using
6844 the '-readnow' option with any of the commands that load symbol table
6845 information (or on the GDB command line). This makes the command
6846 slower, but makes future operations faster.
6848 The -mapped and -readnow options are typically combined in order to
6849 build a `fred.syms' file that contains complete symbol information.
6850 A simple GDB invocation to do nothing but build a `.syms' file for future
6853 gdb -batch -nx -mapped -readnow programname
6855 The `.syms' file is specific to the host machine on which GDB is run.
6856 It holds an exact image of GDB's internal symbol table. It cannot be
6857 shared across multiple host platforms.
6859 * longjmp() handling
6861 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6862 siglongjmp() without losing control. This feature has not yet been ported to
6863 all systems. It currently works on many 386 platforms, all MIPS-based
6864 platforms (SGI, DECstation, etc), and Sun3/4.
6868 Preliminary work has been put in to support the new Solaris OS from Sun. At
6869 this time, it can control and debug processes, but it is not capable of
6874 As always, many many bug fixes. The major areas were with g++, and mipsread.
6875 People using the MIPS-based platforms should experience fewer mysterious
6876 crashes and trashed symbol tables.
6878 *** Changes in GDB-4.4:
6880 * New machines supported (host and target)
6882 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6884 BSD Reno on Vax vax-dec-bsd
6885 Ultrix on Vax vax-dec-ultrix
6887 * New machines supported (target)
6889 AMD 29000 embedded, using EBMON a29k-none-none
6893 GDB continues to improve its handling of C++. `References' work better.
6894 The demangler has also been improved, and now deals with symbols mangled as
6895 per the Annotated C++ Reference Guide.
6897 GDB also now handles `stabs' symbol information embedded in MIPS
6898 `ecoff' symbol tables. Since the ecoff format was not easily
6899 extensible to handle new languages such as C++, this appeared to be a
6900 good way to put C++ debugging info into MIPS binaries. This option
6901 will be supported in the GNU C compiler, version 2, when it is
6904 * New features for SVR4
6906 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6907 shared libraries. Debugging dynamically linked programs should present
6908 only minor differences from debugging statically linked programs.
6910 The `info proc' command will print out information about any process
6911 on an SVR4 system (including the one you are debugging). At the moment,
6912 it prints the address mappings of the process.
6914 If you bring up GDB on another SVR4 system, please send mail to
6915 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6917 * Better dynamic linking support in SunOS
6919 Reading symbols from shared libraries which contain debugging symbols
6920 now works properly. However, there remain issues such as automatic
6921 skipping of `transfer vector' code during function calls, which
6922 make it harder to debug code in a shared library, than to debug the
6923 same code linked statically.
6927 GDB is now using the latest `getopt' routines from the FSF. This
6928 version accepts the -- prefix for options with long names. GDB will
6929 continue to accept the old forms (-option and +option) as well.
6930 Various single letter abbreviations for options have been explicity
6931 added to the option table so that they won't get overshadowed in the
6932 future by other options that begin with the same letter.
6936 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6937 Many assorted bugs have been handled. Many more remain to be handled.
6938 See the various ChangeLog files (primarily in gdb and bfd) for details.
6941 *** Changes in GDB-4.3:
6943 * New machines supported (host and target)
6945 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6946 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6947 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6949 * Almost SCO Unix support
6951 We had hoped to support:
6952 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6953 (except for core file support), but we discovered very late in the release
6954 that it has problems with process groups that render gdb unusable. Sorry
6955 about that. I encourage people to fix it and post the fixes.
6957 * Preliminary ELF and DWARF support
6959 GDB can read ELF object files on System V Release 4, and can handle
6960 debugging records for C, in DWARF format, in ELF files. This support
6961 is preliminary. If you bring up GDB on another SVR4 system, please
6962 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6967 GDB now uses the latest `readline' library. One user-visible change
6968 is that two tabs will list possible command completions, which previously
6969 required typing M-? (meta-question mark, or ESC ?).
6973 The `stepi' bug that many of you noticed has been squashed.
6974 Many bugs in C++ have been handled. Many more remain to be handled.
6975 See the various ChangeLog files (primarily in gdb and bfd) for details.
6977 * State of the MIPS world (in case you wondered):
6979 GDB can understand the symbol tables emitted by the compilers
6980 supplied by most vendors of MIPS-based machines, including DEC. These
6981 symbol tables are in a format that essentially nobody else uses.
