1 What has changed in GDB?
2 (Organized release by release)
6 * GDB and GDBserver now support access to additional registers on
7 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
10 * GDB now has experimental support for the compilation and injection of
11 C++ source code into the inferior. This beta release does not include
12 support for several language features, such as templates, constructors,
15 This feature requires GCC 7.1 or higher built with libcp1.so
18 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
19 can be passed using the '[ADDRESS]:PORT' notation, or the regular
20 'ADDRESS:PORT' method.
22 * DWARF index cache: GDB can now automatically save indices of DWARF
23 symbols on disk to speed up further loading of the same binaries.
25 * Ada task switching is now supported on aarch64-elf targets when
26 debugging a program using the Ravenscar Profile. For more information,
27 see the "Tasking Support when using the Ravenscar Profile" section
28 in the GDB user manual.
30 * GDB in batch mode now exits with status 1 if the last command to be
33 * The RISC-V target now supports target descriptions.
35 * System call catchpoints now support system call aliases on FreeBSD.
36 When the ABI of a system call changes in FreeBSD, this is
37 implemented by leaving a compatibility system call using the old ABI
38 at the existing number and allocating a new system call number for
39 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
40 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
41 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
42 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
43 so that a system call catchpoint for the 'kevent' system call will
44 catch invocations of both the 'kevent' and 'freebsd11_kevent'
45 binaries. This ensures that 'kevent' system calls are caught for
46 binaries using either the old or new ABIs.
48 * Terminal styling is now available for the CLI and the TUI. GNU
49 Source Highlight can additionally be used to provide styling of
50 source code snippets. See the "set style" commands, below, for more
53 * Removed support for old demangling styles arm, edg, gnu, hp and
59 GNU/Linux/OpenRISC or1k*-*-linux*
63 set debug compile-cplus-types
64 show debug compile-cplus-types
65 Control the display of debug output about type conversion in the
66 C++ compile feature. Commands have no effect while compiliong
71 Control whether debug output about files/functions skipping is
74 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
75 Apply a command to some frames.
76 FLAG arguments allow to control what output to produce and how to handle
77 errors raised when applying COMMAND to a frame.
80 Apply a command to all threads (ignoring errors and empty output).
81 Shortcut for 'thread apply all -s COMMAND'.
84 Apply a command to all frames (ignoring errors and empty output).
85 Shortcut for 'frame apply all -s COMMAND'.
88 Apply a command to all frames of all threads (ignoring errors and empty
90 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
92 maint set dwarf unwinders (on|off)
93 maint show dwarf unwinders
94 Control whether DWARF unwinders can be used.
97 Display a list of open files for a process.
101 Changes to the "frame", "select-frame", and "info frame" CLI commands.
102 These commands all now take a frame specification which
103 is either a frame level, or one of the keywords 'level', 'address',
104 'function', or 'view' followed by a parameter. Selecting a frame by
105 address, or viewing a frame outside the current backtrace now
106 requires the use of a keyword. Selecting a frame by level is
107 unchanged. The MI comment "-stack-select-frame" is unchanged.
109 target remote FILENAME
110 target extended-remote FILENAME
111 If FILENAME is a Unix domain socket, GDB will attempt to connect
112 to this socket instead of opening FILENAME as a character device.
114 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
115 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
116 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
117 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
118 These commands can now print only the searched entities
119 matching the provided regexp(s), giving a condition
120 on the entity names or entity types. The flag -q disables
121 printing headers or informations messages.
127 These commands now determine the syntax for the shown entities
128 according to the language chosen by `set language'. In particular,
129 `set language auto' means to automatically choose the language of
132 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
133 The 'thread apply' command accepts new FLAG arguments.
134 FLAG arguments allow to control what output to produce and how to handle
135 errors raised when applying COMMAND to a thread.
137 set tui tab-width NCHARS
138 show tui tab-width NCHARS
139 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
141 set style enabled [on|off]
143 Enable or disable terminal styling. Styling is enabled by default
144 on most hosts, but disabled by default when in batch mode.
146 set style sources [on|off]
148 Enable or disable source code styling. Source code styling is
149 enabled by default, but only takes effect if styling in general is
150 enabled, and if GDB was linked with GNU Source Highlight.
152 set style filename foreground COLOR
153 set style filename background COLOR
154 set style filename intensity VALUE
155 Control the styling of file names.
157 set style function foreground COLOR
158 set style function background COLOR
159 set style function intensity VALUE
160 Control the styling of function names.
162 set style variable foreground COLOR
163 set style variable background COLOR
164 set style variable intensity VALUE
165 Control the styling of variable names.
167 set style address foreground COLOR
168 set style address background COLOR
169 set style address intensity VALUE
170 Control the styling of addresses.
174 ** The '-data-disassemble' MI command now accepts an '-a' option to
175 disassemble the whole function surrounding the given program
176 counter value or function name. Support for this feature can be
177 verified by using the "-list-features" command, which should
178 contain "data-disassemble-a-option".
180 ** Command responses and notifications that include a frame now include
181 the frame's architecture in a new "arch" attribute.
183 * New native configurations
185 GNU/Linux/RISC-V riscv*-*-linux*
186 FreeBSD/riscv riscv*-*-freebsd*
190 GNU/Linux/RISC-V riscv*-*-linux*
192 CSKY GNU/LINUX csky*-*-linux
193 FreeBSD/riscv riscv*-*-freebsd*
197 GDB no longer supports native debugging on versions of MS-Windows
202 ** GDB no longer supports Python versions less than 2.6.
204 ** The gdb.Inferior type has a new 'progspace' property, which is the program
205 space associated to that inferior.
207 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
208 of objfiles associated to that program space.
210 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
211 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
214 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
215 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
216 correct and did not work properly.
218 ** The gdb.Value type has a new constructor, which is used to construct a
219 gdb.Value from a Python buffer object and a gdb.Type.
225 Enable or disable the undefined behavior sanitizer. This is
226 disabled by default, but passing --enable-ubsan=yes or
227 --enable-ubsan=auto to configure will enable it. Enabling this can
228 cause a performance penalty. The undefined behavior sanitizer was
229 first introduced in GCC 4.9.
231 *** Changes in GDB 8.2
233 * The 'set disassembler-options' command now supports specifying options
236 * The 'symbol-file' command now accepts an '-o' option to add a relative
237 offset to all sections.
239 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
240 a relative offset to all sections, but it allows to override the load
241 address of individual sections using '-s'.
243 * The 'add-symbol-file' command no longer requires the second argument
244 (address of the text section).
246 * The endianness used with the 'set endian auto' mode in the absence of
247 an executable selected for debugging is now the last endianness chosen
248 either by one of the 'set endian big' and 'set endian little' commands
249 or by inferring from the last executable used, rather than the startup
252 * The pager now allows a "c" response, meaning to disable the pager
253 for the rest of the current command.
255 * The commands 'info variables/functions/types' now show the source line
256 numbers of symbol definitions when available.
258 * 'info proc' now works on running processes on FreeBSD systems and core
259 files created on FreeBSD systems.
261 * C expressions can now use _Alignof, and C++ expressions can now use
264 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
265 the vector length while the process is running.
271 Control display of debugging info regarding the FreeBSD native target.
273 set|show varsize-limit
274 This new setting allows the user to control the maximum size of Ada
275 objects being printed when those objects have a variable type,
276 instead of that maximum size being hardcoded to 65536 bytes.
278 set|show record btrace cpu
279 Controls the processor to be used for enabling errata workarounds for
282 maint check libthread-db
283 Run integrity checks on the current inferior's thread debugging
286 maint set check-libthread-db (on|off)
287 maint show check-libthread-db
288 Control whether to run integrity checks on inferior specific thread
289 debugging libraries as they are loaded. The default is not to
294 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
296 ** The commands attached to a breakpoint can be set by assigning to
297 the breakpoint's "commands" field.
299 ** gdb.execute can now execute multi-line gdb commands.
301 ** The new functions gdb.convenience_variable and
302 gdb.set_convenience_variable can be used to get and set the value
303 of convenience variables.
305 ** A gdb.Parameter will no longer print the "set" help text on an
306 ordinary "set"; instead by default a "set" will be silent unless
307 the get_set_string method returns a non-empty string.
311 RiscV ELF riscv*-*-elf
313 * Removed targets and native configurations
315 m88k running OpenBSD m88*-*-openbsd*
316 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
317 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
318 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
320 * Aarch64/Linux hardware watchpoints improvements
322 Hardware watchpoints on unaligned addresses are now properly
323 supported when running Linux kernel 4.10 or higher: read and access
324 watchpoints are no longer spuriously missed, and all watchpoints
325 lengths between 1 and 8 bytes are supported. On older kernels,
326 watchpoints set on unaligned addresses are no longer missed, with
327 the tradeoff that there is a possibility of false hits being
332 --enable-codesign=CERT
333 This can be used to invoke "codesign -s CERT" after building gdb.
334 This option is useful on macOS, where code signing is required for
335 gdb to work properly.
337 --disable-gdbcli has been removed
338 This is now silently accepted, but does nothing.
340 *** Changes in GDB 8.1
342 * GDB now supports dynamically creating arbitrary register groups specified
343 in XML target descriptions. This allows for finer grain grouping of
344 registers on systems with a large amount of registers.
346 * The 'ptype' command now accepts a '/o' flag, which prints the
347 offsets and sizes of fields in a struct, like the pahole(1) tool.
349 * New "--readnever" command line option instructs GDB to not read each
350 symbol file's symbolic debug information. This makes startup faster
351 but at the expense of not being able to perform symbolic debugging.
352 This option is intended for use cases where symbolic debugging will
353 not be used, e.g., when you only need to dump the debuggee's core.
355 * GDB now uses the GNU MPFR library, if available, to emulate target
356 floating-point arithmetic during expression evaluation when the target
357 uses different floating-point formats than the host. At least version
358 3.1 of GNU MPFR is required.
360 * GDB now supports access to the guarded-storage-control registers and the
361 software-based guarded-storage broadcast control registers on IBM z14.
363 * On Unix systems, GDB now supports transmitting environment variables
364 that are to be set or unset to GDBserver. These variables will
365 affect the environment to be passed to the remote inferior.
367 To inform GDB of environment variables that are to be transmitted to
368 GDBserver, use the "set environment" command. Only user set
369 environment variables are sent to GDBserver.
371 To inform GDB of environment variables that are to be unset before
372 the remote inferior is started by the GDBserver, use the "unset
373 environment" command.
375 * Completion improvements
377 ** GDB can now complete function parameters in linespecs and
378 explicit locations without quoting. When setting breakpoints,
379 quoting around functions names to help with TAB-completion is
380 generally no longer necessary. For example, this now completes
383 (gdb) b function(in[TAB]
384 (gdb) b function(int)
386 Related, GDB is no longer confused with completing functions in
387 C++ anonymous namespaces:
390 (gdb) b (anonymous namespace)::[TAB][TAB]
391 (anonymous namespace)::a_function()
392 (anonymous namespace)::b_function()
394 ** GDB now has much improved linespec and explicit locations TAB
395 completion support, that better understands what you're
396 completing and offers better suggestions. For example, GDB no
397 longer offers data symbols as possible completions when you're
398 setting a breakpoint.
400 ** GDB now TAB-completes label symbol names.
402 ** The "complete" command now mimics TAB completion accurately.
404 * New command line options (gcore)
407 Dump all memory mappings.
409 * Breakpoints on C++ functions are now set on all scopes by default
411 By default, breakpoints on functions/methods are now interpreted as
412 specifying all functions with the given name ignoring missing
413 leading scopes (namespaces and classes).
415 For example, assuming a C++ program with symbols named:
420 both commands "break func()" and "break B::func()" set a breakpoint
423 You can use the new flag "-qualified" to override this. This makes
424 GDB interpret the specified function name as a complete
425 fully-qualified name instead. For example, using the same C++
426 program, the "break -q B::func" command sets a breakpoint on
427 "B::func", only. A parameter has been added to the Python
428 gdb.Breakpoint constructor to achieve the same result when creating
429 a breakpoint from Python.
431 * Breakpoints on functions marked with C++ ABI tags
433 GDB can now set breakpoints on functions marked with C++ ABI tags
434 (e.g., [abi:cxx11]). See here for a description of ABI tags:
435 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
437 Functions with a C++11 abi tag are demangled/displayed like this:
439 function[abi:cxx11](int)
442 You can now set a breakpoint on such functions simply as if they had
445 (gdb) b function(int)
447 Or if you need to disambiguate between tags, like:
449 (gdb) b function[abi:other_tag](int)
451 Tab completion was adjusted accordingly as well.
455 ** New events gdb.new_inferior, gdb.inferior_deleted, and
456 gdb.new_thread are emitted. See the manual for further
457 description of these.
459 ** A new function, "gdb.rbreak" has been added to the Python API.
460 This function allows the setting of a large number of breakpoints
461 via a regex pattern in Python. See the manual for further details.
463 ** Python breakpoints can now accept explicit locations. See the
464 manual for a further description of this feature.
467 * New features in the GDB remote stub, GDBserver
469 ** GDBserver is now able to start inferior processes with a
470 specified initial working directory.
472 The user can set the desired working directory to be used from
473 GDB using the new "set cwd" command.
475 ** New "--selftest" command line option runs some GDBserver self
476 tests. These self tests are disabled in releases.
478 ** On Unix systems, GDBserver now does globbing expansion and variable
479 substitution in inferior command line arguments.
481 This is done by starting inferiors using a shell, like GDB does.
482 See "set startup-with-shell" in the user manual for how to disable
483 this from GDB when using "target extended-remote". When using
484 "target remote", you can disable the startup with shell by using the
485 new "--no-startup-with-shell" GDBserver command line option.
487 ** On Unix systems, GDBserver now supports receiving environment
488 variables that are to be set or unset from GDB. These variables
489 will affect the environment to be passed to the inferior.
491 * When catching an Ada exception raised with a message, GDB now prints
492 the message in the catchpoint hit notification. In GDB/MI mode, that
493 information is provided as an extra field named "exception-message"
494 in the *stopped notification.
496 * Trait objects can now be inspected When debugging Rust code. This
497 requires compiler support which will appear in Rust 1.24.
501 QEnvironmentHexEncoded
502 Inform GDBserver of an environment variable that is to be passed to
503 the inferior when starting it.
506 Inform GDBserver of an environment variable that is to be unset
507 before starting the remote inferior.
510 Inform GDBserver that the environment should be reset (i.e.,
511 user-set environment variables should be unset).
514 Indicates whether the inferior must be started with a shell or not.
517 Tell GDBserver that the inferior to be started should use a specific
520 * The "maintenance print c-tdesc" command now takes an optional
521 argument which is the file name of XML target description.
523 * The "maintenance selftest" command now takes an optional argument to
524 filter the tests to be run.
526 * The "enable", and "disable" commands now accept a range of
527 breakpoint locations, e.g. "enable 1.3-5".
532 Set and show the current working directory for the inferior.
535 Set and show compilation command used for compiling and injecting code
536 with the 'compile' commands.
538 set debug separate-debug-file
539 show debug separate-debug-file
540 Control the display of debug output about separate debug file search.
542 set dump-excluded-mappings
543 show dump-excluded-mappings
544 Control whether mappings marked with the VM_DONTDUMP flag should be
545 dumped when generating a core file.
548 List the registered selftests.
551 Start the debugged program stopping at the first instruction.
554 Control display of debugging messages related to OpenRISC targets.
556 set|show print type nested-type-limit
557 Set and show the limit of nesting level for nested types that the
558 type printer will show.
560 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
563 * Safer/improved support for debugging with no debug info
565 GDB no longer assumes functions with no debug information return
568 This means that GDB now refuses to call such functions unless you
569 tell it the function's type, by either casting the call to the
570 declared return type, or by casting the function to a function
571 pointer of the right type, and calling that:
573 (gdb) p getenv ("PATH")
574 'getenv' has unknown return type; cast the call to its declared return type
575 (gdb) p (char *) getenv ("PATH")
576 $1 = 0x7fffffffe "/usr/local/bin:/"...
577 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
578 $2 = 0x7fffffffe "/usr/local/bin:/"...
580 Similarly, GDB no longer assumes that global variables with no debug
581 info have type 'int', and refuses to print the variable's value
582 unless you tell it the variable's type:
585 'var' has unknown type; cast it to its declared type
589 * New native configurations
591 FreeBSD/aarch64 aarch64*-*-freebsd*
592 FreeBSD/arm arm*-*-freebsd*
596 FreeBSD/aarch64 aarch64*-*-freebsd*
597 FreeBSD/arm arm*-*-freebsd*
598 OpenRISC ELF or1k*-*-elf
600 * Removed targets and native configurations
602 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
604 *** Changes in GDB 8.0
606 * GDB now supports access to the PKU register on GNU/Linux. The register is
607 added by the Memory Protection Keys for Userspace feature which will be
608 available in future Intel CPUs.
610 * GDB now supports C++11 rvalue references.
614 ** New functions to start, stop and access a running btrace recording.
615 ** Rvalue references are now supported in gdb.Type.
617 * GDB now supports recording and replaying rdrand and rdseed Intel 64
620 * Building GDB and GDBserver now requires a C++11 compiler.
622 For example, GCC 4.8 or later.
624 It is no longer possible to build GDB or GDBserver with a C
625 compiler. The --disable-build-with-cxx configure option has been
628 * Building GDB and GDBserver now requires GNU make >= 3.81.
630 It is no longer supported to build GDB or GDBserver with another
631 implementation of the make program or an earlier version of GNU make.
633 * Native debugging on MS-Windows supports command-line redirection
635 Command-line arguments used for starting programs on MS-Windows can
636 now include redirection symbols supported by native Windows shells,
637 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
638 as "run", "start", and "set args", as well as the corresponding MI
641 * Support for thread names on MS-Windows.
643 GDB now catches and handles the special exception that programs
644 running on MS-Windows use to assign names to threads in the
647 * Support for Java programs compiled with gcj has been removed.
649 * User commands now accept an unlimited number of arguments.
650 Previously, only up to 10 was accepted.
652 * The "eval" command now expands user-defined command arguments.
654 This makes it easier to process a variable number of arguments:
659 eval "print $arg%d", $i
664 * Target descriptions can now describe registers for sparc32 and sparc64.
666 * GDB now supports DWARF version 5 (debug information format).
667 Its .debug_names index is not yet supported.
669 * New native configurations
671 FreeBSD/mips mips*-*-freebsd
675 Synopsys ARC arc*-*-elf32
676 FreeBSD/mips mips*-*-freebsd
678 * Removed targets and native configurations
680 Alpha running FreeBSD alpha*-*-freebsd*
681 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
686 Erases all the flash memory regions reported by the target.
688 maint print arc arc-instruction address
689 Print internal disassembler information about instruction at a given address.
693 set disassembler-options
694 show disassembler-options
695 Controls the passing of target specific information to the disassembler.
696 If it is necessary to specify more than one disassembler option then
697 multiple options can be placed together into a comma separated list.
698 The default value is the empty string. Currently, the only supported
699 targets are ARM, PowerPC and S/390.
704 Erases all the flash memory regions reported by the target. This is
705 equivalent to the CLI command flash-erase.
707 -file-list-shared-libraries
708 List the shared libraries in the program. This is
709 equivalent to the CLI command "info shared".
712 Catchpoints stopping the program when Ada exceptions are
713 handled. This is equivalent to the CLI command "catch handlers".
715 *** Changes in GDB 7.12
717 * GDB and GDBserver now build with a C++ compiler by default.
719 The --enable-build-with-cxx configure option is now enabled by
720 default. One must now explicitly configure with
721 --disable-build-with-cxx in order to build with a C compiler. This
722 option will be removed in a future release.
724 * GDBserver now supports recording btrace without maintaining an active
727 * GDB now supports a negative repeat count in the 'x' command to examine
728 memory backward from the given address. For example:
731 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
732 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
733 (gdb) x/-5i 0x0000000000400580
734 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
735 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
736 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
737 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
738 0x40057b <main(int, char**)+25>:
739 callq 0x400536 <Func1(int, char const*)>
741 * Fortran: Support structures with fields of dynamic types and
742 arrays of dynamic types.
744 * The symbol dumping maintenance commands have new syntax.
745 maint print symbols [-pc address] [--] [filename]
746 maint print symbols [-objfile objfile] [-source source] [--] [filename]
747 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
748 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
749 maint print msymbols [-objfile objfile] [--] [filename]
751 * GDB now supports multibit bitfields and enums in target register
754 * New Python-based convenience function $_as_string(val), which returns
755 the textual representation of a value. This function is especially
756 useful to obtain the text label of an enum value.
758 * Intel MPX bound violation handling.
760 Segmentation faults caused by a Intel MPX boundary violation
761 now display the kind of violation (upper or lower), the memory
762 address accessed and the memory bounds, along with the usual
763 signal received and code location.
767 Program received signal SIGSEGV, Segmentation fault
768 Upper bound violation while accessing address 0x7fffffffc3b3
769 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
770 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
772 * Rust language support.
773 GDB now supports debugging programs written in the Rust programming
774 language. See https://www.rust-lang.org/ for more information about
777 * Support for running interpreters on specified input/output devices
779 GDB now supports a new mechanism that allows frontends to provide
780 fully featured GDB console views, as a better alternative to
781 building such views on top of the "-interpreter-exec console"
782 command. See the new "new-ui" command below. With that command,
783 frontends can now start GDB in the traditional command-line mode
784 running in an embedded terminal emulator widget, and create a
785 separate MI interpreter running on a specified i/o device. In this
786 way, GDB handles line editing, history, tab completion, etc. in the
787 console all by itself, and the GUI uses the separate MI interpreter
788 for its own control and synchronization, invisible to the command
791 * The "catch syscall" command catches groups of related syscalls.
793 The "catch syscall" command now supports catching a group of related
794 syscalls using the 'group:' or 'g:' prefix.
799 skip -gfile file-glob-pattern
800 skip -function function
801 skip -rfunction regular-expression
802 A generalized form of the skip command, with new support for
803 glob-style file names and regular expressions for function names.
804 Additionally, a file spec and a function spec may now be combined.
806 maint info line-table REGEXP
807 Display the contents of GDB's internal line table data struture.
810 Run any GDB unit tests that were compiled in.
813 Start a new user interface instance running INTERP as interpreter,
814 using the TTY file for input/output.
818 ** gdb.Breakpoint objects have a new attribute "pending", which
819 indicates whether the breakpoint is pending.
820 ** Three new breakpoint-related events have been added:
821 gdb.breakpoint_created, gdb.breakpoint_modified, and
822 gdb.breakpoint_deleted.
825 Signal ("set") the given MS-Windows event object. This is used in
826 conjunction with the Windows JIT debugging (AeDebug) support, where
827 the OS suspends a crashing process until a debugger can attach to
828 it. Resuming the crashing process, in order to debug it, is done by
831 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
832 was added in GDBserver, including JIT compiling fast tracepoint's
833 conditional expression bytecode into native code.
835 * Support for various remote target protocols and ROM monitors has
838 target m32rsdi Remote M32R debugging over SDI
839 target mips MIPS remote debugging protocol
840 target pmon PMON ROM monitor
841 target ddb NEC's DDB variant of PMON for Vr4300
842 target rockhopper NEC RockHopper variant of PMON
843 target lsi LSI variant of PMO
845 * Support for tracepoints and fast tracepoints on powerpc-linux,
846 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
847 including JIT compiling fast tracepoint's conditional expression
848 bytecode into native code.
850 * MI async record =record-started now includes the method and format used for
851 recording. For example:
853 =record-started,thread-group="i1",method="btrace",format="bts"
855 * MI async record =thread-selected now includes the frame field. For example:
857 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
861 Andes NDS32 nds32*-*-elf
863 *** Changes in GDB 7.11
865 * GDB now supports debugging kernel-based threads on FreeBSD.
867 * Per-inferior thread numbers
869 Thread numbers are now per inferior instead of global. If you're
870 debugging multiple inferiors, GDB displays thread IDs using a
871 qualified INF_NUM.THR_NUM form. For example:
875 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
876 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
877 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
878 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
880 As consequence, thread numbers as visible in the $_thread
881 convenience variable and in Python's InferiorThread.num attribute
882 are no longer unique between inferiors.
884 GDB now maintains a second thread ID per thread, referred to as the
885 global thread ID, which is the new equivalent of thread numbers in
886 previous releases. See also $_gthread below.
888 For backwards compatibility, MI's thread IDs always refer to global
891 * Commands that accept thread IDs now accept the qualified
892 INF_NUM.THR_NUM form as well. For example:
895 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
898 * In commands that accept a list of thread IDs, you can now refer to
899 all threads of an inferior using a star wildcard. GDB accepts
900 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
901 refer to all threads of the current inferior. For example, "info
904 * You can use "info threads -gid" to display the global thread ID of
907 * The new convenience variable $_gthread holds the global number of
910 * The new convenience variable $_inferior holds the number of the
913 * GDB now displays the ID and name of the thread that hit a breakpoint
914 or received a signal, if your program is multi-threaded. For
917 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
918 Thread 1 "main" received signal SIGINT, Interrupt.
920 * Record btrace now supports non-stop mode.
922 * Support for tracepoints on aarch64-linux was added in GDBserver.
924 * The 'record instruction-history' command now indicates speculative execution
925 when using the Intel Processor Trace recording format.
927 * GDB now allows users to specify explicit locations, bypassing
928 the linespec parser. This feature is also available to GDB/MI
931 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
932 GDB now is able to debug both AArch64 applications and ARM applications
935 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
936 including JIT compiling fast tracepoint's conditional expression bytecode
939 * GDB now supports displaced stepping on AArch64 GNU/Linux.
941 * "info threads", "info inferiors", "info display", "info checkpoints"
942 and "maint info program-spaces" now list the corresponding items in
943 ascending ID order, for consistency with all other "info" commands.
945 * In Ada, the overloads selection menu has been enhanced to display the
946 parameter types and the return types for the matching overloaded subprograms.
950 maint set target-non-stop (on|off|auto)
951 maint show target-non-stop
952 Control whether GDB targets always operate in non-stop mode even if
953 "set non-stop" is "off". The default is "auto", meaning non-stop
954 mode is enabled if supported by the target.
956 maint set bfd-sharing
957 maint show bfd-sharing
958 Control the reuse of bfd objects.
962 Control display of debugging info regarding bfd caching.
966 Control display of debugging info regarding FreeBSD threads.
968 set remote multiprocess-extensions-packet
969 show remote multiprocess-extensions-packet
970 Set/show the use of the remote protocol multiprocess extensions.
972 set remote thread-events
973 show remote thread-events
974 Set/show the use of thread create/exit events.
976 set ada print-signatures on|off
977 show ada print-signatures"
978 Control whether parameter types and return types are displayed in overloads
979 selection menus. It is activaled (@code{on}) by default.
983 Controls the maximum size of memory, in bytes, that GDB will
984 allocate for value contents. Prevents incorrect programs from
985 causing GDB to allocate overly large buffers. Default is 64k.
987 * The "disassemble" command accepts a new modifier: /s.
988 It prints mixed source+disassembly like /m with two differences:
989 - disassembled instructions are now printed in program order, and
990 - and source for all relevant files is now printed.
991 The "/m" option is now considered deprecated: its "source-centric"
992 output hasn't proved useful in practice.
994 * The "record instruction-history" command accepts a new modifier: /s.
