1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
8 * GDB and GDBserver now support access to additional registers on
9 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
12 * GDB now has experimental support for the compilation and injection of
13 C++ source code into the inferior. This beta release does not include
14 support for several language features, such as templates, constructors,
17 This feature requires GCC 7.1 or higher built with libcp1.so
20 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
21 can be passed using the '[ADDRESS]:PORT' notation, or the regular
22 'ADDRESS:PORT' method.
24 * DWARF index cache: GDB can now automatically save indices of DWARF
25 symbols on disk to speed up further loading of the same binaries.
27 * Ada task switching is now supported on aarch64-elf targets when
28 debugging a program using the Ravenscar Profile. For more information,
29 see the "Tasking Support when using the Ravenscar Profile" section
30 in the GDB user manual.
32 * GDB in batch mode now exits with status 1 if the last command to be
35 * The RISC-V target now supports target descriptions.
37 * System call catchpoints now support system call aliases on FreeBSD.
38 When the ABI of a system call changes in FreeBSD, this is
39 implemented by leaving a compatibility system call using the old ABI
40 at the existing number and allocating a new system call number for
41 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
42 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
43 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
44 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
45 so that a system call catchpoint for the 'kevent' system call will
46 catch invocations of both the 'kevent' and 'freebsd11_kevent'
47 binaries. This ensures that 'kevent' system calls are caught for
48 binaries using either the old or new ABIs.
50 * Terminal styling is now available for the CLI and the TUI. GNU
51 Source Highlight can additionally be used to provide styling of
52 source code snippets. See the "set style" commands, below, for more
55 * Removed support for old demangling styles arm, edg, gnu, hp and
61 GNU/Linux/OpenRISC or1k*-*-linux*
65 set debug compile-cplus-types
66 show debug compile-cplus-types
67 Control the display of debug output about type conversion in the
68 C++ compile feature. Commands have no effect while compiliong
73 Control whether debug output about files/functions skipping is
76 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
77 Apply a command to some frames.
78 FLAG arguments allow to control what output to produce and how to handle
79 errors raised when applying COMMAND to a frame.
82 Apply a command to all threads (ignoring errors and empty output).
83 Shortcut for 'thread apply all -s COMMAND'.
86 Apply a command to all frames (ignoring errors and empty output).
87 Shortcut for 'frame apply all -s COMMAND'.
90 Apply a command to all frames of all threads (ignoring errors and empty
92 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
94 maint set dwarf unwinders (on|off)
95 maint show dwarf unwinders
96 Control whether DWARF unwinders can be used.
99 Display a list of open files for a process.
103 Changes to the "frame", "select-frame", and "info frame" CLI commands.
104 These commands all now take a frame specification which
105 is either a frame level, or one of the keywords 'level', 'address',
106 'function', or 'view' followed by a parameter. Selecting a frame by
107 address, or viewing a frame outside the current backtrace now
108 requires the use of a keyword. Selecting a frame by level is
109 unchanged. The MI comment "-stack-select-frame" is unchanged.
111 target remote FILENAME
112 target extended-remote FILENAME
113 If FILENAME is a Unix domain socket, GDB will attempt to connect
114 to this socket instead of opening FILENAME as a character device.
116 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
117 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
118 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
119 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
120 These commands can now print only the searched entities
121 matching the provided regexp(s), giving a condition
122 on the entity names or entity types. The flag -q disables
123 printing headers or informations messages.
129 These commands now determine the syntax for the shown entities
130 according to the language chosen by `set language'. In particular,
131 `set language auto' means to automatically choose the language of
134 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
135 The 'thread apply' command accepts new FLAG arguments.
136 FLAG arguments allow to control what output to produce and how to handle
137 errors raised when applying COMMAND to a thread.
139 set tui tab-width NCHARS
140 show tui tab-width NCHARS
141 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
143 set style enabled [on|off]
145 Enable or disable terminal styling. Styling is enabled by default
146 on most hosts, but disabled by default when in batch mode.
148 set style filename foreground COLOR
149 set style filename background COLOR
150 set style filename intensity VALUE
151 Control the styling of file names.
153 set style function foreground COLOR
154 set style function background COLOR
155 set style function intensity VALUE
156 Control the styling of function names.
158 set style variable foreground COLOR
159 set style variable background COLOR
160 set style variable intensity VALUE
161 Control the styling of variable names.
163 set style address foreground COLOR
164 set style address background COLOR
165 set style address intensity VALUE
166 Control the styling of addresses.
170 ** The '-data-disassemble' MI command now accepts an '-a' option to
171 disassemble the whole function surrounding the given program
172 counter value or function name. Support for this feature can be
173 verified by using the "-list-features" command, which should
174 contain "data-disassemble-a-option".
176 ** Command responses and notifications that include a frame now include
177 the frame's architecture in a new "arch" attribute.
179 * New native configurations
181 GNU/Linux/RISC-V riscv*-*-linux*
182 FreeBSD/riscv riscv*-*-freebsd*
186 GNU/Linux/RISC-V riscv*-*-linux*
188 CSKY GNU/LINUX csky*-*-linux
189 FreeBSD/riscv riscv*-*-freebsd*
193 ** The gdb.Inferior type has a new 'progspace' property, which is the program
194 space associated to that inferior.
196 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
197 of objfiles associated to that program space.
199 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
200 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
203 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
204 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
205 correct and did not work properly.
207 ** The gdb.Value type has a new constructor, which is used to construct a
208 gdb.Value from a Python buffer object and a gdb.Type.
214 Enable or disable the undefined behavior sanitizer. This is
215 disabled by default, but passing --enable-ubsan=yes or
216 --enable-ubsan=auto to configure will enable it. Enabling this can
217 cause a performance penalty. The undefined behavior sanitizer was
218 first introduced in GCC 4.9.
220 *** Changes in GDB 8.2
222 * The 'set disassembler-options' command now supports specifying options
225 * The 'symbol-file' command now accepts an '-o' option to add a relative
226 offset to all sections.
228 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
229 a relative offset to all sections, but it allows to override the load
230 address of individual sections using '-s'.
232 * The 'add-symbol-file' command no longer requires the second argument
233 (address of the text section).
235 * The endianness used with the 'set endian auto' mode in the absence of
236 an executable selected for debugging is now the last endianness chosen
237 either by one of the 'set endian big' and 'set endian little' commands
238 or by inferring from the last executable used, rather than the startup
241 * The pager now allows a "c" response, meaning to disable the pager
242 for the rest of the current command.
244 * The commands 'info variables/functions/types' now show the source line
245 numbers of symbol definitions when available.
247 * 'info proc' now works on running processes on FreeBSD systems and core
248 files created on FreeBSD systems.
250 * C expressions can now use _Alignof, and C++ expressions can now use
253 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
254 the vector length while the process is running.
260 Control display of debugging info regarding the FreeBSD native target.
262 set|show varsize-limit
263 This new setting allows the user to control the maximum size of Ada
264 objects being printed when those objects have a variable type,
265 instead of that maximum size being hardcoded to 65536 bytes.
267 set|show record btrace cpu
268 Controls the processor to be used for enabling errata workarounds for
271 maint check libthread-db
272 Run integrity checks on the current inferior's thread debugging
275 maint set check-libthread-db (on|off)
276 maint show check-libthread-db
277 Control whether to run integrity checks on inferior specific thread
278 debugging libraries as they are loaded. The default is not to
283 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
285 ** The commands attached to a breakpoint can be set by assigning to
286 the breakpoint's "commands" field.
288 ** gdb.execute can now execute multi-line gdb commands.
290 ** The new functions gdb.convenience_variable and
291 gdb.set_convenience_variable can be used to get and set the value
292 of convenience variables.
294 ** A gdb.Parameter will no longer print the "set" help text on an
295 ordinary "set"; instead by default a "set" will be silent unless
296 the get_set_string method returns a non-empty string.
300 RiscV ELF riscv*-*-elf
302 * Removed targets and native configurations
304 m88k running OpenBSD m88*-*-openbsd*
305 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
306 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
307 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
309 * Aarch64/Linux hardware watchpoints improvements
311 Hardware watchpoints on unaligned addresses are now properly
312 supported when running Linux kernel 4.10 or higher: read and access
313 watchpoints are no longer spuriously missed, and all watchpoints
314 lengths between 1 and 8 bytes are supported. On older kernels,
315 watchpoints set on unaligned addresses are no longer missed, with
316 the tradeoff that there is a possibility of false hits being
321 --enable-codesign=CERT
322 This can be used to invoke "codesign -s CERT" after building gdb.
323 This option is useful on macOS, where code signing is required for
324 gdb to work properly.
326 --disable-gdbcli has been removed
327 This is now silently accepted, but does nothing.
329 *** Changes in GDB 8.1
331 * GDB now supports dynamically creating arbitrary register groups specified
332 in XML target descriptions. This allows for finer grain grouping of
333 registers on systems with a large amount of registers.
335 * The 'ptype' command now accepts a '/o' flag, which prints the
336 offsets and sizes of fields in a struct, like the pahole(1) tool.
338 * New "--readnever" command line option instructs GDB to not read each
339 symbol file's symbolic debug information. This makes startup faster
340 but at the expense of not being able to perform symbolic debugging.
341 This option is intended for use cases where symbolic debugging will
342 not be used, e.g., when you only need to dump the debuggee's core.
344 * GDB now uses the GNU MPFR library, if available, to emulate target
345 floating-point arithmetic during expression evaluation when the target
346 uses different floating-point formats than the host. At least version
347 3.1 of GNU MPFR is required.
349 * GDB now supports access to the guarded-storage-control registers and the
350 software-based guarded-storage broadcast control registers on IBM z14.
352 * On Unix systems, GDB now supports transmitting environment variables
353 that are to be set or unset to GDBserver. These variables will
354 affect the environment to be passed to the remote inferior.
356 To inform GDB of environment variables that are to be transmitted to
357 GDBserver, use the "set environment" command. Only user set
358 environment variables are sent to GDBserver.
360 To inform GDB of environment variables that are to be unset before
361 the remote inferior is started by the GDBserver, use the "unset
362 environment" command.
364 * Completion improvements
366 ** GDB can now complete function parameters in linespecs and
367 explicit locations without quoting. When setting breakpoints,
368 quoting around functions names to help with TAB-completion is
369 generally no longer necessary. For example, this now completes
372 (gdb) b function(in[TAB]
373 (gdb) b function(int)
375 Related, GDB is no longer confused with completing functions in
376 C++ anonymous namespaces:
379 (gdb) b (anonymous namespace)::[TAB][TAB]
380 (anonymous namespace)::a_function()
381 (anonymous namespace)::b_function()
383 ** GDB now has much improved linespec and explicit locations TAB
384 completion support, that better understands what you're
385 completing and offers better suggestions. For example, GDB no
386 longer offers data symbols as possible completions when you're
387 setting a breakpoint.
389 ** GDB now TAB-completes label symbol names.
391 ** The "complete" command now mimics TAB completion accurately.
393 * New command line options (gcore)
396 Dump all memory mappings.
398 * Breakpoints on C++ functions are now set on all scopes by default
400 By default, breakpoints on functions/methods are now interpreted as
401 specifying all functions with the given name ignoring missing
402 leading scopes (namespaces and classes).
404 For example, assuming a C++ program with symbols named:
409 both commands "break func()" and "break B::func()" set a breakpoint
412 You can use the new flag "-qualified" to override this. This makes
413 GDB interpret the specified function name as a complete
414 fully-qualified name instead. For example, using the same C++
415 program, the "break -q B::func" command sets a breakpoint on
416 "B::func", only. A parameter has been added to the Python
417 gdb.Breakpoint constructor to achieve the same result when creating
418 a breakpoint from Python.
420 * Breakpoints on functions marked with C++ ABI tags
422 GDB can now set breakpoints on functions marked with C++ ABI tags
423 (e.g., [abi:cxx11]). See here for a description of ABI tags:
424 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
426 Functions with a C++11 abi tag are demangled/displayed like this:
428 function[abi:cxx11](int)
431 You can now set a breakpoint on such functions simply as if they had
434 (gdb) b function(int)
436 Or if you need to disambiguate between tags, like:
438 (gdb) b function[abi:other_tag](int)
440 Tab completion was adjusted accordingly as well.
444 ** New events gdb.new_inferior, gdb.inferior_deleted, and
445 gdb.new_thread are emitted. See the manual for further
446 description of these.
448 ** A new function, "gdb.rbreak" has been added to the Python API.
449 This function allows the setting of a large number of breakpoints
450 via a regex pattern in Python. See the manual for further details.
452 ** Python breakpoints can now accept explicit locations. See the
453 manual for a further description of this feature.
456 * New features in the GDB remote stub, GDBserver
458 ** GDBserver is now able to start inferior processes with a
459 specified initial working directory.
461 The user can set the desired working directory to be used from
462 GDB using the new "set cwd" command.
464 ** New "--selftest" command line option runs some GDBserver self
465 tests. These self tests are disabled in releases.
467 ** On Unix systems, GDBserver now does globbing expansion and variable
468 substitution in inferior command line arguments.
470 This is done by starting inferiors using a shell, like GDB does.
471 See "set startup-with-shell" in the user manual for how to disable
472 this from GDB when using "target extended-remote". When using
473 "target remote", you can disable the startup with shell by using the
474 new "--no-startup-with-shell" GDBserver command line option.
476 ** On Unix systems, GDBserver now supports receiving environment
477 variables that are to be set or unset from GDB. These variables
478 will affect the environment to be passed to the inferior.
480 * When catching an Ada exception raised with a message, GDB now prints
481 the message in the catchpoint hit notification. In GDB/MI mode, that
482 information is provided as an extra field named "exception-message"
483 in the *stopped notification.
485 * Trait objects can now be inspected When debugging Rust code. This
486 requires compiler support which will appear in Rust 1.24.
490 QEnvironmentHexEncoded
491 Inform GDBserver of an environment variable that is to be passed to
492 the inferior when starting it.
495 Inform GDBserver of an environment variable that is to be unset
496 before starting the remote inferior.
499 Inform GDBserver that the environment should be reset (i.e.,
500 user-set environment variables should be unset).
503 Indicates whether the inferior must be started with a shell or not.
506 Tell GDBserver that the inferior to be started should use a specific
509 * The "maintenance print c-tdesc" command now takes an optional
510 argument which is the file name of XML target description.
512 * The "maintenance selftest" command now takes an optional argument to
513 filter the tests to be run.
515 * The "enable", and "disable" commands now accept a range of
516 breakpoint locations, e.g. "enable 1.3-5".
521 Set and show the current working directory for the inferior.
524 Set and show compilation command used for compiling and injecting code
525 with the 'compile' commands.
527 set debug separate-debug-file
528 show debug separate-debug-file
529 Control the display of debug output about separate debug file search.
531 set dump-excluded-mappings
532 show dump-excluded-mappings
533 Control whether mappings marked with the VM_DONTDUMP flag should be
534 dumped when generating a core file.
537 List the registered selftests.
540 Start the debugged program stopping at the first instruction.
543 Control display of debugging messages related to OpenRISC targets.
545 set|show print type nested-type-limit
546 Set and show the limit of nesting level for nested types that the
547 type printer will show.
549 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
552 * Safer/improved support for debugging with no debug info
554 GDB no longer assumes functions with no debug information return
557 This means that GDB now refuses to call such functions unless you
558 tell it the function's type, by either casting the call to the
559 declared return type, or by casting the function to a function
560 pointer of the right type, and calling that:
562 (gdb) p getenv ("PATH")
563 'getenv' has unknown return type; cast the call to its declared return type
564 (gdb) p (char *) getenv ("PATH")
565 $1 = 0x7fffffffe "/usr/local/bin:/"...
566 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
567 $2 = 0x7fffffffe "/usr/local/bin:/"...
569 Similarly, GDB no longer assumes that global variables with no debug
570 info have type 'int', and refuses to print the variable's value
571 unless you tell it the variable's type:
574 'var' has unknown type; cast it to its declared type
578 * New native configurations
580 FreeBSD/aarch64 aarch64*-*-freebsd*
581 FreeBSD/arm arm*-*-freebsd*
585 FreeBSD/aarch64 aarch64*-*-freebsd*
586 FreeBSD/arm arm*-*-freebsd*
587 OpenRISC ELF or1k*-*-elf
589 * Removed targets and native configurations
591 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
593 *** Changes in GDB 8.0
595 * GDB now supports access to the PKU register on GNU/Linux. The register is
596 added by the Memory Protection Keys for Userspace feature which will be
597 available in future Intel CPUs.
599 * GDB now supports C++11 rvalue references.
603 ** New functions to start, stop and access a running btrace recording.
604 ** Rvalue references are now supported in gdb.Type.
606 * GDB now supports recording and replaying rdrand and rdseed Intel 64
609 * Building GDB and GDBserver now requires a C++11 compiler.
611 For example, GCC 4.8 or later.
613 It is no longer possible to build GDB or GDBserver with a C
614 compiler. The --disable-build-with-cxx configure option has been
617 * Building GDB and GDBserver now requires GNU make >= 3.81.
619 It is no longer supported to build GDB or GDBserver with another
620 implementation of the make program or an earlier version of GNU make.
622 * Native debugging on MS-Windows supports command-line redirection
624 Command-line arguments used for starting programs on MS-Windows can
625 now include redirection symbols supported by native Windows shells,
626 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
627 as "run", "start", and "set args", as well as the corresponding MI
630 * Support for thread names on MS-Windows.
632 GDB now catches and handles the special exception that programs
633 running on MS-Windows use to assign names to threads in the
636 * Support for Java programs compiled with gcj has been removed.
638 * User commands now accept an unlimited number of arguments.
639 Previously, only up to 10 was accepted.
641 * The "eval" command now expands user-defined command arguments.
643 This makes it easier to process a variable number of arguments:
648 eval "print $arg%d", $i
653 * Target descriptions can now describe registers for sparc32 and sparc64.
655 * GDB now supports DWARF version 5 (debug information format).
656 Its .debug_names index is not yet supported.
658 * New native configurations
660 FreeBSD/mips mips*-*-freebsd
664 Synopsys ARC arc*-*-elf32
665 FreeBSD/mips mips*-*-freebsd
667 * Removed targets and native configurations
669 Alpha running FreeBSD alpha*-*-freebsd*
670 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
675 Erases all the flash memory regions reported by the target.
677 maint print arc arc-instruction address
678 Print internal disassembler information about instruction at a given address.
682 set disassembler-options
683 show disassembler-options
684 Controls the passing of target specific information to the disassembler.
685 If it is necessary to specify more than one disassembler option then
686 multiple options can be placed together into a comma separated list.
687 The default value is the empty string. Currently, the only supported
688 targets are ARM, PowerPC and S/390.
693 Erases all the flash memory regions reported by the target. This is
694 equivalent to the CLI command flash-erase.
696 -file-list-shared-libraries
697 List the shared libraries in the program. This is
698 equivalent to the CLI command "info shared".
701 Catchpoints stopping the program when Ada exceptions are
702 handled. This is equivalent to the CLI command "catch handlers".
704 *** Changes in GDB 7.12
706 * GDB and GDBserver now build with a C++ compiler by default.
708 The --enable-build-with-cxx configure option is now enabled by
709 default. One must now explicitly configure with
710 --disable-build-with-cxx in order to build with a C compiler. This
711 option will be removed in a future release.
713 * GDBserver now supports recording btrace without maintaining an active
716 * GDB now supports a negative repeat count in the 'x' command to examine
717 memory backward from the given address. For example:
720 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
721 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
722 (gdb) x/-5i 0x0000000000400580
723 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
724 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
725 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
726 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
727 0x40057b <main(int, char**)+25>:
728 callq 0x400536 <Func1(int, char const*)>
730 * Fortran: Support structures with fields of dynamic types and
731 arrays of dynamic types.
733 * The symbol dumping maintenance commands have new syntax.
734 maint print symbols [-pc address] [--] [filename]
735 maint print symbols [-objfile objfile] [-source source] [--] [filename]
736 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
737 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
738 maint print msymbols [-objfile objfile] [--] [filename]
740 * GDB now supports multibit bitfields and enums in target register
743 * New Python-based convenience function $_as_string(val), which returns
744 the textual representation of a value. This function is especially
745 useful to obtain the text label of an enum value.
747 * Intel MPX bound violation handling.
749 Segmentation faults caused by a Intel MPX boundary violation
750 now display the kind of violation (upper or lower), the memory
751 address accessed and the memory bounds, along with the usual
752 signal received and code location.
756 Program received signal SIGSEGV, Segmentation fault
757 Upper bound violation while accessing address 0x7fffffffc3b3
758 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
759 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
761 * Rust language support.
762 GDB now supports debugging programs written in the Rust programming
763 language. See https://www.rust-lang.org/ for more information about
766 * Support for running interpreters on specified input/output devices
768 GDB now supports a new mechanism that allows frontends to provide
769 fully featured GDB console views, as a better alternative to
770 building such views on top of the "-interpreter-exec console"
771 command. See the new "new-ui" command below. With that command,
772 frontends can now start GDB in the traditional command-line mode
773 running in an embedded terminal emulator widget, and create a
774 separate MI interpreter running on a specified i/o device. In this
775 way, GDB handles line editing, history, tab completion, etc. in the
776 console all by itself, and the GUI uses the separate MI interpreter
777 for its own control and synchronization, invisible to the command
780 * The "catch syscall" command catches groups of related syscalls.
782 The "catch syscall" command now supports catching a group of related
783 syscalls using the 'group:' or 'g:' prefix.
788 skip -gfile file-glob-pattern
789 skip -function function
790 skip -rfunction regular-expression
791 A generalized form of the skip command, with new support for
792 glob-style file names and regular expressions for function names.
793 Additionally, a file spec and a function spec may now be combined.
795 maint info line-table REGEXP
796 Display the contents of GDB's internal line table data struture.
799 Run any GDB unit tests that were compiled in.
802 Start a new user interface instance running INTERP as interpreter,
803 using the TTY file for input/output.
807 ** gdb.Breakpoint objects have a new attribute "pending", which
808 indicates whether the breakpoint is pending.
809 ** Three new breakpoint-related events have been added:
810 gdb.breakpoint_created, gdb.breakpoint_modified, and
811 gdb.breakpoint_deleted.
814 Signal ("set") the given MS-Windows event object. This is used in
815 conjunction with the Windows JIT debugging (AeDebug) support, where
816 the OS suspends a crashing process until a debugger can attach to
817 it. Resuming the crashing process, in order to debug it, is done by
820 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
821 was added in GDBserver, including JIT compiling fast tracepoint's
822 conditional expression bytecode into native code.
824 * Support for various remote target protocols and ROM monitors has
827 target m32rsdi Remote M32R debugging over SDI
828 target mips MIPS remote debugging protocol
829 target pmon PMON ROM monitor
830 target ddb NEC's DDB variant of PMON for Vr4300
831 target rockhopper NEC RockHopper variant of PMON
832 target lsi LSI variant of PMO
834 * Support for tracepoints and fast tracepoints on powerpc-linux,
835 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
836 including JIT compiling fast tracepoint's conditional expression
837 bytecode into native code.
839 * MI async record =record-started now includes the method and format used for
840 recording. For example:
842 =record-started,thread-group="i1",method="btrace",format="bts"
844 * MI async record =thread-selected now includes the frame field. For example:
846 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
850 Andes NDS32 nds32*-*-elf
852 *** Changes in GDB 7.11
854 * GDB now supports debugging kernel-based threads on FreeBSD.
856 * Per-inferior thread numbers
858 Thread numbers are now per inferior instead of global. If you're
859 debugging multiple inferiors, GDB displays thread IDs using a
860 qualified INF_NUM.THR_NUM form. For example:
864 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
865 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
866 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
867 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
869 As consequence, thread numbers as visible in the $_thread
870 convenience variable and in Python's InferiorThread.num attribute
871 are no longer unique between inferiors.
873 GDB now maintains a second thread ID per thread, referred to as the
874 global thread ID, which is the new equivalent of thread numbers in
875 previous releases. See also $_gthread below.
877 For backwards compatibility, MI's thread IDs always refer to global
880 * Commands that accept thread IDs now accept the qualified
881 INF_NUM.THR_NUM form as well. For example:
884 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
887 * In commands that accept a list of thread IDs, you can now refer to
888 all threads of an inferior using a star wildcard. GDB accepts
889 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
890 refer to all threads of the current inferior. For example, "info
893 * You can use "info threads -gid" to display the global thread ID of
896 * The new convenience variable $_gthread holds the global number of
899 * The new convenience variable $_inferior holds the number of the
902 * GDB now displays the ID and name of the thread that hit a breakpoint
903 or received a signal, if your program is multi-threaded. For
906 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
907 Thread 1 "main" received signal SIGINT, Interrupt.
909 * Record btrace now supports non-stop mode.
911 * Support for tracepoints on aarch64-linux was added in GDBserver.
913 * The 'record instruction-history' command now indicates speculative execution
914 when using the Intel Processor Trace recording format.
916 * GDB now allows users to specify explicit locations, bypassing
917 the linespec parser. This feature is also available to GDB/MI
920 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
921 GDB now is able to debug both AArch64 applications and ARM applications
924 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
925 including JIT compiling fast tracepoint's conditional expression bytecode
928 * GDB now supports displaced stepping on AArch64 GNU/Linux.
930 * "info threads", "info inferiors", "info display", "info checkpoints"
931 and "maint info program-spaces" now list the corresponding items in
932 ascending ID order, for consistency with all other "info" commands.
934 * In Ada, the overloads selection menu has been enhanced to display the
935 parameter types and the return types for the matching overloaded subprograms.
939 maint set target-non-stop (on|off|auto)
940 maint show target-non-stop
941 Control whether GDB targets always operate in non-stop mode even if
942 "set non-stop" is "off". The default is "auto", meaning non-stop
943 mode is enabled if supported by the target.
