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
60 set debug compile-cplus-types
61 show debug compile-cplus-types
62 Control the display of debug output about type conversion in the
63 C++ compile feature. Commands have no effect while compiliong
68 Control whether debug output about files/functions skipping is
71 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
72 Apply a command to some frames.
73 FLAG arguments allow to control what output to produce and how to handle
74 errors raised when applying COMMAND to a frame.
77 Apply a command to all threads (ignoring errors and empty output).
78 Shortcut for 'thread apply all -s COMMAND'.
81 Apply a command to all frames (ignoring errors and empty output).
82 Shortcut for 'frame apply all -s COMMAND'.
85 Apply a command to all frames of all threads (ignoring errors and empty
87 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
89 maint set dwarf unwinders (on|off)
90 maint show dwarf unwinders
91 Control whether DWARF unwinders can be used.
94 Display a list of open files for a process.
98 Changes to the "frame", "select-frame", and "info frame" CLI commands.
99 These commands all now take a frame specification which
100 is either a frame level, or one of the keywords 'level', 'address',
101 'function', or 'view' followed by a parameter. Selecting a frame by
102 address, or viewing a frame outside the current backtrace now
103 requires the use of a keyword. Selecting a frame by level is
104 unchanged. The MI comment "-stack-select-frame" is unchanged.
106 target remote FILENAME
107 target extended-remote FILENAME
108 If FILENAME is a Unix domain socket, GDB will attempt to connect
109 to this socket instead of opening FILENAME as a character device.
111 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
112 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
113 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
114 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
115 These commands can now print only the searched entities
116 matching the provided regexp(s), giving a condition
117 on the entity names or entity types. The flag -q disables
118 printing headers or informations messages.
124 These commands now determine the syntax for the shown entities
125 according to the language chosen by `set language'. In particular,
126 `set language auto' means to automatically choose the language of
129 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
130 The 'thread apply' command accepts new FLAG arguments.
131 FLAG arguments allow to control what output to produce and how to handle
132 errors raised when applying COMMAND to a thread.
134 set tui tab-width NCHARS
135 show tui tab-width NCHARS
136 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
138 set style enabled [on|off]
140 Enable or disable terminal styling. Styling is enabled by default
141 on most hosts, but disabled by default when in batch mode.
143 set style filename foreground COLOR
144 set style filename background COLOR
145 set style filename intensity VALUE
146 Control the styling of file names.
148 set style function foreground COLOR
149 set style function background COLOR
150 set style function intensity VALUE
151 Control the styling of function names.
153 set style variable foreground COLOR
154 set style variable background COLOR
155 set style variable intensity VALUE
156 Control the styling of variable names.
158 set style address foreground COLOR
159 set style address background COLOR
160 set style address intensity VALUE
161 Control the styling of addresses.
165 ** The '-data-disassemble' MI command now accepts an '-a' option to
166 disassemble the whole function surrounding the given program
167 counter value or function name. Support for this feature can be
168 verified by using the "-list-features" command, which should
169 contain "data-disassemble-a-option".
171 ** Command responses and notifications that include a frame now include
172 the frame's architecture in a new "arch" attribute.
174 * New native configurations
176 GNU/Linux/RISC-V riscv*-*-linux*
177 FreeBSD/riscv riscv*-*-freebsd*
181 GNU/Linux/RISC-V riscv*-*-linux*
183 CSKY GNU/LINUX csky*-*-linux
184 FreeBSD/riscv riscv*-*-freebsd*
186 GNU/Linux/OpenRISC or1k*-*-linux*
190 GDB no longer supports native debugging on versions of MS-Windows
195 ** GDB no longer supports Python versions less than 2.6.
197 ** The gdb.Inferior type has a new 'progspace' property, which is the program
198 space associated to that inferior.
200 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
201 of objfiles associated to that program space.
203 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
204 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
207 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
208 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
209 correct and did not work properly.
211 ** The gdb.Value type has a new constructor, which is used to construct a
212 gdb.Value from a Python buffer object and a gdb.Type.
218 Enable or disable the undefined behavior sanitizer. This is
219 disabled by default, but passing --enable-ubsan=yes or
220 --enable-ubsan=auto to configure will enable it. Enabling this can
221 cause a performance penalty. The undefined behavior sanitizer was
222 first introduced in GCC 4.9.
224 *** Changes in GDB 8.2
226 * The 'set disassembler-options' command now supports specifying options
229 * The 'symbol-file' command now accepts an '-o' option to add a relative
230 offset to all sections.
232 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
233 a relative offset to all sections, but it allows to override the load
234 address of individual sections using '-s'.
236 * The 'add-symbol-file' command no longer requires the second argument
237 (address of the text section).
239 * The endianness used with the 'set endian auto' mode in the absence of
240 an executable selected for debugging is now the last endianness chosen
241 either by one of the 'set endian big' and 'set endian little' commands
242 or by inferring from the last executable used, rather than the startup
245 * The pager now allows a "c" response, meaning to disable the pager
246 for the rest of the current command.
248 * The commands 'info variables/functions/types' now show the source line
249 numbers of symbol definitions when available.
251 * 'info proc' now works on running processes on FreeBSD systems and core
252 files created on FreeBSD systems.
254 * C expressions can now use _Alignof, and C++ expressions can now use
257 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
258 the vector length while the process is running.
264 Control display of debugging info regarding the FreeBSD native target.
266 set|show varsize-limit
267 This new setting allows the user to control the maximum size of Ada
268 objects being printed when those objects have a variable type,
269 instead of that maximum size being hardcoded to 65536 bytes.
271 set|show record btrace cpu
272 Controls the processor to be used for enabling errata workarounds for
275 maint check libthread-db
276 Run integrity checks on the current inferior's thread debugging
279 maint set check-libthread-db (on|off)
280 maint show check-libthread-db
281 Control whether to run integrity checks on inferior specific thread
282 debugging libraries as they are loaded. The default is not to
287 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
289 ** The commands attached to a breakpoint can be set by assigning to
290 the breakpoint's "commands" field.
292 ** gdb.execute can now execute multi-line gdb commands.
294 ** The new functions gdb.convenience_variable and
295 gdb.set_convenience_variable can be used to get and set the value
296 of convenience variables.
298 ** A gdb.Parameter will no longer print the "set" help text on an
299 ordinary "set"; instead by default a "set" will be silent unless
300 the get_set_string method returns a non-empty string.
304 RiscV ELF riscv*-*-elf
306 * Removed targets and native configurations
308 m88k running OpenBSD m88*-*-openbsd*
309 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
310 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
311 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
313 * Aarch64/Linux hardware watchpoints improvements
315 Hardware watchpoints on unaligned addresses are now properly
316 supported when running Linux kernel 4.10 or higher: read and access
317 watchpoints are no longer spuriously missed, and all watchpoints
318 lengths between 1 and 8 bytes are supported. On older kernels,
319 watchpoints set on unaligned addresses are no longer missed, with
320 the tradeoff that there is a possibility of false hits being
325 --enable-codesign=CERT
326 This can be used to invoke "codesign -s CERT" after building gdb.
327 This option is useful on macOS, where code signing is required for
328 gdb to work properly.
330 --disable-gdbcli has been removed
331 This is now silently accepted, but does nothing.
333 *** Changes in GDB 8.1
335 * GDB now supports dynamically creating arbitrary register groups specified
336 in XML target descriptions. This allows for finer grain grouping of
337 registers on systems with a large amount of registers.
339 * The 'ptype' command now accepts a '/o' flag, which prints the
340 offsets and sizes of fields in a struct, like the pahole(1) tool.
342 * New "--readnever" command line option instructs GDB to not read each
343 symbol file's symbolic debug information. This makes startup faster
344 but at the expense of not being able to perform symbolic debugging.
345 This option is intended for use cases where symbolic debugging will
346 not be used, e.g., when you only need to dump the debuggee's core.
348 * GDB now uses the GNU MPFR library, if available, to emulate target
349 floating-point arithmetic during expression evaluation when the target
350 uses different floating-point formats than the host. At least version
351 3.1 of GNU MPFR is required.
353 * GDB now supports access to the guarded-storage-control registers and the
354 software-based guarded-storage broadcast control registers on IBM z14.
356 * On Unix systems, GDB now supports transmitting environment variables
357 that are to be set or unset to GDBserver. These variables will
358 affect the environment to be passed to the remote inferior.
360 To inform GDB of environment variables that are to be transmitted to
361 GDBserver, use the "set environment" command. Only user set
362 environment variables are sent to GDBserver.
364 To inform GDB of environment variables that are to be unset before
365 the remote inferior is started by the GDBserver, use the "unset
366 environment" command.
368 * Completion improvements
370 ** GDB can now complete function parameters in linespecs and
371 explicit locations without quoting. When setting breakpoints,
372 quoting around functions names to help with TAB-completion is
373 generally no longer necessary. For example, this now completes
376 (gdb) b function(in[TAB]
377 (gdb) b function(int)
379 Related, GDB is no longer confused with completing functions in
380 C++ anonymous namespaces:
383 (gdb) b (anonymous namespace)::[TAB][TAB]
384 (anonymous namespace)::a_function()
385 (anonymous namespace)::b_function()
387 ** GDB now has much improved linespec and explicit locations TAB
388 completion support, that better understands what you're
389 completing and offers better suggestions. For example, GDB no
390 longer offers data symbols as possible completions when you're
391 setting a breakpoint.
393 ** GDB now TAB-completes label symbol names.
395 ** The "complete" command now mimics TAB completion accurately.
397 * New command line options (gcore)
400 Dump all memory mappings.
402 * Breakpoints on C++ functions are now set on all scopes by default
404 By default, breakpoints on functions/methods are now interpreted as
405 specifying all functions with the given name ignoring missing
406 leading scopes (namespaces and classes).
408 For example, assuming a C++ program with symbols named:
413 both commands "break func()" and "break B::func()" set a breakpoint
416 You can use the new flag "-qualified" to override this. This makes
417 GDB interpret the specified function name as a complete
418 fully-qualified name instead. For example, using the same C++
419 program, the "break -q B::func" command sets a breakpoint on
420 "B::func", only. A parameter has been added to the Python
421 gdb.Breakpoint constructor to achieve the same result when creating
422 a breakpoint from Python.
424 * Breakpoints on functions marked with C++ ABI tags
426 GDB can now set breakpoints on functions marked with C++ ABI tags
427 (e.g., [abi:cxx11]). See here for a description of ABI tags:
428 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
430 Functions with a C++11 abi tag are demangled/displayed like this:
432 function[abi:cxx11](int)
435 You can now set a breakpoint on such functions simply as if they had
438 (gdb) b function(int)
440 Or if you need to disambiguate between tags, like:
442 (gdb) b function[abi:other_tag](int)
444 Tab completion was adjusted accordingly as well.
448 ** New events gdb.new_inferior, gdb.inferior_deleted, and
449 gdb.new_thread are emitted. See the manual for further
450 description of these.
452 ** A new function, "gdb.rbreak" has been added to the Python API.
453 This function allows the setting of a large number of breakpoints
454 via a regex pattern in Python. See the manual for further details.
456 ** Python breakpoints can now accept explicit locations. See the
457 manual for a further description of this feature.
460 * New features in the GDB remote stub, GDBserver
462 ** GDBserver is now able to start inferior processes with a
463 specified initial working directory.
465 The user can set the desired working directory to be used from
466 GDB using the new "set cwd" command.
468 ** New "--selftest" command line option runs some GDBserver self
469 tests. These self tests are disabled in releases.
471 ** On Unix systems, GDBserver now does globbing expansion and variable
472 substitution in inferior command line arguments.
474 This is done by starting inferiors using a shell, like GDB does.
475 See "set startup-with-shell" in the user manual for how to disable
476 this from GDB when using "target extended-remote". When using
477 "target remote", you can disable the startup with shell by using the
478 new "--no-startup-with-shell" GDBserver command line option.
480 ** On Unix systems, GDBserver now supports receiving environment
481 variables that are to be set or unset from GDB. These variables
482 will affect the environment to be passed to the inferior.
484 * When catching an Ada exception raised with a message, GDB now prints
485 the message in the catchpoint hit notification. In GDB/MI mode, that
486 information is provided as an extra field named "exception-message"
487 in the *stopped notification.
489 * Trait objects can now be inspected When debugging Rust code. This
490 requires compiler support which will appear in Rust 1.24.
494 QEnvironmentHexEncoded
495 Inform GDBserver of an environment variable that is to be passed to
496 the inferior when starting it.
499 Inform GDBserver of an environment variable that is to be unset
500 before starting the remote inferior.
503 Inform GDBserver that the environment should be reset (i.e.,
504 user-set environment variables should be unset).
507 Indicates whether the inferior must be started with a shell or not.
510 Tell GDBserver that the inferior to be started should use a specific
513 * The "maintenance print c-tdesc" command now takes an optional
514 argument which is the file name of XML target description.
516 * The "maintenance selftest" command now takes an optional argument to
517 filter the tests to be run.
519 * The "enable", and "disable" commands now accept a range of
520 breakpoint locations, e.g. "enable 1.3-5".
525 Set and show the current working directory for the inferior.
528 Set and show compilation command used for compiling and injecting code
529 with the 'compile' commands.
531 set debug separate-debug-file
532 show debug separate-debug-file
533 Control the display of debug output about separate debug file search.
535 set dump-excluded-mappings
536 show dump-excluded-mappings
537 Control whether mappings marked with the VM_DONTDUMP flag should be
538 dumped when generating a core file.
541 List the registered selftests.
544 Start the debugged program stopping at the first instruction.
547 Control display of debugging messages related to OpenRISC targets.
549 set|show print type nested-type-limit
550 Set and show the limit of nesting level for nested types that the
551 type printer will show.
553 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
556 * Safer/improved support for debugging with no debug info
558 GDB no longer assumes functions with no debug information return
561 This means that GDB now refuses to call such functions unless you
562 tell it the function's type, by either casting the call to the
563 declared return type, or by casting the function to a function
564 pointer of the right type, and calling that:
566 (gdb) p getenv ("PATH")
567 'getenv' has unknown return type; cast the call to its declared return type
568 (gdb) p (char *) getenv ("PATH")
569 $1 = 0x7fffffffe "/usr/local/bin:/"...
570 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
571 $2 = 0x7fffffffe "/usr/local/bin:/"...
573 Similarly, GDB no longer assumes that global variables with no debug
574 info have type 'int', and refuses to print the variable's value
575 unless you tell it the variable's type:
578 'var' has unknown type; cast it to its declared type
582 * New native configurations
584 FreeBSD/aarch64 aarch64*-*-freebsd*
585 FreeBSD/arm arm*-*-freebsd*
589 FreeBSD/aarch64 aarch64*-*-freebsd*
590 FreeBSD/arm arm*-*-freebsd*
591 OpenRISC ELF or1k*-*-elf
593 * Removed targets and native configurations
595 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
597 *** Changes in GDB 8.0
599 * GDB now supports access to the PKU register on GNU/Linux. The register is
600 added by the Memory Protection Keys for Userspace feature which will be
601 available in future Intel CPUs.
603 * GDB now supports C++11 rvalue references.
607 ** New functions to start, stop and access a running btrace recording.
608 ** Rvalue references are now supported in gdb.Type.
610 * GDB now supports recording and replaying rdrand and rdseed Intel 64
613 * Building GDB and GDBserver now requires a C++11 compiler.
615 For example, GCC 4.8 or later.
617 It is no longer possible to build GDB or GDBserver with a C
618 compiler. The --disable-build-with-cxx configure option has been
621 * Building GDB and GDBserver now requires GNU make >= 3.81.
623 It is no longer supported to build GDB or GDBserver with another
624 implementation of the make program or an earlier version of GNU make.
626 * Native debugging on MS-Windows supports command-line redirection
628 Command-line arguments used for starting programs on MS-Windows can
629 now include redirection symbols supported by native Windows shells,
630 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
631 as "run", "start", and "set args", as well as the corresponding MI
634 * Support for thread names on MS-Windows.
636 GDB now catches and handles the special exception that programs
637 running on MS-Windows use to assign names to threads in the
640 * Support for Java programs compiled with gcj has been removed.
642 * User commands now accept an unlimited number of arguments.
643 Previously, only up to 10 was accepted.
645 * The "eval" command now expands user-defined command arguments.
647 This makes it easier to process a variable number of arguments:
652 eval "print $arg%d", $i
657 * Target descriptions can now describe registers for sparc32 and sparc64.
659 * GDB now supports DWARF version 5 (debug information format).
660 Its .debug_names index is not yet supported.
662 * New native configurations
664 FreeBSD/mips mips*-*-freebsd
668 Synopsys ARC arc*-*-elf32
669 FreeBSD/mips mips*-*-freebsd
671 * Removed targets and native configurations
673 Alpha running FreeBSD alpha*-*-freebsd*
674 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
679 Erases all the flash memory regions reported by the target.
681 maint print arc arc-instruction address
682 Print internal disassembler information about instruction at a given address.
686 set disassembler-options
687 show disassembler-options
688 Controls the passing of target specific information to the disassembler.
689 If it is necessary to specify more than one disassembler option then
690 multiple options can be placed together into a comma separated list.
691 The default value is the empty string. Currently, the only supported
692 targets are ARM, PowerPC and S/390.
697 Erases all the flash memory regions reported by the target. This is
698 equivalent to the CLI command flash-erase.
700 -file-list-shared-libraries
701 List the shared libraries in the program. This is
702 equivalent to the CLI command "info shared".
705 Catchpoints stopping the program when Ada exceptions are
706 handled. This is equivalent to the CLI command "catch handlers".
708 *** Changes in GDB 7.12
710 * GDB and GDBserver now build with a C++ compiler by default.
712 The --enable-build-with-cxx configure option is now enabled by
713 default. One must now explicitly configure with
714 --disable-build-with-cxx in order to build with a C compiler. This
715 option will be removed in a future release.
717 * GDBserver now supports recording btrace without maintaining an active
720 * GDB now supports a negative repeat count in the 'x' command to examine
721 memory backward from the given address. For example:
724 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
725 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
726 (gdb) x/-5i 0x0000000000400580
727 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
728 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
729 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
730 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
731 0x40057b <main(int, char**)+25>:
732 callq 0x400536 <Func1(int, char const*)>
734 * Fortran: Support structures with fields of dynamic types and
735 arrays of dynamic types.
737 * The symbol dumping maintenance commands have new syntax.
738 maint print symbols [-pc address] [--] [filename]
739 maint print symbols [-objfile objfile] [-source source] [--] [filename]
740 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
741 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
742 maint print msymbols [-objfile objfile] [--] [filename]
744 * GDB now supports multibit bitfields and enums in target register
747 * New Python-based convenience function $_as_string(val), which returns
748 the textual representation of a value. This function is especially
749 useful to obtain the text label of an enum value.
751 * Intel MPX bound violation handling.
753 Segmentation faults caused by a Intel MPX boundary violation
754 now display the kind of violation (upper or lower), the memory
755 address accessed and the memory bounds, along with the usual
756 signal received and code location.
760 Program received signal SIGSEGV, Segmentation fault
761 Upper bound violation while accessing address 0x7fffffffc3b3
762 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
763 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
765 * Rust language support.
766 GDB now supports debugging programs written in the Rust programming
767 language. See https://www.rust-lang.org/ for more information about
770 * Support for running interpreters on specified input/output devices
772 GDB now supports a new mechanism that allows frontends to provide
773 fully featured GDB console views, as a better alternative to
774 building such views on top of the "-interpreter-exec console"
775 command. See the new "new-ui" command below. With that command,
776 frontends can now start GDB in the traditional command-line mode
777 running in an embedded terminal emulator widget, and create a
778 separate MI interpreter running on a specified i/o device. In this
779 way, GDB handles line editing, history, tab completion, etc. in the
780 console all by itself, and the GUI uses the separate MI interpreter
781 for its own control and synchronization, invisible to the command
784 * The "catch syscall" command catches groups of related syscalls.
786 The "catch syscall" command now supports catching a group of related
787 syscalls using the 'group:' or 'g:' prefix.
792 skip -gfile file-glob-pattern
793 skip -function function
794 skip -rfunction regular-expression
795 A generalized form of the skip command, with new support for
796 glob-style file names and regular expressions for function names.
797 Additionally, a file spec and a function spec may now be combined.
799 maint info line-table REGEXP
800 Display the contents of GDB's internal line table data struture.
803 Run any GDB unit tests that were compiled in.
806 Start a new user interface instance running INTERP as interpreter,
807 using the TTY file for input/output.
811 ** gdb.Breakpoint objects have a new attribute "pending", which
812 indicates whether the breakpoint is pending.
813 ** Three new breakpoint-related events have been added:
814 gdb.breakpoint_created, gdb.breakpoint_modified, and
815 gdb.breakpoint_deleted.
818 Signal ("set") the given MS-Windows event object. This is used in
819 conjunction with the Windows JIT debugging (AeDebug) support, where
820 the OS suspends a crashing process until a debugger can attach to
821 it. Resuming the crashing process, in order to debug it, is done by
824 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
825 was added in GDBserver, including JIT compiling fast tracepoint's
826 conditional expression bytecode into native code.
828 * Support for various remote target protocols and ROM monitors has
831 target m32rsdi Remote M32R debugging over SDI
832 target mips MIPS remote debugging protocol
833 target pmon PMON ROM monitor
834 target ddb NEC's DDB variant of PMON for Vr4300
835 target rockhopper NEC RockHopper variant of PMON
836 target lsi LSI variant of PMO
838 * Support for tracepoints and fast tracepoints on powerpc-linux,
839 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
840 including JIT compiling fast tracepoint's conditional expression
841 bytecode into native code.
843 * MI async record =record-started now includes the method and format used for
844 recording. For example:
846 =record-started,thread-group="i1",method="btrace",format="bts"
848 * MI async record =thread-selected now includes the frame field. For example:
850 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
854 Andes NDS32 nds32*-*-elf
856 *** Changes in GDB 7.11
858 * GDB now supports debugging kernel-based threads on FreeBSD.
860 * Per-inferior thread numbers
862 Thread numbers are now per inferior instead of global. If you're
863 debugging multiple inferiors, GDB displays thread IDs using a
864 qualified INF_NUM.THR_NUM form. For example:
868 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
869 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
870 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
871 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
873 As consequence, thread numbers as visible in the $_thread
874 convenience variable and in Python's InferiorThread.num attribute
875 are no longer unique between inferiors.
877 GDB now maintains a second thread ID per thread, referred to as the
878 global thread ID, which is the new equivalent of thread numbers in
879 previous releases. See also $_gthread below.
881 For backwards compatibility, MI's thread IDs always refer to global
884 * Commands that accept thread IDs now accept the qualified
885 INF_NUM.THR_NUM form as well. For example:
888 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
891 * In commands that accept a list of thread IDs, you can now refer to
892 all threads of an inferior using a star wildcard. GDB accepts
893 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
894 refer to all threads of the current inferior. For example, "info
897 * You can use "info threads -gid" to display the global thread ID of
900 * The new convenience variable $_gthread holds the global number of
903 * The new convenience variable $_inferior holds the number of the
906 * GDB now displays the ID and name of the thread that hit a breakpoint
907 or received a signal, if your program is multi-threaded. For
910 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
911 Thread 1 "main" received signal SIGINT, Interrupt.
913 * Record btrace now supports non-stop mode.
915 * Support for tracepoints on aarch64-linux was added in GDBserver.
917 * The 'record instruction-history' command now indicates speculative execution
918 when using the Intel Processor Trace recording format.
920 * GDB now allows users to specify explicit locations, bypassing
921 the linespec parser. This feature is also available to GDB/MI
924 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
925 GDB now is able to debug both AArch64 applications and ARM applications
928 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
929 including JIT compiling fast tracepoint's conditional expression bytecode
932 * GDB now supports displaced stepping on AArch64 GNU/Linux.
934 * "info threads", "info inferiors", "info display", "info checkpoints"
935 and "maint info program-spaces" now list the corresponding items in
936 ascending ID order, for consistency with all other "info" commands.
938 * In Ada, the overloads selection menu has been enhanced to display the
939 parameter types and the return types for the matching overloaded subprograms.
943 maint set target-non-stop (on|off|auto)
944 maint show target-non-stop
945 Control whether GDB targets always operate in non-stop mode even if
946 "set non-stop" is "off". The default is "auto", meaning non-stop
947 mode is enabled if supported by the target.
949 maint set bfd-sharing
950 maint show bfd-sharing
951 Control the reuse of bfd objects.
955 Control display of debugging info regarding bfd caching.
959 Control display of debugging info regarding FreeBSD threads.
961 set remote multiprocess-extensions-packet
962 show remote multiprocess-extensions-packet
963 Set/show the use of the remote protocol multiprocess extensions.
965 set remote thread-events
966 show remote thread-events
967 Set/show the use of thread create/exit events.
969 set ada print-signatures on|off
970 show ada print-signatures"
971 Control whether parameter types and return types are displayed in overloads
972 selection menus. It is activaled (@code{on}) by default.
976 Controls the maximum size of memory, in bytes, that GDB will
977 allocate for value contents. Prevents incorrect programs from
978 causing GDB to allocate overly large buffers. Default is 64k.
980 * The "disassemble" command accepts a new modifier: /s.
981 It prints mixed source+disassembly like /m with two differences:
982 - disassembled instructions are now printed in program order, and
983 - and source for all relevant files is now printed.
984 The "/m" option is now considered deprecated: its "source-centric"
985 output hasn't proved useful in practice.
987 * The "record instruction-history" command accepts a new modifier: /s.
988 It behaves exactly like /m and prints mixed source+disassembly.
990 * The "set scheduler-locking" command supports a new mode "replay".
991 It behaves like "off" in record mode and like "on" in replay mode.
993 * Support for various ROM monitors has been removed:
995 target dbug dBUG ROM monitor for Motorola ColdFire
996 target picobug Motorola picobug monitor
997 target dink32 DINK32 ROM monitor for PowerPC
998 target m32r Renesas M32R/D ROM monitor
999 target mon2000 mon2000 ROM monitor
1000 target ppcbug PPCBUG ROM monitor for PowerPC
1002 * Support for reading/writing memory and extracting values on architectures
1003 whose memory is addressable in units of any integral multiple of 8 bits.
1006 Allows to break when an Ada exception is handled.
1008 * New remote packets
1011 Indicates that an exec system call was executed.
1013 exec-events feature in qSupported
1014 The qSupported packet allows GDB to request support for exec
1015 events using the new 'gdbfeature' exec-event, and the qSupported
1016 response can contain the corresponding 'stubfeature'. Set and
1017 show commands can be used to display whether these features are enabled.
1020 Equivalent to interrupting with the ^C character, but works in
1023 thread created stop reason (T05 create:...)
1024 Indicates that the thread was just created and is stopped at entry.
1026 thread exit stop reply (w exitcode;tid)
1027 Indicates that the thread has terminated.
1030 Enables/disables thread create and exit event reporting. For
1031 example, this is used in non-stop mode when GDB stops a set of
1032 threads and synchronously waits for the their corresponding stop
1033 replies. Without exit events, if one of the threads exits, GDB
1034 would hang forever not knowing that it should no longer expect a
1035 stop for that same thread.