995 It behaves exactly like /m and prints mixed source+disassembly.
997 * The "set scheduler-locking" command supports a new mode "replay".
998 It behaves like "off" in record mode and like "on" in replay mode.
1000 * Support for various ROM monitors has been removed:
1002 target dbug dBUG ROM monitor for Motorola ColdFire
1003 target picobug Motorola picobug monitor
1004 target dink32 DINK32 ROM monitor for PowerPC
1005 target m32r Renesas M32R/D ROM monitor
1006 target mon2000 mon2000 ROM monitor
1007 target ppcbug PPCBUG ROM monitor for PowerPC
1009 * Support for reading/writing memory and extracting values on architectures
1010 whose memory is addressable in units of any integral multiple of 8 bits.
1013 Allows to break when an Ada exception is handled.
1015 * New remote packets
1018 Indicates that an exec system call was executed.
1020 exec-events feature in qSupported
1021 The qSupported packet allows GDB to request support for exec
1022 events using the new 'gdbfeature' exec-event, and the qSupported
1023 response can contain the corresponding 'stubfeature'. Set and
1024 show commands can be used to display whether these features are enabled.
1027 Equivalent to interrupting with the ^C character, but works in
1030 thread created stop reason (T05 create:...)
1031 Indicates that the thread was just created and is stopped at entry.
1033 thread exit stop reply (w exitcode;tid)
1034 Indicates that the thread has terminated.
1037 Enables/disables thread create and exit event reporting. For
1038 example, this is used in non-stop mode when GDB stops a set of
1039 threads and synchronously waits for the their corresponding stop
1040 replies. Without exit events, if one of the threads exits, GDB
1041 would hang forever not knowing that it should no longer expect a
1042 stop for that same thread.
1045 Indicates that there are no resumed threads left in the target (all
1046 threads are stopped). The remote stub reports support for this stop
1047 reply to GDB's qSupported query.
1050 Enables/disables catching syscalls from the inferior process.
1051 The remote stub reports support for this packet to GDB's qSupported query.
1053 syscall_entry stop reason
1054 Indicates that a syscall was just called.
1056 syscall_return stop reason
1057 Indicates that a syscall just returned.
1059 * Extended-remote exec events
1061 ** GDB now has support for exec events on extended-remote Linux targets.
1062 For such targets with Linux kernels 2.5.46 and later, this enables
1063 follow-exec-mode and exec catchpoints.
1065 set remote exec-event-feature-packet
1066 show remote exec-event-feature-packet
1067 Set/show the use of the remote exec event feature.
1069 * Thread names in remote protocol
1071 The reply to qXfer:threads:read may now include a name attribute for each
1074 * Target remote mode fork and exec events
1076 ** GDB now has support for fork and exec events on target remote mode
1077 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1078 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1079 fork and exec catchpoints.
1081 * Remote syscall events
1083 ** GDB now has support for catch syscall on remote Linux targets,
1084 currently enabled on x86/x86_64 architectures.
1086 set remote catch-syscall-packet
1087 show remote catch-syscall-packet
1088 Set/show the use of the remote catch syscall feature.
1092 ** The -var-set-format command now accepts the zero-hexadecimal
1093 format. It outputs data in hexadecimal format with zero-padding on the
1098 ** gdb.InferiorThread objects have a new attribute "global_num",
1099 which refers to the thread's global thread ID. The existing
1100 "num" attribute now refers to the thread's per-inferior number.
1101 See "Per-inferior thread numbers" above.
1102 ** gdb.InferiorThread objects have a new attribute "inferior", which
1103 is the Inferior object the thread belongs to.
1105 *** Changes in GDB 7.10
1107 * Support for process record-replay and reverse debugging on aarch64*-linux*
1108 targets has been added. GDB now supports recording of A64 instruction set
1109 including advance SIMD instructions.
1111 * Support for Sun's version of the "stabs" debug file format has been removed.
1113 * GDB now honors the content of the file /proc/PID/coredump_filter
1114 (PID is the process ID) on GNU/Linux systems. This file can be used
1115 to specify the types of memory mappings that will be included in a
1116 corefile. For more information, please refer to the manual page of
1117 "core(5)". GDB also has a new command: "set use-coredump-filter
1118 on|off". It allows to set whether GDB will read the content of the
1119 /proc/PID/coredump_filter file when generating a corefile.
1121 * The "info os" command on GNU/Linux can now display information on
1123 "info os cpus" Listing of all cpus/cores on the system
1125 * GDB has two new commands: "set serial parity odd|even|none" and
1126 "show serial parity". These allows to set or show parity for the
1129 * The "info source" command now displays the producer string if it was
1130 present in the debug info. This typically includes the compiler version
1131 and may include things like its command line arguments.
1133 * The "info dll", an alias of the "info sharedlibrary" command,
1134 is now available on all platforms.
1136 * Directory names supplied to the "set sysroot" commands may be
1137 prefixed with "target:" to tell GDB to access shared libraries from
1138 the target system, be it local or remote. This replaces the prefix
1139 "remote:". The default sysroot has been changed from "" to
1140 "target:". "remote:" is automatically converted to "target:" for
1141 backward compatibility.
1143 * The system root specified by "set sysroot" will be prepended to the
1144 filename of the main executable (if reported to GDB as absolute by
1145 the operating system) when starting processes remotely, and when
1146 attaching to already-running local or remote processes.
1148 * GDB now supports automatic location and retrieval of executable
1149 files from remote targets. Remote debugging can now be initiated
1150 using only a "target remote" or "target extended-remote" command
1151 (no "set sysroot" or "file" commands are required). See "New remote
1154 * The "dump" command now supports verilog hex format.
1156 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1158 * On GNU/Linux, GDB and gdbserver are now able to access executable
1159 and shared library files without a "set sysroot" command when
1160 attaching to processes running in different mount namespaces from
1161 the debugger. This makes it possible to attach to processes in
1162 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1163 See "New remote packets" below.
1165 * The "tui reg" command now provides completion for all of the
1166 available register groups, including target specific groups.
1168 * The HISTSIZE environment variable is no longer read when determining
1169 the size of GDB's command history. GDB now instead reads the dedicated
1170 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1171 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1176 ** Memory ports can now be unbuffered.
1180 ** gdb.Objfile objects have a new attribute "username",
1181 which is the name of the objfile as specified by the user,
1182 without, for example, resolving symlinks.
1183 ** You can now write frame unwinders in Python.
1184 ** gdb.Type objects have a new method "optimized_out",
1185 returning optimized out gdb.Value instance of this type.
1186 ** gdb.Value objects have new methods "reference_value" and
1187 "const_value" which return a reference to the value and a
1188 "const" version of the value respectively.
1192 maint print symbol-cache
1193 Print the contents of the symbol cache.
1195 maint print symbol-cache-statistics
1196 Print statistics of symbol cache usage.
1198 maint flush-symbol-cache
1199 Flush the contents of the symbol cache.
1203 Start branch trace recording using Branch Trace Store (BTS) format.
1206 Evaluate expression by using the compiler and print result.
1210 Explicit commands for enabling and disabling tui mode.
1213 set mpx bound on i386 and amd64
1214 Support for bound table investigation on Intel MPX enabled applications.
1218 Start branch trace recording using Intel Processor Trace format.
1221 Print information about branch tracing internals.
1223 maint btrace packet-history
1224 Print the raw branch tracing data.
1226 maint btrace clear-packet-history
1227 Discard the stored raw branch tracing data.
1230 Discard all branch tracing data. It will be fetched and processed
1231 anew by the next "record" command.
1236 Renamed from "set debug dwarf2-die".
1237 show debug dwarf-die
1238 Renamed from "show debug dwarf2-die".
1240 set debug dwarf-read
1241 Renamed from "set debug dwarf2-read".
1242 show debug dwarf-read
1243 Renamed from "show debug dwarf2-read".
1245 maint set dwarf always-disassemble
1246 Renamed from "maint set dwarf2 always-disassemble".
1247 maint show dwarf always-disassemble
1248 Renamed from "maint show dwarf2 always-disassemble".
1250 maint set dwarf max-cache-age
1251 Renamed from "maint set dwarf2 max-cache-age".
1252 maint show dwarf max-cache-age
1253 Renamed from "maint show dwarf2 max-cache-age".
1255 set debug dwarf-line
1256 show debug dwarf-line
1257 Control display of debugging info regarding DWARF line processing.
1260 show max-completions
1261 Set the maximum number of candidates to be considered during
1262 completion. The default value is 200. This limit allows GDB
1263 to avoid generating large completion lists, the computation of
1264 which can cause the debugger to become temporarily unresponsive.
1266 set history remove-duplicates
1267 show history remove-duplicates
1268 Control the removal of duplicate history entries.
1270 maint set symbol-cache-size
1271 maint show symbol-cache-size
1272 Control the size of the symbol cache.
1274 set|show record btrace bts buffer-size
1275 Set and show the size of the ring buffer used for branch tracing in
1277 The obtained size may differ from the requested size. Use "info
1278 record" to see the obtained buffer size.
1280 set debug linux-namespaces
1281 show debug linux-namespaces
1282 Control display of debugging info regarding Linux namespaces.
1284 set|show record btrace pt buffer-size
1285 Set and show the size of the ring buffer used for branch tracing in
1286 Intel Processor Trace format.
1287 The obtained size may differ from the requested size. Use "info
1288 record" to see the obtained buffer size.
1290 maint set|show btrace pt skip-pad
1291 Set and show whether PAD packets are skipped when computing the
1294 * The command 'thread apply all' can now support new option '-ascending'
1295 to call its specified command for all threads in ascending order.
1297 * Python/Guile scripting
1299 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1300 special section named `.debug_gdb_scripts'.
1302 * New remote packets
1304 qXfer:btrace-conf:read
1305 Return the branch trace configuration for the current thread.
1307 Qbtrace-conf:bts:size
1308 Set the requested ring buffer size for branch tracing in BTS format.
1311 Enable Intel Procesor Trace-based branch tracing for the current
1312 process. The remote stub reports support for this packet to GDB's
1315 Qbtrace-conf:pt:size
1316 Set the requested ring buffer size for branch tracing in Intel Processor
1320 Indicates a memory breakpoint instruction was executed, irrespective
1321 of whether it was GDB that planted the breakpoint or the breakpoint
1322 is hardcoded in the program. This is required for correct non-stop
1326 Indicates the target stopped for a hardware breakpoint. This is
1327 required for correct non-stop mode operation.
1330 Return information about files on the remote system.
1332 qXfer:exec-file:read
1333 Return the full absolute name of the file that was executed to
1334 create a process running on the remote system.
1337 Select the filesystem on which vFile: operations with filename
1338 arguments will operate. This is required for GDB to be able to
1339 access files on remote targets where the remote stub does not
1340 share a common filesystem with the inferior(s).
1343 Indicates that a fork system call was executed.
1346 Indicates that a vfork system call was executed.
1348 vforkdone stop reason
1349 Indicates that a vfork child of the specified process has executed
1350 an exec or exit, allowing the vfork parent to resume execution.
1352 fork-events and vfork-events features in qSupported
1353 The qSupported packet allows GDB to request support for fork and
1354 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1355 and the qSupported response can contain the corresponding
1356 'stubfeatures'. Set and show commands can be used to display
1357 whether these features are enabled.
1359 * Extended-remote fork events
1361 ** GDB now has support for fork events on extended-remote Linux
1362 targets. For targets with Linux kernels 2.5.60 and later, this
1363 enables follow-fork-mode and detach-on-fork for both fork and
1364 vfork, as well as fork and vfork catchpoints.
1366 * The info record command now shows the recording format and the
1367 branch tracing configuration for the current thread when using
1368 the btrace record target.
1369 For the BTS format, it shows the ring buffer size.
1371 * GDB now has support for DTrace USDT (Userland Static Defined
1372 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1374 * GDB now supports access to vector registers on S/390 GNU/Linux
1377 * Removed command line options
1379 -xdb HP-UX XDB compatibility mode.
1381 * Removed targets and native configurations
1383 HP/PA running HP-UX hppa*-*-hpux*
1384 Itanium running HP-UX ia64-*-hpux*
1386 * New configure options
1389 This configure option allows the user to build GDB with support for
1390 Intel Processor Trace (default: auto). This requires libipt.
1392 --with-libipt-prefix=PATH
1393 Specify the path to the version of libipt that GDB should use.
1394 $PATH/include should contain the intel-pt.h header and
1395 $PATH/lib should contain the libipt.so library.
1397 *** Changes in GDB 7.9.1
1401 ** Xmethods can now specify a result type.
1403 *** Changes in GDB 7.9
1405 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1409 ** You can now access frame registers from Python scripts.
1410 ** New attribute 'producer' for gdb.Symtab objects.
1411 ** gdb.Objfile objects have a new attribute "progspace",
1412 which is the gdb.Progspace object of the containing program space.
1413 ** gdb.Objfile objects have a new attribute "owner".
1414 ** gdb.Objfile objects have a new attribute "build_id",
1415 which is the build ID generated when the file was built.
1416 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1417 ** A new event "gdb.clear_objfiles" has been added, triggered when
1418 selecting a new file to debug.
1419 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1420 ** New function gdb.lookup_objfile.
1422 New events which are triggered when GDB modifies the state of the
1425 ** gdb.events.inferior_call_pre: Function call is about to be made.
1426 ** gdb.events.inferior_call_post: Function call has just been made.
1427 ** gdb.events.memory_changed: A memory location has been altered.
1428 ** gdb.events.register_changed: A register has been altered.
1430 * New Python-based convenience functions:
1432 ** $_caller_is(name [, number_of_frames])
1433 ** $_caller_matches(regexp [, number_of_frames])
1434 ** $_any_caller_is(name [, number_of_frames])
1435 ** $_any_caller_matches(regexp [, number_of_frames])
1437 * GDB now supports the compilation and injection of source code into
1438 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1439 to compile the source code to object code, and if successful, inject
1440 and execute that code within the current context of the inferior.
1441 Currently the C language is supported. The commands used to
1442 interface with this new feature are:
1444 compile code [-raw|-r] [--] [source code]
1445 compile file [-raw|-r] filename
1449 demangle [-l language] [--] name
1450 Demangle "name" in the specified language, or the current language
1451 if elided. This command is renamed from the "maint demangle" command.
1452 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1453 as "maint demangler-warning".
1455 queue-signal signal-name-or-number
1456 Queue a signal to be delivered to the thread when it is resumed.
1458 add-auto-load-scripts-directory directory
1459 Add entries to the list of directories from which to load auto-loaded
1462 maint print user-registers
1463 List all currently available "user" registers.
1465 compile code [-r|-raw] [--] [source code]
1466 Compile, inject, and execute in the inferior the executable object
1467 code produced by compiling the provided source code.
1469 compile file [-r|-raw] filename
1470 Compile and inject into the inferior the executable object code
1471 produced by compiling the source code stored in the filename
1474 * On resume, GDB now always passes the signal the program had stopped
1475 for to the thread the signal was sent to, even if the user changed
1476 threads before resuming. Previously GDB would often (but not
1477 always) deliver the signal to the thread that happens to be current
1480 * Conversely, the "signal" command now consistently delivers the
1481 requested signal to the current thread. GDB now asks for
1482 confirmation if the program had stopped for a signal and the user
1483 switched threads meanwhile.
1485 * "breakpoint always-inserted" modes "off" and "auto" merged.
1487 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1488 won't remove breakpoints from the target until all threads stop,
1489 even in non-stop mode. The "auto" mode has been removed, and "off"
1490 is now the default mode.
1494 set debug symbol-lookup
1495 show debug symbol-lookup
1496 Control display of debugging info regarding symbol lookup.
1500 ** The -list-thread-groups command outputs an exit-code field for
1501 inferiors that have exited.
1505 MIPS SDE mips*-sde*-elf*
1509 Support for these obsolete configurations has been removed.
1511 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1512 SGI Irix-5.x mips-*-irix5*
1513 SGI Irix-6.x mips-*-irix6*
1514 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1515 VAX running Ultrix vax-*-ultrix*
1517 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1518 and "assf"), have been removed. Use the "sharedlibrary" command, or
1519 its alias "share", instead.
1521 *** Changes in GDB 7.8
1523 * New command line options
1526 This is an alias for the --data-directory option.
1528 * GDB supports printing and modifying of variable length automatic arrays
1529 as specified in ISO C99.
1531 * The ARM simulator now supports instruction level tracing
1532 with or without disassembly.
1536 GDB now has support for scripting using Guile. Whether this is
1537 available is determined at configure time.
1538 Guile version 2.0 or greater is required.
1539 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1541 * New commands (for set/show, see "New options" below)
1545 Invoke CODE by passing it to the Guile interpreter.
1549 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1551 info auto-load guile-scripts [regexp]
1552 Print the list of automatically loaded Guile scripts.
1554 * The source command is now capable of sourcing Guile scripts.
1555 This feature is dependent on the debugger being built with Guile support.
1559 set print symbol-loading (off|brief|full)
1560 show print symbol-loading
1561 Control whether to print informational messages when loading symbol
1562 information for a file. The default is "full", but when debugging
1563 programs with large numbers of shared libraries the amount of output
1564 becomes less useful.
1566 set guile print-stack (none|message|full)
1567 show guile print-stack
1568 Show a stack trace when an error is encountered in a Guile script.
1570 set auto-load guile-scripts (on|off)
1571 show auto-load guile-scripts
1572 Control auto-loading of Guile script files.
1574 maint ada set ignore-descriptive-types (on|off)
1575 maint ada show ignore-descriptive-types
1576 Control whether the debugger should ignore descriptive types in Ada
1577 programs. The default is not to ignore the descriptive types. See
1578 the user manual for more details on descriptive types and the intended
1579 usage of this option.
1581 set auto-connect-native-target
1583 Control whether GDB is allowed to automatically connect to the
1584 native target for the run, attach, etc. commands when not connected
1585 to any target yet. See also "target native" below.
1587 set record btrace replay-memory-access (read-only|read-write)
1588 show record btrace replay-memory-access
1589 Control what memory accesses are allowed during replay.
1591 maint set target-async (on|off)
1592 maint show target-async
1593 This controls whether GDB targets operate in synchronous or
1594 asynchronous mode. Normally the default is asynchronous, if it is
1595 available; but this can be changed to more easily debug problems
1596 occurring only in synchronous mode.
1598 set mi-async (on|off)
1600 Control whether MI asynchronous mode is preferred. This supersedes
1601 "set target-async" of previous GDB versions.
1603 * "set target-async" is deprecated as a CLI option and is now an alias
1604 for "set mi-async" (only puts MI into async mode).
1606 * Background execution commands (e.g., "c&", "s&", etc.) are now
1607 possible ``out of the box'' if the target supports them. Previously
1608 the user would need to explicitly enable the possibility with the
1609 "set target-async on" command.
1611 * New features in the GDB remote stub, GDBserver
1613 ** New option --debug-format=option1[,option2,...] allows one to add
1614 additional text to each output. At present only timestamps
1615 are supported: --debug-format=timestamps.
1616 Timestamps can also be turned on with the
1617 "monitor set debug-format timestamps" command from GDB.
1619 * The 'record instruction-history' command now starts counting instructions
1620 at one. This also affects the instruction ranges reported by the
1621 'record function-call-history' command when given the /i modifier.
1623 * The command 'record function-call-history' supports a new modifier '/c' to
1624 indent the function names based on their call stack depth.
1625 The fields for the '/i' and '/l' modifier have been reordered.
1626 The source line range is now prefixed with 'at'.
1627 The instruction range is now prefixed with 'inst'.
1628 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1629 "record instruction-history" and "list" commands.
1631 * The ranges given as arguments to the 'record function-call-history' and
1632 'record instruction-history' commands are now inclusive.
1634 * The btrace record target now supports the 'record goto' command.
1635 For locations inside the execution trace, the back trace is computed
1636 based on the information stored in the execution trace.
1638 * The btrace record target supports limited reverse execution and replay.
1639 The target does not record data and therefore does not allow reading
1640 memory or registers.
1642 * The "catch syscall" command now works on s390*-linux* targets.
1644 * The "compare-sections" command is no longer specific to target
1645 remote. It now works with all targets.
1647 * All native targets are now consistently called "native".
1648 Consequently, the "target child", "target GNU", "target djgpp",
1649 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1650 commands have been replaced with "target native". The QNX/NTO port
1651 leaves the "procfs" target in place and adds a "native" target for
1652 consistency with other ports. The impact on users should be minimal
1653 as these commands previously either throwed an error, or were
1654 no-ops. The target's name is visible in the output of the following
1655 commands: "help target", "info target", "info files", "maint print
1658 * The "target native" command now connects to the native target. This
1659 can be used to launch native programs even when "set
1660 auto-connect-native-target" is set to off.
1662 * GDB now supports access to Intel MPX registers on GNU/Linux.
1664 * Support for Intel AVX-512 registers on GNU/Linux.
1665 Support displaying and modifying Intel AVX-512 registers
1666 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1668 * New remote packets
1670 qXfer:btrace:read's annex
1671 The qXfer:btrace:read packet supports a new annex 'delta' to read
1672 branch trace incrementally.
1676 ** Valid Python operations on gdb.Value objects representing
1677 structs/classes invoke the corresponding overloaded operators if
1679 ** New `Xmethods' feature in the Python API. Xmethods are
1680 additional methods or replacements for existing methods of a C++
1681 class. This feature is useful for those cases where a method
1682 defined in C++ source code could be inlined or optimized out by
1683 the compiler, making it unavailable to GDB.
1686 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1688 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1689 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1690 its alias "share", instead.
1692 * The commands "set remotebaud" and "show remotebaud" are no longer
1693 supported. Use "set serial baud" and "show serial baud" (respectively)
1698 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1699 target-async". The latter is left as a deprecated alias of the
1700 former for backward compatibility. If the target supports it,
1701 CLI background execution commands are now always possible by
1702 default, independently of whether the frontend stated a
1703 preference for asynchronous execution with "-gdb-set mi-async".
1704 Previously "-gdb-set target-async off" affected both MI execution
1705 commands and CLI execution commands.
1707 *** Changes in GDB 7.7
1709 * Improved support for process record-replay and reverse debugging on
1710 arm*-linux* targets. Support for thumb32 and syscall instruction
1711 recording has been added.
1713 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1715 * GDB now supports Fission DWP file format version 2.
1716 http://gcc.gnu.org/wiki/DebugFission
1718 * New convenience function "$_isvoid", to check whether an expression
1719 is void. A void expression is an expression where the type of the
1720 result is "void". For example, some convenience variables may be
1721 "void" when evaluated (e.g., "$_exitcode" before the execution of
1722 the program being debugged; or an undefined convenience variable).
1723 Another example, when calling a function whose return type is
1726 * The "maintenance print objfiles" command now takes an optional regexp.
1728 * The "catch syscall" command now works on arm*-linux* targets.
1730 * GDB now consistently shows "<not saved>" when printing values of
1731 registers the debug info indicates have not been saved in the frame
1732 and there's nowhere to retrieve them from
1733 (callee-saved/call-clobbered registers):
1738 (gdb) info registers rax
1741 Before, the former would print "<optimized out>", and the latter
1742 "*value not available*".
1744 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1749 ** Frame filters and frame decorators have been added.
1750 ** Temporary breakpoints are now supported.
1751 ** Line tables representation has been added.
1752 ** New attribute 'parent_type' for gdb.Field objects.
1753 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1754 ** New attribute 'name' for gdb.Type objects.
1758 Nios II ELF nios2*-*-elf
1759 Nios II GNU/Linux nios2*-*-linux
1760 Texas Instruments MSP430 msp430*-*-elf
1762 * Removed native configurations
1764 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1765 been removed. ELF variants of these configurations are kept supported.
1767 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1768 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1769 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1770 i[34567]86-*-openbsd3.[0-3]
1771 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1772 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1773 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1777 Like "catch throw", but catches a re-thrown exception.
1778 maint check-psymtabs
1779 Renamed from old "maint check-symtabs".
1781 Perform consistency checks on symtabs.
1782 maint expand-symtabs
1783 Expand symtabs matching an optional regexp.
1786 Display the details of GDB configure-time options.
1788 maint set|show per-command
1789 maint set|show per-command space
1790 maint set|show per-command time
1791 maint set|show per-command symtab
1792 Enable display of per-command gdb resource usage.
1794 remove-symbol-file FILENAME
1795 remove-symbol-file -a ADDRESS
1796 Remove a symbol file added via add-symbol-file. The file to remove
1797 can be identified by its filename or by an address that lies within
1798 the boundaries of this symbol file in memory.
1801 info exceptions REGEXP
1802 Display the list of Ada exceptions defined in the program being
1803 debugged. If provided, only the exceptions whose names match REGEXP
1808 set debug symfile off|on
1810 Control display of debugging info regarding reading symbol files and
1811 symbol tables within those files
1813 set print raw frame-arguments
1814 show print raw frame-arguments
1815 Set/show whether to print frame arguments in raw mode,
1816 disregarding any defined pretty-printers.
1818 set remote trace-status-packet
1819 show remote trace-status-packet
1820 Set/show the use of remote protocol qTStatus packet.
1824 Control display of debugging messages related to Nios II targets.
1828 Control whether target-assisted range stepping is enabled.
1830 set startup-with-shell
1831 show startup-with-shell
1832 Specifies whether Unix child processes are started via a shell or
1837 Use the target memory cache for accesses to the code segment. This
1838 improves performance of remote debugging (particularly disassembly).
1840 * You can now use a literal value 'unlimited' for options that
1841 interpret 0 or -1 as meaning "unlimited". E.g., "set
1842 trace-buffer-size unlimited" is now an alias for "set
1843 trace-buffer-size -1" and "set height unlimited" is now an alias for
1846 * The "set debug symtab-create" debugging option of GDB has been changed to
1847 accept a verbosity level. 0 means "off", 1 provides basic debugging
1848 output, and values of 2 or greater provides more verbose output.
1850 * New command-line options
1852 Display the details of GDB configure-time options.
1854 * The command 'tsave' can now support new option '-ctf' to save trace
1855 buffer in Common Trace Format.
1857 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1860 * GDB now implements the the C++ 'typeid' operator.
1862 * The new convenience variable $_exception holds the exception being
1863 thrown or caught at an exception-related catchpoint.
1865 * The exception-related catchpoints, like "catch throw", now accept a
1866 regular expression which can be used to filter exceptions by type.
1868 * The new convenience variable $_exitsignal is automatically set to
1869 the terminating signal number when the program being debugged dies
1870 due to an uncaught signal.
1874 ** All MI commands now accept an optional "--language" option.
1875 Support for this feature can be verified by using the "-list-features"
1876 command, which should contain "language-option".
1878 ** The new command -info-gdb-mi-command allows the user to determine
1879 whether a GDB/MI command is supported or not.
1881 ** The "^error" result record returned when trying to execute an undefined
1882 GDB/MI command now provides a variable named "code" whose content is the
1883 "undefined-command" error code. Support for this feature can be verified
1884 by using the "-list-features" command, which should contain
1885 "undefined-command-error-code".
1887 ** The -trace-save MI command can optionally save trace buffer in Common
1890 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1892 ** The command -data-list-register-values now accepts an optional
1893 "--skip-unavailable" option. When used, only the available registers
1896 ** The new command -trace-frame-collected dumps collected variables,
1897 computed expressions, tvars, memory and registers in a traceframe.