945 maint set bfd-sharing
946 maint show bfd-sharing
947 Control the reuse of bfd objects.
951 Control display of debugging info regarding bfd caching.
955 Control display of debugging info regarding FreeBSD threads.
957 set remote multiprocess-extensions-packet
958 show remote multiprocess-extensions-packet
959 Set/show the use of the remote protocol multiprocess extensions.
961 set remote thread-events
962 show remote thread-events
963 Set/show the use of thread create/exit events.
965 set ada print-signatures on|off
966 show ada print-signatures"
967 Control whether parameter types and return types are displayed in overloads
968 selection menus. It is activaled (@code{on}) by default.
972 Controls the maximum size of memory, in bytes, that GDB will
973 allocate for value contents. Prevents incorrect programs from
974 causing GDB to allocate overly large buffers. Default is 64k.
976 * The "disassemble" command accepts a new modifier: /s.
977 It prints mixed source+disassembly like /m with two differences:
978 - disassembled instructions are now printed in program order, and
979 - and source for all relevant files is now printed.
980 The "/m" option is now considered deprecated: its "source-centric"
981 output hasn't proved useful in practice.
983 * The "record instruction-history" command accepts a new modifier: /s.
984 It behaves exactly like /m and prints mixed source+disassembly.
986 * The "set scheduler-locking" command supports a new mode "replay".
987 It behaves like "off" in record mode and like "on" in replay mode.
989 * Support for various ROM monitors has been removed:
991 target dbug dBUG ROM monitor for Motorola ColdFire
992 target picobug Motorola picobug monitor
993 target dink32 DINK32 ROM monitor for PowerPC
994 target m32r Renesas M32R/D ROM monitor
995 target mon2000 mon2000 ROM monitor
996 target ppcbug PPCBUG ROM monitor for PowerPC
998 * Support for reading/writing memory and extracting values on architectures
999 whose memory is addressable in units of any integral multiple of 8 bits.
1002 Allows to break when an Ada exception is handled.
1004 * New remote packets
1007 Indicates that an exec system call was executed.
1009 exec-events feature in qSupported
1010 The qSupported packet allows GDB to request support for exec
1011 events using the new 'gdbfeature' exec-event, and the qSupported
1012 response can contain the corresponding 'stubfeature'. Set and
1013 show commands can be used to display whether these features are enabled.
1016 Equivalent to interrupting with the ^C character, but works in
1019 thread created stop reason (T05 create:...)
1020 Indicates that the thread was just created and is stopped at entry.
1022 thread exit stop reply (w exitcode;tid)
1023 Indicates that the thread has terminated.
1026 Enables/disables thread create and exit event reporting. For
1027 example, this is used in non-stop mode when GDB stops a set of
1028 threads and synchronously waits for the their corresponding stop
1029 replies. Without exit events, if one of the threads exits, GDB
1030 would hang forever not knowing that it should no longer expect a
1031 stop for that same thread.
1034 Indicates that there are no resumed threads left in the target (all
1035 threads are stopped). The remote stub reports support for this stop
1036 reply to GDB's qSupported query.
1039 Enables/disables catching syscalls from the inferior process.
1040 The remote stub reports support for this packet to GDB's qSupported query.
1042 syscall_entry stop reason
1043 Indicates that a syscall was just called.
1045 syscall_return stop reason
1046 Indicates that a syscall just returned.
1048 * Extended-remote exec events
1050 ** GDB now has support for exec events on extended-remote Linux targets.
1051 For such targets with Linux kernels 2.5.46 and later, this enables
1052 follow-exec-mode and exec catchpoints.
1054 set remote exec-event-feature-packet
1055 show remote exec-event-feature-packet
1056 Set/show the use of the remote exec event feature.
1058 * Thread names in remote protocol
1060 The reply to qXfer:threads:read may now include a name attribute for each
1063 * Target remote mode fork and exec events
1065 ** GDB now has support for fork and exec events on target remote mode
1066 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1067 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1068 fork and exec catchpoints.
1070 * Remote syscall events
1072 ** GDB now has support for catch syscall on remote Linux targets,
1073 currently enabled on x86/x86_64 architectures.
1075 set remote catch-syscall-packet
1076 show remote catch-syscall-packet
1077 Set/show the use of the remote catch syscall feature.
1081 ** The -var-set-format command now accepts the zero-hexadecimal
1082 format. It outputs data in hexadecimal format with zero-padding on the
1087 ** gdb.InferiorThread objects have a new attribute "global_num",
1088 which refers to the thread's global thread ID. The existing
1089 "num" attribute now refers to the thread's per-inferior number.
1090 See "Per-inferior thread numbers" above.
1091 ** gdb.InferiorThread objects have a new attribute "inferior", which
1092 is the Inferior object the thread belongs to.
1094 *** Changes in GDB 7.10
1096 * Support for process record-replay and reverse debugging on aarch64*-linux*
1097 targets has been added. GDB now supports recording of A64 instruction set
1098 including advance SIMD instructions.
1100 * Support for Sun's version of the "stabs" debug file format has been removed.
1102 * GDB now honors the content of the file /proc/PID/coredump_filter
1103 (PID is the process ID) on GNU/Linux systems. This file can be used
1104 to specify the types of memory mappings that will be included in a
1105 corefile. For more information, please refer to the manual page of
1106 "core(5)". GDB also has a new command: "set use-coredump-filter
1107 on|off". It allows to set whether GDB will read the content of the
1108 /proc/PID/coredump_filter file when generating a corefile.
1110 * The "info os" command on GNU/Linux can now display information on
1112 "info os cpus" Listing of all cpus/cores on the system
1114 * GDB has two new commands: "set serial parity odd|even|none" and
1115 "show serial parity". These allows to set or show parity for the
1118 * The "info source" command now displays the producer string if it was
1119 present in the debug info. This typically includes the compiler version
1120 and may include things like its command line arguments.
1122 * The "info dll", an alias of the "info sharedlibrary" command,
1123 is now available on all platforms.
1125 * Directory names supplied to the "set sysroot" commands may be
1126 prefixed with "target:" to tell GDB to access shared libraries from
1127 the target system, be it local or remote. This replaces the prefix
1128 "remote:". The default sysroot has been changed from "" to
1129 "target:". "remote:" is automatically converted to "target:" for
1130 backward compatibility.
1132 * The system root specified by "set sysroot" will be prepended to the
1133 filename of the main executable (if reported to GDB as absolute by
1134 the operating system) when starting processes remotely, and when
1135 attaching to already-running local or remote processes.
1137 * GDB now supports automatic location and retrieval of executable
1138 files from remote targets. Remote debugging can now be initiated
1139 using only a "target remote" or "target extended-remote" command
1140 (no "set sysroot" or "file" commands are required). See "New remote
1143 * The "dump" command now supports verilog hex format.
1145 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1147 * On GNU/Linux, GDB and gdbserver are now able to access executable
1148 and shared library files without a "set sysroot" command when
1149 attaching to processes running in different mount namespaces from
1150 the debugger. This makes it possible to attach to processes in
1151 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1152 See "New remote packets" below.
1154 * The "tui reg" command now provides completion for all of the
1155 available register groups, including target specific groups.
1157 * The HISTSIZE environment variable is no longer read when determining
1158 the size of GDB's command history. GDB now instead reads the dedicated
1159 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1160 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1165 ** Memory ports can now be unbuffered.
1169 ** gdb.Objfile objects have a new attribute "username",
1170 which is the name of the objfile as specified by the user,
1171 without, for example, resolving symlinks.
1172 ** You can now write frame unwinders in Python.
1173 ** gdb.Type objects have a new method "optimized_out",
1174 returning optimized out gdb.Value instance of this type.
1175 ** gdb.Value objects have new methods "reference_value" and
1176 "const_value" which return a reference to the value and a
1177 "const" version of the value respectively.
1181 maint print symbol-cache
1182 Print the contents of the symbol cache.
1184 maint print symbol-cache-statistics
1185 Print statistics of symbol cache usage.
1187 maint flush-symbol-cache
1188 Flush the contents of the symbol cache.
1192 Start branch trace recording using Branch Trace Store (BTS) format.
1195 Evaluate expression by using the compiler and print result.
1199 Explicit commands for enabling and disabling tui mode.
1202 set mpx bound on i386 and amd64
1203 Support for bound table investigation on Intel MPX enabled applications.
1207 Start branch trace recording using Intel Processor Trace format.
1210 Print information about branch tracing internals.
1212 maint btrace packet-history
1213 Print the raw branch tracing data.
1215 maint btrace clear-packet-history
1216 Discard the stored raw branch tracing data.
1219 Discard all branch tracing data. It will be fetched and processed
1220 anew by the next "record" command.
1225 Renamed from "set debug dwarf2-die".
1226 show debug dwarf-die
1227 Renamed from "show debug dwarf2-die".
1229 set debug dwarf-read
1230 Renamed from "set debug dwarf2-read".
1231 show debug dwarf-read
1232 Renamed from "show debug dwarf2-read".
1234 maint set dwarf always-disassemble
1235 Renamed from "maint set dwarf2 always-disassemble".
1236 maint show dwarf always-disassemble
1237 Renamed from "maint show dwarf2 always-disassemble".
1239 maint set dwarf max-cache-age
1240 Renamed from "maint set dwarf2 max-cache-age".
1241 maint show dwarf max-cache-age
1242 Renamed from "maint show dwarf2 max-cache-age".
1244 set debug dwarf-line
1245 show debug dwarf-line
1246 Control display of debugging info regarding DWARF line processing.
1249 show max-completions
1250 Set the maximum number of candidates to be considered during
1251 completion. The default value is 200. This limit allows GDB
1252 to avoid generating large completion lists, the computation of
1253 which can cause the debugger to become temporarily unresponsive.
1255 set history remove-duplicates
1256 show history remove-duplicates
1257 Control the removal of duplicate history entries.
1259 maint set symbol-cache-size
1260 maint show symbol-cache-size
1261 Control the size of the symbol cache.
1263 set|show record btrace bts buffer-size
1264 Set and show the size of the ring buffer used for branch tracing in
1266 The obtained size may differ from the requested size. Use "info
1267 record" to see the obtained buffer size.
1269 set debug linux-namespaces
1270 show debug linux-namespaces
1271 Control display of debugging info regarding Linux namespaces.
1273 set|show record btrace pt buffer-size
1274 Set and show the size of the ring buffer used for branch tracing in
1275 Intel Processor Trace format.
1276 The obtained size may differ from the requested size. Use "info
1277 record" to see the obtained buffer size.
1279 maint set|show btrace pt skip-pad
1280 Set and show whether PAD packets are skipped when computing the
1283 * The command 'thread apply all' can now support new option '-ascending'
1284 to call its specified command for all threads in ascending order.
1286 * Python/Guile scripting
1288 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1289 special section named `.debug_gdb_scripts'.
1291 * New remote packets
1293 qXfer:btrace-conf:read
1294 Return the branch trace configuration for the current thread.
1296 Qbtrace-conf:bts:size
1297 Set the requested ring buffer size for branch tracing in BTS format.
1300 Enable Intel Procesor Trace-based branch tracing for the current
1301 process. The remote stub reports support for this packet to GDB's
1304 Qbtrace-conf:pt:size
1305 Set the requested ring buffer size for branch tracing in Intel Processor
1309 Indicates a memory breakpoint instruction was executed, irrespective
1310 of whether it was GDB that planted the breakpoint or the breakpoint
1311 is hardcoded in the program. This is required for correct non-stop
1315 Indicates the target stopped for a hardware breakpoint. This is
1316 required for correct non-stop mode operation.
1319 Return information about files on the remote system.
1321 qXfer:exec-file:read
1322 Return the full absolute name of the file that was executed to
1323 create a process running on the remote system.
1326 Select the filesystem on which vFile: operations with filename
1327 arguments will operate. This is required for GDB to be able to
1328 access files on remote targets where the remote stub does not
1329 share a common filesystem with the inferior(s).
1332 Indicates that a fork system call was executed.
1335 Indicates that a vfork system call was executed.
1337 vforkdone stop reason
1338 Indicates that a vfork child of the specified process has executed
1339 an exec or exit, allowing the vfork parent to resume execution.
1341 fork-events and vfork-events features in qSupported
1342 The qSupported packet allows GDB to request support for fork and
1343 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1344 and the qSupported response can contain the corresponding
1345 'stubfeatures'. Set and show commands can be used to display
1346 whether these features are enabled.
1348 * Extended-remote fork events
1350 ** GDB now has support for fork events on extended-remote Linux
1351 targets. For targets with Linux kernels 2.5.60 and later, this
1352 enables follow-fork-mode and detach-on-fork for both fork and
1353 vfork, as well as fork and vfork catchpoints.
1355 * The info record command now shows the recording format and the
1356 branch tracing configuration for the current thread when using
1357 the btrace record target.
1358 For the BTS format, it shows the ring buffer size.
1360 * GDB now has support for DTrace USDT (Userland Static Defined
1361 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1363 * GDB now supports access to vector registers on S/390 GNU/Linux
1366 * Removed command line options
1368 -xdb HP-UX XDB compatibility mode.
1370 * Removed targets and native configurations
1372 HP/PA running HP-UX hppa*-*-hpux*
1373 Itanium running HP-UX ia64-*-hpux*
1375 * New configure options
1378 This configure option allows the user to build GDB with support for
1379 Intel Processor Trace (default: auto). This requires libipt.
1381 --with-libipt-prefix=PATH
1382 Specify the path to the version of libipt that GDB should use.
1383 $PATH/include should contain the intel-pt.h header and
1384 $PATH/lib should contain the libipt.so library.
1386 *** Changes in GDB 7.9.1
1390 ** Xmethods can now specify a result type.
1392 *** Changes in GDB 7.9
1394 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1398 ** You can now access frame registers from Python scripts.
1399 ** New attribute 'producer' for gdb.Symtab objects.
1400 ** gdb.Objfile objects have a new attribute "progspace",
1401 which is the gdb.Progspace object of the containing program space.
1402 ** gdb.Objfile objects have a new attribute "owner".
1403 ** gdb.Objfile objects have a new attribute "build_id",
1404 which is the build ID generated when the file was built.
1405 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1406 ** A new event "gdb.clear_objfiles" has been added, triggered when
1407 selecting a new file to debug.
1408 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1409 ** New function gdb.lookup_objfile.
1411 New events which are triggered when GDB modifies the state of the
1414 ** gdb.events.inferior_call_pre: Function call is about to be made.
1415 ** gdb.events.inferior_call_post: Function call has just been made.
1416 ** gdb.events.memory_changed: A memory location has been altered.
1417 ** gdb.events.register_changed: A register has been altered.
1419 * New Python-based convenience functions:
1421 ** $_caller_is(name [, number_of_frames])
1422 ** $_caller_matches(regexp [, number_of_frames])
1423 ** $_any_caller_is(name [, number_of_frames])
1424 ** $_any_caller_matches(regexp [, number_of_frames])
1426 * GDB now supports the compilation and injection of source code into
1427 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1428 to compile the source code to object code, and if successful, inject
1429 and execute that code within the current context of the inferior.
1430 Currently the C language is supported. The commands used to
1431 interface with this new feature are:
1433 compile code [-raw|-r] [--] [source code]
1434 compile file [-raw|-r] filename
1438 demangle [-l language] [--] name
1439 Demangle "name" in the specified language, or the current language
1440 if elided. This command is renamed from the "maint demangle" command.
1441 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1442 as "maint demangler-warning".
1444 queue-signal signal-name-or-number
1445 Queue a signal to be delivered to the thread when it is resumed.
1447 add-auto-load-scripts-directory directory
1448 Add entries to the list of directories from which to load auto-loaded
1451 maint print user-registers
1452 List all currently available "user" registers.
1454 compile code [-r|-raw] [--] [source code]
1455 Compile, inject, and execute in the inferior the executable object
1456 code produced by compiling the provided source code.
1458 compile file [-r|-raw] filename
1459 Compile and inject into the inferior the executable object code
1460 produced by compiling the source code stored in the filename
1463 * On resume, GDB now always passes the signal the program had stopped
1464 for to the thread the signal was sent to, even if the user changed
1465 threads before resuming. Previously GDB would often (but not
1466 always) deliver the signal to the thread that happens to be current
1469 * Conversely, the "signal" command now consistently delivers the
1470 requested signal to the current thread. GDB now asks for
1471 confirmation if the program had stopped for a signal and the user
1472 switched threads meanwhile.
1474 * "breakpoint always-inserted" modes "off" and "auto" merged.
1476 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1477 won't remove breakpoints from the target until all threads stop,
1478 even in non-stop mode. The "auto" mode has been removed, and "off"
1479 is now the default mode.
1483 set debug symbol-lookup
1484 show debug symbol-lookup
1485 Control display of debugging info regarding symbol lookup.
1489 ** The -list-thread-groups command outputs an exit-code field for
1490 inferiors that have exited.
1494 MIPS SDE mips*-sde*-elf*
1498 Support for these obsolete configurations has been removed.
1500 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1501 SGI Irix-5.x mips-*-irix5*
1502 SGI Irix-6.x mips-*-irix6*
1503 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1504 VAX running Ultrix vax-*-ultrix*
1506 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1507 and "assf"), have been removed. Use the "sharedlibrary" command, or
1508 its alias "share", instead.
1510 *** Changes in GDB 7.8
1512 * New command line options
1515 This is an alias for the --data-directory option.
1517 * GDB supports printing and modifying of variable length automatic arrays
1518 as specified in ISO C99.
1520 * The ARM simulator now supports instruction level tracing
1521 with or without disassembly.
1525 GDB now has support for scripting using Guile. Whether this is
1526 available is determined at configure time.
1527 Guile version 2.0 or greater is required.
1528 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1530 * New commands (for set/show, see "New options" below)
1534 Invoke CODE by passing it to the Guile interpreter.
1538 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1540 info auto-load guile-scripts [regexp]
1541 Print the list of automatically loaded Guile scripts.
1543 * The source command is now capable of sourcing Guile scripts.
1544 This feature is dependent on the debugger being built with Guile support.
1548 set print symbol-loading (off|brief|full)
1549 show print symbol-loading
1550 Control whether to print informational messages when loading symbol
1551 information for a file. The default is "full", but when debugging
1552 programs with large numbers of shared libraries the amount of output
1553 becomes less useful.
1555 set guile print-stack (none|message|full)
1556 show guile print-stack
1557 Show a stack trace when an error is encountered in a Guile script.
1559 set auto-load guile-scripts (on|off)
1560 show auto-load guile-scripts
1561 Control auto-loading of Guile script files.
1563 maint ada set ignore-descriptive-types (on|off)
1564 maint ada show ignore-descriptive-types
1565 Control whether the debugger should ignore descriptive types in Ada
1566 programs. The default is not to ignore the descriptive types. See
1567 the user manual for more details on descriptive types and the intended
1568 usage of this option.
1570 set auto-connect-native-target
1572 Control whether GDB is allowed to automatically connect to the
1573 native target for the run, attach, etc. commands when not connected
1574 to any target yet. See also "target native" below.
1576 set record btrace replay-memory-access (read-only|read-write)
1577 show record btrace replay-memory-access
1578 Control what memory accesses are allowed during replay.
1580 maint set target-async (on|off)
1581 maint show target-async
1582 This controls whether GDB targets operate in synchronous or
1583 asynchronous mode. Normally the default is asynchronous, if it is
1584 available; but this can be changed to more easily debug problems
1585 occurring only in synchronous mode.
1587 set mi-async (on|off)
1589 Control whether MI asynchronous mode is preferred. This supersedes
1590 "set target-async" of previous GDB versions.
1592 * "set target-async" is deprecated as a CLI option and is now an alias
1593 for "set mi-async" (only puts MI into async mode).
1595 * Background execution commands (e.g., "c&", "s&", etc.) are now
1596 possible ``out of the box'' if the target supports them. Previously
1597 the user would need to explicitly enable the possibility with the
1598 "set target-async on" command.
1600 * New features in the GDB remote stub, GDBserver
1602 ** New option --debug-format=option1[,option2,...] allows one to add
1603 additional text to each output. At present only timestamps
1604 are supported: --debug-format=timestamps.
1605 Timestamps can also be turned on with the
1606 "monitor set debug-format timestamps" command from GDB.
1608 * The 'record instruction-history' command now starts counting instructions
1609 at one. This also affects the instruction ranges reported by the
1610 'record function-call-history' command when given the /i modifier.
1612 * The command 'record function-call-history' supports a new modifier '/c' to
1613 indent the function names based on their call stack depth.
1614 The fields for the '/i' and '/l' modifier have been reordered.
1615 The source line range is now prefixed with 'at'.
1616 The instruction range is now prefixed with 'inst'.
1617 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1618 "record instruction-history" and "list" commands.
1620 * The ranges given as arguments to the 'record function-call-history' and
1621 'record instruction-history' commands are now inclusive.
1623 * The btrace record target now supports the 'record goto' command.
1624 For locations inside the execution trace, the back trace is computed
1625 based on the information stored in the execution trace.
1627 * The btrace record target supports limited reverse execution and replay.
1628 The target does not record data and therefore does not allow reading
1629 memory or registers.
1631 * The "catch syscall" command now works on s390*-linux* targets.
1633 * The "compare-sections" command is no longer specific to target
1634 remote. It now works with all targets.
1636 * All native targets are now consistently called "native".
1637 Consequently, the "target child", "target GNU", "target djgpp",
1638 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1639 commands have been replaced with "target native". The QNX/NTO port
1640 leaves the "procfs" target in place and adds a "native" target for
1641 consistency with other ports. The impact on users should be minimal
1642 as these commands previously either throwed an error, or were
1643 no-ops. The target's name is visible in the output of the following
1644 commands: "help target", "info target", "info files", "maint print
1647 * The "target native" command now connects to the native target. This
1648 can be used to launch native programs even when "set
1649 auto-connect-native-target" is set to off.
1651 * GDB now supports access to Intel MPX registers on GNU/Linux.
1653 * Support for Intel AVX-512 registers on GNU/Linux.
1654 Support displaying and modifying Intel AVX-512 registers
1655 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1657 * New remote packets
1659 qXfer:btrace:read's annex
1660 The qXfer:btrace:read packet supports a new annex 'delta' to read
1661 branch trace incrementally.
1665 ** Valid Python operations on gdb.Value objects representing
1666 structs/classes invoke the corresponding overloaded operators if
1668 ** New `Xmethods' feature in the Python API. Xmethods are
1669 additional methods or replacements for existing methods of a C++
1670 class. This feature is useful for those cases where a method
1671 defined in C++ source code could be inlined or optimized out by
1672 the compiler, making it unavailable to GDB.
1675 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1677 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1678 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1679 its alias "share", instead.
1681 * The commands "set remotebaud" and "show remotebaud" are no longer
1682 supported. Use "set serial baud" and "show serial baud" (respectively)
1687 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1688 target-async". The latter is left as a deprecated alias of the
1689 former for backward compatibility. If the target supports it,
1690 CLI background execution commands are now always possible by
1691 default, independently of whether the frontend stated a
1692 preference for asynchronous execution with "-gdb-set mi-async".
1693 Previously "-gdb-set target-async off" affected both MI execution
1694 commands and CLI execution commands.
1696 *** Changes in GDB 7.7
1698 * Improved support for process record-replay and reverse debugging on
1699 arm*-linux* targets. Support for thumb32 and syscall instruction
1700 recording has been added.
1702 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1704 * GDB now supports Fission DWP file format version 2.
1705 http://gcc.gnu.org/wiki/DebugFission
1707 * New convenience function "$_isvoid", to check whether an expression
1708 is void. A void expression is an expression where the type of the
1709 result is "void". For example, some convenience variables may be
1710 "void" when evaluated (e.g., "$_exitcode" before the execution of
1711 the program being debugged; or an undefined convenience variable).
1712 Another example, when calling a function whose return type is
1715 * The "maintenance print objfiles" command now takes an optional regexp.
1717 * The "catch syscall" command now works on arm*-linux* targets.
1719 * GDB now consistently shows "<not saved>" when printing values of
1720 registers the debug info indicates have not been saved in the frame
1721 and there's nowhere to retrieve them from
1722 (callee-saved/call-clobbered registers):
1727 (gdb) info registers rax
1730 Before, the former would print "<optimized out>", and the latter
1731 "*value not available*".
1733 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1738 ** Frame filters and frame decorators have been added.
1739 ** Temporary breakpoints are now supported.
1740 ** Line tables representation has been added.
1741 ** New attribute 'parent_type' for gdb.Field objects.
1742 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1743 ** New attribute 'name' for gdb.Type objects.
1747 Nios II ELF nios2*-*-elf
1748 Nios II GNU/Linux nios2*-*-linux
1749 Texas Instruments MSP430 msp430*-*-elf
1751 * Removed native configurations
1753 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1754 been removed. ELF variants of these configurations are kept supported.
1756 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1757 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1758 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1759 i[34567]86-*-openbsd3.[0-3]
1760 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1761 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1762 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1766 Like "catch throw", but catches a re-thrown exception.
1767 maint check-psymtabs
1768 Renamed from old "maint check-symtabs".
1770 Perform consistency checks on symtabs.
1771 maint expand-symtabs
1772 Expand symtabs matching an optional regexp.
1775 Display the details of GDB configure-time options.
1777 maint set|show per-command
1778 maint set|show per-command space
1779 maint set|show per-command time
1780 maint set|show per-command symtab
1781 Enable display of per-command gdb resource usage.
1783 remove-symbol-file FILENAME
1784 remove-symbol-file -a ADDRESS
1785 Remove a symbol file added via add-symbol-file. The file to remove
1786 can be identified by its filename or by an address that lies within
1787 the boundaries of this symbol file in memory.
1790 info exceptions REGEXP
1791 Display the list of Ada exceptions defined in the program being
1792 debugged. If provided, only the exceptions whose names match REGEXP
1797 set debug symfile off|on
1799 Control display of debugging info regarding reading symbol files and
1800 symbol tables within those files
1802 set print raw frame-arguments
1803 show print raw frame-arguments
1804 Set/show whether to print frame arguments in raw mode,
1805 disregarding any defined pretty-printers.
