1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * New built-in convenience variables $_gdb_major and $_gdb_minor
7 provide the GDB version. They are handy for conditionally using
8 features available only in or since specific GDB versions, in
9 scripts that should work error-free with many different versions,
10 such as in system-wide init files.
12 * GDB now supports Thread Local Storage (TLS) variables on several
13 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
14 architectures require kernel changes. TLS is not yet supported for
15 amd64 and i386 process core dumps.
17 * Support for Pointer Authentication on AArch64 Linux.
19 *** Changes in GDB 8.3
21 * GDB and GDBserver now support access to additional registers on
22 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
25 * GDB now has experimental support for the compilation and injection of
26 C++ source code into the inferior. This beta release does not include
27 support for several language features, such as templates, constructors,
30 This feature requires GCC 7.1 or higher built with libcp1.so
33 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
34 can be passed using the '[ADDRESS]:PORT' notation, or the regular
35 'ADDRESS:PORT' method.
37 * DWARF index cache: GDB can now automatically save indices of DWARF
38 symbols on disk to speed up further loading of the same binaries.
40 * Ada task switching is now supported on aarch64-elf targets when
41 debugging a program using the Ravenscar Profile. For more information,
42 see the "Tasking Support when using the Ravenscar Profile" section
43 in the GDB user manual.
45 * GDB in batch mode now exits with status 1 if the last command to be
48 * The RISC-V target now supports target descriptions.
50 * System call catchpoints now support system call aliases on FreeBSD.
51 When the ABI of a system call changes in FreeBSD, this is
52 implemented by leaving a compatibility system call using the old ABI
53 at the existing number and allocating a new system call number for
54 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
55 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
56 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
57 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
58 so that a system call catchpoint for the 'kevent' system call will
59 catch invocations of both the 'kevent' and 'freebsd11_kevent'
60 binaries. This ensures that 'kevent' system calls are caught for
61 binaries using either the old or new ABIs.
63 * Terminal styling is now available for the CLI and the TUI. GNU
64 Source Highlight can additionally be used to provide styling of
65 source code snippets. See the "set style" commands, below, for more
68 * Removed support for old demangling styles arm, edg, gnu, hp and
73 set debug compile-cplus-types
74 show debug compile-cplus-types
75 Control the display of debug output about type conversion in the
76 C++ compile feature. Commands have no effect while compiliong
81 Control whether debug output about files/functions skipping is
84 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
85 Apply a command to some frames.
86 FLAG arguments allow to control what output to produce and how to handle
87 errors raised when applying COMMAND to a frame.
90 Apply a command to all threads (ignoring errors and empty output).
91 Shortcut for 'thread apply all -s COMMAND'.
94 Apply a command to all frames (ignoring errors and empty output).
95 Shortcut for 'frame apply all -s COMMAND'.
98 Apply a command to all frames of all threads (ignoring errors and empty
100 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
102 maint set dwarf unwinders (on|off)
103 maint show dwarf unwinders
104 Control whether DWARF unwinders can be used.
107 Display a list of open files for a process.
111 Changes to the "frame", "select-frame", and "info frame" CLI commands.
112 These commands all now take a frame specification which
113 is either a frame level, or one of the keywords 'level', 'address',
114 'function', or 'view' followed by a parameter. Selecting a frame by
115 address, or viewing a frame outside the current backtrace now
116 requires the use of a keyword. Selecting a frame by level is
117 unchanged. The MI comment "-stack-select-frame" is unchanged.
119 target remote FILENAME
120 target extended-remote FILENAME
121 If FILENAME is a Unix domain socket, GDB will attempt to connect
122 to this socket instead of opening FILENAME as a character device.
124 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
125 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
126 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
127 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
128 These commands can now print only the searched entities
129 matching the provided regexp(s), giving a condition
130 on the entity names or entity types. The flag -q disables
131 printing headers or informations messages.
137 These commands now determine the syntax for the shown entities
138 according to the language chosen by `set language'. In particular,
139 `set language auto' means to automatically choose the language of
142 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
143 The 'thread apply' command accepts new FLAG arguments.
144 FLAG arguments allow to control what output to produce and how to handle
145 errors raised when applying COMMAND to a thread.
147 set tui tab-width NCHARS
148 show tui tab-width NCHARS
149 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
151 set style enabled [on|off]
153 Enable or disable terminal styling. Styling is enabled by default
154 on most hosts, but disabled by default when in batch mode.
156 set style sources [on|off]
158 Enable or disable source code styling. Source code styling is
159 enabled by default, but only takes effect if styling in general is
160 enabled, and if GDB was linked with GNU Source Highlight.
162 set style filename foreground COLOR
163 set style filename background COLOR
164 set style filename intensity VALUE
165 Control the styling of file names.
167 set style function foreground COLOR
168 set style function background COLOR
169 set style function intensity VALUE
170 Control the styling of function names.
172 set style variable foreground COLOR
173 set style variable background COLOR
174 set style variable intensity VALUE
175 Control the styling of variable names.
177 set style address foreground COLOR
178 set style address background COLOR
179 set style address intensity VALUE
180 Control the styling of addresses.
184 ** The default version of the MI interpreter is now 3 (-i=mi3).
186 ** The '-data-disassemble' MI command now accepts an '-a' option to
187 disassemble the whole function surrounding the given program
188 counter value or function name. Support for this feature can be
189 verified by using the "-list-features" command, which should
190 contain "data-disassemble-a-option".
192 ** Command responses and notifications that include a frame now include
193 the frame's architecture in a new "arch" attribute.
195 ** The output of information about multi-location breakpoints (which is
196 syntactically incorrect in MI 2) has changed in MI 3. This affects
197 the following commands and events:
201 - =breakpoint-created
202 - =breakpoint-modified
204 The -fix-multi-location-breakpoint-output command can be used to enable
205 this behavior with previous MI versions.
207 * New native configurations
209 GNU/Linux/RISC-V riscv*-*-linux*
210 FreeBSD/riscv riscv*-*-freebsd*
214 GNU/Linux/RISC-V riscv*-*-linux*
216 CSKY GNU/LINUX csky*-*-linux
217 FreeBSD/riscv riscv*-*-freebsd*
219 GNU/Linux/OpenRISC or1k*-*-linux*
223 GDB no longer supports native debugging on versions of MS-Windows
228 ** GDB no longer supports Python versions less than 2.6.
230 ** The gdb.Inferior type has a new 'progspace' property, which is the program
231 space associated to that inferior.
233 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
234 of objfiles associated to that program space.
236 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
237 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
240 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
241 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
242 correct and did not work properly.
244 ** The gdb.Value type has a new constructor, which is used to construct a
245 gdb.Value from a Python buffer object and a gdb.Type.
251 Enable or disable the undefined behavior sanitizer. This is
252 disabled by default, but passing --enable-ubsan=yes or
253 --enable-ubsan=auto to configure will enable it. Enabling this can
254 cause a performance penalty. The undefined behavior sanitizer was
255 first introduced in GCC 4.9.
257 *** Changes in GDB 8.2
259 * The 'set disassembler-options' command now supports specifying options
262 * The 'symbol-file' command now accepts an '-o' option to add a relative
263 offset to all sections.
265 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
266 a relative offset to all sections, but it allows to override the load
267 address of individual sections using '-s'.
269 * The 'add-symbol-file' command no longer requires the second argument
270 (address of the text section).
272 * The endianness used with the 'set endian auto' mode in the absence of
273 an executable selected for debugging is now the last endianness chosen
274 either by one of the 'set endian big' and 'set endian little' commands
275 or by inferring from the last executable used, rather than the startup
278 * The pager now allows a "c" response, meaning to disable the pager
279 for the rest of the current command.
281 * The commands 'info variables/functions/types' now show the source line
282 numbers of symbol definitions when available.
284 * 'info proc' now works on running processes on FreeBSD systems and core
285 files created on FreeBSD systems.
287 * C expressions can now use _Alignof, and C++ expressions can now use
290 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
291 the vector length while the process is running.
297 Control display of debugging info regarding the FreeBSD native target.
299 set|show varsize-limit
300 This new setting allows the user to control the maximum size of Ada
301 objects being printed when those objects have a variable type,
302 instead of that maximum size being hardcoded to 65536 bytes.
304 set|show record btrace cpu
305 Controls the processor to be used for enabling errata workarounds for
308 maint check libthread-db
309 Run integrity checks on the current inferior's thread debugging
312 maint set check-libthread-db (on|off)
313 maint show check-libthread-db
314 Control whether to run integrity checks on inferior specific thread
315 debugging libraries as they are loaded. The default is not to
320 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
322 ** The commands attached to a breakpoint can be set by assigning to
323 the breakpoint's "commands" field.
325 ** gdb.execute can now execute multi-line gdb commands.
327 ** The new functions gdb.convenience_variable and
328 gdb.set_convenience_variable can be used to get and set the value
329 of convenience variables.
331 ** A gdb.Parameter will no longer print the "set" help text on an
332 ordinary "set"; instead by default a "set" will be silent unless
333 the get_set_string method returns a non-empty string.
337 RiscV ELF riscv*-*-elf
339 * Removed targets and native configurations
341 m88k running OpenBSD m88*-*-openbsd*
342 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
343 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
344 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
346 * Aarch64/Linux hardware watchpoints improvements
348 Hardware watchpoints on unaligned addresses are now properly
349 supported when running Linux kernel 4.10 or higher: read and access
350 watchpoints are no longer spuriously missed, and all watchpoints
351 lengths between 1 and 8 bytes are supported. On older kernels,
352 watchpoints set on unaligned addresses are no longer missed, with
353 the tradeoff that there is a possibility of false hits being
358 --enable-codesign=CERT
359 This can be used to invoke "codesign -s CERT" after building gdb.
360 This option is useful on macOS, where code signing is required for
361 gdb to work properly.
363 --disable-gdbcli has been removed
364 This is now silently accepted, but does nothing.
366 *** Changes in GDB 8.1
368 * GDB now supports dynamically creating arbitrary register groups specified
369 in XML target descriptions. This allows for finer grain grouping of
370 registers on systems with a large amount of registers.
372 * The 'ptype' command now accepts a '/o' flag, which prints the
373 offsets and sizes of fields in a struct, like the pahole(1) tool.
375 * New "--readnever" command line option instructs GDB to not read each
376 symbol file's symbolic debug information. This makes startup faster
377 but at the expense of not being able to perform symbolic debugging.
378 This option is intended for use cases where symbolic debugging will
379 not be used, e.g., when you only need to dump the debuggee's core.
381 * GDB now uses the GNU MPFR library, if available, to emulate target
382 floating-point arithmetic during expression evaluation when the target
383 uses different floating-point formats than the host. At least version
384 3.1 of GNU MPFR is required.
386 * GDB now supports access to the guarded-storage-control registers and the
387 software-based guarded-storage broadcast control registers on IBM z14.
389 * On Unix systems, GDB now supports transmitting environment variables
390 that are to be set or unset to GDBserver. These variables will
391 affect the environment to be passed to the remote inferior.
393 To inform GDB of environment variables that are to be transmitted to
394 GDBserver, use the "set environment" command. Only user set
395 environment variables are sent to GDBserver.
397 To inform GDB of environment variables that are to be unset before
398 the remote inferior is started by the GDBserver, use the "unset
399 environment" command.
401 * Completion improvements
403 ** GDB can now complete function parameters in linespecs and
404 explicit locations without quoting. When setting breakpoints,
405 quoting around functions names to help with TAB-completion is
406 generally no longer necessary. For example, this now completes
409 (gdb) b function(in[TAB]
410 (gdb) b function(int)
412 Related, GDB is no longer confused with completing functions in
413 C++ anonymous namespaces:
416 (gdb) b (anonymous namespace)::[TAB][TAB]
417 (anonymous namespace)::a_function()
418 (anonymous namespace)::b_function()
420 ** GDB now has much improved linespec and explicit locations TAB
421 completion support, that better understands what you're
422 completing and offers better suggestions. For example, GDB no
423 longer offers data symbols as possible completions when you're
424 setting a breakpoint.
426 ** GDB now TAB-completes label symbol names.
428 ** The "complete" command now mimics TAB completion accurately.
430 * New command line options (gcore)
433 Dump all memory mappings.
435 * Breakpoints on C++ functions are now set on all scopes by default
437 By default, breakpoints on functions/methods are now interpreted as
438 specifying all functions with the given name ignoring missing
439 leading scopes (namespaces and classes).
441 For example, assuming a C++ program with symbols named:
446 both commands "break func()" and "break B::func()" set a breakpoint
449 You can use the new flag "-qualified" to override this. This makes
450 GDB interpret the specified function name as a complete
451 fully-qualified name instead. For example, using the same C++
452 program, the "break -q B::func" command sets a breakpoint on
453 "B::func", only. A parameter has been added to the Python
454 gdb.Breakpoint constructor to achieve the same result when creating
455 a breakpoint from Python.
457 * Breakpoints on functions marked with C++ ABI tags
459 GDB can now set breakpoints on functions marked with C++ ABI tags
460 (e.g., [abi:cxx11]). See here for a description of ABI tags:
461 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
463 Functions with a C++11 abi tag are demangled/displayed like this:
465 function[abi:cxx11](int)
468 You can now set a breakpoint on such functions simply as if they had
471 (gdb) b function(int)
473 Or if you need to disambiguate between tags, like:
475 (gdb) b function[abi:other_tag](int)
477 Tab completion was adjusted accordingly as well.
481 ** New events gdb.new_inferior, gdb.inferior_deleted, and
482 gdb.new_thread are emitted. See the manual for further
483 description of these.
485 ** A new function, "gdb.rbreak" has been added to the Python API.
486 This function allows the setting of a large number of breakpoints
487 via a regex pattern in Python. See the manual for further details.
489 ** Python breakpoints can now accept explicit locations. See the
490 manual for a further description of this feature.
493 * New features in the GDB remote stub, GDBserver
495 ** GDBserver is now able to start inferior processes with a
496 specified initial working directory.
498 The user can set the desired working directory to be used from
499 GDB using the new "set cwd" command.
501 ** New "--selftest" command line option runs some GDBserver self
502 tests. These self tests are disabled in releases.
504 ** On Unix systems, GDBserver now does globbing expansion and variable
505 substitution in inferior command line arguments.
507 This is done by starting inferiors using a shell, like GDB does.
508 See "set startup-with-shell" in the user manual for how to disable
509 this from GDB when using "target extended-remote". When using
510 "target remote", you can disable the startup with shell by using the
511 new "--no-startup-with-shell" GDBserver command line option.
513 ** On Unix systems, GDBserver now supports receiving environment
514 variables that are to be set or unset from GDB. These variables
515 will affect the environment to be passed to the inferior.
517 * When catching an Ada exception raised with a message, GDB now prints
518 the message in the catchpoint hit notification. In GDB/MI mode, that
519 information is provided as an extra field named "exception-message"
520 in the *stopped notification.
522 * Trait objects can now be inspected When debugging Rust code. This
523 requires compiler support which will appear in Rust 1.24.
527 QEnvironmentHexEncoded
528 Inform GDBserver of an environment variable that is to be passed to
529 the inferior when starting it.
532 Inform GDBserver of an environment variable that is to be unset
533 before starting the remote inferior.
536 Inform GDBserver that the environment should be reset (i.e.,
537 user-set environment variables should be unset).
540 Indicates whether the inferior must be started with a shell or not.
543 Tell GDBserver that the inferior to be started should use a specific
546 * The "maintenance print c-tdesc" command now takes an optional
547 argument which is the file name of XML target description.
549 * The "maintenance selftest" command now takes an optional argument to
550 filter the tests to be run.
552 * The "enable", and "disable" commands now accept a range of
553 breakpoint locations, e.g. "enable 1.3-5".
558 Set and show the current working directory for the inferior.
561 Set and show compilation command used for compiling and injecting code
562 with the 'compile' commands.
564 set debug separate-debug-file
565 show debug separate-debug-file
566 Control the display of debug output about separate debug file search.
568 set dump-excluded-mappings
569 show dump-excluded-mappings
570 Control whether mappings marked with the VM_DONTDUMP flag should be
571 dumped when generating a core file.
574 List the registered selftests.
577 Start the debugged program stopping at the first instruction.
580 Control display of debugging messages related to OpenRISC targets.
582 set|show print type nested-type-limit
583 Set and show the limit of nesting level for nested types that the
584 type printer will show.
586 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
589 * Safer/improved support for debugging with no debug info
591 GDB no longer assumes functions with no debug information return
594 This means that GDB now refuses to call such functions unless you
595 tell it the function's type, by either casting the call to the
596 declared return type, or by casting the function to a function
597 pointer of the right type, and calling that:
599 (gdb) p getenv ("PATH")
600 'getenv' has unknown return type; cast the call to its declared return type
601 (gdb) p (char *) getenv ("PATH")
602 $1 = 0x7fffffffe "/usr/local/bin:/"...
603 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
604 $2 = 0x7fffffffe "/usr/local/bin:/"...
606 Similarly, GDB no longer assumes that global variables with no debug
607 info have type 'int', and refuses to print the variable's value
608 unless you tell it the variable's type:
611 'var' has unknown type; cast it to its declared type
615 * New native configurations
617 FreeBSD/aarch64 aarch64*-*-freebsd*
618 FreeBSD/arm arm*-*-freebsd*
622 FreeBSD/aarch64 aarch64*-*-freebsd*
623 FreeBSD/arm arm*-*-freebsd*
624 OpenRISC ELF or1k*-*-elf
626 * Removed targets and native configurations
628 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
630 *** Changes in GDB 8.0
632 * GDB now supports access to the PKU register on GNU/Linux. The register is
633 added by the Memory Protection Keys for Userspace feature which will be
634 available in future Intel CPUs.
636 * GDB now supports C++11 rvalue references.
640 ** New functions to start, stop and access a running btrace recording.
641 ** Rvalue references are now supported in gdb.Type.
643 * GDB now supports recording and replaying rdrand and rdseed Intel 64
646 * Building GDB and GDBserver now requires a C++11 compiler.
648 For example, GCC 4.8 or later.
650 It is no longer possible to build GDB or GDBserver with a C
651 compiler. The --disable-build-with-cxx configure option has been
654 * Building GDB and GDBserver now requires GNU make >= 3.81.
656 It is no longer supported to build GDB or GDBserver with another
657 implementation of the make program or an earlier version of GNU make.
659 * Native debugging on MS-Windows supports command-line redirection
661 Command-line arguments used for starting programs on MS-Windows can
662 now include redirection symbols supported by native Windows shells,
663 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
664 as "run", "start", and "set args", as well as the corresponding MI
667 * Support for thread names on MS-Windows.
669 GDB now catches and handles the special exception that programs
670 running on MS-Windows use to assign names to threads in the
673 * Support for Java programs compiled with gcj has been removed.
675 * User commands now accept an unlimited number of arguments.
676 Previously, only up to 10 was accepted.
678 * The "eval" command now expands user-defined command arguments.
680 This makes it easier to process a variable number of arguments:
685 eval "print $arg%d", $i
690 * Target descriptions can now describe registers for sparc32 and sparc64.
692 * GDB now supports DWARF version 5 (debug information format).
693 Its .debug_names index is not yet supported.
695 * New native configurations
697 FreeBSD/mips mips*-*-freebsd
701 Synopsys ARC arc*-*-elf32
702 FreeBSD/mips mips*-*-freebsd
704 * Removed targets and native configurations
706 Alpha running FreeBSD alpha*-*-freebsd*
707 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
712 Erases all the flash memory regions reported by the target.
714 maint print arc arc-instruction address
715 Print internal disassembler information about instruction at a given address.
719 set disassembler-options
720 show disassembler-options
721 Controls the passing of target specific information to the disassembler.
722 If it is necessary to specify more than one disassembler option then
723 multiple options can be placed together into a comma separated list.
724 The default value is the empty string. Currently, the only supported
725 targets are ARM, PowerPC and S/390.
730 Erases all the flash memory regions reported by the target. This is
731 equivalent to the CLI command flash-erase.
733 -file-list-shared-libraries
734 List the shared libraries in the program. This is
735 equivalent to the CLI command "info shared".
738 Catchpoints stopping the program when Ada exceptions are
739 handled. This is equivalent to the CLI command "catch handlers".
741 *** Changes in GDB 7.12
743 * GDB and GDBserver now build with a C++ compiler by default.
745 The --enable-build-with-cxx configure option is now enabled by
746 default. One must now explicitly configure with
747 --disable-build-with-cxx in order to build with a C compiler. This
748 option will be removed in a future release.
750 * GDBserver now supports recording btrace without maintaining an active
753 * GDB now supports a negative repeat count in the 'x' command to examine
754 memory backward from the given address. For example:
757 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
758 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
759 (gdb) x/-5i 0x0000000000400580
760 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
761 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
762 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
763 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
764 0x40057b <main(int, char**)+25>:
765 callq 0x400536 <Func1(int, char const*)>
767 * Fortran: Support structures with fields of dynamic types and
768 arrays of dynamic types.
770 * The symbol dumping maintenance commands have new syntax.
771 maint print symbols [-pc address] [--] [filename]
772 maint print symbols [-objfile objfile] [-source source] [--] [filename]
773 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
774 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
775 maint print msymbols [-objfile objfile] [--] [filename]
777 * GDB now supports multibit bitfields and enums in target register
780 * New Python-based convenience function $_as_string(val), which returns
781 the textual representation of a value. This function is especially
782 useful to obtain the text label of an enum value.
784 * Intel MPX bound violation handling.
786 Segmentation faults caused by a Intel MPX boundary violation
787 now display the kind of violation (upper or lower), the memory
788 address accessed and the memory bounds, along with the usual
789 signal received and code location.
793 Program received signal SIGSEGV, Segmentation fault
794 Upper bound violation while accessing address 0x7fffffffc3b3
795 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
796 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
798 * Rust language support.
799 GDB now supports debugging programs written in the Rust programming
800 language. See https://www.rust-lang.org/ for more information about
803 * Support for running interpreters on specified input/output devices
805 GDB now supports a new mechanism that allows frontends to provide
806 fully featured GDB console views, as a better alternative to
807 building such views on top of the "-interpreter-exec console"
808 command. See the new "new-ui" command below. With that command,
809 frontends can now start GDB in the traditional command-line mode
810 running in an embedded terminal emulator widget, and create a
811 separate MI interpreter running on a specified i/o device. In this
812 way, GDB handles line editing, history, tab completion, etc. in the
813 console all by itself, and the GUI uses the separate MI interpreter
814 for its own control and synchronization, invisible to the command
817 * The "catch syscall" command catches groups of related syscalls.
819 The "catch syscall" command now supports catching a group of related
820 syscalls using the 'group:' or 'g:' prefix.
825 skip -gfile file-glob-pattern
826 skip -function function
827 skip -rfunction regular-expression
828 A generalized form of the skip command, with new support for
829 glob-style file names and regular expressions for function names.
830 Additionally, a file spec and a function spec may now be combined.
832 maint info line-table REGEXP
833 Display the contents of GDB's internal line table data struture.
836 Run any GDB unit tests that were compiled in.
839 Start a new user interface instance running INTERP as interpreter,
840 using the TTY file for input/output.
844 ** gdb.Breakpoint objects have a new attribute "pending", which
845 indicates whether the breakpoint is pending.
846 ** Three new breakpoint-related events have been added:
847 gdb.breakpoint_created, gdb.breakpoint_modified, and
848 gdb.breakpoint_deleted.
851 Signal ("set") the given MS-Windows event object. This is used in
852 conjunction with the Windows JIT debugging (AeDebug) support, where
853 the OS suspends a crashing process until a debugger can attach to
854 it. Resuming the crashing process, in order to debug it, is done by
857 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
858 was added in GDBserver, including JIT compiling fast tracepoint's
859 conditional expression bytecode into native code.
861 * Support for various remote target protocols and ROM monitors has
864 target m32rsdi Remote M32R debugging over SDI
865 target mips MIPS remote debugging protocol
866 target pmon PMON ROM monitor
867 target ddb NEC's DDB variant of PMON for Vr4300
868 target rockhopper NEC RockHopper variant of PMON
869 target lsi LSI variant of PMO
871 * Support for tracepoints and fast tracepoints on powerpc-linux,
872 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
873 including JIT compiling fast tracepoint's conditional expression
874 bytecode into native code.
876 * MI async record =record-started now includes the method and format used for
877 recording. For example:
879 =record-started,thread-group="i1",method="btrace",format="bts"
881 * MI async record =thread-selected now includes the frame field. For example:
883 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
887 Andes NDS32 nds32*-*-elf
889 *** Changes in GDB 7.11
891 * GDB now supports debugging kernel-based threads on FreeBSD.
893 * Per-inferior thread numbers
895 Thread numbers are now per inferior instead of global. If you're
896 debugging multiple inferiors, GDB displays thread IDs using a
897 qualified INF_NUM.THR_NUM form. For example:
901 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
902 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
903 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
904 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
906 As consequence, thread numbers as visible in the $_thread
907 convenience variable and in Python's InferiorThread.num attribute
908 are no longer unique between inferiors.
910 GDB now maintains a second thread ID per thread, referred to as the
911 global thread ID, which is the new equivalent of thread numbers in
912 previous releases. See also $_gthread below.
914 For backwards compatibility, MI's thread IDs always refer to global
917 * Commands that accept thread IDs now accept the qualified
918 INF_NUM.THR_NUM form as well. For example:
921 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
924 * In commands that accept a list of thread IDs, you can now refer to
925 all threads of an inferior using a star wildcard. GDB accepts
926 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
927 refer to all threads of the current inferior. For example, "info
930 * You can use "info threads -gid" to display the global thread ID of
933 * The new convenience variable $_gthread holds the global number of
936 * The new convenience variable $_inferior holds the number of the
939 * GDB now displays the ID and name of the thread that hit a breakpoint
940 or received a signal, if your program is multi-threaded. For
943 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
944 Thread 1 "main" received signal SIGINT, Interrupt.
946 * Record btrace now supports non-stop mode.
948 * Support for tracepoints on aarch64-linux was added in GDBserver.
950 * The 'record instruction-history' command now indicates speculative execution
951 when using the Intel Processor Trace recording format.
953 * GDB now allows users to specify explicit locations, bypassing
954 the linespec parser. This feature is also available to GDB/MI
957 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
958 GDB now is able to debug both AArch64 applications and ARM applications
961 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
962 including JIT compiling fast tracepoint's conditional expression bytecode
965 * GDB now supports displaced stepping on AArch64 GNU/Linux.
967 * "info threads", "info inferiors", "info display", "info checkpoints"
968 and "maint info program-spaces" now list the corresponding items in
969 ascending ID order, for consistency with all other "info" commands.
971 * In Ada, the overloads selection menu has been enhanced to display the
972 parameter types and the return types for the matching overloaded subprograms.
976 maint set target-non-stop (on|off|auto)
977 maint show target-non-stop
978 Control whether GDB targets always operate in non-stop mode even if
979 "set non-stop" is "off". The default is "auto", meaning non-stop
980 mode is enabled if supported by the target.
982 maint set bfd-sharing
983 maint show bfd-sharing
984 Control the reuse of bfd objects.
988 Control display of debugging info regarding bfd caching.
992 Control display of debugging info regarding FreeBSD threads.
994 set remote multiprocess-extensions-packet
995 show remote multiprocess-extensions-packet
996 Set/show the use of the remote protocol multiprocess extensions.
998 set remote thread-events
999 show remote thread-events
1000 Set/show the use of thread create/exit events.
1002 set ada print-signatures on|off
1003 show ada print-signatures"
1004 Control whether parameter types and return types are displayed in overloads
1005 selection menus. It is activaled (@code{on}) by default.