1899 ** The commands -stack-list-locals, -stack-list-arguments and
1900 -stack-list-variables now accept an option "--skip-unavailable".
1901 When used, only the available locals or arguments are displayed.
1903 ** The -exec-run command now accepts an optional "--start" option.
1904 When used, the command follows the same semantics as the "start"
1905 command, stopping the program's execution at the start of its
1906 main subprogram. Support for this feature can be verified using
1907 the "-list-features" command, which should contain
1908 "exec-run-start-option".
1910 ** The new commands -catch-assert and -catch-exceptions insert
1911 catchpoints stopping the program when Ada exceptions are raised.
1913 ** The new command -info-ada-exceptions provides the equivalent of
1914 the new "info exceptions" command.
1916 * New system-wide configuration scripts
1917 A GDB installation now provides scripts suitable for use as system-wide
1918 configuration scripts for the following systems:
1922 * GDB now supports target-assigned range stepping with remote targets.
1923 This improves the performance of stepping source lines by reducing
1924 the number of control packets from/to GDB. See "New remote packets"
1927 * GDB now understands the element 'tvar' in the XML traceframe info.
1928 It has the id of the collected trace state variables.
1930 * On S/390 targets that provide the transactional-execution feature,
1931 the program interruption transaction diagnostic block (TDB) is now
1932 represented as a number of additional "registers" in GDB.
1934 * New remote packets
1938 The vCont packet supports a new 'r' action, that tells the remote
1939 stub to step through an address range itself, without GDB
1940 involvemement at each single-step.
1942 qXfer:libraries-svr4:read's annex
1943 The previously unused annex of the qXfer:libraries-svr4:read packet
1944 is now used to support passing an argument list. The remote stub
1945 reports support for this argument list to GDB's qSupported query.
1946 The defined arguments are "start" and "prev", used to reduce work
1947 necessary for library list updating, resulting in significant
1950 * New features in the GDB remote stub, GDBserver
1952 ** GDBserver now supports target-assisted range stepping. Currently
1953 enabled on x86/x86_64 GNU/Linux targets.
1955 ** GDBserver now adds element 'tvar' in the XML in the reply to
1956 'qXfer:traceframe-info:read'. It has the id of the collected
1957 trace state variables.
1959 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1962 * New 'z' formatter for printing and examining memory, this displays the
1963 value as hexadecimal zero padded on the left to the size of the type.
1965 * GDB can now use Windows x64 unwinding data.
1967 * The "set remotebaud" command has been replaced by "set serial baud".
1968 Similarly, "show remotebaud" has been replaced by "show serial baud".
1969 The "set remotebaud" and "show remotebaud" commands are still available
1970 to provide backward compatibility with older versions of GDB.
1972 *** Changes in GDB 7.6
1974 * Target record has been renamed to record-full.
1975 Record/replay is now enabled with the "record full" command.
1976 This also affects settings that are associated with full record/replay
1977 that have been moved from "set/show record" to "set/show record full":
1979 set|show record full insn-number-max
1980 set|show record full stop-at-limit
1981 set|show record full memory-query
1983 * A new record target "record-btrace" has been added. The new target
1984 uses hardware support to record the control-flow of a process. It
1985 does not support replaying the execution, but it implements the
1986 below new commands for investigating the recorded execution log.
1987 This new recording method can be enabled using:
1991 The "record-btrace" target is only available on Intel Atom processors
1992 and requires a Linux kernel 2.6.32 or later.
1994 * Two new commands have been added for record/replay to give information
1995 about the recorded execution without having to replay the execution.
1996 The commands are only supported by "record btrace".
1998 record instruction-history prints the execution history at
1999 instruction granularity
2001 record function-call-history prints the execution history at
2002 function granularity
2004 * New native configurations
2006 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2007 FreeBSD/powerpc powerpc*-*-freebsd
2008 x86_64/Cygwin x86_64-*-cygwin*
2009 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2013 ARM AArch64 aarch64*-*-elf
2014 ARM AArch64 GNU/Linux aarch64*-*-linux
2015 Lynx 178 PowerPC powerpc-*-lynx*178
2016 x86_64/Cygwin x86_64-*-cygwin*
2017 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2019 * If the configured location of system.gdbinit file (as given by the
2020 --with-system-gdbinit option at configure time) is in the
2021 data-directory (as specified by --with-gdb-datadir at configure
2022 time) or in one of its subdirectories, then GDB will look for the
2023 system-wide init file in the directory specified by the
2024 --data-directory command-line option.
2026 * New command line options:
2028 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2029 other initialization files, unlike -nx which disables all of them.
2031 * Removed command line options
2033 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2036 * The 'ptype' and 'whatis' commands now accept an argument to control
2039 * 'info proc' now works on some core files.
2043 ** Vectors can be created with gdb.Type.vector.
2045 ** Python's atexit.register now works in GDB.
2047 ** Types can be pretty-printed via a Python API.
2049 ** Python 3 is now supported (in addition to Python 2.4 or later)
2051 ** New class gdb.Architecture exposes GDB's internal representation
2052 of architecture in the Python API.
2054 ** New method Frame.architecture returns the gdb.Architecture object
2055 corresponding to the frame's architecture.
2057 * New Python-based convenience functions:
2059 ** $_memeq(buf1, buf2, length)
2060 ** $_streq(str1, str2)
2062 ** $_regex(str, regex)
2064 * The 'cd' command now defaults to using '~' (the home directory) if not
2067 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2068 default for GCC since November 2000.
2070 * The command 'forward-search' can now be abbreviated as 'fo'.
2072 * The command 'info tracepoints' can now display 'installed on target'
2073 or 'not installed on target' for each non-pending location of tracepoint.
2075 * New configure options
2077 --enable-libmcheck/--disable-libmcheck
2078 By default, development versions are built with -lmcheck on hosts
2079 that support it, in order to help track memory corruption issues.
2080 Release versions, on the other hand, are built without -lmcheck
2081 by default. The --enable-libmcheck/--disable-libmcheck configure
2082 options allow the user to override that default.
2083 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2084 This configure option allows the user to build GDB with
2085 libbabeltrace using which GDB can read Common Trace Format data.
2087 * New commands (for set/show, see "New options" below)
2090 Catch signals. This is similar to "handle", but allows commands and
2091 conditions to be attached.
2094 List the BFDs known to GDB.
2096 python-interactive [command]
2098 Start a Python interactive prompt, or evaluate the optional command
2099 and print the result of expressions.
2102 "py" is a new alias for "python".
2104 enable type-printer [name]...
2105 disable type-printer [name]...
2106 Enable or disable type printers.
2110 ** For the Renesas Super-H architecture, the "regs" command has been removed
2111 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2116 set print type methods (on|off)
2117 show print type methods
2118 Control whether method declarations are displayed by "ptype".
2119 The default is to show them.
2121 set print type typedefs (on|off)
2122 show print type typedefs
2123 Control whether typedef definitions are displayed by "ptype".
2124 The default is to show them.
2126 set filename-display basename|relative|absolute
2127 show filename-display
2128 Control the way in which filenames is displayed.
2129 The default is "relative", which preserves previous behavior.
2131 set trace-buffer-size
2132 show trace-buffer-size
2133 Request target to change the size of trace buffer.
2135 set remote trace-buffer-size-packet auto|on|off
2136 show remote trace-buffer-size-packet
2137 Control the use of the remote protocol `QTBuffer:size' packet.
2141 Control display of debugging messages related to ARM AArch64.
2144 set debug coff-pe-read
2145 show debug coff-pe-read
2146 Control display of debugging messages related to reading of COFF/PE
2151 Control display of debugging messages related to Mach-O symbols
2154 set debug notification
2155 show debug notification
2156 Control display of debugging info for async remote notification.
2160 ** Command parameter changes are now notified using new async record
2161 "=cmd-param-changed".
2162 ** Trace frame changes caused by command "tfind" are now notified using
2163 new async record "=traceframe-changed".
2164 ** The creation, deletion and modification of trace state variables
2165 are now notified using new async records "=tsv-created",
2166 "=tsv-deleted" and "=tsv-modified".
2167 ** The start and stop of process record are now notified using new
2168 async record "=record-started" and "=record-stopped".
2169 ** Memory changes are now notified using new async record
2171 ** The data-disassemble command response will include a "fullname" field
2172 containing the absolute file name when source has been requested.
2173 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2174 command, to allow pattern filling of memory areas.
2175 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2176 library load/unload events.
2177 ** The response to breakpoint commands and breakpoint async records
2178 includes an "installed" field containing a boolean state about each
2179 non-pending tracepoint location is whether installed on target or not.
2180 ** Output of the "-trace-status" command includes a "trace-file" field
2181 containing the name of the trace file being examined. This field is
2182 optional, and only present when examining a trace file.
2183 ** The "fullname" field is now always present along with the "file" field,
2184 even if the file cannot be found by GDB.
2186 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2187 You must have the LZMA library available when configuring GDB for this
2188 feature to be enabled. For more information, see:
2189 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2191 * New remote packets
2194 Set the size of trace buffer. The remote stub reports support for this
2195 packet to gdb's qSupported query.
2198 Enable Branch Trace Store (BTS)-based branch tracing for the current
2199 thread. The remote stub reports support for this packet to gdb's
2203 Disable branch tracing for the current thread. The remote stub reports
2204 support for this packet to gdb's qSupported query.
2207 Read the traced branches for the current thread. The remote stub
2208 reports support for this packet to gdb's qSupported query.
2210 *** Changes in GDB 7.5
2212 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2213 for more x32 ABI info.
2215 * GDB now supports access to MIPS DSP registers on Linux targets.
2217 * GDB now supports debugging microMIPS binaries.
2219 * The "info os" command on GNU/Linux can now display information on
2220 several new classes of objects managed by the operating system:
2221 "info os procgroups" lists process groups
2222 "info os files" lists file descriptors
2223 "info os sockets" lists internet-domain sockets
2224 "info os shm" lists shared-memory regions
2225 "info os semaphores" lists semaphores
2226 "info os msg" lists message queues
2227 "info os modules" lists loaded kernel modules
2229 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2230 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2231 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2232 options and inspect the probe arguments using the new $_probe_arg family
2233 of convenience variables. You can obtain more information about SystemTap
2234 in <http://sourceware.org/systemtap/>.
2236 * GDB now supports reversible debugging on ARM, it allows you to
2237 debug basic ARM and THUMB instructions, and provides
2238 record/replay support.
2240 * The option "symbol-reloading" has been deleted as it is no longer used.
2244 ** GDB commands implemented in Python can now be put in command class
2247 ** The "maint set python print-stack on|off" is now deleted.
2249 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2250 apply "flag enum"-style pretty-printing to any enum.
2252 ** gdb.lookup_symbol can now work when there is no current frame.
2254 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2255 the source at which the symbol was defined.
2257 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2258 method 'value'. The former indicates whether the symbol needs a
2259 frame in order to compute its value, and the latter computes the
2262 ** A new method 'referenced_value' on gdb.Value objects which can
2263 dereference pointer as well as C++ reference values.
2265 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2266 which return the global and static blocks (as gdb.Block objects),
2267 of the underlying symbol table, respectively.
2269 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2270 object associated with a PC value.
2272 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2273 of the address range occupied by code for the current source line.
2275 * Go language support.
2276 GDB now supports debugging programs written in the Go programming
2279 * GDBserver now supports stdio connections.
2280 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2282 * The binary "gdbtui" can no longer be built or installed.
2283 Use "gdb -tui" instead.
2285 * GDB will now print "flag" enums specially. A flag enum is one where
2286 all the enumerator values have no bits in common when pairwise
2287 "and"ed. When printing a value whose type is a flag enum, GDB will
2288 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2289 (gdb) print (enum E) 3
2292 * The filename part of a linespec will now match trailing components
2293 of a source file name. For example, "break gcc/expr.c:1000" will
2294 now set a breakpoint in build/gcc/expr.c, but not
2295 build/libcpp/expr.c.
2297 * The "info proc" and "generate-core-file" commands will now also
2298 work on remote targets connected to GDBserver on Linux.
2300 * The command "info catch" has been removed. It has been disabled
2301 since December 2007.
2303 * The "catch exception" and "catch assert" commands now accept
2304 a condition at the end of the command, much like the "break"
2305 command does. For instance:
2307 (gdb) catch exception Constraint_Error if Barrier = True
2309 Previously, it was possible to add a condition to such catchpoints,
2310 but it had to be done as a second step, after the catchpoint had been
2311 created, using the "condition" command.
2313 * The "info static-tracepoint-marker" command will now also work on
2314 native Linux targets with in-process agent.
2316 * GDB can now set breakpoints on inlined functions.
2318 * The .gdb_index section has been updated to include symbols for
2319 inlined functions. GDB will ignore older .gdb_index sections by
2320 default, which could cause symbol files to be loaded more slowly
2321 until their .gdb_index sections can be recreated. The new command
2322 "set use-deprecated-index-sections on" will cause GDB to use any older
2323 .gdb_index sections it finds. This will restore performance, but the
2324 ability to set breakpoints on inlined functions will be lost in symbol
2325 files with older .gdb_index sections.
2327 The .gdb_index section has also been updated to record more information
2328 about each symbol. This speeds up the "info variables", "info functions"
2329 and "info types" commands when used with programs having the .gdb_index
2330 section, as well as speeding up debugging with shared libraries using
2331 the .gdb_index section.
2333 * Ada support for GDB/MI Variable Objects has been added.
2335 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2340 ** New command -info-os is the MI equivalent of "info os".
2342 ** Output logs ("set logging" and related) now include MI output.
2346 ** "set use-deprecated-index-sections on|off"
2347 "show use-deprecated-index-sections on|off"
2348 Controls the use of deprecated .gdb_index sections.
2350 ** "catch load" and "catch unload" can be used to stop when a shared
2351 library is loaded or unloaded, respectively.
2353 ** "enable count" can be used to auto-disable a breakpoint after
2356 ** "info vtbl" can be used to show the virtual method tables for
2357 C++ and Java objects.
2359 ** "explore" and its sub commands "explore value" and "explore type"
2360 can be used to recursively explore values and types of
2361 expressions. These commands are available only if GDB is
2362 configured with '--with-python'.
2364 ** "info auto-load" shows status of all kinds of auto-loaded files,
2365 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2366 sequences of commands files, "info auto-load python-scripts"
2367 shows status of auto-loading Python script files,
2368 "info auto-load local-gdbinit" shows status of loading init file
2369 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2370 status of inferior specific thread debugging shared library loading.
2372 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2373 and "show auto-load-scripts" commands have been deprecated, use their
2374 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2375 and "show auto-load python-scripts" counterparts instead.
2377 ** "dprintf location,format,args..." creates a dynamic printf, which
2378 is basically a breakpoint that does a printf and immediately
2379 resumes your program's execution, so it is like a printf that you
2380 can insert dynamically at runtime instead of at compiletime.
2382 ** "set print symbol"
2384 Controls whether GDB attempts to display the symbol, if any,
2385 corresponding to addresses it prints. This defaults to "on", but
2386 you can set it to "off" to restore GDB's previous behavior.
2388 * Deprecated commands
2390 ** For the Renesas Super-H architecture, the "regs" command has been
2391 deprecated, and "info all-registers" should be used instead.
2395 Renesas RL78 rl78-*-elf
2396 HP OpenVMS ia64 ia64-hp-openvms*
2398 * GDBserver supports evaluation of breakpoint conditions. When
2399 support is advertised by GDBserver, GDB may be told to send the
2400 breakpoint conditions in bytecode form to GDBserver. GDBserver
2401 will only report the breakpoint trigger to GDB when its condition
2406 set mips compression
2407 show mips compression
2408 Select the compressed ISA encoding used in functions that have no symbol
2409 information available. The encoding can be set to either of:
2412 and is updated automatically from ELF file flags if available.
2414 set breakpoint condition-evaluation
2415 show breakpoint condition-evaluation
2416 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2417 GDBserver ("target"). Default option "auto" chooses the most efficient
2419 This option can improve debugger efficiency depending on the speed of the
2423 Disable auto-loading globally.
2426 Show auto-loading setting of all kinds of auto-loaded files.
2428 set auto-load gdb-scripts on|off
2429 show auto-load gdb-scripts
2430 Control auto-loading of GDB canned sequences of commands files.
2432 set auto-load python-scripts on|off
2433 show auto-load python-scripts
2434 Control auto-loading of Python script files.
2436 set auto-load local-gdbinit on|off
2437 show auto-load local-gdbinit
2438 Control loading of init file (.gdbinit) from current directory.
2440 set auto-load libthread-db on|off
2441 show auto-load libthread-db
2442 Control auto-loading of inferior specific thread debugging shared library.
2444 set auto-load scripts-directory <dir1>[:<dir2>...]
2445 show auto-load scripts-directory
2446 Set a list of directories from which to load auto-loaded scripts.
2447 Automatically loaded Python scripts and GDB scripts are located in one
2448 of the directories listed by this option.
2449 The delimiter (':' above) may differ according to the host platform.
2451 set auto-load safe-path <dir1>[:<dir2>...]
2452 show auto-load safe-path
2453 Set a list of directories from which it is safe to auto-load files.
2454 The delimiter (':' above) may differ according to the host platform.
2456 set debug auto-load on|off
2457 show debug auto-load
2458 Control display of debugging info for auto-loading the files above.
2460 set dprintf-style gdb|call|agent
2462 Control the way in which a dynamic printf is performed; "gdb"
2463 requests a GDB printf command, while "call" causes dprintf to call a
2464 function in the inferior. "agent" requests that the target agent
2465 (such as GDBserver) do the printing.
2467 set dprintf-function <expr>
2468 show dprintf-function
2469 set dprintf-channel <expr>
2470 show dprintf-channel
2471 Set the function and optional first argument to the call when using
2472 the "call" style of dynamic printf.
2474 set disconnected-dprintf on|off
2475 show disconnected-dprintf
2476 Control whether agent-style dynamic printfs continue to be in effect
2477 after GDB disconnects.
2479 * New configure options
2481 --with-auto-load-dir
2482 Configure default value for the 'set auto-load scripts-directory'
2483 setting above. It defaults to '$debugdir:$datadir/auto-load',
2484 $debugdir representing global debugging info directories (available
2485 via 'show debug-file-directory') and $datadir representing GDB's data
2486 directory (available via 'show data-directory').
2488 --with-auto-load-safe-path
2489 Configure default value for the 'set auto-load safe-path' setting
2490 above. It defaults to the --with-auto-load-dir setting.
2492 --without-auto-load-safe-path
2493 Set 'set auto-load safe-path' to '/', effectively disabling this
2496 * New remote packets
2498 z0/z1 conditional breakpoints extension
2500 The z0/z1 breakpoint insertion packets have been extended to carry
2501 a list of conditional expressions over to the remote stub depending on the
2502 condition evaluation mode. The use of this extension can be controlled
2503 via the "set remote conditional-breakpoints-packet" command.
2507 Specify the signals which the remote stub may pass to the debugged
2508 program without GDB involvement.
2510 * New command line options
2512 --init-command=FILE, -ix Like --command, -x but execute it
2513 before loading inferior.
2514 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2515 execute it before loading inferior.
2517 *** Changes in GDB 7.4
2519 * GDB now handles ambiguous linespecs more consistently; the existing
2520 FILE:LINE support has been expanded to other types of linespecs. A
2521 breakpoint will now be set on all matching locations in all
2522 inferiors, and locations will be added or removed according to
2525 * GDB now allows you to skip uninteresting functions and files when
2526 stepping with the "skip function" and "skip file" commands.
2528 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2529 and "show remote hardware-watchpoint-length-limit". These allows to
2530 set or show the maximum length limit (in bytes) of a remote
2531 target hardware watchpoint.
2533 This allows e.g. to use "unlimited" hardware watchpoints with the
2534 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2535 watchpoints are slower than real hardware watchpoints but are
2536 significantly faster than gdb software watchpoints.
2540 ** The register_pretty_printer function in module gdb.printing now takes
2541 an optional `replace' argument. If True, the new printer replaces any
2544 ** The "maint set python print-stack on|off" command has been
2545 deprecated and will be deleted in GDB 7.5.
2546 A new command: "set python print-stack none|full|message" has
2547 replaced it. Additionally, the default for "print-stack" is
2548 now "message", which just prints the error message without
2551 ** A prompt substitution hook (prompt_hook) is now available to the
2554 ** A new Python module, gdb.prompt has been added to the GDB Python
2555 modules library. This module provides functionality for
2556 escape sequences in prompts (used by set/show
2557 extended-prompt). These escape sequences are replaced by their
2558 corresponding value.
2560 ** Python commands and convenience-functions located in
2561 'data-directory'/python/gdb/command and
2562 'data-directory'/python/gdb/function are now automatically loaded
2565 ** Blocks now provide four new attributes. global_block and
2566 static_block will return the global and static blocks
2567 respectively. is_static and is_global are boolean attributes
2568 that indicate if the block is one of those two types.
2570 ** Symbols now provide the "type" attribute, the type of the symbol.
2572 ** The "gdb.breakpoint" function has been deprecated in favor of
2575 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2576 of a function. This class is based on the "finish" command
2577 available in the CLI.
2579 ** Type objects for struct and union types now allow access to
2580 the fields using standard Python dictionary (mapping) methods.
2581 For example, "some_type['myfield']" now works, as does
2582 "some_type.items()".
2584 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2587 ** A new function, "deep_items" has been added to the gdb.types
2588 module in the GDB Python modules library. This function returns
2589 an iterator over the fields of a struct or union type. Unlike
2590 the standard Python "iteritems" method, it will recursively traverse
2591 any anonymous fields.
2595 ** "*stopped" events can report several new "reason"s, such as
2598 ** Breakpoint changes are now notified using new async records, like
2599 "=breakpoint-modified".
2601 ** New command -ada-task-info.
2603 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2604 $sdir specifies the default system locations of shared libraries.
2605 $pdir specifies the directory where the libpthread used by the application
2608 GDB no longer looks in $sdir and $pdir after it has searched the directories
2609 mentioned in libthread-db-search-path. If you want to search those
2610 directories, they must be specified in libthread-db-search-path.
2611 The default value of libthread-db-search-path on GNU/Linux and Solaris
2612 systems is now "$sdir:$pdir".
2614 $pdir is not supported by gdbserver, it is currently ignored.
2615 $sdir is supported by gdbserver.
2617 * New configure option --with-iconv-bin.
2618 When using the internationalization support like the one in the GNU C
2619 library, GDB will invoke the "iconv" program to get a list of supported
2620 character sets. If this program lives in a non-standard location, one can
2621 use this option to specify where to find it.
2623 * When natively debugging programs on PowerPC BookE processors running
2624 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2625 watchpoints, which specify a mask in addition to an address to watch.
2626 The mask specifies that some bits of an address (the bits which are
2627 reset in the mask) should be ignored when matching the address accessed
2628 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2629 section in the user manual for more details.
2631 * The new option --once causes GDBserver to stop listening for connections once
2632 the first connection is made. The listening port used by GDBserver will
2633 become available after that.
2635 * New commands "info macros" and "alias" have been added.
2637 * New function parameters suffix @entry specifies value of function parameter
2638 at the time the function got called. Entry values are available only since
2644 "!" is now an alias of the "shell" command.
2645 Note that no space is needed between "!" and SHELL COMMAND.
2649 watch EXPRESSION mask MASK_VALUE
2650 The watch command now supports the mask argument which allows creation
2651 of masked watchpoints, if the current architecture supports this feature.
2653 info auto-load-scripts [REGEXP]
2654 This command was formerly named "maintenance print section-scripts".
2655 It is now generally useful and is no longer a maintenance-only command.
2657 info macro [-all] [--] MACRO
2658 The info macro command has new options `-all' and `--'. The first for
2659 printing all definitions of a macro. The second for explicitly specifying
2660 the end of arguments and the beginning of the macro name in case the macro
2661 name starts with a hyphen.
2663 collect[/s] EXPRESSIONS
2664 The tracepoint collect command now takes an optional modifier "/s"
2665 that directs it to dereference pointer-to-character types and
2666 collect the bytes of memory up to a zero byte. The behavior is
2667 similar to what you see when you use the regular print command on a
2668 string. An optional integer following the "/s" sets a bound on the
2669 number of bytes that will be collected.
2672 The trace start command now interprets any supplied arguments as a
2673 note to be recorded with the trace run, with an effect similar to
2674 setting the variable trace-notes.
2677 The trace stop command now interprets any arguments as a note to be
2678 mentioned along with the tstatus report that the trace was stopped
2679 with a command. The effect is similar to setting the variable
2682 * Tracepoints can now be enabled and disabled at any time after a trace
2683 experiment has been started using the standard "enable" and "disable"
2684 commands. It is now possible to start a trace experiment with no enabled
2685 tracepoints; GDB will display a warning, but will allow the experiment to
2686 begin, assuming that tracepoints will be enabled as needed while the trace
2689 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2690 locations with 4-byte instructions, when they were previously
2691 limited to locations with instructions of 5 bytes or longer.
2695 set debug dwarf2-read
2696 show debug dwarf2-read
2697 Turns on or off display of debugging messages related to reading
2698 DWARF debug info. The default is off.
2700 set debug symtab-create
2701 show debug symtab-create
2702 Turns on or off display of debugging messages related to symbol table
2703 creation. The default is off.
2706 show extended-prompt
2707 Set the GDB prompt, and allow escape sequences to be inserted to
2708 display miscellaneous information (see 'help set extended-prompt'
2709 for the list of sequences). This prompt (and any information
2710 accessed through the escape sequences) is updated every time the
2711 prompt is displayed.
2713 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2714 show print entry-values
2715 Set printing of frame argument values at function entry. In some cases
2716 GDB can determine the value of function argument which was passed by the
2717 function caller, even if the value was modified inside the called function.
2719 set debug entry-values
2720 show debug entry-values
2721 Control display of debugging info for determining frame argument values at
2722 function entry and virtual tail call frames.
2724 set basenames-may-differ
2725 show basenames-may-differ
2726 Set whether a source file may have multiple base names.
2727 (A "base name" is the name of a file with the directory part removed.
2728 Example: The base name of "/home/user/hello.c" is "hello.c".)
2729 If set, GDB will canonicalize file names (e.g., expand symlinks)
2730 before comparing them. Canonicalization is an expensive operation,
2731 but it allows the same file be known by more than one base name.
2732 If not set (the default), all source files are assumed to have just
2733 one base name, and gdb will do file name comparisons more efficiently.
2739 Set a user name and notes for the current and any future trace runs.
2740 This is useful for long-running and/or disconnected traces, to
2741 inform others (or yourself) as to who is running the trace, supply
2742 contact information, or otherwise explain what is going on.
2744 set trace-stop-notes
2745 show trace-stop-notes
2746 Set a note attached to the trace run, that is displayed when the
2747 trace has been stopped by a tstop command. This is useful for
2748 instance as an explanation, if you are stopping a trace run that was
2749 started by someone else.
2751 * New remote packets
2755 Dynamically enable a tracepoint in a started trace experiment.
2759 Dynamically disable a tracepoint in a started trace experiment.
2763 Set the user and notes of the trace run.
2767 Query the current status of a tracepoint.
2771 Query the minimum length of instruction at which a fast tracepoint may
2774 * Dcache size (number of lines) and line-size are now runtime-configurable
2775 via "set dcache line" and "set dcache line-size" commands.