1038 Indicates that there are no resumed threads left in the target (all
1039 threads are stopped). The remote stub reports support for this stop
1040 reply to GDB's qSupported query.
1043 Enables/disables catching syscalls from the inferior process.
1044 The remote stub reports support for this packet to GDB's qSupported query.
1046 syscall_entry stop reason
1047 Indicates that a syscall was just called.
1049 syscall_return stop reason
1050 Indicates that a syscall just returned.
1052 * Extended-remote exec events
1054 ** GDB now has support for exec events on extended-remote Linux targets.
1055 For such targets with Linux kernels 2.5.46 and later, this enables
1056 follow-exec-mode and exec catchpoints.
1058 set remote exec-event-feature-packet
1059 show remote exec-event-feature-packet
1060 Set/show the use of the remote exec event feature.
1062 * Thread names in remote protocol
1064 The reply to qXfer:threads:read may now include a name attribute for each
1067 * Target remote mode fork and exec events
1069 ** GDB now has support for fork and exec events on target remote mode
1070 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1071 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1072 fork and exec catchpoints.
1074 * Remote syscall events
1076 ** GDB now has support for catch syscall on remote Linux targets,
1077 currently enabled on x86/x86_64 architectures.
1079 set remote catch-syscall-packet
1080 show remote catch-syscall-packet
1081 Set/show the use of the remote catch syscall feature.
1085 ** The -var-set-format command now accepts the zero-hexadecimal
1086 format. It outputs data in hexadecimal format with zero-padding on the
1091 ** gdb.InferiorThread objects have a new attribute "global_num",
1092 which refers to the thread's global thread ID. The existing
1093 "num" attribute now refers to the thread's per-inferior number.
1094 See "Per-inferior thread numbers" above.
1095 ** gdb.InferiorThread objects have a new attribute "inferior", which
1096 is the Inferior object the thread belongs to.
1098 *** Changes in GDB 7.10
1100 * Support for process record-replay and reverse debugging on aarch64*-linux*
1101 targets has been added. GDB now supports recording of A64 instruction set
1102 including advance SIMD instructions.
1104 * Support for Sun's version of the "stabs" debug file format has been removed.
1106 * GDB now honors the content of the file /proc/PID/coredump_filter
1107 (PID is the process ID) on GNU/Linux systems. This file can be used
1108 to specify the types of memory mappings that will be included in a
1109 corefile. For more information, please refer to the manual page of
1110 "core(5)". GDB also has a new command: "set use-coredump-filter
1111 on|off". It allows to set whether GDB will read the content of the
1112 /proc/PID/coredump_filter file when generating a corefile.
1114 * The "info os" command on GNU/Linux can now display information on
1116 "info os cpus" Listing of all cpus/cores on the system
1118 * GDB has two new commands: "set serial parity odd|even|none" and
1119 "show serial parity". These allows to set or show parity for the
1122 * The "info source" command now displays the producer string if it was
1123 present in the debug info. This typically includes the compiler version
1124 and may include things like its command line arguments.
1126 * The "info dll", an alias of the "info sharedlibrary" command,
1127 is now available on all platforms.
1129 * Directory names supplied to the "set sysroot" commands may be
1130 prefixed with "target:" to tell GDB to access shared libraries from
1131 the target system, be it local or remote. This replaces the prefix
1132 "remote:". The default sysroot has been changed from "" to
1133 "target:". "remote:" is automatically converted to "target:" for
1134 backward compatibility.
1136 * The system root specified by "set sysroot" will be prepended to the
1137 filename of the main executable (if reported to GDB as absolute by
1138 the operating system) when starting processes remotely, and when
1139 attaching to already-running local or remote processes.
1141 * GDB now supports automatic location and retrieval of executable
1142 files from remote targets. Remote debugging can now be initiated
1143 using only a "target remote" or "target extended-remote" command
1144 (no "set sysroot" or "file" commands are required). See "New remote
1147 * The "dump" command now supports verilog hex format.
1149 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1151 * On GNU/Linux, GDB and gdbserver are now able to access executable
1152 and shared library files without a "set sysroot" command when
1153 attaching to processes running in different mount namespaces from
1154 the debugger. This makes it possible to attach to processes in
1155 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1156 See "New remote packets" below.
1158 * The "tui reg" command now provides completion for all of the
1159 available register groups, including target specific groups.
1161 * The HISTSIZE environment variable is no longer read when determining
1162 the size of GDB's command history. GDB now instead reads the dedicated
1163 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1164 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1169 ** Memory ports can now be unbuffered.
1173 ** gdb.Objfile objects have a new attribute "username",
1174 which is the name of the objfile as specified by the user,
1175 without, for example, resolving symlinks.
1176 ** You can now write frame unwinders in Python.
1177 ** gdb.Type objects have a new method "optimized_out",
1178 returning optimized out gdb.Value instance of this type.
1179 ** gdb.Value objects have new methods "reference_value" and
1180 "const_value" which return a reference to the value and a
1181 "const" version of the value respectively.
1185 maint print symbol-cache
1186 Print the contents of the symbol cache.
1188 maint print symbol-cache-statistics
1189 Print statistics of symbol cache usage.
1191 maint flush-symbol-cache
1192 Flush the contents of the symbol cache.
1196 Start branch trace recording using Branch Trace Store (BTS) format.
1199 Evaluate expression by using the compiler and print result.
1203 Explicit commands for enabling and disabling tui mode.
1206 set mpx bound on i386 and amd64
1207 Support for bound table investigation on Intel MPX enabled applications.
1211 Start branch trace recording using Intel Processor Trace format.
1214 Print information about branch tracing internals.
1216 maint btrace packet-history
1217 Print the raw branch tracing data.
1219 maint btrace clear-packet-history
1220 Discard the stored raw branch tracing data.
1223 Discard all branch tracing data. It will be fetched and processed
1224 anew by the next "record" command.
1229 Renamed from "set debug dwarf2-die".
1230 show debug dwarf-die
1231 Renamed from "show debug dwarf2-die".
1233 set debug dwarf-read
1234 Renamed from "set debug dwarf2-read".
1235 show debug dwarf-read
1236 Renamed from "show debug dwarf2-read".
1238 maint set dwarf always-disassemble
1239 Renamed from "maint set dwarf2 always-disassemble".
1240 maint show dwarf always-disassemble
1241 Renamed from "maint show dwarf2 always-disassemble".
1243 maint set dwarf max-cache-age
1244 Renamed from "maint set dwarf2 max-cache-age".
1245 maint show dwarf max-cache-age
1246 Renamed from "maint show dwarf2 max-cache-age".
1248 set debug dwarf-line
1249 show debug dwarf-line
1250 Control display of debugging info regarding DWARF line processing.
1253 show max-completions
1254 Set the maximum number of candidates to be considered during
1255 completion. The default value is 200. This limit allows GDB
1256 to avoid generating large completion lists, the computation of
1257 which can cause the debugger to become temporarily unresponsive.
1259 set history remove-duplicates
1260 show history remove-duplicates
1261 Control the removal of duplicate history entries.
1263 maint set symbol-cache-size
1264 maint show symbol-cache-size
1265 Control the size of the symbol cache.
1267 set|show record btrace bts buffer-size
1268 Set and show the size of the ring buffer used for branch tracing in
1270 The obtained size may differ from the requested size. Use "info
1271 record" to see the obtained buffer size.
1273 set debug linux-namespaces
1274 show debug linux-namespaces
1275 Control display of debugging info regarding Linux namespaces.
1277 set|show record btrace pt buffer-size
1278 Set and show the size of the ring buffer used for branch tracing in
1279 Intel Processor Trace format.
1280 The obtained size may differ from the requested size. Use "info
1281 record" to see the obtained buffer size.
1283 maint set|show btrace pt skip-pad
1284 Set and show whether PAD packets are skipped when computing the
1287 * The command 'thread apply all' can now support new option '-ascending'
1288 to call its specified command for all threads in ascending order.
1290 * Python/Guile scripting
1292 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1293 special section named `.debug_gdb_scripts'.
1295 * New remote packets
1297 qXfer:btrace-conf:read
1298 Return the branch trace configuration for the current thread.
1300 Qbtrace-conf:bts:size
1301 Set the requested ring buffer size for branch tracing in BTS format.
1304 Enable Intel Procesor Trace-based branch tracing for the current
1305 process. The remote stub reports support for this packet to GDB's
1308 Qbtrace-conf:pt:size
1309 Set the requested ring buffer size for branch tracing in Intel Processor
1313 Indicates a memory breakpoint instruction was executed, irrespective
1314 of whether it was GDB that planted the breakpoint or the breakpoint
1315 is hardcoded in the program. This is required for correct non-stop
1319 Indicates the target stopped for a hardware breakpoint. This is
1320 required for correct non-stop mode operation.
1323 Return information about files on the remote system.
1325 qXfer:exec-file:read
1326 Return the full absolute name of the file that was executed to
1327 create a process running on the remote system.
1330 Select the filesystem on which vFile: operations with filename
1331 arguments will operate. This is required for GDB to be able to
1332 access files on remote targets where the remote stub does not
1333 share a common filesystem with the inferior(s).
1336 Indicates that a fork system call was executed.
1339 Indicates that a vfork system call was executed.
1341 vforkdone stop reason
1342 Indicates that a vfork child of the specified process has executed
1343 an exec or exit, allowing the vfork parent to resume execution.
1345 fork-events and vfork-events features in qSupported
1346 The qSupported packet allows GDB to request support for fork and
1347 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1348 and the qSupported response can contain the corresponding
1349 'stubfeatures'. Set and show commands can be used to display
1350 whether these features are enabled.
1352 * Extended-remote fork events
1354 ** GDB now has support for fork events on extended-remote Linux
1355 targets. For targets with Linux kernels 2.5.60 and later, this
1356 enables follow-fork-mode and detach-on-fork for both fork and
1357 vfork, as well as fork and vfork catchpoints.
1359 * The info record command now shows the recording format and the
1360 branch tracing configuration for the current thread when using
1361 the btrace record target.
1362 For the BTS format, it shows the ring buffer size.
1364 * GDB now has support for DTrace USDT (Userland Static Defined
1365 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1367 * GDB now supports access to vector registers on S/390 GNU/Linux
1370 * Removed command line options
1372 -xdb HP-UX XDB compatibility mode.
1374 * Removed targets and native configurations
1376 HP/PA running HP-UX hppa*-*-hpux*
1377 Itanium running HP-UX ia64-*-hpux*
1379 * New configure options
1382 This configure option allows the user to build GDB with support for
1383 Intel Processor Trace (default: auto). This requires libipt.
1385 --with-libipt-prefix=PATH
1386 Specify the path to the version of libipt that GDB should use.
1387 $PATH/include should contain the intel-pt.h header and
1388 $PATH/lib should contain the libipt.so library.
1390 *** Changes in GDB 7.9.1
1394 ** Xmethods can now specify a result type.
1396 *** Changes in GDB 7.9
1398 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1402 ** You can now access frame registers from Python scripts.
1403 ** New attribute 'producer' for gdb.Symtab objects.
1404 ** gdb.Objfile objects have a new attribute "progspace",
1405 which is the gdb.Progspace object of the containing program space.
1406 ** gdb.Objfile objects have a new attribute "owner".
1407 ** gdb.Objfile objects have a new attribute "build_id",
1408 which is the build ID generated when the file was built.
1409 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1410 ** A new event "gdb.clear_objfiles" has been added, triggered when
1411 selecting a new file to debug.
1412 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1413 ** New function gdb.lookup_objfile.
1415 New events which are triggered when GDB modifies the state of the
1418 ** gdb.events.inferior_call_pre: Function call is about to be made.
1419 ** gdb.events.inferior_call_post: Function call has just been made.
1420 ** gdb.events.memory_changed: A memory location has been altered.
1421 ** gdb.events.register_changed: A register has been altered.
1423 * New Python-based convenience functions:
1425 ** $_caller_is(name [, number_of_frames])
1426 ** $_caller_matches(regexp [, number_of_frames])
1427 ** $_any_caller_is(name [, number_of_frames])
1428 ** $_any_caller_matches(regexp [, number_of_frames])
1430 * GDB now supports the compilation and injection of source code into
1431 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1432 to compile the source code to object code, and if successful, inject
1433 and execute that code within the current context of the inferior.
1434 Currently the C language is supported. The commands used to
1435 interface with this new feature are:
1437 compile code [-raw|-r] [--] [source code]
1438 compile file [-raw|-r] filename
1442 demangle [-l language] [--] name
1443 Demangle "name" in the specified language, or the current language
1444 if elided. This command is renamed from the "maint demangle" command.
1445 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1446 as "maint demangler-warning".
1448 queue-signal signal-name-or-number
1449 Queue a signal to be delivered to the thread when it is resumed.
1451 add-auto-load-scripts-directory directory
1452 Add entries to the list of directories from which to load auto-loaded
1455 maint print user-registers
1456 List all currently available "user" registers.
1458 compile code [-r|-raw] [--] [source code]
1459 Compile, inject, and execute in the inferior the executable object
1460 code produced by compiling the provided source code.
1462 compile file [-r|-raw] filename
1463 Compile and inject into the inferior the executable object code
1464 produced by compiling the source code stored in the filename
1467 * On resume, GDB now always passes the signal the program had stopped
1468 for to the thread the signal was sent to, even if the user changed
1469 threads before resuming. Previously GDB would often (but not
1470 always) deliver the signal to the thread that happens to be current
1473 * Conversely, the "signal" command now consistently delivers the
1474 requested signal to the current thread. GDB now asks for
1475 confirmation if the program had stopped for a signal and the user
1476 switched threads meanwhile.
1478 * "breakpoint always-inserted" modes "off" and "auto" merged.
1480 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1481 won't remove breakpoints from the target until all threads stop,
1482 even in non-stop mode. The "auto" mode has been removed, and "off"
1483 is now the default mode.
1487 set debug symbol-lookup
1488 show debug symbol-lookup
1489 Control display of debugging info regarding symbol lookup.
1493 ** The -list-thread-groups command outputs an exit-code field for
1494 inferiors that have exited.
1498 MIPS SDE mips*-sde*-elf*
1502 Support for these obsolete configurations has been removed.
1504 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1505 SGI Irix-5.x mips-*-irix5*
1506 SGI Irix-6.x mips-*-irix6*
1507 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1508 VAX running Ultrix vax-*-ultrix*
1510 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1511 and "assf"), have been removed. Use the "sharedlibrary" command, or
1512 its alias "share", instead.
1514 *** Changes in GDB 7.8
1516 * New command line options
1519 This is an alias for the --data-directory option.
1521 * GDB supports printing and modifying of variable length automatic arrays
1522 as specified in ISO C99.
1524 * The ARM simulator now supports instruction level tracing
1525 with or without disassembly.
1529 GDB now has support for scripting using Guile. Whether this is
1530 available is determined at configure time.
1531 Guile version 2.0 or greater is required.
1532 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1534 * New commands (for set/show, see "New options" below)
1538 Invoke CODE by passing it to the Guile interpreter.
1542 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1544 info auto-load guile-scripts [regexp]
1545 Print the list of automatically loaded Guile scripts.
1547 * The source command is now capable of sourcing Guile scripts.
1548 This feature is dependent on the debugger being built with Guile support.
1552 set print symbol-loading (off|brief|full)
1553 show print symbol-loading
1554 Control whether to print informational messages when loading symbol
1555 information for a file. The default is "full", but when debugging
1556 programs with large numbers of shared libraries the amount of output
1557 becomes less useful.
1559 set guile print-stack (none|message|full)
1560 show guile print-stack
1561 Show a stack trace when an error is encountered in a Guile script.
1563 set auto-load guile-scripts (on|off)
1564 show auto-load guile-scripts
1565 Control auto-loading of Guile script files.
1567 maint ada set ignore-descriptive-types (on|off)
1568 maint ada show ignore-descriptive-types
1569 Control whether the debugger should ignore descriptive types in Ada
1570 programs. The default is not to ignore the descriptive types. See
1571 the user manual for more details on descriptive types and the intended
1572 usage of this option.
1574 set auto-connect-native-target
1576 Control whether GDB is allowed to automatically connect to the
1577 native target for the run, attach, etc. commands when not connected
1578 to any target yet. See also "target native" below.
1580 set record btrace replay-memory-access (read-only|read-write)
1581 show record btrace replay-memory-access
1582 Control what memory accesses are allowed during replay.
1584 maint set target-async (on|off)
1585 maint show target-async
1586 This controls whether GDB targets operate in synchronous or
1587 asynchronous mode. Normally the default is asynchronous, if it is
1588 available; but this can be changed to more easily debug problems
1589 occurring only in synchronous mode.
1591 set mi-async (on|off)
1593 Control whether MI asynchronous mode is preferred. This supersedes
1594 "set target-async" of previous GDB versions.
1596 * "set target-async" is deprecated as a CLI option and is now an alias
1597 for "set mi-async" (only puts MI into async mode).
1599 * Background execution commands (e.g., "c&", "s&", etc.) are now
1600 possible ``out of the box'' if the target supports them. Previously
1601 the user would need to explicitly enable the possibility with the
1602 "set target-async on" command.
1604 * New features in the GDB remote stub, GDBserver
1606 ** New option --debug-format=option1[,option2,...] allows one to add
1607 additional text to each output. At present only timestamps
1608 are supported: --debug-format=timestamps.
1609 Timestamps can also be turned on with the
1610 "monitor set debug-format timestamps" command from GDB.
1612 * The 'record instruction-history' command now starts counting instructions
1613 at one. This also affects the instruction ranges reported by the
1614 'record function-call-history' command when given the /i modifier.
1616 * The command 'record function-call-history' supports a new modifier '/c' to
1617 indent the function names based on their call stack depth.
1618 The fields for the '/i' and '/l' modifier have been reordered.
1619 The source line range is now prefixed with 'at'.
1620 The instruction range is now prefixed with 'inst'.
1621 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1622 "record instruction-history" and "list" commands.
1624 * The ranges given as arguments to the 'record function-call-history' and
1625 'record instruction-history' commands are now inclusive.
1627 * The btrace record target now supports the 'record goto' command.
1628 For locations inside the execution trace, the back trace is computed
1629 based on the information stored in the execution trace.
1631 * The btrace record target supports limited reverse execution and replay.
1632 The target does not record data and therefore does not allow reading
1633 memory or registers.
1635 * The "catch syscall" command now works on s390*-linux* targets.
1637 * The "compare-sections" command is no longer specific to target
1638 remote. It now works with all targets.
1640 * All native targets are now consistently called "native".
1641 Consequently, the "target child", "target GNU", "target djgpp",
1642 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1643 commands have been replaced with "target native". The QNX/NTO port
1644 leaves the "procfs" target in place and adds a "native" target for
1645 consistency with other ports. The impact on users should be minimal
1646 as these commands previously either throwed an error, or were
1647 no-ops. The target's name is visible in the output of the following
1648 commands: "help target", "info target", "info files", "maint print
1651 * The "target native" command now connects to the native target. This
1652 can be used to launch native programs even when "set
1653 auto-connect-native-target" is set to off.
1655 * GDB now supports access to Intel MPX registers on GNU/Linux.
1657 * Support for Intel AVX-512 registers on GNU/Linux.
1658 Support displaying and modifying Intel AVX-512 registers
1659 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1661 * New remote packets
1663 qXfer:btrace:read's annex
1664 The qXfer:btrace:read packet supports a new annex 'delta' to read
1665 branch trace incrementally.
1669 ** Valid Python operations on gdb.Value objects representing
1670 structs/classes invoke the corresponding overloaded operators if
1672 ** New `Xmethods' feature in the Python API. Xmethods are
1673 additional methods or replacements for existing methods of a C++
1674 class. This feature is useful for those cases where a method
1675 defined in C++ source code could be inlined or optimized out by
1676 the compiler, making it unavailable to GDB.
1679 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1681 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1682 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1683 its alias "share", instead.
1685 * The commands "set remotebaud" and "show remotebaud" are no longer
1686 supported. Use "set serial baud" and "show serial baud" (respectively)
1691 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1692 target-async". The latter is left as a deprecated alias of the
1693 former for backward compatibility. If the target supports it,
1694 CLI background execution commands are now always possible by
1695 default, independently of whether the frontend stated a
1696 preference for asynchronous execution with "-gdb-set mi-async".
1697 Previously "-gdb-set target-async off" affected both MI execution
1698 commands and CLI execution commands.
1700 *** Changes in GDB 7.7
1702 * Improved support for process record-replay and reverse debugging on
1703 arm*-linux* targets. Support for thumb32 and syscall instruction
1704 recording has been added.
1706 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1708 * GDB now supports Fission DWP file format version 2.
1709 http://gcc.gnu.org/wiki/DebugFission
1711 * New convenience function "$_isvoid", to check whether an expression
1712 is void. A void expression is an expression where the type of the
1713 result is "void". For example, some convenience variables may be
1714 "void" when evaluated (e.g., "$_exitcode" before the execution of
1715 the program being debugged; or an undefined convenience variable).
1716 Another example, when calling a function whose return type is
1719 * The "maintenance print objfiles" command now takes an optional regexp.
1721 * The "catch syscall" command now works on arm*-linux* targets.
1723 * GDB now consistently shows "<not saved>" when printing values of
1724 registers the debug info indicates have not been saved in the frame
1725 and there's nowhere to retrieve them from
1726 (callee-saved/call-clobbered registers):
1731 (gdb) info registers rax
1734 Before, the former would print "<optimized out>", and the latter
1735 "*value not available*".
1737 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1742 ** Frame filters and frame decorators have been added.
1743 ** Temporary breakpoints are now supported.
1744 ** Line tables representation has been added.
1745 ** New attribute 'parent_type' for gdb.Field objects.
1746 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1747 ** New attribute 'name' for gdb.Type objects.
1751 Nios II ELF nios2*-*-elf
1752 Nios II GNU/Linux nios2*-*-linux
1753 Texas Instruments MSP430 msp430*-*-elf
1755 * Removed native configurations
1757 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1758 been removed. ELF variants of these configurations are kept supported.
1760 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1761 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1762 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1763 i[34567]86-*-openbsd3.[0-3]
1764 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1765 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1766 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1770 Like "catch throw", but catches a re-thrown exception.
1771 maint check-psymtabs
1772 Renamed from old "maint check-symtabs".
1774 Perform consistency checks on symtabs.
1775 maint expand-symtabs
1776 Expand symtabs matching an optional regexp.
1779 Display the details of GDB configure-time options.
1781 maint set|show per-command
1782 maint set|show per-command space
1783 maint set|show per-command time
1784 maint set|show per-command symtab
1785 Enable display of per-command gdb resource usage.
1787 remove-symbol-file FILENAME
1788 remove-symbol-file -a ADDRESS
1789 Remove a symbol file added via add-symbol-file. The file to remove
1790 can be identified by its filename or by an address that lies within
1791 the boundaries of this symbol file in memory.
1794 info exceptions REGEXP
1795 Display the list of Ada exceptions defined in the program being
1796 debugged. If provided, only the exceptions whose names match REGEXP
1801 set debug symfile off|on
1803 Control display of debugging info regarding reading symbol files and
1804 symbol tables within those files
1806 set print raw frame-arguments
1807 show print raw frame-arguments
1808 Set/show whether to print frame arguments in raw mode,
1809 disregarding any defined pretty-printers.
1811 set remote trace-status-packet
1812 show remote trace-status-packet
1813 Set/show the use of remote protocol qTStatus packet.
1817 Control display of debugging messages related to Nios II targets.
1821 Control whether target-assisted range stepping is enabled.
1823 set startup-with-shell
1824 show startup-with-shell
1825 Specifies whether Unix child processes are started via a shell or
1830 Use the target memory cache for accesses to the code segment. This
1831 improves performance of remote debugging (particularly disassembly).
1833 * You can now use a literal value 'unlimited' for options that
1834 interpret 0 or -1 as meaning "unlimited". E.g., "set
1835 trace-buffer-size unlimited" is now an alias for "set
1836 trace-buffer-size -1" and "set height unlimited" is now an alias for
1839 * The "set debug symtab-create" debugging option of GDB has been changed to
1840 accept a verbosity level. 0 means "off", 1 provides basic debugging
1841 output, and values of 2 or greater provides more verbose output.
1843 * New command-line options
1845 Display the details of GDB configure-time options.
1847 * The command 'tsave' can now support new option '-ctf' to save trace
1848 buffer in Common Trace Format.
1850 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1853 * GDB now implements the the C++ 'typeid' operator.
1855 * The new convenience variable $_exception holds the exception being
1856 thrown or caught at an exception-related catchpoint.
1858 * The exception-related catchpoints, like "catch throw", now accept a
1859 regular expression which can be used to filter exceptions by type.
1861 * The new convenience variable $_exitsignal is automatically set to
1862 the terminating signal number when the program being debugged dies
1863 due to an uncaught signal.
1867 ** All MI commands now accept an optional "--language" option.
1868 Support for this feature can be verified by using the "-list-features"
1869 command, which should contain "language-option".
1871 ** The new command -info-gdb-mi-command allows the user to determine
1872 whether a GDB/MI command is supported or not.
1874 ** The "^error" result record returned when trying to execute an undefined
1875 GDB/MI command now provides a variable named "code" whose content is the
1876 "undefined-command" error code. Support for this feature can be verified
1877 by using the "-list-features" command, which should contain
1878 "undefined-command-error-code".
1880 ** The -trace-save MI command can optionally save trace buffer in Common
1883 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1885 ** The command -data-list-register-values now accepts an optional
1886 "--skip-unavailable" option. When used, only the available registers
1889 ** The new command -trace-frame-collected dumps collected variables,
1890 computed expressions, tvars, memory and registers in a traceframe.
1892 ** The commands -stack-list-locals, -stack-list-arguments and
1893 -stack-list-variables now accept an option "--skip-unavailable".
1894 When used, only the available locals or arguments are displayed.
1896 ** The -exec-run command now accepts an optional "--start" option.
1897 When used, the command follows the same semantics as the "start"
1898 command, stopping the program's execution at the start of its
1899 main subprogram. Support for this feature can be verified using
1900 the "-list-features" command, which should contain
1901 "exec-run-start-option".
1903 ** The new commands -catch-assert and -catch-exceptions insert
1904 catchpoints stopping the program when Ada exceptions are raised.
1906 ** The new command -info-ada-exceptions provides the equivalent of
1907 the new "info exceptions" command.
1909 * New system-wide configuration scripts
1910 A GDB installation now provides scripts suitable for use as system-wide
1911 configuration scripts for the following systems:
1915 * GDB now supports target-assigned range stepping with remote targets.
1916 This improves the performance of stepping source lines by reducing
1917 the number of control packets from/to GDB. See "New remote packets"
1920 * GDB now understands the element 'tvar' in the XML traceframe info.
1921 It has the id of the collected trace state variables.
1923 * On S/390 targets that provide the transactional-execution feature,
1924 the program interruption transaction diagnostic block (TDB) is now
1925 represented as a number of additional "registers" in GDB.