1807 set remote trace-status-packet
1808 show remote trace-status-packet
1809 Set/show the use of remote protocol qTStatus packet.
1813 Control display of debugging messages related to Nios II targets.
1817 Control whether target-assisted range stepping is enabled.
1819 set startup-with-shell
1820 show startup-with-shell
1821 Specifies whether Unix child processes are started via a shell or
1826 Use the target memory cache for accesses to the code segment. This
1827 improves performance of remote debugging (particularly disassembly).
1829 * You can now use a literal value 'unlimited' for options that
1830 interpret 0 or -1 as meaning "unlimited". E.g., "set
1831 trace-buffer-size unlimited" is now an alias for "set
1832 trace-buffer-size -1" and "set height unlimited" is now an alias for
1835 * The "set debug symtab-create" debugging option of GDB has been changed to
1836 accept a verbosity level. 0 means "off", 1 provides basic debugging
1837 output, and values of 2 or greater provides more verbose output.
1839 * New command-line options
1841 Display the details of GDB configure-time options.
1843 * The command 'tsave' can now support new option '-ctf' to save trace
1844 buffer in Common Trace Format.
1846 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1849 * GDB now implements the the C++ 'typeid' operator.
1851 * The new convenience variable $_exception holds the exception being
1852 thrown or caught at an exception-related catchpoint.
1854 * The exception-related catchpoints, like "catch throw", now accept a
1855 regular expression which can be used to filter exceptions by type.
1857 * The new convenience variable $_exitsignal is automatically set to
1858 the terminating signal number when the program being debugged dies
1859 due to an uncaught signal.
1863 ** All MI commands now accept an optional "--language" option.
1864 Support for this feature can be verified by using the "-list-features"
1865 command, which should contain "language-option".
1867 ** The new command -info-gdb-mi-command allows the user to determine
1868 whether a GDB/MI command is supported or not.
1870 ** The "^error" result record returned when trying to execute an undefined
1871 GDB/MI command now provides a variable named "code" whose content is the
1872 "undefined-command" error code. Support for this feature can be verified
1873 by using the "-list-features" command, which should contain
1874 "undefined-command-error-code".
1876 ** The -trace-save MI command can optionally save trace buffer in Common
1879 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1881 ** The command -data-list-register-values now accepts an optional
1882 "--skip-unavailable" option. When used, only the available registers
1885 ** The new command -trace-frame-collected dumps collected variables,
1886 computed expressions, tvars, memory and registers in a traceframe.
1888 ** The commands -stack-list-locals, -stack-list-arguments and
1889 -stack-list-variables now accept an option "--skip-unavailable".
1890 When used, only the available locals or arguments are displayed.
1892 ** The -exec-run command now accepts an optional "--start" option.
1893 When used, the command follows the same semantics as the "start"
1894 command, stopping the program's execution at the start of its
1895 main subprogram. Support for this feature can be verified using
1896 the "-list-features" command, which should contain
1897 "exec-run-start-option".
1899 ** The new commands -catch-assert and -catch-exceptions insert
1900 catchpoints stopping the program when Ada exceptions are raised.
1902 ** The new command -info-ada-exceptions provides the equivalent of
1903 the new "info exceptions" command.
1905 * New system-wide configuration scripts
1906 A GDB installation now provides scripts suitable for use as system-wide
1907 configuration scripts for the following systems:
1911 * GDB now supports target-assigned range stepping with remote targets.
1912 This improves the performance of stepping source lines by reducing
1913 the number of control packets from/to GDB. See "New remote packets"
1916 * GDB now understands the element 'tvar' in the XML traceframe info.
1917 It has the id of the collected trace state variables.
1919 * On S/390 targets that provide the transactional-execution feature,
1920 the program interruption transaction diagnostic block (TDB) is now
1921 represented as a number of additional "registers" in GDB.
1923 * New remote packets
1927 The vCont packet supports a new 'r' action, that tells the remote
1928 stub to step through an address range itself, without GDB
1929 involvemement at each single-step.
1931 qXfer:libraries-svr4:read's annex
1932 The previously unused annex of the qXfer:libraries-svr4:read packet
1933 is now used to support passing an argument list. The remote stub
1934 reports support for this argument list to GDB's qSupported query.
1935 The defined arguments are "start" and "prev", used to reduce work
1936 necessary for library list updating, resulting in significant
1939 * New features in the GDB remote stub, GDBserver
1941 ** GDBserver now supports target-assisted range stepping. Currently
1942 enabled on x86/x86_64 GNU/Linux targets.
1944 ** GDBserver now adds element 'tvar' in the XML in the reply to
1945 'qXfer:traceframe-info:read'. It has the id of the collected
1946 trace state variables.
1948 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1951 * New 'z' formatter for printing and examining memory, this displays the
1952 value as hexadecimal zero padded on the left to the size of the type.
1954 * GDB can now use Windows x64 unwinding data.
1956 * The "set remotebaud" command has been replaced by "set serial baud".
1957 Similarly, "show remotebaud" has been replaced by "show serial baud".
1958 The "set remotebaud" and "show remotebaud" commands are still available
1959 to provide backward compatibility with older versions of GDB.
1961 *** Changes in GDB 7.6
1963 * Target record has been renamed to record-full.
1964 Record/replay is now enabled with the "record full" command.
1965 This also affects settings that are associated with full record/replay
1966 that have been moved from "set/show record" to "set/show record full":
1968 set|show record full insn-number-max
1969 set|show record full stop-at-limit
1970 set|show record full memory-query
1972 * A new record target "record-btrace" has been added. The new target
1973 uses hardware support to record the control-flow of a process. It
1974 does not support replaying the execution, but it implements the
1975 below new commands for investigating the recorded execution log.
1976 This new recording method can be enabled using:
1980 The "record-btrace" target is only available on Intel Atom processors
1981 and requires a Linux kernel 2.6.32 or later.
1983 * Two new commands have been added for record/replay to give information
1984 about the recorded execution without having to replay the execution.
1985 The commands are only supported by "record btrace".
1987 record instruction-history prints the execution history at
1988 instruction granularity
1990 record function-call-history prints the execution history at
1991 function granularity
1993 * New native configurations
1995 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1996 FreeBSD/powerpc powerpc*-*-freebsd
1997 x86_64/Cygwin x86_64-*-cygwin*
1998 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2002 ARM AArch64 aarch64*-*-elf
2003 ARM AArch64 GNU/Linux aarch64*-*-linux
2004 Lynx 178 PowerPC powerpc-*-lynx*178
2005 x86_64/Cygwin x86_64-*-cygwin*
2006 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2008 * If the configured location of system.gdbinit file (as given by the
2009 --with-system-gdbinit option at configure time) is in the
2010 data-directory (as specified by --with-gdb-datadir at configure
2011 time) or in one of its subdirectories, then GDB will look for the
2012 system-wide init file in the directory specified by the
2013 --data-directory command-line option.
2015 * New command line options:
2017 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2018 other initialization files, unlike -nx which disables all of them.
2020 * Removed command line options
2022 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2025 * The 'ptype' and 'whatis' commands now accept an argument to control
2028 * 'info proc' now works on some core files.
2032 ** Vectors can be created with gdb.Type.vector.
2034 ** Python's atexit.register now works in GDB.
2036 ** Types can be pretty-printed via a Python API.
2038 ** Python 3 is now supported (in addition to Python 2.4 or later)
2040 ** New class gdb.Architecture exposes GDB's internal representation
2041 of architecture in the Python API.
2043 ** New method Frame.architecture returns the gdb.Architecture object
2044 corresponding to the frame's architecture.
2046 * New Python-based convenience functions:
2048 ** $_memeq(buf1, buf2, length)
2049 ** $_streq(str1, str2)
2051 ** $_regex(str, regex)
2053 * The 'cd' command now defaults to using '~' (the home directory) if not
2056 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2057 default for GCC since November 2000.
2059 * The command 'forward-search' can now be abbreviated as 'fo'.
2061 * The command 'info tracepoints' can now display 'installed on target'
2062 or 'not installed on target' for each non-pending location of tracepoint.
2064 * New configure options
2066 --enable-libmcheck/--disable-libmcheck
2067 By default, development versions are built with -lmcheck on hosts
2068 that support it, in order to help track memory corruption issues.
2069 Release versions, on the other hand, are built without -lmcheck
2070 by default. The --enable-libmcheck/--disable-libmcheck configure
2071 options allow the user to override that default.
2072 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2073 This configure option allows the user to build GDB with
2074 libbabeltrace using which GDB can read Common Trace Format data.
2076 * New commands (for set/show, see "New options" below)
2079 Catch signals. This is similar to "handle", but allows commands and
2080 conditions to be attached.
2083 List the BFDs known to GDB.
2085 python-interactive [command]
2087 Start a Python interactive prompt, or evaluate the optional command
2088 and print the result of expressions.
2091 "py" is a new alias for "python".
2093 enable type-printer [name]...
2094 disable type-printer [name]...
2095 Enable or disable type printers.
2099 ** For the Renesas Super-H architecture, the "regs" command has been removed
2100 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2105 set print type methods (on|off)
2106 show print type methods
2107 Control whether method declarations are displayed by "ptype".
2108 The default is to show them.
2110 set print type typedefs (on|off)
2111 show print type typedefs
2112 Control whether typedef definitions are displayed by "ptype".
2113 The default is to show them.
2115 set filename-display basename|relative|absolute
2116 show filename-display
2117 Control the way in which filenames is displayed.
2118 The default is "relative", which preserves previous behavior.
2120 set trace-buffer-size
2121 show trace-buffer-size
2122 Request target to change the size of trace buffer.
2124 set remote trace-buffer-size-packet auto|on|off
2125 show remote trace-buffer-size-packet
2126 Control the use of the remote protocol `QTBuffer:size' packet.
2130 Control display of debugging messages related to ARM AArch64.
2133 set debug coff-pe-read
2134 show debug coff-pe-read
2135 Control display of debugging messages related to reading of COFF/PE
2140 Control display of debugging messages related to Mach-O symbols
2143 set debug notification
2144 show debug notification
2145 Control display of debugging info for async remote notification.
2149 ** Command parameter changes are now notified using new async record
2150 "=cmd-param-changed".
2151 ** Trace frame changes caused by command "tfind" are now notified using
2152 new async record "=traceframe-changed".
2153 ** The creation, deletion and modification of trace state variables
2154 are now notified using new async records "=tsv-created",
2155 "=tsv-deleted" and "=tsv-modified".
2156 ** The start and stop of process record are now notified using new
2157 async record "=record-started" and "=record-stopped".
2158 ** Memory changes are now notified using new async record
2160 ** The data-disassemble command response will include a "fullname" field
2161 containing the absolute file name when source has been requested.
2162 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2163 command, to allow pattern filling of memory areas.
2164 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2165 library load/unload events.
2166 ** The response to breakpoint commands and breakpoint async records
2167 includes an "installed" field containing a boolean state about each
2168 non-pending tracepoint location is whether installed on target or not.
2169 ** Output of the "-trace-status" command includes a "trace-file" field
2170 containing the name of the trace file being examined. This field is
2171 optional, and only present when examining a trace file.
2172 ** The "fullname" field is now always present along with the "file" field,
2173 even if the file cannot be found by GDB.
2175 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2176 You must have the LZMA library available when configuring GDB for this
2177 feature to be enabled. For more information, see:
2178 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2180 * New remote packets
2183 Set the size of trace buffer. The remote stub reports support for this
2184 packet to gdb's qSupported query.
2187 Enable Branch Trace Store (BTS)-based branch tracing for the current
2188 thread. The remote stub reports support for this packet to gdb's
2192 Disable branch tracing for the current thread. The remote stub reports
2193 support for this packet to gdb's qSupported query.
2196 Read the traced branches for the current thread. The remote stub
2197 reports support for this packet to gdb's qSupported query.
2199 *** Changes in GDB 7.5
2201 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2202 for more x32 ABI info.
2204 * GDB now supports access to MIPS DSP registers on Linux targets.
2206 * GDB now supports debugging microMIPS binaries.
2208 * The "info os" command on GNU/Linux can now display information on
2209 several new classes of objects managed by the operating system:
2210 "info os procgroups" lists process groups
2211 "info os files" lists file descriptors
2212 "info os sockets" lists internet-domain sockets
2213 "info os shm" lists shared-memory regions
2214 "info os semaphores" lists semaphores
2215 "info os msg" lists message queues
2216 "info os modules" lists loaded kernel modules
2218 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2219 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2220 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2221 options and inspect the probe arguments using the new $_probe_arg family
2222 of convenience variables. You can obtain more information about SystemTap
2223 in <http://sourceware.org/systemtap/>.
2225 * GDB now supports reversible debugging on ARM, it allows you to
2226 debug basic ARM and THUMB instructions, and provides
2227 record/replay support.
2229 * The option "symbol-reloading" has been deleted as it is no longer used.
2233 ** GDB commands implemented in Python can now be put in command class
2236 ** The "maint set python print-stack on|off" is now deleted.
2238 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2239 apply "flag enum"-style pretty-printing to any enum.
2241 ** gdb.lookup_symbol can now work when there is no current frame.
2243 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2244 the source at which the symbol was defined.
2246 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2247 method 'value'. The former indicates whether the symbol needs a
2248 frame in order to compute its value, and the latter computes the
2251 ** A new method 'referenced_value' on gdb.Value objects which can
2252 dereference pointer as well as C++ reference values.
2254 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2255 which return the global and static blocks (as gdb.Block objects),
2256 of the underlying symbol table, respectively.
2258 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2259 object associated with a PC value.
2261 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2262 of the address range occupied by code for the current source line.
2264 * Go language support.
2265 GDB now supports debugging programs written in the Go programming
2268 * GDBserver now supports stdio connections.
2269 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2271 * The binary "gdbtui" can no longer be built or installed.
2272 Use "gdb -tui" instead.
2274 * GDB will now print "flag" enums specially. A flag enum is one where
2275 all the enumerator values have no bits in common when pairwise
2276 "and"ed. When printing a value whose type is a flag enum, GDB will
2277 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2278 (gdb) print (enum E) 3
2281 * The filename part of a linespec will now match trailing components
2282 of a source file name. For example, "break gcc/expr.c:1000" will
2283 now set a breakpoint in build/gcc/expr.c, but not
2284 build/libcpp/expr.c.
2286 * The "info proc" and "generate-core-file" commands will now also
2287 work on remote targets connected to GDBserver on Linux.
2289 * The command "info catch" has been removed. It has been disabled
2290 since December 2007.
2292 * The "catch exception" and "catch assert" commands now accept
2293 a condition at the end of the command, much like the "break"
2294 command does. For instance:
2296 (gdb) catch exception Constraint_Error if Barrier = True
2298 Previously, it was possible to add a condition to such catchpoints,
2299 but it had to be done as a second step, after the catchpoint had been
2300 created, using the "condition" command.
2302 * The "info static-tracepoint-marker" command will now also work on
2303 native Linux targets with in-process agent.
2305 * GDB can now set breakpoints on inlined functions.
2307 * The .gdb_index section has been updated to include symbols for
2308 inlined functions. GDB will ignore older .gdb_index sections by
2309 default, which could cause symbol files to be loaded more slowly
2310 until their .gdb_index sections can be recreated. The new command
2311 "set use-deprecated-index-sections on" will cause GDB to use any older
2312 .gdb_index sections it finds. This will restore performance, but the
2313 ability to set breakpoints on inlined functions will be lost in symbol
2314 files with older .gdb_index sections.
2316 The .gdb_index section has also been updated to record more information
2317 about each symbol. This speeds up the "info variables", "info functions"
2318 and "info types" commands when used with programs having the .gdb_index
2319 section, as well as speeding up debugging with shared libraries using
2320 the .gdb_index section.
2322 * Ada support for GDB/MI Variable Objects has been added.
2324 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2329 ** New command -info-os is the MI equivalent of "info os".
2331 ** Output logs ("set logging" and related) now include MI output.
2335 ** "set use-deprecated-index-sections on|off"
2336 "show use-deprecated-index-sections on|off"
2337 Controls the use of deprecated .gdb_index sections.
2339 ** "catch load" and "catch unload" can be used to stop when a shared
2340 library is loaded or unloaded, respectively.
2342 ** "enable count" can be used to auto-disable a breakpoint after
2345 ** "info vtbl" can be used to show the virtual method tables for
2346 C++ and Java objects.
2348 ** "explore" and its sub commands "explore value" and "explore type"
2349 can be used to recursively explore values and types of
2350 expressions. These commands are available only if GDB is
2351 configured with '--with-python'.
2353 ** "info auto-load" shows status of all kinds of auto-loaded files,
2354 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2355 sequences of commands files, "info auto-load python-scripts"
2356 shows status of auto-loading Python script files,
2357 "info auto-load local-gdbinit" shows status of loading init file
2358 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2359 status of inferior specific thread debugging shared library loading.
2361 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2362 and "show auto-load-scripts" commands have been deprecated, use their
2363 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2364 and "show auto-load python-scripts" counterparts instead.
2366 ** "dprintf location,format,args..." creates a dynamic printf, which
2367 is basically a breakpoint that does a printf and immediately
2368 resumes your program's execution, so it is like a printf that you
2369 can insert dynamically at runtime instead of at compiletime.
2371 ** "set print symbol"
2373 Controls whether GDB attempts to display the symbol, if any,
2374 corresponding to addresses it prints. This defaults to "on", but
2375 you can set it to "off" to restore GDB's previous behavior.
2377 * Deprecated commands
2379 ** For the Renesas Super-H architecture, the "regs" command has been
2380 deprecated, and "info all-registers" should be used instead.
2384 Renesas RL78 rl78-*-elf
2385 HP OpenVMS ia64 ia64-hp-openvms*
2387 * GDBserver supports evaluation of breakpoint conditions. When
2388 support is advertised by GDBserver, GDB may be told to send the
2389 breakpoint conditions in bytecode form to GDBserver. GDBserver
2390 will only report the breakpoint trigger to GDB when its condition
2395 set mips compression
2396 show mips compression
2397 Select the compressed ISA encoding used in functions that have no symbol
2398 information available. The encoding can be set to either of:
2401 and is updated automatically from ELF file flags if available.
2403 set breakpoint condition-evaluation
2404 show breakpoint condition-evaluation
2405 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2406 GDBserver ("target"). Default option "auto" chooses the most efficient
2408 This option can improve debugger efficiency depending on the speed of the
2412 Disable auto-loading globally.
2415 Show auto-loading setting of all kinds of auto-loaded files.
2417 set auto-load gdb-scripts on|off
2418 show auto-load gdb-scripts
2419 Control auto-loading of GDB canned sequences of commands files.
2421 set auto-load python-scripts on|off
2422 show auto-load python-scripts
2423 Control auto-loading of Python script files.
2425 set auto-load local-gdbinit on|off
2426 show auto-load local-gdbinit
2427 Control loading of init file (.gdbinit) from current directory.
2429 set auto-load libthread-db on|off
2430 show auto-load libthread-db
2431 Control auto-loading of inferior specific thread debugging shared library.
2433 set auto-load scripts-directory <dir1>[:<dir2>...]
2434 show auto-load scripts-directory
2435 Set a list of directories from which to load auto-loaded scripts.
2436 Automatically loaded Python scripts and GDB scripts are located in one
2437 of the directories listed by this option.
2438 The delimiter (':' above) may differ according to the host platform.
2440 set auto-load safe-path <dir1>[:<dir2>...]
2441 show auto-load safe-path
2442 Set a list of directories from which it is safe to auto-load files.
2443 The delimiter (':' above) may differ according to the host platform.
2445 set debug auto-load on|off
2446 show debug auto-load
2447 Control display of debugging info for auto-loading the files above.
2449 set dprintf-style gdb|call|agent
2451 Control the way in which a dynamic printf is performed; "gdb"
2452 requests a GDB printf command, while "call" causes dprintf to call a
2453 function in the inferior. "agent" requests that the target agent
2454 (such as GDBserver) do the printing.
2456 set dprintf-function <expr>
2457 show dprintf-function
2458 set dprintf-channel <expr>
2459 show dprintf-channel
2460 Set the function and optional first argument to the call when using
2461 the "call" style of dynamic printf.
2463 set disconnected-dprintf on|off
2464 show disconnected-dprintf
2465 Control whether agent-style dynamic printfs continue to be in effect
2466 after GDB disconnects.
2468 * New configure options
2470 --with-auto-load-dir
2471 Configure default value for the 'set auto-load scripts-directory'
2472 setting above. It defaults to '$debugdir:$datadir/auto-load',
2473 $debugdir representing global debugging info directories (available
2474 via 'show debug-file-directory') and $datadir representing GDB's data
2475 directory (available via 'show data-directory').
2477 --with-auto-load-safe-path
2478 Configure default value for the 'set auto-load safe-path' setting
2479 above. It defaults to the --with-auto-load-dir setting.
2481 --without-auto-load-safe-path
2482 Set 'set auto-load safe-path' to '/', effectively disabling this
2485 * New remote packets
2487 z0/z1 conditional breakpoints extension
2489 The z0/z1 breakpoint insertion packets have been extended to carry
2490 a list of conditional expressions over to the remote stub depending on the
2491 condition evaluation mode. The use of this extension can be controlled
2492 via the "set remote conditional-breakpoints-packet" command.
2496 Specify the signals which the remote stub may pass to the debugged
2497 program without GDB involvement.
2499 * New command line options
2501 --init-command=FILE, -ix Like --command, -x but execute it
2502 before loading inferior.
2503 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2504 execute it before loading inferior.
2506 *** Changes in GDB 7.4
2508 * GDB now handles ambiguous linespecs more consistently; the existing
2509 FILE:LINE support has been expanded to other types of linespecs. A
2510 breakpoint will now be set on all matching locations in all
2511 inferiors, and locations will be added or removed according to
2514 * GDB now allows you to skip uninteresting functions and files when
2515 stepping with the "skip function" and "skip file" commands.
2517 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2518 and "show remote hardware-watchpoint-length-limit". These allows to
2519 set or show the maximum length limit (in bytes) of a remote
2520 target hardware watchpoint.
2522 This allows e.g. to use "unlimited" hardware watchpoints with the
2523 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2524 watchpoints are slower than real hardware watchpoints but are
2525 significantly faster than gdb software watchpoints.
2529 ** The register_pretty_printer function in module gdb.printing now takes
2530 an optional `replace' argument. If True, the new printer replaces any
2533 ** The "maint set python print-stack on|off" command has been
2534 deprecated and will be deleted in GDB 7.5.
2535 A new command: "set python print-stack none|full|message" has
2536 replaced it. Additionally, the default for "print-stack" is
2537 now "message", which just prints the error message without
2540 ** A prompt substitution hook (prompt_hook) is now available to the
2543 ** A new Python module, gdb.prompt has been added to the GDB Python
2544 modules library. This module provides functionality for
2545 escape sequences in prompts (used by set/show
2546 extended-prompt). These escape sequences are replaced by their
2547 corresponding value.
2549 ** Python commands and convenience-functions located in
2550 'data-directory'/python/gdb/command and
2551 'data-directory'/python/gdb/function are now automatically loaded
2554 ** Blocks now provide four new attributes. global_block and
2555 static_block will return the global and static blocks
2556 respectively. is_static and is_global are boolean attributes
2557 that indicate if the block is one of those two types.
2559 ** Symbols now provide the "type" attribute, the type of the symbol.
2561 ** The "gdb.breakpoint" function has been deprecated in favor of
2564 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2565 of a function. This class is based on the "finish" command
2566 available in the CLI.
2568 ** Type objects for struct and union types now allow access to
2569 the fields using standard Python dictionary (mapping) methods.
2570 For example, "some_type['myfield']" now works, as does
2571 "some_type.items()".
2573 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2576 ** A new function, "deep_items" has been added to the gdb.types
2577 module in the GDB Python modules library. This function returns
2578 an iterator over the fields of a struct or union type. Unlike
2579 the standard Python "iteritems" method, it will recursively traverse
2580 any anonymous fields.
2584 ** "*stopped" events can report several new "reason"s, such as
2587 ** Breakpoint changes are now notified using new async records, like
2588 "=breakpoint-modified".
2590 ** New command -ada-task-info.
2592 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2593 $sdir specifies the default system locations of shared libraries.
2594 $pdir specifies the directory where the libpthread used by the application
2597 GDB no longer looks in $sdir and $pdir after it has searched the directories
2598 mentioned in libthread-db-search-path. If you want to search those
2599 directories, they must be specified in libthread-db-search-path.
2600 The default value of libthread-db-search-path on GNU/Linux and Solaris
2601 systems is now "$sdir:$pdir".
2603 $pdir is not supported by gdbserver, it is currently ignored.
2604 $sdir is supported by gdbserver.
2606 * New configure option --with-iconv-bin.
2607 When using the internationalization support like the one in the GNU C
2608 library, GDB will invoke the "iconv" program to get a list of supported
2609 character sets. If this program lives in a non-standard location, one can
2610 use this option to specify where to find it.
2612 * When natively debugging programs on PowerPC BookE processors running
2613 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2614 watchpoints, which specify a mask in addition to an address to watch.
2615 The mask specifies that some bits of an address (the bits which are
2616 reset in the mask) should be ignored when matching the address accessed
2617 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2618 section in the user manual for more details.
2620 * The new option --once causes GDBserver to stop listening for connections once
2621 the first connection is made. The listening port used by GDBserver will
2622 become available after that.
2624 * New commands "info macros" and "alias" have been added.
2626 * New function parameters suffix @entry specifies value of function parameter
2627 at the time the function got called. Entry values are available only since
2633 "!" is now an alias of the "shell" command.
2634 Note that no space is needed between "!" and SHELL COMMAND.
2638 watch EXPRESSION mask MASK_VALUE
2639 The watch command now supports the mask argument which allows creation
2640 of masked watchpoints, if the current architecture supports this feature.