2779 Texas Instruments TMS320C6x tic6x-*-*
2783 Renesas RL78 rl78-*-elf
2785 *** Changes in GDB 7.3.1
2787 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2789 *** Changes in GDB 7.3
2791 * GDB has a new command: "thread find [REGEXP]".
2792 It finds the thread id whose name, target id, or thread extra info
2793 matches the given regular expression.
2795 * The "catch syscall" command now works on mips*-linux* targets.
2797 * The -data-disassemble MI command now supports modes 2 and 3 for
2798 dumping the instruction opcodes.
2800 * New command line options
2802 -data-directory DIR Specify DIR as the "data-directory".
2803 This is mostly for testing purposes.
2805 * The "maint set python auto-load on|off" command has been renamed to
2806 "set auto-load-scripts on|off".
2808 * GDB has a new command: "set directories".
2809 It is like the "dir" command except that it replaces the
2810 source path list instead of augmenting it.
2812 * GDB now understands thread names.
2814 On GNU/Linux, "info threads" will display the thread name as set by
2815 prctl or pthread_setname_np.
2817 There is also a new command, "thread name", which can be used to
2818 assign a name internally for GDB to display.
2821 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2822 has been integrated into GDB.
2826 ** The function gdb.Write now accepts an optional keyword 'stream'.
2827 This keyword, when provided, will direct the output to either
2828 stdout, stderr, or GDB's logging output.
2830 ** Parameters can now be be sub-classed in Python, and in particular
2831 you may implement the get_set_doc and get_show_doc functions.
2832 This improves how Parameter set/show documentation is processed
2833 and allows for more dynamic content.
2835 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2836 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2837 have an is_valid method.
2839 ** Breakpoints can now be sub-classed in Python, and in particular
2840 you may implement a 'stop' function that is executed each time
2841 the inferior reaches that breakpoint.
2843 ** New function gdb.lookup_global_symbol looks up a global symbol.
2845 ** GDB values in Python are now callable if the value represents a
2846 function. For example, if 'some_value' represents a function that
2847 takes two integer parameters and returns a value, you can call
2848 that function like so:
2850 result = some_value (10,20)
2852 ** Module gdb.types has been added.
2853 It contains a collection of utilities for working with gdb.Types objects:
2854 get_basic_type, has_field, make_enum_dict.
2856 ** Module gdb.printing has been added.
2857 It contains utilities for writing and registering pretty-printers.
2858 New classes: PrettyPrinter, SubPrettyPrinter,
2859 RegexpCollectionPrettyPrinter.
2860 New function: register_pretty_printer.
2862 ** New commands "info pretty-printers", "enable pretty-printer" and
2863 "disable pretty-printer" have been added.
2865 ** gdb.parameter("directories") is now available.
2867 ** New function gdb.newest_frame returns the newest frame in the
2870 ** The gdb.InferiorThread class has a new "name" attribute. This
2871 holds the thread's name.
2873 ** Python Support for Inferior events.
2874 Python scripts can add observers to be notified of events
2875 occurring in the process being debugged.
2876 The following events are currently supported:
2877 - gdb.events.cont Continue event.
2878 - gdb.events.exited Inferior exited event.
2879 - gdb.events.stop Signal received, and Breakpoint hit events.
2883 ** GDB now puts template parameters in scope when debugging in an
2884 instantiation. For example, if you have:
2886 template<int X> int func (void) { return X; }
2888 then if you step into func<5>, "print X" will show "5". This
2889 feature requires proper debuginfo support from the compiler; it
2890 was added to GCC 4.5.
2892 ** The motion commands "next", "finish", "until", and "advance" now
2893 work better when exceptions are thrown. In particular, GDB will
2894 no longer lose control of the inferior; instead, the GDB will
2895 stop the inferior at the point at which the exception is caught.
2896 This functionality requires a change in the exception handling
2897 code that was introduced in GCC 4.5.
2899 * GDB now follows GCC's rules on accessing volatile objects when
2900 reading or writing target state during expression evaluation.
2901 One notable difference to prior behavior is that "print x = 0"
2902 no longer generates a read of x; the value of the assignment is
2903 now always taken directly from the value being assigned.
2905 * GDB now has some support for using labels in the program's source in
2906 linespecs. For instance, you can use "advance label" to continue
2907 execution to a label.
2909 * GDB now has support for reading and writing a new .gdb_index
2910 section. This section holds a fast index of DWARF debugging
2911 information and can be used to greatly speed up GDB startup and
2912 operation. See the documentation for `save gdb-index' for details.
2914 * The "watch" command now accepts an optional "-location" argument.
2915 When used, this causes GDB to watch the memory referred to by the
2916 expression. Such a watchpoint is never deleted due to it going out
2919 * GDB now supports thread debugging of core dumps on GNU/Linux.
2921 GDB now activates thread debugging using the libthread_db library
2922 when debugging GNU/Linux core dumps, similarly to when debugging
2923 live processes. As a result, when debugging a core dump file, GDB
2924 is now able to display pthread_t ids of threads. For example, "info
2925 threads" shows the same output as when debugging the process when it
2926 was live. In earlier releases, you'd see something like this:
2929 * 1 LWP 6780 main () at main.c:10
2931 While now you see this:
2934 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2936 It is also now possible to inspect TLS variables when debugging core
2939 When debugging a core dump generated on a machine other than the one
2940 used to run GDB, you may need to point GDB at the correct
2941 libthread_db library with the "set libthread-db-search-path"
2942 command. See the user manual for more details on this command.
2944 * When natively debugging programs on PowerPC BookE processors running
2945 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2946 which stop execution of the inferior whenever it executes an instruction
2947 at any address within the specified range. See the "PowerPC Embedded"
2948 section in the user manual for more details.
2950 * New features in the GDB remote stub, GDBserver
2952 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2953 and i686 LynxOS (version 5.x).
2955 ** GDBserver is now supported on Blackfin Linux.
2957 * New native configurations
2959 ia64 HP-UX ia64-*-hpux*
2963 Analog Devices, Inc. Blackfin Processor bfin-*
2965 * Ada task switching is now supported on sparc-elf targets when
2966 debugging a program using the Ravenscar Profile. For more information,
2967 see the "Tasking Support when using the Ravenscar Profile" section
2968 in the GDB user manual.
2970 * Guile support was removed.
2972 * New features in the GNU simulator
2974 ** The --map-info flag lists all known core mappings.
2976 ** CFI flashes may be simulated via the "cfi" device.
2978 *** Changes in GDB 7.2
2980 * Shared library support for remote targets by default
2982 When GDB is configured for a generic, non-OS specific target, like
2983 for example, --target=arm-eabi or one of the many *-*-elf targets,
2984 GDB now queries remote stubs for loaded shared libraries using the
2985 `qXfer:libraries:read' packet. Previously, shared library support
2986 was always disabled for such configurations.
2990 ** Argument Dependent Lookup (ADL)
2992 In C++ ADL lookup directs function search to the namespaces of its
2993 arguments even if the namespace has not been imported.
3003 Here the compiler will search for `foo' in the namespace of 'b'
3004 and find A::foo. GDB now supports this. This construct is commonly
3005 used in the Standard Template Library for operators.
3007 ** Improved User Defined Operator Support
3009 In addition to member operators, GDB now supports lookup of operators
3010 defined in a namespace and imported with a `using' directive, operators
3011 defined in the global scope, operators imported implicitly from an
3012 anonymous namespace, and the ADL operators mentioned in the previous
3014 GDB now also supports proper overload resolution for all the previously
3015 mentioned flavors of operators.
3017 ** static const class members
3019 Printing of static const class members that are initialized in the
3020 class definition has been fixed.
3022 * Windows Thread Information Block access.
3024 On Windows targets, GDB now supports displaying the Windows Thread
3025 Information Block (TIB) structure. This structure is visible either
3026 by using the new command `info w32 thread-information-block' or, by
3027 dereferencing the new convenience variable named `$_tlb', a
3028 thread-specific pointer to the TIB. This feature is also supported
3029 when remote debugging using GDBserver.
3031 * Static tracepoints
3033 Static tracepoints are calls in the user program into a tracing
3034 library. One such library is a port of the LTTng kernel tracer to
3035 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3036 When debugging with GDBserver, GDB now supports combining the GDB
3037 tracepoint machinery with such libraries. For example: the user can
3038 use GDB to probe a static tracepoint marker (a call from the user
3039 program into the tracing library) with the new "strace" command (see
3040 "New commands" below). This creates a "static tracepoint" in the
3041 breakpoint list, that can be manipulated with the same feature set
3042 as fast and regular tracepoints. E.g., collect registers, local and
3043 global variables, collect trace state variables, and define
3044 tracepoint conditions. In addition, the user can collect extra
3045 static tracepoint marker specific data, by collecting the new
3046 $_sdata internal variable. When analyzing the trace buffer, you can
3047 inspect $_sdata like any other variable available to GDB. For more
3048 information, see the "Tracepoints" chapter in GDB user manual. New
3049 remote packets have been defined to support static tracepoints, see
3050 the "New remote packets" section below.
3052 * Better reconstruction of tracepoints after disconnected tracing
3054 GDB will attempt to download the original source form of tracepoint
3055 definitions when starting a trace run, and then will upload these
3056 upon reconnection to the target, resulting in a more accurate
3057 reconstruction of the tracepoints that are in use on the target.
3061 You can now exercise direct control over the ways that GDB can
3062 affect your program. For instance, you can disallow the setting of
3063 breakpoints, so that the program can run continuously (assuming
3064 non-stop mode). In addition, the "observer" variable is available
3065 to switch all of the different controls; in observer mode, GDB
3066 cannot affect the target's behavior at all, which is useful for
3067 tasks like diagnosing live systems in the field.
3069 * The new convenience variable $_thread holds the number of the
3072 * New remote packets
3076 Return the address of the Windows Thread Information Block of a given thread.
3080 In response to several of the tracepoint packets, the target may now
3081 also respond with a number of intermediate `qRelocInsn' request
3082 packets before the final result packet, to have GDB handle
3083 relocating an instruction to execute at a different address. This
3084 is particularly useful for stubs that support fast tracepoints. GDB
3085 reports support for this feature in the qSupported packet.
3089 List static tracepoint markers in the target program.
3093 List static tracepoint markers at a given address in the target
3096 qXfer:statictrace:read
3098 Read the static trace data collected (by a `collect $_sdata'
3099 tracepoint action). The remote stub reports support for this packet
3100 to gdb's qSupported query.
3104 Send the current settings of GDB's permission flags.
3108 Send part of the source (textual) form of a tracepoint definition,
3109 which includes location, conditional, and action list.
3111 * The source command now accepts a -s option to force searching for the
3112 script in the source search path even if the script name specifies
3115 * New features in the GDB remote stub, GDBserver
3117 - GDBserver now support tracepoints (including fast tracepoints, and
3118 static tracepoints). The feature is currently supported by the
3119 i386-linux and amd64-linux builds. See the "Tracepoints support
3120 in gdbserver" section in the manual for more information.
3122 GDBserver JIT compiles the tracepoint's conditional agent
3123 expression bytecode into native code whenever possible for low
3124 overhead dynamic tracepoints conditionals. For such tracepoints,
3125 an expression that examines program state is evaluated when the
3126 tracepoint is reached, in order to determine whether to capture
3127 trace data. If the condition is simple and false, processing the
3128 tracepoint finishes very quickly and no data is gathered.
3130 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3131 for static tracepoints support.
3133 - GDBserver now supports x86_64 Windows 64-bit debugging.
3135 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3136 it understands register description.
3138 * The --batch flag now disables pagination and queries.
3140 * X86 general purpose registers
3142 GDB now supports reading/writing byte, word and double-word x86
3143 general purpose registers directly. This means you can use, say,
3144 $ah or $ax to refer, respectively, to the byte register AH and
3145 16-bit word register AX that are actually portions of the 32-bit
3146 register EAX or 64-bit register RAX.
3148 * The `commands' command now accepts a range of breakpoints to modify.
3149 A plain `commands' following a command that creates multiple
3150 breakpoints affects all the breakpoints set by that command. This
3151 applies to breakpoints set by `rbreak', and also applies when a
3152 single `break' command creates multiple breakpoints (e.g.,
3153 breakpoints on overloaded c++ functions).
3155 * The `rbreak' command now accepts a filename specification as part of
3156 its argument, limiting the functions selected by the regex to those
3157 in the specified file.
3159 * Support for remote debugging Windows and SymbianOS shared libraries
3160 from Unix hosts has been improved. Non Windows GDB builds now can
3161 understand target reported file names that follow MS-DOS based file
3162 system semantics, such as file names that include drive letters and
3163 use the backslash character as directory separator. This makes it
3164 possible to transparently use the "set sysroot" and "set
3165 solib-search-path" on Unix hosts to point as host copies of the
3166 target's shared libraries. See the new command "set
3167 target-file-system-kind" described below, and the "Commands to
3168 specify files" section in the user manual for more information.
3172 eval template, expressions...
3173 Convert the values of one or more expressions under the control
3174 of the string template to a command line, and call it.
3176 set target-file-system-kind unix|dos-based|auto
3177 show target-file-system-kind
3178 Set or show the assumed file system kind for target reported file
3181 save breakpoints <filename>
3182 Save all current breakpoint definitions to a file suitable for use
3183 in a later debugging session. To read the saved breakpoint
3184 definitions, use the `source' command.
3186 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3189 info static-tracepoint-markers
3190 Display information about static tracepoint markers in the target.
3192 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3193 Define a static tracepoint by probing a marker at the given
3194 function, line, address, or marker ID.
3198 Enable and disable observer mode.
3200 set may-write-registers on|off
3201 set may-write-memory on|off
3202 set may-insert-breakpoints on|off
3203 set may-insert-tracepoints on|off
3204 set may-insert-fast-tracepoints on|off
3205 set may-interrupt on|off
3206 Set individual permissions for GDB effects on the target. Note that
3207 some of these settings can have undesirable or surprising
3208 consequences, particularly when changed in the middle of a session.
3209 For instance, disabling the writing of memory can prevent
3210 breakpoints from being inserted, cause single-stepping to fail, or
3211 even crash your program, if you disable after breakpoints have been
3212 inserted. However, GDB should not crash.
3214 set record memory-query on|off
3215 show record memory-query
3216 Control whether to stop the inferior if memory changes caused
3217 by an instruction cannot be recorded.
3222 The disassemble command now supports "start,+length" form of two arguments.
3226 ** GDB now provides a new directory location, called the python directory,
3227 where Python scripts written for GDB can be installed. The location
3228 of that directory is <data-directory>/python, where <data-directory>
3229 is the GDB data directory. For more details, see section `Scripting
3230 GDB using Python' in the manual.
3232 ** The GDB Python API now has access to breakpoints, symbols, symbol
3233 tables, program spaces, inferiors, threads and frame's code blocks.
3234 Additionally, GDB Parameters can now be created from the API, and
3235 manipulated via set/show in the CLI.
3237 ** New functions gdb.target_charset, gdb.target_wide_charset,
3238 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3240 ** New exception gdb.GdbError.
3242 ** Pretty-printers are now also looked up in the current program space.
3244 ** Pretty-printers can now be individually enabled and disabled.
3246 ** GDB now looks for names of Python scripts to auto-load in a
3247 special section named `.debug_gdb_scripts', in addition to looking
3248 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3250 * Tracepoint actions were unified with breakpoint commands. In particular,
3251 there are no longer differences in "info break" output for breakpoints and
3252 tracepoints and the "commands" command can be used for both tracepoints and
3253 regular breakpoints.
3257 ARM Symbian arm*-*-symbianelf*
3259 * D language support.
3260 GDB now supports debugging programs written in the D programming
3263 * GDB now supports the extended ptrace interface for PowerPC which is
3264 available since Linux kernel version 2.6.34. This automatically enables
3265 any hardware breakpoints and additional hardware watchpoints available in
3266 the processor. The old ptrace interface exposes just one hardware
3267 watchpoint and no hardware breakpoints.
3269 * GDB is now able to use the Data Value Compare (DVC) register available on
3270 embedded PowerPC processors to implement in hardware simple watchpoint
3271 conditions of the form:
3273 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3275 This works in native GDB running on Linux kernels with the extended ptrace
3276 interface mentioned above.
3278 *** Changes in GDB 7.1
3282 ** Namespace Support
3284 GDB now supports importing of namespaces in C++. This enables the
3285 user to inspect variables from imported namespaces. Support for
3286 namepace aliasing has also been added. So, if a namespace is
3287 aliased in the current scope (e.g. namepace C=A; ) the user can
3288 print variables using the alias (e.g. (gdb) print C::x).
3292 All known bugs relating to the printing of virtual base class were
3293 fixed. It is now possible to call overloaded static methods using a
3298 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3299 and reinterpret_cast<> are now handled by the C++ expression parser.
3303 Xilinx MicroBlaze microblaze-*-*
3308 Xilinx MicroBlaze microblaze
3311 * Multi-program debugging.
3313 GDB now has support for multi-program (a.k.a. multi-executable or
3314 multi-exec) debugging. This allows for debugging multiple inferiors
3315 simultaneously each running a different program under the same GDB
3316 session. See "Debugging Multiple Inferiors and Programs" in the
3317 manual for more information. This implied some user visible changes
3318 in the multi-inferior support. For example, "info inferiors" now
3319 lists inferiors that are not running yet or that have exited
3320 already. See also "New commands" and "New options" below.
3322 * New tracing features
3324 GDB's tracepoint facility now includes several new features:
3326 ** Trace state variables
3328 GDB tracepoints now include support for trace state variables, which
3329 are variables managed by the target agent during a tracing
3330 experiment. They are useful for tracepoints that trigger each
3331 other, so for instance one tracepoint can count hits in a variable,
3332 and then a second tracepoint has a condition that is true when the
3333 count reaches a particular value. Trace state variables share the
3334 $-syntax of GDB convenience variables, and can appear in both
3335 tracepoint actions and condition expressions. Use the "tvariable"
3336 command to create, and "info tvariables" to view; see "Trace State
3337 Variables" in the manual for more detail.
3341 GDB now includes an option for defining fast tracepoints, which
3342 targets may implement more efficiently, such as by installing a jump
3343 into the target agent rather than a trap instruction. The resulting
3344 speedup can be by two orders of magnitude or more, although the
3345 tradeoff is that some program locations on some target architectures
3346 might not allow fast tracepoint installation, for instance if the
3347 instruction to be replaced is shorter than the jump. To request a
3348 fast tracepoint, use the "ftrace" command, with syntax identical to
3349 the regular trace command.
3351 ** Disconnected tracing
3353 It is now possible to detach GDB from the target while it is running
3354 a trace experiment, then reconnect later to see how the experiment
3355 is going. In addition, a new variable disconnected-tracing lets you
3356 tell the target agent whether to continue running a trace if the
3357 connection is lost unexpectedly.
3361 GDB now has the ability to save the trace buffer into a file, and
3362 then use that file as a target, similarly to you can do with
3363 corefiles. You can select trace frames, print data that was
3364 collected in them, and use tstatus to display the state of the
3365 tracing run at the moment that it was saved. To create a trace
3366 file, use "tsave <filename>", and to use it, do "target tfile
3369 ** Circular trace buffer
3371 You can ask the target agent to handle the trace buffer as a
3372 circular buffer, discarding the oldest trace frames to make room for
3373 newer ones, by setting circular-trace-buffer to on. This feature may
3374 not be available for all target agents.
3379 The disassemble command, when invoked with two arguments, now requires
3380 the arguments to be comma-separated.
3383 The info variables command now displays variable definitions. Files
3384 which only declare a variable are not shown.
3387 The source command is now capable of sourcing Python scripts.
3388 This feature is dependent on the debugger being build with Python
3391 Related to this enhancement is also the introduction of a new command
3392 "set script-extension" (see below).
3394 * New commands (for set/show, see "New options" below)
3396 record save [<FILENAME>]
3397 Save a file (in core file format) containing the process record
3398 execution log for replay debugging at a later time.
3400 record restore <FILENAME>
3401 Restore the process record execution log that was saved at an
3402 earlier time, for replay debugging.
3404 add-inferior [-copies <N>] [-exec <FILENAME>]
3407 clone-inferior [-copies <N>] [ID]
3408 Make a new inferior ready to execute the same program another
3409 inferior has loaded.
3414 maint info program-spaces
3415 List the program spaces loaded into GDB.
3417 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3418 show remote interrupt-sequence
3419 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3420 as the sequence to the remote target in order to interrupt the execution.
3421 Ctrl-C is a default. Some system prefers BREAK which is high level of
3422 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3423 Magic SysRq g. It is BREAK signal and character 'g'.
3425 set remote interrupt-on-connect [on | off]
3426 show remote interrupt-on-connect
3427 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3428 remote target when gdb connects to it. This is needed when you debug
3431 set remotebreak [on | off]
3433 Deprecated. Use "set/show remote interrupt-sequence" instead.
3435 tvariable $NAME [ = EXP ]
3436 Create or modify a trace state variable.
3439 List trace state variables and their values.
3441 delete tvariable $NAME ...
3442 Delete one or more trace state variables.
3445 Evaluate the given expressions without collecting anything into the
3446 trace buffer. (Valid in tracepoint actions only.)
3448 ftrace FN / FILE:LINE / *ADDR
3449 Define a fast tracepoint at the given function, line, or address.
3451 * New expression syntax
3453 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3454 GDB now parses 0b101010 identically with 42.
3458 set follow-exec-mode new|same
3459 show follow-exec-mode
3460 Control whether GDB reuses the same inferior across an exec call or
3461 creates a new one. This is useful to be able to restart the old
3462 executable after the inferior having done an exec call.
3464 set default-collect EXPR, ...
3465 show default-collect
3466 Define a list of expressions to be collected at each tracepoint.
3467 This is a useful way to ensure essential items are not overlooked,
3468 such as registers or a critical global variable.
3470 set disconnected-tracing
3471 show disconnected-tracing
3472 If set to 1, the target is instructed to continue tracing if it
3473 loses its connection to GDB. If 0, the target is to stop tracing
3476 set circular-trace-buffer
3477 show circular-trace-buffer
3478 If set to on, the target is instructed to use a circular trace buffer
3479 and discard the oldest trace frames instead of stopping the trace due
3480 to a full trace buffer. If set to off, the trace stops when the buffer
3481 fills up. Some targets may not support this.
3483 set script-extension off|soft|strict
3484 show script-extension
3485 If set to "off", the debugger does not perform any script language
3486 recognition, and all sourced files are assumed to be GDB scripts.
3487 If set to "soft" (the default), files are sourced according to
3488 filename extension, falling back to GDB scripts if the first
3490 If set to "strict", files are sourced according to filename extension.
3492 set ada trust-PAD-over-XVS on|off
3493 show ada trust-PAD-over-XVS
3494 If off, activate a workaround against a bug in the debugging information
3495 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3496 the GCC sources for more information about the GNAT encoding and
3497 PAD types in particular). It is always safe to set this option to
3498 off, but this introduces a slight performance penalty. The default
3501 * Python API Improvements
3503 ** GDB provides the new class gdb.LazyString. This is useful in
3504 some pretty-printing cases. The new method gdb.Value.lazy_string
3505 provides a simple way to create objects of this type.
3507 ** The fields returned by gdb.Type.fields now have an
3508 `is_base_class' attribute.
3510 ** The new method gdb.Type.range returns the range of an array type.
3512 ** The new method gdb.parse_and_eval can be used to parse and
3513 evaluate an expression.
3515 * New remote packets
3518 Define a trace state variable.
3521 Get the current value of a trace state variable.
3524 Set desired tracing behavior upon disconnection.
3527 Set the trace buffer to be linear or circular.
3530 Get data about the tracepoints currently in use.
3534 Process record now works correctly with hardware watchpoints.
3536 Multiple bug fixes have been made to the mips-irix port, making it
3537 much more reliable. In particular:
3538 - Debugging threaded applications is now possible again. Previously,
3539 GDB would hang while starting the program, or while waiting for
3540 the program to stop at a breakpoint.
3541 - Attaching to a running process no longer hangs.
3542 - An error occurring while loading a core file has been fixed.
3543 - Changing the value of the PC register now works again. This fixes
3544 problems observed when using the "jump" command, or when calling
3545 a function from GDB, or even when assigning a new value to $pc.
3546 - With the "finish" and "return" commands, the return value for functions
3547 returning a small array is now correctly printed.
3548 - It is now possible to break on shared library code which gets executed
3549 during a shared library init phase (code executed while executing
3550 their .init section). Previously, the breakpoint would have no effect.
3551 - GDB is now able to backtrace through the signal handler for
3552 non-threaded programs.
3554 PIE (Position Independent Executable) programs debugging is now supported.
3555 This includes debugging execution of PIC (Position Independent Code) shared
3556 libraries although for that, it should be possible to run such libraries as an
3559 *** Changes in GDB 7.0
3561 * GDB now has an interface for JIT compilation. Applications that
3562 dynamically generate code can create symbol files in memory and register
3563 them with GDB. For users, the feature should work transparently, and
3564 for JIT developers, the interface is documented in the GDB manual in the
3565 "JIT Compilation Interface" chapter.
3567 * Tracepoints may now be conditional. The syntax is as for
3568 breakpoints; either an "if" clause appended to the "trace" command,
3569 or the "condition" command is available. GDB sends the condition to
3570 the target for evaluation using the same bytecode format as is used
3571 for tracepoint actions.
3573 * The disassemble command now supports: an optional /r modifier, print the
3574 raw instructions in hex as well as in symbolic form, and an optional /m
3575 modifier to print mixed source+assembly.
3577 * Process record and replay
3579 In a architecture environment that supports ``process record and
3580 replay'', ``process record and replay'' target can record a log of
3581 the process execution, and replay it with both forward and reverse
3584 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3585 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3586 set execution-direction {forward|reverse}, for targets that support
3589 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3590 feature is available with a native GDB running on kernel version
3593 * GDB now has support for multi-byte and wide character sets on the
3594 target. Strings whose character type is wchar_t, char16_t, or
3595 char32_t are now correctly printed. GDB supports wide- and unicode-
3596 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3597 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3598 `printf'. This feature requires iconv to work properly; if your
3599 system does not have a working iconv, GDB can use GNU libiconv. See
3600 the installation instructions for more information.
3602 * GDB now supports automatic retrieval of shared library files from
3603 remote targets. To use this feature, specify a system root that begins
3604 with the `remote:' prefix, either via the `set sysroot' command or via
3605 the `--with-sysroot' configure-time option.
3607 * "info sharedlibrary" now takes an optional regex of libraries to show,
3608 and it now reports if a shared library has no debugging information.
3610 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3611 now complete on file names.
3613 * When completing in expressions, gdb will attempt to limit
3614 completions to allowable structure or union fields, where appropriate.
3615 For instance, consider:
3617 # struct example { int f1; double f2; };
3618 # struct example variable;
3621 If the user types TAB at the end of this command line, the available
3622 completions will be "f1" and "f2".
3624 * Inlined functions are now supported. They show up in backtraces, and
3625 the "step", "next", and "finish" commands handle them automatically.
3627 * GDB now supports the token-splicing (##) and stringification (#)
3628 operators when expanding macros. It also supports variable-arity
3631 * GDB now supports inspecting extra signal information, exported by
3632 the new $_siginfo convenience variable. The feature is currently
3633 implemented on linux ARM, i386 and amd64.