1009 Controls the maximum size of memory, in bytes, that GDB will
1010 allocate for value contents. Prevents incorrect programs from
1011 causing GDB to allocate overly large buffers. Default is 64k.
1013 * The "disassemble" command accepts a new modifier: /s.
1014 It prints mixed source+disassembly like /m with two differences:
1015 - disassembled instructions are now printed in program order, and
1016 - and source for all relevant files is now printed.
1017 The "/m" option is now considered deprecated: its "source-centric"
1018 output hasn't proved useful in practice.
1020 * The "record instruction-history" command accepts a new modifier: /s.
1021 It behaves exactly like /m and prints mixed source+disassembly.
1023 * The "set scheduler-locking" command supports a new mode "replay".
1024 It behaves like "off" in record mode and like "on" in replay mode.
1026 * Support for various ROM monitors has been removed:
1028 target dbug dBUG ROM monitor for Motorola ColdFire
1029 target picobug Motorola picobug monitor
1030 target dink32 DINK32 ROM monitor for PowerPC
1031 target m32r Renesas M32R/D ROM monitor
1032 target mon2000 mon2000 ROM monitor
1033 target ppcbug PPCBUG ROM monitor for PowerPC
1035 * Support for reading/writing memory and extracting values on architectures
1036 whose memory is addressable in units of any integral multiple of 8 bits.
1039 Allows to break when an Ada exception is handled.
1041 * New remote packets
1044 Indicates that an exec system call was executed.
1046 exec-events feature in qSupported
1047 The qSupported packet allows GDB to request support for exec
1048 events using the new 'gdbfeature' exec-event, and the qSupported
1049 response can contain the corresponding 'stubfeature'. Set and
1050 show commands can be used to display whether these features are enabled.
1053 Equivalent to interrupting with the ^C character, but works in
1056 thread created stop reason (T05 create:...)
1057 Indicates that the thread was just created and is stopped at entry.
1059 thread exit stop reply (w exitcode;tid)
1060 Indicates that the thread has terminated.
1063 Enables/disables thread create and exit event reporting. For
1064 example, this is used in non-stop mode when GDB stops a set of
1065 threads and synchronously waits for the their corresponding stop
1066 replies. Without exit events, if one of the threads exits, GDB
1067 would hang forever not knowing that it should no longer expect a
1068 stop for that same thread.
1071 Indicates that there are no resumed threads left in the target (all
1072 threads are stopped). The remote stub reports support for this stop
1073 reply to GDB's qSupported query.
1076 Enables/disables catching syscalls from the inferior process.
1077 The remote stub reports support for this packet to GDB's qSupported query.
1079 syscall_entry stop reason
1080 Indicates that a syscall was just called.
1082 syscall_return stop reason
1083 Indicates that a syscall just returned.
1085 * Extended-remote exec events
1087 ** GDB now has support for exec events on extended-remote Linux targets.
1088 For such targets with Linux kernels 2.5.46 and later, this enables
1089 follow-exec-mode and exec catchpoints.
1091 set remote exec-event-feature-packet
1092 show remote exec-event-feature-packet
1093 Set/show the use of the remote exec event feature.
1095 * Thread names in remote protocol
1097 The reply to qXfer:threads:read may now include a name attribute for each
1100 * Target remote mode fork and exec events
1102 ** GDB now has support for fork and exec events on target remote mode
1103 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1104 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1105 fork and exec catchpoints.
1107 * Remote syscall events
1109 ** GDB now has support for catch syscall on remote Linux targets,
1110 currently enabled on x86/x86_64 architectures.
1112 set remote catch-syscall-packet
1113 show remote catch-syscall-packet
1114 Set/show the use of the remote catch syscall feature.
1118 ** The -var-set-format command now accepts the zero-hexadecimal
1119 format. It outputs data in hexadecimal format with zero-padding on the
1124 ** gdb.InferiorThread objects have a new attribute "global_num",
1125 which refers to the thread's global thread ID. The existing
1126 "num" attribute now refers to the thread's per-inferior number.
1127 See "Per-inferior thread numbers" above.
1128 ** gdb.InferiorThread objects have a new attribute "inferior", which
1129 is the Inferior object the thread belongs to.
1131 *** Changes in GDB 7.10
1133 * Support for process record-replay and reverse debugging on aarch64*-linux*
1134 targets has been added. GDB now supports recording of A64 instruction set
1135 including advance SIMD instructions.
1137 * Support for Sun's version of the "stabs" debug file format has been removed.
1139 * GDB now honors the content of the file /proc/PID/coredump_filter
1140 (PID is the process ID) on GNU/Linux systems. This file can be used
1141 to specify the types of memory mappings that will be included in a
1142 corefile. For more information, please refer to the manual page of
1143 "core(5)". GDB also has a new command: "set use-coredump-filter
1144 on|off". It allows to set whether GDB will read the content of the
1145 /proc/PID/coredump_filter file when generating a corefile.
1147 * The "info os" command on GNU/Linux can now display information on
1149 "info os cpus" Listing of all cpus/cores on the system
1151 * GDB has two new commands: "set serial parity odd|even|none" and
1152 "show serial parity". These allows to set or show parity for the
1155 * The "info source" command now displays the producer string if it was
1156 present in the debug info. This typically includes the compiler version
1157 and may include things like its command line arguments.
1159 * The "info dll", an alias of the "info sharedlibrary" command,
1160 is now available on all platforms.
1162 * Directory names supplied to the "set sysroot" commands may be
1163 prefixed with "target:" to tell GDB to access shared libraries from
1164 the target system, be it local or remote. This replaces the prefix
1165 "remote:". The default sysroot has been changed from "" to
1166 "target:". "remote:" is automatically converted to "target:" for
1167 backward compatibility.
1169 * The system root specified by "set sysroot" will be prepended to the
1170 filename of the main executable (if reported to GDB as absolute by
1171 the operating system) when starting processes remotely, and when
1172 attaching to already-running local or remote processes.
1174 * GDB now supports automatic location and retrieval of executable
1175 files from remote targets. Remote debugging can now be initiated
1176 using only a "target remote" or "target extended-remote" command
1177 (no "set sysroot" or "file" commands are required). See "New remote
1180 * The "dump" command now supports verilog hex format.
1182 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1184 * On GNU/Linux, GDB and gdbserver are now able to access executable
1185 and shared library files without a "set sysroot" command when
1186 attaching to processes running in different mount namespaces from
1187 the debugger. This makes it possible to attach to processes in
1188 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1189 See "New remote packets" below.
1191 * The "tui reg" command now provides completion for all of the
1192 available register groups, including target specific groups.
1194 * The HISTSIZE environment variable is no longer read when determining
1195 the size of GDB's command history. GDB now instead reads the dedicated
1196 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1197 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1202 ** Memory ports can now be unbuffered.
1206 ** gdb.Objfile objects have a new attribute "username",
1207 which is the name of the objfile as specified by the user,
1208 without, for example, resolving symlinks.
1209 ** You can now write frame unwinders in Python.
1210 ** gdb.Type objects have a new method "optimized_out",
1211 returning optimized out gdb.Value instance of this type.
1212 ** gdb.Value objects have new methods "reference_value" and
1213 "const_value" which return a reference to the value and a
1214 "const" version of the value respectively.
1218 maint print symbol-cache
1219 Print the contents of the symbol cache.
1221 maint print symbol-cache-statistics
1222 Print statistics of symbol cache usage.
1224 maint flush-symbol-cache
1225 Flush the contents of the symbol cache.
1229 Start branch trace recording using Branch Trace Store (BTS) format.
1232 Evaluate expression by using the compiler and print result.
1236 Explicit commands for enabling and disabling tui mode.
1239 set mpx bound on i386 and amd64
1240 Support for bound table investigation on Intel MPX enabled applications.
1244 Start branch trace recording using Intel Processor Trace format.
1247 Print information about branch tracing internals.
1249 maint btrace packet-history
1250 Print the raw branch tracing data.
1252 maint btrace clear-packet-history
1253 Discard the stored raw branch tracing data.
1256 Discard all branch tracing data. It will be fetched and processed
1257 anew by the next "record" command.
1262 Renamed from "set debug dwarf2-die".
1263 show debug dwarf-die
1264 Renamed from "show debug dwarf2-die".
1266 set debug dwarf-read
1267 Renamed from "set debug dwarf2-read".
1268 show debug dwarf-read
1269 Renamed from "show debug dwarf2-read".
1271 maint set dwarf always-disassemble
1272 Renamed from "maint set dwarf2 always-disassemble".
1273 maint show dwarf always-disassemble
1274 Renamed from "maint show dwarf2 always-disassemble".
1276 maint set dwarf max-cache-age
1277 Renamed from "maint set dwarf2 max-cache-age".
1278 maint show dwarf max-cache-age
1279 Renamed from "maint show dwarf2 max-cache-age".
1281 set debug dwarf-line
1282 show debug dwarf-line
1283 Control display of debugging info regarding DWARF line processing.
1286 show max-completions
1287 Set the maximum number of candidates to be considered during
1288 completion. The default value is 200. This limit allows GDB
1289 to avoid generating large completion lists, the computation of
1290 which can cause the debugger to become temporarily unresponsive.
1292 set history remove-duplicates
1293 show history remove-duplicates
1294 Control the removal of duplicate history entries.
1296 maint set symbol-cache-size
1297 maint show symbol-cache-size
1298 Control the size of the symbol cache.
1300 set|show record btrace bts buffer-size
1301 Set and show the size of the ring buffer used for branch tracing in
1303 The obtained size may differ from the requested size. Use "info
1304 record" to see the obtained buffer size.
1306 set debug linux-namespaces
1307 show debug linux-namespaces
1308 Control display of debugging info regarding Linux namespaces.
1310 set|show record btrace pt buffer-size
1311 Set and show the size of the ring buffer used for branch tracing in
1312 Intel Processor Trace format.
1313 The obtained size may differ from the requested size. Use "info
1314 record" to see the obtained buffer size.
1316 maint set|show btrace pt skip-pad
1317 Set and show whether PAD packets are skipped when computing the
1320 * The command 'thread apply all' can now support new option '-ascending'
1321 to call its specified command for all threads in ascending order.
1323 * Python/Guile scripting
1325 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1326 special section named `.debug_gdb_scripts'.
1328 * New remote packets
1330 qXfer:btrace-conf:read
1331 Return the branch trace configuration for the current thread.
1333 Qbtrace-conf:bts:size
1334 Set the requested ring buffer size for branch tracing in BTS format.
1337 Enable Intel Procesor Trace-based branch tracing for the current
1338 process. The remote stub reports support for this packet to GDB's
1341 Qbtrace-conf:pt:size
1342 Set the requested ring buffer size for branch tracing in Intel Processor
1346 Indicates a memory breakpoint instruction was executed, irrespective
1347 of whether it was GDB that planted the breakpoint or the breakpoint
1348 is hardcoded in the program. This is required for correct non-stop
1352 Indicates the target stopped for a hardware breakpoint. This is
1353 required for correct non-stop mode operation.
1356 Return information about files on the remote system.
1358 qXfer:exec-file:read
1359 Return the full absolute name of the file that was executed to
1360 create a process running on the remote system.
1363 Select the filesystem on which vFile: operations with filename
1364 arguments will operate. This is required for GDB to be able to
1365 access files on remote targets where the remote stub does not
1366 share a common filesystem with the inferior(s).
1369 Indicates that a fork system call was executed.
1372 Indicates that a vfork system call was executed.
1374 vforkdone stop reason
1375 Indicates that a vfork child of the specified process has executed
1376 an exec or exit, allowing the vfork parent to resume execution.
1378 fork-events and vfork-events features in qSupported
1379 The qSupported packet allows GDB to request support for fork and
1380 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1381 and the qSupported response can contain the corresponding
1382 'stubfeatures'. Set and show commands can be used to display
1383 whether these features are enabled.
1385 * Extended-remote fork events
1387 ** GDB now has support for fork events on extended-remote Linux
1388 targets. For targets with Linux kernels 2.5.60 and later, this
1389 enables follow-fork-mode and detach-on-fork for both fork and
1390 vfork, as well as fork and vfork catchpoints.
1392 * The info record command now shows the recording format and the
1393 branch tracing configuration for the current thread when using
1394 the btrace record target.
1395 For the BTS format, it shows the ring buffer size.
1397 * GDB now has support for DTrace USDT (Userland Static Defined
1398 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1400 * GDB now supports access to vector registers on S/390 GNU/Linux
1403 * Removed command line options
1405 -xdb HP-UX XDB compatibility mode.
1407 * Removed targets and native configurations
1409 HP/PA running HP-UX hppa*-*-hpux*
1410 Itanium running HP-UX ia64-*-hpux*
1412 * New configure options
1415 This configure option allows the user to build GDB with support for
1416 Intel Processor Trace (default: auto). This requires libipt.
1418 --with-libipt-prefix=PATH
1419 Specify the path to the version of libipt that GDB should use.
1420 $PATH/include should contain the intel-pt.h header and
1421 $PATH/lib should contain the libipt.so library.
1423 *** Changes in GDB 7.9.1
1427 ** Xmethods can now specify a result type.
1429 *** Changes in GDB 7.9
1431 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1435 ** You can now access frame registers from Python scripts.
1436 ** New attribute 'producer' for gdb.Symtab objects.
1437 ** gdb.Objfile objects have a new attribute "progspace",
1438 which is the gdb.Progspace object of the containing program space.
1439 ** gdb.Objfile objects have a new attribute "owner".
1440 ** gdb.Objfile objects have a new attribute "build_id",
1441 which is the build ID generated when the file was built.
1442 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1443 ** A new event "gdb.clear_objfiles" has been added, triggered when
1444 selecting a new file to debug.
1445 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1446 ** New function gdb.lookup_objfile.
1448 New events which are triggered when GDB modifies the state of the
1451 ** gdb.events.inferior_call_pre: Function call is about to be made.
1452 ** gdb.events.inferior_call_post: Function call has just been made.
1453 ** gdb.events.memory_changed: A memory location has been altered.
1454 ** gdb.events.register_changed: A register has been altered.
1456 * New Python-based convenience functions:
1458 ** $_caller_is(name [, number_of_frames])
1459 ** $_caller_matches(regexp [, number_of_frames])
1460 ** $_any_caller_is(name [, number_of_frames])
1461 ** $_any_caller_matches(regexp [, number_of_frames])
1463 * GDB now supports the compilation and injection of source code into
1464 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1465 to compile the source code to object code, and if successful, inject
1466 and execute that code within the current context of the inferior.
1467 Currently the C language is supported. The commands used to
1468 interface with this new feature are:
1470 compile code [-raw|-r] [--] [source code]
1471 compile file [-raw|-r] filename
1475 demangle [-l language] [--] name
1476 Demangle "name" in the specified language, or the current language
1477 if elided. This command is renamed from the "maint demangle" command.
1478 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1479 as "maint demangler-warning".
1481 queue-signal signal-name-or-number
1482 Queue a signal to be delivered to the thread when it is resumed.
1484 add-auto-load-scripts-directory directory
1485 Add entries to the list of directories from which to load auto-loaded
1488 maint print user-registers
1489 List all currently available "user" registers.
1491 compile code [-r|-raw] [--] [source code]
1492 Compile, inject, and execute in the inferior the executable object
1493 code produced by compiling the provided source code.
1495 compile file [-r|-raw] filename
1496 Compile and inject into the inferior the executable object code
1497 produced by compiling the source code stored in the filename
1500 * On resume, GDB now always passes the signal the program had stopped
1501 for to the thread the signal was sent to, even if the user changed
1502 threads before resuming. Previously GDB would often (but not
1503 always) deliver the signal to the thread that happens to be current
1506 * Conversely, the "signal" command now consistently delivers the
1507 requested signal to the current thread. GDB now asks for
1508 confirmation if the program had stopped for a signal and the user
1509 switched threads meanwhile.
1511 * "breakpoint always-inserted" modes "off" and "auto" merged.
1513 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1514 won't remove breakpoints from the target until all threads stop,
1515 even in non-stop mode. The "auto" mode has been removed, and "off"
1516 is now the default mode.
1520 set debug symbol-lookup
1521 show debug symbol-lookup
1522 Control display of debugging info regarding symbol lookup.
1526 ** The -list-thread-groups command outputs an exit-code field for
1527 inferiors that have exited.
1531 MIPS SDE mips*-sde*-elf*
1535 Support for these obsolete configurations has been removed.
1537 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1538 SGI Irix-5.x mips-*-irix5*
1539 SGI Irix-6.x mips-*-irix6*
1540 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1541 VAX running Ultrix vax-*-ultrix*
1543 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1544 and "assf"), have been removed. Use the "sharedlibrary" command, or
1545 its alias "share", instead.
1547 *** Changes in GDB 7.8
1549 * New command line options
1552 This is an alias for the --data-directory option.
1554 * GDB supports printing and modifying of variable length automatic arrays
1555 as specified in ISO C99.
1557 * The ARM simulator now supports instruction level tracing
1558 with or without disassembly.
1562 GDB now has support for scripting using Guile. Whether this is
1563 available is determined at configure time.
1564 Guile version 2.0 or greater is required.
1565 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1567 * New commands (for set/show, see "New options" below)
1571 Invoke CODE by passing it to the Guile interpreter.
1575 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1577 info auto-load guile-scripts [regexp]
1578 Print the list of automatically loaded Guile scripts.
1580 * The source command is now capable of sourcing Guile scripts.
1581 This feature is dependent on the debugger being built with Guile support.
1585 set print symbol-loading (off|brief|full)
1586 show print symbol-loading
1587 Control whether to print informational messages when loading symbol
1588 information for a file. The default is "full", but when debugging
1589 programs with large numbers of shared libraries the amount of output
1590 becomes less useful.
1592 set guile print-stack (none|message|full)
1593 show guile print-stack
1594 Show a stack trace when an error is encountered in a Guile script.
1596 set auto-load guile-scripts (on|off)
1597 show auto-load guile-scripts
1598 Control auto-loading of Guile script files.
1600 maint ada set ignore-descriptive-types (on|off)
1601 maint ada show ignore-descriptive-types
1602 Control whether the debugger should ignore descriptive types in Ada
1603 programs. The default is not to ignore the descriptive types. See
1604 the user manual for more details on descriptive types and the intended
1605 usage of this option.
1607 set auto-connect-native-target
1609 Control whether GDB is allowed to automatically connect to the
1610 native target for the run, attach, etc. commands when not connected
1611 to any target yet. See also "target native" below.
1613 set record btrace replay-memory-access (read-only|read-write)
1614 show record btrace replay-memory-access
1615 Control what memory accesses are allowed during replay.
1617 maint set target-async (on|off)
1618 maint show target-async
1619 This controls whether GDB targets operate in synchronous or
1620 asynchronous mode. Normally the default is asynchronous, if it is
1621 available; but this can be changed to more easily debug problems
1622 occurring only in synchronous mode.
1624 set mi-async (on|off)
1626 Control whether MI asynchronous mode is preferred. This supersedes
1627 "set target-async" of previous GDB versions.
1629 * "set target-async" is deprecated as a CLI option and is now an alias
1630 for "set mi-async" (only puts MI into async mode).
1632 * Background execution commands (e.g., "c&", "s&", etc.) are now
1633 possible ``out of the box'' if the target supports them. Previously
1634 the user would need to explicitly enable the possibility with the
1635 "set target-async on" command.
1637 * New features in the GDB remote stub, GDBserver
1639 ** New option --debug-format=option1[,option2,...] allows one to add
1640 additional text to each output. At present only timestamps
1641 are supported: --debug-format=timestamps.
1642 Timestamps can also be turned on with the
1643 "monitor set debug-format timestamps" command from GDB.
1645 * The 'record instruction-history' command now starts counting instructions
1646 at one. This also affects the instruction ranges reported by the
1647 'record function-call-history' command when given the /i modifier.
1649 * The command 'record function-call-history' supports a new modifier '/c' to
1650 indent the function names based on their call stack depth.
1651 The fields for the '/i' and '/l' modifier have been reordered.
1652 The source line range is now prefixed with 'at'.
1653 The instruction range is now prefixed with 'inst'.
1654 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1655 "record instruction-history" and "list" commands.
1657 * The ranges given as arguments to the 'record function-call-history' and
1658 'record instruction-history' commands are now inclusive.
1660 * The btrace record target now supports the 'record goto' command.
1661 For locations inside the execution trace, the back trace is computed
1662 based on the information stored in the execution trace.
1664 * The btrace record target supports limited reverse execution and replay.
1665 The target does not record data and therefore does not allow reading
1666 memory or registers.
1668 * The "catch syscall" command now works on s390*-linux* targets.
1670 * The "compare-sections" command is no longer specific to target
1671 remote. It now works with all targets.
1673 * All native targets are now consistently called "native".
1674 Consequently, the "target child", "target GNU", "target djgpp",
1675 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1676 commands have been replaced with "target native". The QNX/NTO port
1677 leaves the "procfs" target in place and adds a "native" target for
1678 consistency with other ports. The impact on users should be minimal
1679 as these commands previously either throwed an error, or were
1680 no-ops. The target's name is visible in the output of the following
1681 commands: "help target", "info target", "info files", "maint print
1684 * The "target native" command now connects to the native target. This
1685 can be used to launch native programs even when "set
1686 auto-connect-native-target" is set to off.
1688 * GDB now supports access to Intel MPX registers on GNU/Linux.
1690 * Support for Intel AVX-512 registers on GNU/Linux.
1691 Support displaying and modifying Intel AVX-512 registers
1692 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1694 * New remote packets
1696 qXfer:btrace:read's annex
1697 The qXfer:btrace:read packet supports a new annex 'delta' to read
1698 branch trace incrementally.
1702 ** Valid Python operations on gdb.Value objects representing
1703 structs/classes invoke the corresponding overloaded operators if
1705 ** New `Xmethods' feature in the Python API. Xmethods are
1706 additional methods or replacements for existing methods of a C++
1707 class. This feature is useful for those cases where a method
1708 defined in C++ source code could be inlined or optimized out by
1709 the compiler, making it unavailable to GDB.
1712 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1714 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1715 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1716 its alias "share", instead.
1718 * The commands "set remotebaud" and "show remotebaud" are no longer
1719 supported. Use "set serial baud" and "show serial baud" (respectively)
1724 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1725 target-async". The latter is left as a deprecated alias of the
1726 former for backward compatibility. If the target supports it,
1727 CLI background execution commands are now always possible by
1728 default, independently of whether the frontend stated a
1729 preference for asynchronous execution with "-gdb-set mi-async".
1730 Previously "-gdb-set target-async off" affected both MI execution
1731 commands and CLI execution commands.
1733 *** Changes in GDB 7.7
1735 * Improved support for process record-replay and reverse debugging on
1736 arm*-linux* targets. Support for thumb32 and syscall instruction
1737 recording has been added.
1739 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1741 * GDB now supports Fission DWP file format version 2.
1742 http://gcc.gnu.org/wiki/DebugFission
1744 * New convenience function "$_isvoid", to check whether an expression
1745 is void. A void expression is an expression where the type of the
1746 result is "void". For example, some convenience variables may be
1747 "void" when evaluated (e.g., "$_exitcode" before the execution of
1748 the program being debugged; or an undefined convenience variable).
1749 Another example, when calling a function whose return type is
1752 * The "maintenance print objfiles" command now takes an optional regexp.
1754 * The "catch syscall" command now works on arm*-linux* targets.
1756 * GDB now consistently shows "<not saved>" when printing values of
1757 registers the debug info indicates have not been saved in the frame
1758 and there's nowhere to retrieve them from
1759 (callee-saved/call-clobbered registers):
1764 (gdb) info registers rax
1767 Before, the former would print "<optimized out>", and the latter
1768 "*value not available*".
1770 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1775 ** Frame filters and frame decorators have been added.
1776 ** Temporary breakpoints are now supported.
1777 ** Line tables representation has been added.
1778 ** New attribute 'parent_type' for gdb.Field objects.
1779 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1780 ** New attribute 'name' for gdb.Type objects.
1784 Nios II ELF nios2*-*-elf
1785 Nios II GNU/Linux nios2*-*-linux
1786 Texas Instruments MSP430 msp430*-*-elf
1788 * Removed native configurations
1790 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1791 been removed. ELF variants of these configurations are kept supported.
1793 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1794 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1795 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1796 i[34567]86-*-openbsd3.[0-3]
1797 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1798 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1799 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1803 Like "catch throw", but catches a re-thrown exception.
1804 maint check-psymtabs
1805 Renamed from old "maint check-symtabs".
1807 Perform consistency checks on symtabs.
1808 maint expand-symtabs
1809 Expand symtabs matching an optional regexp.
1812 Display the details of GDB configure-time options.
1814 maint set|show per-command
1815 maint set|show per-command space
1816 maint set|show per-command time
1817 maint set|show per-command symtab
1818 Enable display of per-command gdb resource usage.
1820 remove-symbol-file FILENAME
1821 remove-symbol-file -a ADDRESS
1822 Remove a symbol file added via add-symbol-file. The file to remove
1823 can be identified by its filename or by an address that lies within
1824 the boundaries of this symbol file in memory.
1827 info exceptions REGEXP
1828 Display the list of Ada exceptions defined in the program being
1829 debugged. If provided, only the exceptions whose names match REGEXP
1834 set debug symfile off|on
1836 Control display of debugging info regarding reading symbol files and
1837 symbol tables within those files
1839 set print raw frame-arguments
1840 show print raw frame-arguments
1841 Set/show whether to print frame arguments in raw mode,
1842 disregarding any defined pretty-printers.
1844 set remote trace-status-packet
1845 show remote trace-status-packet
1846 Set/show the use of remote protocol qTStatus packet.
1850 Control display of debugging messages related to Nios II targets.
1854 Control whether target-assisted range stepping is enabled.
1856 set startup-with-shell
1857 show startup-with-shell
1858 Specifies whether Unix child processes are started via a shell or
1863 Use the target memory cache for accesses to the code segment. This
1864 improves performance of remote debugging (particularly disassembly).
1866 * You can now use a literal value 'unlimited' for options that
1867 interpret 0 or -1 as meaning "unlimited". E.g., "set
1868 trace-buffer-size unlimited" is now an alias for "set
1869 trace-buffer-size -1" and "set height unlimited" is now an alias for
1872 * The "set debug symtab-create" debugging option of GDB has been changed to
1873 accept a verbosity level. 0 means "off", 1 provides basic debugging
1874 output, and values of 2 or greater provides more verbose output.
1876 * New command-line options
1878 Display the details of GDB configure-time options.
1880 * The command 'tsave' can now support new option '-ctf' to save trace
1881 buffer in Common Trace Format.
1883 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1886 * GDB now implements the the C++ 'typeid' operator.
1888 * The new convenience variable $_exception holds the exception being
1889 thrown or caught at an exception-related catchpoint.
1891 * The exception-related catchpoints, like "catch throw", now accept a
1892 regular expression which can be used to filter exceptions by type.
1894 * The new convenience variable $_exitsignal is automatically set to
1895 the terminating signal number when the program being debugged dies
1896 due to an uncaught signal.
1900 ** All MI commands now accept an optional "--language" option.
1901 Support for this feature can be verified by using the "-list-features"
1902 command, which should contain "language-option".