2642 info auto-load-scripts [REGEXP]
2643 This command was formerly named "maintenance print section-scripts".
2644 It is now generally useful and is no longer a maintenance-only command.
2646 info macro [-all] [--] MACRO
2647 The info macro command has new options `-all' and `--'. The first for
2648 printing all definitions of a macro. The second for explicitly specifying
2649 the end of arguments and the beginning of the macro name in case the macro
2650 name starts with a hyphen.
2652 collect[/s] EXPRESSIONS
2653 The tracepoint collect command now takes an optional modifier "/s"
2654 that directs it to dereference pointer-to-character types and
2655 collect the bytes of memory up to a zero byte. The behavior is
2656 similar to what you see when you use the regular print command on a
2657 string. An optional integer following the "/s" sets a bound on the
2658 number of bytes that will be collected.
2661 The trace start command now interprets any supplied arguments as a
2662 note to be recorded with the trace run, with an effect similar to
2663 setting the variable trace-notes.
2666 The trace stop command now interprets any arguments as a note to be
2667 mentioned along with the tstatus report that the trace was stopped
2668 with a command. The effect is similar to setting the variable
2671 * Tracepoints can now be enabled and disabled at any time after a trace
2672 experiment has been started using the standard "enable" and "disable"
2673 commands. It is now possible to start a trace experiment with no enabled
2674 tracepoints; GDB will display a warning, but will allow the experiment to
2675 begin, assuming that tracepoints will be enabled as needed while the trace
2678 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2679 locations with 4-byte instructions, when they were previously
2680 limited to locations with instructions of 5 bytes or longer.
2684 set debug dwarf2-read
2685 show debug dwarf2-read
2686 Turns on or off display of debugging messages related to reading
2687 DWARF debug info. The default is off.
2689 set debug symtab-create
2690 show debug symtab-create
2691 Turns on or off display of debugging messages related to symbol table
2692 creation. The default is off.
2695 show extended-prompt
2696 Set the GDB prompt, and allow escape sequences to be inserted to
2697 display miscellaneous information (see 'help set extended-prompt'
2698 for the list of sequences). This prompt (and any information
2699 accessed through the escape sequences) is updated every time the
2700 prompt is displayed.
2702 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2703 show print entry-values
2704 Set printing of frame argument values at function entry. In some cases
2705 GDB can determine the value of function argument which was passed by the
2706 function caller, even if the value was modified inside the called function.
2708 set debug entry-values
2709 show debug entry-values
2710 Control display of debugging info for determining frame argument values at
2711 function entry and virtual tail call frames.
2713 set basenames-may-differ
2714 show basenames-may-differ
2715 Set whether a source file may have multiple base names.
2716 (A "base name" is the name of a file with the directory part removed.
2717 Example: The base name of "/home/user/hello.c" is "hello.c".)
2718 If set, GDB will canonicalize file names (e.g., expand symlinks)
2719 before comparing them. Canonicalization is an expensive operation,
2720 but it allows the same file be known by more than one base name.
2721 If not set (the default), all source files are assumed to have just
2722 one base name, and gdb will do file name comparisons more efficiently.
2728 Set a user name and notes for the current and any future trace runs.
2729 This is useful for long-running and/or disconnected traces, to
2730 inform others (or yourself) as to who is running the trace, supply
2731 contact information, or otherwise explain what is going on.
2733 set trace-stop-notes
2734 show trace-stop-notes
2735 Set a note attached to the trace run, that is displayed when the
2736 trace has been stopped by a tstop command. This is useful for
2737 instance as an explanation, if you are stopping a trace run that was
2738 started by someone else.
2740 * New remote packets
2744 Dynamically enable a tracepoint in a started trace experiment.
2748 Dynamically disable a tracepoint in a started trace experiment.
2752 Set the user and notes of the trace run.
2756 Query the current status of a tracepoint.
2760 Query the minimum length of instruction at which a fast tracepoint may
2763 * Dcache size (number of lines) and line-size are now runtime-configurable
2764 via "set dcache line" and "set dcache line-size" commands.
2768 Texas Instruments TMS320C6x tic6x-*-*
2772 Renesas RL78 rl78-*-elf
2774 *** Changes in GDB 7.3.1
2776 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2778 *** Changes in GDB 7.3
2780 * GDB has a new command: "thread find [REGEXP]".
2781 It finds the thread id whose name, target id, or thread extra info
2782 matches the given regular expression.
2784 * The "catch syscall" command now works on mips*-linux* targets.
2786 * The -data-disassemble MI command now supports modes 2 and 3 for
2787 dumping the instruction opcodes.
2789 * New command line options
2791 -data-directory DIR Specify DIR as the "data-directory".
2792 This is mostly for testing purposes.
2794 * The "maint set python auto-load on|off" command has been renamed to
2795 "set auto-load-scripts on|off".
2797 * GDB has a new command: "set directories".
2798 It is like the "dir" command except that it replaces the
2799 source path list instead of augmenting it.
2801 * GDB now understands thread names.
2803 On GNU/Linux, "info threads" will display the thread name as set by
2804 prctl or pthread_setname_np.
2806 There is also a new command, "thread name", which can be used to
2807 assign a name internally for GDB to display.
2810 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2811 has been integrated into GDB.
2815 ** The function gdb.Write now accepts an optional keyword 'stream'.
2816 This keyword, when provided, will direct the output to either
2817 stdout, stderr, or GDB's logging output.
2819 ** Parameters can now be be sub-classed in Python, and in particular
2820 you may implement the get_set_doc and get_show_doc functions.
2821 This improves how Parameter set/show documentation is processed
2822 and allows for more dynamic content.
2824 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2825 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2826 have an is_valid method.
2828 ** Breakpoints can now be sub-classed in Python, and in particular
2829 you may implement a 'stop' function that is executed each time
2830 the inferior reaches that breakpoint.
2832 ** New function gdb.lookup_global_symbol looks up a global symbol.
2834 ** GDB values in Python are now callable if the value represents a
2835 function. For example, if 'some_value' represents a function that
2836 takes two integer parameters and returns a value, you can call
2837 that function like so:
2839 result = some_value (10,20)
2841 ** Module gdb.types has been added.
2842 It contains a collection of utilities for working with gdb.Types objects:
2843 get_basic_type, has_field, make_enum_dict.
2845 ** Module gdb.printing has been added.
2846 It contains utilities for writing and registering pretty-printers.
2847 New classes: PrettyPrinter, SubPrettyPrinter,
2848 RegexpCollectionPrettyPrinter.
2849 New function: register_pretty_printer.
2851 ** New commands "info pretty-printers", "enable pretty-printer" and
2852 "disable pretty-printer" have been added.
2854 ** gdb.parameter("directories") is now available.
2856 ** New function gdb.newest_frame returns the newest frame in the
2859 ** The gdb.InferiorThread class has a new "name" attribute. This
2860 holds the thread's name.
2862 ** Python Support for Inferior events.
2863 Python scripts can add observers to be notified of events
2864 occurring in the process being debugged.
2865 The following events are currently supported:
2866 - gdb.events.cont Continue event.
2867 - gdb.events.exited Inferior exited event.
2868 - gdb.events.stop Signal received, and Breakpoint hit events.
2872 ** GDB now puts template parameters in scope when debugging in an
2873 instantiation. For example, if you have:
2875 template<int X> int func (void) { return X; }
2877 then if you step into func<5>, "print X" will show "5". This
2878 feature requires proper debuginfo support from the compiler; it
2879 was added to GCC 4.5.
2881 ** The motion commands "next", "finish", "until", and "advance" now
2882 work better when exceptions are thrown. In particular, GDB will
2883 no longer lose control of the inferior; instead, the GDB will
2884 stop the inferior at the point at which the exception is caught.
2885 This functionality requires a change in the exception handling
2886 code that was introduced in GCC 4.5.
2888 * GDB now follows GCC's rules on accessing volatile objects when
2889 reading or writing target state during expression evaluation.
2890 One notable difference to prior behavior is that "print x = 0"
2891 no longer generates a read of x; the value of the assignment is
2892 now always taken directly from the value being assigned.
2894 * GDB now has some support for using labels in the program's source in
2895 linespecs. For instance, you can use "advance label" to continue
2896 execution to a label.
2898 * GDB now has support for reading and writing a new .gdb_index
2899 section. This section holds a fast index of DWARF debugging
2900 information and can be used to greatly speed up GDB startup and
2901 operation. See the documentation for `save gdb-index' for details.
2903 * The "watch" command now accepts an optional "-location" argument.
2904 When used, this causes GDB to watch the memory referred to by the
2905 expression. Such a watchpoint is never deleted due to it going out
2908 * GDB now supports thread debugging of core dumps on GNU/Linux.
2910 GDB now activates thread debugging using the libthread_db library
2911 when debugging GNU/Linux core dumps, similarly to when debugging
2912 live processes. As a result, when debugging a core dump file, GDB
2913 is now able to display pthread_t ids of threads. For example, "info
2914 threads" shows the same output as when debugging the process when it
2915 was live. In earlier releases, you'd see something like this:
2918 * 1 LWP 6780 main () at main.c:10
2920 While now you see this:
2923 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2925 It is also now possible to inspect TLS variables when debugging core
2928 When debugging a core dump generated on a machine other than the one
2929 used to run GDB, you may need to point GDB at the correct
2930 libthread_db library with the "set libthread-db-search-path"
2931 command. See the user manual for more details on this command.
2933 * When natively debugging programs on PowerPC BookE processors running
2934 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2935 which stop execution of the inferior whenever it executes an instruction
2936 at any address within the specified range. See the "PowerPC Embedded"
2937 section in the user manual for more details.
2939 * New features in the GDB remote stub, GDBserver
2941 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2942 and i686 LynxOS (version 5.x).
2944 ** GDBserver is now supported on Blackfin Linux.
2946 * New native configurations
2948 ia64 HP-UX ia64-*-hpux*
2952 Analog Devices, Inc. Blackfin Processor bfin-*
2954 * Ada task switching is now supported on sparc-elf targets when
2955 debugging a program using the Ravenscar Profile. For more information,
2956 see the "Tasking Support when using the Ravenscar Profile" section
2957 in the GDB user manual.
2959 * Guile support was removed.
2961 * New features in the GNU simulator
2963 ** The --map-info flag lists all known core mappings.
2965 ** CFI flashes may be simulated via the "cfi" device.
2967 *** Changes in GDB 7.2
2969 * Shared library support for remote targets by default
2971 When GDB is configured for a generic, non-OS specific target, like
2972 for example, --target=arm-eabi or one of the many *-*-elf targets,
2973 GDB now queries remote stubs for loaded shared libraries using the
2974 `qXfer:libraries:read' packet. Previously, shared library support
2975 was always disabled for such configurations.
2979 ** Argument Dependent Lookup (ADL)
2981 In C++ ADL lookup directs function search to the namespaces of its
2982 arguments even if the namespace has not been imported.
2992 Here the compiler will search for `foo' in the namespace of 'b'
2993 and find A::foo. GDB now supports this. This construct is commonly
2994 used in the Standard Template Library for operators.
2996 ** Improved User Defined Operator Support
2998 In addition to member operators, GDB now supports lookup of operators
2999 defined in a namespace and imported with a `using' directive, operators
3000 defined in the global scope, operators imported implicitly from an
3001 anonymous namespace, and the ADL operators mentioned in the previous
3003 GDB now also supports proper overload resolution for all the previously
3004 mentioned flavors of operators.
3006 ** static const class members
3008 Printing of static const class members that are initialized in the
3009 class definition has been fixed.
3011 * Windows Thread Information Block access.
3013 On Windows targets, GDB now supports displaying the Windows Thread
3014 Information Block (TIB) structure. This structure is visible either
3015 by using the new command `info w32 thread-information-block' or, by
3016 dereferencing the new convenience variable named `$_tlb', a
3017 thread-specific pointer to the TIB. This feature is also supported
3018 when remote debugging using GDBserver.
3020 * Static tracepoints
3022 Static tracepoints are calls in the user program into a tracing
3023 library. One such library is a port of the LTTng kernel tracer to
3024 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3025 When debugging with GDBserver, GDB now supports combining the GDB
3026 tracepoint machinery with such libraries. For example: the user can
3027 use GDB to probe a static tracepoint marker (a call from the user
3028 program into the tracing library) with the new "strace" command (see
3029 "New commands" below). This creates a "static tracepoint" in the
3030 breakpoint list, that can be manipulated with the same feature set
3031 as fast and regular tracepoints. E.g., collect registers, local and
3032 global variables, collect trace state variables, and define
3033 tracepoint conditions. In addition, the user can collect extra
3034 static tracepoint marker specific data, by collecting the new
3035 $_sdata internal variable. When analyzing the trace buffer, you can
3036 inspect $_sdata like any other variable available to GDB. For more
3037 information, see the "Tracepoints" chapter in GDB user manual. New
3038 remote packets have been defined to support static tracepoints, see
3039 the "New remote packets" section below.
3041 * Better reconstruction of tracepoints after disconnected tracing
3043 GDB will attempt to download the original source form of tracepoint
3044 definitions when starting a trace run, and then will upload these
3045 upon reconnection to the target, resulting in a more accurate
3046 reconstruction of the tracepoints that are in use on the target.
3050 You can now exercise direct control over the ways that GDB can
3051 affect your program. For instance, you can disallow the setting of
3052 breakpoints, so that the program can run continuously (assuming
3053 non-stop mode). In addition, the "observer" variable is available
3054 to switch all of the different controls; in observer mode, GDB
3055 cannot affect the target's behavior at all, which is useful for
3056 tasks like diagnosing live systems in the field.
3058 * The new convenience variable $_thread holds the number of the
3061 * New remote packets
3065 Return the address of the Windows Thread Information Block of a given thread.
3069 In response to several of the tracepoint packets, the target may now
3070 also respond with a number of intermediate `qRelocInsn' request
3071 packets before the final result packet, to have GDB handle
3072 relocating an instruction to execute at a different address. This
3073 is particularly useful for stubs that support fast tracepoints. GDB
3074 reports support for this feature in the qSupported packet.
3078 List static tracepoint markers in the target program.
3082 List static tracepoint markers at a given address in the target
3085 qXfer:statictrace:read
3087 Read the static trace data collected (by a `collect $_sdata'
3088 tracepoint action). The remote stub reports support for this packet
3089 to gdb's qSupported query.
3093 Send the current settings of GDB's permission flags.
3097 Send part of the source (textual) form of a tracepoint definition,
3098 which includes location, conditional, and action list.
3100 * The source command now accepts a -s option to force searching for the
3101 script in the source search path even if the script name specifies
3104 * New features in the GDB remote stub, GDBserver
3106 - GDBserver now support tracepoints (including fast tracepoints, and
3107 static tracepoints). The feature is currently supported by the
3108 i386-linux and amd64-linux builds. See the "Tracepoints support
3109 in gdbserver" section in the manual for more information.
3111 GDBserver JIT compiles the tracepoint's conditional agent
3112 expression bytecode into native code whenever possible for low
3113 overhead dynamic tracepoints conditionals. For such tracepoints,
3114 an expression that examines program state is evaluated when the
3115 tracepoint is reached, in order to determine whether to capture
3116 trace data. If the condition is simple and false, processing the
3117 tracepoint finishes very quickly and no data is gathered.
3119 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3120 for static tracepoints support.
3122 - GDBserver now supports x86_64 Windows 64-bit debugging.
3124 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3125 it understands register description.
3127 * The --batch flag now disables pagination and queries.
3129 * X86 general purpose registers
3131 GDB now supports reading/writing byte, word and double-word x86
3132 general purpose registers directly. This means you can use, say,
3133 $ah or $ax to refer, respectively, to the byte register AH and
3134 16-bit word register AX that are actually portions of the 32-bit
3135 register EAX or 64-bit register RAX.
3137 * The `commands' command now accepts a range of breakpoints to modify.
3138 A plain `commands' following a command that creates multiple
3139 breakpoints affects all the breakpoints set by that command. This
3140 applies to breakpoints set by `rbreak', and also applies when a
3141 single `break' command creates multiple breakpoints (e.g.,
3142 breakpoints on overloaded c++ functions).
3144 * The `rbreak' command now accepts a filename specification as part of
3145 its argument, limiting the functions selected by the regex to those
3146 in the specified file.
3148 * Support for remote debugging Windows and SymbianOS shared libraries
3149 from Unix hosts has been improved. Non Windows GDB builds now can
3150 understand target reported file names that follow MS-DOS based file
3151 system semantics, such as file names that include drive letters and
3152 use the backslash character as directory separator. This makes it
3153 possible to transparently use the "set sysroot" and "set
3154 solib-search-path" on Unix hosts to point as host copies of the
3155 target's shared libraries. See the new command "set
3156 target-file-system-kind" described below, and the "Commands to
3157 specify files" section in the user manual for more information.
3161 eval template, expressions...
3162 Convert the values of one or more expressions under the control
3163 of the string template to a command line, and call it.
3165 set target-file-system-kind unix|dos-based|auto
3166 show target-file-system-kind
3167 Set or show the assumed file system kind for target reported file
3170 save breakpoints <filename>
3171 Save all current breakpoint definitions to a file suitable for use
3172 in a later debugging session. To read the saved breakpoint
3173 definitions, use the `source' command.
3175 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3178 info static-tracepoint-markers
3179 Display information about static tracepoint markers in the target.
3181 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3182 Define a static tracepoint by probing a marker at the given
3183 function, line, address, or marker ID.
3187 Enable and disable observer mode.
3189 set may-write-registers on|off
3190 set may-write-memory on|off
3191 set may-insert-breakpoints on|off
3192 set may-insert-tracepoints on|off
3193 set may-insert-fast-tracepoints on|off
3194 set may-interrupt on|off
3195 Set individual permissions for GDB effects on the target. Note that
3196 some of these settings can have undesirable or surprising
3197 consequences, particularly when changed in the middle of a session.
3198 For instance, disabling the writing of memory can prevent
3199 breakpoints from being inserted, cause single-stepping to fail, or
3200 even crash your program, if you disable after breakpoints have been
3201 inserted. However, GDB should not crash.
3203 set record memory-query on|off
3204 show record memory-query
3205 Control whether to stop the inferior if memory changes caused
3206 by an instruction cannot be recorded.
3211 The disassemble command now supports "start,+length" form of two arguments.
3215 ** GDB now provides a new directory location, called the python directory,
3216 where Python scripts written for GDB can be installed. The location
3217 of that directory is <data-directory>/python, where <data-directory>
3218 is the GDB data directory. For more details, see section `Scripting
3219 GDB using Python' in the manual.
3221 ** The GDB Python API now has access to breakpoints, symbols, symbol
3222 tables, program spaces, inferiors, threads and frame's code blocks.
3223 Additionally, GDB Parameters can now be created from the API, and
3224 manipulated via set/show in the CLI.
3226 ** New functions gdb.target_charset, gdb.target_wide_charset,
3227 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3229 ** New exception gdb.GdbError.
3231 ** Pretty-printers are now also looked up in the current program space.
3233 ** Pretty-printers can now be individually enabled and disabled.
3235 ** GDB now looks for names of Python scripts to auto-load in a
3236 special section named `.debug_gdb_scripts', in addition to looking
3237 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3239 * Tracepoint actions were unified with breakpoint commands. In particular,
3240 there are no longer differences in "info break" output for breakpoints and
3241 tracepoints and the "commands" command can be used for both tracepoints and
3242 regular breakpoints.
3246 ARM Symbian arm*-*-symbianelf*
3248 * D language support.
3249 GDB now supports debugging programs written in the D programming
3252 * GDB now supports the extended ptrace interface for PowerPC which is
3253 available since Linux kernel version 2.6.34. This automatically enables
3254 any hardware breakpoints and additional hardware watchpoints available in
3255 the processor. The old ptrace interface exposes just one hardware
3256 watchpoint and no hardware breakpoints.
3258 * GDB is now able to use the Data Value Compare (DVC) register available on
3259 embedded PowerPC processors to implement in hardware simple watchpoint
3260 conditions of the form:
3262 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3264 This works in native GDB running on Linux kernels with the extended ptrace
3265 interface mentioned above.
3267 *** Changes in GDB 7.1
3271 ** Namespace Support
3273 GDB now supports importing of namespaces in C++. This enables the
3274 user to inspect variables from imported namespaces. Support for
3275 namepace aliasing has also been added. So, if a namespace is
3276 aliased in the current scope (e.g. namepace C=A; ) the user can
3277 print variables using the alias (e.g. (gdb) print C::x).
3281 All known bugs relating to the printing of virtual base class were
3282 fixed. It is now possible to call overloaded static methods using a
3287 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3288 and reinterpret_cast<> are now handled by the C++ expression parser.
3292 Xilinx MicroBlaze microblaze-*-*
3297 Xilinx MicroBlaze microblaze
3300 * Multi-program debugging.
3302 GDB now has support for multi-program (a.k.a. multi-executable or
3303 multi-exec) debugging. This allows for debugging multiple inferiors
3304 simultaneously each running a different program under the same GDB
3305 session. See "Debugging Multiple Inferiors and Programs" in the
3306 manual for more information. This implied some user visible changes
3307 in the multi-inferior support. For example, "info inferiors" now
3308 lists inferiors that are not running yet or that have exited
3309 already. See also "New commands" and "New options" below.
3311 * New tracing features
3313 GDB's tracepoint facility now includes several new features:
3315 ** Trace state variables
3317 GDB tracepoints now include support for trace state variables, which
3318 are variables managed by the target agent during a tracing
3319 experiment. They are useful for tracepoints that trigger each
3320 other, so for instance one tracepoint can count hits in a variable,
3321 and then a second tracepoint has a condition that is true when the
3322 count reaches a particular value. Trace state variables share the
3323 $-syntax of GDB convenience variables, and can appear in both
3324 tracepoint actions and condition expressions. Use the "tvariable"
3325 command to create, and "info tvariables" to view; see "Trace State
3326 Variables" in the manual for more detail.
3330 GDB now includes an option for defining fast tracepoints, which
3331 targets may implement more efficiently, such as by installing a jump
3332 into the target agent rather than a trap instruction. The resulting
3333 speedup can be by two orders of magnitude or more, although the
3334 tradeoff is that some program locations on some target architectures
3335 might not allow fast tracepoint installation, for instance if the
3336 instruction to be replaced is shorter than the jump. To request a
3337 fast tracepoint, use the "ftrace" command, with syntax identical to
3338 the regular trace command.
3340 ** Disconnected tracing
3342 It is now possible to detach GDB from the target while it is running
3343 a trace experiment, then reconnect later to see how the experiment
3344 is going. In addition, a new variable disconnected-tracing lets you
3345 tell the target agent whether to continue running a trace if the
3346 connection is lost unexpectedly.
3350 GDB now has the ability to save the trace buffer into a file, and
3351 then use that file as a target, similarly to you can do with
3352 corefiles. You can select trace frames, print data that was
3353 collected in them, and use tstatus to display the state of the
3354 tracing run at the moment that it was saved. To create a trace
3355 file, use "tsave <filename>", and to use it, do "target tfile
3358 ** Circular trace buffer
3360 You can ask the target agent to handle the trace buffer as a
3361 circular buffer, discarding the oldest trace frames to make room for
3362 newer ones, by setting circular-trace-buffer to on. This feature may
3363 not be available for all target agents.
3368 The disassemble command, when invoked with two arguments, now requires
3369 the arguments to be comma-separated.
3372 The info variables command now displays variable definitions. Files
3373 which only declare a variable are not shown.
3376 The source command is now capable of sourcing Python scripts.
3377 This feature is dependent on the debugger being build with Python
3380 Related to this enhancement is also the introduction of a new command
3381 "set script-extension" (see below).
3383 * New commands (for set/show, see "New options" below)
3385 record save [<FILENAME>]
3386 Save a file (in core file format) containing the process record
3387 execution log for replay debugging at a later time.
3389 record restore <FILENAME>
3390 Restore the process record execution log that was saved at an
3391 earlier time, for replay debugging.
3393 add-inferior [-copies <N>] [-exec <FILENAME>]
3396 clone-inferior [-copies <N>] [ID]
3397 Make a new inferior ready to execute the same program another
3398 inferior has loaded.
3403 maint info program-spaces
3404 List the program spaces loaded into GDB.
3406 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3407 show remote interrupt-sequence
3408 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3409 as the sequence to the remote target in order to interrupt the execution.
3410 Ctrl-C is a default. Some system prefers BREAK which is high level of
3411 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3412 Magic SysRq g. It is BREAK signal and character 'g'.
3414 set remote interrupt-on-connect [on | off]
3415 show remote interrupt-on-connect
3416 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3417 remote target when gdb connects to it. This is needed when you debug
3420 set remotebreak [on | off]
3422 Deprecated. Use "set/show remote interrupt-sequence" instead.
3424 tvariable $NAME [ = EXP ]
3425 Create or modify a trace state variable.
3428 List trace state variables and their values.
3430 delete tvariable $NAME ...
3431 Delete one or more trace state variables.
3434 Evaluate the given expressions without collecting anything into the
3435 trace buffer. (Valid in tracepoint actions only.)
3437 ftrace FN / FILE:LINE / *ADDR
3438 Define a fast tracepoint at the given function, line, or address.
3440 * New expression syntax
3442 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3443 GDB now parses 0b101010 identically with 42.
3447 set follow-exec-mode new|same
3448 show follow-exec-mode
3449 Control whether GDB reuses the same inferior across an exec call or
3450 creates a new one. This is useful to be able to restart the old
3451 executable after the inferior having done an exec call.
3453 set default-collect EXPR, ...
3454 show default-collect
3455 Define a list of expressions to be collected at each tracepoint.
3456 This is a useful way to ensure essential items are not overlooked,
3457 such as registers or a critical global variable.
3459 set disconnected-tracing
3460 show disconnected-tracing
3461 If set to 1, the target is instructed to continue tracing if it
3462 loses its connection to GDB. If 0, the target is to stop tracing
3465 set circular-trace-buffer
3466 show circular-trace-buffer
3467 If set to on, the target is instructed to use a circular trace buffer
3468 and discard the oldest trace frames instead of stopping the trace due
3469 to a full trace buffer. If set to off, the trace stops when the buffer
3470 fills up. Some targets may not support this.