3635 * GDB can now display the VFP floating point registers and NEON vector
3636 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3637 can provide these registers (requires Linux 2.6.30 or later). Remote
3638 and simulator targets may also provide them.
3640 * New remote packets
3643 Search memory for a sequence of bytes.
3646 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3647 operation over reliable transport links. Use of this packet is
3648 controlled by the `set remote noack-packet' command.
3651 Kill the process with the specified process ID. Use this in preference
3652 to `k' when multiprocess protocol extensions are supported.
3655 Obtains additional operating system information
3659 Read or write additional signal information.
3661 * Removed remote protocol undocumented extension
3663 An undocumented extension to the remote protocol's `S' stop reply
3664 packet that permited the stub to pass a process id was removed.
3665 Remote servers should use the `T' stop reply packet instead.
3667 * GDB now supports multiple function calling conventions according to the
3668 DWARF-2 DW_AT_calling_convention function attribute.
3670 * The SH target utilizes the aforementioned change to distinguish between gcc
3671 and Renesas calling convention. It also adds the new CLI commands
3672 `set/show sh calling-convention'.
3674 * GDB can now read compressed debug sections, as produced by GNU gold
3675 with the --compress-debug-sections=zlib flag.
3677 * 64-bit core files are now supported on AIX.
3679 * Thread switching is now supported on Tru64.
3681 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3682 which will be allocated using malloc later in program execution.
3684 * The qXfer:libraries:read remote procotol packet now allows passing a
3685 list of section offsets.
3687 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3688 conditions handling signals delivered during attach or thread creation
3689 have also been fixed.
3691 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3692 From the user's standpoint, all unqualified instances of True and False
3693 are treated as the standard definitions, regardless of context.
3695 * GDB now parses C++ symbol and type names more flexibly. For
3698 template<typename T> class C { };
3701 GDB will now correctly handle all of:
3703 ptype C<char const *>
3704 ptype C<char const*>
3705 ptype C<const char *>
3706 ptype C<const char*>
3708 * New features in the GDB remote stub, gdbserver
3710 - The "--wrapper" command-line argument tells gdbserver to use a
3711 wrapper program to launch programs for debugging.
3713 - On PowerPC and S/390 targets, it is now possible to use a single
3714 gdbserver executable to debug both 32-bit and 64-bit programs.
3715 (This requires gdbserver itself to be built as a 64-bit executable.)
3717 - gdbserver uses the new noack protocol mode for TCP connections to
3718 reduce communications latency, if also supported and enabled in GDB.
3720 - Support for the sparc64-linux-gnu target is now included in
3723 - The amd64-linux build of gdbserver now supports debugging both
3724 32-bit and 64-bit programs.
3726 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3727 now support hardware watchpoints, and will use them automatically
3732 GDB now has support for scripting using Python. Whether this is
3733 available is determined at configure time.
3735 New GDB commands can now be written in Python.
3737 * Ada tasking support
3739 Ada tasks can now be inspected in GDB. The following commands have
3743 Print the list of Ada tasks.
3745 Print detailed information about task number N.
3747 Print the task number of the current task.
3749 Switch the context of debugging to task number N.
3751 * Support for user-defined prefixed commands. The "define" command can
3752 add new commands to existing prefixes, e.g. "target".
3754 * Multi-inferior, multi-process debugging.
3756 GDB now has generalized support for multi-inferior debugging. See
3757 "Debugging Multiple Inferiors" in the manual for more information.
3758 Although availability still depends on target support, the command
3759 set is more uniform now. The GNU/Linux specific multi-forks support
3760 has been migrated to this new framework. This implied some user
3761 visible changes; see "New commands" and also "Removed commands"
3764 * Target descriptions can now describe the target OS ABI. See the
3765 "Target Description Format" section in the user manual for more
3768 * Target descriptions can now describe "compatible" architectures
3769 to indicate that the target can execute applications for a different
3770 architecture in addition to those for the main target architecture.
3771 See the "Target Description Format" section in the user manual for
3774 * Multi-architecture debugging.
3776 GDB now includes general supports for debugging applications on
3777 hybrid systems that use more than one single processor architecture
3778 at the same time. Each such hybrid architecture still requires
3779 specific support to be added. The only hybrid architecture supported
3780 in this version of GDB is the Cell Broadband Engine.
3782 * GDB now supports integrated debugging of Cell/B.E. applications that
3783 use both the PPU and SPU architectures. To enable support for hybrid
3784 Cell/B.E. debugging, you need to configure GDB to support both the
3785 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3786 --enable-targets configure option.
3788 * Non-stop mode debugging.
3790 For some targets, GDB now supports an optional mode of operation in
3791 which you can examine stopped threads while other threads continue
3792 to execute freely. This is referred to as non-stop mode, with the
3793 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3794 section in the user manual for more information.
3796 To be able to support remote non-stop debugging, a remote stub needs
3797 to implement the non-stop mode remote protocol extensions, as
3798 described in the "Remote Non-Stop" section of the user manual. The
3799 GDB remote stub, gdbserver, has been adjusted to support these
3800 extensions on linux targets.
3802 * New commands (for set/show, see "New options" below)
3804 catch syscall [NAME(S) | NUMBER(S)]
3805 Catch system calls. Arguments, which should be names of system
3806 calls or their numbers, mean catch only those syscalls. Without
3807 arguments, every syscall will be caught. When the inferior issues
3808 any of the specified syscalls, GDB will stop and announce the system
3809 call, both when it is called and when its call returns. This
3810 feature is currently available with a native GDB running on the
3811 Linux Kernel, under the following architectures: x86, x86_64,
3812 PowerPC and PowerPC64.
3814 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3816 Search memory for a sequence of bytes.
3818 maint set python print-stack
3819 maint show python print-stack
3820 Show a stack trace when an error is encountered in a Python script.
3823 Invoke CODE by passing it to the Python interpreter.
3828 These allow macros to be defined, undefined, and listed
3832 Show operating system information about processes.
3835 List the inferiors currently under GDB's control.
3838 Switch focus to inferior number NUM.
3841 Detach from inferior number NUM.
3844 Kill inferior number NUM.
3848 set spu stop-on-load
3849 show spu stop-on-load
3850 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3852 set spu auto-flush-cache
3853 show spu auto-flush-cache
3854 Control whether to automatically flush the software-managed cache
3855 during Cell/B.E. debugging.
3857 set sh calling-convention
3858 show sh calling-convention
3859 Control the calling convention used when calling SH target functions.
3862 show debug timestamp
3863 Control display of timestamps with GDB debugging output.
3865 set disassemble-next-line
3866 show disassemble-next-line
3867 Control display of disassembled source lines or instructions when
3870 set remote noack-packet
3871 show remote noack-packet
3872 Set/show the use of remote protocol QStartNoAckMode packet. See above
3873 under "New remote packets."
3875 set remote query-attached-packet
3876 show remote query-attached-packet
3877 Control use of remote protocol `qAttached' (query-attached) packet.
3879 set remote read-siginfo-object
3880 show remote read-siginfo-object
3881 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3884 set remote write-siginfo-object
3885 show remote write-siginfo-object
3886 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3889 set remote reverse-continue
3890 show remote reverse-continue
3891 Control use of remote protocol 'bc' (reverse-continue) packet.
3893 set remote reverse-step
3894 show remote reverse-step
3895 Control use of remote protocol 'bs' (reverse-step) packet.
3897 set displaced-stepping
3898 show displaced-stepping
3899 Control displaced stepping mode. Displaced stepping is a way to
3900 single-step over breakpoints without removing them from the debuggee.
3901 Also known as "out-of-line single-stepping".
3904 show debug displaced
3905 Control display of debugging info for displaced stepping.
3907 maint set internal-error
3908 maint show internal-error
3909 Control what GDB does when an internal error is detected.
3911 maint set internal-warning
3912 maint show internal-warning
3913 Control what GDB does when an internal warning is detected.
3918 Use a wrapper program to launch programs for debugging.
3920 set multiple-symbols (all|ask|cancel)
3921 show multiple-symbols
3922 The value of this variable can be changed to adjust the debugger behavior
3923 when an expression or a breakpoint location contains an ambiguous symbol
3924 name (an overloaded function name, for instance).
3926 set breakpoint always-inserted
3927 show breakpoint always-inserted
3928 Keep breakpoints always inserted in the target, as opposed to inserting
3929 them when resuming the target, and removing them when the target stops.
3930 This option can improve debugger performance on slow remote targets.
3932 set arm fallback-mode (arm|thumb|auto)
3933 show arm fallback-mode
3934 set arm force-mode (arm|thumb|auto)
3936 These commands control how ARM GDB determines whether instructions
3937 are ARM or Thumb. The default for both settings is auto, which uses
3938 the current CPSR value for instructions without symbols; previous
3939 versions of GDB behaved as if "set arm fallback-mode arm".
3941 set disable-randomization
3942 show disable-randomization
3943 Standalone programs run with the virtual address space randomization enabled
3944 by default on some platforms. This option keeps the addresses stable across
3945 multiple debugging sessions.
3949 Control whether other threads are stopped or not when some thread hits
3954 Requests that asynchronous execution is enabled in the target, if available.
3955 In this case, it's possible to resume target in the background, and interact
3956 with GDB while the target is running. "show target-async" displays the
3957 current state of asynchronous execution of the target.
3959 set target-wide-charset
3960 show target-wide-charset
3961 The target-wide-charset is the name of the character set that GDB
3962 uses when printing characters whose type is wchar_t.
3964 set tcp auto-retry (on|off)
3966 set tcp connect-timeout
3967 show tcp connect-timeout
3968 These commands allow GDB to retry failed TCP connections to a remote stub
3969 with a specified timeout period; this is useful if the stub is launched
3970 in parallel with GDB but may not be ready to accept connections immediately.
3972 set libthread-db-search-path
3973 show libthread-db-search-path
3974 Control list of directories which GDB will search for appropriate
3977 set schedule-multiple (on|off)
3978 show schedule-multiple
3979 Allow GDB to resume all threads of all processes or only threads of
3980 the current process.
3984 Use more aggressive caching for accesses to the stack. This improves
3985 performance of remote debugging (particularly backtraces) without
3986 affecting correctness.
3988 set interactive-mode (on|off|auto)
3989 show interactive-mode
3990 Control whether GDB runs in interactive mode (on) or not (off).
3991 When in interactive mode, GDB waits for the user to answer all
3992 queries. Otherwise, GDB does not wait and assumes the default
3993 answer. When set to auto (the default), GDB determines which
3994 mode to use based on the stdin settings.
3999 For program forks, this is replaced by the new more generic `info
4000 inferiors' command. To list checkpoints, you can still use the
4001 `info checkpoints' command, which was an alias for the `info forks'
4005 Replaced by the new `inferior' command. To switch between
4006 checkpoints, you can still use the `restart' command, which was an
4007 alias for the `fork' command.
4010 This is removed, since some targets don't have a notion of
4011 processes. To switch between processes, you can still use the
4012 `inferior' command using GDB's own inferior number.
4015 For program forks, this is replaced by the new more generic `kill
4016 inferior' command. To delete a checkpoint, you can still use the
4017 `delete checkpoint' command, which was an alias for the `delete
4021 For program forks, this is replaced by the new more generic `detach
4022 inferior' command. To detach a checkpoint, you can still use the
4023 `detach checkpoint' command, which was an alias for the `detach
4026 * New native configurations
4028 x86/x86_64 Darwin i[34567]86-*-darwin*
4030 x86_64 MinGW x86_64-*-mingw*
4034 Lattice Mico32 lm32-*
4035 x86 DICOS i[34567]86-*-dicos*
4036 x86_64 DICOS x86_64-*-dicos*
4039 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4040 (mingw32ce) debugging.
4046 These commands were actually not implemented on any target.
4048 *** Changes in GDB 6.8
4050 * New native configurations
4052 NetBSD/hppa hppa*-*netbsd*
4053 Xtensa GNU/Linux xtensa*-*-linux*
4057 NetBSD/hppa hppa*-*-netbsd*
4058 Xtensa GNU/Lunux xtensa*-*-linux*
4060 * Change in command line behavior -- corefiles vs. process ids.
4062 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4063 attaching to process NUMBER fails, GDB no longer attempts to open a
4064 core file named NUMBER. Attaching to a program using the -c option
4065 is no longer supported. Instead, use the '-p' or '--pid' options.
4067 * GDB can now be built as a native debugger for debugging Windows x86
4068 (mingw32) Portable Executable (PE) programs.
4070 * Pending breakpoints no longer change their number when their address
4073 * GDB now supports breakpoints with multiple locations,
4074 including breakpoints on C++ constructors, inside C++ templates,
4075 and in inlined functions.
4077 * GDB's ability to debug optimized code has been improved. GDB more
4078 accurately identifies function bodies and lexical blocks that occupy
4079 more than one contiguous range of addresses.
4081 * Target descriptions can now describe registers for PowerPC.
4083 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4084 registers on PowerPC targets.
4086 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4087 targets even when the libthread_db library is not available.
4089 * The GDB remote stub, gdbserver, now supports the new file transfer
4090 commands (remote put, remote get, and remote delete).
4092 * The GDB remote stub, gdbserver, now supports run and attach in
4093 extended-remote mode.
4095 * hppa*64*-*-hpux11* target broken
4096 The debugger is unable to start a program and fails with the following
4097 error: "Error trying to get information about dynamic linker".
4098 The gdb-6.7 release is also affected.
4100 * GDB now supports the --enable-targets= configure option to allow
4101 building a single GDB executable that supports multiple remote
4102 target architectures.
4104 * GDB now supports debugging C and C++ programs which use the
4105 Decimal Floating Point extension. In addition, the PowerPC target
4106 now has a set of pseudo-registers to inspect decimal float values
4107 stored in two consecutive float registers.
4109 * The -break-insert MI command can optionally create pending
4112 * Improved support for debugging Ada
4113 Many improvements to the Ada language support have been made. These
4115 - Better support for Ada2005 interface types
4116 - Improved handling of arrays and slices in general
4117 - Better support for Taft-amendment types
4118 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4120 - Improved command completion in Ada
4123 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4128 set print frame-arguments (all|scalars|none)
4129 show print frame-arguments
4130 The value of this variable can be changed to control which argument
4131 values should be printed by the debugger when displaying a frame.
4136 Transfer files to and from a remote target, and delete remote files.
4143 Transfer files to and from a remote target, and delete remote files.
4145 * New remote packets
4152 Open, close, read, write, and delete files on the remote system.
4155 Attach to an existing process on the remote system, in extended-remote
4159 Run a new process on the remote system, in extended-remote mode.
4161 *** Changes in GDB 6.7
4163 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4164 bfd, libiberty and opcodes, as revealed by static analysis donated by
4165 Coverity, Inc. (http://scan.coverity.com).
4167 * When looking up multiply-defined global symbols, GDB will now prefer the
4168 symbol definition in the current shared library if it was built using the
4169 -Bsymbolic linker option.
4171 * When the Text User Interface (TUI) is not configured, GDB will now
4172 recognize the -tui command-line option and print a message that the TUI
4175 * The GDB remote stub, gdbserver, now has lower overhead for high
4176 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4178 * GDB for MIPS targets now autodetects whether a remote target provides
4179 32-bit or 64-bit register values.
4181 * Support for C++ member pointers has been improved.
4183 * GDB now understands XML target descriptions, which specify the
4184 target's overall architecture. GDB can read a description from
4185 a local file or over the remote serial protocol.
4187 * Vectors of single-byte data use a new integer type which is not
4188 automatically displayed as character or string data.
4190 * The /s format now works with the print command. It displays
4191 arrays of single-byte integers and pointers to single-byte integers
4194 * Target descriptions can now describe target-specific registers,
4195 for architectures which have implemented the support (currently
4196 only ARM, M68K, and MIPS).
4198 * GDB and the GDB remote stub, gdbserver, now support the XScale
4201 * The GDB remote stub, gdbserver, has been updated to support
4202 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4203 has been rewritten to use the standard GDB remote protocol.
4205 * GDB can now step into C++ functions which are called through thunks.
4207 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4209 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4210 layout. It also supports a TextSeg= and DataSeg= response when only
4211 segment base addresses (rather than offsets) are available.
4213 * The /i format now outputs any trailing branch delay slot instructions
4214 immediately following the last instruction within the count specified.
4216 * The GDB remote protocol "T" stop reply packet now supports a
4217 "library" response. Combined with the new "qXfer:libraries:read"
4218 packet, this response allows GDB to debug shared libraries on targets
4219 where the operating system manages the list of loaded libraries (e.g.
4220 Windows and SymbianOS).
4222 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4223 (DLLs) on Windows and Windows CE targets.
4225 * GDB now supports a faster verification that a .debug file matches its binary
4226 according to its build-id signature, if the signature is present.
4232 Enable or disable hardware flow control (RTS/CTS) on the serial port
4233 when debugging using remote targets.
4235 set mem inaccessible-by-default
4236 show mem inaccessible-by-default
4237 If the target supplies a memory map, for instance via the remote
4238 protocol's "qXfer:memory-map:read" packet, setting this variable
4239 prevents GDB from accessing memory outside the memory map. This
4240 is useful for targets with memory mapped registers or which react
4241 badly to accesses of unmapped address space.
4243 set breakpoint auto-hw
4244 show breakpoint auto-hw
4245 If the target supplies a memory map, for instance via the remote
4246 protocol's "qXfer:memory-map:read" packet, setting this variable
4247 lets GDB use hardware breakpoints automatically for memory regions
4248 where it can not use software breakpoints. This covers both the
4249 "break" command and internal breakpoints used for other commands
4250 including "next" and "finish".
4253 catch exception unhandled
4254 Stop the program execution when Ada exceptions are raised.
4257 Stop the program execution when an Ada assertion failed.
4261 Set an alternate system root for target files. This is a more
4262 general version of "set solib-absolute-prefix", which is now
4263 an alias to "set sysroot".
4266 Provide extended SPU facility status information. This set of
4267 commands is available only when debugging the Cell/B.E. SPU
4270 * New native configurations
4272 OpenBSD/sh sh*-*openbsd*
4275 unset tdesc filename
4277 Use the specified local file as an XML target description, and do
4278 not query the target for its built-in description.
4282 OpenBSD/sh sh*-*-openbsd*
4283 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4284 Toshiba Media Processor mep-elf
4286 * New remote packets
4289 Ignore the specified signals; pass them directly to the debugged program
4290 without stopping other threads or reporting them to GDB.
4292 qXfer:features:read:
4293 Read an XML target description from the target, which describes its
4298 Read or write contents of an spufs file on the target system. These
4299 packets are available only on the Cell/B.E. SPU architecture.
4301 qXfer:libraries:read:
4302 Report the loaded shared libraries. Combined with new "T" packet
4303 response, this packet allows GDB to debug shared libraries on
4304 targets where the operating system manages the list of loaded
4305 libraries (e.g. Windows and SymbianOS).
4309 Support for these obsolete configurations has been removed.
4317 i[34567]86-*-lynxos*
4318 i[34567]86-*-netware*
4319 i[34567]86-*-sco3.2v5*
4320 i[34567]86-*-sco3.2v4*
4322 i[34567]86-*-sysv4.2*
4325 i[34567]86-*-unixware2*
4326 i[34567]86-*-unixware*
4335 * Other removed features
4342 Various m68k-only ROM monitors.
4349 Various Renesas ROM monitors and debugging interfaces for SH and
4354 Support for a Macraigor serial interface to on-chip debugging.
4355 GDB does not directly support the newer parallel or USB
4360 A debug information format. The predecessor to DWARF 2 and
4361 DWARF 3, which are still supported.
4363 Support for the HP aCC compiler on HP-UX/PA-RISC
4365 SOM-encapsulated symbolic debugging information, automatic
4366 invocation of pxdb, and the aCC custom C++ ABI. This does not
4367 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4368 with aCC can still be debugged on an assembly level.
4370 MIPS ".pdr" sections
4372 A MIPS-specific format used to describe stack frame layout
4373 in debugging information.
4377 GDB could work with an older version of Guile to debug
4378 the interpreter and Scheme programs running in it.
4380 set mips stack-arg-size
4381 set mips saved-gpreg-size
4383 Use "set mips abi" to control parameter passing for MIPS.
4385 *** Changes in GDB 6.6
4390 Cell Broadband Engine SPU spu-elf
4392 * GDB can now be configured as a cross-debugger targeting native Windows
4393 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4394 running on a Windows system over TCP/IP to debug Windows programs.
4396 * The GDB remote stub, gdbserver, has been updated to support Windows and
4397 Cygwin debugging. Both single-threaded and multi-threaded programs are
4400 * The "set trust-readonly-sections" command works again. This command was
4401 broken in GDB 6.3, 6.4, and 6.5.
4403 * The "load" command now supports writing to flash memory, if the remote
4404 stub provides the required support.
4406 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4407 longer requires symbolic debug information (e.g. DWARF-2).
4412 unset substitute-path
4413 show substitute-path
4414 Manage a list of substitution rules that GDB uses to rewrite the name
4415 of the directories where the sources are located. This can be useful
4416 for instance when the sources were moved to a different location
4417 between compilation and debugging.
4421 Print each CLI command as it is executed. Each command is prefixed with
4422 a number of `+' symbols representing the nesting depth.
4423 The source command now has a `-v' option to enable the same feature.
4427 The ARM Demon monitor support (RDP protocol, "target rdp").
4429 Kernel Object Display, an embedded debugging feature which only worked with
4430 an obsolete version of Cisco IOS.
4432 The 'set download-write-size' and 'show download-write-size' commands.
4434 * New remote packets
4437 Tell a stub about GDB client features, and request remote target features.
4438 The first feature implemented is PacketSize, which allows the target to
4439 specify the size of packets it can handle - to minimize the number of
4440 packets required and improve performance when connected to a remote
4444 Fetch an OS auxilliary vector from the remote stub. This packet is a
4445 more efficient replacement for qPart:auxv:read.
4447 qXfer:memory-map:read:
4448 Fetch a memory map from the remote stub, including information about
4449 RAM, ROM, and flash memory devices.
4454 Erase and program a flash memory device.
4456 * Removed remote packets
4459 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4460 used it, and only gdbserver implemented it.
4462 *** Changes in GDB 6.5
4466 Renesas M32C/M16C m32c-elf
4468 Morpho Technologies ms1 ms1-elf
4472 init-if-undefined Initialize a convenience variable, but
4473 only if it doesn't already have a value.
4475 The following commands are presently only implemented for native GNU/Linux:
4477 checkpoint Save a snapshot of the program state.
4479 restart <n> Return the program state to a
4480 previously saved state.
4482 info checkpoints List currently saved checkpoints.
4484 delete-checkpoint <n> Delete a previously saved checkpoint.
4486 set|show detach-on-fork Tell gdb whether to detach from a newly
4487 forked process, or to keep debugging it.
4489 info forks List forks of the user program that
4490 are available to be debugged.
4492 fork <n> Switch to debugging one of several
4493 forks of the user program that are
4494 available to be debugged.
4496 delete-fork <n> Delete a fork from the list of forks
4497 that are available to be debugged (and
4498 kill the forked process).
4500 detach-fork <n> Delete a fork from the list of forks
4501 that are available to be debugged (and
4502 allow the process to continue).
4506 Morpho Technologies ms2 ms1-elf
4508 * Improved Windows host support
4510 GDB now builds as a cross debugger hosted on i686-mingw32, including
4511 native console support, and remote communications using either
4512 network sockets or serial ports.
4514 * Improved Modula-2 language support
4516 GDB can now print most types in the Modula-2 syntax. This includes:
4517 basic types, set types, record types, enumerated types, range types,
4518 pointer types and ARRAY types. Procedure var parameters are correctly
4519 printed and hexadecimal addresses and character constants are also
4520 written in the Modula-2 syntax. Best results can be obtained by using
4521 GNU Modula-2 together with the -gdwarf-2 command line option.
4525 The ARM rdi-share module.
4527 The Netware NLM debug server.
4529 *** Changes in GDB 6.4
4531 * New native configurations
4533 OpenBSD/arm arm*-*-openbsd*
4534 OpenBSD/mips64 mips64-*-openbsd*
4538 Morpho Technologies ms1 ms1-elf
4540 * New command line options
4542 --batch-silent As for --batch, but totally silent.
4543 --return-child-result The debugger will exist with the same value
4544 the child (debugged) program exited with.
4545 --eval-command COMMAND, -ex COMMAND
4546 Execute a single GDB CLI command. This may be
4547 specified multiple times and in conjunction
4548 with the --command (-x) option.
4550 * Deprecated commands removed
4552 The following commands, that were deprecated in 2000, have been
4556 set|show arm disassembly-flavor set|show arm disassembler
4557 othernames set arm disassembler
4558 set|show remotedebug set|show debug remote
4559 set|show archdebug set|show debug arch
4560 set|show eventdebug set|show debug event
4563 * New BSD user-level threads support
4565 It is now possible to debug programs using the user-level threads
4566 library on OpenBSD and FreeBSD. Currently supported (target)
4569 FreeBSD/amd64 x86_64-*-freebsd*
4570 FreeBSD/i386 i386-*-freebsd*
4571 OpenBSD/i386 i386-*-openbsd*
4573 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4574 are not yet supported.
4576 * New support for Matsushita MN10300 w/sim added
4577 (Work in progress). mn10300-elf.
4579 * REMOVED configurations and files
4581 VxWorks and the XDR protocol *-*-vxworks
4582 Motorola MCORE mcore-*-*
4583 National Semiconductor NS32000 ns32k-*-*
4585 * New "set print array-indexes" command
4587 After turning this setting "on", GDB prints the index of each element
4588 when displaying arrays. The default is "off" to preserve the previous
4591 * VAX floating point support
4593 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4595 * User-defined command support
4597 In addition to using $arg0..$arg9 for argument passing, it is now possible
4598 to use $argc to determine now many arguments have been passed. See the
4599 section on user-defined commands in the user manual for more information.
4601 *** Changes in GDB 6.3:
4603 * New command line option
4605 GDB now accepts -l followed by a number to set the timeout for remote
4608 * GDB works with GCC -feliminate-dwarf2-dups
4610 GDB now supports a more compact representation of DWARF-2 debug
4611 information using DW_FORM_ref_addr references. These are produced
4612 by GCC with the option -feliminate-dwarf2-dups and also by some
4613 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4614 to use -feliminate-dwarf2-dups.
4616 * Internationalization
4618 When supported by the host system, GDB will be built with
4619 internationalization (libintl). The task of marking up the sources is
4620 continued, we're looking forward to our first translation.
4624 Initial support for debugging programs compiled with the GNAT
4625 implementation of the Ada programming language has been integrated
4626 into GDB. In this release, support is limited to expression evaluation.
4628 * New native configurations
4630 GNU/Linux/m32r m32r-*-linux-gnu
4634 GDB's remote protocol now includes support for the 'p' packet. This
4635 packet is used to fetch individual registers from a remote inferior.