1927 * New remote packets
1931 The vCont packet supports a new 'r' action, that tells the remote
1932 stub to step through an address range itself, without GDB
1933 involvemement at each single-step.
1935 qXfer:libraries-svr4:read's annex
1936 The previously unused annex of the qXfer:libraries-svr4:read packet
1937 is now used to support passing an argument list. The remote stub
1938 reports support for this argument list to GDB's qSupported query.
1939 The defined arguments are "start" and "prev", used to reduce work
1940 necessary for library list updating, resulting in significant
1943 * New features in the GDB remote stub, GDBserver
1945 ** GDBserver now supports target-assisted range stepping. Currently
1946 enabled on x86/x86_64 GNU/Linux targets.
1948 ** GDBserver now adds element 'tvar' in the XML in the reply to
1949 'qXfer:traceframe-info:read'. It has the id of the collected
1950 trace state variables.
1952 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1955 * New 'z' formatter for printing and examining memory, this displays the
1956 value as hexadecimal zero padded on the left to the size of the type.
1958 * GDB can now use Windows x64 unwinding data.
1960 * The "set remotebaud" command has been replaced by "set serial baud".
1961 Similarly, "show remotebaud" has been replaced by "show serial baud".
1962 The "set remotebaud" and "show remotebaud" commands are still available
1963 to provide backward compatibility with older versions of GDB.
1965 *** Changes in GDB 7.6
1967 * Target record has been renamed to record-full.
1968 Record/replay is now enabled with the "record full" command.
1969 This also affects settings that are associated with full record/replay
1970 that have been moved from "set/show record" to "set/show record full":
1972 set|show record full insn-number-max
1973 set|show record full stop-at-limit
1974 set|show record full memory-query
1976 * A new record target "record-btrace" has been added. The new target
1977 uses hardware support to record the control-flow of a process. It
1978 does not support replaying the execution, but it implements the
1979 below new commands for investigating the recorded execution log.
1980 This new recording method can be enabled using:
1984 The "record-btrace" target is only available on Intel Atom processors
1985 and requires a Linux kernel 2.6.32 or later.
1987 * Two new commands have been added for record/replay to give information
1988 about the recorded execution without having to replay the execution.
1989 The commands are only supported by "record btrace".
1991 record instruction-history prints the execution history at
1992 instruction granularity
1994 record function-call-history prints the execution history at
1995 function granularity
1997 * New native configurations
1999 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2000 FreeBSD/powerpc powerpc*-*-freebsd
2001 x86_64/Cygwin x86_64-*-cygwin*
2002 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2006 ARM AArch64 aarch64*-*-elf
2007 ARM AArch64 GNU/Linux aarch64*-*-linux
2008 Lynx 178 PowerPC powerpc-*-lynx*178
2009 x86_64/Cygwin x86_64-*-cygwin*
2010 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2012 * If the configured location of system.gdbinit file (as given by the
2013 --with-system-gdbinit option at configure time) is in the
2014 data-directory (as specified by --with-gdb-datadir at configure
2015 time) or in one of its subdirectories, then GDB will look for the
2016 system-wide init file in the directory specified by the
2017 --data-directory command-line option.
2019 * New command line options:
2021 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2022 other initialization files, unlike -nx which disables all of them.
2024 * Removed command line options
2026 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2029 * The 'ptype' and 'whatis' commands now accept an argument to control
2032 * 'info proc' now works on some core files.
2036 ** Vectors can be created with gdb.Type.vector.
2038 ** Python's atexit.register now works in GDB.
2040 ** Types can be pretty-printed via a Python API.
2042 ** Python 3 is now supported (in addition to Python 2.4 or later)
2044 ** New class gdb.Architecture exposes GDB's internal representation
2045 of architecture in the Python API.
2047 ** New method Frame.architecture returns the gdb.Architecture object
2048 corresponding to the frame's architecture.
2050 * New Python-based convenience functions:
2052 ** $_memeq(buf1, buf2, length)
2053 ** $_streq(str1, str2)
2055 ** $_regex(str, regex)
2057 * The 'cd' command now defaults to using '~' (the home directory) if not
2060 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2061 default for GCC since November 2000.
2063 * The command 'forward-search' can now be abbreviated as 'fo'.
2065 * The command 'info tracepoints' can now display 'installed on target'
2066 or 'not installed on target' for each non-pending location of tracepoint.
2068 * New configure options
2070 --enable-libmcheck/--disable-libmcheck
2071 By default, development versions are built with -lmcheck on hosts
2072 that support it, in order to help track memory corruption issues.
2073 Release versions, on the other hand, are built without -lmcheck
2074 by default. The --enable-libmcheck/--disable-libmcheck configure
2075 options allow the user to override that default.
2076 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2077 This configure option allows the user to build GDB with
2078 libbabeltrace using which GDB can read Common Trace Format data.
2080 * New commands (for set/show, see "New options" below)
2083 Catch signals. This is similar to "handle", but allows commands and
2084 conditions to be attached.
2087 List the BFDs known to GDB.
2089 python-interactive [command]
2091 Start a Python interactive prompt, or evaluate the optional command
2092 and print the result of expressions.
2095 "py" is a new alias for "python".
2097 enable type-printer [name]...
2098 disable type-printer [name]...
2099 Enable or disable type printers.
2103 ** For the Renesas Super-H architecture, the "regs" command has been removed
2104 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2109 set print type methods (on|off)
2110 show print type methods
2111 Control whether method declarations are displayed by "ptype".
2112 The default is to show them.
2114 set print type typedefs (on|off)
2115 show print type typedefs
2116 Control whether typedef definitions are displayed by "ptype".
2117 The default is to show them.
2119 set filename-display basename|relative|absolute
2120 show filename-display
2121 Control the way in which filenames is displayed.
2122 The default is "relative", which preserves previous behavior.
2124 set trace-buffer-size
2125 show trace-buffer-size
2126 Request target to change the size of trace buffer.
2128 set remote trace-buffer-size-packet auto|on|off
2129 show remote trace-buffer-size-packet
2130 Control the use of the remote protocol `QTBuffer:size' packet.
2134 Control display of debugging messages related to ARM AArch64.
2137 set debug coff-pe-read
2138 show debug coff-pe-read
2139 Control display of debugging messages related to reading of COFF/PE
2144 Control display of debugging messages related to Mach-O symbols
2147 set debug notification
2148 show debug notification
2149 Control display of debugging info for async remote notification.
2153 ** Command parameter changes are now notified using new async record
2154 "=cmd-param-changed".
2155 ** Trace frame changes caused by command "tfind" are now notified using
2156 new async record "=traceframe-changed".
2157 ** The creation, deletion and modification of trace state variables
2158 are now notified using new async records "=tsv-created",
2159 "=tsv-deleted" and "=tsv-modified".
2160 ** The start and stop of process record are now notified using new
2161 async record "=record-started" and "=record-stopped".
2162 ** Memory changes are now notified using new async record
2164 ** The data-disassemble command response will include a "fullname" field
2165 containing the absolute file name when source has been requested.
2166 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2167 command, to allow pattern filling of memory areas.
2168 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2169 library load/unload events.
2170 ** The response to breakpoint commands and breakpoint async records
2171 includes an "installed" field containing a boolean state about each
2172 non-pending tracepoint location is whether installed on target or not.
2173 ** Output of the "-trace-status" command includes a "trace-file" field
2174 containing the name of the trace file being examined. This field is
2175 optional, and only present when examining a trace file.
2176 ** The "fullname" field is now always present along with the "file" field,
2177 even if the file cannot be found by GDB.
2179 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2180 You must have the LZMA library available when configuring GDB for this
2181 feature to be enabled. For more information, see:
2182 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2184 * New remote packets
2187 Set the size of trace buffer. The remote stub reports support for this
2188 packet to gdb's qSupported query.
2191 Enable Branch Trace Store (BTS)-based branch tracing for the current
2192 thread. The remote stub reports support for this packet to gdb's
2196 Disable branch tracing for the current thread. The remote stub reports
2197 support for this packet to gdb's qSupported query.
2200 Read the traced branches for the current thread. The remote stub
2201 reports support for this packet to gdb's qSupported query.
2203 *** Changes in GDB 7.5
2205 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2206 for more x32 ABI info.
2208 * GDB now supports access to MIPS DSP registers on Linux targets.
2210 * GDB now supports debugging microMIPS binaries.
2212 * The "info os" command on GNU/Linux can now display information on
2213 several new classes of objects managed by the operating system:
2214 "info os procgroups" lists process groups
2215 "info os files" lists file descriptors
2216 "info os sockets" lists internet-domain sockets
2217 "info os shm" lists shared-memory regions
2218 "info os semaphores" lists semaphores
2219 "info os msg" lists message queues
2220 "info os modules" lists loaded kernel modules
2222 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2223 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2224 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2225 options and inspect the probe arguments using the new $_probe_arg family
2226 of convenience variables. You can obtain more information about SystemTap
2227 in <http://sourceware.org/systemtap/>.
2229 * GDB now supports reversible debugging on ARM, it allows you to
2230 debug basic ARM and THUMB instructions, and provides
2231 record/replay support.
2233 * The option "symbol-reloading" has been deleted as it is no longer used.
2237 ** GDB commands implemented in Python can now be put in command class
2240 ** The "maint set python print-stack on|off" is now deleted.
2242 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2243 apply "flag enum"-style pretty-printing to any enum.
2245 ** gdb.lookup_symbol can now work when there is no current frame.
2247 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2248 the source at which the symbol was defined.
2250 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2251 method 'value'. The former indicates whether the symbol needs a
2252 frame in order to compute its value, and the latter computes the
2255 ** A new method 'referenced_value' on gdb.Value objects which can
2256 dereference pointer as well as C++ reference values.
2258 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2259 which return the global and static blocks (as gdb.Block objects),
2260 of the underlying symbol table, respectively.
2262 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2263 object associated with a PC value.
2265 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2266 of the address range occupied by code for the current source line.
2268 * Go language support.
2269 GDB now supports debugging programs written in the Go programming
2272 * GDBserver now supports stdio connections.
2273 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2275 * The binary "gdbtui" can no longer be built or installed.
2276 Use "gdb -tui" instead.
2278 * GDB will now print "flag" enums specially. A flag enum is one where
2279 all the enumerator values have no bits in common when pairwise
2280 "and"ed. When printing a value whose type is a flag enum, GDB will
2281 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2282 (gdb) print (enum E) 3
2285 * The filename part of a linespec will now match trailing components
2286 of a source file name. For example, "break gcc/expr.c:1000" will
2287 now set a breakpoint in build/gcc/expr.c, but not
2288 build/libcpp/expr.c.
2290 * The "info proc" and "generate-core-file" commands will now also
2291 work on remote targets connected to GDBserver on Linux.
2293 * The command "info catch" has been removed. It has been disabled
2294 since December 2007.
2296 * The "catch exception" and "catch assert" commands now accept
2297 a condition at the end of the command, much like the "break"
2298 command does. For instance:
2300 (gdb) catch exception Constraint_Error if Barrier = True
2302 Previously, it was possible to add a condition to such catchpoints,
2303 but it had to be done as a second step, after the catchpoint had been
2304 created, using the "condition" command.
2306 * The "info static-tracepoint-marker" command will now also work on
2307 native Linux targets with in-process agent.
2309 * GDB can now set breakpoints on inlined functions.
2311 * The .gdb_index section has been updated to include symbols for
2312 inlined functions. GDB will ignore older .gdb_index sections by
2313 default, which could cause symbol files to be loaded more slowly
2314 until their .gdb_index sections can be recreated. The new command
2315 "set use-deprecated-index-sections on" will cause GDB to use any older
2316 .gdb_index sections it finds. This will restore performance, but the
2317 ability to set breakpoints on inlined functions will be lost in symbol
2318 files with older .gdb_index sections.
2320 The .gdb_index section has also been updated to record more information
2321 about each symbol. This speeds up the "info variables", "info functions"
2322 and "info types" commands when used with programs having the .gdb_index
2323 section, as well as speeding up debugging with shared libraries using
2324 the .gdb_index section.
2326 * Ada support for GDB/MI Variable Objects has been added.
2328 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2333 ** New command -info-os is the MI equivalent of "info os".
2335 ** Output logs ("set logging" and related) now include MI output.
2339 ** "set use-deprecated-index-sections on|off"
2340 "show use-deprecated-index-sections on|off"
2341 Controls the use of deprecated .gdb_index sections.
2343 ** "catch load" and "catch unload" can be used to stop when a shared
2344 library is loaded or unloaded, respectively.
2346 ** "enable count" can be used to auto-disable a breakpoint after
2349 ** "info vtbl" can be used to show the virtual method tables for
2350 C++ and Java objects.
2352 ** "explore" and its sub commands "explore value" and "explore type"
2353 can be used to recursively explore values and types of
2354 expressions. These commands are available only if GDB is
2355 configured with '--with-python'.
2357 ** "info auto-load" shows status of all kinds of auto-loaded files,
2358 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2359 sequences of commands files, "info auto-load python-scripts"
2360 shows status of auto-loading Python script files,
2361 "info auto-load local-gdbinit" shows status of loading init file
2362 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2363 status of inferior specific thread debugging shared library loading.
2365 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2366 and "show auto-load-scripts" commands have been deprecated, use their
2367 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2368 and "show auto-load python-scripts" counterparts instead.
2370 ** "dprintf location,format,args..." creates a dynamic printf, which
2371 is basically a breakpoint that does a printf and immediately
2372 resumes your program's execution, so it is like a printf that you
2373 can insert dynamically at runtime instead of at compiletime.
2375 ** "set print symbol"
2377 Controls whether GDB attempts to display the symbol, if any,
2378 corresponding to addresses it prints. This defaults to "on", but
2379 you can set it to "off" to restore GDB's previous behavior.
2381 * Deprecated commands
2383 ** For the Renesas Super-H architecture, the "regs" command has been
2384 deprecated, and "info all-registers" should be used instead.
2388 Renesas RL78 rl78-*-elf
2389 HP OpenVMS ia64 ia64-hp-openvms*
2391 * GDBserver supports evaluation of breakpoint conditions. When
2392 support is advertised by GDBserver, GDB may be told to send the
2393 breakpoint conditions in bytecode form to GDBserver. GDBserver
2394 will only report the breakpoint trigger to GDB when its condition
2399 set mips compression
2400 show mips compression
2401 Select the compressed ISA encoding used in functions that have no symbol
2402 information available. The encoding can be set to either of:
2405 and is updated automatically from ELF file flags if available.
2407 set breakpoint condition-evaluation
2408 show breakpoint condition-evaluation
2409 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2410 GDBserver ("target"). Default option "auto" chooses the most efficient
2412 This option can improve debugger efficiency depending on the speed of the
2416 Disable auto-loading globally.
2419 Show auto-loading setting of all kinds of auto-loaded files.
2421 set auto-load gdb-scripts on|off
2422 show auto-load gdb-scripts
2423 Control auto-loading of GDB canned sequences of commands files.
2425 set auto-load python-scripts on|off
2426 show auto-load python-scripts
2427 Control auto-loading of Python script files.
2429 set auto-load local-gdbinit on|off
2430 show auto-load local-gdbinit
2431 Control loading of init file (.gdbinit) from current directory.
2433 set auto-load libthread-db on|off
2434 show auto-load libthread-db
2435 Control auto-loading of inferior specific thread debugging shared library.
2437 set auto-load scripts-directory <dir1>[:<dir2>...]
2438 show auto-load scripts-directory
2439 Set a list of directories from which to load auto-loaded scripts.
2440 Automatically loaded Python scripts and GDB scripts are located in one
2441 of the directories listed by this option.
2442 The delimiter (':' above) may differ according to the host platform.
2444 set auto-load safe-path <dir1>[:<dir2>...]
2445 show auto-load safe-path
2446 Set a list of directories from which it is safe to auto-load files.
2447 The delimiter (':' above) may differ according to the host platform.
2449 set debug auto-load on|off
2450 show debug auto-load
2451 Control display of debugging info for auto-loading the files above.
2453 set dprintf-style gdb|call|agent
2455 Control the way in which a dynamic printf is performed; "gdb"
2456 requests a GDB printf command, while "call" causes dprintf to call a
2457 function in the inferior. "agent" requests that the target agent
2458 (such as GDBserver) do the printing.
2460 set dprintf-function <expr>
2461 show dprintf-function
2462 set dprintf-channel <expr>
2463 show dprintf-channel
2464 Set the function and optional first argument to the call when using
2465 the "call" style of dynamic printf.
2467 set disconnected-dprintf on|off
2468 show disconnected-dprintf
2469 Control whether agent-style dynamic printfs continue to be in effect
2470 after GDB disconnects.
2472 * New configure options
2474 --with-auto-load-dir
2475 Configure default value for the 'set auto-load scripts-directory'
2476 setting above. It defaults to '$debugdir:$datadir/auto-load',
2477 $debugdir representing global debugging info directories (available
2478 via 'show debug-file-directory') and $datadir representing GDB's data
2479 directory (available via 'show data-directory').
2481 --with-auto-load-safe-path
2482 Configure default value for the 'set auto-load safe-path' setting
2483 above. It defaults to the --with-auto-load-dir setting.
2485 --without-auto-load-safe-path
2486 Set 'set auto-load safe-path' to '/', effectively disabling this
2489 * New remote packets
2491 z0/z1 conditional breakpoints extension
2493 The z0/z1 breakpoint insertion packets have been extended to carry
2494 a list of conditional expressions over to the remote stub depending on the
2495 condition evaluation mode. The use of this extension can be controlled
2496 via the "set remote conditional-breakpoints-packet" command.
2500 Specify the signals which the remote stub may pass to the debugged
2501 program without GDB involvement.
2503 * New command line options
2505 --init-command=FILE, -ix Like --command, -x but execute it
2506 before loading inferior.
2507 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2508 execute it before loading inferior.
2510 *** Changes in GDB 7.4
2512 * GDB now handles ambiguous linespecs more consistently; the existing
2513 FILE:LINE support has been expanded to other types of linespecs. A
2514 breakpoint will now be set on all matching locations in all
2515 inferiors, and locations will be added or removed according to
2518 * GDB now allows you to skip uninteresting functions and files when
2519 stepping with the "skip function" and "skip file" commands.
2521 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2522 and "show remote hardware-watchpoint-length-limit". These allows to
2523 set or show the maximum length limit (in bytes) of a remote
2524 target hardware watchpoint.
2526 This allows e.g. to use "unlimited" hardware watchpoints with the
2527 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2528 watchpoints are slower than real hardware watchpoints but are
2529 significantly faster than gdb software watchpoints.
2533 ** The register_pretty_printer function in module gdb.printing now takes
2534 an optional `replace' argument. If True, the new printer replaces any
2537 ** The "maint set python print-stack on|off" command has been
2538 deprecated and will be deleted in GDB 7.5.
2539 A new command: "set python print-stack none|full|message" has
2540 replaced it. Additionally, the default for "print-stack" is
2541 now "message", which just prints the error message without
2544 ** A prompt substitution hook (prompt_hook) is now available to the
2547 ** A new Python module, gdb.prompt has been added to the GDB Python
2548 modules library. This module provides functionality for
2549 escape sequences in prompts (used by set/show
2550 extended-prompt). These escape sequences are replaced by their
2551 corresponding value.
2553 ** Python commands and convenience-functions located in
2554 'data-directory'/python/gdb/command and
2555 'data-directory'/python/gdb/function are now automatically loaded
2558 ** Blocks now provide four new attributes. global_block and
2559 static_block will return the global and static blocks
2560 respectively. is_static and is_global are boolean attributes
2561 that indicate if the block is one of those two types.
2563 ** Symbols now provide the "type" attribute, the type of the symbol.
2565 ** The "gdb.breakpoint" function has been deprecated in favor of
2568 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2569 of a function. This class is based on the "finish" command
2570 available in the CLI.
2572 ** Type objects for struct and union types now allow access to
2573 the fields using standard Python dictionary (mapping) methods.
2574 For example, "some_type['myfield']" now works, as does
2575 "some_type.items()".
2577 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2580 ** A new function, "deep_items" has been added to the gdb.types
2581 module in the GDB Python modules library. This function returns
2582 an iterator over the fields of a struct or union type. Unlike
2583 the standard Python "iteritems" method, it will recursively traverse
2584 any anonymous fields.
2588 ** "*stopped" events can report several new "reason"s, such as
2591 ** Breakpoint changes are now notified using new async records, like
2592 "=breakpoint-modified".
2594 ** New command -ada-task-info.
2596 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2597 $sdir specifies the default system locations of shared libraries.
2598 $pdir specifies the directory where the libpthread used by the application
2601 GDB no longer looks in $sdir and $pdir after it has searched the directories
2602 mentioned in libthread-db-search-path. If you want to search those
2603 directories, they must be specified in libthread-db-search-path.
2604 The default value of libthread-db-search-path on GNU/Linux and Solaris
2605 systems is now "$sdir:$pdir".
2607 $pdir is not supported by gdbserver, it is currently ignored.
2608 $sdir is supported by gdbserver.
2610 * New configure option --with-iconv-bin.
2611 When using the internationalization support like the one in the GNU C
2612 library, GDB will invoke the "iconv" program to get a list of supported
2613 character sets. If this program lives in a non-standard location, one can
2614 use this option to specify where to find it.
2616 * When natively debugging programs on PowerPC BookE processors running
2617 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2618 watchpoints, which specify a mask in addition to an address to watch.
2619 The mask specifies that some bits of an address (the bits which are
2620 reset in the mask) should be ignored when matching the address accessed
2621 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2622 section in the user manual for more details.
2624 * The new option --once causes GDBserver to stop listening for connections once
2625 the first connection is made. The listening port used by GDBserver will
2626 become available after that.
2628 * New commands "info macros" and "alias" have been added.
2630 * New function parameters suffix @entry specifies value of function parameter
2631 at the time the function got called. Entry values are available only since
2637 "!" is now an alias of the "shell" command.
2638 Note that no space is needed between "!" and SHELL COMMAND.
2642 watch EXPRESSION mask MASK_VALUE
2643 The watch command now supports the mask argument which allows creation
2644 of masked watchpoints, if the current architecture supports this feature.
2646 info auto-load-scripts [REGEXP]
2647 This command was formerly named "maintenance print section-scripts".
2648 It is now generally useful and is no longer a maintenance-only command.
2650 info macro [-all] [--] MACRO
2651 The info macro command has new options `-all' and `--'. The first for
2652 printing all definitions of a macro. The second for explicitly specifying
2653 the end of arguments and the beginning of the macro name in case the macro
2654 name starts with a hyphen.
2656 collect[/s] EXPRESSIONS
2657 The tracepoint collect command now takes an optional modifier "/s"
2658 that directs it to dereference pointer-to-character types and
2659 collect the bytes of memory up to a zero byte. The behavior is
2660 similar to what you see when you use the regular print command on a
2661 string. An optional integer following the "/s" sets a bound on the
2662 number of bytes that will be collected.
2665 The trace start command now interprets any supplied arguments as a
2666 note to be recorded with the trace run, with an effect similar to
2667 setting the variable trace-notes.
2670 The trace stop command now interprets any arguments as a note to be
2671 mentioned along with the tstatus report that the trace was stopped
2672 with a command. The effect is similar to setting the variable
2675 * Tracepoints can now be enabled and disabled at any time after a trace
2676 experiment has been started using the standard "enable" and "disable"
2677 commands. It is now possible to start a trace experiment with no enabled
2678 tracepoints; GDB will display a warning, but will allow the experiment to
2679 begin, assuming that tracepoints will be enabled as needed while the trace
2682 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2683 locations with 4-byte instructions, when they were previously
2684 limited to locations with instructions of 5 bytes or longer.
2688 set debug dwarf2-read
2689 show debug dwarf2-read
2690 Turns on or off display of debugging messages related to reading
2691 DWARF debug info. The default is off.
2693 set debug symtab-create
2694 show debug symtab-create
2695 Turns on or off display of debugging messages related to symbol table
2696 creation. The default is off.
2699 show extended-prompt
2700 Set the GDB prompt, and allow escape sequences to be inserted to
2701 display miscellaneous information (see 'help set extended-prompt'
2702 for the list of sequences). This prompt (and any information
2703 accessed through the escape sequences) is updated every time the
2704 prompt is displayed.
2706 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2707 show print entry-values
2708 Set printing of frame argument values at function entry. In some cases
2709 GDB can determine the value of function argument which was passed by the
2710 function caller, even if the value was modified inside the called function.
2712 set debug entry-values
2713 show debug entry-values
2714 Control display of debugging info for determining frame argument values at
2715 function entry and virtual tail call frames.
2717 set basenames-may-differ
2718 show basenames-may-differ
2719 Set whether a source file may have multiple base names.
2720 (A "base name" is the name of a file with the directory part removed.
2721 Example: The base name of "/home/user/hello.c" is "hello.c".)
2722 If set, GDB will canonicalize file names (e.g., expand symlinks)
2723 before comparing them. Canonicalization is an expensive operation,
2724 but it allows the same file be known by more than one base name.
2725 If not set (the default), all source files are assumed to have just
2726 one base name, and gdb will do file name comparisons more efficiently.
2732 Set a user name and notes for the current and any future trace runs.
2733 This is useful for long-running and/or disconnected traces, to
2734 inform others (or yourself) as to who is running the trace, supply
2735 contact information, or otherwise explain what is going on.
2737 set trace-stop-notes
2738 show trace-stop-notes
2739 Set a note attached to the trace run, that is displayed when the
2740 trace has been stopped by a tstop command. This is useful for
2741 instance as an explanation, if you are stopping a trace run that was
2742 started by someone else.
2744 * New remote packets
2748 Dynamically enable a tracepoint in a started trace experiment.
2752 Dynamically disable a tracepoint in a started trace experiment.
2756 Set the user and notes of the trace run.
2760 Query the current status of a tracepoint.
2764 Query the minimum length of instruction at which a fast tracepoint may
2767 * Dcache size (number of lines) and line-size are now runtime-configurable
2768 via "set dcache line" and "set dcache line-size" commands.
2772 Texas Instruments TMS320C6x tic6x-*-*
2776 Renesas RL78 rl78-*-elf
2778 *** Changes in GDB 7.3.1
2780 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2782 *** Changes in GDB 7.3
2784 * GDB has a new command: "thread find [REGEXP]".
2785 It finds the thread id whose name, target id, or thread extra info
2786 matches the given regular expression.
2788 * The "catch syscall" command now works on mips*-linux* targets.
2790 * The -data-disassemble MI command now supports modes 2 and 3 for
2791 dumping the instruction opcodes.
2793 * New command line options
2795 -data-directory DIR Specify DIR as the "data-directory".
2796 This is mostly for testing purposes.
2798 * The "maint set python auto-load on|off" command has been renamed to
2799 "set auto-load-scripts on|off".
2801 * GDB has a new command: "set directories".
2802 It is like the "dir" command except that it replaces the
2803 source path list instead of augmenting it.
2805 * GDB now understands thread names.
2807 On GNU/Linux, "info threads" will display the thread name as set by
2808 prctl or pthread_setname_np.