3472 set script-extension off|soft|strict
3473 show script-extension
3474 If set to "off", the debugger does not perform any script language
3475 recognition, and all sourced files are assumed to be GDB scripts.
3476 If set to "soft" (the default), files are sourced according to
3477 filename extension, falling back to GDB scripts if the first
3479 If set to "strict", files are sourced according to filename extension.
3481 set ada trust-PAD-over-XVS on|off
3482 show ada trust-PAD-over-XVS
3483 If off, activate a workaround against a bug in the debugging information
3484 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3485 the GCC sources for more information about the GNAT encoding and
3486 PAD types in particular). It is always safe to set this option to
3487 off, but this introduces a slight performance penalty. The default
3490 * Python API Improvements
3492 ** GDB provides the new class gdb.LazyString. This is useful in
3493 some pretty-printing cases. The new method gdb.Value.lazy_string
3494 provides a simple way to create objects of this type.
3496 ** The fields returned by gdb.Type.fields now have an
3497 `is_base_class' attribute.
3499 ** The new method gdb.Type.range returns the range of an array type.
3501 ** The new method gdb.parse_and_eval can be used to parse and
3502 evaluate an expression.
3504 * New remote packets
3507 Define a trace state variable.
3510 Get the current value of a trace state variable.
3513 Set desired tracing behavior upon disconnection.
3516 Set the trace buffer to be linear or circular.
3519 Get data about the tracepoints currently in use.
3523 Process record now works correctly with hardware watchpoints.
3525 Multiple bug fixes have been made to the mips-irix port, making it
3526 much more reliable. In particular:
3527 - Debugging threaded applications is now possible again. Previously,
3528 GDB would hang while starting the program, or while waiting for
3529 the program to stop at a breakpoint.
3530 - Attaching to a running process no longer hangs.
3531 - An error occurring while loading a core file has been fixed.
3532 - Changing the value of the PC register now works again. This fixes
3533 problems observed when using the "jump" command, or when calling
3534 a function from GDB, or even when assigning a new value to $pc.
3535 - With the "finish" and "return" commands, the return value for functions
3536 returning a small array is now correctly printed.
3537 - It is now possible to break on shared library code which gets executed
3538 during a shared library init phase (code executed while executing
3539 their .init section). Previously, the breakpoint would have no effect.
3540 - GDB is now able to backtrace through the signal handler for
3541 non-threaded programs.
3543 PIE (Position Independent Executable) programs debugging is now supported.
3544 This includes debugging execution of PIC (Position Independent Code) shared
3545 libraries although for that, it should be possible to run such libraries as an
3548 *** Changes in GDB 7.0
3550 * GDB now has an interface for JIT compilation. Applications that
3551 dynamically generate code can create symbol files in memory and register
3552 them with GDB. For users, the feature should work transparently, and
3553 for JIT developers, the interface is documented in the GDB manual in the
3554 "JIT Compilation Interface" chapter.
3556 * Tracepoints may now be conditional. The syntax is as for
3557 breakpoints; either an "if" clause appended to the "trace" command,
3558 or the "condition" command is available. GDB sends the condition to
3559 the target for evaluation using the same bytecode format as is used
3560 for tracepoint actions.
3562 * The disassemble command now supports: an optional /r modifier, print the
3563 raw instructions in hex as well as in symbolic form, and an optional /m
3564 modifier to print mixed source+assembly.
3566 * Process record and replay
3568 In a architecture environment that supports ``process record and
3569 replay'', ``process record and replay'' target can record a log of
3570 the process execution, and replay it with both forward and reverse
3573 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3574 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3575 set execution-direction {forward|reverse}, for targets that support
3578 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3579 feature is available with a native GDB running on kernel version
3582 * GDB now has support for multi-byte and wide character sets on the
3583 target. Strings whose character type is wchar_t, char16_t, or
3584 char32_t are now correctly printed. GDB supports wide- and unicode-
3585 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3586 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3587 `printf'. This feature requires iconv to work properly; if your
3588 system does not have a working iconv, GDB can use GNU libiconv. See
3589 the installation instructions for more information.
3591 * GDB now supports automatic retrieval of shared library files from
3592 remote targets. To use this feature, specify a system root that begins
3593 with the `remote:' prefix, either via the `set sysroot' command or via
3594 the `--with-sysroot' configure-time option.
3596 * "info sharedlibrary" now takes an optional regex of libraries to show,
3597 and it now reports if a shared library has no debugging information.
3599 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3600 now complete on file names.
3602 * When completing in expressions, gdb will attempt to limit
3603 completions to allowable structure or union fields, where appropriate.
3604 For instance, consider:
3606 # struct example { int f1; double f2; };
3607 # struct example variable;
3610 If the user types TAB at the end of this command line, the available
3611 completions will be "f1" and "f2".
3613 * Inlined functions are now supported. They show up in backtraces, and
3614 the "step", "next", and "finish" commands handle them automatically.
3616 * GDB now supports the token-splicing (##) and stringification (#)
3617 operators when expanding macros. It also supports variable-arity
3620 * GDB now supports inspecting extra signal information, exported by
3621 the new $_siginfo convenience variable. The feature is currently
3622 implemented on linux ARM, i386 and amd64.
3624 * GDB can now display the VFP floating point registers and NEON vector
3625 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3626 can provide these registers (requires Linux 2.6.30 or later). Remote
3627 and simulator targets may also provide them.
3629 * New remote packets
3632 Search memory for a sequence of bytes.
3635 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3636 operation over reliable transport links. Use of this packet is
3637 controlled by the `set remote noack-packet' command.
3640 Kill the process with the specified process ID. Use this in preference
3641 to `k' when multiprocess protocol extensions are supported.
3644 Obtains additional operating system information
3648 Read or write additional signal information.
3650 * Removed remote protocol undocumented extension
3652 An undocumented extension to the remote protocol's `S' stop reply
3653 packet that permited the stub to pass a process id was removed.
3654 Remote servers should use the `T' stop reply packet instead.
3656 * GDB now supports multiple function calling conventions according to the
3657 DWARF-2 DW_AT_calling_convention function attribute.
3659 * The SH target utilizes the aforementioned change to distinguish between gcc
3660 and Renesas calling convention. It also adds the new CLI commands
3661 `set/show sh calling-convention'.
3663 * GDB can now read compressed debug sections, as produced by GNU gold
3664 with the --compress-debug-sections=zlib flag.
3666 * 64-bit core files are now supported on AIX.
3668 * Thread switching is now supported on Tru64.
3670 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3671 which will be allocated using malloc later in program execution.
3673 * The qXfer:libraries:read remote procotol packet now allows passing a
3674 list of section offsets.
3676 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3677 conditions handling signals delivered during attach or thread creation
3678 have also been fixed.
3680 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3681 From the user's standpoint, all unqualified instances of True and False
3682 are treated as the standard definitions, regardless of context.
3684 * GDB now parses C++ symbol and type names more flexibly. For
3687 template<typename T> class C { };
3690 GDB will now correctly handle all of:
3692 ptype C<char const *>
3693 ptype C<char const*>
3694 ptype C<const char *>
3695 ptype C<const char*>
3697 * New features in the GDB remote stub, gdbserver
3699 - The "--wrapper" command-line argument tells gdbserver to use a
3700 wrapper program to launch programs for debugging.
3702 - On PowerPC and S/390 targets, it is now possible to use a single
3703 gdbserver executable to debug both 32-bit and 64-bit programs.
3704 (This requires gdbserver itself to be built as a 64-bit executable.)
3706 - gdbserver uses the new noack protocol mode for TCP connections to
3707 reduce communications latency, if also supported and enabled in GDB.
3709 - Support for the sparc64-linux-gnu target is now included in
3712 - The amd64-linux build of gdbserver now supports debugging both
3713 32-bit and 64-bit programs.
3715 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3716 now support hardware watchpoints, and will use them automatically
3721 GDB now has support for scripting using Python. Whether this is
3722 available is determined at configure time.
3724 New GDB commands can now be written in Python.
3726 * Ada tasking support
3728 Ada tasks can now be inspected in GDB. The following commands have
3732 Print the list of Ada tasks.
3734 Print detailed information about task number N.
3736 Print the task number of the current task.
3738 Switch the context of debugging to task number N.
3740 * Support for user-defined prefixed commands. The "define" command can
3741 add new commands to existing prefixes, e.g. "target".
3743 * Multi-inferior, multi-process debugging.
3745 GDB now has generalized support for multi-inferior debugging. See
3746 "Debugging Multiple Inferiors" in the manual for more information.
3747 Although availability still depends on target support, the command
3748 set is more uniform now. The GNU/Linux specific multi-forks support
3749 has been migrated to this new framework. This implied some user
3750 visible changes; see "New commands" and also "Removed commands"
3753 * Target descriptions can now describe the target OS ABI. See the
3754 "Target Description Format" section in the user manual for more
3757 * Target descriptions can now describe "compatible" architectures
3758 to indicate that the target can execute applications for a different
3759 architecture in addition to those for the main target architecture.
3760 See the "Target Description Format" section in the user manual for
3763 * Multi-architecture debugging.
3765 GDB now includes general supports for debugging applications on
3766 hybrid systems that use more than one single processor architecture
3767 at the same time. Each such hybrid architecture still requires
3768 specific support to be added. The only hybrid architecture supported
3769 in this version of GDB is the Cell Broadband Engine.
3771 * GDB now supports integrated debugging of Cell/B.E. applications that
3772 use both the PPU and SPU architectures. To enable support for hybrid
3773 Cell/B.E. debugging, you need to configure GDB to support both the
3774 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3775 --enable-targets configure option.
3777 * Non-stop mode debugging.
3779 For some targets, GDB now supports an optional mode of operation in
3780 which you can examine stopped threads while other threads continue
3781 to execute freely. This is referred to as non-stop mode, with the
3782 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3783 section in the user manual for more information.
3785 To be able to support remote non-stop debugging, a remote stub needs
3786 to implement the non-stop mode remote protocol extensions, as
3787 described in the "Remote Non-Stop" section of the user manual. The
3788 GDB remote stub, gdbserver, has been adjusted to support these
3789 extensions on linux targets.
3791 * New commands (for set/show, see "New options" below)
3793 catch syscall [NAME(S) | NUMBER(S)]
3794 Catch system calls. Arguments, which should be names of system
3795 calls or their numbers, mean catch only those syscalls. Without
3796 arguments, every syscall will be caught. When the inferior issues
3797 any of the specified syscalls, GDB will stop and announce the system
3798 call, both when it is called and when its call returns. This
3799 feature is currently available with a native GDB running on the
3800 Linux Kernel, under the following architectures: x86, x86_64,
3801 PowerPC and PowerPC64.
3803 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3805 Search memory for a sequence of bytes.
3807 maint set python print-stack
3808 maint show python print-stack
3809 Show a stack trace when an error is encountered in a Python script.
3812 Invoke CODE by passing it to the Python interpreter.
3817 These allow macros to be defined, undefined, and listed
3821 Show operating system information about processes.
3824 List the inferiors currently under GDB's control.
3827 Switch focus to inferior number NUM.
3830 Detach from inferior number NUM.
3833 Kill inferior number NUM.
3837 set spu stop-on-load
3838 show spu stop-on-load
3839 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3841 set spu auto-flush-cache
3842 show spu auto-flush-cache
3843 Control whether to automatically flush the software-managed cache
3844 during Cell/B.E. debugging.
3846 set sh calling-convention
3847 show sh calling-convention
3848 Control the calling convention used when calling SH target functions.
3851 show debug timestamp
3852 Control display of timestamps with GDB debugging output.
3854 set disassemble-next-line
3855 show disassemble-next-line
3856 Control display of disassembled source lines or instructions when
3859 set remote noack-packet
3860 show remote noack-packet
3861 Set/show the use of remote protocol QStartNoAckMode packet. See above
3862 under "New remote packets."
3864 set remote query-attached-packet
3865 show remote query-attached-packet
3866 Control use of remote protocol `qAttached' (query-attached) packet.
3868 set remote read-siginfo-object
3869 show remote read-siginfo-object
3870 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3873 set remote write-siginfo-object
3874 show remote write-siginfo-object
3875 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3878 set remote reverse-continue
3879 show remote reverse-continue
3880 Control use of remote protocol 'bc' (reverse-continue) packet.
3882 set remote reverse-step
3883 show remote reverse-step
3884 Control use of remote protocol 'bs' (reverse-step) packet.
3886 set displaced-stepping
3887 show displaced-stepping
3888 Control displaced stepping mode. Displaced stepping is a way to
3889 single-step over breakpoints without removing them from the debuggee.
3890 Also known as "out-of-line single-stepping".
3893 show debug displaced
3894 Control display of debugging info for displaced stepping.
3896 maint set internal-error
3897 maint show internal-error
3898 Control what GDB does when an internal error is detected.
3900 maint set internal-warning
3901 maint show internal-warning
3902 Control what GDB does when an internal warning is detected.
3907 Use a wrapper program to launch programs for debugging.
3909 set multiple-symbols (all|ask|cancel)
3910 show multiple-symbols
3911 The value of this variable can be changed to adjust the debugger behavior
3912 when an expression or a breakpoint location contains an ambiguous symbol
3913 name (an overloaded function name, for instance).
3915 set breakpoint always-inserted
3916 show breakpoint always-inserted
3917 Keep breakpoints always inserted in the target, as opposed to inserting
3918 them when resuming the target, and removing them when the target stops.
3919 This option can improve debugger performance on slow remote targets.
3921 set arm fallback-mode (arm|thumb|auto)
3922 show arm fallback-mode
3923 set arm force-mode (arm|thumb|auto)
3925 These commands control how ARM GDB determines whether instructions
3926 are ARM or Thumb. The default for both settings is auto, which uses
3927 the current CPSR value for instructions without symbols; previous
3928 versions of GDB behaved as if "set arm fallback-mode arm".
3930 set disable-randomization
3931 show disable-randomization
3932 Standalone programs run with the virtual address space randomization enabled
3933 by default on some platforms. This option keeps the addresses stable across
3934 multiple debugging sessions.
3938 Control whether other threads are stopped or not when some thread hits
3943 Requests that asynchronous execution is enabled in the target, if available.
3944 In this case, it's possible to resume target in the background, and interact
3945 with GDB while the target is running. "show target-async" displays the
3946 current state of asynchronous execution of the target.
3948 set target-wide-charset
3949 show target-wide-charset
3950 The target-wide-charset is the name of the character set that GDB
3951 uses when printing characters whose type is wchar_t.
3953 set tcp auto-retry (on|off)
3955 set tcp connect-timeout
3956 show tcp connect-timeout
3957 These commands allow GDB to retry failed TCP connections to a remote stub
3958 with a specified timeout period; this is useful if the stub is launched
3959 in parallel with GDB but may not be ready to accept connections immediately.
3961 set libthread-db-search-path
3962 show libthread-db-search-path
3963 Control list of directories which GDB will search for appropriate
3966 set schedule-multiple (on|off)
3967 show schedule-multiple
3968 Allow GDB to resume all threads of all processes or only threads of
3969 the current process.
3973 Use more aggressive caching for accesses to the stack. This improves
3974 performance of remote debugging (particularly backtraces) without
3975 affecting correctness.
3977 set interactive-mode (on|off|auto)
3978 show interactive-mode
3979 Control whether GDB runs in interactive mode (on) or not (off).
3980 When in interactive mode, GDB waits for the user to answer all
3981 queries. Otherwise, GDB does not wait and assumes the default
3982 answer. When set to auto (the default), GDB determines which
3983 mode to use based on the stdin settings.
3988 For program forks, this is replaced by the new more generic `info
3989 inferiors' command. To list checkpoints, you can still use the
3990 `info checkpoints' command, which was an alias for the `info forks'
3994 Replaced by the new `inferior' command. To switch between
3995 checkpoints, you can still use the `restart' command, which was an
3996 alias for the `fork' command.
3999 This is removed, since some targets don't have a notion of
4000 processes. To switch between processes, you can still use the
4001 `inferior' command using GDB's own inferior number.
4004 For program forks, this is replaced by the new more generic `kill
4005 inferior' command. To delete a checkpoint, you can still use the
4006 `delete checkpoint' command, which was an alias for the `delete
4010 For program forks, this is replaced by the new more generic `detach
4011 inferior' command. To detach a checkpoint, you can still use the
4012 `detach checkpoint' command, which was an alias for the `detach
4015 * New native configurations
4017 x86/x86_64 Darwin i[34567]86-*-darwin*
4019 x86_64 MinGW x86_64-*-mingw*
4023 Lattice Mico32 lm32-*
4024 x86 DICOS i[34567]86-*-dicos*
4025 x86_64 DICOS x86_64-*-dicos*
4028 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4029 (mingw32ce) debugging.
4035 These commands were actually not implemented on any target.
4037 *** Changes in GDB 6.8
4039 * New native configurations
4041 NetBSD/hppa hppa*-*netbsd*
4042 Xtensa GNU/Linux xtensa*-*-linux*
4046 NetBSD/hppa hppa*-*-netbsd*
4047 Xtensa GNU/Lunux xtensa*-*-linux*
4049 * Change in command line behavior -- corefiles vs. process ids.
4051 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4052 attaching to process NUMBER fails, GDB no longer attempts to open a
4053 core file named NUMBER. Attaching to a program using the -c option
4054 is no longer supported. Instead, use the '-p' or '--pid' options.
4056 * GDB can now be built as a native debugger for debugging Windows x86
4057 (mingw32) Portable Executable (PE) programs.
4059 * Pending breakpoints no longer change their number when their address
4062 * GDB now supports breakpoints with multiple locations,
4063 including breakpoints on C++ constructors, inside C++ templates,
4064 and in inlined functions.
4066 * GDB's ability to debug optimized code has been improved. GDB more
4067 accurately identifies function bodies and lexical blocks that occupy
4068 more than one contiguous range of addresses.
4070 * Target descriptions can now describe registers for PowerPC.
4072 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4073 registers on PowerPC targets.
4075 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4076 targets even when the libthread_db library is not available.
4078 * The GDB remote stub, gdbserver, now supports the new file transfer
4079 commands (remote put, remote get, and remote delete).
4081 * The GDB remote stub, gdbserver, now supports run and attach in
4082 extended-remote mode.
4084 * hppa*64*-*-hpux11* target broken
4085 The debugger is unable to start a program and fails with the following
4086 error: "Error trying to get information about dynamic linker".
4087 The gdb-6.7 release is also affected.
4089 * GDB now supports the --enable-targets= configure option to allow
4090 building a single GDB executable that supports multiple remote
4091 target architectures.
4093 * GDB now supports debugging C and C++ programs which use the
4094 Decimal Floating Point extension. In addition, the PowerPC target
4095 now has a set of pseudo-registers to inspect decimal float values
4096 stored in two consecutive float registers.
4098 * The -break-insert MI command can optionally create pending
4101 * Improved support for debugging Ada
4102 Many improvements to the Ada language support have been made. These
4104 - Better support for Ada2005 interface types
4105 - Improved handling of arrays and slices in general
4106 - Better support for Taft-amendment types
4107 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4109 - Improved command completion in Ada
4112 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4117 set print frame-arguments (all|scalars|none)
4118 show print frame-arguments
4119 The value of this variable can be changed to control which argument
4120 values should be printed by the debugger when displaying a frame.
4125 Transfer files to and from a remote target, and delete remote files.
4132 Transfer files to and from a remote target, and delete remote files.
4134 * New remote packets
4141 Open, close, read, write, and delete files on the remote system.
4144 Attach to an existing process on the remote system, in extended-remote
4148 Run a new process on the remote system, in extended-remote mode.
4150 *** Changes in GDB 6.7
4152 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4153 bfd, libiberty and opcodes, as revealed by static analysis donated by
4154 Coverity, Inc. (http://scan.coverity.com).
4156 * When looking up multiply-defined global symbols, GDB will now prefer the
4157 symbol definition in the current shared library if it was built using the
4158 -Bsymbolic linker option.
4160 * When the Text User Interface (TUI) is not configured, GDB will now
4161 recognize the -tui command-line option and print a message that the TUI
4164 * The GDB remote stub, gdbserver, now has lower overhead for high
4165 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4167 * GDB for MIPS targets now autodetects whether a remote target provides
4168 32-bit or 64-bit register values.
4170 * Support for C++ member pointers has been improved.
4172 * GDB now understands XML target descriptions, which specify the
4173 target's overall architecture. GDB can read a description from
4174 a local file or over the remote serial protocol.
4176 * Vectors of single-byte data use a new integer type which is not
4177 automatically displayed as character or string data.
4179 * The /s format now works with the print command. It displays
4180 arrays of single-byte integers and pointers to single-byte integers
4183 * Target descriptions can now describe target-specific registers,
4184 for architectures which have implemented the support (currently
4185 only ARM, M68K, and MIPS).
4187 * GDB and the GDB remote stub, gdbserver, now support the XScale
4190 * The GDB remote stub, gdbserver, has been updated to support
4191 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4192 has been rewritten to use the standard GDB remote protocol.
4194 * GDB can now step into C++ functions which are called through thunks.
4196 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4198 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4199 layout. It also supports a TextSeg= and DataSeg= response when only
4200 segment base addresses (rather than offsets) are available.
4202 * The /i format now outputs any trailing branch delay slot instructions
4203 immediately following the last instruction within the count specified.
4205 * The GDB remote protocol "T" stop reply packet now supports a
4206 "library" response. Combined with the new "qXfer:libraries:read"
4207 packet, this response allows GDB to debug shared libraries on targets
4208 where the operating system manages the list of loaded libraries (e.g.
4209 Windows and SymbianOS).
4211 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4212 (DLLs) on Windows and Windows CE targets.
4214 * GDB now supports a faster verification that a .debug file matches its binary
4215 according to its build-id signature, if the signature is present.
4221 Enable or disable hardware flow control (RTS/CTS) on the serial port
4222 when debugging using remote targets.
4224 set mem inaccessible-by-default
4225 show mem inaccessible-by-default
4226 If the target supplies a memory map, for instance via the remote
4227 protocol's "qXfer:memory-map:read" packet, setting this variable
4228 prevents GDB from accessing memory outside the memory map. This
4229 is useful for targets with memory mapped registers or which react
4230 badly to accesses of unmapped address space.
4232 set breakpoint auto-hw
4233 show breakpoint auto-hw
4234 If the target supplies a memory map, for instance via the remote
4235 protocol's "qXfer:memory-map:read" packet, setting this variable
4236 lets GDB use hardware breakpoints automatically for memory regions
4237 where it can not use software breakpoints. This covers both the
4238 "break" command and internal breakpoints used for other commands
4239 including "next" and "finish".
4242 catch exception unhandled
4243 Stop the program execution when Ada exceptions are raised.
4246 Stop the program execution when an Ada assertion failed.
4250 Set an alternate system root for target files. This is a more
4251 general version of "set solib-absolute-prefix", which is now
4252 an alias to "set sysroot".
4255 Provide extended SPU facility status information. This set of
4256 commands is available only when debugging the Cell/B.E. SPU
4259 * New native configurations
4261 OpenBSD/sh sh*-*openbsd*
4264 unset tdesc filename
4266 Use the specified local file as an XML target description, and do
4267 not query the target for its built-in description.
4271 OpenBSD/sh sh*-*-openbsd*
4272 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4273 Toshiba Media Processor mep-elf
4275 * New remote packets
4278 Ignore the specified signals; pass them directly to the debugged program
4279 without stopping other threads or reporting them to GDB.
4281 qXfer:features:read:
4282 Read an XML target description from the target, which describes its
4287 Read or write contents of an spufs file on the target system. These
4288 packets are available only on the Cell/B.E. SPU architecture.
4290 qXfer:libraries:read:
4291 Report the loaded shared libraries. Combined with new "T" packet
4292 response, this packet allows GDB to debug shared libraries on
4293 targets where the operating system manages the list of loaded
4294 libraries (e.g. Windows and SymbianOS).
4298 Support for these obsolete configurations has been removed.
4306 i[34567]86-*-lynxos*
4307 i[34567]86-*-netware*
4308 i[34567]86-*-sco3.2v5*
4309 i[34567]86-*-sco3.2v4*
4311 i[34567]86-*-sysv4.2*
4314 i[34567]86-*-unixware2*
4315 i[34567]86-*-unixware*
4324 * Other removed features
4331 Various m68k-only ROM monitors.
4338 Various Renesas ROM monitors and debugging interfaces for SH and
4343 Support for a Macraigor serial interface to on-chip debugging.
4344 GDB does not directly support the newer parallel or USB
4349 A debug information format. The predecessor to DWARF 2 and
4350 DWARF 3, which are still supported.
4352 Support for the HP aCC compiler on HP-UX/PA-RISC
4354 SOM-encapsulated symbolic debugging information, automatic
4355 invocation of pxdb, and the aCC custom C++ ABI. This does not
4356 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4357 with aCC can still be debugged on an assembly level.
4359 MIPS ".pdr" sections
4361 A MIPS-specific format used to describe stack frame layout
4362 in debugging information.
4366 GDB could work with an older version of Guile to debug
4367 the interpreter and Scheme programs running in it.
4369 set mips stack-arg-size
4370 set mips saved-gpreg-size
4372 Use "set mips abi" to control parameter passing for MIPS.
4374 *** Changes in GDB 6.6
4379 Cell Broadband Engine SPU spu-elf
4381 * GDB can now be configured as a cross-debugger targeting native Windows
4382 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4383 running on a Windows system over TCP/IP to debug Windows programs.
4385 * The GDB remote stub, gdbserver, has been updated to support Windows and
4386 Cygwin debugging. Both single-threaded and multi-threaded programs are
4389 * The "set trust-readonly-sections" command works again. This command was
4390 broken in GDB 6.3, 6.4, and 6.5.