4637 * END-OF-LIFE registers[] compatibility module
4639 GDB's internal register infrastructure has been completely rewritten.
4640 The new infrastructure making possible the implementation of key new
4641 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4644 GDB 6.3 will be the last release to include the the registers[]
4645 compatibility module that allowed out-of-date configurations to
4646 continue to work. This change directly impacts the following
4656 powerpc bdm protocol
4658 Unless there is activity to revive these configurations, they will be
4659 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4661 * OBSOLETE configurations and files
4663 Configurations that have been declared obsolete in this release have
4664 been commented out. Unless there is activity to revive these
4665 configurations, the next release of GDB will have their sources
4666 permanently REMOVED.
4675 *** Changes in GDB 6.2.1:
4677 * MIPS `break main; run' gave an heuristic-fence-post warning
4679 When attempting to run even a simple program, a warning about
4680 heuristic-fence-post being hit would be reported. This problem has
4683 * MIPS IRIX 'long double' crashed GDB
4685 When examining a long double variable, GDB would get a segmentation
4686 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4687 IRIX long double values).
4691 A bug in the VAX stack code was causing problems with the "next"
4692 command. This problem has been fixed.
4694 *** Changes in GDB 6.2:
4696 * Fix for ``many threads''
4698 On GNU/Linux systems that use the NPTL threads library, a program
4699 rapidly creating and deleting threads would confuse GDB leading to the
4702 ptrace: No such process.
4703 thread_db_get_info: cannot get thread info: generic error
4705 This problem has been fixed.
4707 * "-async" and "-noasync" options removed.
4709 Support for the broken "-noasync" option has been removed (it caused
4712 * New ``start'' command.
4714 This command runs the program until the begining of the main procedure.
4716 * New BSD Kernel Data Access Library (libkvm) interface
4718 Using ``target kvm'' it is now possible to debug kernel core dumps and
4719 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4720 platforms. Currently supported (native-only) configurations are:
4722 FreeBSD/amd64 x86_64-*-freebsd*
4723 FreeBSD/i386 i?86-*-freebsd*
4724 NetBSD/i386 i?86-*-netbsd*
4725 NetBSD/m68k m68*-*-netbsd*
4726 NetBSD/sparc sparc-*-netbsd*
4727 OpenBSD/amd64 x86_64-*-openbsd*
4728 OpenBSD/i386 i?86-*-openbsd*
4729 OpenBSD/m68k m68*-openbsd*
4730 OpenBSD/sparc sparc-*-openbsd*
4732 * Signal trampoline code overhauled
4734 Many generic problems with GDB's signal handling code have been fixed.
4735 These include: backtraces through non-contiguous stacks; recognition
4736 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4737 call; backtrace through a signal trampoline; step into and out of
4738 signal handlers; and single-stepping in the signal trampoline.
4740 Please note that kernel bugs are a limiting factor here. These
4741 features have been shown to work on an s390 GNU/Linux system that
4742 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4744 * Cygwin support for DWARF 2 added.
4746 * New native configurations
4748 GNU/Linux/hppa hppa*-*-linux*
4749 OpenBSD/hppa hppa*-*-openbsd*
4750 OpenBSD/m68k m68*-*-openbsd*
4751 OpenBSD/m88k m88*-*-openbsd*
4752 OpenBSD/powerpc powerpc-*-openbsd*
4753 NetBSD/vax vax-*-netbsd*
4754 OpenBSD/vax vax-*-openbsd*
4756 * END-OF-LIFE frame compatibility module
4758 GDB's internal frame infrastructure has been completely rewritten.
4759 The new infrastructure making it possible to support key new features
4760 including DWARF 2 Call Frame Information. To aid in the task of
4761 migrating old configurations to this new infrastructure, a
4762 compatibility module, that allowed old configurations to continue to
4763 work, was also included.
4765 GDB 6.2 will be the last release to include this frame compatibility
4766 module. This change directly impacts the following configurations:
4776 Unless there is activity to revive these configurations, they will be
4777 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4779 * REMOVED configurations and files
4781 Sun 3, running SunOS 3 m68*-*-sunos3*
4782 Sun 3, running SunOS 4 m68*-*-sunos4*
4783 Sun 2, running SunOS 3 m68000-*-sunos3*
4784 Sun 2, running SunOS 4 m68000-*-sunos4*
4785 Motorola 680x0 running LynxOS m68*-*-lynxos*
4786 AT&T 3b1/Unix pc m68*-att-*
4787 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4788 decstation mips-dec-* mips-little-*
4789 riscos mips-*-riscos* mips-*-sysv*
4790 sonymips mips-sony-*
4791 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4793 *** Changes in GDB 6.1.1:
4795 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4797 The TUI (Text-mode User Interface) is now built as part of a default
4798 GDB configuration. It is enabled by either selecting the TUI with the
4799 command line option "-i=tui" or by running the separate "gdbtui"
4800 program. For more information on the TUI, see the manual "Debugging
4803 * Pending breakpoint support (also included in GDB 6.1)
4805 Support has been added to allow you to specify breakpoints in shared
4806 libraries that have not yet been loaded. If a breakpoint location
4807 cannot be found, and the "breakpoint pending" option is set to auto,
4808 GDB queries you if you wish to make the breakpoint pending on a future
4809 shared-library load. If and when GDB resolves the breakpoint symbol,
4810 the pending breakpoint is removed as one or more regular breakpoints
4813 Pending breakpoints are very useful for GCJ Java debugging.
4815 * Fixed ISO-C build problems
4817 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4818 non ISO-C code that stopped them being built using a more strict ISO-C
4819 compiler (e.g., IBM's C compiler).
4821 * Fixed build problem on IRIX 5
4823 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4824 wasn't able to compile compile on an IRIX 5 system.
4826 * Added execute permission to gdb/gdbserver/configure
4828 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4829 permission. This bug would cause configure to fail on a number of
4830 systems (Solaris, IRIX). Ref: server/519.
4832 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4834 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4835 has been updated to use constant array sizes.
4837 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4839 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4840 its generated DWARF Call Frame Info. This encoding was causing GDB to
4841 panic, that panic has been fixed. Ref: gdb/1628.
4843 * Fixed a problem when examining parameters in shared library code.
4845 When examining parameters in optimized shared library code generated
4846 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4847 not available''. GDB now correctly displays the variable's value.
4849 *** Changes in GDB 6.1:
4851 * Removed --with-mmalloc
4853 Support for the mmalloc memory manager has been removed, as it
4854 conflicted with the internal gdb byte cache.
4856 * Changes in AMD64 configurations
4858 The AMD64 target now includes the %cs and %ss registers. As a result
4859 the AMD64 remote protocol has changed; this affects the floating-point
4860 and SSE registers. If you rely on those registers for your debugging,
4861 you should upgrade gdbserver on the remote side.
4863 * Revised SPARC target
4865 The SPARC target has been completely revised, incorporating the
4866 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4867 support for LynxOS and SunOS 4 has been dropped. Calling functions
4868 from within GDB on operating systems with a non-executable stack
4869 (Solaris, OpenBSD) now works.
4873 GDB has a new C++ demangler which does a better job on the mangled
4874 names generated by current versions of g++. It also runs faster, so
4875 with this and other changes gdb should now start faster on large C++
4878 * DWARF 2 Location Expressions
4880 GDB support for location expressions has been extended to support function
4881 arguments and frame bases. Older versions of GDB could crash when they
4884 * C++ nested types and namespaces
4886 GDB's support for nested types and namespaces in C++ has been
4887 improved, especially if you use the DWARF 2 debugging format. (This
4888 is the default for recent versions of GCC on most platforms.)
4889 Specifically, if you have a class "Inner" defined within a class or
4890 namespace "Outer", then GDB realizes that the class's name is
4891 "Outer::Inner", not simply "Inner". This should greatly reduce the
4892 frequency of complaints about not finding RTTI symbols. In addition,
4893 if you are stopped at inside of a function defined within a namespace,
4894 GDB modifies its name lookup accordingly.
4896 * New native configurations
4898 NetBSD/amd64 x86_64-*-netbsd*
4899 OpenBSD/amd64 x86_64-*-openbsd*
4900 OpenBSD/alpha alpha*-*-openbsd*
4901 OpenBSD/sparc sparc-*-openbsd*
4902 OpenBSD/sparc64 sparc64-*-openbsd*
4904 * New debugging protocols
4906 M32R with SDI protocol m32r-*-elf*
4908 * "set prompt-escape-char" command deleted.
4910 The command "set prompt-escape-char" has been deleted. This command,
4911 and its very obscure effet on GDB's prompt, was never documented,
4912 tested, nor mentioned in the NEWS file.
4914 * OBSOLETE configurations and files
4916 Configurations that have been declared obsolete in this release have
4917 been commented out. Unless there is activity to revive these
4918 configurations, the next release of GDB will have their sources
4919 permanently REMOVED.
4921 Sun 3, running SunOS 3 m68*-*-sunos3*
4922 Sun 3, running SunOS 4 m68*-*-sunos4*
4923 Sun 2, running SunOS 3 m68000-*-sunos3*
4924 Sun 2, running SunOS 4 m68000-*-sunos4*
4925 Motorola 680x0 running LynxOS m68*-*-lynxos*
4926 AT&T 3b1/Unix pc m68*-att-*
4927 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4928 decstation mips-dec-* mips-little-*
4929 riscos mips-*-riscos* mips-*-sysv*
4930 sonymips mips-sony-*
4931 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4933 * REMOVED configurations and files
4935 SGI Irix-4.x mips-sgi-irix4 or iris4
4936 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4937 Z8000 simulator z8k-zilog-none or z8ksim
4938 Matsushita MN10200 w/simulator mn10200-*-*
4939 H8/500 simulator h8500-hitachi-hms or h8500hms
4940 HP/PA running BSD hppa*-*-bsd*
4941 HP/PA running OSF/1 hppa*-*-osf*
4942 HP/PA Pro target hppa*-*-pro*
4943 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4944 386BSD i[3456]86-*-bsd*
4945 Sequent family i[3456]86-sequent-sysv4*
4946 i[3456]86-sequent-sysv*
4947 i[3456]86-sequent-bsd*
4948 SPARC running LynxOS sparc-*-lynxos*
4949 SPARC running SunOS 4 sparc-*-sunos4*
4950 Tsqware Sparclet sparclet-*-*
4951 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4953 *** Changes in GDB 6.0:
4957 Support for debugging the Objective-C programming language has been
4958 integrated into GDB.
4960 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4962 DWARF 2's Call Frame Information makes available compiler generated
4963 information that more exactly describes the program's run-time stack.
4964 By using this information, GDB is able to provide more robust stack
4967 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4968 have been updated to use a new backtrace mechanism which includes
4969 DWARF 2 CFI support.
4973 GDB's remote protocol has been extended to include support for hosted
4974 file I/O (where the remote target uses GDB's file system). See GDB's
4975 remote protocol documentation for details.
4977 * All targets using the new architecture framework.
4979 All of GDB's targets have been updated to use the new internal
4980 architecture framework. The way is now open for future GDB releases
4981 to include cross-architecture native debugging support (i386 on amd64,
4984 * GNU/Linux's Thread Local Storage (TLS)
4986 GDB now includes support for for the GNU/Linux implementation of
4987 per-thread variables.
4989 * GNU/Linux's Native POSIX Thread Library (NPTL)
4991 GDB's thread code has been updated to work with either the new
4992 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4994 * Separate debug info.
4996 GDB, in conjunction with BINUTILS, now supports a mechanism for
4997 automatically loading debug information from a separate file. Instead
4998 of shipping full debug and non-debug versions of system libraries,
4999 system integrators can now instead ship just the stripped libraries
5000 and optional debug files.
5002 * DWARF 2 Location Expressions
5004 DWARF 2 Location Expressions allow the compiler to more completely
5005 describe the location of variables (even in optimized code) to the
5008 GDB now includes preliminary support for location expressions (support
5009 for DW_OP_piece is still missing).
5013 A number of long standing bugs that caused GDB to die while starting a
5014 Java application have been fixed. GDB's Java support is now
5015 considered "useable".
5017 * GNU/Linux support for fork, vfork, and exec.
5019 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5020 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5023 * GDB supports logging output to a file
5025 There are two new commands, "set logging" and "show logging", which can be
5026 used to capture GDB's output to a file.
5028 * The meaning of "detach" has changed for gdbserver
5030 The "detach" command will now resume the application, as documented. To
5031 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5034 * d10v, m68hc11 `regs' command deprecated
5036 The `info registers' command has been updated so that it displays the
5037 registers using a format identical to the old `regs' command.
5041 A new command, "maint set profile on/off", has been added. This command can
5042 be used to enable or disable profiling while running GDB, to profile a
5043 session or a set of commands. In addition there is a new configure switch,
5044 "--enable-profiling", which will cause GDB to be compiled with profiling
5045 data, for more informative profiling results.
5047 * Default MI syntax changed to "mi2".
5049 The default MI (machine interface) syntax, enabled by the command line
5050 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5051 "mi1", can be enabled by specifying the option "-i=mi1".
5053 Support for the original "mi0" syntax (included in GDB 5.0) has been
5056 Fix for gdb/192: removed extraneous space when displaying frame level.
5057 Fix for gdb/672: update changelist is now output in mi list format.
5058 Fix for gdb/702: a -var-assign that updates the value now shows up
5059 in a subsequent -var-update.
5061 * New native configurations.
5063 FreeBSD/amd64 x86_64-*-freebsd*
5065 * Multi-arched targets.
5067 HP/PA HPUX11 hppa*-*-hpux*
5068 Renesas M32R/D w/simulator m32r-*-elf*
5070 * OBSOLETE configurations and files
5072 Configurations that have been declared obsolete in this release have
5073 been commented out. Unless there is activity to revive these
5074 configurations, the next release of GDB will have their sources
5075 permanently REMOVED.
5077 Z8000 simulator z8k-zilog-none or z8ksim
5078 Matsushita MN10200 w/simulator mn10200-*-*
5079 H8/500 simulator h8500-hitachi-hms or h8500hms
5080 HP/PA running BSD hppa*-*-bsd*
5081 HP/PA running OSF/1 hppa*-*-osf*
5082 HP/PA Pro target hppa*-*-pro*
5083 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5084 Sequent family i[3456]86-sequent-sysv4*
5085 i[3456]86-sequent-sysv*
5086 i[3456]86-sequent-bsd*
5087 Tsqware Sparclet sparclet-*-*
5088 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5090 * REMOVED configurations and files
5093 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5094 IBM AIX PS/2 i[3456]86-*-aix
5095 i386 running Mach 3.0 i[3456]86-*-mach3*
5096 i386 running Mach i[3456]86-*-mach*
5097 i386 running OSF/1 i[3456]86-*osf1mk*
5098 HP/Apollo 68k Family m68*-apollo*-sysv*,
5100 m68*-hp-bsd*, m68*-hp-hpux*
5101 Argonaut Risc Chip (ARC) arc-*-*
5102 Mitsubishi D30V d30v-*-*
5103 Fujitsu FR30 fr30-*-elf*
5104 OS/9000 i[34]86-*-os9k
5105 I960 with MON960 i960-*-coff
5107 * MIPS $fp behavior changed
5109 The convenience variable $fp, for the MIPS, now consistently returns
5110 the address of the current frame's base. Previously, depending on the
5111 context, $fp could refer to either $sp or the current frame's base
5112 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5113 The GNU Source-Level Debugger''.
5115 *** Changes in GDB 5.3:
5117 * GNU/Linux shared library multi-threaded performance improved.
5119 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5120 `/proc', in preference to `ptrace' for memory reads. This may result
5121 in an improvement in the start-up time of multi-threaded, shared
5122 library applications when run under GDB. One GDB user writes: ``loads
5123 shared libs like mad''.
5125 * ``gdbserver'' now supports multi-threaded applications on some targets
5127 Support for debugging multi-threaded applications which use
5128 the GNU/Linux LinuxThreads package has been added for
5129 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5130 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5132 * GDB now supports C/C++ preprocessor macros.
5134 GDB now expands preprocessor macro invocations in C/C++ expressions,
5135 and provides various commands for showing macro definitions and how
5138 The new command `macro expand EXPRESSION' expands any macro
5139 invocations in expression, and shows the result.
5141 The new command `show macro MACRO-NAME' shows the definition of the
5142 macro named MACRO-NAME, and where it was defined.
5144 Most compilers don't include information about macros in the debugging
5145 information by default. In GCC 3.1, for example, you need to compile
5146 your program with the options `-gdwarf-2 -g3'. If the macro
5147 information is present in the executable, GDB will read it.
5149 * Multi-arched targets.
5151 DEC Alpha (partial) alpha*-*-*
5152 DEC VAX (partial) vax-*-*
5154 National Semiconductor NS32000 (partial) ns32k-*-*
5155 Motorola 68000 (partial) m68k-*-*
5156 Motorola MCORE mcore-*-*
5160 Fujitsu FRV architecture added by Red Hat frv*-*-*
5163 * New native configurations
5165 Alpha NetBSD alpha*-*-netbsd*
5166 SH NetBSD sh*-*-netbsdelf*
5167 MIPS NetBSD mips*-*-netbsd*
5168 UltraSPARC NetBSD sparc64-*-netbsd*
5170 * OBSOLETE configurations and files
5172 Configurations that have been declared obsolete in this release have
5173 been commented out. Unless there is activity to revive these
5174 configurations, the next release of GDB will have their sources
5175 permanently REMOVED.
5177 Mitsubishi D30V d30v-*-*
5178 OS/9000 i[34]86-*-os9k
5179 IBM AIX PS/2 i[3456]86-*-aix
5180 Fujitsu FR30 fr30-*-elf*
5181 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5182 Argonaut Risc Chip (ARC) arc-*-*
5183 i386 running Mach 3.0 i[3456]86-*-mach3*
5184 i386 running Mach i[3456]86-*-mach*
5185 i386 running OSF/1 i[3456]86-*osf1mk*
5186 HP/Apollo 68k Family m68*-apollo*-sysv*,
5188 m68*-hp-bsd*, m68*-hp-hpux*
5189 I960 with MON960 i960-*-coff
5191 * OBSOLETE languages
5193 CHILL, a Pascal like language used by telecommunications companies.
5195 * REMOVED configurations and files
5197 AMD 29k family via UDI a29k-amd-udi, udi29k
5198 A29K VxWorks a29k-*-vxworks
5199 AMD 29000 embedded, using EBMON a29k-none-none
5200 AMD 29000 embedded with COFF a29k-none-coff
5201 AMD 29000 embedded with a.out a29k-none-aout
5203 testsuite/gdb.hp/gdb.threads-hp/ directory
5205 * New command "set max-user-call-depth <nnn>"
5207 This command allows the user to limit the call depth of user-defined
5208 commands. The default is 1024.
5210 * Changes in FreeBSD/i386 native debugging.
5212 Support for the "generate-core-file" has been added.
5214 * New commands "dump", "append", and "restore".
5216 These commands allow data to be copied from target memory
5217 to a bfd-format or binary file (dump and append), and back
5218 from a file into memory (restore).
5220 * Improved "next/step" support on multi-processor Alpha Tru64.
5222 The previous single-step mechanism could cause unpredictable problems,
5223 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5224 of a software single-step mechanism prevents this.
5226 *** Changes in GDB 5.2.1:
5234 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5235 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5236 Fix, by Joel Brobecker imported from mainline.
5238 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5239 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5240 Fix, by Fred Fish, imported from mainline.
5242 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5243 Surprisingly enough, it works now.
5244 By Michal Ludvig, imported from mainline.
5246 i386 hardware watchpoint support:
5247 avoid misses on second run for some targets.
5248 By Pierre Muller, imported from mainline.
5250 *** Changes in GDB 5.2:
5252 * New command "set trust-readonly-sections on[off]".
5254 This command is a hint that tells gdb that read-only sections
5255 really are read-only (ie. that their contents will not change).
5256 In this mode, gdb will go to the object file rather than the
5257 target to read memory from read-only sections (such as ".text").
5258 This can be a significant performance improvement on some
5259 (notably embedded) targets.
5261 * New command "generate-core-file" (or "gcore").
5263 This new gdb command allows the user to drop a core file of the child
5264 process state at any time. So far it's been implemented only for
5265 GNU/Linux and Solaris, but should be relatively easily ported to other
5266 hosts. Argument is core file name (defaults to core.<pid>).
5268 * New command line option
5270 GDB now accepts --pid or -p followed by a process id.
5272 * Change in command line behavior -- corefiles vs. process ids.
5274 There is a subtle behavior in the way in which GDB handles
5275 command line arguments. The first non-flag argument is always
5276 a program to debug, but the second non-flag argument may either
5277 be a corefile or a process id. Previously, GDB would attempt to
5278 open the second argument as a corefile, and if that failed, would
5279 issue a superfluous error message and then attempt to attach it as
5280 a process. Now, if the second argument begins with a non-digit,
5281 it will be treated as a corefile. If it begins with a digit,
5282 GDB will attempt to attach it as a process, and if no such process
5283 is found, will then attempt to open it as a corefile.
5285 * Changes in ARM configurations.
5287 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5288 configuration is fully multi-arch.
5290 * New native configurations
5292 ARM NetBSD arm*-*-netbsd*
5293 x86 OpenBSD i[3456]86-*-openbsd*
5294 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5295 Sparc64 running FreeBSD sparc64-*-freebsd*
5299 Sanyo XStormy16 xstormy16-elf
5301 * OBSOLETE configurations and files
5303 Configurations that have been declared obsolete in this release have
5304 been commented out. Unless there is activity to revive these
5305 configurations, the next release of GDB will have their sources
5306 permanently REMOVED.
5308 AMD 29k family via UDI a29k-amd-udi, udi29k
5309 A29K VxWorks a29k-*-vxworks
5310 AMD 29000 embedded, using EBMON a29k-none-none
5311 AMD 29000 embedded with COFF a29k-none-coff
5312 AMD 29000 embedded with a.out a29k-none-aout
5314 testsuite/gdb.hp/gdb.threads-hp/ directory
5316 * REMOVED configurations and files
5318 TI TMS320C80 tic80-*-*
5320 PowerPC Solaris powerpcle-*-solaris*
5321 PowerPC Windows NT powerpcle-*-cygwin32
5322 PowerPC Netware powerpc-*-netware*
5323 Harris/CXUX m88k m88*-harris-cxux*
5324 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5325 ns32k-utek-sysv* ns32k-utek-*
5326 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5327 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5328 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5329 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5330 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5332 * Changes to command line processing
5334 The new `--args' feature can be used to specify command-line arguments
5335 for the inferior from gdb's command line.
5337 * Changes to key bindings
5339 There is a new `operate-and-get-next' function bound to `C-o'.
5341 *** Changes in GDB 5.1.1
5343 Fix compile problem on DJGPP.
5345 Fix a problem with floating-point registers on the i386 being
5348 Fix to stop GDB crashing on .debug_str debug info.
5350 Numerous documentation fixes.
5352 Numerous testsuite fixes.
5354 *** Changes in GDB 5.1:
5356 * New native configurations
5358 Alpha FreeBSD alpha*-*-freebsd*
5359 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5360 MIPS GNU/Linux mips*-*-linux*
5361 MIPS SGI Irix 6.x mips*-sgi-irix6*
5362 ia64 AIX ia64-*-aix*
5363 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5367 Motorola 68HC11 and 68HC12 m68hc11-elf
5369 UltraSparc running GNU/Linux sparc64-*-linux*
5371 * OBSOLETE configurations and files
5373 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5374 Harris/CXUX m88k m88*-harris-cxux*
5375 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5376 ns32k-utek-sysv* ns32k-utek-*
5377 TI TMS320C80 tic80-*-*
5379 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5380 PowerPC Solaris powerpcle-*-solaris*
5381 PowerPC Windows NT powerpcle-*-cygwin32
5382 PowerPC Netware powerpc-*-netware*
5383 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5384 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5385 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5386 Apple Macintosh (MPW) host N/A
5388 stuff.c (Program to stuff files into a specially prepared space in kdb)
5389 kdb-start.c (Main loop for the standalone kernel debugger)
5391 Configurations that have been declared obsolete in this release have
5392 been commented out. Unless there is activity to revive these
5393 configurations, the next release of GDB will have their sources
5394 permanently REMOVED.
5396 * REMOVED configurations and files
5398 Altos 3068 m68*-altos-*
5399 Convex c1-*-*, c2-*-*
5401 ARM RISCix arm-*-* (as host)
5405 * GDB has been converted to ISO C.
5407 GDB's source code has been converted to ISO C. In particular, the
5408 sources are fully protoized, and rely on standard headers being
5413 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5415 * The MI enabled by default.
5417 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5418 revised and enabled by default. Packages which use GDB as a debugging
5419 engine behind a UI or another front end are encouraged to switch to
5420 using the GDB/MI interface, instead of the old annotations interface
5421 which is now deprecated.
5423 * Support for debugging Pascal programs.
5425 GDB now includes support for debugging Pascal programs. The following
5426 main features are supported:
5428 - Pascal-specific data types such as sets;
5430 - automatic recognition of Pascal sources based on file-name
5433 - Pascal-style display of data types, variables, and functions;
5435 - a Pascal expression parser.
5437 However, some important features are not yet supported.
5439 - Pascal string operations are not supported at all;
5441 - there are some problems with boolean types;
5443 - Pascal type hexadecimal constants are not supported
5444 because they conflict with the internal variables format;
5446 - support for Pascal objects and classes is not full yet;
5448 - unlike Pascal, GDB is case-sensitive for symbol names.
5450 * Changes in completion.
5452 Commands such as `shell', `run' and `set args', which pass arguments
5453 to inferior programs, now complete on file names, similar to what
5454 users expect at the shell prompt.
5456 Commands which accept locations, such as `disassemble', `print',
5457 `breakpoint', `until', etc. now complete on filenames as well as
5458 program symbols. Thus, if you type "break foob TAB", and the source
5459 files linked into the programs include `foobar.c', that file name will
5460 be one of the candidates for completion. However, file names are not
5461 considered for completion after you typed a colon that delimits a file
5462 name from a name of a function in that file, as in "break foo.c:bar".
5464 `set demangle-style' completes on available demangling styles.
5466 * New platform-independent commands:
5468 It is now possible to define a post-hook for a command as well as a
5469 hook that runs before the command. For more details, see the
5470 documentation of `hookpost' in the GDB manual.
5472 * Changes in GNU/Linux native debugging.
5474 Support for debugging multi-threaded programs has been completely
5475 revised for all platforms except m68k and sparc. You can now debug as
5476 many threads as your system allows you to have.
5478 Attach/detach is supported for multi-threaded programs.
5480 Support for SSE registers was added for x86. This doesn't work for
5481 multi-threaded programs though.
5483 * Changes in MIPS configurations.
5485 Multi-arch support is enabled for all MIPS configurations.
5487 GDB can now be built as native debugger on SGI Irix 6.x systems for
5488 debugging n32 executables. (Debugging 64-bit executables is not yet
5491 * Unified support for hardware watchpoints in all x86 configurations.
5493 Most (if not all) native x86 configurations support hardware-assisted
5494 breakpoints and watchpoints in a unified manner. This support
5495 implements debug register sharing between watchpoints, which allows to
5496 put a virtually infinite number of watchpoints on the same address,
5497 and also supports watching regions up to 16 bytes with several debug
5500 The new maintenance command `maintenance show-debug-regs' toggles
5501 debugging print-outs in functions that insert, remove, and test
5502 watchpoints and hardware breakpoints.
5504 * Changes in the DJGPP native configuration.
5506 New command ``info dos sysinfo'' displays assorted information about
5507 the CPU, OS, memory, and DPMI server.