2810 There is also a new command, "thread name", which can be used to
2811 assign a name internally for GDB to display.
2814 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2815 has been integrated into GDB.
2819 ** The function gdb.Write now accepts an optional keyword 'stream'.
2820 This keyword, when provided, will direct the output to either
2821 stdout, stderr, or GDB's logging output.
2823 ** Parameters can now be be sub-classed in Python, and in particular
2824 you may implement the get_set_doc and get_show_doc functions.
2825 This improves how Parameter set/show documentation is processed
2826 and allows for more dynamic content.
2828 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2829 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2830 have an is_valid method.
2832 ** Breakpoints can now be sub-classed in Python, and in particular
2833 you may implement a 'stop' function that is executed each time
2834 the inferior reaches that breakpoint.
2836 ** New function gdb.lookup_global_symbol looks up a global symbol.
2838 ** GDB values in Python are now callable if the value represents a
2839 function. For example, if 'some_value' represents a function that
2840 takes two integer parameters and returns a value, you can call
2841 that function like so:
2843 result = some_value (10,20)
2845 ** Module gdb.types has been added.
2846 It contains a collection of utilities for working with gdb.Types objects:
2847 get_basic_type, has_field, make_enum_dict.
2849 ** Module gdb.printing has been added.
2850 It contains utilities for writing and registering pretty-printers.
2851 New classes: PrettyPrinter, SubPrettyPrinter,
2852 RegexpCollectionPrettyPrinter.
2853 New function: register_pretty_printer.
2855 ** New commands "info pretty-printers", "enable pretty-printer" and
2856 "disable pretty-printer" have been added.
2858 ** gdb.parameter("directories") is now available.
2860 ** New function gdb.newest_frame returns the newest frame in the
2863 ** The gdb.InferiorThread class has a new "name" attribute. This
2864 holds the thread's name.
2866 ** Python Support for Inferior events.
2867 Python scripts can add observers to be notified of events
2868 occurring in the process being debugged.
2869 The following events are currently supported:
2870 - gdb.events.cont Continue event.
2871 - gdb.events.exited Inferior exited event.
2872 - gdb.events.stop Signal received, and Breakpoint hit events.
2876 ** GDB now puts template parameters in scope when debugging in an
2877 instantiation. For example, if you have:
2879 template<int X> int func (void) { return X; }
2881 then if you step into func<5>, "print X" will show "5". This
2882 feature requires proper debuginfo support from the compiler; it
2883 was added to GCC 4.5.
2885 ** The motion commands "next", "finish", "until", and "advance" now
2886 work better when exceptions are thrown. In particular, GDB will
2887 no longer lose control of the inferior; instead, the GDB will
2888 stop the inferior at the point at which the exception is caught.
2889 This functionality requires a change in the exception handling
2890 code that was introduced in GCC 4.5.
2892 * GDB now follows GCC's rules on accessing volatile objects when
2893 reading or writing target state during expression evaluation.
2894 One notable difference to prior behavior is that "print x = 0"
2895 no longer generates a read of x; the value of the assignment is
2896 now always taken directly from the value being assigned.
2898 * GDB now has some support for using labels in the program's source in
2899 linespecs. For instance, you can use "advance label" to continue
2900 execution to a label.
2902 * GDB now has support for reading and writing a new .gdb_index
2903 section. This section holds a fast index of DWARF debugging
2904 information and can be used to greatly speed up GDB startup and
2905 operation. See the documentation for `save gdb-index' for details.
2907 * The "watch" command now accepts an optional "-location" argument.
2908 When used, this causes GDB to watch the memory referred to by the
2909 expression. Such a watchpoint is never deleted due to it going out
2912 * GDB now supports thread debugging of core dumps on GNU/Linux.
2914 GDB now activates thread debugging using the libthread_db library
2915 when debugging GNU/Linux core dumps, similarly to when debugging
2916 live processes. As a result, when debugging a core dump file, GDB
2917 is now able to display pthread_t ids of threads. For example, "info
2918 threads" shows the same output as when debugging the process when it
2919 was live. In earlier releases, you'd see something like this:
2922 * 1 LWP 6780 main () at main.c:10
2924 While now you see this:
2927 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2929 It is also now possible to inspect TLS variables when debugging core
2932 When debugging a core dump generated on a machine other than the one
2933 used to run GDB, you may need to point GDB at the correct
2934 libthread_db library with the "set libthread-db-search-path"
2935 command. See the user manual for more details on this command.
2937 * When natively debugging programs on PowerPC BookE processors running
2938 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2939 which stop execution of the inferior whenever it executes an instruction
2940 at any address within the specified range. See the "PowerPC Embedded"
2941 section in the user manual for more details.
2943 * New features in the GDB remote stub, GDBserver
2945 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2946 and i686 LynxOS (version 5.x).
2948 ** GDBserver is now supported on Blackfin Linux.
2950 * New native configurations
2952 ia64 HP-UX ia64-*-hpux*
2956 Analog Devices, Inc. Blackfin Processor bfin-*
2958 * Ada task switching is now supported on sparc-elf targets when
2959 debugging a program using the Ravenscar Profile. For more information,
2960 see the "Tasking Support when using the Ravenscar Profile" section
2961 in the GDB user manual.
2963 * Guile support was removed.
2965 * New features in the GNU simulator
2967 ** The --map-info flag lists all known core mappings.
2969 ** CFI flashes may be simulated via the "cfi" device.
2971 *** Changes in GDB 7.2
2973 * Shared library support for remote targets by default
2975 When GDB is configured for a generic, non-OS specific target, like
2976 for example, --target=arm-eabi or one of the many *-*-elf targets,
2977 GDB now queries remote stubs for loaded shared libraries using the
2978 `qXfer:libraries:read' packet. Previously, shared library support
2979 was always disabled for such configurations.
2983 ** Argument Dependent Lookup (ADL)
2985 In C++ ADL lookup directs function search to the namespaces of its
2986 arguments even if the namespace has not been imported.
2996 Here the compiler will search for `foo' in the namespace of 'b'
2997 and find A::foo. GDB now supports this. This construct is commonly
2998 used in the Standard Template Library for operators.
3000 ** Improved User Defined Operator Support
3002 In addition to member operators, GDB now supports lookup of operators
3003 defined in a namespace and imported with a `using' directive, operators
3004 defined in the global scope, operators imported implicitly from an
3005 anonymous namespace, and the ADL operators mentioned in the previous
3007 GDB now also supports proper overload resolution for all the previously
3008 mentioned flavors of operators.
3010 ** static const class members
3012 Printing of static const class members that are initialized in the
3013 class definition has been fixed.
3015 * Windows Thread Information Block access.
3017 On Windows targets, GDB now supports displaying the Windows Thread
3018 Information Block (TIB) structure. This structure is visible either
3019 by using the new command `info w32 thread-information-block' or, by
3020 dereferencing the new convenience variable named `$_tlb', a
3021 thread-specific pointer to the TIB. This feature is also supported
3022 when remote debugging using GDBserver.
3024 * Static tracepoints
3026 Static tracepoints are calls in the user program into a tracing
3027 library. One such library is a port of the LTTng kernel tracer to
3028 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3029 When debugging with GDBserver, GDB now supports combining the GDB
3030 tracepoint machinery with such libraries. For example: the user can
3031 use GDB to probe a static tracepoint marker (a call from the user
3032 program into the tracing library) with the new "strace" command (see
3033 "New commands" below). This creates a "static tracepoint" in the
3034 breakpoint list, that can be manipulated with the same feature set
3035 as fast and regular tracepoints. E.g., collect registers, local and
3036 global variables, collect trace state variables, and define
3037 tracepoint conditions. In addition, the user can collect extra
3038 static tracepoint marker specific data, by collecting the new
3039 $_sdata internal variable. When analyzing the trace buffer, you can
3040 inspect $_sdata like any other variable available to GDB. For more
3041 information, see the "Tracepoints" chapter in GDB user manual. New
3042 remote packets have been defined to support static tracepoints, see
3043 the "New remote packets" section below.
3045 * Better reconstruction of tracepoints after disconnected tracing
3047 GDB will attempt to download the original source form of tracepoint
3048 definitions when starting a trace run, and then will upload these
3049 upon reconnection to the target, resulting in a more accurate
3050 reconstruction of the tracepoints that are in use on the target.
3054 You can now exercise direct control over the ways that GDB can
3055 affect your program. For instance, you can disallow the setting of
3056 breakpoints, so that the program can run continuously (assuming
3057 non-stop mode). In addition, the "observer" variable is available
3058 to switch all of the different controls; in observer mode, GDB
3059 cannot affect the target's behavior at all, which is useful for
3060 tasks like diagnosing live systems in the field.
3062 * The new convenience variable $_thread holds the number of the
3065 * New remote packets
3069 Return the address of the Windows Thread Information Block of a given thread.
3073 In response to several of the tracepoint packets, the target may now
3074 also respond with a number of intermediate `qRelocInsn' request
3075 packets before the final result packet, to have GDB handle
3076 relocating an instruction to execute at a different address. This
3077 is particularly useful for stubs that support fast tracepoints. GDB
3078 reports support for this feature in the qSupported packet.
3082 List static tracepoint markers in the target program.
3086 List static tracepoint markers at a given address in the target
3089 qXfer:statictrace:read
3091 Read the static trace data collected (by a `collect $_sdata'
3092 tracepoint action). The remote stub reports support for this packet
3093 to gdb's qSupported query.
3097 Send the current settings of GDB's permission flags.
3101 Send part of the source (textual) form of a tracepoint definition,
3102 which includes location, conditional, and action list.
3104 * The source command now accepts a -s option to force searching for the
3105 script in the source search path even if the script name specifies
3108 * New features in the GDB remote stub, GDBserver
3110 - GDBserver now support tracepoints (including fast tracepoints, and
3111 static tracepoints). The feature is currently supported by the
3112 i386-linux and amd64-linux builds. See the "Tracepoints support
3113 in gdbserver" section in the manual for more information.
3115 GDBserver JIT compiles the tracepoint's conditional agent
3116 expression bytecode into native code whenever possible for low
3117 overhead dynamic tracepoints conditionals. For such tracepoints,
3118 an expression that examines program state is evaluated when the
3119 tracepoint is reached, in order to determine whether to capture
3120 trace data. If the condition is simple and false, processing the
3121 tracepoint finishes very quickly and no data is gathered.
3123 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3124 for static tracepoints support.
3126 - GDBserver now supports x86_64 Windows 64-bit debugging.
3128 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3129 it understands register description.
3131 * The --batch flag now disables pagination and queries.
3133 * X86 general purpose registers
3135 GDB now supports reading/writing byte, word and double-word x86
3136 general purpose registers directly. This means you can use, say,
3137 $ah or $ax to refer, respectively, to the byte register AH and
3138 16-bit word register AX that are actually portions of the 32-bit
3139 register EAX or 64-bit register RAX.
3141 * The `commands' command now accepts a range of breakpoints to modify.
3142 A plain `commands' following a command that creates multiple
3143 breakpoints affects all the breakpoints set by that command. This
3144 applies to breakpoints set by `rbreak', and also applies when a
3145 single `break' command creates multiple breakpoints (e.g.,
3146 breakpoints on overloaded c++ functions).
3148 * The `rbreak' command now accepts a filename specification as part of
3149 its argument, limiting the functions selected by the regex to those
3150 in the specified file.
3152 * Support for remote debugging Windows and SymbianOS shared libraries
3153 from Unix hosts has been improved. Non Windows GDB builds now can
3154 understand target reported file names that follow MS-DOS based file
3155 system semantics, such as file names that include drive letters and
3156 use the backslash character as directory separator. This makes it
3157 possible to transparently use the "set sysroot" and "set
3158 solib-search-path" on Unix hosts to point as host copies of the
3159 target's shared libraries. See the new command "set
3160 target-file-system-kind" described below, and the "Commands to
3161 specify files" section in the user manual for more information.
3165 eval template, expressions...
3166 Convert the values of one or more expressions under the control
3167 of the string template to a command line, and call it.
3169 set target-file-system-kind unix|dos-based|auto
3170 show target-file-system-kind
3171 Set or show the assumed file system kind for target reported file
3174 save breakpoints <filename>
3175 Save all current breakpoint definitions to a file suitable for use
3176 in a later debugging session. To read the saved breakpoint
3177 definitions, use the `source' command.
3179 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3182 info static-tracepoint-markers
3183 Display information about static tracepoint markers in the target.
3185 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3186 Define a static tracepoint by probing a marker at the given
3187 function, line, address, or marker ID.
3191 Enable and disable observer mode.
3193 set may-write-registers on|off
3194 set may-write-memory on|off
3195 set may-insert-breakpoints on|off
3196 set may-insert-tracepoints on|off
3197 set may-insert-fast-tracepoints on|off
3198 set may-interrupt on|off
3199 Set individual permissions for GDB effects on the target. Note that
3200 some of these settings can have undesirable or surprising
3201 consequences, particularly when changed in the middle of a session.
3202 For instance, disabling the writing of memory can prevent
3203 breakpoints from being inserted, cause single-stepping to fail, or
3204 even crash your program, if you disable after breakpoints have been
3205 inserted. However, GDB should not crash.
3207 set record memory-query on|off
3208 show record memory-query
3209 Control whether to stop the inferior if memory changes caused
3210 by an instruction cannot be recorded.
3215 The disassemble command now supports "start,+length" form of two arguments.
3219 ** GDB now provides a new directory location, called the python directory,
3220 where Python scripts written for GDB can be installed. The location
3221 of that directory is <data-directory>/python, where <data-directory>
3222 is the GDB data directory. For more details, see section `Scripting
3223 GDB using Python' in the manual.
3225 ** The GDB Python API now has access to breakpoints, symbols, symbol
3226 tables, program spaces, inferiors, threads and frame's code blocks.
3227 Additionally, GDB Parameters can now be created from the API, and
3228 manipulated via set/show in the CLI.
3230 ** New functions gdb.target_charset, gdb.target_wide_charset,
3231 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3233 ** New exception gdb.GdbError.
3235 ** Pretty-printers are now also looked up in the current program space.
3237 ** Pretty-printers can now be individually enabled and disabled.
3239 ** GDB now looks for names of Python scripts to auto-load in a
3240 special section named `.debug_gdb_scripts', in addition to looking
3241 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3243 * Tracepoint actions were unified with breakpoint commands. In particular,
3244 there are no longer differences in "info break" output for breakpoints and
3245 tracepoints and the "commands" command can be used for both tracepoints and
3246 regular breakpoints.
3250 ARM Symbian arm*-*-symbianelf*
3252 * D language support.
3253 GDB now supports debugging programs written in the D programming
3256 * GDB now supports the extended ptrace interface for PowerPC which is
3257 available since Linux kernel version 2.6.34. This automatically enables
3258 any hardware breakpoints and additional hardware watchpoints available in
3259 the processor. The old ptrace interface exposes just one hardware
3260 watchpoint and no hardware breakpoints.
3262 * GDB is now able to use the Data Value Compare (DVC) register available on
3263 embedded PowerPC processors to implement in hardware simple watchpoint
3264 conditions of the form:
3266 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3268 This works in native GDB running on Linux kernels with the extended ptrace
3269 interface mentioned above.
3271 *** Changes in GDB 7.1
3275 ** Namespace Support
3277 GDB now supports importing of namespaces in C++. This enables the
3278 user to inspect variables from imported namespaces. Support for
3279 namepace aliasing has also been added. So, if a namespace is
3280 aliased in the current scope (e.g. namepace C=A; ) the user can
3281 print variables using the alias (e.g. (gdb) print C::x).
3285 All known bugs relating to the printing of virtual base class were
3286 fixed. It is now possible to call overloaded static methods using a
3291 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3292 and reinterpret_cast<> are now handled by the C++ expression parser.
3296 Xilinx MicroBlaze microblaze-*-*
3301 Xilinx MicroBlaze microblaze
3304 * Multi-program debugging.
3306 GDB now has support for multi-program (a.k.a. multi-executable or
3307 multi-exec) debugging. This allows for debugging multiple inferiors
3308 simultaneously each running a different program under the same GDB
3309 session. See "Debugging Multiple Inferiors and Programs" in the
3310 manual for more information. This implied some user visible changes
3311 in the multi-inferior support. For example, "info inferiors" now
3312 lists inferiors that are not running yet or that have exited
3313 already. See also "New commands" and "New options" below.
3315 * New tracing features
3317 GDB's tracepoint facility now includes several new features:
3319 ** Trace state variables
3321 GDB tracepoints now include support for trace state variables, which
3322 are variables managed by the target agent during a tracing
3323 experiment. They are useful for tracepoints that trigger each
3324 other, so for instance one tracepoint can count hits in a variable,
3325 and then a second tracepoint has a condition that is true when the
3326 count reaches a particular value. Trace state variables share the
3327 $-syntax of GDB convenience variables, and can appear in both
3328 tracepoint actions and condition expressions. Use the "tvariable"
3329 command to create, and "info tvariables" to view; see "Trace State
3330 Variables" in the manual for more detail.
3334 GDB now includes an option for defining fast tracepoints, which
3335 targets may implement more efficiently, such as by installing a jump
3336 into the target agent rather than a trap instruction. The resulting
3337 speedup can be by two orders of magnitude or more, although the
3338 tradeoff is that some program locations on some target architectures
3339 might not allow fast tracepoint installation, for instance if the
3340 instruction to be replaced is shorter than the jump. To request a
3341 fast tracepoint, use the "ftrace" command, with syntax identical to
3342 the regular trace command.
3344 ** Disconnected tracing
3346 It is now possible to detach GDB from the target while it is running
3347 a trace experiment, then reconnect later to see how the experiment
3348 is going. In addition, a new variable disconnected-tracing lets you
3349 tell the target agent whether to continue running a trace if the
3350 connection is lost unexpectedly.
3354 GDB now has the ability to save the trace buffer into a file, and
3355 then use that file as a target, similarly to you can do with
3356 corefiles. You can select trace frames, print data that was
3357 collected in them, and use tstatus to display the state of the
3358 tracing run at the moment that it was saved. To create a trace
3359 file, use "tsave <filename>", and to use it, do "target tfile
3362 ** Circular trace buffer
3364 You can ask the target agent to handle the trace buffer as a
3365 circular buffer, discarding the oldest trace frames to make room for
3366 newer ones, by setting circular-trace-buffer to on. This feature may
3367 not be available for all target agents.
3372 The disassemble command, when invoked with two arguments, now requires
3373 the arguments to be comma-separated.
3376 The info variables command now displays variable definitions. Files
3377 which only declare a variable are not shown.
3380 The source command is now capable of sourcing Python scripts.
3381 This feature is dependent on the debugger being build with Python
3384 Related to this enhancement is also the introduction of a new command
3385 "set script-extension" (see below).
3387 * New commands (for set/show, see "New options" below)
3389 record save [<FILENAME>]
3390 Save a file (in core file format) containing the process record
3391 execution log for replay debugging at a later time.
3393 record restore <FILENAME>
3394 Restore the process record execution log that was saved at an
3395 earlier time, for replay debugging.
3397 add-inferior [-copies <N>] [-exec <FILENAME>]
3400 clone-inferior [-copies <N>] [ID]
3401 Make a new inferior ready to execute the same program another
3402 inferior has loaded.
3407 maint info program-spaces
3408 List the program spaces loaded into GDB.
3410 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3411 show remote interrupt-sequence
3412 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3413 as the sequence to the remote target in order to interrupt the execution.
3414 Ctrl-C is a default. Some system prefers BREAK which is high level of
3415 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3416 Magic SysRq g. It is BREAK signal and character 'g'.
3418 set remote interrupt-on-connect [on | off]
3419 show remote interrupt-on-connect
3420 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3421 remote target when gdb connects to it. This is needed when you debug
3424 set remotebreak [on | off]
3426 Deprecated. Use "set/show remote interrupt-sequence" instead.
3428 tvariable $NAME [ = EXP ]
3429 Create or modify a trace state variable.
3432 List trace state variables and their values.
3434 delete tvariable $NAME ...
3435 Delete one or more trace state variables.
3438 Evaluate the given expressions without collecting anything into the
3439 trace buffer. (Valid in tracepoint actions only.)
3441 ftrace FN / FILE:LINE / *ADDR
3442 Define a fast tracepoint at the given function, line, or address.
3444 * New expression syntax
3446 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3447 GDB now parses 0b101010 identically with 42.
3451 set follow-exec-mode new|same
3452 show follow-exec-mode
3453 Control whether GDB reuses the same inferior across an exec call or
3454 creates a new one. This is useful to be able to restart the old
3455 executable after the inferior having done an exec call.
3457 set default-collect EXPR, ...
3458 show default-collect
3459 Define a list of expressions to be collected at each tracepoint.
3460 This is a useful way to ensure essential items are not overlooked,
3461 such as registers or a critical global variable.
3463 set disconnected-tracing
3464 show disconnected-tracing
3465 If set to 1, the target is instructed to continue tracing if it
3466 loses its connection to GDB. If 0, the target is to stop tracing
3469 set circular-trace-buffer
3470 show circular-trace-buffer
3471 If set to on, the target is instructed to use a circular trace buffer
3472 and discard the oldest trace frames instead of stopping the trace due
3473 to a full trace buffer. If set to off, the trace stops when the buffer
3474 fills up. Some targets may not support this.
3476 set script-extension off|soft|strict
3477 show script-extension
3478 If set to "off", the debugger does not perform any script language
3479 recognition, and all sourced files are assumed to be GDB scripts.
3480 If set to "soft" (the default), files are sourced according to
3481 filename extension, falling back to GDB scripts if the first
3483 If set to "strict", files are sourced according to filename extension.
3485 set ada trust-PAD-over-XVS on|off
3486 show ada trust-PAD-over-XVS
3487 If off, activate a workaround against a bug in the debugging information
3488 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3489 the GCC sources for more information about the GNAT encoding and
3490 PAD types in particular). It is always safe to set this option to
3491 off, but this introduces a slight performance penalty. The default
3494 * Python API Improvements
3496 ** GDB provides the new class gdb.LazyString. This is useful in
3497 some pretty-printing cases. The new method gdb.Value.lazy_string
3498 provides a simple way to create objects of this type.
3500 ** The fields returned by gdb.Type.fields now have an
3501 `is_base_class' attribute.
3503 ** The new method gdb.Type.range returns the range of an array type.
3505 ** The new method gdb.parse_and_eval can be used to parse and
3506 evaluate an expression.
3508 * New remote packets
3511 Define a trace state variable.
3514 Get the current value of a trace state variable.
3517 Set desired tracing behavior upon disconnection.
3520 Set the trace buffer to be linear or circular.
3523 Get data about the tracepoints currently in use.
3527 Process record now works correctly with hardware watchpoints.
3529 Multiple bug fixes have been made to the mips-irix port, making it
3530 much more reliable. In particular:
3531 - Debugging threaded applications is now possible again. Previously,
3532 GDB would hang while starting the program, or while waiting for
3533 the program to stop at a breakpoint.
3534 - Attaching to a running process no longer hangs.
3535 - An error occurring while loading a core file has been fixed.
3536 - Changing the value of the PC register now works again. This fixes
3537 problems observed when using the "jump" command, or when calling
3538 a function from GDB, or even when assigning a new value to $pc.
3539 - With the "finish" and "return" commands, the return value for functions
3540 returning a small array is now correctly printed.
3541 - It is now possible to break on shared library code which gets executed
3542 during a shared library init phase (code executed while executing
3543 their .init section). Previously, the breakpoint would have no effect.
3544 - GDB is now able to backtrace through the signal handler for
3545 non-threaded programs.
3547 PIE (Position Independent Executable) programs debugging is now supported.
3548 This includes debugging execution of PIC (Position Independent Code) shared
3549 libraries although for that, it should be possible to run such libraries as an
3552 *** Changes in GDB 7.0
3554 * GDB now has an interface for JIT compilation. Applications that
3555 dynamically generate code can create symbol files in memory and register
3556 them with GDB. For users, the feature should work transparently, and
3557 for JIT developers, the interface is documented in the GDB manual in the
3558 "JIT Compilation Interface" chapter.
3560 * Tracepoints may now be conditional. The syntax is as for
3561 breakpoints; either an "if" clause appended to the "trace" command,
3562 or the "condition" command is available. GDB sends the condition to
3563 the target for evaluation using the same bytecode format as is used
3564 for tracepoint actions.
3566 * The disassemble command now supports: an optional /r modifier, print the
3567 raw instructions in hex as well as in symbolic form, and an optional /m
3568 modifier to print mixed source+assembly.
3570 * Process record and replay
3572 In a architecture environment that supports ``process record and
3573 replay'', ``process record and replay'' target can record a log of
3574 the process execution, and replay it with both forward and reverse
3577 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3578 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3579 set execution-direction {forward|reverse}, for targets that support
3582 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3583 feature is available with a native GDB running on kernel version
3586 * GDB now has support for multi-byte and wide character sets on the
3587 target. Strings whose character type is wchar_t, char16_t, or
3588 char32_t are now correctly printed. GDB supports wide- and unicode-
3589 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3590 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3591 `printf'. This feature requires iconv to work properly; if your
3592 system does not have a working iconv, GDB can use GNU libiconv. See
3593 the installation instructions for more information.
3595 * GDB now supports automatic retrieval of shared library files from
3596 remote targets. To use this feature, specify a system root that begins
3597 with the `remote:' prefix, either via the `set sysroot' command or via
3598 the `--with-sysroot' configure-time option.
3600 * "info sharedlibrary" now takes an optional regex of libraries to show,
3601 and it now reports if a shared library has no debugging information.
3603 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3604 now complete on file names.
3606 * When completing in expressions, gdb will attempt to limit
3607 completions to allowable structure or union fields, where appropriate.
3608 For instance, consider:
3610 # struct example { int f1; double f2; };
3611 # struct example variable;
3614 If the user types TAB at the end of this command line, the available
3615 completions will be "f1" and "f2".
3617 * Inlined functions are now supported. They show up in backtraces, and
3618 the "step", "next", and "finish" commands handle them automatically.
3620 * GDB now supports the token-splicing (##) and stringification (#)
3621 operators when expanding macros. It also supports variable-arity
3624 * GDB now supports inspecting extra signal information, exported by
3625 the new $_siginfo convenience variable. The feature is currently
3626 implemented on linux ARM, i386 and amd64.
3628 * GDB can now display the VFP floating point registers and NEON vector
3629 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3630 can provide these registers (requires Linux 2.6.30 or later). Remote
3631 and simulator targets may also provide them.
3633 * New remote packets
3636 Search memory for a sequence of bytes.
3639 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3640 operation over reliable transport links. Use of this packet is
3641 controlled by the `set remote noack-packet' command.
3644 Kill the process with the specified process ID. Use this in preference
3645 to `k' when multiprocess protocol extensions are supported.
3648 Obtains additional operating system information
3652 Read or write additional signal information.
3654 * Removed remote protocol undocumented extension
3656 An undocumented extension to the remote protocol's `S' stop reply
3657 packet that permited the stub to pass a process id was removed.