4392 * The "load" command now supports writing to flash memory, if the remote
4393 stub provides the required support.
4395 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4396 longer requires symbolic debug information (e.g. DWARF-2).
4401 unset substitute-path
4402 show substitute-path
4403 Manage a list of substitution rules that GDB uses to rewrite the name
4404 of the directories where the sources are located. This can be useful
4405 for instance when the sources were moved to a different location
4406 between compilation and debugging.
4410 Print each CLI command as it is executed. Each command is prefixed with
4411 a number of `+' symbols representing the nesting depth.
4412 The source command now has a `-v' option to enable the same feature.
4416 The ARM Demon monitor support (RDP protocol, "target rdp").
4418 Kernel Object Display, an embedded debugging feature which only worked with
4419 an obsolete version of Cisco IOS.
4421 The 'set download-write-size' and 'show download-write-size' commands.
4423 * New remote packets
4426 Tell a stub about GDB client features, and request remote target features.
4427 The first feature implemented is PacketSize, which allows the target to
4428 specify the size of packets it can handle - to minimize the number of
4429 packets required and improve performance when connected to a remote
4433 Fetch an OS auxilliary vector from the remote stub. This packet is a
4434 more efficient replacement for qPart:auxv:read.
4436 qXfer:memory-map:read:
4437 Fetch a memory map from the remote stub, including information about
4438 RAM, ROM, and flash memory devices.
4443 Erase and program a flash memory device.
4445 * Removed remote packets
4448 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4449 used it, and only gdbserver implemented it.
4451 *** Changes in GDB 6.5
4455 Renesas M32C/M16C m32c-elf
4457 Morpho Technologies ms1 ms1-elf
4461 init-if-undefined Initialize a convenience variable, but
4462 only if it doesn't already have a value.
4464 The following commands are presently only implemented for native GNU/Linux:
4466 checkpoint Save a snapshot of the program state.
4468 restart <n> Return the program state to a
4469 previously saved state.
4471 info checkpoints List currently saved checkpoints.
4473 delete-checkpoint <n> Delete a previously saved checkpoint.
4475 set|show detach-on-fork Tell gdb whether to detach from a newly
4476 forked process, or to keep debugging it.
4478 info forks List forks of the user program that
4479 are available to be debugged.
4481 fork <n> Switch to debugging one of several
4482 forks of the user program that are
4483 available to be debugged.
4485 delete-fork <n> Delete a fork from the list of forks
4486 that are available to be debugged (and
4487 kill the forked process).
4489 detach-fork <n> Delete a fork from the list of forks
4490 that are available to be debugged (and
4491 allow the process to continue).
4495 Morpho Technologies ms2 ms1-elf
4497 * Improved Windows host support
4499 GDB now builds as a cross debugger hosted on i686-mingw32, including
4500 native console support, and remote communications using either
4501 network sockets or serial ports.
4503 * Improved Modula-2 language support
4505 GDB can now print most types in the Modula-2 syntax. This includes:
4506 basic types, set types, record types, enumerated types, range types,
4507 pointer types and ARRAY types. Procedure var parameters are correctly
4508 printed and hexadecimal addresses and character constants are also
4509 written in the Modula-2 syntax. Best results can be obtained by using
4510 GNU Modula-2 together with the -gdwarf-2 command line option.
4514 The ARM rdi-share module.
4516 The Netware NLM debug server.
4518 *** Changes in GDB 6.4
4520 * New native configurations
4522 OpenBSD/arm arm*-*-openbsd*
4523 OpenBSD/mips64 mips64-*-openbsd*
4527 Morpho Technologies ms1 ms1-elf
4529 * New command line options
4531 --batch-silent As for --batch, but totally silent.
4532 --return-child-result The debugger will exist with the same value
4533 the child (debugged) program exited with.
4534 --eval-command COMMAND, -ex COMMAND
4535 Execute a single GDB CLI command. This may be
4536 specified multiple times and in conjunction
4537 with the --command (-x) option.
4539 * Deprecated commands removed
4541 The following commands, that were deprecated in 2000, have been
4545 set|show arm disassembly-flavor set|show arm disassembler
4546 othernames set arm disassembler
4547 set|show remotedebug set|show debug remote
4548 set|show archdebug set|show debug arch
4549 set|show eventdebug set|show debug event
4552 * New BSD user-level threads support
4554 It is now possible to debug programs using the user-level threads
4555 library on OpenBSD and FreeBSD. Currently supported (target)
4558 FreeBSD/amd64 x86_64-*-freebsd*
4559 FreeBSD/i386 i386-*-freebsd*
4560 OpenBSD/i386 i386-*-openbsd*
4562 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4563 are not yet supported.
4565 * New support for Matsushita MN10300 w/sim added
4566 (Work in progress). mn10300-elf.
4568 * REMOVED configurations and files
4570 VxWorks and the XDR protocol *-*-vxworks
4571 Motorola MCORE mcore-*-*
4572 National Semiconductor NS32000 ns32k-*-*
4574 * New "set print array-indexes" command
4576 After turning this setting "on", GDB prints the index of each element
4577 when displaying arrays. The default is "off" to preserve the previous
4580 * VAX floating point support
4582 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4584 * User-defined command support
4586 In addition to using $arg0..$arg9 for argument passing, it is now possible
4587 to use $argc to determine now many arguments have been passed. See the
4588 section on user-defined commands in the user manual for more information.
4590 *** Changes in GDB 6.3:
4592 * New command line option
4594 GDB now accepts -l followed by a number to set the timeout for remote
4597 * GDB works with GCC -feliminate-dwarf2-dups
4599 GDB now supports a more compact representation of DWARF-2 debug
4600 information using DW_FORM_ref_addr references. These are produced
4601 by GCC with the option -feliminate-dwarf2-dups and also by some
4602 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4603 to use -feliminate-dwarf2-dups.
4605 * Internationalization
4607 When supported by the host system, GDB will be built with
4608 internationalization (libintl). The task of marking up the sources is
4609 continued, we're looking forward to our first translation.
4613 Initial support for debugging programs compiled with the GNAT
4614 implementation of the Ada programming language has been integrated
4615 into GDB. In this release, support is limited to expression evaluation.
4617 * New native configurations
4619 GNU/Linux/m32r m32r-*-linux-gnu
4623 GDB's remote protocol now includes support for the 'p' packet. This
4624 packet is used to fetch individual registers from a remote inferior.
4626 * END-OF-LIFE registers[] compatibility module
4628 GDB's internal register infrastructure has been completely rewritten.
4629 The new infrastructure making possible the implementation of key new
4630 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4633 GDB 6.3 will be the last release to include the the registers[]
4634 compatibility module that allowed out-of-date configurations to
4635 continue to work. This change directly impacts the following
4645 powerpc bdm protocol
4647 Unless there is activity to revive these configurations, they will be
4648 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4650 * OBSOLETE configurations and files
4652 Configurations that have been declared obsolete in this release have
4653 been commented out. Unless there is activity to revive these
4654 configurations, the next release of GDB will have their sources
4655 permanently REMOVED.
4664 *** Changes in GDB 6.2.1:
4666 * MIPS `break main; run' gave an heuristic-fence-post warning
4668 When attempting to run even a simple program, a warning about
4669 heuristic-fence-post being hit would be reported. This problem has
4672 * MIPS IRIX 'long double' crashed GDB
4674 When examining a long double variable, GDB would get a segmentation
4675 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4676 IRIX long double values).
4680 A bug in the VAX stack code was causing problems with the "next"
4681 command. This problem has been fixed.
4683 *** Changes in GDB 6.2:
4685 * Fix for ``many threads''
4687 On GNU/Linux systems that use the NPTL threads library, a program
4688 rapidly creating and deleting threads would confuse GDB leading to the
4691 ptrace: No such process.
4692 thread_db_get_info: cannot get thread info: generic error
4694 This problem has been fixed.
4696 * "-async" and "-noasync" options removed.
4698 Support for the broken "-noasync" option has been removed (it caused
4701 * New ``start'' command.
4703 This command runs the program until the begining of the main procedure.
4705 * New BSD Kernel Data Access Library (libkvm) interface
4707 Using ``target kvm'' it is now possible to debug kernel core dumps and
4708 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4709 platforms. Currently supported (native-only) configurations are:
4711 FreeBSD/amd64 x86_64-*-freebsd*
4712 FreeBSD/i386 i?86-*-freebsd*
4713 NetBSD/i386 i?86-*-netbsd*
4714 NetBSD/m68k m68*-*-netbsd*
4715 NetBSD/sparc sparc-*-netbsd*
4716 OpenBSD/amd64 x86_64-*-openbsd*
4717 OpenBSD/i386 i?86-*-openbsd*
4718 OpenBSD/m68k m68*-openbsd*
4719 OpenBSD/sparc sparc-*-openbsd*
4721 * Signal trampoline code overhauled
4723 Many generic problems with GDB's signal handling code have been fixed.
4724 These include: backtraces through non-contiguous stacks; recognition
4725 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4726 call; backtrace through a signal trampoline; step into and out of
4727 signal handlers; and single-stepping in the signal trampoline.
4729 Please note that kernel bugs are a limiting factor here. These
4730 features have been shown to work on an s390 GNU/Linux system that
4731 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4733 * Cygwin support for DWARF 2 added.
4735 * New native configurations
4737 GNU/Linux/hppa hppa*-*-linux*
4738 OpenBSD/hppa hppa*-*-openbsd*
4739 OpenBSD/m68k m68*-*-openbsd*
4740 OpenBSD/m88k m88*-*-openbsd*
4741 OpenBSD/powerpc powerpc-*-openbsd*
4742 NetBSD/vax vax-*-netbsd*
4743 OpenBSD/vax vax-*-openbsd*
4745 * END-OF-LIFE frame compatibility module
4747 GDB's internal frame infrastructure has been completely rewritten.
4748 The new infrastructure making it possible to support key new features
4749 including DWARF 2 Call Frame Information. To aid in the task of
4750 migrating old configurations to this new infrastructure, a
4751 compatibility module, that allowed old configurations to continue to
4752 work, was also included.
4754 GDB 6.2 will be the last release to include this frame compatibility
4755 module. This change directly impacts the following configurations:
4765 Unless there is activity to revive these configurations, they will be
4766 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4768 * REMOVED configurations and files
4770 Sun 3, running SunOS 3 m68*-*-sunos3*
4771 Sun 3, running SunOS 4 m68*-*-sunos4*
4772 Sun 2, running SunOS 3 m68000-*-sunos3*
4773 Sun 2, running SunOS 4 m68000-*-sunos4*
4774 Motorola 680x0 running LynxOS m68*-*-lynxos*
4775 AT&T 3b1/Unix pc m68*-att-*
4776 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4777 decstation mips-dec-* mips-little-*
4778 riscos mips-*-riscos* mips-*-sysv*
4779 sonymips mips-sony-*
4780 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4782 *** Changes in GDB 6.1.1:
4784 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4786 The TUI (Text-mode User Interface) is now built as part of a default
4787 GDB configuration. It is enabled by either selecting the TUI with the
4788 command line option "-i=tui" or by running the separate "gdbtui"
4789 program. For more information on the TUI, see the manual "Debugging
4792 * Pending breakpoint support (also included in GDB 6.1)
4794 Support has been added to allow you to specify breakpoints in shared
4795 libraries that have not yet been loaded. If a breakpoint location
4796 cannot be found, and the "breakpoint pending" option is set to auto,
4797 GDB queries you if you wish to make the breakpoint pending on a future
4798 shared-library load. If and when GDB resolves the breakpoint symbol,
4799 the pending breakpoint is removed as one or more regular breakpoints
4802 Pending breakpoints are very useful for GCJ Java debugging.
4804 * Fixed ISO-C build problems
4806 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4807 non ISO-C code that stopped them being built using a more strict ISO-C
4808 compiler (e.g., IBM's C compiler).
4810 * Fixed build problem on IRIX 5
4812 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4813 wasn't able to compile compile on an IRIX 5 system.
4815 * Added execute permission to gdb/gdbserver/configure
4817 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4818 permission. This bug would cause configure to fail on a number of
4819 systems (Solaris, IRIX). Ref: server/519.
4821 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4823 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4824 has been updated to use constant array sizes.
4826 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4828 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4829 its generated DWARF Call Frame Info. This encoding was causing GDB to
4830 panic, that panic has been fixed. Ref: gdb/1628.
4832 * Fixed a problem when examining parameters in shared library code.
4834 When examining parameters in optimized shared library code generated
4835 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4836 not available''. GDB now correctly displays the variable's value.
4838 *** Changes in GDB 6.1:
4840 * Removed --with-mmalloc
4842 Support for the mmalloc memory manager has been removed, as it
4843 conflicted with the internal gdb byte cache.
4845 * Changes in AMD64 configurations
4847 The AMD64 target now includes the %cs and %ss registers. As a result
4848 the AMD64 remote protocol has changed; this affects the floating-point
4849 and SSE registers. If you rely on those registers for your debugging,
4850 you should upgrade gdbserver on the remote side.
4852 * Revised SPARC target
4854 The SPARC target has been completely revised, incorporating the
4855 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4856 support for LynxOS and SunOS 4 has been dropped. Calling functions
4857 from within GDB on operating systems with a non-executable stack
4858 (Solaris, OpenBSD) now works.
4862 GDB has a new C++ demangler which does a better job on the mangled
4863 names generated by current versions of g++. It also runs faster, so
4864 with this and other changes gdb should now start faster on large C++
4867 * DWARF 2 Location Expressions
4869 GDB support for location expressions has been extended to support function
4870 arguments and frame bases. Older versions of GDB could crash when they
4873 * C++ nested types and namespaces
4875 GDB's support for nested types and namespaces in C++ has been
4876 improved, especially if you use the DWARF 2 debugging format. (This
4877 is the default for recent versions of GCC on most platforms.)
4878 Specifically, if you have a class "Inner" defined within a class or
4879 namespace "Outer", then GDB realizes that the class's name is
4880 "Outer::Inner", not simply "Inner". This should greatly reduce the
4881 frequency of complaints about not finding RTTI symbols. In addition,
4882 if you are stopped at inside of a function defined within a namespace,
4883 GDB modifies its name lookup accordingly.
4885 * New native configurations
4887 NetBSD/amd64 x86_64-*-netbsd*
4888 OpenBSD/amd64 x86_64-*-openbsd*
4889 OpenBSD/alpha alpha*-*-openbsd*
4890 OpenBSD/sparc sparc-*-openbsd*
4891 OpenBSD/sparc64 sparc64-*-openbsd*
4893 * New debugging protocols
4895 M32R with SDI protocol m32r-*-elf*
4897 * "set prompt-escape-char" command deleted.
4899 The command "set prompt-escape-char" has been deleted. This command,
4900 and its very obscure effet on GDB's prompt, was never documented,
4901 tested, nor mentioned in the NEWS file.
4903 * OBSOLETE configurations and files
4905 Configurations that have been declared obsolete in this release have
4906 been commented out. Unless there is activity to revive these
4907 configurations, the next release of GDB will have their sources
4908 permanently REMOVED.
4910 Sun 3, running SunOS 3 m68*-*-sunos3*
4911 Sun 3, running SunOS 4 m68*-*-sunos4*
4912 Sun 2, running SunOS 3 m68000-*-sunos3*
4913 Sun 2, running SunOS 4 m68000-*-sunos4*
4914 Motorola 680x0 running LynxOS m68*-*-lynxos*
4915 AT&T 3b1/Unix pc m68*-att-*
4916 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4917 decstation mips-dec-* mips-little-*
4918 riscos mips-*-riscos* mips-*-sysv*
4919 sonymips mips-sony-*
4920 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4922 * REMOVED configurations and files
4924 SGI Irix-4.x mips-sgi-irix4 or iris4
4925 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4926 Z8000 simulator z8k-zilog-none or z8ksim
4927 Matsushita MN10200 w/simulator mn10200-*-*
4928 H8/500 simulator h8500-hitachi-hms or h8500hms
4929 HP/PA running BSD hppa*-*-bsd*
4930 HP/PA running OSF/1 hppa*-*-osf*
4931 HP/PA Pro target hppa*-*-pro*
4932 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4933 386BSD i[3456]86-*-bsd*
4934 Sequent family i[3456]86-sequent-sysv4*
4935 i[3456]86-sequent-sysv*
4936 i[3456]86-sequent-bsd*
4937 SPARC running LynxOS sparc-*-lynxos*
4938 SPARC running SunOS 4 sparc-*-sunos4*
4939 Tsqware Sparclet sparclet-*-*
4940 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4942 *** Changes in GDB 6.0:
4946 Support for debugging the Objective-C programming language has been
4947 integrated into GDB.
4949 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4951 DWARF 2's Call Frame Information makes available compiler generated
4952 information that more exactly describes the program's run-time stack.
4953 By using this information, GDB is able to provide more robust stack
4956 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4957 have been updated to use a new backtrace mechanism which includes
4958 DWARF 2 CFI support.
4962 GDB's remote protocol has been extended to include support for hosted
4963 file I/O (where the remote target uses GDB's file system). See GDB's
4964 remote protocol documentation for details.
4966 * All targets using the new architecture framework.
4968 All of GDB's targets have been updated to use the new internal
4969 architecture framework. The way is now open for future GDB releases
4970 to include cross-architecture native debugging support (i386 on amd64,
4973 * GNU/Linux's Thread Local Storage (TLS)
4975 GDB now includes support for for the GNU/Linux implementation of
4976 per-thread variables.
4978 * GNU/Linux's Native POSIX Thread Library (NPTL)
4980 GDB's thread code has been updated to work with either the new
4981 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4983 * Separate debug info.
4985 GDB, in conjunction with BINUTILS, now supports a mechanism for
4986 automatically loading debug information from a separate file. Instead
4987 of shipping full debug and non-debug versions of system libraries,
4988 system integrators can now instead ship just the stripped libraries
4989 and optional debug files.
4991 * DWARF 2 Location Expressions
4993 DWARF 2 Location Expressions allow the compiler to more completely
4994 describe the location of variables (even in optimized code) to the
4997 GDB now includes preliminary support for location expressions (support
4998 for DW_OP_piece is still missing).
5002 A number of long standing bugs that caused GDB to die while starting a
5003 Java application have been fixed. GDB's Java support is now
5004 considered "useable".
5006 * GNU/Linux support for fork, vfork, and exec.
5008 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5009 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5012 * GDB supports logging output to a file
5014 There are two new commands, "set logging" and "show logging", which can be
5015 used to capture GDB's output to a file.
5017 * The meaning of "detach" has changed for gdbserver
5019 The "detach" command will now resume the application, as documented. To
5020 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5023 * d10v, m68hc11 `regs' command deprecated
5025 The `info registers' command has been updated so that it displays the
5026 registers using a format identical to the old `regs' command.
5030 A new command, "maint set profile on/off", has been added. This command can
5031 be used to enable or disable profiling while running GDB, to profile a
5032 session or a set of commands. In addition there is a new configure switch,
5033 "--enable-profiling", which will cause GDB to be compiled with profiling
5034 data, for more informative profiling results.
5036 * Default MI syntax changed to "mi2".
5038 The default MI (machine interface) syntax, enabled by the command line
5039 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5040 "mi1", can be enabled by specifying the option "-i=mi1".
5042 Support for the original "mi0" syntax (included in GDB 5.0) has been
5045 Fix for gdb/192: removed extraneous space when displaying frame level.
5046 Fix for gdb/672: update changelist is now output in mi list format.
5047 Fix for gdb/702: a -var-assign that updates the value now shows up
5048 in a subsequent -var-update.
5050 * New native configurations.
5052 FreeBSD/amd64 x86_64-*-freebsd*
5054 * Multi-arched targets.
5056 HP/PA HPUX11 hppa*-*-hpux*
5057 Renesas M32R/D w/simulator m32r-*-elf*
5059 * OBSOLETE configurations and files
5061 Configurations that have been declared obsolete in this release have
5062 been commented out. Unless there is activity to revive these
5063 configurations, the next release of GDB will have their sources
5064 permanently REMOVED.
5066 Z8000 simulator z8k-zilog-none or z8ksim
5067 Matsushita MN10200 w/simulator mn10200-*-*
5068 H8/500 simulator h8500-hitachi-hms or h8500hms
5069 HP/PA running BSD hppa*-*-bsd*
5070 HP/PA running OSF/1 hppa*-*-osf*
5071 HP/PA Pro target hppa*-*-pro*
5072 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5073 Sequent family i[3456]86-sequent-sysv4*
5074 i[3456]86-sequent-sysv*
5075 i[3456]86-sequent-bsd*
5076 Tsqware Sparclet sparclet-*-*
5077 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5079 * REMOVED configurations and files
5082 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5083 IBM AIX PS/2 i[3456]86-*-aix
5084 i386 running Mach 3.0 i[3456]86-*-mach3*
5085 i386 running Mach i[3456]86-*-mach*
5086 i386 running OSF/1 i[3456]86-*osf1mk*
5087 HP/Apollo 68k Family m68*-apollo*-sysv*,
5089 m68*-hp-bsd*, m68*-hp-hpux*
5090 Argonaut Risc Chip (ARC) arc-*-*
5091 Mitsubishi D30V d30v-*-*
5092 Fujitsu FR30 fr30-*-elf*
5093 OS/9000 i[34]86-*-os9k
5094 I960 with MON960 i960-*-coff
5096 * MIPS $fp behavior changed
5098 The convenience variable $fp, for the MIPS, now consistently returns
5099 the address of the current frame's base. Previously, depending on the
5100 context, $fp could refer to either $sp or the current frame's base
5101 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5102 The GNU Source-Level Debugger''.
5104 *** Changes in GDB 5.3:
5106 * GNU/Linux shared library multi-threaded performance improved.
5108 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5109 `/proc', in preference to `ptrace' for memory reads. This may result
5110 in an improvement in the start-up time of multi-threaded, shared
5111 library applications when run under GDB. One GDB user writes: ``loads
5112 shared libs like mad''.
5114 * ``gdbserver'' now supports multi-threaded applications on some targets
5116 Support for debugging multi-threaded applications which use
5117 the GNU/Linux LinuxThreads package has been added for
5118 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5119 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5121 * GDB now supports C/C++ preprocessor macros.
5123 GDB now expands preprocessor macro invocations in C/C++ expressions,
5124 and provides various commands for showing macro definitions and how
5127 The new command `macro expand EXPRESSION' expands any macro
5128 invocations in expression, and shows the result.
5130 The new command `show macro MACRO-NAME' shows the definition of the
5131 macro named MACRO-NAME, and where it was defined.
5133 Most compilers don't include information about macros in the debugging
5134 information by default. In GCC 3.1, for example, you need to compile
5135 your program with the options `-gdwarf-2 -g3'. If the macro
5136 information is present in the executable, GDB will read it.
5138 * Multi-arched targets.
5140 DEC Alpha (partial) alpha*-*-*
5141 DEC VAX (partial) vax-*-*
5143 National Semiconductor NS32000 (partial) ns32k-*-*
5144 Motorola 68000 (partial) m68k-*-*
5145 Motorola MCORE mcore-*-*
5149 Fujitsu FRV architecture added by Red Hat frv*-*-*
5152 * New native configurations
5154 Alpha NetBSD alpha*-*-netbsd*
5155 SH NetBSD sh*-*-netbsdelf*
5156 MIPS NetBSD mips*-*-netbsd*
5157 UltraSPARC NetBSD sparc64-*-netbsd*
5159 * OBSOLETE configurations and files
5161 Configurations that have been declared obsolete in this release have
5162 been commented out. Unless there is activity to revive these
5163 configurations, the next release of GDB will have their sources
5164 permanently REMOVED.
5166 Mitsubishi D30V d30v-*-*
5167 OS/9000 i[34]86-*-os9k
5168 IBM AIX PS/2 i[3456]86-*-aix
5169 Fujitsu FR30 fr30-*-elf*
5170 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5171 Argonaut Risc Chip (ARC) arc-*-*
5172 i386 running Mach 3.0 i[3456]86-*-mach3*
5173 i386 running Mach i[3456]86-*-mach*
5174 i386 running OSF/1 i[3456]86-*osf1mk*
5175 HP/Apollo 68k Family m68*-apollo*-sysv*,
5177 m68*-hp-bsd*, m68*-hp-hpux*
5178 I960 with MON960 i960-*-coff
5180 * OBSOLETE languages
5182 CHILL, a Pascal like language used by telecommunications companies.
5184 * REMOVED configurations and files
5186 AMD 29k family via UDI a29k-amd-udi, udi29k
5187 A29K VxWorks a29k-*-vxworks
5188 AMD 29000 embedded, using EBMON a29k-none-none
5189 AMD 29000 embedded with COFF a29k-none-coff
5190 AMD 29000 embedded with a.out a29k-none-aout
5192 testsuite/gdb.hp/gdb.threads-hp/ directory
5194 * New command "set max-user-call-depth <nnn>"
5196 This command allows the user to limit the call depth of user-defined
5197 commands. The default is 1024.
5199 * Changes in FreeBSD/i386 native debugging.
5201 Support for the "generate-core-file" has been added.
5203 * New commands "dump", "append", and "restore".
5205 These commands allow data to be copied from target memory
5206 to a bfd-format or binary file (dump and append), and back
5207 from a file into memory (restore).
5209 * Improved "next/step" support on multi-processor Alpha Tru64.
5211 The previous single-step mechanism could cause unpredictable problems,
5212 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5213 of a software single-step mechanism prevents this.
5215 *** Changes in GDB 5.2.1:
5223 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5224 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5225 Fix, by Joel Brobecker imported from mainline.
5227 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5228 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5229 Fix, by Fred Fish, imported from mainline.
5231 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5232 Surprisingly enough, it works now.
5233 By Michal Ludvig, imported from mainline.
5235 i386 hardware watchpoint support:
5236 avoid misses on second run for some targets.
5237 By Pierre Muller, imported from mainline.
5239 *** Changes in GDB 5.2:
5241 * New command "set trust-readonly-sections on[off]".