1904 ** The new command -info-gdb-mi-command allows the user to determine
1905 whether a GDB/MI command is supported or not.
1907 ** The "^error" result record returned when trying to execute an undefined
1908 GDB/MI command now provides a variable named "code" whose content is the
1909 "undefined-command" error code. Support for this feature can be verified
1910 by using the "-list-features" command, which should contain
1911 "undefined-command-error-code".
1913 ** The -trace-save MI command can optionally save trace buffer in Common
1916 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1918 ** The command -data-list-register-values now accepts an optional
1919 "--skip-unavailable" option. When used, only the available registers
1922 ** The new command -trace-frame-collected dumps collected variables,
1923 computed expressions, tvars, memory and registers in a traceframe.
1925 ** The commands -stack-list-locals, -stack-list-arguments and
1926 -stack-list-variables now accept an option "--skip-unavailable".
1927 When used, only the available locals or arguments are displayed.
1929 ** The -exec-run command now accepts an optional "--start" option.
1930 When used, the command follows the same semantics as the "start"
1931 command, stopping the program's execution at the start of its
1932 main subprogram. Support for this feature can be verified using
1933 the "-list-features" command, which should contain
1934 "exec-run-start-option".
1936 ** The new commands -catch-assert and -catch-exceptions insert
1937 catchpoints stopping the program when Ada exceptions are raised.
1939 ** The new command -info-ada-exceptions provides the equivalent of
1940 the new "info exceptions" command.
1942 * New system-wide configuration scripts
1943 A GDB installation now provides scripts suitable for use as system-wide
1944 configuration scripts for the following systems:
1948 * GDB now supports target-assigned range stepping with remote targets.
1949 This improves the performance of stepping source lines by reducing
1950 the number of control packets from/to GDB. See "New remote packets"
1953 * GDB now understands the element 'tvar' in the XML traceframe info.
1954 It has the id of the collected trace state variables.
1956 * On S/390 targets that provide the transactional-execution feature,
1957 the program interruption transaction diagnostic block (TDB) is now
1958 represented as a number of additional "registers" in GDB.
1960 * New remote packets
1964 The vCont packet supports a new 'r' action, that tells the remote
1965 stub to step through an address range itself, without GDB
1966 involvemement at each single-step.
1968 qXfer:libraries-svr4:read's annex
1969 The previously unused annex of the qXfer:libraries-svr4:read packet
1970 is now used to support passing an argument list. The remote stub
1971 reports support for this argument list to GDB's qSupported query.
1972 The defined arguments are "start" and "prev", used to reduce work
1973 necessary for library list updating, resulting in significant
1976 * New features in the GDB remote stub, GDBserver
1978 ** GDBserver now supports target-assisted range stepping. Currently
1979 enabled on x86/x86_64 GNU/Linux targets.
1981 ** GDBserver now adds element 'tvar' in the XML in the reply to
1982 'qXfer:traceframe-info:read'. It has the id of the collected
1983 trace state variables.
1985 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1988 * New 'z' formatter for printing and examining memory, this displays the
1989 value as hexadecimal zero padded on the left to the size of the type.
1991 * GDB can now use Windows x64 unwinding data.
1993 * The "set remotebaud" command has been replaced by "set serial baud".
1994 Similarly, "show remotebaud" has been replaced by "show serial baud".
1995 The "set remotebaud" and "show remotebaud" commands are still available
1996 to provide backward compatibility with older versions of GDB.
1998 *** Changes in GDB 7.6
2000 * Target record has been renamed to record-full.
2001 Record/replay is now enabled with the "record full" command.
2002 This also affects settings that are associated with full record/replay
2003 that have been moved from "set/show record" to "set/show record full":
2005 set|show record full insn-number-max
2006 set|show record full stop-at-limit
2007 set|show record full memory-query
2009 * A new record target "record-btrace" has been added. The new target
2010 uses hardware support to record the control-flow of a process. It
2011 does not support replaying the execution, but it implements the
2012 below new commands for investigating the recorded execution log.
2013 This new recording method can be enabled using:
2017 The "record-btrace" target is only available on Intel Atom processors
2018 and requires a Linux kernel 2.6.32 or later.
2020 * Two new commands have been added for record/replay to give information
2021 about the recorded execution without having to replay the execution.
2022 The commands are only supported by "record btrace".
2024 record instruction-history prints the execution history at
2025 instruction granularity
2027 record function-call-history prints the execution history at
2028 function granularity
2030 * New native configurations
2032 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2033 FreeBSD/powerpc powerpc*-*-freebsd
2034 x86_64/Cygwin x86_64-*-cygwin*
2035 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2039 ARM AArch64 aarch64*-*-elf
2040 ARM AArch64 GNU/Linux aarch64*-*-linux
2041 Lynx 178 PowerPC powerpc-*-lynx*178
2042 x86_64/Cygwin x86_64-*-cygwin*
2043 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2045 * If the configured location of system.gdbinit file (as given by the
2046 --with-system-gdbinit option at configure time) is in the
2047 data-directory (as specified by --with-gdb-datadir at configure
2048 time) or in one of its subdirectories, then GDB will look for the
2049 system-wide init file in the directory specified by the
2050 --data-directory command-line option.
2052 * New command line options:
2054 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2055 other initialization files, unlike -nx which disables all of them.
2057 * Removed command line options
2059 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2062 * The 'ptype' and 'whatis' commands now accept an argument to control
2065 * 'info proc' now works on some core files.
2069 ** Vectors can be created with gdb.Type.vector.
2071 ** Python's atexit.register now works in GDB.
2073 ** Types can be pretty-printed via a Python API.
2075 ** Python 3 is now supported (in addition to Python 2.4 or later)
2077 ** New class gdb.Architecture exposes GDB's internal representation
2078 of architecture in the Python API.
2080 ** New method Frame.architecture returns the gdb.Architecture object
2081 corresponding to the frame's architecture.
2083 * New Python-based convenience functions:
2085 ** $_memeq(buf1, buf2, length)
2086 ** $_streq(str1, str2)
2088 ** $_regex(str, regex)
2090 * The 'cd' command now defaults to using '~' (the home directory) if not
2093 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2094 default for GCC since November 2000.
2096 * The command 'forward-search' can now be abbreviated as 'fo'.
2098 * The command 'info tracepoints' can now display 'installed on target'
2099 or 'not installed on target' for each non-pending location of tracepoint.
2101 * New configure options
2103 --enable-libmcheck/--disable-libmcheck
2104 By default, development versions are built with -lmcheck on hosts
2105 that support it, in order to help track memory corruption issues.
2106 Release versions, on the other hand, are built without -lmcheck
2107 by default. The --enable-libmcheck/--disable-libmcheck configure
2108 options allow the user to override that default.
2109 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2110 This configure option allows the user to build GDB with
2111 libbabeltrace using which GDB can read Common Trace Format data.
2113 * New commands (for set/show, see "New options" below)
2116 Catch signals. This is similar to "handle", but allows commands and
2117 conditions to be attached.
2120 List the BFDs known to GDB.
2122 python-interactive [command]
2124 Start a Python interactive prompt, or evaluate the optional command
2125 and print the result of expressions.
2128 "py" is a new alias for "python".
2130 enable type-printer [name]...
2131 disable type-printer [name]...
2132 Enable or disable type printers.
2136 ** For the Renesas Super-H architecture, the "regs" command has been removed
2137 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2142 set print type methods (on|off)
2143 show print type methods
2144 Control whether method declarations are displayed by "ptype".
2145 The default is to show them.
2147 set print type typedefs (on|off)
2148 show print type typedefs
2149 Control whether typedef definitions are displayed by "ptype".
2150 The default is to show them.
2152 set filename-display basename|relative|absolute
2153 show filename-display
2154 Control the way in which filenames is displayed.
2155 The default is "relative", which preserves previous behavior.
2157 set trace-buffer-size
2158 show trace-buffer-size
2159 Request target to change the size of trace buffer.
2161 set remote trace-buffer-size-packet auto|on|off
2162 show remote trace-buffer-size-packet
2163 Control the use of the remote protocol `QTBuffer:size' packet.
2167 Control display of debugging messages related to ARM AArch64.
2170 set debug coff-pe-read
2171 show debug coff-pe-read
2172 Control display of debugging messages related to reading of COFF/PE
2177 Control display of debugging messages related to Mach-O symbols
2180 set debug notification
2181 show debug notification
2182 Control display of debugging info for async remote notification.
2186 ** Command parameter changes are now notified using new async record
2187 "=cmd-param-changed".
2188 ** Trace frame changes caused by command "tfind" are now notified using
2189 new async record "=traceframe-changed".
2190 ** The creation, deletion and modification of trace state variables
2191 are now notified using new async records "=tsv-created",
2192 "=tsv-deleted" and "=tsv-modified".
2193 ** The start and stop of process record are now notified using new
2194 async record "=record-started" and "=record-stopped".
2195 ** Memory changes are now notified using new async record
2197 ** The data-disassemble command response will include a "fullname" field
2198 containing the absolute file name when source has been requested.
2199 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2200 command, to allow pattern filling of memory areas.
2201 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2202 library load/unload events.
2203 ** The response to breakpoint commands and breakpoint async records
2204 includes an "installed" field containing a boolean state about each
2205 non-pending tracepoint location is whether installed on target or not.
2206 ** Output of the "-trace-status" command includes a "trace-file" field
2207 containing the name of the trace file being examined. This field is
2208 optional, and only present when examining a trace file.
2209 ** The "fullname" field is now always present along with the "file" field,
2210 even if the file cannot be found by GDB.
2212 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2213 You must have the LZMA library available when configuring GDB for this
2214 feature to be enabled. For more information, see:
2215 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2217 * New remote packets
2220 Set the size of trace buffer. The remote stub reports support for this
2221 packet to gdb's qSupported query.
2224 Enable Branch Trace Store (BTS)-based branch tracing for the current
2225 thread. The remote stub reports support for this packet to gdb's
2229 Disable branch tracing for the current thread. The remote stub reports
2230 support for this packet to gdb's qSupported query.
2233 Read the traced branches for the current thread. The remote stub
2234 reports support for this packet to gdb's qSupported query.
2236 *** Changes in GDB 7.5
2238 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2239 for more x32 ABI info.
2241 * GDB now supports access to MIPS DSP registers on Linux targets.
2243 * GDB now supports debugging microMIPS binaries.
2245 * The "info os" command on GNU/Linux can now display information on
2246 several new classes of objects managed by the operating system:
2247 "info os procgroups" lists process groups
2248 "info os files" lists file descriptors
2249 "info os sockets" lists internet-domain sockets
2250 "info os shm" lists shared-memory regions
2251 "info os semaphores" lists semaphores
2252 "info os msg" lists message queues
2253 "info os modules" lists loaded kernel modules
2255 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2256 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2257 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2258 options and inspect the probe arguments using the new $_probe_arg family
2259 of convenience variables. You can obtain more information about SystemTap
2260 in <http://sourceware.org/systemtap/>.
2262 * GDB now supports reversible debugging on ARM, it allows you to
2263 debug basic ARM and THUMB instructions, and provides
2264 record/replay support.
2266 * The option "symbol-reloading" has been deleted as it is no longer used.
2270 ** GDB commands implemented in Python can now be put in command class
2273 ** The "maint set python print-stack on|off" is now deleted.
2275 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2276 apply "flag enum"-style pretty-printing to any enum.
2278 ** gdb.lookup_symbol can now work when there is no current frame.
2280 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2281 the source at which the symbol was defined.
2283 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2284 method 'value'. The former indicates whether the symbol needs a
2285 frame in order to compute its value, and the latter computes the
2288 ** A new method 'referenced_value' on gdb.Value objects which can
2289 dereference pointer as well as C++ reference values.
2291 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2292 which return the global and static blocks (as gdb.Block objects),
2293 of the underlying symbol table, respectively.
2295 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2296 object associated with a PC value.
2298 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2299 of the address range occupied by code for the current source line.
2301 * Go language support.
2302 GDB now supports debugging programs written in the Go programming
2305 * GDBserver now supports stdio connections.
2306 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2308 * The binary "gdbtui" can no longer be built or installed.
2309 Use "gdb -tui" instead.
2311 * GDB will now print "flag" enums specially. A flag enum is one where
2312 all the enumerator values have no bits in common when pairwise
2313 "and"ed. When printing a value whose type is a flag enum, GDB will
2314 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2315 (gdb) print (enum E) 3
2318 * The filename part of a linespec will now match trailing components
2319 of a source file name. For example, "break gcc/expr.c:1000" will
2320 now set a breakpoint in build/gcc/expr.c, but not
2321 build/libcpp/expr.c.
2323 * The "info proc" and "generate-core-file" commands will now also
2324 work on remote targets connected to GDBserver on Linux.
2326 * The command "info catch" has been removed. It has been disabled
2327 since December 2007.
2329 * The "catch exception" and "catch assert" commands now accept
2330 a condition at the end of the command, much like the "break"
2331 command does. For instance:
2333 (gdb) catch exception Constraint_Error if Barrier = True
2335 Previously, it was possible to add a condition to such catchpoints,
2336 but it had to be done as a second step, after the catchpoint had been
2337 created, using the "condition" command.
2339 * The "info static-tracepoint-marker" command will now also work on
2340 native Linux targets with in-process agent.
2342 * GDB can now set breakpoints on inlined functions.
2344 * The .gdb_index section has been updated to include symbols for
2345 inlined functions. GDB will ignore older .gdb_index sections by
2346 default, which could cause symbol files to be loaded more slowly
2347 until their .gdb_index sections can be recreated. The new command
2348 "set use-deprecated-index-sections on" will cause GDB to use any older
2349 .gdb_index sections it finds. This will restore performance, but the
2350 ability to set breakpoints on inlined functions will be lost in symbol
2351 files with older .gdb_index sections.
2353 The .gdb_index section has also been updated to record more information
2354 about each symbol. This speeds up the "info variables", "info functions"
2355 and "info types" commands when used with programs having the .gdb_index
2356 section, as well as speeding up debugging with shared libraries using
2357 the .gdb_index section.
2359 * Ada support for GDB/MI Variable Objects has been added.
2361 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2366 ** New command -info-os is the MI equivalent of "info os".
2368 ** Output logs ("set logging" and related) now include MI output.
2372 ** "set use-deprecated-index-sections on|off"
2373 "show use-deprecated-index-sections on|off"
2374 Controls the use of deprecated .gdb_index sections.
2376 ** "catch load" and "catch unload" can be used to stop when a shared
2377 library is loaded or unloaded, respectively.
2379 ** "enable count" can be used to auto-disable a breakpoint after
2382 ** "info vtbl" can be used to show the virtual method tables for
2383 C++ and Java objects.
2385 ** "explore" and its sub commands "explore value" and "explore type"
2386 can be used to recursively explore values and types of
2387 expressions. These commands are available only if GDB is
2388 configured with '--with-python'.
2390 ** "info auto-load" shows status of all kinds of auto-loaded files,
2391 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2392 sequences of commands files, "info auto-load python-scripts"
2393 shows status of auto-loading Python script files,
2394 "info auto-load local-gdbinit" shows status of loading init file
2395 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2396 status of inferior specific thread debugging shared library loading.
2398 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2399 and "show auto-load-scripts" commands have been deprecated, use their
2400 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2401 and "show auto-load python-scripts" counterparts instead.
2403 ** "dprintf location,format,args..." creates a dynamic printf, which
2404 is basically a breakpoint that does a printf and immediately
2405 resumes your program's execution, so it is like a printf that you
2406 can insert dynamically at runtime instead of at compiletime.
2408 ** "set print symbol"
2410 Controls whether GDB attempts to display the symbol, if any,
2411 corresponding to addresses it prints. This defaults to "on", but
2412 you can set it to "off" to restore GDB's previous behavior.
2414 * Deprecated commands
2416 ** For the Renesas Super-H architecture, the "regs" command has been
2417 deprecated, and "info all-registers" should be used instead.
2421 Renesas RL78 rl78-*-elf
2422 HP OpenVMS ia64 ia64-hp-openvms*
2424 * GDBserver supports evaluation of breakpoint conditions. When
2425 support is advertised by GDBserver, GDB may be told to send the
2426 breakpoint conditions in bytecode form to GDBserver. GDBserver
2427 will only report the breakpoint trigger to GDB when its condition
2432 set mips compression
2433 show mips compression
2434 Select the compressed ISA encoding used in functions that have no symbol
2435 information available. The encoding can be set to either of:
2438 and is updated automatically from ELF file flags if available.
2440 set breakpoint condition-evaluation
2441 show breakpoint condition-evaluation
2442 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2443 GDBserver ("target"). Default option "auto" chooses the most efficient
2445 This option can improve debugger efficiency depending on the speed of the
2449 Disable auto-loading globally.
2452 Show auto-loading setting of all kinds of auto-loaded files.
2454 set auto-load gdb-scripts on|off
2455 show auto-load gdb-scripts
2456 Control auto-loading of GDB canned sequences of commands files.
2458 set auto-load python-scripts on|off
2459 show auto-load python-scripts
2460 Control auto-loading of Python script files.
2462 set auto-load local-gdbinit on|off
2463 show auto-load local-gdbinit
2464 Control loading of init file (.gdbinit) from current directory.
2466 set auto-load libthread-db on|off
2467 show auto-load libthread-db
2468 Control auto-loading of inferior specific thread debugging shared library.
2470 set auto-load scripts-directory <dir1>[:<dir2>...]
2471 show auto-load scripts-directory
2472 Set a list of directories from which to load auto-loaded scripts.
2473 Automatically loaded Python scripts and GDB scripts are located in one
2474 of the directories listed by this option.
2475 The delimiter (':' above) may differ according to the host platform.
2477 set auto-load safe-path <dir1>[:<dir2>...]
2478 show auto-load safe-path
2479 Set a list of directories from which it is safe to auto-load files.
2480 The delimiter (':' above) may differ according to the host platform.
2482 set debug auto-load on|off
2483 show debug auto-load
2484 Control display of debugging info for auto-loading the files above.
2486 set dprintf-style gdb|call|agent
2488 Control the way in which a dynamic printf is performed; "gdb"
2489 requests a GDB printf command, while "call" causes dprintf to call a
2490 function in the inferior. "agent" requests that the target agent
2491 (such as GDBserver) do the printing.
2493 set dprintf-function <expr>
2494 show dprintf-function
2495 set dprintf-channel <expr>
2496 show dprintf-channel
2497 Set the function and optional first argument to the call when using
2498 the "call" style of dynamic printf.
2500 set disconnected-dprintf on|off
2501 show disconnected-dprintf
2502 Control whether agent-style dynamic printfs continue to be in effect
2503 after GDB disconnects.
2505 * New configure options
2507 --with-auto-load-dir
2508 Configure default value for the 'set auto-load scripts-directory'
2509 setting above. It defaults to '$debugdir:$datadir/auto-load',
2510 $debugdir representing global debugging info directories (available
2511 via 'show debug-file-directory') and $datadir representing GDB's data
2512 directory (available via 'show data-directory').
2514 --with-auto-load-safe-path
2515 Configure default value for the 'set auto-load safe-path' setting
2516 above. It defaults to the --with-auto-load-dir setting.
2518 --without-auto-load-safe-path
2519 Set 'set auto-load safe-path' to '/', effectively disabling this
2522 * New remote packets
2524 z0/z1 conditional breakpoints extension
2526 The z0/z1 breakpoint insertion packets have been extended to carry
2527 a list of conditional expressions over to the remote stub depending on the
2528 condition evaluation mode. The use of this extension can be controlled
2529 via the "set remote conditional-breakpoints-packet" command.
2533 Specify the signals which the remote stub may pass to the debugged
2534 program without GDB involvement.
2536 * New command line options
2538 --init-command=FILE, -ix Like --command, -x but execute it
2539 before loading inferior.
2540 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2541 execute it before loading inferior.
2543 *** Changes in GDB 7.4
2545 * GDB now handles ambiguous linespecs more consistently; the existing
2546 FILE:LINE support has been expanded to other types of linespecs. A
2547 breakpoint will now be set on all matching locations in all
2548 inferiors, and locations will be added or removed according to
2551 * GDB now allows you to skip uninteresting functions and files when
2552 stepping with the "skip function" and "skip file" commands.
2554 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2555 and "show remote hardware-watchpoint-length-limit". These allows to
2556 set or show the maximum length limit (in bytes) of a remote
2557 target hardware watchpoint.
2559 This allows e.g. to use "unlimited" hardware watchpoints with the
2560 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2561 watchpoints are slower than real hardware watchpoints but are
2562 significantly faster than gdb software watchpoints.
2566 ** The register_pretty_printer function in module gdb.printing now takes
2567 an optional `replace' argument. If True, the new printer replaces any
2570 ** The "maint set python print-stack on|off" command has been
2571 deprecated and will be deleted in GDB 7.5.
2572 A new command: "set python print-stack none|full|message" has
2573 replaced it. Additionally, the default for "print-stack" is
2574 now "message", which just prints the error message without
2577 ** A prompt substitution hook (prompt_hook) is now available to the
2580 ** A new Python module, gdb.prompt has been added to the GDB Python
2581 modules library. This module provides functionality for
2582 escape sequences in prompts (used by set/show
2583 extended-prompt). These escape sequences are replaced by their
2584 corresponding value.
2586 ** Python commands and convenience-functions located in
2587 'data-directory'/python/gdb/command and
2588 'data-directory'/python/gdb/function are now automatically loaded
2591 ** Blocks now provide four new attributes. global_block and
2592 static_block will return the global and static blocks
2593 respectively. is_static and is_global are boolean attributes
2594 that indicate if the block is one of those two types.
2596 ** Symbols now provide the "type" attribute, the type of the symbol.
2598 ** The "gdb.breakpoint" function has been deprecated in favor of
2601 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2602 of a function. This class is based on the "finish" command
2603 available in the CLI.
2605 ** Type objects for struct and union types now allow access to
2606 the fields using standard Python dictionary (mapping) methods.
2607 For example, "some_type['myfield']" now works, as does
2608 "some_type.items()".
2610 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2613 ** A new function, "deep_items" has been added to the gdb.types
2614 module in the GDB Python modules library. This function returns
2615 an iterator over the fields of a struct or union type. Unlike
2616 the standard Python "iteritems" method, it will recursively traverse
2617 any anonymous fields.
2621 ** "*stopped" events can report several new "reason"s, such as
2624 ** Breakpoint changes are now notified using new async records, like
2625 "=breakpoint-modified".
2627 ** New command -ada-task-info.
2629 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2630 $sdir specifies the default system locations of shared libraries.
2631 $pdir specifies the directory where the libpthread used by the application
2634 GDB no longer looks in $sdir and $pdir after it has searched the directories
2635 mentioned in libthread-db-search-path. If you want to search those
2636 directories, they must be specified in libthread-db-search-path.
2637 The default value of libthread-db-search-path on GNU/Linux and Solaris
2638 systems is now "$sdir:$pdir".
2640 $pdir is not supported by gdbserver, it is currently ignored.
2641 $sdir is supported by gdbserver.
2643 * New configure option --with-iconv-bin.
2644 When using the internationalization support like the one in the GNU C
2645 library, GDB will invoke the "iconv" program to get a list of supported
2646 character sets. If this program lives in a non-standard location, one can
2647 use this option to specify where to find it.
2649 * When natively debugging programs on PowerPC BookE processors running
2650 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2651 watchpoints, which specify a mask in addition to an address to watch.
2652 The mask specifies that some bits of an address (the bits which are
2653 reset in the mask) should be ignored when matching the address accessed
2654 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2655 section in the user manual for more details.
2657 * The new option --once causes GDBserver to stop listening for connections once
2658 the first connection is made. The listening port used by GDBserver will
2659 become available after that.
2661 * New commands "info macros" and "alias" have been added.
2663 * New function parameters suffix @entry specifies value of function parameter
2664 at the time the function got called. Entry values are available only since
2670 "!" is now an alias of the "shell" command.
2671 Note that no space is needed between "!" and SHELL COMMAND.
2675 watch EXPRESSION mask MASK_VALUE
2676 The watch command now supports the mask argument which allows creation
2677 of masked watchpoints, if the current architecture supports this feature.
2679 info auto-load-scripts [REGEXP]
2680 This command was formerly named "maintenance print section-scripts".
2681 It is now generally useful and is no longer a maintenance-only command.
2683 info macro [-all] [--] MACRO
2684 The info macro command has new options `-all' and `--'. The first for
2685 printing all definitions of a macro. The second for explicitly specifying
2686 the end of arguments and the beginning of the macro name in case the macro
2687 name starts with a hyphen.
2689 collect[/s] EXPRESSIONS
2690 The tracepoint collect command now takes an optional modifier "/s"
2691 that directs it to dereference pointer-to-character types and
2692 collect the bytes of memory up to a zero byte. The behavior is
2693 similar to what you see when you use the regular print command on a
2694 string. An optional integer following the "/s" sets a bound on the
2695 number of bytes that will be collected.
2698 The trace start command now interprets any supplied arguments as a
2699 note to be recorded with the trace run, with an effect similar to
2700 setting the variable trace-notes.
2703 The trace stop command now interprets any arguments as a note to be
2704 mentioned along with the tstatus report that the trace was stopped
2705 with a command. The effect is similar to setting the variable
2708 * Tracepoints can now be enabled and disabled at any time after a trace
2709 experiment has been started using the standard "enable" and "disable"
2710 commands. It is now possible to start a trace experiment with no enabled
2711 tracepoints; GDB will display a warning, but will allow the experiment to
2712 begin, assuming that tracepoints will be enabled as needed while the trace
2715 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2716 locations with 4-byte instructions, when they were previously
2717 limited to locations with instructions of 5 bytes or longer.
2721 set debug dwarf2-read
2722 show debug dwarf2-read
2723 Turns on or off display of debugging messages related to reading
2724 DWARF debug info. The default is off.
2726 set debug symtab-create
2727 show debug symtab-create
2728 Turns on or off display of debugging messages related to symbol table
2729 creation. The default is off.
2732 show extended-prompt
2733 Set the GDB prompt, and allow escape sequences to be inserted to
2734 display miscellaneous information (see 'help set extended-prompt'
2735 for the list of sequences). This prompt (and any information
2736 accessed through the escape sequences) is updated every time the
2737 prompt is displayed.
2739 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2740 show print entry-values
2741 Set printing of frame argument values at function entry. In some cases
2742 GDB can determine the value of function argument which was passed by the
2743 function caller, even if the value was modified inside the called function.
2745 set debug entry-values
2746 show debug entry-values
2747 Control display of debugging info for determining frame argument values at
2748 function entry and virtual tail call frames.
2750 set basenames-may-differ
2751 show basenames-may-differ
2752 Set whether a source file may have multiple base names.
2753 (A "base name" is the name of a file with the directory part removed.
2754 Example: The base name of "/home/user/hello.c" is "hello.c".)
2755 If set, GDB will canonicalize file names (e.g., expand symlinks)
2756 before comparing them. Canonicalization is an expensive operation,
2757 but it allows the same file be known by more than one base name.
2758 If not set (the default), all source files are assumed to have just
2759 one base name, and gdb will do file name comparisons more efficiently.
2765 Set a user name and notes for the current and any future trace runs.
2766 This is useful for long-running and/or disconnected traces, to
2767 inform others (or yourself) as to who is running the trace, supply
2768 contact information, or otherwise explain what is going on.