3658 Remote servers should use the `T' stop reply packet instead.
3660 * GDB now supports multiple function calling conventions according to the
3661 DWARF-2 DW_AT_calling_convention function attribute.
3663 * The SH target utilizes the aforementioned change to distinguish between gcc
3664 and Renesas calling convention. It also adds the new CLI commands
3665 `set/show sh calling-convention'.
3667 * GDB can now read compressed debug sections, as produced by GNU gold
3668 with the --compress-debug-sections=zlib flag.
3670 * 64-bit core files are now supported on AIX.
3672 * Thread switching is now supported on Tru64.
3674 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3675 which will be allocated using malloc later in program execution.
3677 * The qXfer:libraries:read remote procotol packet now allows passing a
3678 list of section offsets.
3680 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3681 conditions handling signals delivered during attach or thread creation
3682 have also been fixed.
3684 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3685 From the user's standpoint, all unqualified instances of True and False
3686 are treated as the standard definitions, regardless of context.
3688 * GDB now parses C++ symbol and type names more flexibly. For
3691 template<typename T> class C { };
3694 GDB will now correctly handle all of:
3696 ptype C<char const *>
3697 ptype C<char const*>
3698 ptype C<const char *>
3699 ptype C<const char*>
3701 * New features in the GDB remote stub, gdbserver
3703 - The "--wrapper" command-line argument tells gdbserver to use a
3704 wrapper program to launch programs for debugging.
3706 - On PowerPC and S/390 targets, it is now possible to use a single
3707 gdbserver executable to debug both 32-bit and 64-bit programs.
3708 (This requires gdbserver itself to be built as a 64-bit executable.)
3710 - gdbserver uses the new noack protocol mode for TCP connections to
3711 reduce communications latency, if also supported and enabled in GDB.
3713 - Support for the sparc64-linux-gnu target is now included in
3716 - The amd64-linux build of gdbserver now supports debugging both
3717 32-bit and 64-bit programs.
3719 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3720 now support hardware watchpoints, and will use them automatically
3725 GDB now has support for scripting using Python. Whether this is
3726 available is determined at configure time.
3728 New GDB commands can now be written in Python.
3730 * Ada tasking support
3732 Ada tasks can now be inspected in GDB. The following commands have
3736 Print the list of Ada tasks.
3738 Print detailed information about task number N.
3740 Print the task number of the current task.
3742 Switch the context of debugging to task number N.
3744 * Support for user-defined prefixed commands. The "define" command can
3745 add new commands to existing prefixes, e.g. "target".
3747 * Multi-inferior, multi-process debugging.
3749 GDB now has generalized support for multi-inferior debugging. See
3750 "Debugging Multiple Inferiors" in the manual for more information.
3751 Although availability still depends on target support, the command
3752 set is more uniform now. The GNU/Linux specific multi-forks support
3753 has been migrated to this new framework. This implied some user
3754 visible changes; see "New commands" and also "Removed commands"
3757 * Target descriptions can now describe the target OS ABI. See the
3758 "Target Description Format" section in the user manual for more
3761 * Target descriptions can now describe "compatible" architectures
3762 to indicate that the target can execute applications for a different
3763 architecture in addition to those for the main target architecture.
3764 See the "Target Description Format" section in the user manual for
3767 * Multi-architecture debugging.
3769 GDB now includes general supports for debugging applications on
3770 hybrid systems that use more than one single processor architecture
3771 at the same time. Each such hybrid architecture still requires
3772 specific support to be added. The only hybrid architecture supported
3773 in this version of GDB is the Cell Broadband Engine.
3775 * GDB now supports integrated debugging of Cell/B.E. applications that
3776 use both the PPU and SPU architectures. To enable support for hybrid
3777 Cell/B.E. debugging, you need to configure GDB to support both the
3778 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3779 --enable-targets configure option.
3781 * Non-stop mode debugging.
3783 For some targets, GDB now supports an optional mode of operation in
3784 which you can examine stopped threads while other threads continue
3785 to execute freely. This is referred to as non-stop mode, with the
3786 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3787 section in the user manual for more information.
3789 To be able to support remote non-stop debugging, a remote stub needs
3790 to implement the non-stop mode remote protocol extensions, as
3791 described in the "Remote Non-Stop" section of the user manual. The
3792 GDB remote stub, gdbserver, has been adjusted to support these
3793 extensions on linux targets.
3795 * New commands (for set/show, see "New options" below)
3797 catch syscall [NAME(S) | NUMBER(S)]
3798 Catch system calls. Arguments, which should be names of system
3799 calls or their numbers, mean catch only those syscalls. Without
3800 arguments, every syscall will be caught. When the inferior issues
3801 any of the specified syscalls, GDB will stop and announce the system
3802 call, both when it is called and when its call returns. This
3803 feature is currently available with a native GDB running on the
3804 Linux Kernel, under the following architectures: x86, x86_64,
3805 PowerPC and PowerPC64.
3807 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3809 Search memory for a sequence of bytes.
3811 maint set python print-stack
3812 maint show python print-stack
3813 Show a stack trace when an error is encountered in a Python script.
3816 Invoke CODE by passing it to the Python interpreter.
3821 These allow macros to be defined, undefined, and listed
3825 Show operating system information about processes.
3828 List the inferiors currently under GDB's control.
3831 Switch focus to inferior number NUM.
3834 Detach from inferior number NUM.
3837 Kill inferior number NUM.
3841 set spu stop-on-load
3842 show spu stop-on-load
3843 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3845 set spu auto-flush-cache
3846 show spu auto-flush-cache
3847 Control whether to automatically flush the software-managed cache
3848 during Cell/B.E. debugging.
3850 set sh calling-convention
3851 show sh calling-convention
3852 Control the calling convention used when calling SH target functions.
3855 show debug timestamp
3856 Control display of timestamps with GDB debugging output.
3858 set disassemble-next-line
3859 show disassemble-next-line
3860 Control display of disassembled source lines or instructions when
3863 set remote noack-packet
3864 show remote noack-packet
3865 Set/show the use of remote protocol QStartNoAckMode packet. See above
3866 under "New remote packets."
3868 set remote query-attached-packet
3869 show remote query-attached-packet
3870 Control use of remote protocol `qAttached' (query-attached) packet.
3872 set remote read-siginfo-object
3873 show remote read-siginfo-object
3874 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3877 set remote write-siginfo-object
3878 show remote write-siginfo-object
3879 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3882 set remote reverse-continue
3883 show remote reverse-continue
3884 Control use of remote protocol 'bc' (reverse-continue) packet.
3886 set remote reverse-step
3887 show remote reverse-step
3888 Control use of remote protocol 'bs' (reverse-step) packet.
3890 set displaced-stepping
3891 show displaced-stepping
3892 Control displaced stepping mode. Displaced stepping is a way to
3893 single-step over breakpoints without removing them from the debuggee.
3894 Also known as "out-of-line single-stepping".
3897 show debug displaced
3898 Control display of debugging info for displaced stepping.
3900 maint set internal-error
3901 maint show internal-error
3902 Control what GDB does when an internal error is detected.
3904 maint set internal-warning
3905 maint show internal-warning
3906 Control what GDB does when an internal warning is detected.
3911 Use a wrapper program to launch programs for debugging.
3913 set multiple-symbols (all|ask|cancel)
3914 show multiple-symbols
3915 The value of this variable can be changed to adjust the debugger behavior
3916 when an expression or a breakpoint location contains an ambiguous symbol
3917 name (an overloaded function name, for instance).
3919 set breakpoint always-inserted
3920 show breakpoint always-inserted
3921 Keep breakpoints always inserted in the target, as opposed to inserting
3922 them when resuming the target, and removing them when the target stops.
3923 This option can improve debugger performance on slow remote targets.
3925 set arm fallback-mode (arm|thumb|auto)
3926 show arm fallback-mode
3927 set arm force-mode (arm|thumb|auto)
3929 These commands control how ARM GDB determines whether instructions
3930 are ARM or Thumb. The default for both settings is auto, which uses
3931 the current CPSR value for instructions without symbols; previous
3932 versions of GDB behaved as if "set arm fallback-mode arm".
3934 set disable-randomization
3935 show disable-randomization
3936 Standalone programs run with the virtual address space randomization enabled
3937 by default on some platforms. This option keeps the addresses stable across
3938 multiple debugging sessions.
3942 Control whether other threads are stopped or not when some thread hits
3947 Requests that asynchronous execution is enabled in the target, if available.
3948 In this case, it's possible to resume target in the background, and interact
3949 with GDB while the target is running. "show target-async" displays the
3950 current state of asynchronous execution of the target.
3952 set target-wide-charset
3953 show target-wide-charset
3954 The target-wide-charset is the name of the character set that GDB
3955 uses when printing characters whose type is wchar_t.
3957 set tcp auto-retry (on|off)
3959 set tcp connect-timeout
3960 show tcp connect-timeout
3961 These commands allow GDB to retry failed TCP connections to a remote stub
3962 with a specified timeout period; this is useful if the stub is launched
3963 in parallel with GDB but may not be ready to accept connections immediately.
3965 set libthread-db-search-path
3966 show libthread-db-search-path
3967 Control list of directories which GDB will search for appropriate
3970 set schedule-multiple (on|off)
3971 show schedule-multiple
3972 Allow GDB to resume all threads of all processes or only threads of
3973 the current process.
3977 Use more aggressive caching for accesses to the stack. This improves
3978 performance of remote debugging (particularly backtraces) without
3979 affecting correctness.
3981 set interactive-mode (on|off|auto)
3982 show interactive-mode
3983 Control whether GDB runs in interactive mode (on) or not (off).
3984 When in interactive mode, GDB waits for the user to answer all
3985 queries. Otherwise, GDB does not wait and assumes the default
3986 answer. When set to auto (the default), GDB determines which
3987 mode to use based on the stdin settings.
3992 For program forks, this is replaced by the new more generic `info
3993 inferiors' command. To list checkpoints, you can still use the
3994 `info checkpoints' command, which was an alias for the `info forks'
3998 Replaced by the new `inferior' command. To switch between
3999 checkpoints, you can still use the `restart' command, which was an
4000 alias for the `fork' command.
4003 This is removed, since some targets don't have a notion of
4004 processes. To switch between processes, you can still use the
4005 `inferior' command using GDB's own inferior number.
4008 For program forks, this is replaced by the new more generic `kill
4009 inferior' command. To delete a checkpoint, you can still use the
4010 `delete checkpoint' command, which was an alias for the `delete
4014 For program forks, this is replaced by the new more generic `detach
4015 inferior' command. To detach a checkpoint, you can still use the
4016 `detach checkpoint' command, which was an alias for the `detach
4019 * New native configurations
4021 x86/x86_64 Darwin i[34567]86-*-darwin*
4023 x86_64 MinGW x86_64-*-mingw*
4027 Lattice Mico32 lm32-*
4028 x86 DICOS i[34567]86-*-dicos*
4029 x86_64 DICOS x86_64-*-dicos*
4032 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4033 (mingw32ce) debugging.
4039 These commands were actually not implemented on any target.
4041 *** Changes in GDB 6.8
4043 * New native configurations
4045 NetBSD/hppa hppa*-*netbsd*
4046 Xtensa GNU/Linux xtensa*-*-linux*
4050 NetBSD/hppa hppa*-*-netbsd*
4051 Xtensa GNU/Lunux xtensa*-*-linux*
4053 * Change in command line behavior -- corefiles vs. process ids.
4055 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4056 attaching to process NUMBER fails, GDB no longer attempts to open a
4057 core file named NUMBER. Attaching to a program using the -c option
4058 is no longer supported. Instead, use the '-p' or '--pid' options.
4060 * GDB can now be built as a native debugger for debugging Windows x86
4061 (mingw32) Portable Executable (PE) programs.
4063 * Pending breakpoints no longer change their number when their address
4066 * GDB now supports breakpoints with multiple locations,
4067 including breakpoints on C++ constructors, inside C++ templates,
4068 and in inlined functions.
4070 * GDB's ability to debug optimized code has been improved. GDB more
4071 accurately identifies function bodies and lexical blocks that occupy
4072 more than one contiguous range of addresses.
4074 * Target descriptions can now describe registers for PowerPC.
4076 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4077 registers on PowerPC targets.
4079 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4080 targets even when the libthread_db library is not available.
4082 * The GDB remote stub, gdbserver, now supports the new file transfer
4083 commands (remote put, remote get, and remote delete).
4085 * The GDB remote stub, gdbserver, now supports run and attach in
4086 extended-remote mode.
4088 * hppa*64*-*-hpux11* target broken
4089 The debugger is unable to start a program and fails with the following
4090 error: "Error trying to get information about dynamic linker".
4091 The gdb-6.7 release is also affected.
4093 * GDB now supports the --enable-targets= configure option to allow
4094 building a single GDB executable that supports multiple remote
4095 target architectures.
4097 * GDB now supports debugging C and C++ programs which use the
4098 Decimal Floating Point extension. In addition, the PowerPC target
4099 now has a set of pseudo-registers to inspect decimal float values
4100 stored in two consecutive float registers.
4102 * The -break-insert MI command can optionally create pending
4105 * Improved support for debugging Ada
4106 Many improvements to the Ada language support have been made. These
4108 - Better support for Ada2005 interface types
4109 - Improved handling of arrays and slices in general
4110 - Better support for Taft-amendment types
4111 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4113 - Improved command completion in Ada
4116 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4121 set print frame-arguments (all|scalars|none)
4122 show print frame-arguments
4123 The value of this variable can be changed to control which argument
4124 values should be printed by the debugger when displaying a frame.
4129 Transfer files to and from a remote target, and delete remote files.
4136 Transfer files to and from a remote target, and delete remote files.
4138 * New remote packets
4145 Open, close, read, write, and delete files on the remote system.
4148 Attach to an existing process on the remote system, in extended-remote
4152 Run a new process on the remote system, in extended-remote mode.
4154 *** Changes in GDB 6.7
4156 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4157 bfd, libiberty and opcodes, as revealed by static analysis donated by
4158 Coverity, Inc. (http://scan.coverity.com).
4160 * When looking up multiply-defined global symbols, GDB will now prefer the
4161 symbol definition in the current shared library if it was built using the
4162 -Bsymbolic linker option.
4164 * When the Text User Interface (TUI) is not configured, GDB will now
4165 recognize the -tui command-line option and print a message that the TUI
4168 * The GDB remote stub, gdbserver, now has lower overhead for high
4169 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4171 * GDB for MIPS targets now autodetects whether a remote target provides
4172 32-bit or 64-bit register values.
4174 * Support for C++ member pointers has been improved.
4176 * GDB now understands XML target descriptions, which specify the
4177 target's overall architecture. GDB can read a description from
4178 a local file or over the remote serial protocol.
4180 * Vectors of single-byte data use a new integer type which is not
4181 automatically displayed as character or string data.
4183 * The /s format now works with the print command. It displays
4184 arrays of single-byte integers and pointers to single-byte integers
4187 * Target descriptions can now describe target-specific registers,
4188 for architectures which have implemented the support (currently
4189 only ARM, M68K, and MIPS).
4191 * GDB and the GDB remote stub, gdbserver, now support the XScale
4194 * The GDB remote stub, gdbserver, has been updated to support
4195 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4196 has been rewritten to use the standard GDB remote protocol.
4198 * GDB can now step into C++ functions which are called through thunks.
4200 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4202 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4203 layout. It also supports a TextSeg= and DataSeg= response when only
4204 segment base addresses (rather than offsets) are available.
4206 * The /i format now outputs any trailing branch delay slot instructions
4207 immediately following the last instruction within the count specified.
4209 * The GDB remote protocol "T" stop reply packet now supports a
4210 "library" response. Combined with the new "qXfer:libraries:read"
4211 packet, this response allows GDB to debug shared libraries on targets
4212 where the operating system manages the list of loaded libraries (e.g.
4213 Windows and SymbianOS).
4215 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4216 (DLLs) on Windows and Windows CE targets.
4218 * GDB now supports a faster verification that a .debug file matches its binary
4219 according to its build-id signature, if the signature is present.
4225 Enable or disable hardware flow control (RTS/CTS) on the serial port
4226 when debugging using remote targets.
4228 set mem inaccessible-by-default
4229 show mem inaccessible-by-default
4230 If the target supplies a memory map, for instance via the remote
4231 protocol's "qXfer:memory-map:read" packet, setting this variable
4232 prevents GDB from accessing memory outside the memory map. This
4233 is useful for targets with memory mapped registers or which react
4234 badly to accesses of unmapped address space.
4236 set breakpoint auto-hw
4237 show breakpoint auto-hw
4238 If the target supplies a memory map, for instance via the remote
4239 protocol's "qXfer:memory-map:read" packet, setting this variable
4240 lets GDB use hardware breakpoints automatically for memory regions
4241 where it can not use software breakpoints. This covers both the
4242 "break" command and internal breakpoints used for other commands
4243 including "next" and "finish".
4246 catch exception unhandled
4247 Stop the program execution when Ada exceptions are raised.
4250 Stop the program execution when an Ada assertion failed.
4254 Set an alternate system root for target files. This is a more
4255 general version of "set solib-absolute-prefix", which is now
4256 an alias to "set sysroot".
4259 Provide extended SPU facility status information. This set of
4260 commands is available only when debugging the Cell/B.E. SPU
4263 * New native configurations
4265 OpenBSD/sh sh*-*openbsd*
4268 unset tdesc filename
4270 Use the specified local file as an XML target description, and do
4271 not query the target for its built-in description.
4275 OpenBSD/sh sh*-*-openbsd*
4276 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4277 Toshiba Media Processor mep-elf
4279 * New remote packets
4282 Ignore the specified signals; pass them directly to the debugged program
4283 without stopping other threads or reporting them to GDB.
4285 qXfer:features:read:
4286 Read an XML target description from the target, which describes its
4291 Read or write contents of an spufs file on the target system. These
4292 packets are available only on the Cell/B.E. SPU architecture.
4294 qXfer:libraries:read:
4295 Report the loaded shared libraries. Combined with new "T" packet
4296 response, this packet allows GDB to debug shared libraries on
4297 targets where the operating system manages the list of loaded
4298 libraries (e.g. Windows and SymbianOS).
4302 Support for these obsolete configurations has been removed.
4310 i[34567]86-*-lynxos*
4311 i[34567]86-*-netware*
4312 i[34567]86-*-sco3.2v5*
4313 i[34567]86-*-sco3.2v4*
4315 i[34567]86-*-sysv4.2*
4318 i[34567]86-*-unixware2*
4319 i[34567]86-*-unixware*
4328 * Other removed features
4335 Various m68k-only ROM monitors.
4342 Various Renesas ROM monitors and debugging interfaces for SH and
4347 Support for a Macraigor serial interface to on-chip debugging.
4348 GDB does not directly support the newer parallel or USB
4353 A debug information format. The predecessor to DWARF 2 and
4354 DWARF 3, which are still supported.
4356 Support for the HP aCC compiler on HP-UX/PA-RISC
4358 SOM-encapsulated symbolic debugging information, automatic
4359 invocation of pxdb, and the aCC custom C++ ABI. This does not
4360 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4361 with aCC can still be debugged on an assembly level.
4363 MIPS ".pdr" sections
4365 A MIPS-specific format used to describe stack frame layout
4366 in debugging information.
4370 GDB could work with an older version of Guile to debug
4371 the interpreter and Scheme programs running in it.
4373 set mips stack-arg-size
4374 set mips saved-gpreg-size
4376 Use "set mips abi" to control parameter passing for MIPS.
4378 *** Changes in GDB 6.6
4383 Cell Broadband Engine SPU spu-elf
4385 * GDB can now be configured as a cross-debugger targeting native Windows
4386 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4387 running on a Windows system over TCP/IP to debug Windows programs.
4389 * The GDB remote stub, gdbserver, has been updated to support Windows and
4390 Cygwin debugging. Both single-threaded and multi-threaded programs are
4393 * The "set trust-readonly-sections" command works again. This command was
4394 broken in GDB 6.3, 6.4, and 6.5.
4396 * The "load" command now supports writing to flash memory, if the remote
4397 stub provides the required support.
4399 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4400 longer requires symbolic debug information (e.g. DWARF-2).
4405 unset substitute-path
4406 show substitute-path
4407 Manage a list of substitution rules that GDB uses to rewrite the name
4408 of the directories where the sources are located. This can be useful
4409 for instance when the sources were moved to a different location
4410 between compilation and debugging.
4414 Print each CLI command as it is executed. Each command is prefixed with
4415 a number of `+' symbols representing the nesting depth.
4416 The source command now has a `-v' option to enable the same feature.
4420 The ARM Demon monitor support (RDP protocol, "target rdp").
4422 Kernel Object Display, an embedded debugging feature which only worked with
4423 an obsolete version of Cisco IOS.
4425 The 'set download-write-size' and 'show download-write-size' commands.
4427 * New remote packets
4430 Tell a stub about GDB client features, and request remote target features.
4431 The first feature implemented is PacketSize, which allows the target to
4432 specify the size of packets it can handle - to minimize the number of
4433 packets required and improve performance when connected to a remote
4437 Fetch an OS auxilliary vector from the remote stub. This packet is a
4438 more efficient replacement for qPart:auxv:read.
4440 qXfer:memory-map:read:
4441 Fetch a memory map from the remote stub, including information about
4442 RAM, ROM, and flash memory devices.
4447 Erase and program a flash memory device.
4449 * Removed remote packets
4452 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4453 used it, and only gdbserver implemented it.
4455 *** Changes in GDB 6.5
4459 Renesas M32C/M16C m32c-elf
4461 Morpho Technologies ms1 ms1-elf
4465 init-if-undefined Initialize a convenience variable, but
4466 only if it doesn't already have a value.
4468 The following commands are presently only implemented for native GNU/Linux:
4470 checkpoint Save a snapshot of the program state.
4472 restart <n> Return the program state to a
4473 previously saved state.
4475 info checkpoints List currently saved checkpoints.
4477 delete-checkpoint <n> Delete a previously saved checkpoint.
4479 set|show detach-on-fork Tell gdb whether to detach from a newly
4480 forked process, or to keep debugging it.
4482 info forks List forks of the user program that
4483 are available to be debugged.
4485 fork <n> Switch to debugging one of several
4486 forks of the user program that are
4487 available to be debugged.
4489 delete-fork <n> Delete a fork from the list of forks
4490 that are available to be debugged (and
4491 kill the forked process).
4493 detach-fork <n> Delete a fork from the list of forks
4494 that are available to be debugged (and
4495 allow the process to continue).
4499 Morpho Technologies ms2 ms1-elf
4501 * Improved Windows host support
4503 GDB now builds as a cross debugger hosted on i686-mingw32, including
4504 native console support, and remote communications using either
4505 network sockets or serial ports.
4507 * Improved Modula-2 language support
4509 GDB can now print most types in the Modula-2 syntax. This includes:
4510 basic types, set types, record types, enumerated types, range types,
4511 pointer types and ARRAY types. Procedure var parameters are correctly
4512 printed and hexadecimal addresses and character constants are also
4513 written in the Modula-2 syntax. Best results can be obtained by using
4514 GNU Modula-2 together with the -gdwarf-2 command line option.
4518 The ARM rdi-share module.
4520 The Netware NLM debug server.
4522 *** Changes in GDB 6.4
4524 * New native configurations
4526 OpenBSD/arm arm*-*-openbsd*
4527 OpenBSD/mips64 mips64-*-openbsd*
4531 Morpho Technologies ms1 ms1-elf
4533 * New command line options
4535 --batch-silent As for --batch, but totally silent.
4536 --return-child-result The debugger will exist with the same value
4537 the child (debugged) program exited with.
4538 --eval-command COMMAND, -ex COMMAND
4539 Execute a single GDB CLI command. This may be
4540 specified multiple times and in conjunction
4541 with the --command (-x) option.
4543 * Deprecated commands removed
4545 The following commands, that were deprecated in 2000, have been
4549 set|show arm disassembly-flavor set|show arm disassembler
4550 othernames set arm disassembler
4551 set|show remotedebug set|show debug remote
4552 set|show archdebug set|show debug arch
4553 set|show eventdebug set|show debug event
4556 * New BSD user-level threads support
4558 It is now possible to debug programs using the user-level threads
4559 library on OpenBSD and FreeBSD. Currently supported (target)
4562 FreeBSD/amd64 x86_64-*-freebsd*
4563 FreeBSD/i386 i386-*-freebsd*
4564 OpenBSD/i386 i386-*-openbsd*
4566 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4567 are not yet supported.
4569 * New support for Matsushita MN10300 w/sim added
4570 (Work in progress). mn10300-elf.
4572 * REMOVED configurations and files
4574 VxWorks and the XDR protocol *-*-vxworks
4575 Motorola MCORE mcore-*-*
4576 National Semiconductor NS32000 ns32k-*-*
4578 * New "set print array-indexes" command
4580 After turning this setting "on", GDB prints the index of each element
4581 when displaying arrays. The default is "off" to preserve the previous
4584 * VAX floating point support
4586 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4588 * User-defined command support
4590 In addition to using $arg0..$arg9 for argument passing, it is now possible
4591 to use $argc to determine now many arguments have been passed. See the
4592 section on user-defined commands in the user manual for more information.
4594 *** Changes in GDB 6.3:
4596 * New command line option
4598 GDB now accepts -l followed by a number to set the timeout for remote
4601 * GDB works with GCC -feliminate-dwarf2-dups
4603 GDB now supports a more compact representation of DWARF-2 debug
4604 information using DW_FORM_ref_addr references. These are produced
4605 by GCC with the option -feliminate-dwarf2-dups and also by some
4606 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4607 to use -feliminate-dwarf2-dups.
4609 * Internationalization
4611 When supported by the host system, GDB will be built with
4612 internationalization (libintl). The task of marking up the sources is
4613 continued, we're looking forward to our first translation.
4617 Initial support for debugging programs compiled with the GNAT
4618 implementation of the Ada programming language has been integrated
4619 into GDB. In this release, support is limited to expression evaluation.
4621 * New native configurations
4623 GNU/Linux/m32r m32r-*-linux-gnu
4627 GDB's remote protocol now includes support for the 'p' packet. This
4628 packet is used to fetch individual registers from a remote inferior.
4630 * END-OF-LIFE registers[] compatibility module
4632 GDB's internal register infrastructure has been completely rewritten.
4633 The new infrastructure making possible the implementation of key new
4634 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4637 GDB 6.3 will be the last release to include the the registers[]
4638 compatibility module that allowed out-of-date configurations to
4639 continue to work. This change directly impacts the following
4649 powerpc bdm protocol
4651 Unless there is activity to revive these configurations, they will be
4652 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4654 * OBSOLETE configurations and files
4656 Configurations that have been declared obsolete in this release have
4657 been commented out. Unless there is activity to revive these
4658 configurations, the next release of GDB will have their sources
4659 permanently REMOVED.
4668 *** Changes in GDB 6.2.1:
4670 * MIPS `break main; run' gave an heuristic-fence-post warning
4672 When attempting to run even a simple program, a warning about
4673 heuristic-fence-post being hit would be reported. This problem has
4676 * MIPS IRIX 'long double' crashed GDB
4678 When examining a long double variable, GDB would get a segmentation
4679 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4680 IRIX long double values).