5243 This command is a hint that tells gdb that read-only sections
5244 really are read-only (ie. that their contents will not change).
5245 In this mode, gdb will go to the object file rather than the
5246 target to read memory from read-only sections (such as ".text").
5247 This can be a significant performance improvement on some
5248 (notably embedded) targets.
5250 * New command "generate-core-file" (or "gcore").
5252 This new gdb command allows the user to drop a core file of the child
5253 process state at any time. So far it's been implemented only for
5254 GNU/Linux and Solaris, but should be relatively easily ported to other
5255 hosts. Argument is core file name (defaults to core.<pid>).
5257 * New command line option
5259 GDB now accepts --pid or -p followed by a process id.
5261 * Change in command line behavior -- corefiles vs. process ids.
5263 There is a subtle behavior in the way in which GDB handles
5264 command line arguments. The first non-flag argument is always
5265 a program to debug, but the second non-flag argument may either
5266 be a corefile or a process id. Previously, GDB would attempt to
5267 open the second argument as a corefile, and if that failed, would
5268 issue a superfluous error message and then attempt to attach it as
5269 a process. Now, if the second argument begins with a non-digit,
5270 it will be treated as a corefile. If it begins with a digit,
5271 GDB will attempt to attach it as a process, and if no such process
5272 is found, will then attempt to open it as a corefile.
5274 * Changes in ARM configurations.
5276 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5277 configuration is fully multi-arch.
5279 * New native configurations
5281 ARM NetBSD arm*-*-netbsd*
5282 x86 OpenBSD i[3456]86-*-openbsd*
5283 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5284 Sparc64 running FreeBSD sparc64-*-freebsd*
5288 Sanyo XStormy16 xstormy16-elf
5290 * OBSOLETE configurations and files
5292 Configurations that have been declared obsolete in this release have
5293 been commented out. Unless there is activity to revive these
5294 configurations, the next release of GDB will have their sources
5295 permanently REMOVED.
5297 AMD 29k family via UDI a29k-amd-udi, udi29k
5298 A29K VxWorks a29k-*-vxworks
5299 AMD 29000 embedded, using EBMON a29k-none-none
5300 AMD 29000 embedded with COFF a29k-none-coff
5301 AMD 29000 embedded with a.out a29k-none-aout
5303 testsuite/gdb.hp/gdb.threads-hp/ directory
5305 * REMOVED configurations and files
5307 TI TMS320C80 tic80-*-*
5309 PowerPC Solaris powerpcle-*-solaris*
5310 PowerPC Windows NT powerpcle-*-cygwin32
5311 PowerPC Netware powerpc-*-netware*
5312 Harris/CXUX m88k m88*-harris-cxux*
5313 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5314 ns32k-utek-sysv* ns32k-utek-*
5315 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5316 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5317 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5318 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5319 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5321 * Changes to command line processing
5323 The new `--args' feature can be used to specify command-line arguments
5324 for the inferior from gdb's command line.
5326 * Changes to key bindings
5328 There is a new `operate-and-get-next' function bound to `C-o'.
5330 *** Changes in GDB 5.1.1
5332 Fix compile problem on DJGPP.
5334 Fix a problem with floating-point registers on the i386 being
5337 Fix to stop GDB crashing on .debug_str debug info.
5339 Numerous documentation fixes.
5341 Numerous testsuite fixes.
5343 *** Changes in GDB 5.1:
5345 * New native configurations
5347 Alpha FreeBSD alpha*-*-freebsd*
5348 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5349 MIPS GNU/Linux mips*-*-linux*
5350 MIPS SGI Irix 6.x mips*-sgi-irix6*
5351 ia64 AIX ia64-*-aix*
5352 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5356 Motorola 68HC11 and 68HC12 m68hc11-elf
5358 UltraSparc running GNU/Linux sparc64-*-linux*
5360 * OBSOLETE configurations and files
5362 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5363 Harris/CXUX m88k m88*-harris-cxux*
5364 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5365 ns32k-utek-sysv* ns32k-utek-*
5366 TI TMS320C80 tic80-*-*
5368 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5369 PowerPC Solaris powerpcle-*-solaris*
5370 PowerPC Windows NT powerpcle-*-cygwin32
5371 PowerPC Netware powerpc-*-netware*
5372 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5373 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5374 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5375 Apple Macintosh (MPW) host N/A
5377 stuff.c (Program to stuff files into a specially prepared space in kdb)
5378 kdb-start.c (Main loop for the standalone kernel debugger)
5380 Configurations that have been declared obsolete in this release have
5381 been commented out. Unless there is activity to revive these
5382 configurations, the next release of GDB will have their sources
5383 permanently REMOVED.
5385 * REMOVED configurations and files
5387 Altos 3068 m68*-altos-*
5388 Convex c1-*-*, c2-*-*
5390 ARM RISCix arm-*-* (as host)
5394 * GDB has been converted to ISO C.
5396 GDB's source code has been converted to ISO C. In particular, the
5397 sources are fully protoized, and rely on standard headers being
5402 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5404 * The MI enabled by default.
5406 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5407 revised and enabled by default. Packages which use GDB as a debugging
5408 engine behind a UI or another front end are encouraged to switch to
5409 using the GDB/MI interface, instead of the old annotations interface
5410 which is now deprecated.
5412 * Support for debugging Pascal programs.
5414 GDB now includes support for debugging Pascal programs. The following
5415 main features are supported:
5417 - Pascal-specific data types such as sets;
5419 - automatic recognition of Pascal sources based on file-name
5422 - Pascal-style display of data types, variables, and functions;
5424 - a Pascal expression parser.
5426 However, some important features are not yet supported.
5428 - Pascal string operations are not supported at all;
5430 - there are some problems with boolean types;
5432 - Pascal type hexadecimal constants are not supported
5433 because they conflict with the internal variables format;
5435 - support for Pascal objects and classes is not full yet;
5437 - unlike Pascal, GDB is case-sensitive for symbol names.
5439 * Changes in completion.
5441 Commands such as `shell', `run' and `set args', which pass arguments
5442 to inferior programs, now complete on file names, similar to what
5443 users expect at the shell prompt.
5445 Commands which accept locations, such as `disassemble', `print',
5446 `breakpoint', `until', etc. now complete on filenames as well as
5447 program symbols. Thus, if you type "break foob TAB", and the source
5448 files linked into the programs include `foobar.c', that file name will
5449 be one of the candidates for completion. However, file names are not
5450 considered for completion after you typed a colon that delimits a file
5451 name from a name of a function in that file, as in "break foo.c:bar".
5453 `set demangle-style' completes on available demangling styles.
5455 * New platform-independent commands:
5457 It is now possible to define a post-hook for a command as well as a
5458 hook that runs before the command. For more details, see the
5459 documentation of `hookpost' in the GDB manual.
5461 * Changes in GNU/Linux native debugging.
5463 Support for debugging multi-threaded programs has been completely
5464 revised for all platforms except m68k and sparc. You can now debug as
5465 many threads as your system allows you to have.
5467 Attach/detach is supported for multi-threaded programs.
5469 Support for SSE registers was added for x86. This doesn't work for
5470 multi-threaded programs though.
5472 * Changes in MIPS configurations.
5474 Multi-arch support is enabled for all MIPS configurations.
5476 GDB can now be built as native debugger on SGI Irix 6.x systems for
5477 debugging n32 executables. (Debugging 64-bit executables is not yet
5480 * Unified support for hardware watchpoints in all x86 configurations.
5482 Most (if not all) native x86 configurations support hardware-assisted
5483 breakpoints and watchpoints in a unified manner. This support
5484 implements debug register sharing between watchpoints, which allows to
5485 put a virtually infinite number of watchpoints on the same address,
5486 and also supports watching regions up to 16 bytes with several debug
5489 The new maintenance command `maintenance show-debug-regs' toggles
5490 debugging print-outs in functions that insert, remove, and test
5491 watchpoints and hardware breakpoints.
5493 * Changes in the DJGPP native configuration.
5495 New command ``info dos sysinfo'' displays assorted information about
5496 the CPU, OS, memory, and DPMI server.
5498 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5499 display information about segment descriptors stored in GDT, LDT, and
5502 New commands ``info dos pde'' and ``info dos pte'' display entries
5503 from Page Directory and Page Tables (for now works with CWSDPMI only).
5504 New command ``info dos address-pte'' displays the Page Table entry for
5505 a given linear address.
5507 GDB can now pass command lines longer than 126 characters to the
5508 program being debugged (requires an update to the libdbg.a library
5509 which is part of the DJGPP development kit).
5511 DWARF2 debug info is now supported.
5513 It is now possible to `step' and `next' through calls to `longjmp'.
5515 * Changes in documentation.
5517 All GDB documentation was converted to GFDL, the GNU Free
5518 Documentation License.
5520 Tracepoints-related commands are now fully documented in the GDB
5523 TUI, the Text-mode User Interface, is now documented in the manual.
5525 Tracepoints-related commands are now fully documented in the GDB
5528 The "GDB Internals" manual now has an index. It also includes
5529 documentation of `ui_out' functions, GDB coding standards, x86
5530 hardware watchpoints, and memory region attributes.
5532 * GDB's version number moved to ``version.in''
5534 The Makefile variable VERSION has been replaced by the file
5535 ``version.in''. People creating GDB distributions should update the
5536 contents of this file.
5540 GUD support is now a standard part of the EMACS distribution.
5542 *** Changes in GDB 5.0:
5544 * Improved support for debugging FP programs on x86 targets
5546 Unified and much-improved support for debugging floating-point
5547 programs on all x86 targets. In particular, ``info float'' now
5548 displays the FP registers in the same format on all x86 targets, with
5549 greater level of detail.
5551 * Improvements and bugfixes in hardware-assisted watchpoints
5553 It is now possible to watch array elements, struct members, and
5554 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5555 on x86 targets no longer erroneously trigger when the address is
5558 * Improvements in the native DJGPP version of GDB
5560 The distribution now includes all the scripts and auxiliary files
5561 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5562 machines ``out of the box''.
5564 The DJGPP version can now debug programs that use signals. It is
5565 possible to catch signals that happened in the debuggee, deliver
5566 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5567 would kill the program being debugged.) Programs that hook hardware
5568 interrupts (keyboard, timer, etc.) can also be debugged.
5570 It is now possible to debug DJGPP programs that redirect their
5571 standard handles or switch them to raw (as opposed to cooked) mode, or
5572 even close them. The command ``run < foo > bar'' works as expected,
5573 and ``info terminal'' reports useful information about the debuggee's
5574 terminal, including raw/cooked mode, redirection, etc.
5576 The DJGPP version now uses termios functions for console I/O, which
5577 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5580 DOS-style file names with drive letters are now fully supported by
5583 It is now possible to debug DJGPP programs that switch their working
5584 directory. It is also possible to rerun the debuggee any number of
5585 times without restarting GDB; thus, you can use the same setup,
5586 breakpoints, etc. for many debugging sessions.
5588 * New native configurations
5590 ARM GNU/Linux arm*-*-linux*
5591 PowerPC GNU/Linux powerpc-*-linux*
5595 Motorola MCore mcore-*-*
5596 x86 VxWorks i[3456]86-*-vxworks*
5597 PowerPC VxWorks powerpc-*-vxworks*
5598 TI TMS320C80 tic80-*-*
5600 * OBSOLETE configurations
5602 Altos 3068 m68*-altos-*
5603 Convex c1-*-*, c2-*-*
5605 ARM RISCix arm-*-* (as host)
5608 Configurations that have been declared obsolete will be commented out,
5609 but the code will be left in place. If there is no activity to revive
5610 these configurations before the next release of GDB, the sources will
5611 be permanently REMOVED.
5613 * Gould support removed
5615 Support for the Gould PowerNode and NP1 has been removed.
5617 * New features for SVR4
5619 On SVR4 native platforms (such as Solaris), if you attach to a process
5620 without first loading a symbol file, GDB will now attempt to locate and
5621 load symbols from the running process's executable file.
5623 * Many C++ enhancements
5625 C++ support has been greatly improved. Overload resolution now works properly
5626 in almost all cases. RTTI support is on the way.
5628 * Remote targets can connect to a sub-program
5630 A popen(3) style serial-device has been added. This device starts a
5631 sub-process (such as a stand-alone simulator) and then communicates
5632 with that. The sub-program to run is specified using the syntax
5633 ``|<program> <args>'' vis:
5635 (gdb) set remotedebug 1
5636 (gdb) target extended-remote |mn10300-elf-sim program-args
5638 * MIPS 64 remote protocol
5640 A long standing bug in the mips64 remote protocol where by GDB
5641 expected certain 32 bit registers (ex SR) to be transfered as 32
5642 instead of 64 bits has been fixed.
5644 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5645 added to provide backward compatibility with older versions of GDB.
5647 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5649 The command ``set remotebinarydownload'' command has been replaced by
5650 ``set remote X-packet''. Other commands in ``set remote'' family
5651 include ``set remote P-packet''.
5653 * Breakpoint commands accept ranges.
5655 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5656 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5657 ``tracepoint passcount'' also accepts a range of tracepoints.
5659 * ``apropos'' command added.
5661 The ``apropos'' command searches through command names and
5662 documentation strings, printing out matches, making it much easier to
5663 try to find a command that does what you are looking for.
5667 A new machine oriented interface (MI) has been added to GDB. This
5668 interface is designed for debug environments running GDB as a separate
5669 process. This is part of the long term libGDB project. See the
5670 "GDB/MI" chapter of the GDB manual for further information. It can be
5671 enabled by configuring with:
5673 .../configure --enable-gdbmi
5675 *** Changes in GDB-4.18:
5677 * New native configurations
5679 HP-UX 10.20 hppa*-*-hpux10.20
5680 HP-UX 11.x hppa*-*-hpux11.0*
5681 M68K GNU/Linux m68*-*-linux*
5685 Fujitsu FR30 fr30-*-elf*
5686 Intel StrongARM strongarm-*-*
5687 Mitsubishi D30V d30v-*-*
5689 * OBSOLETE configurations
5691 Gould PowerNode, NP1 np1-*-*, pn-*-*
5693 Configurations that have been declared obsolete will be commented out,
5694 but the code will be left in place. If there is no activity to revive
5695 these configurations before the next release of GDB, the sources will
5696 be permanently REMOVED.
5700 As a compatibility experiment, GDB's source files buildsym.h and
5701 buildsym.c have been converted to pure standard C, no longer
5702 containing any K&R compatibility code. We believe that all systems in
5703 use today either come with a standard C compiler, or have a GCC port
5704 available. If this is not true, please report the affected
5705 configuration to bug-gdb@gnu.org immediately. See the README file for
5706 information about getting a standard C compiler if you don't have one
5711 GDB now uses readline 2.2.
5713 * set extension-language
5715 You can now control the mapping between filename extensions and source
5716 languages by using the `set extension-language' command. For instance,
5717 you can ask GDB to treat .c files as C++ by saying
5718 set extension-language .c c++
5719 The command `info extensions' lists all of the recognized extensions
5720 and their associated languages.
5722 * Setting processor type for PowerPC and RS/6000
5724 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5725 you can use the `set processor' command to specify what variant of the
5726 PowerPC family you are debugging. The command
5730 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5731 following PowerPC and RS6000 variants:
5733 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5734 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5736 403GC IBM PowerPC 403GC
5737 505 Motorola PowerPC 505
5738 860 Motorola PowerPC 860 or 850
5739 601 Motorola PowerPC 601
5740 602 Motorola PowerPC 602
5741 603 Motorola/IBM PowerPC 603 or 603e
5742 604 Motorola PowerPC 604 or 604e
5743 750 Motorola/IBM PowerPC 750 or 750
5745 At the moment, this command just tells GDB what to name the
5746 special-purpose processor registers. Since almost all the affected
5747 registers are inaccessible to user-level programs, this command is
5748 only useful for remote debugging in its present form.
5752 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5753 more extensive support for HP-UX. Added features include shared
5754 library support, kernel threads and hardware watchpoints for 11.00,
5755 support for HP's ANSI C and C++ compilers, and a compatibility mode
5756 for xdb and dbx commands.
5760 HP's donation includes the new concept of catchpoints, which is a
5761 generalization of the old catch command. On HP-UX, it is now possible
5762 to catch exec, fork, and vfork, as well as library loading.
5764 This means that the existing catch command has changed; its first
5765 argument now specifies the type of catch to be set up. See the
5766 output of "help catch" for a list of catchpoint types.
5768 * Debugging across forks
5770 On HP-UX, you can choose which process to debug when a fork() happens
5775 HP has donated a curses-based terminal user interface (TUI). To get
5776 it, build with --enable-tui. Although this can be enabled for any
5777 configuration, at present it only works for native HP debugging.
5779 * GDB remote protocol additions
5781 A new protocol packet 'X' that writes binary data is now available.
5782 Default behavior is to try 'X', then drop back to 'M' if the stub
5783 fails to respond. The settable variable `remotebinarydownload'
5784 allows explicit control over the use of 'X'.
5786 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5787 full 64-bit address. The command
5789 set remoteaddresssize 32
5791 can be used to revert to the old behaviour. For existing remote stubs
5792 the change should not be noticed, as the additional address information
5795 In order to assist in debugging stubs, you may use the maintenance
5796 command `packet' to send any text string to the stub. For instance,
5798 maint packet heythere
5800 sends the packet "$heythere#<checksum>". Note that it is very easy to
5801 disrupt a debugging session by sending the wrong packet at the wrong
5804 The compare-sections command allows you to compare section data on the
5805 target to what is in the executable file without uploading or
5806 downloading, by comparing CRC checksums.
5808 * Tracing can collect general expressions
5810 You may now collect general expressions at tracepoints. This requires
5811 further additions to the target-side stub; see tracepoint.c and
5812 doc/agentexpr.texi for further details.
5814 * mask-address variable for Mips
5816 For Mips targets, you may control the zeroing of the upper 32 bits of
5817 a 64-bit address by entering `set mask-address on'. This is mainly
5818 of interest to users of embedded R4xxx and R5xxx processors.
5820 * Higher serial baud rates
5822 GDB's serial code now allows you to specify baud rates 57600, 115200,
5823 230400, and 460800 baud. (Note that your host system may not be able
5824 to achieve all of these rates.)
5828 The i960 configuration now includes an initial implementation of a
5829 builtin simulator, contributed by Jim Wilson.
5832 *** Changes in GDB-4.17:
5834 * New native configurations
5836 Alpha GNU/Linux alpha*-*-linux*
5837 Unixware 2.x i[3456]86-unixware2*
5838 Irix 6.x mips*-sgi-irix6*
5839 PowerPC GNU/Linux powerpc-*-linux*
5840 PowerPC Solaris powerpcle-*-solaris*
5841 Sparc GNU/Linux sparc-*-linux*
5842 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5846 Argonaut Risc Chip (ARC) arc-*-*
5847 Hitachi H8/300S h8300*-*-*
5848 Matsushita MN10200 w/simulator mn10200-*-*
5849 Matsushita MN10300 w/simulator mn10300-*-*
5850 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5851 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5852 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5853 Mitsubishi D10V w/simulator d10v-*-*
5854 Mitsubishi M32R/D w/simulator m32r-*-elf*
5855 Tsqware Sparclet sparclet-*-*
5856 NEC V850 w/simulator v850-*-*
5858 * New debugging protocols
5860 ARM with RDI protocol arm*-*-*
5861 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5862 DDB and LSI variants of PMON protocol mips*-*-*
5863 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5864 PowerPC with SDS protocol powerpc{,le}-*-eabi
5865 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5869 All configurations can now understand and use the DWARF 2 debugging
5870 format. The choice is automatic, if the symbol file contains DWARF 2
5875 GDB now includes basic Java language support. This support is
5876 only useful with Java compilers that produce native machine code.
5878 * solib-absolute-prefix and solib-search-path
5880 For SunOS and SVR4 shared libraries, you may now set the prefix for
5881 loading absolute shared library symbol files, and the search path for
5882 locating non-absolute shared library symbol files.
5884 * Live range splitting
5886 GDB can now effectively debug code for which GCC has performed live
5887 range splitting as part of its optimization. See gdb/doc/LRS for
5888 more details on the expected format of the stabs information.
5892 GDB's support for the GNU Hurd, including thread debugging, has been
5893 updated to work with current versions of the Hurd.
5897 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5898 instruction set. ARM GDB automatically detects when Thumb
5899 instructions are in use, and adjusts disassembly and backtracing
5904 GDB's MIPS target configurations now handle the MIP16 16-bit
5909 GDB now includes support for overlays; if an executable has been
5910 linked such that multiple sections are based at the same address, GDB
5911 will decide which section to use for symbolic info. You can choose to
5912 control the decision manually, using overlay commands, or implement
5913 additional target-side support and use "overlay load-target" to bring
5914 in the overlay mapping. Do "help overlay" for more detail.
5918 The command "info symbol <address>" displays information about
5919 the symbol at the specified address.
5923 The standard remote protocol now includes an extension that allows
5924 asynchronous collection and display of trace data. This requires
5925 extensive support in the target-side debugging stub. Tracing mode
5926 includes a new interaction mode in GDB and new commands: see the
5927 file tracepoint.c for more details.
5931 Configurations for embedded MIPS now include a simulator contributed
5932 by Cygnus Solutions. The simulator supports the instruction sets
5933 of most MIPS variants.
5937 Sparc configurations may now include the ERC32 simulator contributed
5938 by the European Space Agency. The simulator is not built into
5939 Sparc targets by default; configure with --enable-sim to include it.
5943 For target configurations that may include multiple variants of a
5944 basic architecture (such as MIPS and SH), you may now set the
5945 architecture explicitly. "set arch" sets, "info arch" lists
5946 the possible architectures.
5948 *** Changes in GDB-4.16:
5950 * New native configurations
5952 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5953 M68K NetBSD m68k-*-netbsd*
5954 PowerPC AIX 4.x powerpc-*-aix*
5955 PowerPC MacOS powerpc-*-macos*
5956 PowerPC Windows NT powerpcle-*-cygwin32
5957 RS/6000 AIX 4.x rs6000-*-aix4*
5961 ARM with RDP protocol arm-*-*
5962 I960 with MON960 i960-*-coff
5963 MIPS VxWorks mips*-*-vxworks*
5964 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5965 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5967 Matra Sparclet sparclet-*-*
5971 The powerpc-eabi configuration now includes the PSIM simulator,
5972 contributed by Andrew Cagney, with assistance from Mike Meissner.
5973 PSIM is a very elaborate model of the PowerPC, including not only
5974 basic instruction set execution, but also details of execution unit
5975 performance and I/O hardware. See sim/ppc/README for more details.
5979 GDB now works with Solaris 2.5.
5981 * Windows 95/NT native
5983 GDB will now work as a native debugger on Windows 95 and Windows NT.
5984 To build it from source, you must use the "gnu-win32" environment,
5985 which uses a DLL to emulate enough of Unix to run the GNU tools.
5986 Further information, binaries, and sources are available at
5987 ftp.cygnus.com, under pub/gnu-win32.
5989 * dont-repeat command
5991 If a user-defined command includes the command `dont-repeat', then the
5992 command will not be repeated if the user just types return. This is
5993 useful if the command is time-consuming to run, so that accidental
5994 extra keystrokes don't run the same command many times.
5996 * Send break instead of ^C
5998 The standard remote protocol now includes an option to send a break
5999 rather than a ^C to the target in order to interrupt it. By default,
6000 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6002 * Remote protocol timeout
6004 The standard remote protocol includes a new variable `remotetimeout'
6005 that allows you to set the number of seconds before GDB gives up trying
6006 to read from the target. The default value is 2.
6008 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6010 By default GDB will automatically keep track of objects as they are
6011 loaded and unloaded by the dynamic linker. By using the command `set
6012 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6013 when shared library events occur, thus allowing you to set breakpoints
6014 in shared libraries which are explicitly loaded by the inferior.
6016 Note this feature does not work on hpux8. On hpux9 you must link
6017 /usr/lib/end.o into your program. This feature should work
6018 automatically on hpux10.
6020 * Irix 5.x hardware watchpoint support
6022 Irix 5 configurations now support the use of hardware watchpoints.
6024 * Mips protocol "SYN garbage limit"
6026 When debugging a Mips target using the `target mips' protocol, you
6027 may set the number of characters that GDB will ignore by setting
6028 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6029 every character. The default value is 1050.
6031 * Recording and replaying remote debug sessions
6033 If you set `remotelogfile' to the name of a file, gdb will write to it
6034 a recording of a remote debug session. This recording may then be
6035 replayed back to gdb using "gdbreplay". See gdbserver/README for
6036 details. This is useful when you have a problem with GDB while doing
6037 remote debugging; you can make a recording of the session and send it
6038 to someone else, who can then recreate the problem.
6040 * Speedups for remote debugging
6042 GDB includes speedups for downloading and stepping MIPS systems using
6043 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6044 and more efficient S-record downloading.
6046 * Memory use reductions and statistics collection
6048 GDB now uses less memory and reports statistics about memory usage.
6049 Try the `maint print statistics' command, for example.
6051 *** Changes in GDB-4.15:
6053 * Psymtabs for XCOFF
6055 The symbol reader for AIX GDB now uses partial symbol tables. This
6056 can greatly improve startup time, especially for large executables.
6058 * Remote targets use caching
6060 Remote targets now use a data cache to speed up communication with the
6061 remote side. The data cache could lead to incorrect results because
6062 it doesn't know about volatile variables, thus making it impossible to
6063 debug targets which use memory mapped I/O devices. `set remotecache
6064 off' turns the the data cache off.
6066 * Remote targets may have threads
6068 The standard remote protocol now includes support for multiple threads
6069 in the target system, using new protocol commands 'H' and 'T'. See
6070 gdb/remote.c for details.