5509 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5510 display information about segment descriptors stored in GDT, LDT, and
5513 New commands ``info dos pde'' and ``info dos pte'' display entries
5514 from Page Directory and Page Tables (for now works with CWSDPMI only).
5515 New command ``info dos address-pte'' displays the Page Table entry for
5516 a given linear address.
5518 GDB can now pass command lines longer than 126 characters to the
5519 program being debugged (requires an update to the libdbg.a library
5520 which is part of the DJGPP development kit).
5522 DWARF2 debug info is now supported.
5524 It is now possible to `step' and `next' through calls to `longjmp'.
5526 * Changes in documentation.
5528 All GDB documentation was converted to GFDL, the GNU Free
5529 Documentation License.
5531 Tracepoints-related commands are now fully documented in the GDB
5534 TUI, the Text-mode User Interface, is now documented in the manual.
5536 Tracepoints-related commands are now fully documented in the GDB
5539 The "GDB Internals" manual now has an index. It also includes
5540 documentation of `ui_out' functions, GDB coding standards, x86
5541 hardware watchpoints, and memory region attributes.
5543 * GDB's version number moved to ``version.in''
5545 The Makefile variable VERSION has been replaced by the file
5546 ``version.in''. People creating GDB distributions should update the
5547 contents of this file.
5551 GUD support is now a standard part of the EMACS distribution.
5553 *** Changes in GDB 5.0:
5555 * Improved support for debugging FP programs on x86 targets
5557 Unified and much-improved support for debugging floating-point
5558 programs on all x86 targets. In particular, ``info float'' now
5559 displays the FP registers in the same format on all x86 targets, with
5560 greater level of detail.
5562 * Improvements and bugfixes in hardware-assisted watchpoints
5564 It is now possible to watch array elements, struct members, and
5565 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5566 on x86 targets no longer erroneously trigger when the address is
5569 * Improvements in the native DJGPP version of GDB
5571 The distribution now includes all the scripts and auxiliary files
5572 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5573 machines ``out of the box''.
5575 The DJGPP version can now debug programs that use signals. It is
5576 possible to catch signals that happened in the debuggee, deliver
5577 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5578 would kill the program being debugged.) Programs that hook hardware
5579 interrupts (keyboard, timer, etc.) can also be debugged.
5581 It is now possible to debug DJGPP programs that redirect their
5582 standard handles or switch them to raw (as opposed to cooked) mode, or
5583 even close them. The command ``run < foo > bar'' works as expected,
5584 and ``info terminal'' reports useful information about the debuggee's
5585 terminal, including raw/cooked mode, redirection, etc.
5587 The DJGPP version now uses termios functions for console I/O, which
5588 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5591 DOS-style file names with drive letters are now fully supported by
5594 It is now possible to debug DJGPP programs that switch their working
5595 directory. It is also possible to rerun the debuggee any number of
5596 times without restarting GDB; thus, you can use the same setup,
5597 breakpoints, etc. for many debugging sessions.
5599 * New native configurations
5601 ARM GNU/Linux arm*-*-linux*
5602 PowerPC GNU/Linux powerpc-*-linux*
5606 Motorola MCore mcore-*-*
5607 x86 VxWorks i[3456]86-*-vxworks*
5608 PowerPC VxWorks powerpc-*-vxworks*
5609 TI TMS320C80 tic80-*-*
5611 * OBSOLETE configurations
5613 Altos 3068 m68*-altos-*
5614 Convex c1-*-*, c2-*-*
5616 ARM RISCix arm-*-* (as host)
5619 Configurations that have been declared obsolete will be commented out,
5620 but the code will be left in place. If there is no activity to revive
5621 these configurations before the next release of GDB, the sources will
5622 be permanently REMOVED.
5624 * Gould support removed
5626 Support for the Gould PowerNode and NP1 has been removed.
5628 * New features for SVR4
5630 On SVR4 native platforms (such as Solaris), if you attach to a process
5631 without first loading a symbol file, GDB will now attempt to locate and
5632 load symbols from the running process's executable file.
5634 * Many C++ enhancements
5636 C++ support has been greatly improved. Overload resolution now works properly
5637 in almost all cases. RTTI support is on the way.
5639 * Remote targets can connect to a sub-program
5641 A popen(3) style serial-device has been added. This device starts a
5642 sub-process (such as a stand-alone simulator) and then communicates
5643 with that. The sub-program to run is specified using the syntax
5644 ``|<program> <args>'' vis:
5646 (gdb) set remotedebug 1
5647 (gdb) target extended-remote |mn10300-elf-sim program-args
5649 * MIPS 64 remote protocol
5651 A long standing bug in the mips64 remote protocol where by GDB
5652 expected certain 32 bit registers (ex SR) to be transfered as 32
5653 instead of 64 bits has been fixed.
5655 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5656 added to provide backward compatibility with older versions of GDB.
5658 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5660 The command ``set remotebinarydownload'' command has been replaced by
5661 ``set remote X-packet''. Other commands in ``set remote'' family
5662 include ``set remote P-packet''.
5664 * Breakpoint commands accept ranges.
5666 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5667 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5668 ``tracepoint passcount'' also accepts a range of tracepoints.
5670 * ``apropos'' command added.
5672 The ``apropos'' command searches through command names and
5673 documentation strings, printing out matches, making it much easier to
5674 try to find a command that does what you are looking for.
5678 A new machine oriented interface (MI) has been added to GDB. This
5679 interface is designed for debug environments running GDB as a separate
5680 process. This is part of the long term libGDB project. See the
5681 "GDB/MI" chapter of the GDB manual for further information. It can be
5682 enabled by configuring with:
5684 .../configure --enable-gdbmi
5686 *** Changes in GDB-4.18:
5688 * New native configurations
5690 HP-UX 10.20 hppa*-*-hpux10.20
5691 HP-UX 11.x hppa*-*-hpux11.0*
5692 M68K GNU/Linux m68*-*-linux*
5696 Fujitsu FR30 fr30-*-elf*
5697 Intel StrongARM strongarm-*-*
5698 Mitsubishi D30V d30v-*-*
5700 * OBSOLETE configurations
5702 Gould PowerNode, NP1 np1-*-*, pn-*-*
5704 Configurations that have been declared obsolete will be commented out,
5705 but the code will be left in place. If there is no activity to revive
5706 these configurations before the next release of GDB, the sources will
5707 be permanently REMOVED.
5711 As a compatibility experiment, GDB's source files buildsym.h and
5712 buildsym.c have been converted to pure standard C, no longer
5713 containing any K&R compatibility code. We believe that all systems in
5714 use today either come with a standard C compiler, or have a GCC port
5715 available. If this is not true, please report the affected
5716 configuration to bug-gdb@gnu.org immediately. See the README file for
5717 information about getting a standard C compiler if you don't have one
5722 GDB now uses readline 2.2.
5724 * set extension-language
5726 You can now control the mapping between filename extensions and source
5727 languages by using the `set extension-language' command. For instance,
5728 you can ask GDB to treat .c files as C++ by saying
5729 set extension-language .c c++
5730 The command `info extensions' lists all of the recognized extensions
5731 and their associated languages.
5733 * Setting processor type for PowerPC and RS/6000
5735 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5736 you can use the `set processor' command to specify what variant of the
5737 PowerPC family you are debugging. The command
5741 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5742 following PowerPC and RS6000 variants:
5744 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5745 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5747 403GC IBM PowerPC 403GC
5748 505 Motorola PowerPC 505
5749 860 Motorola PowerPC 860 or 850
5750 601 Motorola PowerPC 601
5751 602 Motorola PowerPC 602
5752 603 Motorola/IBM PowerPC 603 or 603e
5753 604 Motorola PowerPC 604 or 604e
5754 750 Motorola/IBM PowerPC 750 or 750
5756 At the moment, this command just tells GDB what to name the
5757 special-purpose processor registers. Since almost all the affected
5758 registers are inaccessible to user-level programs, this command is
5759 only useful for remote debugging in its present form.
5763 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5764 more extensive support for HP-UX. Added features include shared
5765 library support, kernel threads and hardware watchpoints for 11.00,
5766 support for HP's ANSI C and C++ compilers, and a compatibility mode
5767 for xdb and dbx commands.
5771 HP's donation includes the new concept of catchpoints, which is a
5772 generalization of the old catch command. On HP-UX, it is now possible
5773 to catch exec, fork, and vfork, as well as library loading.
5775 This means that the existing catch command has changed; its first
5776 argument now specifies the type of catch to be set up. See the
5777 output of "help catch" for a list of catchpoint types.
5779 * Debugging across forks
5781 On HP-UX, you can choose which process to debug when a fork() happens
5786 HP has donated a curses-based terminal user interface (TUI). To get
5787 it, build with --enable-tui. Although this can be enabled for any
5788 configuration, at present it only works for native HP debugging.
5790 * GDB remote protocol additions
5792 A new protocol packet 'X' that writes binary data is now available.
5793 Default behavior is to try 'X', then drop back to 'M' if the stub
5794 fails to respond. The settable variable `remotebinarydownload'
5795 allows explicit control over the use of 'X'.
5797 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5798 full 64-bit address. The command
5800 set remoteaddresssize 32
5802 can be used to revert to the old behaviour. For existing remote stubs
5803 the change should not be noticed, as the additional address information
5806 In order to assist in debugging stubs, you may use the maintenance
5807 command `packet' to send any text string to the stub. For instance,
5809 maint packet heythere
5811 sends the packet "$heythere#<checksum>". Note that it is very easy to
5812 disrupt a debugging session by sending the wrong packet at the wrong
5815 The compare-sections command allows you to compare section data on the
5816 target to what is in the executable file without uploading or
5817 downloading, by comparing CRC checksums.
5819 * Tracing can collect general expressions
5821 You may now collect general expressions at tracepoints. This requires
5822 further additions to the target-side stub; see tracepoint.c and
5823 doc/agentexpr.texi for further details.
5825 * mask-address variable for Mips
5827 For Mips targets, you may control the zeroing of the upper 32 bits of
5828 a 64-bit address by entering `set mask-address on'. This is mainly
5829 of interest to users of embedded R4xxx and R5xxx processors.
5831 * Higher serial baud rates
5833 GDB's serial code now allows you to specify baud rates 57600, 115200,
5834 230400, and 460800 baud. (Note that your host system may not be able
5835 to achieve all of these rates.)
5839 The i960 configuration now includes an initial implementation of a
5840 builtin simulator, contributed by Jim Wilson.
5843 *** Changes in GDB-4.17:
5845 * New native configurations
5847 Alpha GNU/Linux alpha*-*-linux*
5848 Unixware 2.x i[3456]86-unixware2*
5849 Irix 6.x mips*-sgi-irix6*
5850 PowerPC GNU/Linux powerpc-*-linux*
5851 PowerPC Solaris powerpcle-*-solaris*
5852 Sparc GNU/Linux sparc-*-linux*
5853 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5857 Argonaut Risc Chip (ARC) arc-*-*
5858 Hitachi H8/300S h8300*-*-*
5859 Matsushita MN10200 w/simulator mn10200-*-*
5860 Matsushita MN10300 w/simulator mn10300-*-*
5861 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5862 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5863 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5864 Mitsubishi D10V w/simulator d10v-*-*
5865 Mitsubishi M32R/D w/simulator m32r-*-elf*
5866 Tsqware Sparclet sparclet-*-*
5867 NEC V850 w/simulator v850-*-*
5869 * New debugging protocols
5871 ARM with RDI protocol arm*-*-*
5872 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5873 DDB and LSI variants of PMON protocol mips*-*-*
5874 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5875 PowerPC with SDS protocol powerpc{,le}-*-eabi
5876 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5880 All configurations can now understand and use the DWARF 2 debugging
5881 format. The choice is automatic, if the symbol file contains DWARF 2
5886 GDB now includes basic Java language support. This support is
5887 only useful with Java compilers that produce native machine code.
5889 * solib-absolute-prefix and solib-search-path
5891 For SunOS and SVR4 shared libraries, you may now set the prefix for
5892 loading absolute shared library symbol files, and the search path for
5893 locating non-absolute shared library symbol files.
5895 * Live range splitting
5897 GDB can now effectively debug code for which GCC has performed live
5898 range splitting as part of its optimization. See gdb/doc/LRS for
5899 more details on the expected format of the stabs information.
5903 GDB's support for the GNU Hurd, including thread debugging, has been
5904 updated to work with current versions of the Hurd.
5908 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5909 instruction set. ARM GDB automatically detects when Thumb
5910 instructions are in use, and adjusts disassembly and backtracing
5915 GDB's MIPS target configurations now handle the MIP16 16-bit
5920 GDB now includes support for overlays; if an executable has been
5921 linked such that multiple sections are based at the same address, GDB
5922 will decide which section to use for symbolic info. You can choose to
5923 control the decision manually, using overlay commands, or implement
5924 additional target-side support and use "overlay load-target" to bring
5925 in the overlay mapping. Do "help overlay" for more detail.
5929 The command "info symbol <address>" displays information about
5930 the symbol at the specified address.
5934 The standard remote protocol now includes an extension that allows
5935 asynchronous collection and display of trace data. This requires
5936 extensive support in the target-side debugging stub. Tracing mode
5937 includes a new interaction mode in GDB and new commands: see the
5938 file tracepoint.c for more details.
5942 Configurations for embedded MIPS now include a simulator contributed
5943 by Cygnus Solutions. The simulator supports the instruction sets
5944 of most MIPS variants.
5948 Sparc configurations may now include the ERC32 simulator contributed
5949 by the European Space Agency. The simulator is not built into
5950 Sparc targets by default; configure with --enable-sim to include it.
5954 For target configurations that may include multiple variants of a
5955 basic architecture (such as MIPS and SH), you may now set the
5956 architecture explicitly. "set arch" sets, "info arch" lists
5957 the possible architectures.
5959 *** Changes in GDB-4.16:
5961 * New native configurations
5963 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5964 M68K NetBSD m68k-*-netbsd*
5965 PowerPC AIX 4.x powerpc-*-aix*
5966 PowerPC MacOS powerpc-*-macos*
5967 PowerPC Windows NT powerpcle-*-cygwin32
5968 RS/6000 AIX 4.x rs6000-*-aix4*
5972 ARM with RDP protocol arm-*-*
5973 I960 with MON960 i960-*-coff
5974 MIPS VxWorks mips*-*-vxworks*
5975 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5976 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5978 Matra Sparclet sparclet-*-*
5982 The powerpc-eabi configuration now includes the PSIM simulator,
5983 contributed by Andrew Cagney, with assistance from Mike Meissner.
5984 PSIM is a very elaborate model of the PowerPC, including not only
5985 basic instruction set execution, but also details of execution unit
5986 performance and I/O hardware. See sim/ppc/README for more details.
5990 GDB now works with Solaris 2.5.
5992 * Windows 95/NT native
5994 GDB will now work as a native debugger on Windows 95 and Windows NT.
5995 To build it from source, you must use the "gnu-win32" environment,
5996 which uses a DLL to emulate enough of Unix to run the GNU tools.
5997 Further information, binaries, and sources are available at
5998 ftp.cygnus.com, under pub/gnu-win32.
6000 * dont-repeat command
6002 If a user-defined command includes the command `dont-repeat', then the
6003 command will not be repeated if the user just types return. This is
6004 useful if the command is time-consuming to run, so that accidental
6005 extra keystrokes don't run the same command many times.
6007 * Send break instead of ^C
6009 The standard remote protocol now includes an option to send a break
6010 rather than a ^C to the target in order to interrupt it. By default,
6011 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6013 * Remote protocol timeout
6015 The standard remote protocol includes a new variable `remotetimeout'
6016 that allows you to set the number of seconds before GDB gives up trying
6017 to read from the target. The default value is 2.
6019 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6021 By default GDB will automatically keep track of objects as they are
6022 loaded and unloaded by the dynamic linker. By using the command `set
6023 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6024 when shared library events occur, thus allowing you to set breakpoints
6025 in shared libraries which are explicitly loaded by the inferior.
6027 Note this feature does not work on hpux8. On hpux9 you must link
6028 /usr/lib/end.o into your program. This feature should work
6029 automatically on hpux10.
6031 * Irix 5.x hardware watchpoint support
6033 Irix 5 configurations now support the use of hardware watchpoints.
6035 * Mips protocol "SYN garbage limit"
6037 When debugging a Mips target using the `target mips' protocol, you
6038 may set the number of characters that GDB will ignore by setting
6039 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6040 every character. The default value is 1050.
6042 * Recording and replaying remote debug sessions
6044 If you set `remotelogfile' to the name of a file, gdb will write to it
6045 a recording of a remote debug session. This recording may then be
6046 replayed back to gdb using "gdbreplay". See gdbserver/README for
6047 details. This is useful when you have a problem with GDB while doing
6048 remote debugging; you can make a recording of the session and send it
6049 to someone else, who can then recreate the problem.
6051 * Speedups for remote debugging
6053 GDB includes speedups for downloading and stepping MIPS systems using
6054 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6055 and more efficient S-record downloading.
6057 * Memory use reductions and statistics collection
6059 GDB now uses less memory and reports statistics about memory usage.
6060 Try the `maint print statistics' command, for example.
6062 *** Changes in GDB-4.15:
6064 * Psymtabs for XCOFF
6066 The symbol reader for AIX GDB now uses partial symbol tables. This
6067 can greatly improve startup time, especially for large executables.
6069 * Remote targets use caching
6071 Remote targets now use a data cache to speed up communication with the
6072 remote side. The data cache could lead to incorrect results because
6073 it doesn't know about volatile variables, thus making it impossible to
6074 debug targets which use memory mapped I/O devices. `set remotecache
6075 off' turns the the data cache off.
6077 * Remote targets may have threads
6079 The standard remote protocol now includes support for multiple threads
6080 in the target system, using new protocol commands 'H' and 'T'. See
6081 gdb/remote.c for details.
6085 If GDB is configured with `--enable-netrom', then it will include
6086 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6087 acts as though it is a bank of ROM on the target board, but you can
6088 write into it over the network. GDB's support consists only of
6089 support for fast loading into the emulated ROM; to debug, you must use
6090 another protocol, such as standard remote protocol. The usual
6091 sequence is something like
6093 target nrom <netrom-hostname>
6095 target remote <netrom-hostname>:1235
6099 GDB now includes support for the Apple Macintosh, as a host only. It
6100 may be run as either an MPW tool or as a standalone application, and
6101 it can debug through the serial port. All the usual GDB commands are
6102 available, but to the target command, you must supply "serial" as the
6103 device type instead of "/dev/ttyXX". See mpw-README in the main
6104 directory for more information on how to build. The MPW configuration
6105 scripts */mpw-config.in support only a few targets, and only the
6106 mips-idt-ecoff target has been tested.
6110 GDB configuration now uses autoconf. This is not user-visible,
6111 but does simplify configuration and building.
6115 GDB now supports hpux10.
6117 *** Changes in GDB-4.14:
6119 * New native configurations
6121 x86 FreeBSD i[345]86-*-freebsd
6122 x86 NetBSD i[345]86-*-netbsd
6123 NS32k NetBSD ns32k-*-netbsd
6124 Sparc NetBSD sparc-*-netbsd
6128 A29K VxWorks a29k-*-vxworks
6129 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6130 CPU32 EST-300 emulator m68*-*-est*
6131 PowerPC ELF powerpc-*-elf
6134 * Alpha OSF/1 support for procfs
6136 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6137 possible to attach to running processes. As the mounting of the /proc
6138 filesystem is optional on the Alpha, GDB automatically determines
6139 the availability of /proc during startup. This can lead to problems
6140 if /proc is unmounted after GDB has been started.
6142 * Arguments to user-defined commands
6144 User commands may accept up to 10 arguments separated by whitespace.
6145 Arguments are accessed within the user command via $arg0..$arg9. A
6148 print $arg0 + $arg1 + $arg2
6150 To execute the command use:
6153 Defines the command "adder" which prints the sum of its three arguments.
6154 Note the arguments are text substitutions, so they may reference variables,
6155 use complex expressions, or even perform inferior function calls.
6157 * New `if' and `while' commands
6159 This makes it possible to write more sophisticated user-defined
6160 commands. Both commands take a single argument, which is the
6161 expression to evaluate, and must be followed by the commands to
6162 execute, one per line, if the expression is nonzero, the list being
6163 terminated by the word `end'. The `if' command list may include an
6164 `else' word, which causes the following commands to be executed only
6165 if the expression is zero.
6167 * Fortran source language mode
6169 GDB now includes partial support for Fortran 77. It will recognize
6170 Fortran programs and can evaluate a subset of Fortran expressions, but
6171 variables and functions may not be handled correctly. GDB will work
6172 with G77, but does not yet know much about symbols emitted by other
6175 * Better HPUX support
6177 Most debugging facilities now work on dynamic executables for HPPAs
6178 running hpux9 or later. You can attach to running dynamically linked
6179 processes, but by default the dynamic libraries will be read-only, so
6180 for instance you won't be able to put breakpoints in them. To change
6181 that behavior do the following before running the program:
6187 This will cause the libraries to be mapped private and read-write.
6188 To revert to the normal behavior, do this:
6194 You cannot set breakpoints or examine data in the library until after
6195 the library is loaded if the function/data symbols do not have
6198 GDB can now also read debug symbols produced by the HP C compiler on
6199 HPPAs (sorry, no C++, Fortran or 68k support).
6201 * Target byte order now dynamically selectable
6203 You can choose which byte order to use with a target system, via the
6204 commands "set endian big" and "set endian little", and you can see the
6205 current setting by using "show endian". You can also give the command
6206 "set endian auto", in which case GDB will use the byte order
6207 associated with the executable. Currently, only embedded MIPS
6208 configurations support dynamic selection of target byte order.
6210 * New DOS host serial code
6212 This version uses DPMI interrupts to handle buffered I/O, so you
6213 no longer need to run asynctsr when debugging boards connected to
6216 *** Changes in GDB-4.13:
6218 * New "complete" command
6220 This lists all the possible completions for the rest of the line, if it
6221 were to be given as a command itself. This is intended for use by emacs.
6223 * Trailing space optional in prompt
6225 "set prompt" no longer adds a space for you after the prompt you set. This
6226 allows you to set a prompt which ends in a space or one that does not.
6228 * Breakpoint hit counts
6230 "info break" now displays a count of the number of times the breakpoint
6231 has been hit. This is especially useful in conjunction with "ignore"; you
6232 can ignore a large number of breakpoint hits, look at the breakpoint info
6233 to see how many times the breakpoint was hit, then run again, ignoring one
6234 less than that number, and this will get you quickly to the last hit of
6237 * Ability to stop printing at NULL character
6239 "set print null-stop" will cause GDB to stop printing the characters of
6240 an array when the first NULL is encountered. This is useful when large
6241 arrays actually contain only short strings.
6243 * Shared library breakpoints
6245 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6246 breakpoints in shared libraries before the executable is run.
6248 * Hardware watchpoints
6250 There is a new hardware breakpoint for the watch command for sparclite
6251 targets. See gdb/sparclite/hw_breakpoint.note.
6253 Hardware watchpoints are also now supported under GNU/Linux.
6257 Annotations have been added. These are for use with graphical interfaces,
6258 and are still experimental. Currently only gdba.el uses these.
6260 * Improved Irix 5 support
6262 GDB now works properly with Irix 5.2.
6264 * Improved HPPA support
6266 GDB now works properly with the latest GCC and GAS.
6268 * New native configurations
6270 Sequent PTX4 i[34]86-sequent-ptx4
6271 HPPA running OSF/1 hppa*-*-osf*
6272 Atari TT running SVR4 m68*-*-sysv4*
6273 RS/6000 LynxOS rs6000-*-lynxos*
6277 OS/9000 i[34]86-*-os9k
6278 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6281 * Hitachi SH7000 and E7000-PC ICE support
6283 There is now support for communicating with the Hitachi E7000-PC ICE.
6284 This is available automatically when GDB is configured for the SH.
6288 As usual, a variety of small fixes and improvements, both generic
6289 and configuration-specific. See the ChangeLog for more detail.
6291 *** Changes in GDB-4.12:
6293 * Irix 5 is now supported
6297 GDB-4.12 on the HPPA has a number of changes which make it unable
6298 to debug the output from the currently released versions of GCC and
6299 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6300 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6301 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6304 *** Changes in GDB-4.11:
6306 * User visible changes:
6310 The "set remotedebug" option is now consistent between the mips remote
6311 target, remote targets using the gdb-specific protocol, UDI (AMD's
6312 debug protocol for the 29k) and the 88k bug monitor. It is now an
6313 integer specifying a debug level (normally 0 or 1, but 2 means more
6314 debugging info for the mips target).
6316 * DEC Alpha native support
6318 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6319 debug info, but GDB works fairly well with the DEC compiler and should
6320 work with a future GCC release. See the README file for a few
6321 Alpha-specific notes.
6323 * Preliminary thread implementation
6325 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6327 * LynxOS native and target support for 386
6329 This release has been hosted on LynxOS 2.2, and also can be configured
6330 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6333 * Improvements in C++ mangling/demangling.
6335 This release has much better g++ debugging, specifically in name
6336 mangling/demangling, virtual function calls, print virtual table,
6337 call methods, ...etc.
6339 *** Changes in GDB-4.10:
6341 * User visible changes:
6343 Remote debugging using the GDB-specific (`target remote') protocol now
6344 supports the `load' command. This is only useful if you have some
6345 other way of getting the stub to the target system, and you can put it
6346 somewhere in memory where it won't get clobbered by the download.
6348 Filename completion now works.
6350 When run under emacs mode, the "info line" command now causes the
6351 arrow to point to the line specified. Also, "info line" prints
6352 addresses in symbolic form (as well as hex).
6354 All vxworks based targets now support a user settable option, called
6355 vxworks-timeout. This option represents the number of seconds gdb
6356 should wait for responses to rpc's. You might want to use this if
6357 your vxworks target is, perhaps, a slow software simulator or happens
6358 to be on the far side of a thin network line.
6362 This release contains support for using a DEC alpha as a GDB host for
6363 cross debugging. Native alpha debugging is not supported yet.
6366 *** Changes in GDB-4.9:
6370 This is the first GDB release which is accompanied by a matching testsuite.
6371 The testsuite requires installation of dejagnu, which should be available
6372 via ftp from most sites that carry GNU software.
6376 'Cfront' style demangling has had its name changed to 'ARM' style, to
6377 emphasize that it was written from the specifications in the C++ Annotated
6378 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6379 disclaimers, it still generated too much confusion with users attempting to
6380 use gdb with AT&T cfront.
6384 GDB now uses a standard remote interface to a simulator library.
6385 So far, the library contains simulators for the Zilog Z8001/2, the
6386 Hitachi H8/300, H8/500 and Super-H.
6388 * New targets supported
6390 H8/300 simulator h8300-hitachi-hms or h8300hms
6391 H8/500 simulator h8500-hitachi-hms or h8500hms
6392 SH simulator sh-hitachi-hms or sh
6393 Z8000 simulator z8k-zilog-none or z8ksim
6394 IDT MIPS board over serial line mips-idt-ecoff
6396 Cross-debugging to GO32 targets is supported. It requires a custom
6397 version of the i386-stub.c module which is integrated with the
6398 GO32 memory extender.
6400 * New remote protocols
6402 MIPS remote debugging protocol.
6404 * New source languages supported
6406 This version includes preliminary support for Chill, a Pascal like language
6407 used by telecommunications companies. Chill support is also being integrated
6408 into the GNU compiler, but we don't know when it will be publically available.