4684 A bug in the VAX stack code was causing problems with the "next"
4685 command. This problem has been fixed.
4687 *** Changes in GDB 6.2:
4689 * Fix for ``many threads''
4691 On GNU/Linux systems that use the NPTL threads library, a program
4692 rapidly creating and deleting threads would confuse GDB leading to the
4695 ptrace: No such process.
4696 thread_db_get_info: cannot get thread info: generic error
4698 This problem has been fixed.
4700 * "-async" and "-noasync" options removed.
4702 Support for the broken "-noasync" option has been removed (it caused
4705 * New ``start'' command.
4707 This command runs the program until the begining of the main procedure.
4709 * New BSD Kernel Data Access Library (libkvm) interface
4711 Using ``target kvm'' it is now possible to debug kernel core dumps and
4712 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4713 platforms. Currently supported (native-only) configurations are:
4715 FreeBSD/amd64 x86_64-*-freebsd*
4716 FreeBSD/i386 i?86-*-freebsd*
4717 NetBSD/i386 i?86-*-netbsd*
4718 NetBSD/m68k m68*-*-netbsd*
4719 NetBSD/sparc sparc-*-netbsd*
4720 OpenBSD/amd64 x86_64-*-openbsd*
4721 OpenBSD/i386 i?86-*-openbsd*
4722 OpenBSD/m68k m68*-openbsd*
4723 OpenBSD/sparc sparc-*-openbsd*
4725 * Signal trampoline code overhauled
4727 Many generic problems with GDB's signal handling code have been fixed.
4728 These include: backtraces through non-contiguous stacks; recognition
4729 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4730 call; backtrace through a signal trampoline; step into and out of
4731 signal handlers; and single-stepping in the signal trampoline.
4733 Please note that kernel bugs are a limiting factor here. These
4734 features have been shown to work on an s390 GNU/Linux system that
4735 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4737 * Cygwin support for DWARF 2 added.
4739 * New native configurations
4741 GNU/Linux/hppa hppa*-*-linux*
4742 OpenBSD/hppa hppa*-*-openbsd*
4743 OpenBSD/m68k m68*-*-openbsd*
4744 OpenBSD/m88k m88*-*-openbsd*
4745 OpenBSD/powerpc powerpc-*-openbsd*
4746 NetBSD/vax vax-*-netbsd*
4747 OpenBSD/vax vax-*-openbsd*
4749 * END-OF-LIFE frame compatibility module
4751 GDB's internal frame infrastructure has been completely rewritten.
4752 The new infrastructure making it possible to support key new features
4753 including DWARF 2 Call Frame Information. To aid in the task of
4754 migrating old configurations to this new infrastructure, a
4755 compatibility module, that allowed old configurations to continue to
4756 work, was also included.
4758 GDB 6.2 will be the last release to include this frame compatibility
4759 module. This change directly impacts the following configurations:
4769 Unless there is activity to revive these configurations, they will be
4770 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4772 * REMOVED configurations and files
4774 Sun 3, running SunOS 3 m68*-*-sunos3*
4775 Sun 3, running SunOS 4 m68*-*-sunos4*
4776 Sun 2, running SunOS 3 m68000-*-sunos3*
4777 Sun 2, running SunOS 4 m68000-*-sunos4*
4778 Motorola 680x0 running LynxOS m68*-*-lynxos*
4779 AT&T 3b1/Unix pc m68*-att-*
4780 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4781 decstation mips-dec-* mips-little-*
4782 riscos mips-*-riscos* mips-*-sysv*
4783 sonymips mips-sony-*
4784 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4786 *** Changes in GDB 6.1.1:
4788 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4790 The TUI (Text-mode User Interface) is now built as part of a default
4791 GDB configuration. It is enabled by either selecting the TUI with the
4792 command line option "-i=tui" or by running the separate "gdbtui"
4793 program. For more information on the TUI, see the manual "Debugging
4796 * Pending breakpoint support (also included in GDB 6.1)
4798 Support has been added to allow you to specify breakpoints in shared
4799 libraries that have not yet been loaded. If a breakpoint location
4800 cannot be found, and the "breakpoint pending" option is set to auto,
4801 GDB queries you if you wish to make the breakpoint pending on a future
4802 shared-library load. If and when GDB resolves the breakpoint symbol,
4803 the pending breakpoint is removed as one or more regular breakpoints
4806 Pending breakpoints are very useful for GCJ Java debugging.
4808 * Fixed ISO-C build problems
4810 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4811 non ISO-C code that stopped them being built using a more strict ISO-C
4812 compiler (e.g., IBM's C compiler).
4814 * Fixed build problem on IRIX 5
4816 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4817 wasn't able to compile compile on an IRIX 5 system.
4819 * Added execute permission to gdb/gdbserver/configure
4821 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4822 permission. This bug would cause configure to fail on a number of
4823 systems (Solaris, IRIX). Ref: server/519.
4825 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4827 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4828 has been updated to use constant array sizes.
4830 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4832 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4833 its generated DWARF Call Frame Info. This encoding was causing GDB to
4834 panic, that panic has been fixed. Ref: gdb/1628.
4836 * Fixed a problem when examining parameters in shared library code.
4838 When examining parameters in optimized shared library code generated
4839 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4840 not available''. GDB now correctly displays the variable's value.
4842 *** Changes in GDB 6.1:
4844 * Removed --with-mmalloc
4846 Support for the mmalloc memory manager has been removed, as it
4847 conflicted with the internal gdb byte cache.
4849 * Changes in AMD64 configurations
4851 The AMD64 target now includes the %cs and %ss registers. As a result
4852 the AMD64 remote protocol has changed; this affects the floating-point
4853 and SSE registers. If you rely on those registers for your debugging,
4854 you should upgrade gdbserver on the remote side.
4856 * Revised SPARC target
4858 The SPARC target has been completely revised, incorporating the
4859 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4860 support for LynxOS and SunOS 4 has been dropped. Calling functions
4861 from within GDB on operating systems with a non-executable stack
4862 (Solaris, OpenBSD) now works.
4866 GDB has a new C++ demangler which does a better job on the mangled
4867 names generated by current versions of g++. It also runs faster, so
4868 with this and other changes gdb should now start faster on large C++
4871 * DWARF 2 Location Expressions
4873 GDB support for location expressions has been extended to support function
4874 arguments and frame bases. Older versions of GDB could crash when they
4877 * C++ nested types and namespaces
4879 GDB's support for nested types and namespaces in C++ has been
4880 improved, especially if you use the DWARF 2 debugging format. (This
4881 is the default for recent versions of GCC on most platforms.)
4882 Specifically, if you have a class "Inner" defined within a class or
4883 namespace "Outer", then GDB realizes that the class's name is
4884 "Outer::Inner", not simply "Inner". This should greatly reduce the
4885 frequency of complaints about not finding RTTI symbols. In addition,
4886 if you are stopped at inside of a function defined within a namespace,
4887 GDB modifies its name lookup accordingly.
4889 * New native configurations
4891 NetBSD/amd64 x86_64-*-netbsd*
4892 OpenBSD/amd64 x86_64-*-openbsd*
4893 OpenBSD/alpha alpha*-*-openbsd*
4894 OpenBSD/sparc sparc-*-openbsd*
4895 OpenBSD/sparc64 sparc64-*-openbsd*
4897 * New debugging protocols
4899 M32R with SDI protocol m32r-*-elf*
4901 * "set prompt-escape-char" command deleted.
4903 The command "set prompt-escape-char" has been deleted. This command,
4904 and its very obscure effet on GDB's prompt, was never documented,
4905 tested, nor mentioned in the NEWS file.
4907 * OBSOLETE configurations and files
4909 Configurations that have been declared obsolete in this release have
4910 been commented out. Unless there is activity to revive these
4911 configurations, the next release of GDB will have their sources
4912 permanently REMOVED.
4914 Sun 3, running SunOS 3 m68*-*-sunos3*
4915 Sun 3, running SunOS 4 m68*-*-sunos4*
4916 Sun 2, running SunOS 3 m68000-*-sunos3*
4917 Sun 2, running SunOS 4 m68000-*-sunos4*
4918 Motorola 680x0 running LynxOS m68*-*-lynxos*
4919 AT&T 3b1/Unix pc m68*-att-*
4920 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4921 decstation mips-dec-* mips-little-*
4922 riscos mips-*-riscos* mips-*-sysv*
4923 sonymips mips-sony-*
4924 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4926 * REMOVED configurations and files
4928 SGI Irix-4.x mips-sgi-irix4 or iris4
4929 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4930 Z8000 simulator z8k-zilog-none or z8ksim
4931 Matsushita MN10200 w/simulator mn10200-*-*
4932 H8/500 simulator h8500-hitachi-hms or h8500hms
4933 HP/PA running BSD hppa*-*-bsd*
4934 HP/PA running OSF/1 hppa*-*-osf*
4935 HP/PA Pro target hppa*-*-pro*
4936 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4937 386BSD i[3456]86-*-bsd*
4938 Sequent family i[3456]86-sequent-sysv4*
4939 i[3456]86-sequent-sysv*
4940 i[3456]86-sequent-bsd*
4941 SPARC running LynxOS sparc-*-lynxos*
4942 SPARC running SunOS 4 sparc-*-sunos4*
4943 Tsqware Sparclet sparclet-*-*
4944 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4946 *** Changes in GDB 6.0:
4950 Support for debugging the Objective-C programming language has been
4951 integrated into GDB.
4953 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4955 DWARF 2's Call Frame Information makes available compiler generated
4956 information that more exactly describes the program's run-time stack.
4957 By using this information, GDB is able to provide more robust stack
4960 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4961 have been updated to use a new backtrace mechanism which includes
4962 DWARF 2 CFI support.
4966 GDB's remote protocol has been extended to include support for hosted
4967 file I/O (where the remote target uses GDB's file system). See GDB's
4968 remote protocol documentation for details.
4970 * All targets using the new architecture framework.
4972 All of GDB's targets have been updated to use the new internal
4973 architecture framework. The way is now open for future GDB releases
4974 to include cross-architecture native debugging support (i386 on amd64,
4977 * GNU/Linux's Thread Local Storage (TLS)
4979 GDB now includes support for for the GNU/Linux implementation of
4980 per-thread variables.
4982 * GNU/Linux's Native POSIX Thread Library (NPTL)
4984 GDB's thread code has been updated to work with either the new
4985 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4987 * Separate debug info.
4989 GDB, in conjunction with BINUTILS, now supports a mechanism for
4990 automatically loading debug information from a separate file. Instead
4991 of shipping full debug and non-debug versions of system libraries,
4992 system integrators can now instead ship just the stripped libraries
4993 and optional debug files.
4995 * DWARF 2 Location Expressions
4997 DWARF 2 Location Expressions allow the compiler to more completely
4998 describe the location of variables (even in optimized code) to the
5001 GDB now includes preliminary support for location expressions (support
5002 for DW_OP_piece is still missing).
5006 A number of long standing bugs that caused GDB to die while starting a
5007 Java application have been fixed. GDB's Java support is now
5008 considered "useable".
5010 * GNU/Linux support for fork, vfork, and exec.
5012 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5013 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5016 * GDB supports logging output to a file
5018 There are two new commands, "set logging" and "show logging", which can be
5019 used to capture GDB's output to a file.
5021 * The meaning of "detach" has changed for gdbserver
5023 The "detach" command will now resume the application, as documented. To
5024 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5027 * d10v, m68hc11 `regs' command deprecated
5029 The `info registers' command has been updated so that it displays the
5030 registers using a format identical to the old `regs' command.
5034 A new command, "maint set profile on/off", has been added. This command can
5035 be used to enable or disable profiling while running GDB, to profile a
5036 session or a set of commands. In addition there is a new configure switch,
5037 "--enable-profiling", which will cause GDB to be compiled with profiling
5038 data, for more informative profiling results.
5040 * Default MI syntax changed to "mi2".
5042 The default MI (machine interface) syntax, enabled by the command line
5043 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5044 "mi1", can be enabled by specifying the option "-i=mi1".
5046 Support for the original "mi0" syntax (included in GDB 5.0) has been
5049 Fix for gdb/192: removed extraneous space when displaying frame level.
5050 Fix for gdb/672: update changelist is now output in mi list format.
5051 Fix for gdb/702: a -var-assign that updates the value now shows up
5052 in a subsequent -var-update.
5054 * New native configurations.
5056 FreeBSD/amd64 x86_64-*-freebsd*
5058 * Multi-arched targets.
5060 HP/PA HPUX11 hppa*-*-hpux*
5061 Renesas M32R/D w/simulator m32r-*-elf*
5063 * OBSOLETE configurations and files
5065 Configurations that have been declared obsolete in this release have
5066 been commented out. Unless there is activity to revive these
5067 configurations, the next release of GDB will have their sources
5068 permanently REMOVED.
5070 Z8000 simulator z8k-zilog-none or z8ksim
5071 Matsushita MN10200 w/simulator mn10200-*-*
5072 H8/500 simulator h8500-hitachi-hms or h8500hms
5073 HP/PA running BSD hppa*-*-bsd*
5074 HP/PA running OSF/1 hppa*-*-osf*
5075 HP/PA Pro target hppa*-*-pro*
5076 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5077 Sequent family i[3456]86-sequent-sysv4*
5078 i[3456]86-sequent-sysv*
5079 i[3456]86-sequent-bsd*
5080 Tsqware Sparclet sparclet-*-*
5081 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5083 * REMOVED configurations and files
5086 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5087 IBM AIX PS/2 i[3456]86-*-aix
5088 i386 running Mach 3.0 i[3456]86-*-mach3*
5089 i386 running Mach i[3456]86-*-mach*
5090 i386 running OSF/1 i[3456]86-*osf1mk*
5091 HP/Apollo 68k Family m68*-apollo*-sysv*,
5093 m68*-hp-bsd*, m68*-hp-hpux*
5094 Argonaut Risc Chip (ARC) arc-*-*
5095 Mitsubishi D30V d30v-*-*
5096 Fujitsu FR30 fr30-*-elf*
5097 OS/9000 i[34]86-*-os9k
5098 I960 with MON960 i960-*-coff
5100 * MIPS $fp behavior changed
5102 The convenience variable $fp, for the MIPS, now consistently returns
5103 the address of the current frame's base. Previously, depending on the
5104 context, $fp could refer to either $sp or the current frame's base
5105 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5106 The GNU Source-Level Debugger''.
5108 *** Changes in GDB 5.3:
5110 * GNU/Linux shared library multi-threaded performance improved.
5112 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5113 `/proc', in preference to `ptrace' for memory reads. This may result
5114 in an improvement in the start-up time of multi-threaded, shared
5115 library applications when run under GDB. One GDB user writes: ``loads
5116 shared libs like mad''.
5118 * ``gdbserver'' now supports multi-threaded applications on some targets
5120 Support for debugging multi-threaded applications which use
5121 the GNU/Linux LinuxThreads package has been added for
5122 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5123 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5125 * GDB now supports C/C++ preprocessor macros.
5127 GDB now expands preprocessor macro invocations in C/C++ expressions,
5128 and provides various commands for showing macro definitions and how
5131 The new command `macro expand EXPRESSION' expands any macro
5132 invocations in expression, and shows the result.
5134 The new command `show macro MACRO-NAME' shows the definition of the
5135 macro named MACRO-NAME, and where it was defined.
5137 Most compilers don't include information about macros in the debugging
5138 information by default. In GCC 3.1, for example, you need to compile
5139 your program with the options `-gdwarf-2 -g3'. If the macro
5140 information is present in the executable, GDB will read it.
5142 * Multi-arched targets.
5144 DEC Alpha (partial) alpha*-*-*
5145 DEC VAX (partial) vax-*-*
5147 National Semiconductor NS32000 (partial) ns32k-*-*
5148 Motorola 68000 (partial) m68k-*-*
5149 Motorola MCORE mcore-*-*
5153 Fujitsu FRV architecture added by Red Hat frv*-*-*
5156 * New native configurations
5158 Alpha NetBSD alpha*-*-netbsd*
5159 SH NetBSD sh*-*-netbsdelf*
5160 MIPS NetBSD mips*-*-netbsd*
5161 UltraSPARC NetBSD sparc64-*-netbsd*
5163 * OBSOLETE configurations and files
5165 Configurations that have been declared obsolete in this release have
5166 been commented out. Unless there is activity to revive these
5167 configurations, the next release of GDB will have their sources
5168 permanently REMOVED.
5170 Mitsubishi D30V d30v-*-*
5171 OS/9000 i[34]86-*-os9k
5172 IBM AIX PS/2 i[3456]86-*-aix
5173 Fujitsu FR30 fr30-*-elf*
5174 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5175 Argonaut Risc Chip (ARC) arc-*-*
5176 i386 running Mach 3.0 i[3456]86-*-mach3*
5177 i386 running Mach i[3456]86-*-mach*
5178 i386 running OSF/1 i[3456]86-*osf1mk*
5179 HP/Apollo 68k Family m68*-apollo*-sysv*,
5181 m68*-hp-bsd*, m68*-hp-hpux*
5182 I960 with MON960 i960-*-coff
5184 * OBSOLETE languages
5186 CHILL, a Pascal like language used by telecommunications companies.
5188 * REMOVED configurations and files
5190 AMD 29k family via UDI a29k-amd-udi, udi29k
5191 A29K VxWorks a29k-*-vxworks
5192 AMD 29000 embedded, using EBMON a29k-none-none
5193 AMD 29000 embedded with COFF a29k-none-coff
5194 AMD 29000 embedded with a.out a29k-none-aout
5196 testsuite/gdb.hp/gdb.threads-hp/ directory
5198 * New command "set max-user-call-depth <nnn>"
5200 This command allows the user to limit the call depth of user-defined
5201 commands. The default is 1024.
5203 * Changes in FreeBSD/i386 native debugging.
5205 Support for the "generate-core-file" has been added.
5207 * New commands "dump", "append", and "restore".
5209 These commands allow data to be copied from target memory
5210 to a bfd-format or binary file (dump and append), and back
5211 from a file into memory (restore).
5213 * Improved "next/step" support on multi-processor Alpha Tru64.
5215 The previous single-step mechanism could cause unpredictable problems,
5216 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5217 of a software single-step mechanism prevents this.
5219 *** Changes in GDB 5.2.1:
5227 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5228 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5229 Fix, by Joel Brobecker imported from mainline.
5231 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5232 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5233 Fix, by Fred Fish, imported from mainline.
5235 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5236 Surprisingly enough, it works now.
5237 By Michal Ludvig, imported from mainline.
5239 i386 hardware watchpoint support:
5240 avoid misses on second run for some targets.
5241 By Pierre Muller, imported from mainline.
5243 *** Changes in GDB 5.2:
5245 * New command "set trust-readonly-sections on[off]".
5247 This command is a hint that tells gdb that read-only sections
5248 really are read-only (ie. that their contents will not change).
5249 In this mode, gdb will go to the object file rather than the
5250 target to read memory from read-only sections (such as ".text").
5251 This can be a significant performance improvement on some
5252 (notably embedded) targets.
5254 * New command "generate-core-file" (or "gcore").
5256 This new gdb command allows the user to drop a core file of the child
5257 process state at any time. So far it's been implemented only for
5258 GNU/Linux and Solaris, but should be relatively easily ported to other
5259 hosts. Argument is core file name (defaults to core.<pid>).
5261 * New command line option
5263 GDB now accepts --pid or -p followed by a process id.
5265 * Change in command line behavior -- corefiles vs. process ids.
5267 There is a subtle behavior in the way in which GDB handles
5268 command line arguments. The first non-flag argument is always
5269 a program to debug, but the second non-flag argument may either
5270 be a corefile or a process id. Previously, GDB would attempt to
5271 open the second argument as a corefile, and if that failed, would
5272 issue a superfluous error message and then attempt to attach it as
5273 a process. Now, if the second argument begins with a non-digit,
5274 it will be treated as a corefile. If it begins with a digit,
5275 GDB will attempt to attach it as a process, and if no such process
5276 is found, will then attempt to open it as a corefile.
5278 * Changes in ARM configurations.
5280 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5281 configuration is fully multi-arch.
5283 * New native configurations
5285 ARM NetBSD arm*-*-netbsd*
5286 x86 OpenBSD i[3456]86-*-openbsd*
5287 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5288 Sparc64 running FreeBSD sparc64-*-freebsd*
5292 Sanyo XStormy16 xstormy16-elf
5294 * OBSOLETE configurations and files
5296 Configurations that have been declared obsolete in this release have
5297 been commented out. Unless there is activity to revive these
5298 configurations, the next release of GDB will have their sources
5299 permanently REMOVED.
5301 AMD 29k family via UDI a29k-amd-udi, udi29k
5302 A29K VxWorks a29k-*-vxworks
5303 AMD 29000 embedded, using EBMON a29k-none-none
5304 AMD 29000 embedded with COFF a29k-none-coff
5305 AMD 29000 embedded with a.out a29k-none-aout
5307 testsuite/gdb.hp/gdb.threads-hp/ directory
5309 * REMOVED configurations and files
5311 TI TMS320C80 tic80-*-*
5313 PowerPC Solaris powerpcle-*-solaris*
5314 PowerPC Windows NT powerpcle-*-cygwin32
5315 PowerPC Netware powerpc-*-netware*
5316 Harris/CXUX m88k m88*-harris-cxux*
5317 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5318 ns32k-utek-sysv* ns32k-utek-*
5319 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5320 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5321 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5322 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5323 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5325 * Changes to command line processing
5327 The new `--args' feature can be used to specify command-line arguments
5328 for the inferior from gdb's command line.
5330 * Changes to key bindings
5332 There is a new `operate-and-get-next' function bound to `C-o'.
5334 *** Changes in GDB 5.1.1
5336 Fix compile problem on DJGPP.
5338 Fix a problem with floating-point registers on the i386 being
5341 Fix to stop GDB crashing on .debug_str debug info.
5343 Numerous documentation fixes.
5345 Numerous testsuite fixes.
5347 *** Changes in GDB 5.1:
5349 * New native configurations
5351 Alpha FreeBSD alpha*-*-freebsd*
5352 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5353 MIPS GNU/Linux mips*-*-linux*
5354 MIPS SGI Irix 6.x mips*-sgi-irix6*
5355 ia64 AIX ia64-*-aix*
5356 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5360 Motorola 68HC11 and 68HC12 m68hc11-elf
5362 UltraSparc running GNU/Linux sparc64-*-linux*
5364 * OBSOLETE configurations and files
5366 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5367 Harris/CXUX m88k m88*-harris-cxux*
5368 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5369 ns32k-utek-sysv* ns32k-utek-*
5370 TI TMS320C80 tic80-*-*
5372 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5373 PowerPC Solaris powerpcle-*-solaris*
5374 PowerPC Windows NT powerpcle-*-cygwin32
5375 PowerPC Netware powerpc-*-netware*
5376 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5377 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5378 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5379 Apple Macintosh (MPW) host N/A
5381 stuff.c (Program to stuff files into a specially prepared space in kdb)
5382 kdb-start.c (Main loop for the standalone kernel debugger)
5384 Configurations that have been declared obsolete in this release have
5385 been commented out. Unless there is activity to revive these
5386 configurations, the next release of GDB will have their sources
5387 permanently REMOVED.
5389 * REMOVED configurations and files
5391 Altos 3068 m68*-altos-*
5392 Convex c1-*-*, c2-*-*
5394 ARM RISCix arm-*-* (as host)
5398 * GDB has been converted to ISO C.
5400 GDB's source code has been converted to ISO C. In particular, the
5401 sources are fully protoized, and rely on standard headers being
5406 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5408 * The MI enabled by default.
5410 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5411 revised and enabled by default. Packages which use GDB as a debugging
5412 engine behind a UI or another front end are encouraged to switch to
5413 using the GDB/MI interface, instead of the old annotations interface
5414 which is now deprecated.
5416 * Support for debugging Pascal programs.
5418 GDB now includes support for debugging Pascal programs. The following
5419 main features are supported:
5421 - Pascal-specific data types such as sets;
5423 - automatic recognition of Pascal sources based on file-name
5426 - Pascal-style display of data types, variables, and functions;
5428 - a Pascal expression parser.
5430 However, some important features are not yet supported.
5432 - Pascal string operations are not supported at all;
5434 - there are some problems with boolean types;
5436 - Pascal type hexadecimal constants are not supported
5437 because they conflict with the internal variables format;
5439 - support for Pascal objects and classes is not full yet;
5441 - unlike Pascal, GDB is case-sensitive for symbol names.
5443 * Changes in completion.
5445 Commands such as `shell', `run' and `set args', which pass arguments
5446 to inferior programs, now complete on file names, similar to what
5447 users expect at the shell prompt.
5449 Commands which accept locations, such as `disassemble', `print',
5450 `breakpoint', `until', etc. now complete on filenames as well as
5451 program symbols. Thus, if you type "break foob TAB", and the source
5452 files linked into the programs include `foobar.c', that file name will
5453 be one of the candidates for completion. However, file names are not
5454 considered for completion after you typed a colon that delimits a file
5455 name from a name of a function in that file, as in "break foo.c:bar".
5457 `set demangle-style' completes on available demangling styles.
5459 * New platform-independent commands:
5461 It is now possible to define a post-hook for a command as well as a
5462 hook that runs before the command. For more details, see the
5463 documentation of `hookpost' in the GDB manual.
5465 * Changes in GNU/Linux native debugging.
5467 Support for debugging multi-threaded programs has been completely
5468 revised for all platforms except m68k and sparc. You can now debug as
5469 many threads as your system allows you to have.
5471 Attach/detach is supported for multi-threaded programs.
5473 Support for SSE registers was added for x86. This doesn't work for
5474 multi-threaded programs though.
5476 * Changes in MIPS configurations.
5478 Multi-arch support is enabled for all MIPS configurations.
5480 GDB can now be built as native debugger on SGI Irix 6.x systems for
5481 debugging n32 executables. (Debugging 64-bit executables is not yet
5484 * Unified support for hardware watchpoints in all x86 configurations.
5486 Most (if not all) native x86 configurations support hardware-assisted
5487 breakpoints and watchpoints in a unified manner. This support
5488 implements debug register sharing between watchpoints, which allows to
5489 put a virtually infinite number of watchpoints on the same address,
5490 and also supports watching regions up to 16 bytes with several debug
5493 The new maintenance command `maintenance show-debug-regs' toggles
5494 debugging print-outs in functions that insert, remove, and test
5495 watchpoints and hardware breakpoints.
5497 * Changes in the DJGPP native configuration.
5499 New command ``info dos sysinfo'' displays assorted information about
5500 the CPU, OS, memory, and DPMI server.
5502 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5503 display information about segment descriptors stored in GDT, LDT, and
5506 New commands ``info dos pde'' and ``info dos pte'' display entries
5507 from Page Directory and Page Tables (for now works with CWSDPMI only).
5508 New command ``info dos address-pte'' displays the Page Table entry for
5509 a given linear address.
5511 GDB can now pass command lines longer than 126 characters to the
5512 program being debugged (requires an update to the libdbg.a library
5513 which is part of the DJGPP development kit).