6983 Some versions of gcc come with an assembler post-processor called
6984 mips-tfile. This program is required if you want to do source-level
6985 debugging of gcc-compiled programs. I believe FSF does not ship
6986 mips-tfile with gcc version 1, but it will eventually come with gcc
6989 Debugging of g++ output remains a problem. g++ version 1.xx does not
6990 really support it at all. (If you're lucky, you should be able to get
6991 line numbers and stack traces to work, but no parameters or local
6992 variables.) With some work it should be possible to improve the
6995 When gcc version 2 is released, you will have somewhat better luck.
6996 However, even then you will get confusing results for inheritance and
6999 We will eventually provide full debugging of g++ output on
7000 DECstations. This will probably involve some kind of stabs-in-ecoff
7001 encapulation, but the details have not been worked out yet.
7004 *** Changes in GDB-4.2:
7006 * Improved configuration
7008 Only one copy of `configure' exists now, and it is not self-modifying.
7009 Porting BFD is simpler.
7013 The `step' and `next' commands now only stop at the first instruction
7014 of a source line. This prevents the multiple stops that used to occur
7015 in switch statements, for-loops, etc. `Step' continues to stop if a
7016 function that has debugging information is called within the line.
7020 Lots of small bugs fixed. More remain.
7022 * New host supported (not target)
7024 Intel 386 PC clone running Mach i386-none-mach
7027 *** Changes in GDB-4.1:
7029 * Multiple source language support
7031 GDB now has internal scaffolding to handle several source languages.
7032 It determines the type of each source file from its filename extension,
7033 and will switch expression parsing and number formatting to match the
7034 language of the function in the currently selected stack frame.
7035 You can also specifically set the language to be used, with
7036 `set language c' or `set language modula-2'.
7040 GDB now has preliminary support for the GNU Modula-2 compiler,
7041 currently under development at the State University of New York at
7042 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7043 continue through the fall of 1991 and into 1992.
7045 Other Modula-2 compilers are currently not supported, and attempting to
7046 debug programs compiled with them will likely result in an error as the
7047 symbol table is read. Feel free to work on it, though!
7049 There are hooks in GDB for strict type checking and range checking,
7050 in the `Modula-2 philosophy', but they do not currently work.
7054 GDB can now write to executable and core files (e.g. patch
7055 a variable's value). You must turn this switch on, specify
7056 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7057 by assigning a new value to a variable. Modifications take
7060 * Automatic SunOS shared library reading
7062 When you run your program, GDB automatically determines where its
7063 shared libraries (if any) have been loaded, and reads their symbols.
7064 The `share' command is no longer needed. This also works when
7065 examining core files.
7069 You can specify the number of lines that the `list' command shows.
7072 * New machines supported (host and target)
7074 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7075 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7076 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7078 * New hosts supported (not targets)
7080 IBM RT/PC: romp-ibm-aix or rtpc
7082 * New targets supported (not hosts)
7084 AMD 29000 embedded with COFF a29k-none-coff
7085 AMD 29000 embedded with a.out a29k-none-aout
7086 Ultracomputer remote kernel debug a29k-nyu-kern
7088 * New remote interfaces
7094 *** Changes in GDB-4.0:
7098 Wide output is wrapped at good places to make the output more readable.
7100 Gdb now supports cross-debugging from a host machine of one type to a
7101 target machine of another type. Communication with the target system
7102 is over serial lines. The ``target'' command handles connecting to the
7103 remote system; the ``load'' command will download a program into the
7104 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7105 also supports debugging of realtime processes running under VxWorks,
7106 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7107 stub on the target system.
7109 New CPUs supported include the AMD 29000 and Intel 960.
7111 GDB now reads object files and symbol tables via a ``binary file''
7112 library, which allows a single copy of GDB to debug programs of multiple
7113 object file types such as a.out and coff.
7115 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7116 refcard.dvi and refcard.ps are available to format it).
7119 * Control-Variable user interface simplified
7121 All variables that control the operation of the debugger can be set
7122 by the ``set'' command, and displayed by the ``show'' command.
7124 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7125 ``Show prompt'' produces the response:
7126 Gdb's prompt is new-gdb=>.
7128 What follows are the NEW set commands. The command ``help set'' will
7129 print a complete list of old and new set commands. ``help set FOO''
7130 will give a longer description of the variable FOO. ``show'' will show
7131 all of the variable descriptions and their current settings.
7133 confirm on/off: Enables warning questions for operations that are
7134 hard to recover from, e.g. rerunning the program while
7135 it is already running. Default is ON.
7137 editing on/off: Enables EMACS style command line editing
7138 of input. Previous lines can be recalled with
7139 control-P, the current line can be edited with control-B,
7140 you can search for commands with control-R, etc.