2770 set trace-stop-notes
2771 show trace-stop-notes
2772 Set a note attached to the trace run, that is displayed when the
2773 trace has been stopped by a tstop command. This is useful for
2774 instance as an explanation, if you are stopping a trace run that was
2775 started by someone else.
2777 * New remote packets
2781 Dynamically enable a tracepoint in a started trace experiment.
2785 Dynamically disable a tracepoint in a started trace experiment.
2789 Set the user and notes of the trace run.
2793 Query the current status of a tracepoint.
2797 Query the minimum length of instruction at which a fast tracepoint may
2800 * Dcache size (number of lines) and line-size are now runtime-configurable
2801 via "set dcache line" and "set dcache line-size" commands.
2805 Texas Instruments TMS320C6x tic6x-*-*
2809 Renesas RL78 rl78-*-elf
2811 *** Changes in GDB 7.3.1
2813 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2815 *** Changes in GDB 7.3
2817 * GDB has a new command: "thread find [REGEXP]".
2818 It finds the thread id whose name, target id, or thread extra info
2819 matches the given regular expression.
2821 * The "catch syscall" command now works on mips*-linux* targets.
2823 * The -data-disassemble MI command now supports modes 2 and 3 for
2824 dumping the instruction opcodes.
2826 * New command line options
2828 -data-directory DIR Specify DIR as the "data-directory".
2829 This is mostly for testing purposes.
2831 * The "maint set python auto-load on|off" command has been renamed to
2832 "set auto-load-scripts on|off".
2834 * GDB has a new command: "set directories".
2835 It is like the "dir" command except that it replaces the
2836 source path list instead of augmenting it.
2838 * GDB now understands thread names.
2840 On GNU/Linux, "info threads" will display the thread name as set by
2841 prctl or pthread_setname_np.
2843 There is also a new command, "thread name", which can be used to
2844 assign a name internally for GDB to display.
2847 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2848 has been integrated into GDB.
2852 ** The function gdb.Write now accepts an optional keyword 'stream'.
2853 This keyword, when provided, will direct the output to either
2854 stdout, stderr, or GDB's logging output.
2856 ** Parameters can now be be sub-classed in Python, and in particular
2857 you may implement the get_set_doc and get_show_doc functions.
2858 This improves how Parameter set/show documentation is processed
2859 and allows for more dynamic content.
2861 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2862 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2863 have an is_valid method.
2865 ** Breakpoints can now be sub-classed in Python, and in particular
2866 you may implement a 'stop' function that is executed each time
2867 the inferior reaches that breakpoint.
2869 ** New function gdb.lookup_global_symbol looks up a global symbol.
2871 ** GDB values in Python are now callable if the value represents a
2872 function. For example, if 'some_value' represents a function that
2873 takes two integer parameters and returns a value, you can call
2874 that function like so:
2876 result = some_value (10,20)
2878 ** Module gdb.types has been added.
2879 It contains a collection of utilities for working with gdb.Types objects:
2880 get_basic_type, has_field, make_enum_dict.
2882 ** Module gdb.printing has been added.
2883 It contains utilities for writing and registering pretty-printers.
2884 New classes: PrettyPrinter, SubPrettyPrinter,
2885 RegexpCollectionPrettyPrinter.
2886 New function: register_pretty_printer.
2888 ** New commands "info pretty-printers", "enable pretty-printer" and
2889 "disable pretty-printer" have been added.
2891 ** gdb.parameter("directories") is now available.
2893 ** New function gdb.newest_frame returns the newest frame in the
2896 ** The gdb.InferiorThread class has a new "name" attribute. This
2897 holds the thread's name.
2899 ** Python Support for Inferior events.
2900 Python scripts can add observers to be notified of events
2901 occurring in the process being debugged.
2902 The following events are currently supported:
2903 - gdb.events.cont Continue event.
2904 - gdb.events.exited Inferior exited event.
2905 - gdb.events.stop Signal received, and Breakpoint hit events.
2909 ** GDB now puts template parameters in scope when debugging in an
2910 instantiation. For example, if you have:
2912 template<int X> int func (void) { return X; }
2914 then if you step into func<5>, "print X" will show "5". This
2915 feature requires proper debuginfo support from the compiler; it
2916 was added to GCC 4.5.
2918 ** The motion commands "next", "finish", "until", and "advance" now
2919 work better when exceptions are thrown. In particular, GDB will
2920 no longer lose control of the inferior; instead, the GDB will
2921 stop the inferior at the point at which the exception is caught.
2922 This functionality requires a change in the exception handling
2923 code that was introduced in GCC 4.5.
2925 * GDB now follows GCC's rules on accessing volatile objects when
2926 reading or writing target state during expression evaluation.
2927 One notable difference to prior behavior is that "print x = 0"
2928 no longer generates a read of x; the value of the assignment is
2929 now always taken directly from the value being assigned.
2931 * GDB now has some support for using labels in the program's source in
2932 linespecs. For instance, you can use "advance label" to continue
2933 execution to a label.
2935 * GDB now has support for reading and writing a new .gdb_index
2936 section. This section holds a fast index of DWARF debugging
2937 information and can be used to greatly speed up GDB startup and
2938 operation. See the documentation for `save gdb-index' for details.
2940 * The "watch" command now accepts an optional "-location" argument.
2941 When used, this causes GDB to watch the memory referred to by the
2942 expression. Such a watchpoint is never deleted due to it going out
2945 * GDB now supports thread debugging of core dumps on GNU/Linux.
2947 GDB now activates thread debugging using the libthread_db library
2948 when debugging GNU/Linux core dumps, similarly to when debugging
2949 live processes. As a result, when debugging a core dump file, GDB
2950 is now able to display pthread_t ids of threads. For example, "info
2951 threads" shows the same output as when debugging the process when it
2952 was live. In earlier releases, you'd see something like this:
2955 * 1 LWP 6780 main () at main.c:10
2957 While now you see this:
2960 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2962 It is also now possible to inspect TLS variables when debugging core
2965 When debugging a core dump generated on a machine other than the one
2966 used to run GDB, you may need to point GDB at the correct
2967 libthread_db library with the "set libthread-db-search-path"
2968 command. See the user manual for more details on this command.
2970 * When natively debugging programs on PowerPC BookE processors running
2971 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2972 which stop execution of the inferior whenever it executes an instruction
2973 at any address within the specified range. See the "PowerPC Embedded"
2974 section in the user manual for more details.
2976 * New features in the GDB remote stub, GDBserver
2978 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2979 and i686 LynxOS (version 5.x).
2981 ** GDBserver is now supported on Blackfin Linux.
2983 * New native configurations
2985 ia64 HP-UX ia64-*-hpux*
2989 Analog Devices, Inc. Blackfin Processor bfin-*
2991 * Ada task switching is now supported on sparc-elf targets when
2992 debugging a program using the Ravenscar Profile. For more information,
2993 see the "Tasking Support when using the Ravenscar Profile" section
2994 in the GDB user manual.
2996 * Guile support was removed.
2998 * New features in the GNU simulator
3000 ** The --map-info flag lists all known core mappings.
3002 ** CFI flashes may be simulated via the "cfi" device.
3004 *** Changes in GDB 7.2
3006 * Shared library support for remote targets by default
3008 When GDB is configured for a generic, non-OS specific target, like
3009 for example, --target=arm-eabi or one of the many *-*-elf targets,
3010 GDB now queries remote stubs for loaded shared libraries using the
3011 `qXfer:libraries:read' packet. Previously, shared library support
3012 was always disabled for such configurations.
3016 ** Argument Dependent Lookup (ADL)
3018 In C++ ADL lookup directs function search to the namespaces of its
3019 arguments even if the namespace has not been imported.
3029 Here the compiler will search for `foo' in the namespace of 'b'
3030 and find A::foo. GDB now supports this. This construct is commonly
3031 used in the Standard Template Library for operators.
3033 ** Improved User Defined Operator Support
3035 In addition to member operators, GDB now supports lookup of operators
3036 defined in a namespace and imported with a `using' directive, operators
3037 defined in the global scope, operators imported implicitly from an
3038 anonymous namespace, and the ADL operators mentioned in the previous
3040 GDB now also supports proper overload resolution for all the previously
3041 mentioned flavors of operators.
3043 ** static const class members
3045 Printing of static const class members that are initialized in the
3046 class definition has been fixed.
3048 * Windows Thread Information Block access.
3050 On Windows targets, GDB now supports displaying the Windows Thread
3051 Information Block (TIB) structure. This structure is visible either
3052 by using the new command `info w32 thread-information-block' or, by
3053 dereferencing the new convenience variable named `$_tlb', a
3054 thread-specific pointer to the TIB. This feature is also supported
3055 when remote debugging using GDBserver.
3057 * Static tracepoints
3059 Static tracepoints are calls in the user program into a tracing
3060 library. One such library is a port of the LTTng kernel tracer to
3061 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3062 When debugging with GDBserver, GDB now supports combining the GDB
3063 tracepoint machinery with such libraries. For example: the user can
3064 use GDB to probe a static tracepoint marker (a call from the user
3065 program into the tracing library) with the new "strace" command (see
3066 "New commands" below). This creates a "static tracepoint" in the
3067 breakpoint list, that can be manipulated with the same feature set
3068 as fast and regular tracepoints. E.g., collect registers, local and
3069 global variables, collect trace state variables, and define
3070 tracepoint conditions. In addition, the user can collect extra
3071 static tracepoint marker specific data, by collecting the new
3072 $_sdata internal variable. When analyzing the trace buffer, you can
3073 inspect $_sdata like any other variable available to GDB. For more
3074 information, see the "Tracepoints" chapter in GDB user manual. New
3075 remote packets have been defined to support static tracepoints, see
3076 the "New remote packets" section below.
3078 * Better reconstruction of tracepoints after disconnected tracing
3080 GDB will attempt to download the original source form of tracepoint
3081 definitions when starting a trace run, and then will upload these
3082 upon reconnection to the target, resulting in a more accurate
3083 reconstruction of the tracepoints that are in use on the target.
3087 You can now exercise direct control over the ways that GDB can
3088 affect your program. For instance, you can disallow the setting of
3089 breakpoints, so that the program can run continuously (assuming
3090 non-stop mode). In addition, the "observer" variable is available
3091 to switch all of the different controls; in observer mode, GDB
3092 cannot affect the target's behavior at all, which is useful for
3093 tasks like diagnosing live systems in the field.
3095 * The new convenience variable $_thread holds the number of the
3098 * New remote packets
3102 Return the address of the Windows Thread Information Block of a given thread.
3106 In response to several of the tracepoint packets, the target may now
3107 also respond with a number of intermediate `qRelocInsn' request
3108 packets before the final result packet, to have GDB handle
3109 relocating an instruction to execute at a different address. This
3110 is particularly useful for stubs that support fast tracepoints. GDB
3111 reports support for this feature in the qSupported packet.
3115 List static tracepoint markers in the target program.
3119 List static tracepoint markers at a given address in the target
3122 qXfer:statictrace:read
3124 Read the static trace data collected (by a `collect $_sdata'
3125 tracepoint action). The remote stub reports support for this packet
3126 to gdb's qSupported query.
3130 Send the current settings of GDB's permission flags.
3134 Send part of the source (textual) form of a tracepoint definition,
3135 which includes location, conditional, and action list.
3137 * The source command now accepts a -s option to force searching for the
3138 script in the source search path even if the script name specifies
3141 * New features in the GDB remote stub, GDBserver
3143 - GDBserver now support tracepoints (including fast tracepoints, and
3144 static tracepoints). The feature is currently supported by the
3145 i386-linux and amd64-linux builds. See the "Tracepoints support
3146 in gdbserver" section in the manual for more information.
3148 GDBserver JIT compiles the tracepoint's conditional agent
3149 expression bytecode into native code whenever possible for low
3150 overhead dynamic tracepoints conditionals. For such tracepoints,
3151 an expression that examines program state is evaluated when the
3152 tracepoint is reached, in order to determine whether to capture
3153 trace data. If the condition is simple and false, processing the
3154 tracepoint finishes very quickly and no data is gathered.
3156 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3157 for static tracepoints support.
3159 - GDBserver now supports x86_64 Windows 64-bit debugging.
3161 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3162 it understands register description.
3164 * The --batch flag now disables pagination and queries.
3166 * X86 general purpose registers
3168 GDB now supports reading/writing byte, word and double-word x86
3169 general purpose registers directly. This means you can use, say,
3170 $ah or $ax to refer, respectively, to the byte register AH and
3171 16-bit word register AX that are actually portions of the 32-bit
3172 register EAX or 64-bit register RAX.
3174 * The `commands' command now accepts a range of breakpoints to modify.
3175 A plain `commands' following a command that creates multiple
3176 breakpoints affects all the breakpoints set by that command. This
3177 applies to breakpoints set by `rbreak', and also applies when a
3178 single `break' command creates multiple breakpoints (e.g.,
3179 breakpoints on overloaded c++ functions).
3181 * The `rbreak' command now accepts a filename specification as part of
3182 its argument, limiting the functions selected by the regex to those
3183 in the specified file.
3185 * Support for remote debugging Windows and SymbianOS shared libraries
3186 from Unix hosts has been improved. Non Windows GDB builds now can
3187 understand target reported file names that follow MS-DOS based file
3188 system semantics, such as file names that include drive letters and
3189 use the backslash character as directory separator. This makes it
3190 possible to transparently use the "set sysroot" and "set
3191 solib-search-path" on Unix hosts to point as host copies of the
3192 target's shared libraries. See the new command "set
3193 target-file-system-kind" described below, and the "Commands to
3194 specify files" section in the user manual for more information.
3198 eval template, expressions...
3199 Convert the values of one or more expressions under the control
3200 of the string template to a command line, and call it.
3202 set target-file-system-kind unix|dos-based|auto
3203 show target-file-system-kind
3204 Set or show the assumed file system kind for target reported file
3207 save breakpoints <filename>
3208 Save all current breakpoint definitions to a file suitable for use
3209 in a later debugging session. To read the saved breakpoint
3210 definitions, use the `source' command.
3212 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3215 info static-tracepoint-markers
3216 Display information about static tracepoint markers in the target.
3218 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3219 Define a static tracepoint by probing a marker at the given
3220 function, line, address, or marker ID.
3224 Enable and disable observer mode.
3226 set may-write-registers on|off
3227 set may-write-memory on|off
3228 set may-insert-breakpoints on|off
3229 set may-insert-tracepoints on|off
3230 set may-insert-fast-tracepoints on|off
3231 set may-interrupt on|off
3232 Set individual permissions for GDB effects on the target. Note that
3233 some of these settings can have undesirable or surprising
3234 consequences, particularly when changed in the middle of a session.
3235 For instance, disabling the writing of memory can prevent
3236 breakpoints from being inserted, cause single-stepping to fail, or
3237 even crash your program, if you disable after breakpoints have been
3238 inserted. However, GDB should not crash.
3240 set record memory-query on|off
3241 show record memory-query
3242 Control whether to stop the inferior if memory changes caused
3243 by an instruction cannot be recorded.
3248 The disassemble command now supports "start,+length" form of two arguments.
3252 ** GDB now provides a new directory location, called the python directory,
3253 where Python scripts written for GDB can be installed. The location
3254 of that directory is <data-directory>/python, where <data-directory>
3255 is the GDB data directory. For more details, see section `Scripting
3256 GDB using Python' in the manual.
3258 ** The GDB Python API now has access to breakpoints, symbols, symbol
3259 tables, program spaces, inferiors, threads and frame's code blocks.
3260 Additionally, GDB Parameters can now be created from the API, and
3261 manipulated via set/show in the CLI.
3263 ** New functions gdb.target_charset, gdb.target_wide_charset,
3264 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3266 ** New exception gdb.GdbError.
3268 ** Pretty-printers are now also looked up in the current program space.
3270 ** Pretty-printers can now be individually enabled and disabled.
3272 ** GDB now looks for names of Python scripts to auto-load in a
3273 special section named `.debug_gdb_scripts', in addition to looking
3274 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3276 * Tracepoint actions were unified with breakpoint commands. In particular,
3277 there are no longer differences in "info break" output for breakpoints and
3278 tracepoints and the "commands" command can be used for both tracepoints and
3279 regular breakpoints.
3283 ARM Symbian arm*-*-symbianelf*
3285 * D language support.
3286 GDB now supports debugging programs written in the D programming
3289 * GDB now supports the extended ptrace interface for PowerPC which is
3290 available since Linux kernel version 2.6.34. This automatically enables
3291 any hardware breakpoints and additional hardware watchpoints available in
3292 the processor. The old ptrace interface exposes just one hardware
3293 watchpoint and no hardware breakpoints.
3295 * GDB is now able to use the Data Value Compare (DVC) register available on
3296 embedded PowerPC processors to implement in hardware simple watchpoint
3297 conditions of the form:
3299 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3301 This works in native GDB running on Linux kernels with the extended ptrace
3302 interface mentioned above.
3304 *** Changes in GDB 7.1
3308 ** Namespace Support
3310 GDB now supports importing of namespaces in C++. This enables the
3311 user to inspect variables from imported namespaces. Support for
3312 namepace aliasing has also been added. So, if a namespace is
3313 aliased in the current scope (e.g. namepace C=A; ) the user can
3314 print variables using the alias (e.g. (gdb) print C::x).
3318 All known bugs relating to the printing of virtual base class were
3319 fixed. It is now possible to call overloaded static methods using a
3324 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3325 and reinterpret_cast<> are now handled by the C++ expression parser.
3329 Xilinx MicroBlaze microblaze-*-*
3334 Xilinx MicroBlaze microblaze
3337 * Multi-program debugging.
3339 GDB now has support for multi-program (a.k.a. multi-executable or
3340 multi-exec) debugging. This allows for debugging multiple inferiors
3341 simultaneously each running a different program under the same GDB
3342 session. See "Debugging Multiple Inferiors and Programs" in the
3343 manual for more information. This implied some user visible changes
3344 in the multi-inferior support. For example, "info inferiors" now
3345 lists inferiors that are not running yet or that have exited
3346 already. See also "New commands" and "New options" below.
3348 * New tracing features
3350 GDB's tracepoint facility now includes several new features:
3352 ** Trace state variables
3354 GDB tracepoints now include support for trace state variables, which
3355 are variables managed by the target agent during a tracing
3356 experiment. They are useful for tracepoints that trigger each
3357 other, so for instance one tracepoint can count hits in a variable,
3358 and then a second tracepoint has a condition that is true when the
3359 count reaches a particular value. Trace state variables share the
3360 $-syntax of GDB convenience variables, and can appear in both
3361 tracepoint actions and condition expressions. Use the "tvariable"
3362 command to create, and "info tvariables" to view; see "Trace State
3363 Variables" in the manual for more detail.
3367 GDB now includes an option for defining fast tracepoints, which
3368 targets may implement more efficiently, such as by installing a jump
3369 into the target agent rather than a trap instruction. The resulting
3370 speedup can be by two orders of magnitude or more, although the
3371 tradeoff is that some program locations on some target architectures
3372 might not allow fast tracepoint installation, for instance if the
3373 instruction to be replaced is shorter than the jump. To request a
3374 fast tracepoint, use the "ftrace" command, with syntax identical to
3375 the regular trace command.
3377 ** Disconnected tracing
3379 It is now possible to detach GDB from the target while it is running
3380 a trace experiment, then reconnect later to see how the experiment
3381 is going. In addition, a new variable disconnected-tracing lets you
3382 tell the target agent whether to continue running a trace if the
3383 connection is lost unexpectedly.
3387 GDB now has the ability to save the trace buffer into a file, and
3388 then use that file as a target, similarly to you can do with
3389 corefiles. You can select trace frames, print data that was
3390 collected in them, and use tstatus to display the state of the
3391 tracing run at the moment that it was saved. To create a trace
3392 file, use "tsave <filename>", and to use it, do "target tfile
3395 ** Circular trace buffer
3397 You can ask the target agent to handle the trace buffer as a
3398 circular buffer, discarding the oldest trace frames to make room for
3399 newer ones, by setting circular-trace-buffer to on. This feature may
3400 not be available for all target agents.
3405 The disassemble command, when invoked with two arguments, now requires
3406 the arguments to be comma-separated.
3409 The info variables command now displays variable definitions. Files
3410 which only declare a variable are not shown.
3413 The source command is now capable of sourcing Python scripts.
3414 This feature is dependent on the debugger being build with Python
3417 Related to this enhancement is also the introduction of a new command
3418 "set script-extension" (see below).
3420 * New commands (for set/show, see "New options" below)
3422 record save [<FILENAME>]
3423 Save a file (in core file format) containing the process record
3424 execution log for replay debugging at a later time.
3426 record restore <FILENAME>
3427 Restore the process record execution log that was saved at an
3428 earlier time, for replay debugging.
3430 add-inferior [-copies <N>] [-exec <FILENAME>]
3433 clone-inferior [-copies <N>] [ID]
3434 Make a new inferior ready to execute the same program another
3435 inferior has loaded.
3440 maint info program-spaces
3441 List the program spaces loaded into GDB.
3443 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3444 show remote interrupt-sequence
3445 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3446 as the sequence to the remote target in order to interrupt the execution.
3447 Ctrl-C is a default. Some system prefers BREAK which is high level of
3448 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3449 Magic SysRq g. It is BREAK signal and character 'g'.
3451 set remote interrupt-on-connect [on | off]
3452 show remote interrupt-on-connect
3453 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3454 remote target when gdb connects to it. This is needed when you debug
3457 set remotebreak [on | off]
3459 Deprecated. Use "set/show remote interrupt-sequence" instead.
3461 tvariable $NAME [ = EXP ]
3462 Create or modify a trace state variable.
3465 List trace state variables and their values.
3467 delete tvariable $NAME ...
3468 Delete one or more trace state variables.
3471 Evaluate the given expressions without collecting anything into the
3472 trace buffer. (Valid in tracepoint actions only.)
3474 ftrace FN / FILE:LINE / *ADDR
3475 Define a fast tracepoint at the given function, line, or address.
3477 * New expression syntax
3479 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3480 GDB now parses 0b101010 identically with 42.
3484 set follow-exec-mode new|same
3485 show follow-exec-mode
3486 Control whether GDB reuses the same inferior across an exec call or
3487 creates a new one. This is useful to be able to restart the old
3488 executable after the inferior having done an exec call.
3490 set default-collect EXPR, ...
3491 show default-collect
3492 Define a list of expressions to be collected at each tracepoint.
3493 This is a useful way to ensure essential items are not overlooked,
3494 such as registers or a critical global variable.
3496 set disconnected-tracing
3497 show disconnected-tracing
3498 If set to 1, the target is instructed to continue tracing if it
3499 loses its connection to GDB. If 0, the target is to stop tracing
3502 set circular-trace-buffer
3503 show circular-trace-buffer
3504 If set to on, the target is instructed to use a circular trace buffer
3505 and discard the oldest trace frames instead of stopping the trace due
3506 to a full trace buffer. If set to off, the trace stops when the buffer
3507 fills up. Some targets may not support this.
3509 set script-extension off|soft|strict
3510 show script-extension
3511 If set to "off", the debugger does not perform any script language
3512 recognition, and all sourced files are assumed to be GDB scripts.
3513 If set to "soft" (the default), files are sourced according to
3514 filename extension, falling back to GDB scripts if the first
3516 If set to "strict", files are sourced according to filename extension.
3518 set ada trust-PAD-over-XVS on|off
3519 show ada trust-PAD-over-XVS
3520 If off, activate a workaround against a bug in the debugging information
3521 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3522 the GCC sources for more information about the GNAT encoding and
3523 PAD types in particular). It is always safe to set this option to
3524 off, but this introduces a slight performance penalty. The default
3527 * Python API Improvements
3529 ** GDB provides the new class gdb.LazyString. This is useful in
3530 some pretty-printing cases. The new method gdb.Value.lazy_string
3531 provides a simple way to create objects of this type.
3533 ** The fields returned by gdb.Type.fields now have an
3534 `is_base_class' attribute.
3536 ** The new method gdb.Type.range returns the range of an array type.
3538 ** The new method gdb.parse_and_eval can be used to parse and
3539 evaluate an expression.
3541 * New remote packets
3544 Define a trace state variable.
3547 Get the current value of a trace state variable.
3550 Set desired tracing behavior upon disconnection.
3553 Set the trace buffer to be linear or circular.
3556 Get data about the tracepoints currently in use.
3560 Process record now works correctly with hardware watchpoints.
3562 Multiple bug fixes have been made to the mips-irix port, making it
3563 much more reliable. In particular:
3564 - Debugging threaded applications is now possible again. Previously,
3565 GDB would hang while starting the program, or while waiting for
3566 the program to stop at a breakpoint.
3567 - Attaching to a running process no longer hangs.
3568 - An error occurring while loading a core file has been fixed.
3569 - Changing the value of the PC register now works again. This fixes
3570 problems observed when using the "jump" command, or when calling
3571 a function from GDB, or even when assigning a new value to $pc.
3572 - With the "finish" and "return" commands, the return value for functions
3573 returning a small array is now correctly printed.
3574 - It is now possible to break on shared library code which gets executed
3575 during a shared library init phase (code executed while executing
3576 their .init section). Previously, the breakpoint would have no effect.
3577 - GDB is now able to backtrace through the signal handler for
3578 non-threaded programs.
3580 PIE (Position Independent Executable) programs debugging is now supported.
3581 This includes debugging execution of PIC (Position Independent Code) shared
3582 libraries although for that, it should be possible to run such libraries as an
3585 *** Changes in GDB 7.0
3587 * GDB now has an interface for JIT compilation. Applications that
3588 dynamically generate code can create symbol files in memory and register
3589 them with GDB. For users, the feature should work transparently, and
3590 for JIT developers, the interface is documented in the GDB manual in the
3591 "JIT Compilation Interface" chapter.
3593 * Tracepoints may now be conditional. The syntax is as for
3594 breakpoints; either an "if" clause appended to the "trace" command,
3595 or the "condition" command is available. GDB sends the condition to
3596 the target for evaluation using the same bytecode format as is used
3597 for tracepoint actions.
3599 * The disassemble command now supports: an optional /r modifier, print the
3600 raw instructions in hex as well as in symbolic form, and an optional /m
3601 modifier to print mixed source+assembly.
3603 * Process record and replay
3605 In a architecture environment that supports ``process record and
3606 replay'', ``process record and replay'' target can record a log of
3607 the process execution, and replay it with both forward and reverse
3610 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3611 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3612 set execution-direction {forward|reverse}, for targets that support
3615 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3616 feature is available with a native GDB running on kernel version
3619 * GDB now has support for multi-byte and wide character sets on the
3620 target. Strings whose character type is wchar_t, char16_t, or
3621 char32_t are now correctly printed. GDB supports wide- and unicode-
3622 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3623 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3624 `printf'. This feature requires iconv to work properly; if your
3625 system does not have a working iconv, GDB can use GNU libiconv. See
3626 the installation instructions for more information.
3628 * GDB now supports automatic retrieval of shared library files from
3629 remote targets. To use this feature, specify a system root that begins
3630 with the `remote:' prefix, either via the `set sysroot' command or via
3631 the `--with-sysroot' configure-time option.
3633 * "info sharedlibrary" now takes an optional regex of libraries to show,
3634 and it now reports if a shared library has no debugging information.
3636 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3637 now complete on file names.
3639 * When completing in expressions, gdb will attempt to limit
3640 completions to allowable structure or union fields, where appropriate.