5515 DWARF2 debug info is now supported.
5517 It is now possible to `step' and `next' through calls to `longjmp'.
5519 * Changes in documentation.
5521 All GDB documentation was converted to GFDL, the GNU Free
5522 Documentation License.
5524 Tracepoints-related commands are now fully documented in the GDB
5527 TUI, the Text-mode User Interface, is now documented in the manual.
5529 Tracepoints-related commands are now fully documented in the GDB
5532 The "GDB Internals" manual now has an index. It also includes
5533 documentation of `ui_out' functions, GDB coding standards, x86
5534 hardware watchpoints, and memory region attributes.
5536 * GDB's version number moved to ``version.in''
5538 The Makefile variable VERSION has been replaced by the file
5539 ``version.in''. People creating GDB distributions should update the
5540 contents of this file.
5544 GUD support is now a standard part of the EMACS distribution.
5546 *** Changes in GDB 5.0:
5548 * Improved support for debugging FP programs on x86 targets
5550 Unified and much-improved support for debugging floating-point
5551 programs on all x86 targets. In particular, ``info float'' now
5552 displays the FP registers in the same format on all x86 targets, with
5553 greater level of detail.
5555 * Improvements and bugfixes in hardware-assisted watchpoints
5557 It is now possible to watch array elements, struct members, and
5558 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5559 on x86 targets no longer erroneously trigger when the address is
5562 * Improvements in the native DJGPP version of GDB
5564 The distribution now includes all the scripts and auxiliary files
5565 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5566 machines ``out of the box''.
5568 The DJGPP version can now debug programs that use signals. It is
5569 possible to catch signals that happened in the debuggee, deliver
5570 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5571 would kill the program being debugged.) Programs that hook hardware
5572 interrupts (keyboard, timer, etc.) can also be debugged.
5574 It is now possible to debug DJGPP programs that redirect their
5575 standard handles or switch them to raw (as opposed to cooked) mode, or
5576 even close them. The command ``run < foo > bar'' works as expected,
5577 and ``info terminal'' reports useful information about the debuggee's
5578 terminal, including raw/cooked mode, redirection, etc.
5580 The DJGPP version now uses termios functions for console I/O, which
5581 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5584 DOS-style file names with drive letters are now fully supported by
5587 It is now possible to debug DJGPP programs that switch their working
5588 directory. It is also possible to rerun the debuggee any number of
5589 times without restarting GDB; thus, you can use the same setup,
5590 breakpoints, etc. for many debugging sessions.
5592 * New native configurations
5594 ARM GNU/Linux arm*-*-linux*
5595 PowerPC GNU/Linux powerpc-*-linux*
5599 Motorola MCore mcore-*-*
5600 x86 VxWorks i[3456]86-*-vxworks*
5601 PowerPC VxWorks powerpc-*-vxworks*
5602 TI TMS320C80 tic80-*-*
5604 * OBSOLETE configurations
5606 Altos 3068 m68*-altos-*
5607 Convex c1-*-*, c2-*-*
5609 ARM RISCix arm-*-* (as host)
5612 Configurations that have been declared obsolete will be commented out,
5613 but the code will be left in place. If there is no activity to revive
5614 these configurations before the next release of GDB, the sources will
5615 be permanently REMOVED.
5617 * Gould support removed
5619 Support for the Gould PowerNode and NP1 has been removed.
5621 * New features for SVR4
5623 On SVR4 native platforms (such as Solaris), if you attach to a process
5624 without first loading a symbol file, GDB will now attempt to locate and
5625 load symbols from the running process's executable file.
5627 * Many C++ enhancements
5629 C++ support has been greatly improved. Overload resolution now works properly
5630 in almost all cases. RTTI support is on the way.
5632 * Remote targets can connect to a sub-program
5634 A popen(3) style serial-device has been added. This device starts a
5635 sub-process (such as a stand-alone simulator) and then communicates
5636 with that. The sub-program to run is specified using the syntax
5637 ``|<program> <args>'' vis:
5639 (gdb) set remotedebug 1
5640 (gdb) target extended-remote |mn10300-elf-sim program-args
5642 * MIPS 64 remote protocol
5644 A long standing bug in the mips64 remote protocol where by GDB
5645 expected certain 32 bit registers (ex SR) to be transfered as 32
5646 instead of 64 bits has been fixed.
5648 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5649 added to provide backward compatibility with older versions of GDB.
5651 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5653 The command ``set remotebinarydownload'' command has been replaced by
5654 ``set remote X-packet''. Other commands in ``set remote'' family
5655 include ``set remote P-packet''.
5657 * Breakpoint commands accept ranges.
5659 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5660 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5661 ``tracepoint passcount'' also accepts a range of tracepoints.
5663 * ``apropos'' command added.
5665 The ``apropos'' command searches through command names and
5666 documentation strings, printing out matches, making it much easier to
5667 try to find a command that does what you are looking for.
5671 A new machine oriented interface (MI) has been added to GDB. This
5672 interface is designed for debug environments running GDB as a separate
5673 process. This is part of the long term libGDB project. See the
5674 "GDB/MI" chapter of the GDB manual for further information. It can be
5675 enabled by configuring with:
5677 .../configure --enable-gdbmi
5679 *** Changes in GDB-4.18:
5681 * New native configurations
5683 HP-UX 10.20 hppa*-*-hpux10.20
5684 HP-UX 11.x hppa*-*-hpux11.0*
5685 M68K GNU/Linux m68*-*-linux*
5689 Fujitsu FR30 fr30-*-elf*
5690 Intel StrongARM strongarm-*-*
5691 Mitsubishi D30V d30v-*-*
5693 * OBSOLETE configurations
5695 Gould PowerNode, NP1 np1-*-*, pn-*-*
5697 Configurations that have been declared obsolete will be commented out,
5698 but the code will be left in place. If there is no activity to revive
5699 these configurations before the next release of GDB, the sources will
5700 be permanently REMOVED.
5704 As a compatibility experiment, GDB's source files buildsym.h and
5705 buildsym.c have been converted to pure standard C, no longer
5706 containing any K&R compatibility code. We believe that all systems in
5707 use today either come with a standard C compiler, or have a GCC port
5708 available. If this is not true, please report the affected
5709 configuration to bug-gdb@gnu.org immediately. See the README file for
5710 information about getting a standard C compiler if you don't have one
5715 GDB now uses readline 2.2.
5717 * set extension-language
5719 You can now control the mapping between filename extensions and source
5720 languages by using the `set extension-language' command. For instance,
5721 you can ask GDB to treat .c files as C++ by saying
5722 set extension-language .c c++
5723 The command `info extensions' lists all of the recognized extensions
5724 and their associated languages.
5726 * Setting processor type for PowerPC and RS/6000
5728 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5729 you can use the `set processor' command to specify what variant of the
5730 PowerPC family you are debugging. The command
5734 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5735 following PowerPC and RS6000 variants:
5737 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5738 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5740 403GC IBM PowerPC 403GC
5741 505 Motorola PowerPC 505
5742 860 Motorola PowerPC 860 or 850
5743 601 Motorola PowerPC 601
5744 602 Motorola PowerPC 602
5745 603 Motorola/IBM PowerPC 603 or 603e
5746 604 Motorola PowerPC 604 or 604e
5747 750 Motorola/IBM PowerPC 750 or 750
5749 At the moment, this command just tells GDB what to name the
5750 special-purpose processor registers. Since almost all the affected
5751 registers are inaccessible to user-level programs, this command is
5752 only useful for remote debugging in its present form.
5756 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5757 more extensive support for HP-UX. Added features include shared
5758 library support, kernel threads and hardware watchpoints for 11.00,
5759 support for HP's ANSI C and C++ compilers, and a compatibility mode
5760 for xdb and dbx commands.
5764 HP's donation includes the new concept of catchpoints, which is a
5765 generalization of the old catch command. On HP-UX, it is now possible
5766 to catch exec, fork, and vfork, as well as library loading.
5768 This means that the existing catch command has changed; its first
5769 argument now specifies the type of catch to be set up. See the
5770 output of "help catch" for a list of catchpoint types.
5772 * Debugging across forks
5774 On HP-UX, you can choose which process to debug when a fork() happens
5779 HP has donated a curses-based terminal user interface (TUI). To get
5780 it, build with --enable-tui. Although this can be enabled for any
5781 configuration, at present it only works for native HP debugging.
5783 * GDB remote protocol additions
5785 A new protocol packet 'X' that writes binary data is now available.
5786 Default behavior is to try 'X', then drop back to 'M' if the stub
5787 fails to respond. The settable variable `remotebinarydownload'
5788 allows explicit control over the use of 'X'.
5790 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5791 full 64-bit address. The command
5793 set remoteaddresssize 32
5795 can be used to revert to the old behaviour. For existing remote stubs
5796 the change should not be noticed, as the additional address information
5799 In order to assist in debugging stubs, you may use the maintenance
5800 command `packet' to send any text string to the stub. For instance,
5802 maint packet heythere
5804 sends the packet "$heythere#<checksum>". Note that it is very easy to
5805 disrupt a debugging session by sending the wrong packet at the wrong
5808 The compare-sections command allows you to compare section data on the
5809 target to what is in the executable file without uploading or
5810 downloading, by comparing CRC checksums.
5812 * Tracing can collect general expressions
5814 You may now collect general expressions at tracepoints. This requires
5815 further additions to the target-side stub; see tracepoint.c and
5816 doc/agentexpr.texi for further details.
5818 * mask-address variable for Mips
5820 For Mips targets, you may control the zeroing of the upper 32 bits of
5821 a 64-bit address by entering `set mask-address on'. This is mainly
5822 of interest to users of embedded R4xxx and R5xxx processors.
5824 * Higher serial baud rates
5826 GDB's serial code now allows you to specify baud rates 57600, 115200,
5827 230400, and 460800 baud. (Note that your host system may not be able
5828 to achieve all of these rates.)
5832 The i960 configuration now includes an initial implementation of a
5833 builtin simulator, contributed by Jim Wilson.
5836 *** Changes in GDB-4.17:
5838 * New native configurations
5840 Alpha GNU/Linux alpha*-*-linux*
5841 Unixware 2.x i[3456]86-unixware2*
5842 Irix 6.x mips*-sgi-irix6*
5843 PowerPC GNU/Linux powerpc-*-linux*
5844 PowerPC Solaris powerpcle-*-solaris*
5845 Sparc GNU/Linux sparc-*-linux*
5846 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5850 Argonaut Risc Chip (ARC) arc-*-*
5851 Hitachi H8/300S h8300*-*-*
5852 Matsushita MN10200 w/simulator mn10200-*-*
5853 Matsushita MN10300 w/simulator mn10300-*-*
5854 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5855 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5856 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5857 Mitsubishi D10V w/simulator d10v-*-*
5858 Mitsubishi M32R/D w/simulator m32r-*-elf*
5859 Tsqware Sparclet sparclet-*-*
5860 NEC V850 w/simulator v850-*-*
5862 * New debugging protocols
5864 ARM with RDI protocol arm*-*-*
5865 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5866 DDB and LSI variants of PMON protocol mips*-*-*
5867 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5868 PowerPC with SDS protocol powerpc{,le}-*-eabi
5869 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5873 All configurations can now understand and use the DWARF 2 debugging
5874 format. The choice is automatic, if the symbol file contains DWARF 2
5879 GDB now includes basic Java language support. This support is
5880 only useful with Java compilers that produce native machine code.
5882 * solib-absolute-prefix and solib-search-path
5884 For SunOS and SVR4 shared libraries, you may now set the prefix for
5885 loading absolute shared library symbol files, and the search path for
5886 locating non-absolute shared library symbol files.
5888 * Live range splitting
5890 GDB can now effectively debug code for which GCC has performed live
5891 range splitting as part of its optimization. See gdb/doc/LRS for
5892 more details on the expected format of the stabs information.
5896 GDB's support for the GNU Hurd, including thread debugging, has been
5897 updated to work with current versions of the Hurd.
5901 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5902 instruction set. ARM GDB automatically detects when Thumb
5903 instructions are in use, and adjusts disassembly and backtracing
5908 GDB's MIPS target configurations now handle the MIP16 16-bit
5913 GDB now includes support for overlays; if an executable has been
5914 linked such that multiple sections are based at the same address, GDB
5915 will decide which section to use for symbolic info. You can choose to
5916 control the decision manually, using overlay commands, or implement
5917 additional target-side support and use "overlay load-target" to bring
5918 in the overlay mapping. Do "help overlay" for more detail.
5922 The command "info symbol <address>" displays information about
5923 the symbol at the specified address.
5927 The standard remote protocol now includes an extension that allows
5928 asynchronous collection and display of trace data. This requires
5929 extensive support in the target-side debugging stub. Tracing mode
5930 includes a new interaction mode in GDB and new commands: see the
5931 file tracepoint.c for more details.
5935 Configurations for embedded MIPS now include a simulator contributed
5936 by Cygnus Solutions. The simulator supports the instruction sets
5937 of most MIPS variants.
5941 Sparc configurations may now include the ERC32 simulator contributed
5942 by the European Space Agency. The simulator is not built into
5943 Sparc targets by default; configure with --enable-sim to include it.
5947 For target configurations that may include multiple variants of a
5948 basic architecture (such as MIPS and SH), you may now set the
5949 architecture explicitly. "set arch" sets, "info arch" lists
5950 the possible architectures.
5952 *** Changes in GDB-4.16:
5954 * New native configurations
5956 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5957 M68K NetBSD m68k-*-netbsd*
5958 PowerPC AIX 4.x powerpc-*-aix*
5959 PowerPC MacOS powerpc-*-macos*
5960 PowerPC Windows NT powerpcle-*-cygwin32
5961 RS/6000 AIX 4.x rs6000-*-aix4*
5965 ARM with RDP protocol arm-*-*
5966 I960 with MON960 i960-*-coff
5967 MIPS VxWorks mips*-*-vxworks*
5968 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5969 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5971 Matra Sparclet sparclet-*-*
5975 The powerpc-eabi configuration now includes the PSIM simulator,
5976 contributed by Andrew Cagney, with assistance from Mike Meissner.
5977 PSIM is a very elaborate model of the PowerPC, including not only
5978 basic instruction set execution, but also details of execution unit
5979 performance and I/O hardware. See sim/ppc/README for more details.
5983 GDB now works with Solaris 2.5.
5985 * Windows 95/NT native
5987 GDB will now work as a native debugger on Windows 95 and Windows NT.
5988 To build it from source, you must use the "gnu-win32" environment,
5989 which uses a DLL to emulate enough of Unix to run the GNU tools.
5990 Further information, binaries, and sources are available at
5991 ftp.cygnus.com, under pub/gnu-win32.
5993 * dont-repeat command
5995 If a user-defined command includes the command `dont-repeat', then the
5996 command will not be repeated if the user just types return. This is
5997 useful if the command is time-consuming to run, so that accidental
5998 extra keystrokes don't run the same command many times.
6000 * Send break instead of ^C
6002 The standard remote protocol now includes an option to send a break
6003 rather than a ^C to the target in order to interrupt it. By default,
6004 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6006 * Remote protocol timeout
6008 The standard remote protocol includes a new variable `remotetimeout'
6009 that allows you to set the number of seconds before GDB gives up trying
6010 to read from the target. The default value is 2.
6012 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6014 By default GDB will automatically keep track of objects as they are
6015 loaded and unloaded by the dynamic linker. By using the command `set
6016 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6017 when shared library events occur, thus allowing you to set breakpoints
6018 in shared libraries which are explicitly loaded by the inferior.
6020 Note this feature does not work on hpux8. On hpux9 you must link
6021 /usr/lib/end.o into your program. This feature should work
6022 automatically on hpux10.
6024 * Irix 5.x hardware watchpoint support
6026 Irix 5 configurations now support the use of hardware watchpoints.
6028 * Mips protocol "SYN garbage limit"
6030 When debugging a Mips target using the `target mips' protocol, you
6031 may set the number of characters that GDB will ignore by setting
6032 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6033 every character. The default value is 1050.
6035 * Recording and replaying remote debug sessions
6037 If you set `remotelogfile' to the name of a file, gdb will write to it
6038 a recording of a remote debug session. This recording may then be
6039 replayed back to gdb using "gdbreplay". See gdbserver/README for
6040 details. This is useful when you have a problem with GDB while doing
6041 remote debugging; you can make a recording of the session and send it
6042 to someone else, who can then recreate the problem.
6044 * Speedups for remote debugging
6046 GDB includes speedups for downloading and stepping MIPS systems using
6047 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6048 and more efficient S-record downloading.
6050 * Memory use reductions and statistics collection
6052 GDB now uses less memory and reports statistics about memory usage.
6053 Try the `maint print statistics' command, for example.
6055 *** Changes in GDB-4.15:
6057 * Psymtabs for XCOFF
6059 The symbol reader for AIX GDB now uses partial symbol tables. This
6060 can greatly improve startup time, especially for large executables.
6062 * Remote targets use caching
6064 Remote targets now use a data cache to speed up communication with the
6065 remote side. The data cache could lead to incorrect results because
6066 it doesn't know about volatile variables, thus making it impossible to
6067 debug targets which use memory mapped I/O devices. `set remotecache
6068 off' turns the the data cache off.
6070 * Remote targets may have threads
6072 The standard remote protocol now includes support for multiple threads
6073 in the target system, using new protocol commands 'H' and 'T'. See
6074 gdb/remote.c for details.
6078 If GDB is configured with `--enable-netrom', then it will include
6079 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6080 acts as though it is a bank of ROM on the target board, but you can
6081 write into it over the network. GDB's support consists only of
6082 support for fast loading into the emulated ROM; to debug, you must use
6083 another protocol, such as standard remote protocol. The usual
6084 sequence is something like
6086 target nrom <netrom-hostname>
6088 target remote <netrom-hostname>:1235
6092 GDB now includes support for the Apple Macintosh, as a host only. It
6093 may be run as either an MPW tool or as a standalone application, and
6094 it can debug through the serial port. All the usual GDB commands are
6095 available, but to the target command, you must supply "serial" as the
6096 device type instead of "/dev/ttyXX". See mpw-README in the main
6097 directory for more information on how to build. The MPW configuration
6098 scripts */mpw-config.in support only a few targets, and only the
6099 mips-idt-ecoff target has been tested.
6103 GDB configuration now uses autoconf. This is not user-visible,
6104 but does simplify configuration and building.
6108 GDB now supports hpux10.
6110 *** Changes in GDB-4.14:
6112 * New native configurations
6114 x86 FreeBSD i[345]86-*-freebsd
6115 x86 NetBSD i[345]86-*-netbsd
6116 NS32k NetBSD ns32k-*-netbsd
6117 Sparc NetBSD sparc-*-netbsd
6121 A29K VxWorks a29k-*-vxworks
6122 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6123 CPU32 EST-300 emulator m68*-*-est*
6124 PowerPC ELF powerpc-*-elf
6127 * Alpha OSF/1 support for procfs
6129 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6130 possible to attach to running processes. As the mounting of the /proc
6131 filesystem is optional on the Alpha, GDB automatically determines
6132 the availability of /proc during startup. This can lead to problems
6133 if /proc is unmounted after GDB has been started.
6135 * Arguments to user-defined commands
6137 User commands may accept up to 10 arguments separated by whitespace.
6138 Arguments are accessed within the user command via $arg0..$arg9. A
6141 print $arg0 + $arg1 + $arg2
6143 To execute the command use:
6146 Defines the command "adder" which prints the sum of its three arguments.
6147 Note the arguments are text substitutions, so they may reference variables,
6148 use complex expressions, or even perform inferior function calls.
6150 * New `if' and `while' commands
6152 This makes it possible to write more sophisticated user-defined
6153 commands. Both commands take a single argument, which is the
6154 expression to evaluate, and must be followed by the commands to
6155 execute, one per line, if the expression is nonzero, the list being
6156 terminated by the word `end'. The `if' command list may include an
6157 `else' word, which causes the following commands to be executed only
6158 if the expression is zero.
6160 * Fortran source language mode
6162 GDB now includes partial support for Fortran 77. It will recognize
6163 Fortran programs and can evaluate a subset of Fortran expressions, but
6164 variables and functions may not be handled correctly. GDB will work
6165 with G77, but does not yet know much about symbols emitted by other
6168 * Better HPUX support
6170 Most debugging facilities now work on dynamic executables for HPPAs
6171 running hpux9 or later. You can attach to running dynamically linked
6172 processes, but by default the dynamic libraries will be read-only, so
6173 for instance you won't be able to put breakpoints in them. To change
6174 that behavior do the following before running the program:
6180 This will cause the libraries to be mapped private and read-write.
6181 To revert to the normal behavior, do this:
6187 You cannot set breakpoints or examine data in the library until after
6188 the library is loaded if the function/data symbols do not have
6191 GDB can now also read debug symbols produced by the HP C compiler on
6192 HPPAs (sorry, no C++, Fortran or 68k support).
6194 * Target byte order now dynamically selectable
6196 You can choose which byte order to use with a target system, via the
6197 commands "set endian big" and "set endian little", and you can see the
6198 current setting by using "show endian". You can also give the command
6199 "set endian auto", in which case GDB will use the byte order
6200 associated with the executable. Currently, only embedded MIPS
6201 configurations support dynamic selection of target byte order.
6203 * New DOS host serial code
6205 This version uses DPMI interrupts to handle buffered I/O, so you
6206 no longer need to run asynctsr when debugging boards connected to
6209 *** Changes in GDB-4.13:
6211 * New "complete" command
6213 This lists all the possible completions for the rest of the line, if it
6214 were to be given as a command itself. This is intended for use by emacs.
6216 * Trailing space optional in prompt
6218 "set prompt" no longer adds a space for you after the prompt you set. This
6219 allows you to set a prompt which ends in a space or one that does not.
6221 * Breakpoint hit counts
6223 "info break" now displays a count of the number of times the breakpoint
6224 has been hit. This is especially useful in conjunction with "ignore"; you
6225 can ignore a large number of breakpoint hits, look at the breakpoint info
6226 to see how many times the breakpoint was hit, then run again, ignoring one
6227 less than that number, and this will get you quickly to the last hit of
6230 * Ability to stop printing at NULL character
6232 "set print null-stop" will cause GDB to stop printing the characters of
6233 an array when the first NULL is encountered. This is useful when large
6234 arrays actually contain only short strings.
6236 * Shared library breakpoints
6238 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6239 breakpoints in shared libraries before the executable is run.
6241 * Hardware watchpoints
6243 There is a new hardware breakpoint for the watch command for sparclite
6244 targets. See gdb/sparclite/hw_breakpoint.note.
6246 Hardware watchpoints are also now supported under GNU/Linux.
6250 Annotations have been added. These are for use with graphical interfaces,
6251 and are still experimental. Currently only gdba.el uses these.
6253 * Improved Irix 5 support
6255 GDB now works properly with Irix 5.2.
6257 * Improved HPPA support
6259 GDB now works properly with the latest GCC and GAS.
6261 * New native configurations
6263 Sequent PTX4 i[34]86-sequent-ptx4
6264 HPPA running OSF/1 hppa*-*-osf*
6265 Atari TT running SVR4 m68*-*-sysv4*
6266 RS/6000 LynxOS rs6000-*-lynxos*
6270 OS/9000 i[34]86-*-os9k
6271 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6274 * Hitachi SH7000 and E7000-PC ICE support
6276 There is now support for communicating with the Hitachi E7000-PC ICE.
6277 This is available automatically when GDB is configured for the SH.
6281 As usual, a variety of small fixes and improvements, both generic
6282 and configuration-specific. See the ChangeLog for more detail.
6284 *** Changes in GDB-4.12:
6286 * Irix 5 is now supported
6290 GDB-4.12 on the HPPA has a number of changes which make it unable
6291 to debug the output from the currently released versions of GCC and
6292 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6293 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6294 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6297 *** Changes in GDB-4.11:
6299 * User visible changes:
6303 The "set remotedebug" option is now consistent between the mips remote
6304 target, remote targets using the gdb-specific protocol, UDI (AMD's
6305 debug protocol for the 29k) and the 88k bug monitor. It is now an
6306 integer specifying a debug level (normally 0 or 1, but 2 means more
6307 debugging info for the mips target).
6309 * DEC Alpha native support
6311 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6312 debug info, but GDB works fairly well with the DEC compiler and should
6313 work with a future GCC release. See the README file for a few
6314 Alpha-specific notes.
6316 * Preliminary thread implementation
6318 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6320 * LynxOS native and target support for 386
6322 This release has been hosted on LynxOS 2.2, and also can be configured
6323 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6326 * Improvements in C++ mangling/demangling.
6328 This release has much better g++ debugging, specifically in name
6329 mangling/demangling, virtual function calls, print virtual table,
6330 call methods, ...etc.
6332 *** Changes in GDB-4.10:
6334 * User visible changes:
6336 Remote debugging using the GDB-specific (`target remote') protocol now
6337 supports the `load' command. This is only useful if you have some
6338 other way of getting the stub to the target system, and you can put it
6339 somewhere in memory where it won't get clobbered by the download.
6341 Filename completion now works.
6343 When run under emacs mode, the "info line" command now causes the
6344 arrow to point to the line specified. Also, "info line" prints
6345 addresses in symbolic form (as well as hex).
6347 All vxworks based targets now support a user settable option, called
6348 vxworks-timeout. This option represents the number of seconds gdb
6349 should wait for responses to rpc's. You might want to use this if
6350 your vxworks target is, perhaps, a slow software simulator or happens
6351 to be on the far side of a thin network line.
6355 This release contains support for using a DEC alpha as a GDB host for
6356 cross debugging. Native alpha debugging is not supported yet.
6359 *** Changes in GDB-4.9:
6363 This is the first GDB release which is accompanied by a matching testsuite.
6364 The testsuite requires installation of dejagnu, which should be available
6365 via ftp from most sites that carry GNU software.
6369 'Cfront' style demangling has had its name changed to 'ARM' style, to
6370 emphasize that it was written from the specifications in the C++ Annotated
6371 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6372 disclaimers, it still generated too much confusion with users attempting to
6373 use gdb with AT&T cfront.
6377 GDB now uses a standard remote interface to a simulator library.
6378 So far, the library contains simulators for the Zilog Z8001/2, the
6379 Hitachi H8/300, H8/500 and Super-H.
6381 * New targets supported
6383 H8/300 simulator h8300-hitachi-hms or h8300hms
6384 H8/500 simulator h8500-hitachi-hms or h8500hms
6385 SH simulator sh-hitachi-hms or sh
6386 Z8000 simulator z8k-zilog-none or z8ksim
6387 IDT MIPS board over serial line mips-idt-ecoff
6389 Cross-debugging to GO32 targets is supported. It requires a custom
6390 version of the i386-stub.c module which is integrated with the
6391 GO32 memory extender.
6393 * New remote protocols
6395 MIPS remote debugging protocol.
6397 * New source languages supported
6399 This version includes preliminary support for Chill, a Pascal like language
6400 used by telecommunications companies. Chill support is also being integrated
6401 into the GNU compiler, but we don't know when it will be publically available.