7143 history filename NAME: NAME is where the gdb command history
7144 will be stored. The default is .gdb_history,
7145 or the value of the environment variable
7148 history size N: The size, in commands, of the command history. The
7149 default is 256, or the value of the environment variable
7152 history save on/off: If this value is set to ON, the history file will
7153 be saved after exiting gdb. If set to OFF, the
7154 file will not be saved. The default is OFF.
7156 history expansion on/off: If this value is set to ON, then csh-like
7157 history expansion will be performed on
7158 command line input. The default is OFF.
7160 radix N: Sets the default radix for input and output. It can be set
7161 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7162 in the current radix, so "set radix 10" is always a no-op.
7164 height N: This integer value is the number of lines on a page. Default
7165 is 24, the current `stty rows'' setting, or the ``li#''
7166 setting from the termcap entry matching the environment
7169 width N: This integer value is the number of characters on a line.
7170 Default is 80, the current `stty cols'' setting, or the ``co#''
7171 setting from the termcap entry matching the environment
7174 Note: ``set screensize'' is obsolete. Use ``set height'' and
7175 ``set width'' instead.
7177 print address on/off: Print memory addresses in various command displays,
7178 such as stack traces and structure values. Gdb looks
7179 more ``symbolic'' if you turn this off; it looks more
7180 ``machine level'' with it on. Default is ON.
7182 print array on/off: Prettyprint arrays. New convenient format! Default
7185 print demangle on/off: Print C++ symbols in "source" form if on,
7188 print asm-demangle on/off: Same, for assembler level printouts
7191 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7194 * Support for Epoch Environment.
7196 The epoch environment is a version of Emacs v18 with windowing. One
7197 new command, ``inspect'', is identical to ``print'', except that if you
7198 are running in the epoch environment, the value is printed in its own
7202 * Support for Shared Libraries
7204 GDB can now debug programs and core files that use SunOS shared libraries.
7205 Symbols from a shared library cannot be referenced
7206 before the shared library has been linked with the program (this
7207 happens after you type ``run'' and before the function main() is entered).
7208 At any time after this linking (including when examining core files
7209 from dynamically linked programs), gdb reads the symbols from each
7210 shared library when you type the ``sharedlibrary'' command.
7211 It can be abbreviated ``share''.
7213 sharedlibrary REGEXP: Load shared object library symbols for files
7214 matching a unix regular expression. No argument
7215 indicates to load symbols for all shared libraries.
7217 info sharedlibrary: Status of loaded shared libraries.
7222 A watchpoint stops execution of a program whenever the value of an
7223 expression changes. Checking for this slows down execution
7224 tremendously whenever you are in the scope of the expression, but is
7225 quite useful for catching tough ``bit-spreader'' or pointer misuse
7226 problems. Some machines such as the 386 have hardware for doing this
7227 more quickly, and future versions of gdb will use this hardware.
7229 watch EXP: Set a watchpoint (breakpoint) for an expression.
7231 info watchpoints: Information about your watchpoints.
7233 delete N: Deletes watchpoint number N (same as breakpoints).
7234 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7235 enable N: Re-enables watchpoint number N (same as breakpoints).
7238 * C++ multiple inheritance
7240 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7243 * C++ exception handling
7245 Gdb now supports limited C++ exception handling. Besides the existing
7246 ability to breakpoint on an exception handler, gdb can breakpoint on
7247 the raising of an exception (before the stack is peeled back to the
7250 catch FOO: If there is a FOO exception handler in the dynamic scope,
7251 set a breakpoint to catch exceptions which may be raised there.
7252 Multiple exceptions (``catch foo bar baz'') may be caught.
7254 info catch: Lists all exceptions which may be caught in the
7255 current stack frame.
7258 * Minor command changes
7260 The command ``call func (arg, arg, ...)'' now acts like the print
7261 command, except it does not print or save a value if the function's result
7262 is void. This is similar to dbx usage.
7264 The ``up'' and ``down'' commands now always print the frame they end up
7265 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7266 frames without printing.
7268 * New directory command
7270 'dir' now adds directories to the FRONT of the source search path.
7271 The path starts off empty. Source files that contain debug information
7272 about the directory in which they were compiled can be found even
7273 with an empty path; Sun CC and GCC include this information. If GDB can't
7274 find your source file in the current directory, type "dir .".
7276 * Configuring GDB for compilation
7278 For normal use, type ``./configure host''. See README or gdb.texinfo
7281 GDB now handles cross debugging. If you are remotely debugging between
7282 two different machines, type ``./configure host -target=targ''.
7283 Host is the machine where GDB will run; targ is the machine
7284 where the program that you are debugging will run.