3641 For instance, consider:
3643 # struct example { int f1; double f2; };
3644 # struct example variable;
3647 If the user types TAB at the end of this command line, the available
3648 completions will be "f1" and "f2".
3650 * Inlined functions are now supported. They show up in backtraces, and
3651 the "step", "next", and "finish" commands handle them automatically.
3653 * GDB now supports the token-splicing (##) and stringification (#)
3654 operators when expanding macros. It also supports variable-arity
3657 * GDB now supports inspecting extra signal information, exported by
3658 the new $_siginfo convenience variable. The feature is currently
3659 implemented on linux ARM, i386 and amd64.
3661 * GDB can now display the VFP floating point registers and NEON vector
3662 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3663 can provide these registers (requires Linux 2.6.30 or later). Remote
3664 and simulator targets may also provide them.
3666 * New remote packets
3669 Search memory for a sequence of bytes.
3672 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3673 operation over reliable transport links. Use of this packet is
3674 controlled by the `set remote noack-packet' command.
3677 Kill the process with the specified process ID. Use this in preference
3678 to `k' when multiprocess protocol extensions are supported.
3681 Obtains additional operating system information
3685 Read or write additional signal information.
3687 * Removed remote protocol undocumented extension
3689 An undocumented extension to the remote protocol's `S' stop reply
3690 packet that permited the stub to pass a process id was removed.
3691 Remote servers should use the `T' stop reply packet instead.
3693 * GDB now supports multiple function calling conventions according to the
3694 DWARF-2 DW_AT_calling_convention function attribute.
3696 * The SH target utilizes the aforementioned change to distinguish between gcc
3697 and Renesas calling convention. It also adds the new CLI commands
3698 `set/show sh calling-convention'.
3700 * GDB can now read compressed debug sections, as produced by GNU gold
3701 with the --compress-debug-sections=zlib flag.
3703 * 64-bit core files are now supported on AIX.
3705 * Thread switching is now supported on Tru64.
3707 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3708 which will be allocated using malloc later in program execution.
3710 * The qXfer:libraries:read remote procotol packet now allows passing a
3711 list of section offsets.
3713 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3714 conditions handling signals delivered during attach or thread creation
3715 have also been fixed.
3717 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3718 From the user's standpoint, all unqualified instances of True and False
3719 are treated as the standard definitions, regardless of context.
3721 * GDB now parses C++ symbol and type names more flexibly. For
3724 template<typename T> class C { };
3727 GDB will now correctly handle all of:
3729 ptype C<char const *>
3730 ptype C<char const*>
3731 ptype C<const char *>
3732 ptype C<const char*>
3734 * New features in the GDB remote stub, gdbserver
3736 - The "--wrapper" command-line argument tells gdbserver to use a
3737 wrapper program to launch programs for debugging.
3739 - On PowerPC and S/390 targets, it is now possible to use a single
3740 gdbserver executable to debug both 32-bit and 64-bit programs.
3741 (This requires gdbserver itself to be built as a 64-bit executable.)
3743 - gdbserver uses the new noack protocol mode for TCP connections to
3744 reduce communications latency, if also supported and enabled in GDB.
3746 - Support for the sparc64-linux-gnu target is now included in
3749 - The amd64-linux build of gdbserver now supports debugging both
3750 32-bit and 64-bit programs.
3752 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3753 now support hardware watchpoints, and will use them automatically
3758 GDB now has support for scripting using Python. Whether this is
3759 available is determined at configure time.
3761 New GDB commands can now be written in Python.
3763 * Ada tasking support
3765 Ada tasks can now be inspected in GDB. The following commands have
3769 Print the list of Ada tasks.
3771 Print detailed information about task number N.
3773 Print the task number of the current task.
3775 Switch the context of debugging to task number N.
3777 * Support for user-defined prefixed commands. The "define" command can
3778 add new commands to existing prefixes, e.g. "target".
3780 * Multi-inferior, multi-process debugging.
3782 GDB now has generalized support for multi-inferior debugging. See
3783 "Debugging Multiple Inferiors" in the manual for more information.
3784 Although availability still depends on target support, the command
3785 set is more uniform now. The GNU/Linux specific multi-forks support
3786 has been migrated to this new framework. This implied some user
3787 visible changes; see "New commands" and also "Removed commands"
3790 * Target descriptions can now describe the target OS ABI. See the
3791 "Target Description Format" section in the user manual for more
3794 * Target descriptions can now describe "compatible" architectures
3795 to indicate that the target can execute applications for a different
3796 architecture in addition to those for the main target architecture.
3797 See the "Target Description Format" section in the user manual for
3800 * Multi-architecture debugging.
3802 GDB now includes general supports for debugging applications on
3803 hybrid systems that use more than one single processor architecture
3804 at the same time. Each such hybrid architecture still requires
3805 specific support to be added. The only hybrid architecture supported
3806 in this version of GDB is the Cell Broadband Engine.
3808 * GDB now supports integrated debugging of Cell/B.E. applications that
3809 use both the PPU and SPU architectures. To enable support for hybrid
3810 Cell/B.E. debugging, you need to configure GDB to support both the
3811 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3812 --enable-targets configure option.
3814 * Non-stop mode debugging.
3816 For some targets, GDB now supports an optional mode of operation in
3817 which you can examine stopped threads while other threads continue
3818 to execute freely. This is referred to as non-stop mode, with the
3819 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3820 section in the user manual for more information.
3822 To be able to support remote non-stop debugging, a remote stub needs
3823 to implement the non-stop mode remote protocol extensions, as
3824 described in the "Remote Non-Stop" section of the user manual. The
3825 GDB remote stub, gdbserver, has been adjusted to support these
3826 extensions on linux targets.
3828 * New commands (for set/show, see "New options" below)
3830 catch syscall [NAME(S) | NUMBER(S)]
3831 Catch system calls. Arguments, which should be names of system
3832 calls or their numbers, mean catch only those syscalls. Without
3833 arguments, every syscall will be caught. When the inferior issues
3834 any of the specified syscalls, GDB will stop and announce the system
3835 call, both when it is called and when its call returns. This
3836 feature is currently available with a native GDB running on the
3837 Linux Kernel, under the following architectures: x86, x86_64,
3838 PowerPC and PowerPC64.
3840 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3842 Search memory for a sequence of bytes.
3844 maint set python print-stack
3845 maint show python print-stack
3846 Show a stack trace when an error is encountered in a Python script.
3849 Invoke CODE by passing it to the Python interpreter.
3854 These allow macros to be defined, undefined, and listed
3858 Show operating system information about processes.
3861 List the inferiors currently under GDB's control.
3864 Switch focus to inferior number NUM.
3867 Detach from inferior number NUM.
3870 Kill inferior number NUM.
3874 set spu stop-on-load
3875 show spu stop-on-load
3876 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3878 set spu auto-flush-cache
3879 show spu auto-flush-cache
3880 Control whether to automatically flush the software-managed cache
3881 during Cell/B.E. debugging.
3883 set sh calling-convention
3884 show sh calling-convention
3885 Control the calling convention used when calling SH target functions.
3888 show debug timestamp
3889 Control display of timestamps with GDB debugging output.
3891 set disassemble-next-line
3892 show disassemble-next-line
3893 Control display of disassembled source lines or instructions when
3896 set remote noack-packet
3897 show remote noack-packet
3898 Set/show the use of remote protocol QStartNoAckMode packet. See above
3899 under "New remote packets."
3901 set remote query-attached-packet
3902 show remote query-attached-packet
3903 Control use of remote protocol `qAttached' (query-attached) packet.
3905 set remote read-siginfo-object
3906 show remote read-siginfo-object
3907 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3910 set remote write-siginfo-object
3911 show remote write-siginfo-object
3912 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3915 set remote reverse-continue
3916 show remote reverse-continue
3917 Control use of remote protocol 'bc' (reverse-continue) packet.
3919 set remote reverse-step
3920 show remote reverse-step
3921 Control use of remote protocol 'bs' (reverse-step) packet.
3923 set displaced-stepping
3924 show displaced-stepping
3925 Control displaced stepping mode. Displaced stepping is a way to
3926 single-step over breakpoints without removing them from the debuggee.
3927 Also known as "out-of-line single-stepping".
3930 show debug displaced
3931 Control display of debugging info for displaced stepping.
3933 maint set internal-error
3934 maint show internal-error
3935 Control what GDB does when an internal error is detected.
3937 maint set internal-warning
3938 maint show internal-warning
3939 Control what GDB does when an internal warning is detected.
3944 Use a wrapper program to launch programs for debugging.
3946 set multiple-symbols (all|ask|cancel)
3947 show multiple-symbols
3948 The value of this variable can be changed to adjust the debugger behavior
3949 when an expression or a breakpoint location contains an ambiguous symbol
3950 name (an overloaded function name, for instance).
3952 set breakpoint always-inserted
3953 show breakpoint always-inserted
3954 Keep breakpoints always inserted in the target, as opposed to inserting
3955 them when resuming the target, and removing them when the target stops.
3956 This option can improve debugger performance on slow remote targets.
3958 set arm fallback-mode (arm|thumb|auto)
3959 show arm fallback-mode
3960 set arm force-mode (arm|thumb|auto)
3962 These commands control how ARM GDB determines whether instructions
3963 are ARM or Thumb. The default for both settings is auto, which uses
3964 the current CPSR value for instructions without symbols; previous
3965 versions of GDB behaved as if "set arm fallback-mode arm".
3967 set disable-randomization
3968 show disable-randomization
3969 Standalone programs run with the virtual address space randomization enabled
3970 by default on some platforms. This option keeps the addresses stable across
3971 multiple debugging sessions.
3975 Control whether other threads are stopped or not when some thread hits
3980 Requests that asynchronous execution is enabled in the target, if available.
3981 In this case, it's possible to resume target in the background, and interact
3982 with GDB while the target is running. "show target-async" displays the
3983 current state of asynchronous execution of the target.
3985 set target-wide-charset
3986 show target-wide-charset
3987 The target-wide-charset is the name of the character set that GDB
3988 uses when printing characters whose type is wchar_t.
3990 set tcp auto-retry (on|off)
3992 set tcp connect-timeout
3993 show tcp connect-timeout
3994 These commands allow GDB to retry failed TCP connections to a remote stub
3995 with a specified timeout period; this is useful if the stub is launched
3996 in parallel with GDB but may not be ready to accept connections immediately.
3998 set libthread-db-search-path
3999 show libthread-db-search-path
4000 Control list of directories which GDB will search for appropriate
4003 set schedule-multiple (on|off)
4004 show schedule-multiple
4005 Allow GDB to resume all threads of all processes or only threads of
4006 the current process.
4010 Use more aggressive caching for accesses to the stack. This improves
4011 performance of remote debugging (particularly backtraces) without
4012 affecting correctness.
4014 set interactive-mode (on|off|auto)
4015 show interactive-mode
4016 Control whether GDB runs in interactive mode (on) or not (off).
4017 When in interactive mode, GDB waits for the user to answer all
4018 queries. Otherwise, GDB does not wait and assumes the default
4019 answer. When set to auto (the default), GDB determines which
4020 mode to use based on the stdin settings.
4025 For program forks, this is replaced by the new more generic `info
4026 inferiors' command. To list checkpoints, you can still use the
4027 `info checkpoints' command, which was an alias for the `info forks'
4031 Replaced by the new `inferior' command. To switch between
4032 checkpoints, you can still use the `restart' command, which was an
4033 alias for the `fork' command.
4036 This is removed, since some targets don't have a notion of
4037 processes. To switch between processes, you can still use the
4038 `inferior' command using GDB's own inferior number.
4041 For program forks, this is replaced by the new more generic `kill
4042 inferior' command. To delete a checkpoint, you can still use the
4043 `delete checkpoint' command, which was an alias for the `delete
4047 For program forks, this is replaced by the new more generic `detach
4048 inferior' command. To detach a checkpoint, you can still use the
4049 `detach checkpoint' command, which was an alias for the `detach
4052 * New native configurations
4054 x86/x86_64 Darwin i[34567]86-*-darwin*
4056 x86_64 MinGW x86_64-*-mingw*
4060 Lattice Mico32 lm32-*
4061 x86 DICOS i[34567]86-*-dicos*
4062 x86_64 DICOS x86_64-*-dicos*
4065 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4066 (mingw32ce) debugging.
4072 These commands were actually not implemented on any target.
4074 *** Changes in GDB 6.8
4076 * New native configurations
4078 NetBSD/hppa hppa*-*netbsd*
4079 Xtensa GNU/Linux xtensa*-*-linux*
4083 NetBSD/hppa hppa*-*-netbsd*
4084 Xtensa GNU/Lunux xtensa*-*-linux*
4086 * Change in command line behavior -- corefiles vs. process ids.
4088 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4089 attaching to process NUMBER fails, GDB no longer attempts to open a
4090 core file named NUMBER. Attaching to a program using the -c option
4091 is no longer supported. Instead, use the '-p' or '--pid' options.
4093 * GDB can now be built as a native debugger for debugging Windows x86
4094 (mingw32) Portable Executable (PE) programs.
4096 * Pending breakpoints no longer change their number when their address
4099 * GDB now supports breakpoints with multiple locations,
4100 including breakpoints on C++ constructors, inside C++ templates,
4101 and in inlined functions.
4103 * GDB's ability to debug optimized code has been improved. GDB more
4104 accurately identifies function bodies and lexical blocks that occupy
4105 more than one contiguous range of addresses.
4107 * Target descriptions can now describe registers for PowerPC.
4109 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4110 registers on PowerPC targets.
4112 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4113 targets even when the libthread_db library is not available.
4115 * The GDB remote stub, gdbserver, now supports the new file transfer
4116 commands (remote put, remote get, and remote delete).
4118 * The GDB remote stub, gdbserver, now supports run and attach in
4119 extended-remote mode.
4121 * hppa*64*-*-hpux11* target broken
4122 The debugger is unable to start a program and fails with the following
4123 error: "Error trying to get information about dynamic linker".
4124 The gdb-6.7 release is also affected.
4126 * GDB now supports the --enable-targets= configure option to allow
4127 building a single GDB executable that supports multiple remote
4128 target architectures.
4130 * GDB now supports debugging C and C++ programs which use the
4131 Decimal Floating Point extension. In addition, the PowerPC target
4132 now has a set of pseudo-registers to inspect decimal float values
4133 stored in two consecutive float registers.
4135 * The -break-insert MI command can optionally create pending
4138 * Improved support for debugging Ada
4139 Many improvements to the Ada language support have been made. These
4141 - Better support for Ada2005 interface types
4142 - Improved handling of arrays and slices in general
4143 - Better support for Taft-amendment types
4144 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4146 - Improved command completion in Ada
4149 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4154 set print frame-arguments (all|scalars|none)
4155 show print frame-arguments
4156 The value of this variable can be changed to control which argument
4157 values should be printed by the debugger when displaying a frame.
4162 Transfer files to and from a remote target, and delete remote files.
4169 Transfer files to and from a remote target, and delete remote files.
4171 * New remote packets
4178 Open, close, read, write, and delete files on the remote system.
4181 Attach to an existing process on the remote system, in extended-remote
4185 Run a new process on the remote system, in extended-remote mode.
4187 *** Changes in GDB 6.7
4189 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4190 bfd, libiberty and opcodes, as revealed by static analysis donated by
4191 Coverity, Inc. (http://scan.coverity.com).
4193 * When looking up multiply-defined global symbols, GDB will now prefer the
4194 symbol definition in the current shared library if it was built using the
4195 -Bsymbolic linker option.
4197 * When the Text User Interface (TUI) is not configured, GDB will now
4198 recognize the -tui command-line option and print a message that the TUI
4201 * The GDB remote stub, gdbserver, now has lower overhead for high
4202 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4204 * GDB for MIPS targets now autodetects whether a remote target provides
4205 32-bit or 64-bit register values.
4207 * Support for C++ member pointers has been improved.
4209 * GDB now understands XML target descriptions, which specify the
4210 target's overall architecture. GDB can read a description from
4211 a local file or over the remote serial protocol.
4213 * Vectors of single-byte data use a new integer type which is not
4214 automatically displayed as character or string data.
4216 * The /s format now works with the print command. It displays
4217 arrays of single-byte integers and pointers to single-byte integers
4220 * Target descriptions can now describe target-specific registers,
4221 for architectures which have implemented the support (currently
4222 only ARM, M68K, and MIPS).
4224 * GDB and the GDB remote stub, gdbserver, now support the XScale
4227 * The GDB remote stub, gdbserver, has been updated to support
4228 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4229 has been rewritten to use the standard GDB remote protocol.
4231 * GDB can now step into C++ functions which are called through thunks.
4233 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4235 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4236 layout. It also supports a TextSeg= and DataSeg= response when only
4237 segment base addresses (rather than offsets) are available.
4239 * The /i format now outputs any trailing branch delay slot instructions
4240 immediately following the last instruction within the count specified.
4242 * The GDB remote protocol "T" stop reply packet now supports a
4243 "library" response. Combined with the new "qXfer:libraries:read"
4244 packet, this response allows GDB to debug shared libraries on targets
4245 where the operating system manages the list of loaded libraries (e.g.
4246 Windows and SymbianOS).
4248 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4249 (DLLs) on Windows and Windows CE targets.
4251 * GDB now supports a faster verification that a .debug file matches its binary
4252 according to its build-id signature, if the signature is present.
4258 Enable or disable hardware flow control (RTS/CTS) on the serial port
4259 when debugging using remote targets.
4261 set mem inaccessible-by-default
4262 show mem inaccessible-by-default
4263 If the target supplies a memory map, for instance via the remote
4264 protocol's "qXfer:memory-map:read" packet, setting this variable
4265 prevents GDB from accessing memory outside the memory map. This
4266 is useful for targets with memory mapped registers or which react
4267 badly to accesses of unmapped address space.
4269 set breakpoint auto-hw
4270 show breakpoint auto-hw
4271 If the target supplies a memory map, for instance via the remote
4272 protocol's "qXfer:memory-map:read" packet, setting this variable
4273 lets GDB use hardware breakpoints automatically for memory regions
4274 where it can not use software breakpoints. This covers both the
4275 "break" command and internal breakpoints used for other commands
4276 including "next" and "finish".
4279 catch exception unhandled
4280 Stop the program execution when Ada exceptions are raised.
4283 Stop the program execution when an Ada assertion failed.
4287 Set an alternate system root for target files. This is a more
4288 general version of "set solib-absolute-prefix", which is now
4289 an alias to "set sysroot".
4292 Provide extended SPU facility status information. This set of
4293 commands is available only when debugging the Cell/B.E. SPU
4296 * New native configurations
4298 OpenBSD/sh sh*-*openbsd*
4301 unset tdesc filename
4303 Use the specified local file as an XML target description, and do
4304 not query the target for its built-in description.
4308 OpenBSD/sh sh*-*-openbsd*
4309 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4310 Toshiba Media Processor mep-elf
4312 * New remote packets
4315 Ignore the specified signals; pass them directly to the debugged program
4316 without stopping other threads or reporting them to GDB.
4318 qXfer:features:read:
4319 Read an XML target description from the target, which describes its
4324 Read or write contents of an spufs file on the target system. These
4325 packets are available only on the Cell/B.E. SPU architecture.
4327 qXfer:libraries:read:
4328 Report the loaded shared libraries. Combined with new "T" packet
4329 response, this packet allows GDB to debug shared libraries on
4330 targets where the operating system manages the list of loaded
4331 libraries (e.g. Windows and SymbianOS).
4335 Support for these obsolete configurations has been removed.
4343 i[34567]86-*-lynxos*
4344 i[34567]86-*-netware*
4345 i[34567]86-*-sco3.2v5*
4346 i[34567]86-*-sco3.2v4*
4348 i[34567]86-*-sysv4.2*
4351 i[34567]86-*-unixware2*
4352 i[34567]86-*-unixware*
4361 * Other removed features
4368 Various m68k-only ROM monitors.
4375 Various Renesas ROM monitors and debugging interfaces for SH and
4380 Support for a Macraigor serial interface to on-chip debugging.
4381 GDB does not directly support the newer parallel or USB
4386 A debug information format. The predecessor to DWARF 2 and
4387 DWARF 3, which are still supported.
4389 Support for the HP aCC compiler on HP-UX/PA-RISC
4391 SOM-encapsulated symbolic debugging information, automatic
4392 invocation of pxdb, and the aCC custom C++ ABI. This does not
4393 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4394 with aCC can still be debugged on an assembly level.
4396 MIPS ".pdr" sections
4398 A MIPS-specific format used to describe stack frame layout
4399 in debugging information.
4403 GDB could work with an older version of Guile to debug
4404 the interpreter and Scheme programs running in it.
4406 set mips stack-arg-size
4407 set mips saved-gpreg-size
4409 Use "set mips abi" to control parameter passing for MIPS.
4411 *** Changes in GDB 6.6
4416 Cell Broadband Engine SPU spu-elf
4418 * GDB can now be configured as a cross-debugger targeting native Windows
4419 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4420 running on a Windows system over TCP/IP to debug Windows programs.
4422 * The GDB remote stub, gdbserver, has been updated to support Windows and
4423 Cygwin debugging. Both single-threaded and multi-threaded programs are
4426 * The "set trust-readonly-sections" command works again. This command was
4427 broken in GDB 6.3, 6.4, and 6.5.
4429 * The "load" command now supports writing to flash memory, if the remote
4430 stub provides the required support.
4432 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4433 longer requires symbolic debug information (e.g. DWARF-2).
4438 unset substitute-path
4439 show substitute-path
4440 Manage a list of substitution rules that GDB uses to rewrite the name
4441 of the directories where the sources are located. This can be useful
4442 for instance when the sources were moved to a different location
4443 between compilation and debugging.
4447 Print each CLI command as it is executed. Each command is prefixed with
4448 a number of `+' symbols representing the nesting depth.
4449 The source command now has a `-v' option to enable the same feature.
4453 The ARM Demon monitor support (RDP protocol, "target rdp").
4455 Kernel Object Display, an embedded debugging feature which only worked with
4456 an obsolete version of Cisco IOS.
4458 The 'set download-write-size' and 'show download-write-size' commands.
4460 * New remote packets
4463 Tell a stub about GDB client features, and request remote target features.
4464 The first feature implemented is PacketSize, which allows the target to
4465 specify the size of packets it can handle - to minimize the number of
4466 packets required and improve performance when connected to a remote
4470 Fetch an OS auxilliary vector from the remote stub. This packet is a
4471 more efficient replacement for qPart:auxv:read.
4473 qXfer:memory-map:read:
4474 Fetch a memory map from the remote stub, including information about
4475 RAM, ROM, and flash memory devices.
4480 Erase and program a flash memory device.
4482 * Removed remote packets
4485 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4486 used it, and only gdbserver implemented it.
4488 *** Changes in GDB 6.5
4492 Renesas M32C/M16C m32c-elf
4494 Morpho Technologies ms1 ms1-elf
4498 init-if-undefined Initialize a convenience variable, but
4499 only if it doesn't already have a value.
4501 The following commands are presently only implemented for native GNU/Linux:
4503 checkpoint Save a snapshot of the program state.
4505 restart <n> Return the program state to a
4506 previously saved state.
4508 info checkpoints List currently saved checkpoints.
4510 delete-checkpoint <n> Delete a previously saved checkpoint.
4512 set|show detach-on-fork Tell gdb whether to detach from a newly
4513 forked process, or to keep debugging it.
4515 info forks List forks of the user program that
4516 are available to be debugged.
4518 fork <n> Switch to debugging one of several
4519 forks of the user program that are
4520 available to be debugged.
4522 delete-fork <n> Delete a fork from the list of forks
4523 that are available to be debugged (and
4524 kill the forked process).
4526 detach-fork <n> Delete a fork from the list of forks
4527 that are available to be debugged (and
4528 allow the process to continue).
4532 Morpho Technologies ms2 ms1-elf
4534 * Improved Windows host support
4536 GDB now builds as a cross debugger hosted on i686-mingw32, including
4537 native console support, and remote communications using either
4538 network sockets or serial ports.
4540 * Improved Modula-2 language support
4542 GDB can now print most types in the Modula-2 syntax. This includes:
4543 basic types, set types, record types, enumerated types, range types,
4544 pointer types and ARRAY types. Procedure var parameters are correctly
4545 printed and hexadecimal addresses and character constants are also
4546 written in the Modula-2 syntax. Best results can be obtained by using
4547 GNU Modula-2 together with the -gdwarf-2 command line option.
4551 The ARM rdi-share module.
4553 The Netware NLM debug server.
4555 *** Changes in GDB 6.4
4557 * New native configurations
4559 OpenBSD/arm arm*-*-openbsd*
4560 OpenBSD/mips64 mips64-*-openbsd*
4564 Morpho Technologies ms1 ms1-elf
4566 * New command line options
4568 --batch-silent As for --batch, but totally silent.
4569 --return-child-result The debugger will exist with the same value
4570 the child (debugged) program exited with.
4571 --eval-command COMMAND, -ex COMMAND
4572 Execute a single GDB CLI command. This may be
4573 specified multiple times and in conjunction
4574 with the --command (-x) option.
4576 * Deprecated commands removed
4578 The following commands, that were deprecated in 2000, have been
4582 set|show arm disassembly-flavor set|show arm disassembler
4583 othernames set arm disassembler
4584 set|show remotedebug set|show debug remote
4585 set|show archdebug set|show debug arch
4586 set|show eventdebug set|show debug event
4589 * New BSD user-level threads support
4591 It is now possible to debug programs using the user-level threads
4592 library on OpenBSD and FreeBSD. Currently supported (target)
4595 FreeBSD/amd64 x86_64-*-freebsd*
4596 FreeBSD/i386 i386-*-freebsd*
4597 OpenBSD/i386 i386-*-openbsd*
4599 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4600 are not yet supported.
4602 * New support for Matsushita MN10300 w/sim added
4603 (Work in progress). mn10300-elf.
4605 * REMOVED configurations and files
4607 VxWorks and the XDR protocol *-*-vxworks
4608 Motorola MCORE mcore-*-*
4609 National Semiconductor NS32000 ns32k-*-*
4611 * New "set print array-indexes" command
4613 After turning this setting "on", GDB prints the index of each element
4614 when displaying arrays. The default is "off" to preserve the previous
4617 * VAX floating point support
4619 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4621 * User-defined command support
4623 In addition to using $arg0..$arg9 for argument passing, it is now possible
4624 to use $argc to determine now many arguments have been passed. See the
4625 section on user-defined commands in the user manual for more information.
4627 *** Changes in GDB 6.3:
4629 * New command line option
4631 GDB now accepts -l followed by a number to set the timeout for remote
4634 * GDB works with GCC -feliminate-dwarf2-dups
4636 GDB now supports a more compact representation of DWARF-2 debug
4637 information using DW_FORM_ref_addr references. These are produced
4638 by GCC with the option -feliminate-dwarf2-dups and also by some
4639 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4640 to use -feliminate-dwarf2-dups.
4642 * Internationalization
4644 When supported by the host system, GDB will be built with
4645 internationalization (libintl). The task of marking up the sources is
4646 continued, we're looking forward to our first translation.
4650 Initial support for debugging programs compiled with the GNAT
4651 implementation of the Ada programming language has been integrated
4652 into GDB. In this release, support is limited to expression evaluation.
4654 * New native configurations
4656 GNU/Linux/m32r m32r-*-linux-gnu
4660 GDB's remote protocol now includes support for the 'p' packet. This
4661 packet is used to fetch individual registers from a remote inferior.