6404 *** Changes in GDB-4.8:
6406 * HP Precision Architecture supported
6408 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6409 version of this support was available as a set of patches from the
6410 University of Utah. GDB does not support debugging of programs
6411 compiled with the HP compiler, because HP will not document their file
6412 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6413 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6415 Many problems in the preliminary version have been fixed.
6417 * Faster and better demangling
6419 We have improved template demangling and fixed numerous bugs in the GNU style
6420 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6421 character types (wchar_t) are now supported. Demangling of each symbol is now
6422 only done once, and is cached when the symbol table for a file is read in.
6423 This results in a small increase in memory usage for C programs, a moderate
6424 increase in memory usage for C++ programs, and a fantastic speedup in
6427 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6428 from the specifications in the Annotated Reference Manual, which AT&T's
6429 compiler does not actually implement.
6431 * G++ multiple inheritance compiler problem
6433 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6434 inheritance lattices was reworked to properly discover ambiguities. We
6435 recently found an example which causes this new algorithm to fail in a
6436 very subtle way, producing bad debug information for those classes.
6437 The file 'gcc.patch' (in this directory) can be applied to gcc to
6438 circumvent the problem. A future GCC release will contain a complete
6441 The previous G++ debug info problem (mentioned below for the gdb-4.7
6442 release) is fixed in gcc version 2.3.2.
6444 * Improved configure script
6446 The `configure' script will now attempt to guess your system type if
6447 you don't supply a host system type. The old scheme of supplying a
6448 host system triplet is preferable over using this. All the magic is
6449 done in the new `config.guess' script. Examine it for details.
6451 We have also brought our configure script much more in line with the FSF's
6452 version. It now supports the --with-xxx options. In particular,
6453 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6454 The resulting GDB will not be able to read arbitrary object file formats --
6455 only the format ``expected'' to be used on the configured target system.
6456 We hope to make this the default in a future release.
6458 * Documentation improvements
6460 There's new internal documentation on how to modify GDB, and how to
6461 produce clean changes to the code. We implore people to read it
6462 before submitting changes.
6464 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6465 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6466 `info' files are also provided. To build `info' files from scratch,
6467 you will need the latest `makeinfo' release, which will be available in
6468 a future texinfo-X.Y release.
6470 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6471 We're not sure exactly which versions have this problem, but it has
6472 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6473 or better. If that isn't possible, there is a patch in
6474 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6475 around this problem.
6479 GDB now supports array constants that can be used in expressions typed in by
6480 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6481 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6484 The new directory `gdb/sparclite' contains a program that demonstrates
6485 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6487 * New native hosts supported
6489 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6490 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6492 * New targets supported
6494 AMD 29k family via UDI a29k-amd-udi or udi29k
6496 * New file formats supported
6498 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6499 HPUX core files, and SCO 3.2v2 core files.
6503 Attaching to processes now works again; thanks for the many bug reports.
6505 We have also stomped on a bunch of core dumps caused by
6506 printf_filtered("%s") problems.
6508 We eliminated a copyright problem on the rpc and ptrace header files
6509 for VxWorks, which was discovered at the last minute during the 4.7
6510 release. You should now be able to build a VxWorks GDB.
6512 You can now interrupt gdb while an attached process is running. This
6513 will cause the attached process to stop, and give control back to GDB.
6515 We fixed problems caused by using too many file descriptors
6516 for reading symbols from object files and libraries. This was
6517 especially a problem for programs that used many (~100) shared
6520 The `step' command now only enters a subroutine if there is line number
6521 information for the subroutine. Otherwise it acts like the `next'
6522 command. Previously, `step' would enter subroutines if there was
6523 any debugging information about the routine. This avoids problems
6524 when using `cc -g1' on MIPS machines.
6526 * Internal improvements
6528 GDB's internal interfaces have been improved to make it easier to support
6529 debugging of multiple languages in the future.
6531 GDB now uses a common structure for symbol information internally.
6532 Minimal symbols (derived from linkage symbols in object files), partial
6533 symbols (from a quick scan of debug information), and full symbols
6534 contain a common subset of information, making it easier to write
6535 shared code that handles any of them.
6537 * New command line options
6539 We now accept --silent as an alias for --quiet.
6543 The memory-mapped-malloc library is now licensed under the GNU Library
6544 General Public License.
6546 *** Changes in GDB-4.7:
6548 * Host/native/target split
6550 GDB has had some major internal surgery to untangle the support for
6551 hosts and remote targets. Now, when you configure GDB for a remote
6552 target, it will no longer load in all of the support for debugging
6553 local programs on the host. When fully completed and tested, this will
6554 ensure that arbitrary host/target combinations are possible.
6556 The primary conceptual shift is to separate the non-portable code in
6557 GDB into three categories. Host specific code is required any time GDB
6558 is compiled on that host, regardless of the target. Target specific
6559 code relates to the peculiarities of the target, but can be compiled on
6560 any host. Native specific code is everything else: it can only be
6561 built when the host and target are the same system. Child process
6562 handling and core file support are two common `native' examples.
6564 GDB's use of /proc for controlling Unix child processes is now cleaner.
6565 It has been split out into a single module under the `target_ops' vector,
6566 plus two native-dependent functions for each system that uses /proc.
6568 * New hosts supported
6570 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6571 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6572 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6574 * New targets supported
6576 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6577 68030 and CPU32 m68030-*-*, m68332-*-*
6579 * New native hosts supported
6581 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6582 (386bsd is not well tested yet)
6583 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6585 * New file formats supported
6587 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6588 supports reading of `a.out.adobe' object files, which are an a.out
6589 format extended with minimal information about multiple sections.
6593 `show copying' is the same as the old `info copying'.
6594 `show warranty' is the same as `info warrantee'.
6595 These were renamed for consistency. The old commands continue to work.
6597 `info handle' is a new alias for `info signals'.
6599 You can now define pre-command hooks, which attach arbitrary command
6600 scripts to any command. The commands in the hook will be executed
6601 prior to the user's command. You can also create a hook which will be
6602 executed whenever the program stops. See gdb.texinfo.
6606 We now deal with Cfront style name mangling, and can even extract type
6607 info from mangled symbols. GDB can automatically figure out which
6608 symbol mangling style your C++ compiler uses.
6610 Calling of methods and virtual functions has been improved as well.
6614 The crash that occured when debugging Sun Ansi-C compiled binaries is
6615 fixed. This was due to mishandling of the extra N_SO stabs output
6618 We also finally got Ultrix 4.2 running in house, and fixed core file
6619 support, with help from a dozen people on the net.
6621 John M. Farrell discovered that the reason that single-stepping was so
6622 slow on all of the Mips based platforms (primarily SGI and DEC) was
6623 that we were trying to demangle and lookup a symbol used for internal
6624 purposes on every instruction that was being stepped through. Changing
6625 the name of that symbol so that it couldn't be mistaken for a C++
6626 mangled symbol sped things up a great deal.
6628 Rich Pixley sped up symbol lookups in general by getting much smarter
6629 about when C++ symbol mangling is necessary. This should make symbol
6630 completion (TAB on the command line) much faster. It's not as fast as
6631 we'd like, but it's significantly faster than gdb-4.6.
6635 A new user controllable variable 'call_scratch_address' can
6636 specify the location of a scratch area to be used when GDB
6637 calls a function in the target. This is necessary because the
6638 usual method of putting the scratch area on the stack does not work
6639 in systems that have separate instruction and data spaces.
6641 We integrated changes to support the 29k UDI (Universal Debugger
6642 Interface), but discovered at the last minute that we didn't have all
6643 of the appropriate copyright paperwork. We are working with AMD to
6644 resolve this, and hope to have it available soon.
6648 We have sped up the remote serial line protocol, especially for targets
6649 with lots of registers. It now supports a new `expedited status' ('T')
6650 message which can be used in place of the existing 'S' status message.
6651 This allows the remote stub to send only the registers that GDB
6652 needs to make a quick decision about single-stepping or conditional
6653 breakpoints, eliminating the need to fetch the entire register set for
6654 each instruction being stepped through.
6656 The GDB remote serial protocol now implements a write-through cache for
6657 registers, only re-reading the registers if the target has run.
6659 There is also a new remote serial stub for SPARC processors. You can
6660 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6661 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6662 processor with a serial port.
6666 Configure.in files have become much easier to read and modify. A new
6667 `table driven' format makes it more obvious what configurations are
6668 supported, and what files each one uses.
6672 There is a new opcodes library which will eventually contain all of the
6673 disassembly routines and opcode tables. At present, it only contains
6674 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6675 disassembler (binutils/objdump) to share these routines.
6677 The libiberty library is now copylefted under the GNU Library General
6678 Public License. This allows more liberal use, and was done so libg++
6679 can use it. This makes no difference to GDB, since the Library License
6680 grants all the rights from the General Public License.
6684 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6685 reference to the stabs symbol info used by the debugger. It is (as far
6686 as we know) the only published document on this fascinating topic. We
6687 encourage you to read it, compare it to the stabs information on your
6688 system, and send improvements on the document in general (to
6689 bug-gdb@prep.ai.mit.edu).
6691 And, of course, many bugs have been fixed.
6694 *** Changes in GDB-4.6:
6696 * Better support for C++ function names
6698 GDB now accepts as input the "demangled form" of C++ overloaded function
6699 names and member function names, and can do command completion on such names
6700 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6701 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6702 Make use of command completion, it is your friend.
6704 GDB also now accepts a variety of C++ mangled symbol formats. They are
6705 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6706 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6707 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6708 for the list of formats.
6710 * G++ symbol mangling problem
6712 Recent versions of gcc have a bug in how they emit debugging information for
6713 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6714 directory) can be applied to gcc to fix the problem. Alternatively, if you
6715 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6716 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6717 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6720 * New 'maintenance' command
6722 All of the commands related to hacking GDB internals have been moved out of
6723 the main command set, and now live behind the 'maintenance' command. This
6724 can also be abbreviated as 'mt'. The following changes were made:
6726 dump-me -> maintenance dump-me
6727 info all-breakpoints -> maintenance info breakpoints
6728 printmsyms -> maintenance print msyms
6729 printobjfiles -> maintenance print objfiles
6730 printpsyms -> maintenance print psymbols
6731 printsyms -> maintenance print symbols
6733 The following commands are new:
6735 maintenance demangle Call internal GDB demangler routine to
6736 demangle a C++ link name and prints the result.
6737 maintenance print type Print a type chain for a given symbol
6739 * Change to .gdbinit file processing
6741 We now read the $HOME/.gdbinit file before processing the argv arguments
6742 (e.g. reading symbol files or core files). This allows global parameters to
6743 be set, which will apply during the symbol reading. The ./.gdbinit is still
6744 read after argv processing.
6746 * New hosts supported
6748 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6750 GNU/Linux support i386-unknown-linux or linux
6752 We are also including code to support the HP/PA running BSD and HPUX. This
6753 is almost guaranteed not to work, as we didn't have time to test or build it
6754 for this release. We are including it so that the more adventurous (or
6755 masochistic) of you can play with it. We also had major problems with the
6756 fact that the compiler that we got from HP doesn't support the -g option.
6759 * New targets supported
6761 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6763 * More smarts about finding #include files
6765 GDB now remembers the compilation directory for all include files, and for
6766 all files from which C is generated (like yacc and lex sources). This
6767 greatly improves GDB's ability to find yacc/lex sources, and include files,
6768 especially if you are debugging your program from a directory different from
6769 the one that contains your sources.
6771 We also fixed a bug which caused difficulty with listing and setting
6772 breakpoints in include files which contain C code. (In the past, you had to
6773 try twice in order to list an include file that you hadn't looked at before.)
6775 * Interesting infernals change
6777 GDB now deals with arbitrary numbers of sections, where the symbols for each
6778 section must be relocated relative to that section's landing place in the
6779 target's address space. This work was needed to support ELF with embedded
6780 stabs used by Solaris-2.0.
6782 * Bug fixes (of course!)
6784 There have been loads of fixes for the following things:
6785 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6786 i960, stabs, DOS(GO32), procfs, etc...
6788 See the ChangeLog for details.
6790 *** Changes in GDB-4.5:
6792 * New machines supported (host and target)
6794 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6796 SGI Irix-4.x mips-sgi-irix4 or iris4
6798 * New malloc package
6800 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6801 Mmalloc is capable of handling mutiple heaps of memory. It is also
6802 capable of saving a heap to a file, and then mapping it back in later.
6803 This can be used to greatly speedup the startup of GDB by using a
6804 pre-parsed symbol table which lives in a mmalloc managed heap. For
6805 more details, please read mmalloc/mmalloc.texi.
6809 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6810 'help info proc' for details.
6812 * MIPS ecoff symbol table format
6814 The code that reads MIPS symbol table format is now supported on all hosts.
6815 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6818 * File name changes for MS-DOS
6820 Many files in the config directories have been renamed to make it easier to
6821 support GDB on MS-DOSe systems (which have very restrictive file name
6822 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6823 environment) is close to working but has some remaining problems. Note
6824 that debugging of DOS programs is not supported, due to limitations
6825 in the ``operating system'', but it can be used to host cross-debugging.
6827 * Cross byte order fixes
6829 Many fixes have been made to support cross debugging of Sparc and MIPS
6830 targets from hosts whose byte order differs.
6832 * New -mapped and -readnow options
6834 If memory-mapped files are available on your system through the 'mmap'
6835 system call, you can use the -mapped option on the `file' or
6836 `symbol-file' commands to cause GDB to write the symbols from your
6837 program into a reusable file. If the program you are debugging is
6838 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6839 Future GDB debugging sessions will notice the presence of this file,
6840 and will quickly map in symbol information from it, rather than reading
6841 the symbol table from the executable program. Using the '-mapped'
6842 option in a GDB `file' or `symbol-file' command has the same effect as
6843 starting GDB with the '-mapped' command-line option.
6845 You can cause GDB to read the entire symbol table immediately by using
6846 the '-readnow' option with any of the commands that load symbol table
6847 information (or on the GDB command line). This makes the command
6848 slower, but makes future operations faster.
6850 The -mapped and -readnow options are typically combined in order to
6851 build a `fred.syms' file that contains complete symbol information.
6852 A simple GDB invocation to do nothing but build a `.syms' file for future
6855 gdb -batch -nx -mapped -readnow programname
6857 The `.syms' file is specific to the host machine on which GDB is run.
6858 It holds an exact image of GDB's internal symbol table. It cannot be
6859 shared across multiple host platforms.
6861 * longjmp() handling
6863 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6864 siglongjmp() without losing control. This feature has not yet been ported to
6865 all systems. It currently works on many 386 platforms, all MIPS-based
6866 platforms (SGI, DECstation, etc), and Sun3/4.
6870 Preliminary work has been put in to support the new Solaris OS from Sun. At
6871 this time, it can control and debug processes, but it is not capable of
6876 As always, many many bug fixes. The major areas were with g++, and mipsread.
6877 People using the MIPS-based platforms should experience fewer mysterious
6878 crashes and trashed symbol tables.
6880 *** Changes in GDB-4.4:
6882 * New machines supported (host and target)
6884 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6886 BSD Reno on Vax vax-dec-bsd
6887 Ultrix on Vax vax-dec-ultrix
6889 * New machines supported (target)
6891 AMD 29000 embedded, using EBMON a29k-none-none
6895 GDB continues to improve its handling of C++. `References' work better.
6896 The demangler has also been improved, and now deals with symbols mangled as
6897 per the Annotated C++ Reference Guide.
6899 GDB also now handles `stabs' symbol information embedded in MIPS
6900 `ecoff' symbol tables. Since the ecoff format was not easily
6901 extensible to handle new languages such as C++, this appeared to be a
6902 good way to put C++ debugging info into MIPS binaries. This option
6903 will be supported in the GNU C compiler, version 2, when it is
6906 * New features for SVR4
6908 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6909 shared libraries. Debugging dynamically linked programs should present
6910 only minor differences from debugging statically linked programs.
6912 The `info proc' command will print out information about any process
6913 on an SVR4 system (including the one you are debugging). At the moment,
6914 it prints the address mappings of the process.
6916 If you bring up GDB on another SVR4 system, please send mail to
6917 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6919 * Better dynamic linking support in SunOS
6921 Reading symbols from shared libraries which contain debugging symbols
6922 now works properly. However, there remain issues such as automatic
6923 skipping of `transfer vector' code during function calls, which
6924 make it harder to debug code in a shared library, than to debug the
6925 same code linked statically.
6929 GDB is now using the latest `getopt' routines from the FSF. This
6930 version accepts the -- prefix for options with long names. GDB will
6931 continue to accept the old forms (-option and +option) as well.
6932 Various single letter abbreviations for options have been explicity
6933 added to the option table so that they won't get overshadowed in the
6934 future by other options that begin with the same letter.
6938 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6939 Many assorted bugs have been handled. Many more remain to be handled.
6940 See the various ChangeLog files (primarily in gdb and bfd) for details.
6943 *** Changes in GDB-4.3:
6945 * New machines supported (host and target)
6947 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6948 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6949 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6951 * Almost SCO Unix support
6953 We had hoped to support:
6954 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6955 (except for core file support), but we discovered very late in the release
6956 that it has problems with process groups that render gdb unusable. Sorry
6957 about that. I encourage people to fix it and post the fixes.
6959 * Preliminary ELF and DWARF support
6961 GDB can read ELF object files on System V Release 4, and can handle
6962 debugging records for C, in DWARF format, in ELF files. This support
6963 is preliminary. If you bring up GDB on another SVR4 system, please
6964 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6969 GDB now uses the latest `readline' library. One user-visible change
6970 is that two tabs will list possible command completions, which previously
6971 required typing M-? (meta-question mark, or ESC ?).
6975 The `stepi' bug that many of you noticed has been squashed.
6976 Many bugs in C++ have been handled. Many more remain to be handled.
6977 See the various ChangeLog files (primarily in gdb and bfd) for details.
6979 * State of the MIPS world (in case you wondered):
6981 GDB can understand the symbol tables emitted by the compilers
6982 supplied by most vendors of MIPS-based machines, including DEC. These
6983 symbol tables are in a format that essentially nobody else uses.
6985 Some versions of gcc come with an assembler post-processor called
6986 mips-tfile. This program is required if you want to do source-level
6987 debugging of gcc-compiled programs. I believe FSF does not ship
6988 mips-tfile with gcc version 1, but it will eventually come with gcc
6991 Debugging of g++ output remains a problem. g++ version 1.xx does not
6992 really support it at all. (If you're lucky, you should be able to get
6993 line numbers and stack traces to work, but no parameters or local
6994 variables.) With some work it should be possible to improve the
6997 When gcc version 2 is released, you will have somewhat better luck.
6998 However, even then you will get confusing results for inheritance and
7001 We will eventually provide full debugging of g++ output on
7002 DECstations. This will probably involve some kind of stabs-in-ecoff
7003 encapulation, but the details have not been worked out yet.
7006 *** Changes in GDB-4.2:
7008 * Improved configuration
7010 Only one copy of `configure' exists now, and it is not self-modifying.
7011 Porting BFD is simpler.
7015 The `step' and `next' commands now only stop at the first instruction
7016 of a source line. This prevents the multiple stops that used to occur
7017 in switch statements, for-loops, etc. `Step' continues to stop if a
7018 function that has debugging information is called within the line.
7022 Lots of small bugs fixed. More remain.
7024 * New host supported (not target)
7026 Intel 386 PC clone running Mach i386-none-mach
7029 *** Changes in GDB-4.1:
7031 * Multiple source language support
7033 GDB now has internal scaffolding to handle several source languages.
7034 It determines the type of each source file from its filename extension,
7035 and will switch expression parsing and number formatting to match the
7036 language of the function in the currently selected stack frame.
7037 You can also specifically set the language to be used, with
7038 `set language c' or `set language modula-2'.
7042 GDB now has preliminary support for the GNU Modula-2 compiler,
7043 currently under development at the State University of New York at
7044 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7045 continue through the fall of 1991 and into 1992.
7047 Other Modula-2 compilers are currently not supported, and attempting to
7048 debug programs compiled with them will likely result in an error as the
7049 symbol table is read. Feel free to work on it, though!
7051 There are hooks in GDB for strict type checking and range checking,
7052 in the `Modula-2 philosophy', but they do not currently work.
7056 GDB can now write to executable and core files (e.g. patch
7057 a variable's value). You must turn this switch on, specify
7058 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7059 by assigning a new value to a variable. Modifications take
7062 * Automatic SunOS shared library reading
7064 When you run your program, GDB automatically determines where its
7065 shared libraries (if any) have been loaded, and reads their symbols.
7066 The `share' command is no longer needed. This also works when
7067 examining core files.
7071 You can specify the number of lines that the `list' command shows.
7074 * New machines supported (host and target)
7076 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7077 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7078 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7080 * New hosts supported (not targets)
7082 IBM RT/PC: romp-ibm-aix or rtpc
7084 * New targets supported (not hosts)
7086 AMD 29000 embedded with COFF a29k-none-coff
7087 AMD 29000 embedded with a.out a29k-none-aout
7088 Ultracomputer remote kernel debug a29k-nyu-kern
7090 * New remote interfaces
7096 *** Changes in GDB-4.0:
7100 Wide output is wrapped at good places to make the output more readable.
7102 Gdb now supports cross-debugging from a host machine of one type to a
7103 target machine of another type. Communication with the target system
7104 is over serial lines. The ``target'' command handles connecting to the
7105 remote system; the ``load'' command will download a program into the
7106 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7107 also supports debugging of realtime processes running under VxWorks,
7108 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7109 stub on the target system.
7111 New CPUs supported include the AMD 29000 and Intel 960.
7113 GDB now reads object files and symbol tables via a ``binary file''
7114 library, which allows a single copy of GDB to debug programs of multiple
7115 object file types such as a.out and coff.
7117 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7118 refcard.dvi and refcard.ps are available to format it).
7121 * Control-Variable user interface simplified
7123 All variables that control the operation of the debugger can be set
7124 by the ``set'' command, and displayed by the ``show'' command.
7126 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7127 ``Show prompt'' produces the response:
7128 Gdb's prompt is new-gdb=>.
7130 What follows are the NEW set commands. The command ``help set'' will
7131 print a complete list of old and new set commands. ``help set FOO''
7132 will give a longer description of the variable FOO. ``show'' will show
7133 all of the variable descriptions and their current settings.
7135 confirm on/off: Enables warning questions for operations that are
7136 hard to recover from, e.g. rerunning the program while
7137 it is already running. Default is ON.
7139 editing on/off: Enables EMACS style command line editing
7140 of input. Previous lines can be recalled with
7141 control-P, the current line can be edited with control-B,
7142 you can search for commands with control-R, etc.
7145 history filename NAME: NAME is where the gdb command history
7146 will be stored. The default is .gdb_history,
7147 or the value of the environment variable
7150 history size N: The size, in commands, of the command history. The
7151 default is 256, or the value of the environment variable
7154 history save on/off: If this value is set to ON, the history file will
7155 be saved after exiting gdb. If set to OFF, the
7156 file will not be saved. The default is OFF.
7158 history expansion on/off: If this value is set to ON, then csh-like
7159 history expansion will be performed on
7160 command line input. The default is OFF.
7162 radix N: Sets the default radix for input and output. It can be set
7163 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7164 in the current radix, so "set radix 10" is always a no-op.
7166 height N: This integer value is the number of lines on a page. Default
7167 is 24, the current `stty rows'' setting, or the ``li#''
7168 setting from the termcap entry matching the environment
7171 width N: This integer value is the number of characters on a line.
7172 Default is 80, the current `stty cols'' setting, or the ``co#''
7173 setting from the termcap entry matching the environment
7176 Note: ``set screensize'' is obsolete. Use ``set height'' and
7177 ``set width'' instead.
7179 print address on/off: Print memory addresses in various command displays,
7180 such as stack traces and structure values. Gdb looks
7181 more ``symbolic'' if you turn this off; it looks more
7182 ``machine level'' with it on. Default is ON.
7184 print array on/off: Prettyprint arrays. New convenient format! Default
7187 print demangle on/off: Print C++ symbols in "source" form if on,
7190 print asm-demangle on/off: Same, for assembler level printouts
7193 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7196 * Support for Epoch Environment.
7198 The epoch environment is a version of Emacs v18 with windowing. One
7199 new command, ``inspect'', is identical to ``print'', except that if you
7200 are running in the epoch environment, the value is printed in its own
7204 * Support for Shared Libraries
7206 GDB can now debug programs and core files that use SunOS shared libraries.
7207 Symbols from a shared library cannot be referenced
7208 before the shared library has been linked with the program (this
7209 happens after you type ``run'' and before the function main() is entered).
7210 At any time after this linking (including when examining core files
7211 from dynamically linked programs), gdb reads the symbols from each
7212 shared library when you type the ``sharedlibrary'' command.
7213 It can be abbreviated ``share''.
7215 sharedlibrary REGEXP: Load shared object library symbols for files
7216 matching a unix regular expression. No argument
7217 indicates to load symbols for all shared libraries.
7219 info sharedlibrary: Status of loaded shared libraries.
7224 A watchpoint stops execution of a program whenever the value of an
7225 expression changes. Checking for this slows down execution
7226 tremendously whenever you are in the scope of the expression, but is
7227 quite useful for catching tough ``bit-spreader'' or pointer misuse
7228 problems. Some machines such as the 386 have hardware for doing this
7229 more quickly, and future versions of gdb will use this hardware.
7231 watch EXP: Set a watchpoint (breakpoint) for an expression.
7233 info watchpoints: Information about your watchpoints.
7235 delete N: Deletes watchpoint number N (same as breakpoints).
7236 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7237 enable N: Re-enables watchpoint number N (same as breakpoints).
7240 * C++ multiple inheritance
7242 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7245 * C++ exception handling
7247 Gdb now supports limited C++ exception handling. Besides the existing
7248 ability to breakpoint on an exception handler, gdb can breakpoint on
7249 the raising of an exception (before the stack is peeled back to the
7252 catch FOO: If there is a FOO exception handler in the dynamic scope,
7253 set a breakpoint to catch exceptions which may be raised there.
7254 Multiple exceptions (``catch foo bar baz'') may be caught.
7256 info catch: Lists all exceptions which may be caught in the
7257 current stack frame.
7260 * Minor command changes
7262 The command ``call func (arg, arg, ...)'' now acts like the print
7263 command, except it does not print or save a value if the function's result
7264 is void. This is similar to dbx usage.
7266 The ``up'' and ``down'' commands now always print the frame they end up
7267 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7268 frames without printing.
7270 * New directory command
7272 'dir' now adds directories to the FRONT of the source search path.
7273 The path starts off empty. Source files that contain debug information
7274 about the directory in which they were compiled can be found even
7275 with an empty path; Sun CC and GCC include this information. If GDB can't
7276 find your source file in the current directory, type "dir .".
7278 * Configuring GDB for compilation
7280 For normal use, type ``./configure host''. See README or gdb.texinfo
7283 GDB now handles cross debugging. If you are remotely debugging between
7284 two different machines, type ``./configure host -target=targ''.
7285 Host is the machine where GDB will run; targ is the machine
7286 where the program that you are debugging will run.