6411 *** Changes in GDB-4.8:
6413 * HP Precision Architecture supported
6415 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6416 version of this support was available as a set of patches from the
6417 University of Utah. GDB does not support debugging of programs
6418 compiled with the HP compiler, because HP will not document their file
6419 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6420 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6422 Many problems in the preliminary version have been fixed.
6424 * Faster and better demangling
6426 We have improved template demangling and fixed numerous bugs in the GNU style
6427 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6428 character types (wchar_t) are now supported. Demangling of each symbol is now
6429 only done once, and is cached when the symbol table for a file is read in.
6430 This results in a small increase in memory usage for C programs, a moderate
6431 increase in memory usage for C++ programs, and a fantastic speedup in
6434 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6435 from the specifications in the Annotated Reference Manual, which AT&T's
6436 compiler does not actually implement.
6438 * G++ multiple inheritance compiler problem
6440 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6441 inheritance lattices was reworked to properly discover ambiguities. We
6442 recently found an example which causes this new algorithm to fail in a
6443 very subtle way, producing bad debug information for those classes.
6444 The file 'gcc.patch' (in this directory) can be applied to gcc to
6445 circumvent the problem. A future GCC release will contain a complete
6448 The previous G++ debug info problem (mentioned below for the gdb-4.7
6449 release) is fixed in gcc version 2.3.2.
6451 * Improved configure script
6453 The `configure' script will now attempt to guess your system type if
6454 you don't supply a host system type. The old scheme of supplying a
6455 host system triplet is preferable over using this. All the magic is
6456 done in the new `config.guess' script. Examine it for details.
6458 We have also brought our configure script much more in line with the FSF's
6459 version. It now supports the --with-xxx options. In particular,
6460 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6461 The resulting GDB will not be able to read arbitrary object file formats --
6462 only the format ``expected'' to be used on the configured target system.
6463 We hope to make this the default in a future release.
6465 * Documentation improvements
6467 There's new internal documentation on how to modify GDB, and how to
6468 produce clean changes to the code. We implore people to read it
6469 before submitting changes.
6471 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6472 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6473 `info' files are also provided. To build `info' files from scratch,
6474 you will need the latest `makeinfo' release, which will be available in
6475 a future texinfo-X.Y release.
6477 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6478 We're not sure exactly which versions have this problem, but it has
6479 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6480 or better. If that isn't possible, there is a patch in
6481 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6482 around this problem.
6486 GDB now supports array constants that can be used in expressions typed in by
6487 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6488 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6491 The new directory `gdb/sparclite' contains a program that demonstrates
6492 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6494 * New native hosts supported
6496 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6497 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6499 * New targets supported
6501 AMD 29k family via UDI a29k-amd-udi or udi29k
6503 * New file formats supported
6505 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6506 HPUX core files, and SCO 3.2v2 core files.
6510 Attaching to processes now works again; thanks for the many bug reports.
6512 We have also stomped on a bunch of core dumps caused by
6513 printf_filtered("%s") problems.
6515 We eliminated a copyright problem on the rpc and ptrace header files
6516 for VxWorks, which was discovered at the last minute during the 4.7
6517 release. You should now be able to build a VxWorks GDB.
6519 You can now interrupt gdb while an attached process is running. This
6520 will cause the attached process to stop, and give control back to GDB.
6522 We fixed problems caused by using too many file descriptors
6523 for reading symbols from object files and libraries. This was
6524 especially a problem for programs that used many (~100) shared
6527 The `step' command now only enters a subroutine if there is line number
6528 information for the subroutine. Otherwise it acts like the `next'
6529 command. Previously, `step' would enter subroutines if there was
6530 any debugging information about the routine. This avoids problems
6531 when using `cc -g1' on MIPS machines.
6533 * Internal improvements
6535 GDB's internal interfaces have been improved to make it easier to support
6536 debugging of multiple languages in the future.
6538 GDB now uses a common structure for symbol information internally.
6539 Minimal symbols (derived from linkage symbols in object files), partial
6540 symbols (from a quick scan of debug information), and full symbols
6541 contain a common subset of information, making it easier to write
6542 shared code that handles any of them.
6544 * New command line options
6546 We now accept --silent as an alias for --quiet.
6550 The memory-mapped-malloc library is now licensed under the GNU Library
6551 General Public License.
6553 *** Changes in GDB-4.7:
6555 * Host/native/target split
6557 GDB has had some major internal surgery to untangle the support for
6558 hosts and remote targets. Now, when you configure GDB for a remote
6559 target, it will no longer load in all of the support for debugging
6560 local programs on the host. When fully completed and tested, this will
6561 ensure that arbitrary host/target combinations are possible.
6563 The primary conceptual shift is to separate the non-portable code in
6564 GDB into three categories. Host specific code is required any time GDB
6565 is compiled on that host, regardless of the target. Target specific
6566 code relates to the peculiarities of the target, but can be compiled on
6567 any host. Native specific code is everything else: it can only be
6568 built when the host and target are the same system. Child process
6569 handling and core file support are two common `native' examples.
6571 GDB's use of /proc for controlling Unix child processes is now cleaner.
6572 It has been split out into a single module under the `target_ops' vector,
6573 plus two native-dependent functions for each system that uses /proc.
6575 * New hosts supported
6577 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6578 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6579 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6581 * New targets supported
6583 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6584 68030 and CPU32 m68030-*-*, m68332-*-*
6586 * New native hosts supported
6588 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6589 (386bsd is not well tested yet)
6590 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6592 * New file formats supported
6594 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6595 supports reading of `a.out.adobe' object files, which are an a.out
6596 format extended with minimal information about multiple sections.
6600 `show copying' is the same as the old `info copying'.
6601 `show warranty' is the same as `info warrantee'.
6602 These were renamed for consistency. The old commands continue to work.
6604 `info handle' is a new alias for `info signals'.
6606 You can now define pre-command hooks, which attach arbitrary command
6607 scripts to any command. The commands in the hook will be executed
6608 prior to the user's command. You can also create a hook which will be
6609 executed whenever the program stops. See gdb.texinfo.
6613 We now deal with Cfront style name mangling, and can even extract type
6614 info from mangled symbols. GDB can automatically figure out which
6615 symbol mangling style your C++ compiler uses.
6617 Calling of methods and virtual functions has been improved as well.
6621 The crash that occured when debugging Sun Ansi-C compiled binaries is
6622 fixed. This was due to mishandling of the extra N_SO stabs output
6625 We also finally got Ultrix 4.2 running in house, and fixed core file
6626 support, with help from a dozen people on the net.
6628 John M. Farrell discovered that the reason that single-stepping was so
6629 slow on all of the Mips based platforms (primarily SGI and DEC) was
6630 that we were trying to demangle and lookup a symbol used for internal
6631 purposes on every instruction that was being stepped through. Changing
6632 the name of that symbol so that it couldn't be mistaken for a C++
6633 mangled symbol sped things up a great deal.
6635 Rich Pixley sped up symbol lookups in general by getting much smarter
6636 about when C++ symbol mangling is necessary. This should make symbol
6637 completion (TAB on the command line) much faster. It's not as fast as
6638 we'd like, but it's significantly faster than gdb-4.6.
6642 A new user controllable variable 'call_scratch_address' can
6643 specify the location of a scratch area to be used when GDB
6644 calls a function in the target. This is necessary because the
6645 usual method of putting the scratch area on the stack does not work
6646 in systems that have separate instruction and data spaces.
6648 We integrated changes to support the 29k UDI (Universal Debugger
6649 Interface), but discovered at the last minute that we didn't have all
6650 of the appropriate copyright paperwork. We are working with AMD to
6651 resolve this, and hope to have it available soon.
6655 We have sped up the remote serial line protocol, especially for targets
6656 with lots of registers. It now supports a new `expedited status' ('T')
6657 message which can be used in place of the existing 'S' status message.
6658 This allows the remote stub to send only the registers that GDB
6659 needs to make a quick decision about single-stepping or conditional
6660 breakpoints, eliminating the need to fetch the entire register set for
6661 each instruction being stepped through.
6663 The GDB remote serial protocol now implements a write-through cache for
6664 registers, only re-reading the registers if the target has run.
6666 There is also a new remote serial stub for SPARC processors. You can
6667 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6668 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6669 processor with a serial port.
6673 Configure.in files have become much easier to read and modify. A new
6674 `table driven' format makes it more obvious what configurations are
6675 supported, and what files each one uses.
6679 There is a new opcodes library which will eventually contain all of the
6680 disassembly routines and opcode tables. At present, it only contains
6681 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6682 disassembler (binutils/objdump) to share these routines.
6684 The libiberty library is now copylefted under the GNU Library General
6685 Public License. This allows more liberal use, and was done so libg++
6686 can use it. This makes no difference to GDB, since the Library License
6687 grants all the rights from the General Public License.
6691 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6692 reference to the stabs symbol info used by the debugger. It is (as far
6693 as we know) the only published document on this fascinating topic. We
6694 encourage you to read it, compare it to the stabs information on your
6695 system, and send improvements on the document in general (to
6696 bug-gdb@prep.ai.mit.edu).
6698 And, of course, many bugs have been fixed.
6701 *** Changes in GDB-4.6:
6703 * Better support for C++ function names
6705 GDB now accepts as input the "demangled form" of C++ overloaded function
6706 names and member function names, and can do command completion on such names
6707 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6708 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6709 Make use of command completion, it is your friend.
6711 GDB also now accepts a variety of C++ mangled symbol formats. They are
6712 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6713 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6714 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6715 for the list of formats.
6717 * G++ symbol mangling problem
6719 Recent versions of gcc have a bug in how they emit debugging information for
6720 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6721 directory) can be applied to gcc to fix the problem. Alternatively, if you
6722 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6723 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6724 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6727 * New 'maintenance' command
6729 All of the commands related to hacking GDB internals have been moved out of
6730 the main command set, and now live behind the 'maintenance' command. This
6731 can also be abbreviated as 'mt'. The following changes were made:
6733 dump-me -> maintenance dump-me
6734 info all-breakpoints -> maintenance info breakpoints
6735 printmsyms -> maintenance print msyms
6736 printobjfiles -> maintenance print objfiles
6737 printpsyms -> maintenance print psymbols
6738 printsyms -> maintenance print symbols
6740 The following commands are new:
6742 maintenance demangle Call internal GDB demangler routine to
6743 demangle a C++ link name and prints the result.
6744 maintenance print type Print a type chain for a given symbol
6746 * Change to .gdbinit file processing
6748 We now read the $HOME/.gdbinit file before processing the argv arguments
6749 (e.g. reading symbol files or core files). This allows global parameters to
6750 be set, which will apply during the symbol reading. The ./.gdbinit is still
6751 read after argv processing.
6753 * New hosts supported
6755 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6757 GNU/Linux support i386-unknown-linux or linux
6759 We are also including code to support the HP/PA running BSD and HPUX. This
6760 is almost guaranteed not to work, as we didn't have time to test or build it
6761 for this release. We are including it so that the more adventurous (or
6762 masochistic) of you can play with it. We also had major problems with the
6763 fact that the compiler that we got from HP doesn't support the -g option.
6766 * New targets supported
6768 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6770 * More smarts about finding #include files
6772 GDB now remembers the compilation directory for all include files, and for
6773 all files from which C is generated (like yacc and lex sources). This
6774 greatly improves GDB's ability to find yacc/lex sources, and include files,
6775 especially if you are debugging your program from a directory different from
6776 the one that contains your sources.
6778 We also fixed a bug which caused difficulty with listing and setting
6779 breakpoints in include files which contain C code. (In the past, you had to
6780 try twice in order to list an include file that you hadn't looked at before.)
6782 * Interesting infernals change
6784 GDB now deals with arbitrary numbers of sections, where the symbols for each
6785 section must be relocated relative to that section's landing place in the
6786 target's address space. This work was needed to support ELF with embedded
6787 stabs used by Solaris-2.0.
6789 * Bug fixes (of course!)
6791 There have been loads of fixes for the following things:
6792 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6793 i960, stabs, DOS(GO32), procfs, etc...
6795 See the ChangeLog for details.
6797 *** Changes in GDB-4.5:
6799 * New machines supported (host and target)
6801 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6803 SGI Irix-4.x mips-sgi-irix4 or iris4
6805 * New malloc package
6807 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6808 Mmalloc is capable of handling mutiple heaps of memory. It is also
6809 capable of saving a heap to a file, and then mapping it back in later.
6810 This can be used to greatly speedup the startup of GDB by using a
6811 pre-parsed symbol table which lives in a mmalloc managed heap. For
6812 more details, please read mmalloc/mmalloc.texi.
6816 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6817 'help info proc' for details.
6819 * MIPS ecoff symbol table format
6821 The code that reads MIPS symbol table format is now supported on all hosts.
6822 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6825 * File name changes for MS-DOS
6827 Many files in the config directories have been renamed to make it easier to
6828 support GDB on MS-DOSe systems (which have very restrictive file name
6829 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6830 environment) is close to working but has some remaining problems. Note
6831 that debugging of DOS programs is not supported, due to limitations
6832 in the ``operating system'', but it can be used to host cross-debugging.
6834 * Cross byte order fixes
6836 Many fixes have been made to support cross debugging of Sparc and MIPS
6837 targets from hosts whose byte order differs.
6839 * New -mapped and -readnow options
6841 If memory-mapped files are available on your system through the 'mmap'
6842 system call, you can use the -mapped option on the `file' or
6843 `symbol-file' commands to cause GDB to write the symbols from your
6844 program into a reusable file. If the program you are debugging is
6845 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6846 Future GDB debugging sessions will notice the presence of this file,
6847 and will quickly map in symbol information from it, rather than reading
6848 the symbol table from the executable program. Using the '-mapped'
6849 option in a GDB `file' or `symbol-file' command has the same effect as
6850 starting GDB with the '-mapped' command-line option.
6852 You can cause GDB to read the entire symbol table immediately by using
6853 the '-readnow' option with any of the commands that load symbol table
6854 information (or on the GDB command line). This makes the command
6855 slower, but makes future operations faster.
6857 The -mapped and -readnow options are typically combined in order to
6858 build a `fred.syms' file that contains complete symbol information.
6859 A simple GDB invocation to do nothing but build a `.syms' file for future
6862 gdb -batch -nx -mapped -readnow programname
6864 The `.syms' file is specific to the host machine on which GDB is run.
6865 It holds an exact image of GDB's internal symbol table. It cannot be
6866 shared across multiple host platforms.
6868 * longjmp() handling
6870 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6871 siglongjmp() without losing control. This feature has not yet been ported to
6872 all systems. It currently works on many 386 platforms, all MIPS-based
6873 platforms (SGI, DECstation, etc), and Sun3/4.
6877 Preliminary work has been put in to support the new Solaris OS from Sun. At
6878 this time, it can control and debug processes, but it is not capable of
6883 As always, many many bug fixes. The major areas were with g++, and mipsread.
6884 People using the MIPS-based platforms should experience fewer mysterious
6885 crashes and trashed symbol tables.
6887 *** Changes in GDB-4.4:
6889 * New machines supported (host and target)
6891 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6893 BSD Reno on Vax vax-dec-bsd
6894 Ultrix on Vax vax-dec-ultrix
6896 * New machines supported (target)
6898 AMD 29000 embedded, using EBMON a29k-none-none
6902 GDB continues to improve its handling of C++. `References' work better.
6903 The demangler has also been improved, and now deals with symbols mangled as
6904 per the Annotated C++ Reference Guide.
6906 GDB also now handles `stabs' symbol information embedded in MIPS
6907 `ecoff' symbol tables. Since the ecoff format was not easily
6908 extensible to handle new languages such as C++, this appeared to be a
6909 good way to put C++ debugging info into MIPS binaries. This option
6910 will be supported in the GNU C compiler, version 2, when it is
6913 * New features for SVR4
6915 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6916 shared libraries. Debugging dynamically linked programs should present
6917 only minor differences from debugging statically linked programs.
6919 The `info proc' command will print out information about any process
6920 on an SVR4 system (including the one you are debugging). At the moment,
6921 it prints the address mappings of the process.
6923 If you bring up GDB on another SVR4 system, please send mail to
6924 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6926 * Better dynamic linking support in SunOS
6928 Reading symbols from shared libraries which contain debugging symbols
6929 now works properly. However, there remain issues such as automatic
6930 skipping of `transfer vector' code during function calls, which
6931 make it harder to debug code in a shared library, than to debug the
6932 same code linked statically.
6936 GDB is now using the latest `getopt' routines from the FSF. This
6937 version accepts the -- prefix for options with long names. GDB will
6938 continue to accept the old forms (-option and +option) as well.
6939 Various single letter abbreviations for options have been explicity
6940 added to the option table so that they won't get overshadowed in the
6941 future by other options that begin with the same letter.
6945 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6946 Many assorted bugs have been handled. Many more remain to be handled.
6947 See the various ChangeLog files (primarily in gdb and bfd) for details.
6950 *** Changes in GDB-4.3:
6952 * New machines supported (host and target)
6954 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6955 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6956 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6958 * Almost SCO Unix support
6960 We had hoped to support:
6961 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6962 (except for core file support), but we discovered very late in the release
6963 that it has problems with process groups that render gdb unusable. Sorry
6964 about that. I encourage people to fix it and post the fixes.
6966 * Preliminary ELF and DWARF support
6968 GDB can read ELF object files on System V Release 4, and can handle
6969 debugging records for C, in DWARF format, in ELF files. This support
6970 is preliminary. If you bring up GDB on another SVR4 system, please
6971 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6976 GDB now uses the latest `readline' library. One user-visible change
6977 is that two tabs will list possible command completions, which previously
6978 required typing M-? (meta-question mark, or ESC ?).
6982 The `stepi' bug that many of you noticed has been squashed.
6983 Many bugs in C++ have been handled. Many more remain to be handled.
6984 See the various ChangeLog files (primarily in gdb and bfd) for details.
6986 * State of the MIPS world (in case you wondered):
6988 GDB can understand the symbol tables emitted by the compilers
6989 supplied by most vendors of MIPS-based machines, including DEC. These
6990 symbol tables are in a format that essentially nobody else uses.
6992 Some versions of gcc come with an assembler post-processor called
6993 mips-tfile. This program is required if you want to do source-level
6994 debugging of gcc-compiled programs. I believe FSF does not ship
6995 mips-tfile with gcc version 1, but it will eventually come with gcc
6998 Debugging of g++ output remains a problem. g++ version 1.xx does not
6999 really support it at all. (If you're lucky, you should be able to get
7000 line numbers and stack traces to work, but no parameters or local
7001 variables.) With some work it should be possible to improve the
7004 When gcc version 2 is released, you will have somewhat better luck.
7005 However, even then you will get confusing results for inheritance and
7008 We will eventually provide full debugging of g++ output on
7009 DECstations. This will probably involve some kind of stabs-in-ecoff
7010 encapulation, but the details have not been worked out yet.
7013 *** Changes in GDB-4.2:
7015 * Improved configuration
7017 Only one copy of `configure' exists now, and it is not self-modifying.
7018 Porting BFD is simpler.
7022 The `step' and `next' commands now only stop at the first instruction
7023 of a source line. This prevents the multiple stops that used to occur
7024 in switch statements, for-loops, etc. `Step' continues to stop if a
7025 function that has debugging information is called within the line.
7029 Lots of small bugs fixed. More remain.
7031 * New host supported (not target)
7033 Intel 386 PC clone running Mach i386-none-mach
7036 *** Changes in GDB-4.1:
7038 * Multiple source language support
7040 GDB now has internal scaffolding to handle several source languages.
7041 It determines the type of each source file from its filename extension,
7042 and will switch expression parsing and number formatting to match the
7043 language of the function in the currently selected stack frame.
7044 You can also specifically set the language to be used, with
7045 `set language c' or `set language modula-2'.
7049 GDB now has preliminary support for the GNU Modula-2 compiler,
7050 currently under development at the State University of New York at
7051 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7052 continue through the fall of 1991 and into 1992.
7054 Other Modula-2 compilers are currently not supported, and attempting to
7055 debug programs compiled with them will likely result in an error as the
7056 symbol table is read. Feel free to work on it, though!
7058 There are hooks in GDB for strict type checking and range checking,
7059 in the `Modula-2 philosophy', but they do not currently work.
7063 GDB can now write to executable and core files (e.g. patch
7064 a variable's value). You must turn this switch on, specify
7065 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7066 by assigning a new value to a variable. Modifications take
7069 * Automatic SunOS shared library reading
7071 When you run your program, GDB automatically determines where its
7072 shared libraries (if any) have been loaded, and reads their symbols.
7073 The `share' command is no longer needed. This also works when
7074 examining core files.
7078 You can specify the number of lines that the `list' command shows.
7081 * New machines supported (host and target)
7083 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7084 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7085 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7087 * New hosts supported (not targets)
7089 IBM RT/PC: romp-ibm-aix or rtpc
7091 * New targets supported (not hosts)
7093 AMD 29000 embedded with COFF a29k-none-coff
7094 AMD 29000 embedded with a.out a29k-none-aout
7095 Ultracomputer remote kernel debug a29k-nyu-kern
7097 * New remote interfaces
7103 *** Changes in GDB-4.0:
7107 Wide output is wrapped at good places to make the output more readable.
7109 Gdb now supports cross-debugging from a host machine of one type to a
7110 target machine of another type. Communication with the target system
7111 is over serial lines. The ``target'' command handles connecting to the
7112 remote system; the ``load'' command will download a program into the
7113 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7114 also supports debugging of realtime processes running under VxWorks,
7115 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7116 stub on the target system.
7118 New CPUs supported include the AMD 29000 and Intel 960.
7120 GDB now reads object files and symbol tables via a ``binary file''
7121 library, which allows a single copy of GDB to debug programs of multiple
7122 object file types such as a.out and coff.
7124 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7125 refcard.dvi and refcard.ps are available to format it).
7128 * Control-Variable user interface simplified
7130 All variables that control the operation of the debugger can be set
7131 by the ``set'' command, and displayed by the ``show'' command.
7133 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7134 ``Show prompt'' produces the response:
7135 Gdb's prompt is new-gdb=>.
7137 What follows are the NEW set commands. The command ``help set'' will
7138 print a complete list of old and new set commands. ``help set FOO''
7139 will give a longer description of the variable FOO. ``show'' will show
7140 all of the variable descriptions and their current settings.
7142 confirm on/off: Enables warning questions for operations that are
7143 hard to recover from, e.g. rerunning the program while
7144 it is already running. Default is ON.
7146 editing on/off: Enables EMACS style command line editing
7147 of input. Previous lines can be recalled with
7148 control-P, the current line can be edited with control-B,
7149 you can search for commands with control-R, etc.
7152 history filename NAME: NAME is where the gdb command history
7153 will be stored. The default is .gdb_history,
7154 or the value of the environment variable
7157 history size N: The size, in commands, of the command history. The
7158 default is 256, or the value of the environment variable
7161 history save on/off: If this value is set to ON, the history file will
7162 be saved after exiting gdb. If set to OFF, the
7163 file will not be saved. The default is OFF.
7165 history expansion on/off: If this value is set to ON, then csh-like
7166 history expansion will be performed on
7167 command line input. The default is OFF.
7169 radix N: Sets the default radix for input and output. It can be set
7170 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7171 in the current radix, so "set radix 10" is always a no-op.
7173 height N: This integer value is the number of lines on a page. Default
7174 is 24, the current `stty rows'' setting, or the ``li#''
7175 setting from the termcap entry matching the environment
7178 width N: This integer value is the number of characters on a line.
7179 Default is 80, the current `stty cols'' setting, or the ``co#''
7180 setting from the termcap entry matching the environment
7183 Note: ``set screensize'' is obsolete. Use ``set height'' and
7184 ``set width'' instead.
7186 print address on/off: Print memory addresses in various command displays,
7187 such as stack traces and structure values. Gdb looks
7188 more ``symbolic'' if you turn this off; it looks more
7189 ``machine level'' with it on. Default is ON.
7191 print array on/off: Prettyprint arrays. New convenient format! Default
7194 print demangle on/off: Print C++ symbols in "source" form if on,
7197 print asm-demangle on/off: Same, for assembler level printouts
7200 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7203 * Support for Epoch Environment.
7205 The epoch environment is a version of Emacs v18 with windowing. One
7206 new command, ``inspect'', is identical to ``print'', except that if you
7207 are running in the epoch environment, the value is printed in its own
7211 * Support for Shared Libraries
7213 GDB can now debug programs and core files that use SunOS shared libraries.
7214 Symbols from a shared library cannot be referenced
7215 before the shared library has been linked with the program (this
7216 happens after you type ``run'' and before the function main() is entered).
7217 At any time after this linking (including when examining core files
7218 from dynamically linked programs), gdb reads the symbols from each
7219 shared library when you type the ``sharedlibrary'' command.
7220 It can be abbreviated ``share''.
7222 sharedlibrary REGEXP: Load shared object library symbols for files
7223 matching a unix regular expression. No argument
7224 indicates to load symbols for all shared libraries.
7226 info sharedlibrary: Status of loaded shared libraries.
7231 A watchpoint stops execution of a program whenever the value of an
7232 expression changes. Checking for this slows down execution
7233 tremendously whenever you are in the scope of the expression, but is
7234 quite useful for catching tough ``bit-spreader'' or pointer misuse
7235 problems. Some machines such as the 386 have hardware for doing this
7236 more quickly, and future versions of gdb will use this hardware.
7238 watch EXP: Set a watchpoint (breakpoint) for an expression.
7240 info watchpoints: Information about your watchpoints.
7242 delete N: Deletes watchpoint number N (same as breakpoints).
7243 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7244 enable N: Re-enables watchpoint number N (same as breakpoints).
7247 * C++ multiple inheritance
7249 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7252 * C++ exception handling
7254 Gdb now supports limited C++ exception handling. Besides the existing
7255 ability to breakpoint on an exception handler, gdb can breakpoint on
7256 the raising of an exception (before the stack is peeled back to the
7259 catch FOO: If there is a FOO exception handler in the dynamic scope,
7260 set a breakpoint to catch exceptions which may be raised there.
7261 Multiple exceptions (``catch foo bar baz'') may be caught.
7263 info catch: Lists all exceptions which may be caught in the
7264 current stack frame.
7267 * Minor command changes
7269 The command ``call func (arg, arg, ...)'' now acts like the print
7270 command, except it does not print or save a value if the function's result
7271 is void. This is similar to dbx usage.
7273 The ``up'' and ``down'' commands now always print the frame they end up
7274 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7275 frames without printing.
7277 * New directory command
7279 'dir' now adds directories to the FRONT of the source search path.
7280 The path starts off empty. Source files that contain debug information
7281 about the directory in which they were compiled can be found even
7282 with an empty path; Sun CC and GCC include this information. If GDB can't
7283 find your source file in the current directory, type "dir .".
7285 * Configuring GDB for compilation
7287 For normal use, type ``./configure host''. See README or gdb.texinfo
7290 GDB now handles cross debugging. If you are remotely debugging between
7291 two different machines, type ``./configure host -target=targ''.
7292 Host is the machine where GDB will run; targ is the machine
7293 where the program that you are debugging will run.