4663 * END-OF-LIFE registers[] compatibility module
4665 GDB's internal register infrastructure has been completely rewritten.
4666 The new infrastructure making possible the implementation of key new
4667 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4670 GDB 6.3 will be the last release to include the the registers[]
4671 compatibility module that allowed out-of-date configurations to
4672 continue to work. This change directly impacts the following
4682 powerpc bdm protocol
4684 Unless there is activity to revive these configurations, they will be
4685 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4687 * OBSOLETE configurations and files
4689 Configurations that have been declared obsolete in this release have
4690 been commented out. Unless there is activity to revive these
4691 configurations, the next release of GDB will have their sources
4692 permanently REMOVED.
4701 *** Changes in GDB 6.2.1:
4703 * MIPS `break main; run' gave an heuristic-fence-post warning
4705 When attempting to run even a simple program, a warning about
4706 heuristic-fence-post being hit would be reported. This problem has
4709 * MIPS IRIX 'long double' crashed GDB
4711 When examining a long double variable, GDB would get a segmentation
4712 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4713 IRIX long double values).
4717 A bug in the VAX stack code was causing problems with the "next"
4718 command. This problem has been fixed.
4720 *** Changes in GDB 6.2:
4722 * Fix for ``many threads''
4724 On GNU/Linux systems that use the NPTL threads library, a program
4725 rapidly creating and deleting threads would confuse GDB leading to the
4728 ptrace: No such process.
4729 thread_db_get_info: cannot get thread info: generic error
4731 This problem has been fixed.
4733 * "-async" and "-noasync" options removed.
4735 Support for the broken "-noasync" option has been removed (it caused
4738 * New ``start'' command.
4740 This command runs the program until the begining of the main procedure.
4742 * New BSD Kernel Data Access Library (libkvm) interface
4744 Using ``target kvm'' it is now possible to debug kernel core dumps and
4745 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4746 platforms. Currently supported (native-only) configurations are:
4748 FreeBSD/amd64 x86_64-*-freebsd*
4749 FreeBSD/i386 i?86-*-freebsd*
4750 NetBSD/i386 i?86-*-netbsd*
4751 NetBSD/m68k m68*-*-netbsd*
4752 NetBSD/sparc sparc-*-netbsd*
4753 OpenBSD/amd64 x86_64-*-openbsd*
4754 OpenBSD/i386 i?86-*-openbsd*
4755 OpenBSD/m68k m68*-openbsd*
4756 OpenBSD/sparc sparc-*-openbsd*
4758 * Signal trampoline code overhauled
4760 Many generic problems with GDB's signal handling code have been fixed.
4761 These include: backtraces through non-contiguous stacks; recognition
4762 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4763 call; backtrace through a signal trampoline; step into and out of
4764 signal handlers; and single-stepping in the signal trampoline.
4766 Please note that kernel bugs are a limiting factor here. These
4767 features have been shown to work on an s390 GNU/Linux system that
4768 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4770 * Cygwin support for DWARF 2 added.
4772 * New native configurations
4774 GNU/Linux/hppa hppa*-*-linux*
4775 OpenBSD/hppa hppa*-*-openbsd*
4776 OpenBSD/m68k m68*-*-openbsd*
4777 OpenBSD/m88k m88*-*-openbsd*
4778 OpenBSD/powerpc powerpc-*-openbsd*
4779 NetBSD/vax vax-*-netbsd*
4780 OpenBSD/vax vax-*-openbsd*
4782 * END-OF-LIFE frame compatibility module
4784 GDB's internal frame infrastructure has been completely rewritten.
4785 The new infrastructure making it possible to support key new features
4786 including DWARF 2 Call Frame Information. To aid in the task of
4787 migrating old configurations to this new infrastructure, a
4788 compatibility module, that allowed old configurations to continue to
4789 work, was also included.
4791 GDB 6.2 will be the last release to include this frame compatibility
4792 module. This change directly impacts the following configurations:
4802 Unless there is activity to revive these configurations, they will be
4803 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4805 * REMOVED configurations and files
4807 Sun 3, running SunOS 3 m68*-*-sunos3*
4808 Sun 3, running SunOS 4 m68*-*-sunos4*
4809 Sun 2, running SunOS 3 m68000-*-sunos3*
4810 Sun 2, running SunOS 4 m68000-*-sunos4*
4811 Motorola 680x0 running LynxOS m68*-*-lynxos*
4812 AT&T 3b1/Unix pc m68*-att-*
4813 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4814 decstation mips-dec-* mips-little-*
4815 riscos mips-*-riscos* mips-*-sysv*
4816 sonymips mips-sony-*
4817 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4819 *** Changes in GDB 6.1.1:
4821 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4823 The TUI (Text-mode User Interface) is now built as part of a default
4824 GDB configuration. It is enabled by either selecting the TUI with the
4825 command line option "-i=tui" or by running the separate "gdbtui"
4826 program. For more information on the TUI, see the manual "Debugging
4829 * Pending breakpoint support (also included in GDB 6.1)
4831 Support has been added to allow you to specify breakpoints in shared
4832 libraries that have not yet been loaded. If a breakpoint location
4833 cannot be found, and the "breakpoint pending" option is set to auto,
4834 GDB queries you if you wish to make the breakpoint pending on a future
4835 shared-library load. If and when GDB resolves the breakpoint symbol,
4836 the pending breakpoint is removed as one or more regular breakpoints
4839 Pending breakpoints are very useful for GCJ Java debugging.
4841 * Fixed ISO-C build problems
4843 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4844 non ISO-C code that stopped them being built using a more strict ISO-C
4845 compiler (e.g., IBM's C compiler).
4847 * Fixed build problem on IRIX 5
4849 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4850 wasn't able to compile compile on an IRIX 5 system.
4852 * Added execute permission to gdb/gdbserver/configure
4854 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4855 permission. This bug would cause configure to fail on a number of
4856 systems (Solaris, IRIX). Ref: server/519.
4858 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4860 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4861 has been updated to use constant array sizes.
4863 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4865 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4866 its generated DWARF Call Frame Info. This encoding was causing GDB to
4867 panic, that panic has been fixed. Ref: gdb/1628.
4869 * Fixed a problem when examining parameters in shared library code.
4871 When examining parameters in optimized shared library code generated
4872 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4873 not available''. GDB now correctly displays the variable's value.
4875 *** Changes in GDB 6.1:
4877 * Removed --with-mmalloc
4879 Support for the mmalloc memory manager has been removed, as it
4880 conflicted with the internal gdb byte cache.
4882 * Changes in AMD64 configurations
4884 The AMD64 target now includes the %cs and %ss registers. As a result
4885 the AMD64 remote protocol has changed; this affects the floating-point
4886 and SSE registers. If you rely on those registers for your debugging,
4887 you should upgrade gdbserver on the remote side.
4889 * Revised SPARC target
4891 The SPARC target has been completely revised, incorporating the
4892 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4893 support for LynxOS and SunOS 4 has been dropped. Calling functions
4894 from within GDB on operating systems with a non-executable stack
4895 (Solaris, OpenBSD) now works.
4899 GDB has a new C++ demangler which does a better job on the mangled
4900 names generated by current versions of g++. It also runs faster, so
4901 with this and other changes gdb should now start faster on large C++
4904 * DWARF 2 Location Expressions
4906 GDB support for location expressions has been extended to support function
4907 arguments and frame bases. Older versions of GDB could crash when they
4910 * C++ nested types and namespaces
4912 GDB's support for nested types and namespaces in C++ has been
4913 improved, especially if you use the DWARF 2 debugging format. (This
4914 is the default for recent versions of GCC on most platforms.)
4915 Specifically, if you have a class "Inner" defined within a class or
4916 namespace "Outer", then GDB realizes that the class's name is
4917 "Outer::Inner", not simply "Inner". This should greatly reduce the
4918 frequency of complaints about not finding RTTI symbols. In addition,
4919 if you are stopped at inside of a function defined within a namespace,
4920 GDB modifies its name lookup accordingly.
4922 * New native configurations
4924 NetBSD/amd64 x86_64-*-netbsd*
4925 OpenBSD/amd64 x86_64-*-openbsd*
4926 OpenBSD/alpha alpha*-*-openbsd*
4927 OpenBSD/sparc sparc-*-openbsd*
4928 OpenBSD/sparc64 sparc64-*-openbsd*
4930 * New debugging protocols
4932 M32R with SDI protocol m32r-*-elf*
4934 * "set prompt-escape-char" command deleted.
4936 The command "set prompt-escape-char" has been deleted. This command,
4937 and its very obscure effet on GDB's prompt, was never documented,
4938 tested, nor mentioned in the NEWS file.
4940 * OBSOLETE configurations and files
4942 Configurations that have been declared obsolete in this release have
4943 been commented out. Unless there is activity to revive these
4944 configurations, the next release of GDB will have their sources
4945 permanently REMOVED.
4947 Sun 3, running SunOS 3 m68*-*-sunos3*
4948 Sun 3, running SunOS 4 m68*-*-sunos4*
4949 Sun 2, running SunOS 3 m68000-*-sunos3*
4950 Sun 2, running SunOS 4 m68000-*-sunos4*
4951 Motorola 680x0 running LynxOS m68*-*-lynxos*
4952 AT&T 3b1/Unix pc m68*-att-*
4953 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4954 decstation mips-dec-* mips-little-*
4955 riscos mips-*-riscos* mips-*-sysv*
4956 sonymips mips-sony-*
4957 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4959 * REMOVED configurations and files
4961 SGI Irix-4.x mips-sgi-irix4 or iris4
4962 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4963 Z8000 simulator z8k-zilog-none or z8ksim
4964 Matsushita MN10200 w/simulator mn10200-*-*
4965 H8/500 simulator h8500-hitachi-hms or h8500hms
4966 HP/PA running BSD hppa*-*-bsd*
4967 HP/PA running OSF/1 hppa*-*-osf*
4968 HP/PA Pro target hppa*-*-pro*
4969 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4970 386BSD i[3456]86-*-bsd*
4971 Sequent family i[3456]86-sequent-sysv4*
4972 i[3456]86-sequent-sysv*
4973 i[3456]86-sequent-bsd*
4974 SPARC running LynxOS sparc-*-lynxos*
4975 SPARC running SunOS 4 sparc-*-sunos4*
4976 Tsqware Sparclet sparclet-*-*
4977 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4979 *** Changes in GDB 6.0:
4983 Support for debugging the Objective-C programming language has been
4984 integrated into GDB.
4986 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4988 DWARF 2's Call Frame Information makes available compiler generated
4989 information that more exactly describes the program's run-time stack.
4990 By using this information, GDB is able to provide more robust stack
4993 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4994 have been updated to use a new backtrace mechanism which includes
4995 DWARF 2 CFI support.
4999 GDB's remote protocol has been extended to include support for hosted
5000 file I/O (where the remote target uses GDB's file system). See GDB's
5001 remote protocol documentation for details.
5003 * All targets using the new architecture framework.
5005 All of GDB's targets have been updated to use the new internal
5006 architecture framework. The way is now open for future GDB releases
5007 to include cross-architecture native debugging support (i386 on amd64,
5010 * GNU/Linux's Thread Local Storage (TLS)
5012 GDB now includes support for for the GNU/Linux implementation of
5013 per-thread variables.
5015 * GNU/Linux's Native POSIX Thread Library (NPTL)
5017 GDB's thread code has been updated to work with either the new
5018 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5020 * Separate debug info.
5022 GDB, in conjunction with BINUTILS, now supports a mechanism for
5023 automatically loading debug information from a separate file. Instead
5024 of shipping full debug and non-debug versions of system libraries,
5025 system integrators can now instead ship just the stripped libraries
5026 and optional debug files.
5028 * DWARF 2 Location Expressions
5030 DWARF 2 Location Expressions allow the compiler to more completely
5031 describe the location of variables (even in optimized code) to the
5034 GDB now includes preliminary support for location expressions (support
5035 for DW_OP_piece is still missing).
5039 A number of long standing bugs that caused GDB to die while starting a
5040 Java application have been fixed. GDB's Java support is now
5041 considered "useable".
5043 * GNU/Linux support for fork, vfork, and exec.
5045 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5046 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5049 * GDB supports logging output to a file
5051 There are two new commands, "set logging" and "show logging", which can be
5052 used to capture GDB's output to a file.
5054 * The meaning of "detach" has changed for gdbserver
5056 The "detach" command will now resume the application, as documented. To
5057 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5060 * d10v, m68hc11 `regs' command deprecated
5062 The `info registers' command has been updated so that it displays the
5063 registers using a format identical to the old `regs' command.
5067 A new command, "maint set profile on/off", has been added. This command can
5068 be used to enable or disable profiling while running GDB, to profile a
5069 session or a set of commands. In addition there is a new configure switch,
5070 "--enable-profiling", which will cause GDB to be compiled with profiling
5071 data, for more informative profiling results.
5073 * Default MI syntax changed to "mi2".
5075 The default MI (machine interface) syntax, enabled by the command line
5076 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5077 "mi1", can be enabled by specifying the option "-i=mi1".
5079 Support for the original "mi0" syntax (included in GDB 5.0) has been
5082 Fix for gdb/192: removed extraneous space when displaying frame level.
5083 Fix for gdb/672: update changelist is now output in mi list format.
5084 Fix for gdb/702: a -var-assign that updates the value now shows up
5085 in a subsequent -var-update.
5087 * New native configurations.
5089 FreeBSD/amd64 x86_64-*-freebsd*
5091 * Multi-arched targets.
5093 HP/PA HPUX11 hppa*-*-hpux*
5094 Renesas M32R/D w/simulator m32r-*-elf*
5096 * OBSOLETE configurations and files
5098 Configurations that have been declared obsolete in this release have
5099 been commented out. Unless there is activity to revive these
5100 configurations, the next release of GDB will have their sources
5101 permanently REMOVED.
5103 Z8000 simulator z8k-zilog-none or z8ksim
5104 Matsushita MN10200 w/simulator mn10200-*-*
5105 H8/500 simulator h8500-hitachi-hms or h8500hms
5106 HP/PA running BSD hppa*-*-bsd*
5107 HP/PA running OSF/1 hppa*-*-osf*
5108 HP/PA Pro target hppa*-*-pro*
5109 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5110 Sequent family i[3456]86-sequent-sysv4*
5111 i[3456]86-sequent-sysv*
5112 i[3456]86-sequent-bsd*
5113 Tsqware Sparclet sparclet-*-*
5114 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5116 * REMOVED configurations and files
5119 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5120 IBM AIX PS/2 i[3456]86-*-aix
5121 i386 running Mach 3.0 i[3456]86-*-mach3*
5122 i386 running Mach i[3456]86-*-mach*
5123 i386 running OSF/1 i[3456]86-*osf1mk*
5124 HP/Apollo 68k Family m68*-apollo*-sysv*,
5126 m68*-hp-bsd*, m68*-hp-hpux*
5127 Argonaut Risc Chip (ARC) arc-*-*
5128 Mitsubishi D30V d30v-*-*
5129 Fujitsu FR30 fr30-*-elf*
5130 OS/9000 i[34]86-*-os9k
5131 I960 with MON960 i960-*-coff
5133 * MIPS $fp behavior changed
5135 The convenience variable $fp, for the MIPS, now consistently returns
5136 the address of the current frame's base. Previously, depending on the
5137 context, $fp could refer to either $sp or the current frame's base
5138 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5139 The GNU Source-Level Debugger''.
5141 *** Changes in GDB 5.3:
5143 * GNU/Linux shared library multi-threaded performance improved.
5145 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5146 `/proc', in preference to `ptrace' for memory reads. This may result
5147 in an improvement in the start-up time of multi-threaded, shared
5148 library applications when run under GDB. One GDB user writes: ``loads
5149 shared libs like mad''.
5151 * ``gdbserver'' now supports multi-threaded applications on some targets
5153 Support for debugging multi-threaded applications which use
5154 the GNU/Linux LinuxThreads package has been added for
5155 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5156 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5158 * GDB now supports C/C++ preprocessor macros.
5160 GDB now expands preprocessor macro invocations in C/C++ expressions,
5161 and provides various commands for showing macro definitions and how
5164 The new command `macro expand EXPRESSION' expands any macro
5165 invocations in expression, and shows the result.
5167 The new command `show macro MACRO-NAME' shows the definition of the
5168 macro named MACRO-NAME, and where it was defined.
5170 Most compilers don't include information about macros in the debugging
5171 information by default. In GCC 3.1, for example, you need to compile
5172 your program with the options `-gdwarf-2 -g3'. If the macro
5173 information is present in the executable, GDB will read it.
5175 * Multi-arched targets.
5177 DEC Alpha (partial) alpha*-*-*
5178 DEC VAX (partial) vax-*-*
5180 National Semiconductor NS32000 (partial) ns32k-*-*
5181 Motorola 68000 (partial) m68k-*-*
5182 Motorola MCORE mcore-*-*
5186 Fujitsu FRV architecture added by Red Hat frv*-*-*
5189 * New native configurations
5191 Alpha NetBSD alpha*-*-netbsd*
5192 SH NetBSD sh*-*-netbsdelf*
5193 MIPS NetBSD mips*-*-netbsd*
5194 UltraSPARC NetBSD sparc64-*-netbsd*
5196 * OBSOLETE configurations and files
5198 Configurations that have been declared obsolete in this release have
5199 been commented out. Unless there is activity to revive these
5200 configurations, the next release of GDB will have their sources
5201 permanently REMOVED.
5203 Mitsubishi D30V d30v-*-*
5204 OS/9000 i[34]86-*-os9k
5205 IBM AIX PS/2 i[3456]86-*-aix
5206 Fujitsu FR30 fr30-*-elf*
5207 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5208 Argonaut Risc Chip (ARC) arc-*-*
5209 i386 running Mach 3.0 i[3456]86-*-mach3*
5210 i386 running Mach i[3456]86-*-mach*
5211 i386 running OSF/1 i[3456]86-*osf1mk*
5212 HP/Apollo 68k Family m68*-apollo*-sysv*,
5214 m68*-hp-bsd*, m68*-hp-hpux*
5215 I960 with MON960 i960-*-coff
5217 * OBSOLETE languages
5219 CHILL, a Pascal like language used by telecommunications companies.
5221 * REMOVED configurations and files
5223 AMD 29k family via UDI a29k-amd-udi, udi29k
5224 A29K VxWorks a29k-*-vxworks
5225 AMD 29000 embedded, using EBMON a29k-none-none
5226 AMD 29000 embedded with COFF a29k-none-coff
5227 AMD 29000 embedded with a.out a29k-none-aout
5229 testsuite/gdb.hp/gdb.threads-hp/ directory
5231 * New command "set max-user-call-depth <nnn>"
5233 This command allows the user to limit the call depth of user-defined
5234 commands. The default is 1024.
5236 * Changes in FreeBSD/i386 native debugging.
5238 Support for the "generate-core-file" has been added.
5240 * New commands "dump", "append", and "restore".
5242 These commands allow data to be copied from target memory
5243 to a bfd-format or binary file (dump and append), and back
5244 from a file into memory (restore).
5246 * Improved "next/step" support on multi-processor Alpha Tru64.
5248 The previous single-step mechanism could cause unpredictable problems,
5249 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5250 of a software single-step mechanism prevents this.
5252 *** Changes in GDB 5.2.1:
5260 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5261 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5262 Fix, by Joel Brobecker imported from mainline.
5264 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5265 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5266 Fix, by Fred Fish, imported from mainline.
5268 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5269 Surprisingly enough, it works now.
5270 By Michal Ludvig, imported from mainline.
5272 i386 hardware watchpoint support:
5273 avoid misses on second run for some targets.
5274 By Pierre Muller, imported from mainline.
5276 *** Changes in GDB 5.2:
5278 * New command "set trust-readonly-sections on[off]".
5280 This command is a hint that tells gdb that read-only sections
5281 really are read-only (ie. that their contents will not change).
5282 In this mode, gdb will go to the object file rather than the
5283 target to read memory from read-only sections (such as ".text").
5284 This can be a significant performance improvement on some
5285 (notably embedded) targets.
5287 * New command "generate-core-file" (or "gcore").
5289 This new gdb command allows the user to drop a core file of the child
5290 process state at any time. So far it's been implemented only for
5291 GNU/Linux and Solaris, but should be relatively easily ported to other
5292 hosts. Argument is core file name (defaults to core.<pid>).
5294 * New command line option
5296 GDB now accepts --pid or -p followed by a process id.
5298 * Change in command line behavior -- corefiles vs. process ids.
5300 There is a subtle behavior in the way in which GDB handles
5301 command line arguments. The first non-flag argument is always
5302 a program to debug, but the second non-flag argument may either
5303 be a corefile or a process id. Previously, GDB would attempt to
5304 open the second argument as a corefile, and if that failed, would
5305 issue a superfluous error message and then attempt to attach it as
5306 a process. Now, if the second argument begins with a non-digit,
5307 it will be treated as a corefile. If it begins with a digit,
5308 GDB will attempt to attach it as a process, and if no such process
5309 is found, will then attempt to open it as a corefile.
5311 * Changes in ARM configurations.
5313 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5314 configuration is fully multi-arch.
5316 * New native configurations
5318 ARM NetBSD arm*-*-netbsd*
5319 x86 OpenBSD i[3456]86-*-openbsd*
5320 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5321 Sparc64 running FreeBSD sparc64-*-freebsd*
5325 Sanyo XStormy16 xstormy16-elf
5327 * OBSOLETE configurations and files
5329 Configurations that have been declared obsolete in this release have
5330 been commented out. Unless there is activity to revive these
5331 configurations, the next release of GDB will have their sources
5332 permanently REMOVED.
5334 AMD 29k family via UDI a29k-amd-udi, udi29k
5335 A29K VxWorks a29k-*-vxworks
5336 AMD 29000 embedded, using EBMON a29k-none-none
5337 AMD 29000 embedded with COFF a29k-none-coff
5338 AMD 29000 embedded with a.out a29k-none-aout
5340 testsuite/gdb.hp/gdb.threads-hp/ directory
5342 * REMOVED configurations and files
5344 TI TMS320C80 tic80-*-*
5346 PowerPC Solaris powerpcle-*-solaris*
5347 PowerPC Windows NT powerpcle-*-cygwin32
5348 PowerPC Netware powerpc-*-netware*
5349 Harris/CXUX m88k m88*-harris-cxux*
5350 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5351 ns32k-utek-sysv* ns32k-utek-*
5352 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5353 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5354 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5355 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5356 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5358 * Changes to command line processing
5360 The new `--args' feature can be used to specify command-line arguments
5361 for the inferior from gdb's command line.
5363 * Changes to key bindings
5365 There is a new `operate-and-get-next' function bound to `C-o'.
5367 *** Changes in GDB 5.1.1
5369 Fix compile problem on DJGPP.
5371 Fix a problem with floating-point registers on the i386 being
5374 Fix to stop GDB crashing on .debug_str debug info.
5376 Numerous documentation fixes.
5378 Numerous testsuite fixes.
5380 *** Changes in GDB 5.1:
5382 * New native configurations
5384 Alpha FreeBSD alpha*-*-freebsd*
5385 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5386 MIPS GNU/Linux mips*-*-linux*
5387 MIPS SGI Irix 6.x mips*-sgi-irix6*
5388 ia64 AIX ia64-*-aix*
5389 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5393 Motorola 68HC11 and 68HC12 m68hc11-elf
5395 UltraSparc running GNU/Linux sparc64-*-linux*
5397 * OBSOLETE configurations and files
5399 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5400 Harris/CXUX m88k m88*-harris-cxux*
5401 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5402 ns32k-utek-sysv* ns32k-utek-*
5403 TI TMS320C80 tic80-*-*
5405 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5406 PowerPC Solaris powerpcle-*-solaris*
5407 PowerPC Windows NT powerpcle-*-cygwin32
5408 PowerPC Netware powerpc-*-netware*
5409 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5410 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5411 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5412 Apple Macintosh (MPW) host N/A
5414 stuff.c (Program to stuff files into a specially prepared space in kdb)
5415 kdb-start.c (Main loop for the standalone kernel debugger)
5417 Configurations that have been declared obsolete in this release have
5418 been commented out. Unless there is activity to revive these
5419 configurations, the next release of GDB will have their sources
5420 permanently REMOVED.
5422 * REMOVED configurations and files
5424 Altos 3068 m68*-altos-*
5425 Convex c1-*-*, c2-*-*
5427 ARM RISCix arm-*-* (as host)
5431 * GDB has been converted to ISO C.
5433 GDB's source code has been converted to ISO C. In particular, the
5434 sources are fully protoized, and rely on standard headers being
5439 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5441 * The MI enabled by default.
5443 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5444 revised and enabled by default. Packages which use GDB as a debugging
5445 engine behind a UI or another front end are encouraged to switch to
5446 using the GDB/MI interface, instead of the old annotations interface
5447 which is now deprecated.
5449 * Support for debugging Pascal programs.
5451 GDB now includes support for debugging Pascal programs. The following
5452 main features are supported:
5454 - Pascal-specific data types such as sets;
5456 - automatic recognition of Pascal sources based on file-name
5459 - Pascal-style display of data types, variables, and functions;
5461 - a Pascal expression parser.
5463 However, some important features are not yet supported.
5465 - Pascal string operations are not supported at all;
5467 - there are some problems with boolean types;
5469 - Pascal type hexadecimal constants are not supported
5470 because they conflict with the internal variables format;
5472 - support for Pascal objects and classes is not full yet;
5474 - unlike Pascal, GDB is case-sensitive for symbol names.
5476 * Changes in completion.
5478 Commands such as `shell', `run' and `set args', which pass arguments
5479 to inferior programs, now complete on file names, similar to what
5480 users expect at the shell prompt.
5482 Commands which accept locations, such as `disassemble', `print',
5483 `breakpoint', `until', etc. now complete on filenames as well as
5484 program symbols. Thus, if you type "break foob TAB", and the source
5485 files linked into the programs include `foobar.c', that file name will
5486 be one of the candidates for completion. However, file names are not
5487 considered for completion after you typed a colon that delimits a file
5488 name from a name of a function in that file, as in "break foo.c:bar".
5490 `set demangle-style' completes on available demangling styles.
5492 * New platform-independent commands:
5494 It is now possible to define a post-hook for a command as well as a
5495 hook that runs before the command. For more details, see the
5496 documentation of `hookpost' in the GDB manual.
5498 * Changes in GNU/Linux native debugging.
5500 Support for debugging multi-threaded programs has been completely
5501 revised for all platforms except m68k and sparc. You can now debug as
5502 many threads as your system allows you to have.
5504 Attach/detach is supported for multi-threaded programs.
5506 Support for SSE registers was added for x86. This doesn't work for
5507 multi-threaded programs though.
5509 * Changes in MIPS configurations.
5511 Multi-arch support is enabled for all MIPS configurations.
5513 GDB can now be built as native debugger on SGI Irix 6.x systems for
5514 debugging n32 executables. (Debugging 64-bit executables is not yet
5517 * Unified support for hardware watchpoints in all x86 configurations.
5519 Most (if not all) native x86 configurations support hardware-assisted
5520 breakpoints and watchpoints in a unified manner. This support
5521 implements debug register sharing between watchpoints, which allows to
5522 put a virtually infinite number of watchpoints on the same address,
5523 and also supports watching regions up to 16 bytes with several debug
5526 The new maintenance command `maintenance show-debug-regs' toggles
5527 debugging print-outs in functions that insert, remove, and test
5528 watchpoints and hardware breakpoints.
5530 * Changes in the DJGPP native configuration.
5532 New command ``info dos sysinfo'' displays assorted information about
5533 the CPU, OS, memory, and DPMI server.
5535 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5536 display information about segment descriptors stored in GDT, LDT, and
5539 New commands ``info dos pde'' and ``info dos pte'' display entries
5540 from Page Directory and Page Tables (for now works with CWSDPMI only).
5541 New command ``info dos address-pte'' displays the Page Table entry for
5542 a given linear address.
5544 GDB can now pass command lines longer than 126 characters to the
5545 program being debugged (requires an update to the libdbg.a library
5546 which is part of the DJGPP development kit).
5548 DWARF2 debug info is now supported.
5550 It is now possible to `step' and `next' through calls to `longjmp'.
5552 * Changes in documentation.
5554 All GDB documentation was converted to GFDL, the GNU Free
5555 Documentation License.
5557 Tracepoints-related commands are now fully documented in the GDB
5560 TUI, the Text-mode User Interface, is now documented in the manual.
5562 Tracepoints-related commands are now fully documented in the GDB
5565 The "GDB Internals" manual now has an index. It also includes
5566 documentation of `ui_out' functions, GDB coding standards, x86
5567 hardware watchpoints, and memory region attributes.
5569 * GDB's version number moved to ``version.in''
5571 The Makefile variable VERSION has been replaced by the file
5572 ``version.in''. People creating GDB distributions should update the
5573 contents of this file.
5577 GUD support is now a standard part of the EMACS distribution.
5579 *** Changes in GDB 5.0:
5581 * Improved support for debugging FP programs on x86 targets
5583 Unified and much-improved support for debugging floating-point
5584 programs on all x86 targets. In particular, ``info float'' now
5585 displays the FP registers in the same format on all x86 targets, with
5586 greater level of detail.
5588 * Improvements and bugfixes in hardware-assisted watchpoints
5590 It is now possible to watch array elements, struct members, and
5591 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5592 on x86 targets no longer erroneously trigger when the address is
5595 * Improvements in the native DJGPP version of GDB
5597 The distribution now includes all the scripts and auxiliary files
5598 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5599 machines ``out of the box''.
5601 The DJGPP version can now debug programs that use signals. It is
5602 possible to catch signals that happened in the debuggee, deliver
5603 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5604 would kill the program being debugged.) Programs that hook hardware
5605 interrupts (keyboard, timer, etc.) can also be debugged.
5607 It is now possible to debug DJGPP programs that redirect their
5608 standard handles or switch them to raw (as opposed to cooked) mode, or
5609 even close them. The command ``run < foo > bar'' works as expected,
5610 and ``info terminal'' reports useful information about the debuggee's
5611 terminal, including raw/cooked mode, redirection, etc.
5613 The DJGPP version now uses termios functions for console I/O, which
5614 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5617 DOS-style file names with drive letters are now fully supported by
5620 It is now possible to debug DJGPP programs that switch their working
5621 directory. It is also possible to rerun the debuggee any number of
5622 times without restarting GDB; thus, you can use the same setup,
5623 breakpoints, etc. for many debugging sessions.
5625 * New native configurations
5627 ARM GNU/Linux arm*-*-linux*
5628 PowerPC GNU/Linux powerpc-*-linux*
5632 Motorola MCore mcore-*-*
5633 x86 VxWorks i[3456]86-*-vxworks*
5634 PowerPC VxWorks powerpc-*-vxworks*
5635 TI TMS320C80 tic80-*-*
5637 * OBSOLETE configurations
5639 Altos 3068 m68*-altos-*
5640 Convex c1-*-*, c2-*-*
5642 ARM RISCix arm-*-* (as host)
5645 Configurations that have been declared obsolete will be commented out,
5646 but the code will be left in place. If there is no activity to revive
5647 these configurations before the next release of GDB, the sources will
5648 be permanently REMOVED.
5650 * Gould support removed
5652 Support for the Gould PowerNode and NP1 has been removed.
5654 * New features for SVR4
5656 On SVR4 native platforms (such as Solaris), if you attach to a process
5657 without first loading a symbol file, GDB will now attempt to locate and
5658 load symbols from the running process's executable file.
5660 * Many C++ enhancements
5662 C++ support has been greatly improved. Overload resolution now works properly
5663 in almost all cases. RTTI support is on the way.
5665 * Remote targets can connect to a sub-program
5667 A popen(3) style serial-device has been added. This device starts a
5668 sub-process (such as a stand-alone simulator) and then communicates
5669 with that. The sub-program to run is specified using the syntax
5670 ``|<program> <args>'' vis:
5672 (gdb) set remotedebug 1
5673 (gdb) target extended-remote |mn10300-elf-sim program-args
5675 * MIPS 64 remote protocol
5677 A long standing bug in the mips64 remote protocol where by GDB
5678 expected certain 32 bit registers (ex SR) to be transfered as 32
5679 instead of 64 bits has been fixed.
5681 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5682 added to provide backward compatibility with older versions of GDB.
5684 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5686 The command ``set remotebinarydownload'' command has been replaced by
5687 ``set remote X-packet''. Other commands in ``set remote'' family
5688 include ``set remote P-packet''.
5690 * Breakpoint commands accept ranges.
5692 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5693 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5694 ``tracepoint passcount'' also accepts a range of tracepoints.
5696 * ``apropos'' command added.
5698 The ``apropos'' command searches through command names and
5699 documentation strings, printing out matches, making it much easier to
5700 try to find a command that does what you are looking for.
5704 A new machine oriented interface (MI) has been added to GDB. This
5705 interface is designed for debug environments running GDB as a separate
5706 process. This is part of the long term libGDB project. See the
5707 "GDB/MI" chapter of the GDB manual for further information. It can be
5708 enabled by configuring with:
5710 .../configure --enable-gdbmi
5712 *** Changes in GDB-4.18:
5714 * New native configurations
5716 HP-UX 10.20 hppa*-*-hpux10.20
5717 HP-UX 11.x hppa*-*-hpux11.0*
5718 M68K GNU/Linux m68*-*-linux*
5722 Fujitsu FR30 fr30-*-elf*
5723 Intel StrongARM strongarm-*-*
5724 Mitsubishi D30V d30v-*-*
5726 * OBSOLETE configurations
5728 Gould PowerNode, NP1 np1-*-*, pn-*-*
5730 Configurations that have been declared obsolete will be commented out,
5731 but the code will be left in place. If there is no activity to revive
5732 these configurations before the next release of GDB, the sources will
5733 be permanently REMOVED.
5737 As a compatibility experiment, GDB's source files buildsym.h and
5738 buildsym.c have been converted to pure standard C, no longer
5739 containing any K&R compatibility code. We believe that all systems in
5740 use today either come with a standard C compiler, or have a GCC port
5741 available. If this is not true, please report the affected
5742 configuration to bug-gdb@gnu.org immediately. See the README file for
5743 information about getting a standard C compiler if you don't have one
5748 GDB now uses readline 2.2.
5750 * set extension-language
5752 You can now control the mapping between filename extensions and source
5753 languages by using the `set extension-language' command. For instance,
5754 you can ask GDB to treat .c files as C++ by saying
5755 set extension-language .c c++
5756 The command `info extensions' lists all of the recognized extensions
5757 and their associated languages.
5759 * Setting processor type for PowerPC and RS/6000
5761 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5762 you can use the `set processor' command to specify what variant of the
5763 PowerPC family you are debugging. The command
5767 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5768 following PowerPC and RS6000 variants:
5770 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5771 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5773 403GC IBM PowerPC 403GC
5774 505 Motorola PowerPC 505
5775 860 Motorola PowerPC 860 or 850
5776 601 Motorola PowerPC 601
5777 602 Motorola PowerPC 602
5778 603 Motorola/IBM PowerPC 603 or 603e
5779 604 Motorola PowerPC 604 or 604e
5780 750 Motorola/IBM PowerPC 750 or 750
5782 At the moment, this command just tells GDB what to name the
5783 special-purpose processor registers. Since almost all the affected
5784 registers are inaccessible to user-level programs, this command is
5785 only useful for remote debugging in its present form.
5789 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5790 more extensive support for HP-UX. Added features include shared
5791 library support, kernel threads and hardware watchpoints for 11.00,
5792 support for HP's ANSI C and C++ compilers, and a compatibility mode
5793 for xdb and dbx commands.
5797 HP's donation includes the new concept of catchpoints, which is a
5798 generalization of the old catch command. On HP-UX, it is now possible
5799 to catch exec, fork, and vfork, as well as library loading.
5801 This means that the existing catch command has changed; its first
5802 argument now specifies the type of catch to be set up. See the
5803 output of "help catch" for a list of catchpoint types.
5805 * Debugging across forks
5807 On HP-UX, you can choose which process to debug when a fork() happens
5812 HP has donated a curses-based terminal user interface (TUI). To get
5813 it, build with --enable-tui. Although this can be enabled for any
5814 configuration, at present it only works for native HP debugging.
5816 * GDB remote protocol additions
5818 A new protocol packet 'X' that writes binary data is now available.
5819 Default behavior is to try 'X', then drop back to 'M' if the stub
5820 fails to respond. The settable variable `remotebinarydownload'
5821 allows explicit control over the use of 'X'.
5823 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5824 full 64-bit address. The command
5826 set remoteaddresssize 32
5828 can be used to revert to the old behaviour. For existing remote stubs
5829 the change should not be noticed, as the additional address information
5832 In order to assist in debugging stubs, you may use the maintenance
5833 command `packet' to send any text string to the stub. For instance,
5835 maint packet heythere
5837 sends the packet "$heythere#<checksum>". Note that it is very easy to
5838 disrupt a debugging session by sending the wrong packet at the wrong
5841 The compare-sections command allows you to compare section data on the
5842 target to what is in the executable file without uploading or
5843 downloading, by comparing CRC checksums.
5845 * Tracing can collect general expressions
5847 You may now collect general expressions at tracepoints. This requires
5848 further additions to the target-side stub; see tracepoint.c and
5849 doc/agentexpr.texi for further details.
5851 * mask-address variable for Mips
5853 For Mips targets, you may control the zeroing of the upper 32 bits of
5854 a 64-bit address by entering `set mask-address on'. This is mainly
5855 of interest to users of embedded R4xxx and R5xxx processors.
5857 * Higher serial baud rates
5859 GDB's serial code now allows you to specify baud rates 57600, 115200,
5860 230400, and 460800 baud. (Note that your host system may not be able
5861 to achieve all of these rates.)
5865 The i960 configuration now includes an initial implementation of a
5866 builtin simulator, contributed by Jim Wilson.
5869 *** Changes in GDB-4.17:
5871 * New native configurations
5873 Alpha GNU/Linux alpha*-*-linux*
5874 Unixware 2.x i[3456]86-unixware2*
5875 Irix 6.x mips*-sgi-irix6*
5876 PowerPC GNU/Linux powerpc-*-linux*
5877 PowerPC Solaris powerpcle-*-solaris*
5878 Sparc GNU/Linux sparc-*-linux*
5879 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5883 Argonaut Risc Chip (ARC) arc-*-*
5884 Hitachi H8/300S h8300*-*-*
5885 Matsushita MN10200 w/simulator mn10200-*-*
5886 Matsushita MN10300 w/simulator mn10300-*-*
5887 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5888 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5889 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5890 Mitsubishi D10V w/simulator d10v-*-*
5891 Mitsubishi M32R/D w/simulator m32r-*-elf*
5892 Tsqware Sparclet sparclet-*-*
5893 NEC V850 w/simulator v850-*-*
5895 * New debugging protocols
5897 ARM with RDI protocol arm*-*-*
5898 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5899 DDB and LSI variants of PMON protocol mips*-*-*
5900 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5901 PowerPC with SDS protocol powerpc{,le}-*-eabi
5902 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5906 All configurations can now understand and use the DWARF 2 debugging
5907 format. The choice is automatic, if the symbol file contains DWARF 2
5912 GDB now includes basic Java language support. This support is
5913 only useful with Java compilers that produce native machine code.
5915 * solib-absolute-prefix and solib-search-path
5917 For SunOS and SVR4 shared libraries, you may now set the prefix for
5918 loading absolute shared library symbol files, and the search path for
5919 locating non-absolute shared library symbol files.
5921 * Live range splitting
5923 GDB can now effectively debug code for which GCC has performed live
5924 range splitting as part of its optimization. See gdb/doc/LRS for
5925 more details on the expected format of the stabs information.
5929 GDB's support for the GNU Hurd, including thread debugging, has been
5930 updated to work with current versions of the Hurd.
5934 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5935 instruction set. ARM GDB automatically detects when Thumb
5936 instructions are in use, and adjusts disassembly and backtracing
5941 GDB's MIPS target configurations now handle the MIP16 16-bit
5946 GDB now includes support for overlays; if an executable has been
5947 linked such that multiple sections are based at the same address, GDB
5948 will decide which section to use for symbolic info. You can choose to
5949 control the decision manually, using overlay commands, or implement
5950 additional target-side support and use "overlay load-target" to bring
5951 in the overlay mapping. Do "help overlay" for more detail.
5955 The command "info symbol <address>" displays information about
5956 the symbol at the specified address.
5960 The standard remote protocol now includes an extension that allows
5961 asynchronous collection and display of trace data. This requires
5962 extensive support in the target-side debugging stub. Tracing mode
5963 includes a new interaction mode in GDB and new commands: see the
5964 file tracepoint.c for more details.
5968 Configurations for embedded MIPS now include a simulator contributed
5969 by Cygnus Solutions. The simulator supports the instruction sets
5970 of most MIPS variants.
5974 Sparc configurations may now include the ERC32 simulator contributed
5975 by the European Space Agency. The simulator is not built into
5976 Sparc targets by default; configure with --enable-sim to include it.
5980 For target configurations that may include multiple variants of a
5981 basic architecture (such as MIPS and SH), you may now set the
5982 architecture explicitly. "set arch" sets, "info arch" lists
5983 the possible architectures.
5985 *** Changes in GDB-4.16:
5987 * New native configurations
5989 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5990 M68K NetBSD m68k-*-netbsd*
5991 PowerPC AIX 4.x powerpc-*-aix*
5992 PowerPC MacOS powerpc-*-macos*
5993 PowerPC Windows NT powerpcle-*-cygwin32
5994 RS/6000 AIX 4.x rs6000-*-aix4*
5998 ARM with RDP protocol arm-*-*
5999 I960 with MON960 i960-*-coff
6000 MIPS VxWorks mips*-*-vxworks*
6001 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6002 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6004 Matra Sparclet sparclet-*-*
6008 The powerpc-eabi configuration now includes the PSIM simulator,
6009 contributed by Andrew Cagney, with assistance from Mike Meissner.
6010 PSIM is a very elaborate model of the PowerPC, including not only
6011 basic instruction set execution, but also details of execution unit
6012 performance and I/O hardware. See sim/ppc/README for more details.
6016 GDB now works with Solaris 2.5.
6018 * Windows 95/NT native
6020 GDB will now work as a native debugger on Windows 95 and Windows NT.
6021 To build it from source, you must use the "gnu-win32" environment,
6022 which uses a DLL to emulate enough of Unix to run the GNU tools.
6023 Further information, binaries, and sources are available at
6024 ftp.cygnus.com, under pub/gnu-win32.
6026 * dont-repeat command
6028 If a user-defined command includes the command `dont-repeat', then the
6029 command will not be repeated if the user just types return. This is
6030 useful if the command is time-consuming to run, so that accidental
6031 extra keystrokes don't run the same command many times.
6033 * Send break instead of ^C
6035 The standard remote protocol now includes an option to send a break
6036 rather than a ^C to the target in order to interrupt it. By default,
6037 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6039 * Remote protocol timeout
6041 The standard remote protocol includes a new variable `remotetimeout'
6042 that allows you to set the number of seconds before GDB gives up trying
6043 to read from the target. The default value is 2.
6045 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6047 By default GDB will automatically keep track of objects as they are
6048 loaded and unloaded by the dynamic linker. By using the command `set
6049 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6050 when shared library events occur, thus allowing you to set breakpoints
6051 in shared libraries which are explicitly loaded by the inferior.
6053 Note this feature does not work on hpux8. On hpux9 you must link
6054 /usr/lib/end.o into your program. This feature should work
6055 automatically on hpux10.
6057 * Irix 5.x hardware watchpoint support
6059 Irix 5 configurations now support the use of hardware watchpoints.
6061 * Mips protocol "SYN garbage limit"
6063 When debugging a Mips target using the `target mips' protocol, you
6064 may set the number of characters that GDB will ignore by setting
6065 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6066 every character. The default value is 1050.
6068 * Recording and replaying remote debug sessions
6070 If you set `remotelogfile' to the name of a file, gdb will write to it
6071 a recording of a remote debug session. This recording may then be
6072 replayed back to gdb using "gdbreplay". See gdbserver/README for
6073 details. This is useful when you have a problem with GDB while doing
6074 remote debugging; you can make a recording of the session and send it
6075 to someone else, who can then recreate the problem.
6077 * Speedups for remote debugging
6079 GDB includes speedups for downloading and stepping MIPS systems using
6080 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6081 and more efficient S-record downloading.
6083 * Memory use reductions and statistics collection
6085 GDB now uses less memory and reports statistics about memory usage.
6086 Try the `maint print statistics' command, for example.
6088 *** Changes in GDB-4.15:
6090 * Psymtabs for XCOFF
6092 The symbol reader for AIX GDB now uses partial symbol tables. This
6093 can greatly improve startup time, especially for large executables.
6095 * Remote targets use caching
6097 Remote targets now use a data cache to speed up communication with the
6098 remote side. The data cache could lead to incorrect results because
6099 it doesn't know about volatile variables, thus making it impossible to
6100 debug targets which use memory mapped I/O devices. `set remotecache
6101 off' turns the the data cache off.
6103 * Remote targets may have threads
6105 The standard remote protocol now includes support for multiple threads
6106 in the target system, using new protocol commands 'H' and 'T'. See
6107 gdb/remote.c for details.
6111 If GDB is configured with `--enable-netrom', then it will include
6112 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6113 acts as though it is a bank of ROM on the target board, but you can
6114 write into it over the network. GDB's support consists only of
6115 support for fast loading into the emulated ROM; to debug, you must use
6116 another protocol, such as standard remote protocol. The usual
6117 sequence is something like
6119 target nrom <netrom-hostname>
6121 target remote <netrom-hostname>:1235
6125 GDB now includes support for the Apple Macintosh, as a host only. It
6126 may be run as either an MPW tool or as a standalone application, and
6127 it can debug through the serial port. All the usual GDB commands are
6128 available, but to the target command, you must supply "serial" as the
6129 device type instead of "/dev/ttyXX". See mpw-README in the main
6130 directory for more information on how to build. The MPW configuration
6131 scripts */mpw-config.in support only a few targets, and only the
6132 mips-idt-ecoff target has been tested.
6136 GDB configuration now uses autoconf. This is not user-visible,
6137 but does simplify configuration and building.
6141 GDB now supports hpux10.
6143 *** Changes in GDB-4.14:
6145 * New native configurations
6147 x86 FreeBSD i[345]86-*-freebsd
6148 x86 NetBSD i[345]86-*-netbsd
6149 NS32k NetBSD ns32k-*-netbsd
6150 Sparc NetBSD sparc-*-netbsd
6154 A29K VxWorks a29k-*-vxworks
6155 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6156 CPU32 EST-300 emulator m68*-*-est*
6157 PowerPC ELF powerpc-*-elf
6160 * Alpha OSF/1 support for procfs
6162 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6163 possible to attach to running processes. As the mounting of the /proc
6164 filesystem is optional on the Alpha, GDB automatically determines
6165 the availability of /proc during startup. This can lead to problems
6166 if /proc is unmounted after GDB has been started.
6168 * Arguments to user-defined commands
6170 User commands may accept up to 10 arguments separated by whitespace.
6171 Arguments are accessed within the user command via $arg0..$arg9. A
6174 print $arg0 + $arg1 + $arg2
6176 To execute the command use:
6179 Defines the command "adder" which prints the sum of its three arguments.
6180 Note the arguments are text substitutions, so they may reference variables,
6181 use complex expressions, or even perform inferior function calls.
6183 * New `if' and `while' commands
6185 This makes it possible to write more sophisticated user-defined
6186 commands. Both commands take a single argument, which is the
6187 expression to evaluate, and must be followed by the commands to
6188 execute, one per line, if the expression is nonzero, the list being
6189 terminated by the word `end'. The `if' command list may include an
6190 `else' word, which causes the following commands to be executed only
6191 if the expression is zero.
6193 * Fortran source language mode
6195 GDB now includes partial support for Fortran 77. It will recognize
6196 Fortran programs and can evaluate a subset of Fortran expressions, but
6197 variables and functions may not be handled correctly. GDB will work
6198 with G77, but does not yet know much about symbols emitted by other
6201 * Better HPUX support
6203 Most debugging facilities now work on dynamic executables for HPPAs
6204 running hpux9 or later. You can attach to running dynamically linked
6205 processes, but by default the dynamic libraries will be read-only, so
6206 for instance you won't be able to put breakpoints in them. To change
6207 that behavior do the following before running the program:
6213 This will cause the libraries to be mapped private and read-write.
6214 To revert to the normal behavior, do this:
6220 You cannot set breakpoints or examine data in the library until after
6221 the library is loaded if the function/data symbols do not have
6224 GDB can now also read debug symbols produced by the HP C compiler on
6225 HPPAs (sorry, no C++, Fortran or 68k support).
6227 * Target byte order now dynamically selectable
6229 You can choose which byte order to use with a target system, via the
6230 commands "set endian big" and "set endian little", and you can see the
6231 current setting by using "show endian". You can also give the command
6232 "set endian auto", in which case GDB will use the byte order
6233 associated with the executable. Currently, only embedded MIPS
6234 configurations support dynamic selection of target byte order.
6236 * New DOS host serial code
6238 This version uses DPMI interrupts to handle buffered I/O, so you
6239 no longer need to run asynctsr when debugging boards connected to
6242 *** Changes in GDB-4.13:
6244 * New "complete" command
6246 This lists all the possible completions for the rest of the line, if it
6247 were to be given as a command itself. This is intended for use by emacs.
6249 * Trailing space optional in prompt
6251 "set prompt" no longer adds a space for you after the prompt you set. This
6252 allows you to set a prompt which ends in a space or one that does not.
6254 * Breakpoint hit counts
6256 "info break" now displays a count of the number of times the breakpoint
6257 has been hit. This is especially useful in conjunction with "ignore"; you
6258 can ignore a large number of breakpoint hits, look at the breakpoint info
6259 to see how many times the breakpoint was hit, then run again, ignoring one
6260 less than that number, and this will get you quickly to the last hit of
6263 * Ability to stop printing at NULL character
6265 "set print null-stop" will cause GDB to stop printing the characters of
6266 an array when the first NULL is encountered. This is useful when large
6267 arrays actually contain only short strings.
6269 * Shared library breakpoints
6271 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6272 breakpoints in shared libraries before the executable is run.
6274 * Hardware watchpoints
6276 There is a new hardware breakpoint for the watch command for sparclite
6277 targets. See gdb/sparclite/hw_breakpoint.note.
6279 Hardware watchpoints are also now supported under GNU/Linux.
6283 Annotations have been added. These are for use with graphical interfaces,
6284 and are still experimental. Currently only gdba.el uses these.
6286 * Improved Irix 5 support
6288 GDB now works properly with Irix 5.2.
6290 * Improved HPPA support
6292 GDB now works properly with the latest GCC and GAS.
6294 * New native configurations
6296 Sequent PTX4 i[34]86-sequent-ptx4
6297 HPPA running OSF/1 hppa*-*-osf*
6298 Atari TT running SVR4 m68*-*-sysv4*
6299 RS/6000 LynxOS rs6000-*-lynxos*
6303 OS/9000 i[34]86-*-os9k
6304 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6307 * Hitachi SH7000 and E7000-PC ICE support
6309 There is now support for communicating with the Hitachi E7000-PC ICE.
6310 This is available automatically when GDB is configured for the SH.
6314 As usual, a variety of small fixes and improvements, both generic
6315 and configuration-specific. See the ChangeLog for more detail.
6317 *** Changes in GDB-4.12:
6319 * Irix 5 is now supported
6323 GDB-4.12 on the HPPA has a number of changes which make it unable
6324 to debug the output from the currently released versions of GCC and
6325 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6326 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6327 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6330 *** Changes in GDB-4.11:
6332 * User visible changes:
6336 The "set remotedebug" option is now consistent between the mips remote
6337 target, remote targets using the gdb-specific protocol, UDI (AMD's
6338 debug protocol for the 29k) and the 88k bug monitor. It is now an
6339 integer specifying a debug level (normally 0 or 1, but 2 means more
6340 debugging info for the mips target).
6342 * DEC Alpha native support
6344 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6345 debug info, but GDB works fairly well with the DEC compiler and should
6346 work with a future GCC release. See the README file for a few
6347 Alpha-specific notes.
6349 * Preliminary thread implementation
6351 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6353 * LynxOS native and target support for 386
6355 This release has been hosted on LynxOS 2.2, and also can be configured
6356 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6359 * Improvements in C++ mangling/demangling.
6361 This release has much better g++ debugging, specifically in name
6362 mangling/demangling, virtual function calls, print virtual table,
6363 call methods, ...etc.
6365 *** Changes in GDB-4.10:
6367 * User visible changes:
6369 Remote debugging using the GDB-specific (`target remote') protocol now
6370 supports the `load' command. This is only useful if you have some
6371 other way of getting the stub to the target system, and you can put it
6372 somewhere in memory where it won't get clobbered by the download.
6374 Filename completion now works.
6376 When run under emacs mode, the "info line" command now causes the
6377 arrow to point to the line specified. Also, "info line" prints
6378 addresses in symbolic form (as well as hex).
6380 All vxworks based targets now support a user settable option, called
6381 vxworks-timeout. This option represents the number of seconds gdb
6382 should wait for responses to rpc's. You might want to use this if
6383 your vxworks target is, perhaps, a slow software simulator or happens
6384 to be on the far side of a thin network line.
6388 This release contains support for using a DEC alpha as a GDB host for
6389 cross debugging. Native alpha debugging is not supported yet.
6392 *** Changes in GDB-4.9:
6396 This is the first GDB release which is accompanied by a matching testsuite.
6397 The testsuite requires installation of dejagnu, which should be available
6398 via ftp from most sites that carry GNU software.
6402 'Cfront' style demangling has had its name changed to 'ARM' style, to
6403 emphasize that it was written from the specifications in the C++ Annotated
6404 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6405 disclaimers, it still generated too much confusion with users attempting to
6406 use gdb with AT&T cfront.
6410 GDB now uses a standard remote interface to a simulator library.
6411 So far, the library contains simulators for the Zilog Z8001/2, the
6412 Hitachi H8/300, H8/500 and Super-H.
6414 * New targets supported
6416 H8/300 simulator h8300-hitachi-hms or h8300hms
6417 H8/500 simulator h8500-hitachi-hms or h8500hms
6418 SH simulator sh-hitachi-hms or sh
6419 Z8000 simulator z8k-zilog-none or z8ksim
6420 IDT MIPS board over serial line mips-idt-ecoff
6422 Cross-debugging to GO32 targets is supported. It requires a custom
6423 version of the i386-stub.c module which is integrated with the
6424 GO32 memory extender.
6426 * New remote protocols
6428 MIPS remote debugging protocol.
6430 * New source languages supported
6432 This version includes preliminary support for Chill, a Pascal like language
6433 used by telecommunications companies. Chill support is also being integrated
6434 into the GNU compiler, but we don't know when it will be publically available.
6437 *** Changes in GDB-4.8:
6439 * HP Precision Architecture supported
6441 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6442 version of this support was available as a set of patches from the
6443 University of Utah. GDB does not support debugging of programs
6444 compiled with the HP compiler, because HP will not document their file
6445 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6446 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6448 Many problems in the preliminary version have been fixed.
6450 * Faster and better demangling
6452 We have improved template demangling and fixed numerous bugs in the GNU style
6453 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6454 character types (wchar_t) are now supported. Demangling of each symbol is now
6455 only done once, and is cached when the symbol table for a file is read in.
6456 This results in a small increase in memory usage for C programs, a moderate
6457 increase in memory usage for C++ programs, and a fantastic speedup in
6460 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6461 from the specifications in the Annotated Reference Manual, which AT&T's
6462 compiler does not actually implement.
6464 * G++ multiple inheritance compiler problem
6466 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6467 inheritance lattices was reworked to properly discover ambiguities. We
6468 recently found an example which causes this new algorithm to fail in a
6469 very subtle way, producing bad debug information for those classes.
6470 The file 'gcc.patch' (in this directory) can be applied to gcc to
6471 circumvent the problem. A future GCC release will contain a complete
6474 The previous G++ debug info problem (mentioned below for the gdb-4.7
6475 release) is fixed in gcc version 2.3.2.
6477 * Improved configure script
6479 The `configure' script will now attempt to guess your system type if
6480 you don't supply a host system type. The old scheme of supplying a
6481 host system triplet is preferable over using this. All the magic is
6482 done in the new `config.guess' script. Examine it for details.
6484 We have also brought our configure script much more in line with the FSF's
6485 version. It now supports the --with-xxx options. In particular,
6486 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6487 The resulting GDB will not be able to read arbitrary object file formats --
6488 only the format ``expected'' to be used on the configured target system.
6489 We hope to make this the default in a future release.
6491 * Documentation improvements
6493 There's new internal documentation on how to modify GDB, and how to
6494 produce clean changes to the code. We implore people to read it
6495 before submitting changes.
6497 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6498 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6499 `info' files are also provided. To build `info' files from scratch,
6500 you will need the latest `makeinfo' release, which will be available in
6501 a future texinfo-X.Y release.
6503 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6504 We're not sure exactly which versions have this problem, but it has
6505 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6506 or better. If that isn't possible, there is a patch in
6507 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6508 around this problem.
6512 GDB now supports array constants that can be used in expressions typed in by
6513 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6514 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6517 The new directory `gdb/sparclite' contains a program that demonstrates
6518 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6520 * New native hosts supported
6522 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6523 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6525 * New targets supported
6527 AMD 29k family via UDI a29k-amd-udi or udi29k
6529 * New file formats supported
6531 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6532 HPUX core files, and SCO 3.2v2 core files.
6536 Attaching to processes now works again; thanks for the many bug reports.
6538 We have also stomped on a bunch of core dumps caused by
6539 printf_filtered("%s") problems.
6541 We eliminated a copyright problem on the rpc and ptrace header files
6542 for VxWorks, which was discovered at the last minute during the 4.7
6543 release. You should now be able to build a VxWorks GDB.
6545 You can now interrupt gdb while an attached process is running. This
6546 will cause the attached process to stop, and give control back to GDB.
6548 We fixed problems caused by using too many file descriptors
6549 for reading symbols from object files and libraries. This was
6550 especially a problem for programs that used many (~100) shared
6553 The `step' command now only enters a subroutine if there is line number
6554 information for the subroutine. Otherwise it acts like the `next'
6555 command. Previously, `step' would enter subroutines if there was
6556 any debugging information about the routine. This avoids problems
6557 when using `cc -g1' on MIPS machines.
6559 * Internal improvements
6561 GDB's internal interfaces have been improved to make it easier to support
6562 debugging of multiple languages in the future.
6564 GDB now uses a common structure for symbol information internally.
6565 Minimal symbols (derived from linkage symbols in object files), partial
6566 symbols (from a quick scan of debug information), and full symbols
6567 contain a common subset of information, making it easier to write
6568 shared code that handles any of them.
6570 * New command line options
6572 We now accept --silent as an alias for --quiet.
6576 The memory-mapped-malloc library is now licensed under the GNU Library
6577 General Public License.
6579 *** Changes in GDB-4.7:
6581 * Host/native/target split
6583 GDB has had some major internal surgery to untangle the support for
6584 hosts and remote targets. Now, when you configure GDB for a remote
6585 target, it will no longer load in all of the support for debugging
6586 local programs on the host. When fully completed and tested, this will
6587 ensure that arbitrary host/target combinations are possible.
6589 The primary conceptual shift is to separate the non-portable code in
6590 GDB into three categories. Host specific code is required any time GDB
6591 is compiled on that host, regardless of the target. Target specific
6592 code relates to the peculiarities of the target, but can be compiled on
6593 any host. Native specific code is everything else: it can only be
6594 built when the host and target are the same system. Child process
6595 handling and core file support are two common `native' examples.
6597 GDB's use of /proc for controlling Unix child processes is now cleaner.
6598 It has been split out into a single module under the `target_ops' vector,
6599 plus two native-dependent functions for each system that uses /proc.
6601 * New hosts supported
6603 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6604 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6605 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6607 * New targets supported
6609 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6610 68030 and CPU32 m68030-*-*, m68332-*-*
6612 * New native hosts supported
6614 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6615 (386bsd is not well tested yet)
6616 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6618 * New file formats supported
6620 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6621 supports reading of `a.out.adobe' object files, which are an a.out
6622 format extended with minimal information about multiple sections.
6626 `show copying' is the same as the old `info copying'.
6627 `show warranty' is the same as `info warrantee'.
6628 These were renamed for consistency. The old commands continue to work.
6630 `info handle' is a new alias for `info signals'.
6632 You can now define pre-command hooks, which attach arbitrary command
6633 scripts to any command. The commands in the hook will be executed
6634 prior to the user's command. You can also create a hook which will be
6635 executed whenever the program stops. See gdb.texinfo.
6639 We now deal with Cfront style name mangling, and can even extract type
6640 info from mangled symbols. GDB can automatically figure out which
6641 symbol mangling style your C++ compiler uses.
6643 Calling of methods and virtual functions has been improved as well.
6647 The crash that occured when debugging Sun Ansi-C compiled binaries is
6648 fixed. This was due to mishandling of the extra N_SO stabs output
6651 We also finally got Ultrix 4.2 running in house, and fixed core file
6652 support, with help from a dozen people on the net.
6654 John M. Farrell discovered that the reason that single-stepping was so
6655 slow on all of the Mips based platforms (primarily SGI and DEC) was
6656 that we were trying to demangle and lookup a symbol used for internal
6657 purposes on every instruction that was being stepped through. Changing
6658 the name of that symbol so that it couldn't be mistaken for a C++
6659 mangled symbol sped things up a great deal.
6661 Rich Pixley sped up symbol lookups in general by getting much smarter
6662 about when C++ symbol mangling is necessary. This should make symbol
6663 completion (TAB on the command line) much faster. It's not as fast as
6664 we'd like, but it's significantly faster than gdb-4.6.
6668 A new user controllable variable 'call_scratch_address' can
6669 specify the location of a scratch area to be used when GDB
6670 calls a function in the target. This is necessary because the
6671 usual method of putting the scratch area on the stack does not work
6672 in systems that have separate instruction and data spaces.
6674 We integrated changes to support the 29k UDI (Universal Debugger
6675 Interface), but discovered at the last minute that we didn't have all
6676 of the appropriate copyright paperwork. We are working with AMD to
6677 resolve this, and hope to have it available soon.
6681 We have sped up the remote serial line protocol, especially for targets
6682 with lots of registers. It now supports a new `expedited status' ('T')
6683 message which can be used in place of the existing 'S' status message.
6684 This allows the remote stub to send only the registers that GDB
6685 needs to make a quick decision about single-stepping or conditional
6686 breakpoints, eliminating the need to fetch the entire register set for
6687 each instruction being stepped through.
6689 The GDB remote serial protocol now implements a write-through cache for
6690 registers, only re-reading the registers if the target has run.
6692 There is also a new remote serial stub for SPARC processors. You can
6693 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6694 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6695 processor with a serial port.
6699 Configure.in files have become much easier to read and modify. A new
6700 `table driven' format makes it more obvious what configurations are
6701 supported, and what files each one uses.
6705 There is a new opcodes library which will eventually contain all of the
6706 disassembly routines and opcode tables. At present, it only contains
6707 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6708 disassembler (binutils/objdump) to share these routines.
6710 The libiberty library is now copylefted under the GNU Library General
6711 Public License. This allows more liberal use, and was done so libg++
6712 can use it. This makes no difference to GDB, since the Library License
6713 grants all the rights from the General Public License.
6717 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6718 reference to the stabs symbol info used by the debugger. It is (as far
6719 as we know) the only published document on this fascinating topic. We
6720 encourage you to read it, compare it to the stabs information on your
6721 system, and send improvements on the document in general (to
6722 bug-gdb@prep.ai.mit.edu).
6724 And, of course, many bugs have been fixed.
6727 *** Changes in GDB-4.6:
6729 * Better support for C++ function names
6731 GDB now accepts as input the "demangled form" of C++ overloaded function
6732 names and member function names, and can do command completion on such names
6733 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6734 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6735 Make use of command completion, it is your friend.
6737 GDB also now accepts a variety of C++ mangled symbol formats. They are
6738 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6739 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6740 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6741 for the list of formats.
6743 * G++ symbol mangling problem
6745 Recent versions of gcc have a bug in how they emit debugging information for
6746 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6747 directory) can be applied to gcc to fix the problem. Alternatively, if you
6748 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6749 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6750 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6753 * New 'maintenance' command
6755 All of the commands related to hacking GDB internals have been moved out of
6756 the main command set, and now live behind the 'maintenance' command. This
6757 can also be abbreviated as 'mt'. The following changes were made:
6759 dump-me -> maintenance dump-me
6760 info all-breakpoints -> maintenance info breakpoints
6761 printmsyms -> maintenance print msyms
6762 printobjfiles -> maintenance print objfiles
6763 printpsyms -> maintenance print psymbols
6764 printsyms -> maintenance print symbols
6766 The following commands are new:
6768 maintenance demangle Call internal GDB demangler routine to
6769 demangle a C++ link name and prints the result.
6770 maintenance print type Print a type chain for a given symbol
6772 * Change to .gdbinit file processing
6774 We now read the $HOME/.gdbinit file before processing the argv arguments
6775 (e.g. reading symbol files or core files). This allows global parameters to
6776 be set, which will apply during the symbol reading. The ./.gdbinit is still
6777 read after argv processing.
6779 * New hosts supported
6781 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6783 GNU/Linux support i386-unknown-linux or linux
6785 We are also including code to support the HP/PA running BSD and HPUX. This
6786 is almost guaranteed not to work, as we didn't have time to test or build it
6787 for this release. We are including it so that the more adventurous (or
6788 masochistic) of you can play with it. We also had major problems with the
6789 fact that the compiler that we got from HP doesn't support the -g option.
6792 * New targets supported
6794 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6796 * More smarts about finding #include files
6798 GDB now remembers the compilation directory for all include files, and for
6799 all files from which C is generated (like yacc and lex sources). This
6800 greatly improves GDB's ability to find yacc/lex sources, and include files,
6801 especially if you are debugging your program from a directory different from
6802 the one that contains your sources.
6804 We also fixed a bug which caused difficulty with listing and setting
6805 breakpoints in include files which contain C code. (In the past, you had to
6806 try twice in order to list an include file that you hadn't looked at before.)
6808 * Interesting infernals change
6810 GDB now deals with arbitrary numbers of sections, where the symbols for each
6811 section must be relocated relative to that section's landing place in the
6812 target's address space. This work was needed to support ELF with embedded
6813 stabs used by Solaris-2.0.
6815 * Bug fixes (of course!)
6817 There have been loads of fixes for the following things:
6818 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6819 i960, stabs, DOS(GO32), procfs, etc...
6821 See the ChangeLog for details.
6823 *** Changes in GDB-4.5:
6825 * New machines supported (host and target)
6827 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6829 SGI Irix-4.x mips-sgi-irix4 or iris4
6831 * New malloc package
6833 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6834 Mmalloc is capable of handling mutiple heaps of memory. It is also
6835 capable of saving a heap to a file, and then mapping it back in later.
6836 This can be used to greatly speedup the startup of GDB by using a
6837 pre-parsed symbol table which lives in a mmalloc managed heap. For
6838 more details, please read mmalloc/mmalloc.texi.
6842 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6843 'help info proc' for details.
6845 * MIPS ecoff symbol table format
6847 The code that reads MIPS symbol table format is now supported on all hosts.
6848 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6851 * File name changes for MS-DOS
6853 Many files in the config directories have been renamed to make it easier to
6854 support GDB on MS-DOSe systems (which have very restrictive file name
6855 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6856 environment) is close to working but has some remaining problems. Note
6857 that debugging of DOS programs is not supported, due to limitations
6858 in the ``operating system'', but it can be used to host cross-debugging.
6860 * Cross byte order fixes
6862 Many fixes have been made to support cross debugging of Sparc and MIPS
6863 targets from hosts whose byte order differs.
6865 * New -mapped and -readnow options
6867 If memory-mapped files are available on your system through the 'mmap'
6868 system call, you can use the -mapped option on the `file' or
6869 `symbol-file' commands to cause GDB to write the symbols from your
6870 program into a reusable file. If the program you are debugging is
6871 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6872 Future GDB debugging sessions will notice the presence of this file,
6873 and will quickly map in symbol information from it, rather than reading
6874 the symbol table from the executable program. Using the '-mapped'
6875 option in a GDB `file' or `symbol-file' command has the same effect as
6876 starting GDB with the '-mapped' command-line option.
6878 You can cause GDB to read the entire symbol table immediately by using
6879 the '-readnow' option with any of the commands that load symbol table
6880 information (or on the GDB command line). This makes the command
6881 slower, but makes future operations faster.
6883 The -mapped and -readnow options are typically combined in order to
6884 build a `fred.syms' file that contains complete symbol information.
6885 A simple GDB invocation to do nothing but build a `.syms' file for future
6888 gdb -batch -nx -mapped -readnow programname
6890 The `.syms' file is specific to the host machine on which GDB is run.
6891 It holds an exact image of GDB's internal symbol table. It cannot be
6892 shared across multiple host platforms.
6894 * longjmp() handling
6896 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6897 siglongjmp() without losing control. This feature has not yet been ported to
6898 all systems. It currently works on many 386 platforms, all MIPS-based
6899 platforms (SGI, DECstation, etc), and Sun3/4.
6903 Preliminary work has been put in to support the new Solaris OS from Sun. At
6904 this time, it can control and debug processes, but it is not capable of
6909 As always, many many bug fixes. The major areas were with g++, and mipsread.
6910 People using the MIPS-based platforms should experience fewer mysterious
6911 crashes and trashed symbol tables.
6913 *** Changes in GDB-4.4:
6915 * New machines supported (host and target)
6917 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6919 BSD Reno on Vax vax-dec-bsd
6920 Ultrix on Vax vax-dec-ultrix
6922 * New machines supported (target)
6924 AMD 29000 embedded, using EBMON a29k-none-none
6928 GDB continues to improve its handling of C++. `References' work better.
6929 The demangler has also been improved, and now deals with symbols mangled as
6930 per the Annotated C++ Reference Guide.
6932 GDB also now handles `stabs' symbol information embedded in MIPS
6933 `ecoff' symbol tables. Since the ecoff format was not easily
6934 extensible to handle new languages such as C++, this appeared to be a
6935 good way to put C++ debugging info into MIPS binaries. This option
6936 will be supported in the GNU C compiler, version 2, when it is
6939 * New features for SVR4
6941 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6942 shared libraries. Debugging dynamically linked programs should present
6943 only minor differences from debugging statically linked programs.
6945 The `info proc' command will print out information about any process
6946 on an SVR4 system (including the one you are debugging). At the moment,
6947 it prints the address mappings of the process.
6949 If you bring up GDB on another SVR4 system, please send mail to
6950 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6952 * Better dynamic linking support in SunOS
6954 Reading symbols from shared libraries which contain debugging symbols
6955 now works properly. However, there remain issues such as automatic
6956 skipping of `transfer vector' code during function calls, which
6957 make it harder to debug code in a shared library, than to debug the
6958 same code linked statically.
6962 GDB is now using the latest `getopt' routines from the FSF. This
6963 version accepts the -- prefix for options with long names. GDB will
6964 continue to accept the old forms (-option and +option) as well.
6965 Various single letter abbreviations for options have been explicity
6966 added to the option table so that they won't get overshadowed in the
6967 future by other options that begin with the same letter.
6971 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6972 Many assorted bugs have been handled. Many more remain to be handled.
6973 See the various ChangeLog files (primarily in gdb and bfd) for details.
6976 *** Changes in GDB-4.3:
6978 * New machines supported (host and target)
6980 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6981 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6982 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6984 * Almost SCO Unix support
6986 We had hoped to support:
6987 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6988 (except for core file support), but we discovered very late in the release
6989 that it has problems with process groups that render gdb unusable. Sorry
6990 about that. I encourage people to fix it and post the fixes.
6992 * Preliminary ELF and DWARF support
6994 GDB can read ELF object files on System V Release 4, and can handle
6995 debugging records for C, in DWARF format, in ELF files. This support
6996 is preliminary. If you bring up GDB on another SVR4 system, please
6997 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7002 GDB now uses the latest `readline' library. One user-visible change
7003 is that two tabs will list possible command completions, which previously
7004 required typing M-? (meta-question mark, or ESC ?).
7008 The `stepi' bug that many of you noticed has been squashed.
7009 Many bugs in C++ have been handled. Many more remain to be handled.
7010 See the various ChangeLog files (primarily in gdb and bfd) for details.
7012 * State of the MIPS world (in case you wondered):
7014 GDB can understand the symbol tables emitted by the compilers
7015 supplied by most vendors of MIPS-based machines, including DEC. These
7016 symbol tables are in a format that essentially nobody else uses.
7018 Some versions of gcc come with an assembler post-processor called
7019 mips-tfile. This program is required if you want to do source-level
7020 debugging of gcc-compiled programs. I believe FSF does not ship
7021 mips-tfile with gcc version 1, but it will eventually come with gcc
7024 Debugging of g++ output remains a problem. g++ version 1.xx does not
7025 really support it at all. (If you're lucky, you should be able to get
7026 line numbers and stack traces to work, but no parameters or local
7027 variables.) With some work it should be possible to improve the
7030 When gcc version 2 is released, you will have somewhat better luck.
7031 However, even then you will get confusing results for inheritance and
7034 We will eventually provide full debugging of g++ output on
7035 DECstations. This will probably involve some kind of stabs-in-ecoff
7036 encapulation, but the details have not been worked out yet.
7039 *** Changes in GDB-4.2:
7041 * Improved configuration
7043 Only one copy of `configure' exists now, and it is not self-modifying.
7044 Porting BFD is simpler.
7048 The `step' and `next' commands now only stop at the first instruction
7049 of a source line. This prevents the multiple stops that used to occur
7050 in switch statements, for-loops, etc. `Step' continues to stop if a
7051 function that has debugging information is called within the line.
7055 Lots of small bugs fixed. More remain.
7057 * New host supported (not target)
7059 Intel 386 PC clone running Mach i386-none-mach
7062 *** Changes in GDB-4.1:
7064 * Multiple source language support
7066 GDB now has internal scaffolding to handle several source languages.
7067 It determines the type of each source file from its filename extension,
7068 and will switch expression parsing and number formatting to match the
7069 language of the function in the currently selected stack frame.
7070 You can also specifically set the language to be used, with
7071 `set language c' or `set language modula-2'.
7075 GDB now has preliminary support for the GNU Modula-2 compiler,
7076 currently under development at the State University of New York at
7077 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7078 continue through the fall of 1991 and into 1992.
7080 Other Modula-2 compilers are currently not supported, and attempting to
7081 debug programs compiled with them will likely result in an error as the
7082 symbol table is read. Feel free to work on it, though!
7084 There are hooks in GDB for strict type checking and range checking,
7085 in the `Modula-2 philosophy', but they do not currently work.
7089 GDB can now write to executable and core files (e.g. patch
7090 a variable's value). You must turn this switch on, specify
7091 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7092 by assigning a new value to a variable. Modifications take
7095 * Automatic SunOS shared library reading
7097 When you run your program, GDB automatically determines where its
7098 shared libraries (if any) have been loaded, and reads their symbols.
7099 The `share' command is no longer needed. This also works when
7100 examining core files.
7104 You can specify the number of lines that the `list' command shows.
7107 * New machines supported (host and target)
7109 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7110 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7111 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7113 * New hosts supported (not targets)
7115 IBM RT/PC: romp-ibm-aix or rtpc
7117 * New targets supported (not hosts)
7119 AMD 29000 embedded with COFF a29k-none-coff
7120 AMD 29000 embedded with a.out a29k-none-aout
7121 Ultracomputer remote kernel debug a29k-nyu-kern
7123 * New remote interfaces
7129 *** Changes in GDB-4.0:
7133 Wide output is wrapped at good places to make the output more readable.
7135 Gdb now supports cross-debugging from a host machine of one type to a
7136 target machine of another type. Communication with the target system
7137 is over serial lines. The ``target'' command handles connecting to the
7138 remote system; the ``load'' command will download a program into the
7139 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7140 also supports debugging of realtime processes running under VxWorks,
7141 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7142 stub on the target system.
7144 New CPUs supported include the AMD 29000 and Intel 960.
7146 GDB now reads object files and symbol tables via a ``binary file''
7147 library, which allows a single copy of GDB to debug programs of multiple
7148 object file types such as a.out and coff.
7150 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7151 refcard.dvi and refcard.ps are available to format it).
7154 * Control-Variable user interface simplified
7156 All variables that control the operation of the debugger can be set
7157 by the ``set'' command, and displayed by the ``show'' command.
7159 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7160 ``Show prompt'' produces the response:
7161 Gdb's prompt is new-gdb=>.
7163 What follows are the NEW set commands. The command ``help set'' will
7164 print a complete list of old and new set commands. ``help set FOO''
7165 will give a longer description of the variable FOO. ``show'' will show
7166 all of the variable descriptions and their current settings.
7168 confirm on/off: Enables warning questions for operations that are
7169 hard to recover from, e.g. rerunning the program while
7170 it is already running. Default is ON.
7172 editing on/off: Enables EMACS style command line editing
7173 of input. Previous lines can be recalled with
7174 control-P, the current line can be edited with control-B,
7175 you can search for commands with control-R, etc.
7178 history filename NAME: NAME is where the gdb command history
7179 will be stored. The default is .gdb_history,
7180 or the value of the environment variable
7183 history size N: The size, in commands, of the command history. The
7184 default is 256, or the value of the environment variable
7187 history save on/off: If this value is set to ON, the history file will
7188 be saved after exiting gdb. If set to OFF, the
7189 file will not be saved. The default is OFF.
7191 history expansion on/off: If this value is set to ON, then csh-like
7192 history expansion will be performed on
7193 command line input. The default is OFF.
7195 radix N: Sets the default radix for input and output. It can be set
7196 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7197 in the current radix, so "set radix 10" is always a no-op.
7199 height N: This integer value is the number of lines on a page. Default
7200 is 24, the current `stty rows'' setting, or the ``li#''
7201 setting from the termcap entry matching the environment
7204 width N: This integer value is the number of characters on a line.
7205 Default is 80, the current `stty cols'' setting, or the ``co#''
7206 setting from the termcap entry matching the environment
7209 Note: ``set screensize'' is obsolete. Use ``set height'' and
7210 ``set width'' instead.
7212 print address on/off: Print memory addresses in various command displays,
7213 such as stack traces and structure values. Gdb looks
7214 more ``symbolic'' if you turn this off; it looks more
7215 ``machine level'' with it on. Default is ON.
7217 print array on/off: Prettyprint arrays. New convenient format! Default
7220 print demangle on/off: Print C++ symbols in "source" form if on,
7223 print asm-demangle on/off: Same, for assembler level printouts
7226 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7229 * Support for Epoch Environment.
7231 The epoch environment is a version of Emacs v18 with windowing. One
7232 new command, ``inspect'', is identical to ``print'', except that if you
7233 are running in the epoch environment, the value is printed in its own
7237 * Support for Shared Libraries
7239 GDB can now debug programs and core files that use SunOS shared libraries.
7240 Symbols from a shared library cannot be referenced
7241 before the shared library has been linked with the program (this
7242 happens after you type ``run'' and before the function main() is entered).
7243 At any time after this linking (including when examining core files
7244 from dynamically linked programs), gdb reads the symbols from each
7245 shared library when you type the ``sharedlibrary'' command.
7246 It can be abbreviated ``share''.
7248 sharedlibrary REGEXP: Load shared object library symbols for files
7249 matching a unix regular expression. No argument
7250 indicates to load symbols for all shared libraries.
7252 info sharedlibrary: Status of loaded shared libraries.
7257 A watchpoint stops execution of a program whenever the value of an
7258 expression changes. Checking for this slows down execution
7259 tremendously whenever you are in the scope of the expression, but is
7260 quite useful for catching tough ``bit-spreader'' or pointer misuse
7261 problems. Some machines such as the 386 have hardware for doing this
7262 more quickly, and future versions of gdb will use this hardware.
7264 watch EXP: Set a watchpoint (breakpoint) for an expression.
7266 info watchpoints: Information about your watchpoints.
7268 delete N: Deletes watchpoint number N (same as breakpoints).
7269 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7270 enable N: Re-enables watchpoint number N (same as breakpoints).
7273 * C++ multiple inheritance
7275 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7278 * C++ exception handling
7280 Gdb now supports limited C++ exception handling. Besides the existing
7281 ability to breakpoint on an exception handler, gdb can breakpoint on
7282 the raising of an exception (before the stack is peeled back to the
7285 catch FOO: If there is a FOO exception handler in the dynamic scope,
7286 set a breakpoint to catch exceptions which may be raised there.
7287 Multiple exceptions (``catch foo bar baz'') may be caught.
7289 info catch: Lists all exceptions which may be caught in the
7290 current stack frame.
7293 * Minor command changes
7295 The command ``call func (arg, arg, ...)'' now acts like the print
7296 command, except it does not print or save a value if the function's result
7297 is void. This is similar to dbx usage.
7299 The ``up'' and ``down'' commands now always print the frame they end up
7300 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7301 frames without printing.
7303 * New directory command
7305 'dir' now adds directories to the FRONT of the source search path.
7306 The path starts off empty. Source files that contain debug information
7307 about the directory in which they were compiled can be found even
7308 with an empty path; Sun CC and GCC include this information. If GDB can't
7309 find your source file in the current directory, type "dir .".
7311 * Configuring GDB for compilation
7313 For normal use, type ``./configure host''. See README or gdb.texinfo
7316 GDB now handles cross debugging. If you are remotely debugging between
7317 two different machines, type ``./configure host -target=targ''.
7318 Host is the machine where GDB will run; targ is the machine
7319 where the program that you are debugging will run.