6074 If GDB is configured with `--enable-netrom', then it will include
6075 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6076 acts as though it is a bank of ROM on the target board, but you can
6077 write into it over the network. GDB's support consists only of
6078 support for fast loading into the emulated ROM; to debug, you must use
6079 another protocol, such as standard remote protocol. The usual
6080 sequence is something like
6082 target nrom <netrom-hostname>
6084 target remote <netrom-hostname>:1235
6088 GDB now includes support for the Apple Macintosh, as a host only. It
6089 may be run as either an MPW tool or as a standalone application, and
6090 it can debug through the serial port. All the usual GDB commands are
6091 available, but to the target command, you must supply "serial" as the
6092 device type instead of "/dev/ttyXX". See mpw-README in the main
6093 directory for more information on how to build. The MPW configuration
6094 scripts */mpw-config.in support only a few targets, and only the
6095 mips-idt-ecoff target has been tested.
6099 GDB configuration now uses autoconf. This is not user-visible,
6100 but does simplify configuration and building.
6104 GDB now supports hpux10.
6106 *** Changes in GDB-4.14:
6108 * New native configurations
6110 x86 FreeBSD i[345]86-*-freebsd
6111 x86 NetBSD i[345]86-*-netbsd
6112 NS32k NetBSD ns32k-*-netbsd
6113 Sparc NetBSD sparc-*-netbsd
6117 A29K VxWorks a29k-*-vxworks
6118 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6119 CPU32 EST-300 emulator m68*-*-est*
6120 PowerPC ELF powerpc-*-elf
6123 * Alpha OSF/1 support for procfs
6125 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6126 possible to attach to running processes. As the mounting of the /proc
6127 filesystem is optional on the Alpha, GDB automatically determines
6128 the availability of /proc during startup. This can lead to problems
6129 if /proc is unmounted after GDB has been started.
6131 * Arguments to user-defined commands
6133 User commands may accept up to 10 arguments separated by whitespace.
6134 Arguments are accessed within the user command via $arg0..$arg9. A
6137 print $arg0 + $arg1 + $arg2
6139 To execute the command use:
6142 Defines the command "adder" which prints the sum of its three arguments.
6143 Note the arguments are text substitutions, so they may reference variables,
6144 use complex expressions, or even perform inferior function calls.
6146 * New `if' and `while' commands
6148 This makes it possible to write more sophisticated user-defined
6149 commands. Both commands take a single argument, which is the
6150 expression to evaluate, and must be followed by the commands to
6151 execute, one per line, if the expression is nonzero, the list being
6152 terminated by the word `end'. The `if' command list may include an
6153 `else' word, which causes the following commands to be executed only
6154 if the expression is zero.
6156 * Fortran source language mode
6158 GDB now includes partial support for Fortran 77. It will recognize
6159 Fortran programs and can evaluate a subset of Fortran expressions, but
6160 variables and functions may not be handled correctly. GDB will work
6161 with G77, but does not yet know much about symbols emitted by other
6164 * Better HPUX support
6166 Most debugging facilities now work on dynamic executables for HPPAs
6167 running hpux9 or later. You can attach to running dynamically linked
6168 processes, but by default the dynamic libraries will be read-only, so
6169 for instance you won't be able to put breakpoints in them. To change
6170 that behavior do the following before running the program:
6176 This will cause the libraries to be mapped private and read-write.
6177 To revert to the normal behavior, do this:
6183 You cannot set breakpoints or examine data in the library until after
6184 the library is loaded if the function/data symbols do not have
6187 GDB can now also read debug symbols produced by the HP C compiler on
6188 HPPAs (sorry, no C++, Fortran or 68k support).
6190 * Target byte order now dynamically selectable
6192 You can choose which byte order to use with a target system, via the
6193 commands "set endian big" and "set endian little", and you can see the
6194 current setting by using "show endian". You can also give the command
6195 "set endian auto", in which case GDB will use the byte order
6196 associated with the executable. Currently, only embedded MIPS
6197 configurations support dynamic selection of target byte order.
6199 * New DOS host serial code
6201 This version uses DPMI interrupts to handle buffered I/O, so you
6202 no longer need to run asynctsr when debugging boards connected to
6205 *** Changes in GDB-4.13:
6207 * New "complete" command
6209 This lists all the possible completions for the rest of the line, if it
6210 were to be given as a command itself. This is intended for use by emacs.
6212 * Trailing space optional in prompt
6214 "set prompt" no longer adds a space for you after the prompt you set. This
6215 allows you to set a prompt which ends in a space or one that does not.
6217 * Breakpoint hit counts
6219 "info break" now displays a count of the number of times the breakpoint
6220 has been hit. This is especially useful in conjunction with "ignore"; you
6221 can ignore a large number of breakpoint hits, look at the breakpoint info
6222 to see how many times the breakpoint was hit, then run again, ignoring one
6223 less than that number, and this will get you quickly to the last hit of
6226 * Ability to stop printing at NULL character
6228 "set print null-stop" will cause GDB to stop printing the characters of
6229 an array when the first NULL is encountered. This is useful when large
6230 arrays actually contain only short strings.
6232 * Shared library breakpoints
6234 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6235 breakpoints in shared libraries before the executable is run.
6237 * Hardware watchpoints
6239 There is a new hardware breakpoint for the watch command for sparclite
6240 targets. See gdb/sparclite/hw_breakpoint.note.
6242 Hardware watchpoints are also now supported under GNU/Linux.
6246 Annotations have been added. These are for use with graphical interfaces,
6247 and are still experimental. Currently only gdba.el uses these.
6249 * Improved Irix 5 support
6251 GDB now works properly with Irix 5.2.
6253 * Improved HPPA support
6255 GDB now works properly with the latest GCC and GAS.
6257 * New native configurations
6259 Sequent PTX4 i[34]86-sequent-ptx4
6260 HPPA running OSF/1 hppa*-*-osf*
6261 Atari TT running SVR4 m68*-*-sysv4*
6262 RS/6000 LynxOS rs6000-*-lynxos*
6266 OS/9000 i[34]86-*-os9k
6267 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6270 * Hitachi SH7000 and E7000-PC ICE support
6272 There is now support for communicating with the Hitachi E7000-PC ICE.
6273 This is available automatically when GDB is configured for the SH.
6277 As usual, a variety of small fixes and improvements, both generic
6278 and configuration-specific. See the ChangeLog for more detail.
6280 *** Changes in GDB-4.12:
6282 * Irix 5 is now supported
6286 GDB-4.12 on the HPPA has a number of changes which make it unable
6287 to debug the output from the currently released versions of GCC and
6288 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6289 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6290 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6293 *** Changes in GDB-4.11:
6295 * User visible changes:
6299 The "set remotedebug" option is now consistent between the mips remote
6300 target, remote targets using the gdb-specific protocol, UDI (AMD's
6301 debug protocol for the 29k) and the 88k bug monitor. It is now an
6302 integer specifying a debug level (normally 0 or 1, but 2 means more
6303 debugging info for the mips target).
6305 * DEC Alpha native support
6307 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6308 debug info, but GDB works fairly well with the DEC compiler and should
6309 work with a future GCC release. See the README file for a few
6310 Alpha-specific notes.
6312 * Preliminary thread implementation
6314 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6316 * LynxOS native and target support for 386
6318 This release has been hosted on LynxOS 2.2, and also can be configured
6319 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6322 * Improvements in C++ mangling/demangling.
6324 This release has much better g++ debugging, specifically in name
6325 mangling/demangling, virtual function calls, print virtual table,
6326 call methods, ...etc.
6328 *** Changes in GDB-4.10:
6330 * User visible changes:
6332 Remote debugging using the GDB-specific (`target remote') protocol now
6333 supports the `load' command. This is only useful if you have some
6334 other way of getting the stub to the target system, and you can put it
6335 somewhere in memory where it won't get clobbered by the download.
6337 Filename completion now works.
6339 When run under emacs mode, the "info line" command now causes the
6340 arrow to point to the line specified. Also, "info line" prints
6341 addresses in symbolic form (as well as hex).
6343 All vxworks based targets now support a user settable option, called
6344 vxworks-timeout. This option represents the number of seconds gdb
6345 should wait for responses to rpc's. You might want to use this if
6346 your vxworks target is, perhaps, a slow software simulator or happens
6347 to be on the far side of a thin network line.
6351 This release contains support for using a DEC alpha as a GDB host for
6352 cross debugging. Native alpha debugging is not supported yet.
6355 *** Changes in GDB-4.9:
6359 This is the first GDB release which is accompanied by a matching testsuite.
6360 The testsuite requires installation of dejagnu, which should be available
6361 via ftp from most sites that carry GNU software.
6365 'Cfront' style demangling has had its name changed to 'ARM' style, to
6366 emphasize that it was written from the specifications in the C++ Annotated
6367 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6368 disclaimers, it still generated too much confusion with users attempting to
6369 use gdb with AT&T cfront.
6373 GDB now uses a standard remote interface to a simulator library.
6374 So far, the library contains simulators for the Zilog Z8001/2, the
6375 Hitachi H8/300, H8/500 and Super-H.
6377 * New targets supported
6379 H8/300 simulator h8300-hitachi-hms or h8300hms
6380 H8/500 simulator h8500-hitachi-hms or h8500hms
6381 SH simulator sh-hitachi-hms or sh
6382 Z8000 simulator z8k-zilog-none or z8ksim
6383 IDT MIPS board over serial line mips-idt-ecoff
6385 Cross-debugging to GO32 targets is supported. It requires a custom
6386 version of the i386-stub.c module which is integrated with the
6387 GO32 memory extender.
6389 * New remote protocols
6391 MIPS remote debugging protocol.
6393 * New source languages supported
6395 This version includes preliminary support for Chill, a Pascal like language
6396 used by telecommunications companies. Chill support is also being integrated
6397 into the GNU compiler, but we don't know when it will be publically available.
6400 *** Changes in GDB-4.8:
6402 * HP Precision Architecture supported
6404 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6405 version of this support was available as a set of patches from the
6406 University of Utah. GDB does not support debugging of programs
6407 compiled with the HP compiler, because HP will not document their file
6408 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6409 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6411 Many problems in the preliminary version have been fixed.
6413 * Faster and better demangling
6415 We have improved template demangling and fixed numerous bugs in the GNU style
6416 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6417 character types (wchar_t) are now supported. Demangling of each symbol is now
6418 only done once, and is cached when the symbol table for a file is read in.
6419 This results in a small increase in memory usage for C programs, a moderate
6420 increase in memory usage for C++ programs, and a fantastic speedup in
6423 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6424 from the specifications in the Annotated Reference Manual, which AT&T's
6425 compiler does not actually implement.
6427 * G++ multiple inheritance compiler problem
6429 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6430 inheritance lattices was reworked to properly discover ambiguities. We
6431 recently found an example which causes this new algorithm to fail in a
6432 very subtle way, producing bad debug information for those classes.
6433 The file 'gcc.patch' (in this directory) can be applied to gcc to
6434 circumvent the problem. A future GCC release will contain a complete
6437 The previous G++ debug info problem (mentioned below for the gdb-4.7
6438 release) is fixed in gcc version 2.3.2.
6440 * Improved configure script
6442 The `configure' script will now attempt to guess your system type if
6443 you don't supply a host system type. The old scheme of supplying a
6444 host system triplet is preferable over using this. All the magic is
6445 done in the new `config.guess' script. Examine it for details.
6447 We have also brought our configure script much more in line with the FSF's
6448 version. It now supports the --with-xxx options. In particular,
6449 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6450 The resulting GDB will not be able to read arbitrary object file formats --
6451 only the format ``expected'' to be used on the configured target system.
6452 We hope to make this the default in a future release.
6454 * Documentation improvements
6456 There's new internal documentation on how to modify GDB, and how to
6457 produce clean changes to the code. We implore people to read it
6458 before submitting changes.
6460 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6461 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6462 `info' files are also provided. To build `info' files from scratch,
6463 you will need the latest `makeinfo' release, which will be available in
6464 a future texinfo-X.Y release.
6466 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6467 We're not sure exactly which versions have this problem, but it has
6468 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6469 or better. If that isn't possible, there is a patch in
6470 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6471 around this problem.
6475 GDB now supports array constants that can be used in expressions typed in by
6476 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6477 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6480 The new directory `gdb/sparclite' contains a program that demonstrates
6481 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6483 * New native hosts supported
6485 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6486 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6488 * New targets supported
6490 AMD 29k family via UDI a29k-amd-udi or udi29k
6492 * New file formats supported
6494 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6495 HPUX core files, and SCO 3.2v2 core files.
6499 Attaching to processes now works again; thanks for the many bug reports.
6501 We have also stomped on a bunch of core dumps caused by
6502 printf_filtered("%s") problems.
6504 We eliminated a copyright problem on the rpc and ptrace header files
6505 for VxWorks, which was discovered at the last minute during the 4.7
6506 release. You should now be able to build a VxWorks GDB.
6508 You can now interrupt gdb while an attached process is running. This
6509 will cause the attached process to stop, and give control back to GDB.
6511 We fixed problems caused by using too many file descriptors
6512 for reading symbols from object files and libraries. This was
6513 especially a problem for programs that used many (~100) shared
6516 The `step' command now only enters a subroutine if there is line number
6517 information for the subroutine. Otherwise it acts like the `next'
6518 command. Previously, `step' would enter subroutines if there was
6519 any debugging information about the routine. This avoids problems
6520 when using `cc -g1' on MIPS machines.
6522 * Internal improvements
6524 GDB's internal interfaces have been improved to make it easier to support
6525 debugging of multiple languages in the future.
6527 GDB now uses a common structure for symbol information internally.
6528 Minimal symbols (derived from linkage symbols in object files), partial
6529 symbols (from a quick scan of debug information), and full symbols
6530 contain a common subset of information, making it easier to write
6531 shared code that handles any of them.
6533 * New command line options
6535 We now accept --silent as an alias for --quiet.
6539 The memory-mapped-malloc library is now licensed under the GNU Library
6540 General Public License.
6542 *** Changes in GDB-4.7:
6544 * Host/native/target split
6546 GDB has had some major internal surgery to untangle the support for
6547 hosts and remote targets. Now, when you configure GDB for a remote
6548 target, it will no longer load in all of the support for debugging
6549 local programs on the host. When fully completed and tested, this will
6550 ensure that arbitrary host/target combinations are possible.
6552 The primary conceptual shift is to separate the non-portable code in
6553 GDB into three categories. Host specific code is required any time GDB
6554 is compiled on that host, regardless of the target. Target specific
6555 code relates to the peculiarities of the target, but can be compiled on
6556 any host. Native specific code is everything else: it can only be
6557 built when the host and target are the same system. Child process
6558 handling and core file support are two common `native' examples.
6560 GDB's use of /proc for controlling Unix child processes is now cleaner.
6561 It has been split out into a single module under the `target_ops' vector,
6562 plus two native-dependent functions for each system that uses /proc.
6564 * New hosts supported
6566 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6567 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6568 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6570 * New targets supported
6572 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6573 68030 and CPU32 m68030-*-*, m68332-*-*
6575 * New native hosts supported
6577 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6578 (386bsd is not well tested yet)
6579 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6581 * New file formats supported
6583 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6584 supports reading of `a.out.adobe' object files, which are an a.out
6585 format extended with minimal information about multiple sections.
6589 `show copying' is the same as the old `info copying'.
6590 `show warranty' is the same as `info warrantee'.
6591 These were renamed for consistency. The old commands continue to work.
6593 `info handle' is a new alias for `info signals'.
6595 You can now define pre-command hooks, which attach arbitrary command
6596 scripts to any command. The commands in the hook will be executed
6597 prior to the user's command. You can also create a hook which will be
6598 executed whenever the program stops. See gdb.texinfo.
6602 We now deal with Cfront style name mangling, and can even extract type
6603 info from mangled symbols. GDB can automatically figure out which
6604 symbol mangling style your C++ compiler uses.
6606 Calling of methods and virtual functions has been improved as well.
6610 The crash that occured when debugging Sun Ansi-C compiled binaries is
6611 fixed. This was due to mishandling of the extra N_SO stabs output
6614 We also finally got Ultrix 4.2 running in house, and fixed core file
6615 support, with help from a dozen people on the net.
6617 John M. Farrell discovered that the reason that single-stepping was so
6618 slow on all of the Mips based platforms (primarily SGI and DEC) was
6619 that we were trying to demangle and lookup a symbol used for internal
6620 purposes on every instruction that was being stepped through. Changing
6621 the name of that symbol so that it couldn't be mistaken for a C++
6622 mangled symbol sped things up a great deal.
6624 Rich Pixley sped up symbol lookups in general by getting much smarter
6625 about when C++ symbol mangling is necessary. This should make symbol
6626 completion (TAB on the command line) much faster. It's not as fast as
6627 we'd like, but it's significantly faster than gdb-4.6.
6631 A new user controllable variable 'call_scratch_address' can
6632 specify the location of a scratch area to be used when GDB
6633 calls a function in the target. This is necessary because the
6634 usual method of putting the scratch area on the stack does not work
6635 in systems that have separate instruction and data spaces.
6637 We integrated changes to support the 29k UDI (Universal Debugger
6638 Interface), but discovered at the last minute that we didn't have all
6639 of the appropriate copyright paperwork. We are working with AMD to
6640 resolve this, and hope to have it available soon.
6644 We have sped up the remote serial line protocol, especially for targets
6645 with lots of registers. It now supports a new `expedited status' ('T')
6646 message which can be used in place of the existing 'S' status message.
6647 This allows the remote stub to send only the registers that GDB
6648 needs to make a quick decision about single-stepping or conditional
6649 breakpoints, eliminating the need to fetch the entire register set for
6650 each instruction being stepped through.
6652 The GDB remote serial protocol now implements a write-through cache for
6653 registers, only re-reading the registers if the target has run.
6655 There is also a new remote serial stub for SPARC processors. You can
6656 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6657 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6658 processor with a serial port.
6662 Configure.in files have become much easier to read and modify. A new
6663 `table driven' format makes it more obvious what configurations are
6664 supported, and what files each one uses.
6668 There is a new opcodes library which will eventually contain all of the
6669 disassembly routines and opcode tables. At present, it only contains
6670 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6671 disassembler (binutils/objdump) to share these routines.
6673 The libiberty library is now copylefted under the GNU Library General
6674 Public License. This allows more liberal use, and was done so libg++
6675 can use it. This makes no difference to GDB, since the Library License
6676 grants all the rights from the General Public License.
6680 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6681 reference to the stabs symbol info used by the debugger. It is (as far
6682 as we know) the only published document on this fascinating topic. We
6683 encourage you to read it, compare it to the stabs information on your
6684 system, and send improvements on the document in general (to
6685 bug-gdb@prep.ai.mit.edu).
6687 And, of course, many bugs have been fixed.
6690 *** Changes in GDB-4.6:
6692 * Better support for C++ function names
6694 GDB now accepts as input the "demangled form" of C++ overloaded function
6695 names and member function names, and can do command completion on such names
6696 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6697 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6698 Make use of command completion, it is your friend.
6700 GDB also now accepts a variety of C++ mangled symbol formats. They are
6701 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6702 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6703 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6704 for the list of formats.
6706 * G++ symbol mangling problem
6708 Recent versions of gcc have a bug in how they emit debugging information for
6709 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6710 directory) can be applied to gcc to fix the problem. Alternatively, if you
6711 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6712 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6713 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6716 * New 'maintenance' command
6718 All of the commands related to hacking GDB internals have been moved out of
6719 the main command set, and now live behind the 'maintenance' command. This
6720 can also be abbreviated as 'mt'. The following changes were made:
6722 dump-me -> maintenance dump-me
6723 info all-breakpoints -> maintenance info breakpoints
6724 printmsyms -> maintenance print msyms
6725 printobjfiles -> maintenance print objfiles
6726 printpsyms -> maintenance print psymbols
6727 printsyms -> maintenance print symbols
6729 The following commands are new:
6731 maintenance demangle Call internal GDB demangler routine to
6732 demangle a C++ link name and prints the result.
6733 maintenance print type Print a type chain for a given symbol
6735 * Change to .gdbinit file processing
6737 We now read the $HOME/.gdbinit file before processing the argv arguments
6738 (e.g. reading symbol files or core files). This allows global parameters to
6739 be set, which will apply during the symbol reading. The ./.gdbinit is still
6740 read after argv processing.
6742 * New hosts supported
6744 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6746 GNU/Linux support i386-unknown-linux or linux
6748 We are also including code to support the HP/PA running BSD and HPUX. This
6749 is almost guaranteed not to work, as we didn't have time to test or build it
6750 for this release. We are including it so that the more adventurous (or
6751 masochistic) of you can play with it. We also had major problems with the
6752 fact that the compiler that we got from HP doesn't support the -g option.
6755 * New targets supported
6757 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6759 * More smarts about finding #include files
6761 GDB now remembers the compilation directory for all include files, and for
6762 all files from which C is generated (like yacc and lex sources). This
6763 greatly improves GDB's ability to find yacc/lex sources, and include files,
6764 especially if you are debugging your program from a directory different from
6765 the one that contains your sources.
6767 We also fixed a bug which caused difficulty with listing and setting
6768 breakpoints in include files which contain C code. (In the past, you had to
6769 try twice in order to list an include file that you hadn't looked at before.)
6771 * Interesting infernals change
6773 GDB now deals with arbitrary numbers of sections, where the symbols for each
6774 section must be relocated relative to that section's landing place in the
6775 target's address space. This work was needed to support ELF with embedded
6776 stabs used by Solaris-2.0.
6778 * Bug fixes (of course!)
6780 There have been loads of fixes for the following things:
6781 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6782 i960, stabs, DOS(GO32), procfs, etc...
6784 See the ChangeLog for details.
6786 *** Changes in GDB-4.5:
6788 * New machines supported (host and target)
6790 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6792 SGI Irix-4.x mips-sgi-irix4 or iris4
6794 * New malloc package
6796 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6797 Mmalloc is capable of handling mutiple heaps of memory. It is also
6798 capable of saving a heap to a file, and then mapping it back in later.
6799 This can be used to greatly speedup the startup of GDB by using a
6800 pre-parsed symbol table which lives in a mmalloc managed heap. For
6801 more details, please read mmalloc/mmalloc.texi.
6805 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6806 'help info proc' for details.
6808 * MIPS ecoff symbol table format
6810 The code that reads MIPS symbol table format is now supported on all hosts.
6811 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6814 * File name changes for MS-DOS
6816 Many files in the config directories have been renamed to make it easier to
6817 support GDB on MS-DOSe systems (which have very restrictive file name
6818 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6819 environment) is close to working but has some remaining problems. Note
6820 that debugging of DOS programs is not supported, due to limitations
6821 in the ``operating system'', but it can be used to host cross-debugging.
6823 * Cross byte order fixes
6825 Many fixes have been made to support cross debugging of Sparc and MIPS
6826 targets from hosts whose byte order differs.
6828 * New -mapped and -readnow options
6830 If memory-mapped files are available on your system through the 'mmap'
6831 system call, you can use the -mapped option on the `file' or
6832 `symbol-file' commands to cause GDB to write the symbols from your
6833 program into a reusable file. If the program you are debugging is
6834 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6835 Future GDB debugging sessions will notice the presence of this file,
6836 and will quickly map in symbol information from it, rather than reading
6837 the symbol table from the executable program. Using the '-mapped'
6838 option in a GDB `file' or `symbol-file' command has the same effect as
6839 starting GDB with the '-mapped' command-line option.
6841 You can cause GDB to read the entire symbol table immediately by using
6842 the '-readnow' option with any of the commands that load symbol table
6843 information (or on the GDB command line). This makes the command
6844 slower, but makes future operations faster.
6846 The -mapped and -readnow options are typically combined in order to
6847 build a `fred.syms' file that contains complete symbol information.
6848 A simple GDB invocation to do nothing but build a `.syms' file for future
6851 gdb -batch -nx -mapped -readnow programname
6853 The `.syms' file is specific to the host machine on which GDB is run.
6854 It holds an exact image of GDB's internal symbol table. It cannot be
6855 shared across multiple host platforms.
6857 * longjmp() handling
6859 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6860 siglongjmp() without losing control. This feature has not yet been ported to
6861 all systems. It currently works on many 386 platforms, all MIPS-based
6862 platforms (SGI, DECstation, etc), and Sun3/4.
6866 Preliminary work has been put in to support the new Solaris OS from Sun. At
6867 this time, it can control and debug processes, but it is not capable of
6872 As always, many many bug fixes. The major areas were with g++, and mipsread.
6873 People using the MIPS-based platforms should experience fewer mysterious
6874 crashes and trashed symbol tables.
6876 *** Changes in GDB-4.4:
6878 * New machines supported (host and target)
6880 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6882 BSD Reno on Vax vax-dec-bsd
6883 Ultrix on Vax vax-dec-ultrix
6885 * New machines supported (target)
6887 AMD 29000 embedded, using EBMON a29k-none-none
6891 GDB continues to improve its handling of C++. `References' work better.
6892 The demangler has also been improved, and now deals with symbols mangled as
6893 per the Annotated C++ Reference Guide.
6895 GDB also now handles `stabs' symbol information embedded in MIPS
6896 `ecoff' symbol tables. Since the ecoff format was not easily
6897 extensible to handle new languages such as C++, this appeared to be a
6898 good way to put C++ debugging info into MIPS binaries. This option
6899 will be supported in the GNU C compiler, version 2, when it is
6902 * New features for SVR4
6904 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6905 shared libraries. Debugging dynamically linked programs should present
6906 only minor differences from debugging statically linked programs.
6908 The `info proc' command will print out information about any process
6909 on an SVR4 system (including the one you are debugging). At the moment,
6910 it prints the address mappings of the process.
6912 If you bring up GDB on another SVR4 system, please send mail to
6913 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6915 * Better dynamic linking support in SunOS
6917 Reading symbols from shared libraries which contain debugging symbols
6918 now works properly. However, there remain issues such as automatic
6919 skipping of `transfer vector' code during function calls, which
6920 make it harder to debug code in a shared library, than to debug the
6921 same code linked statically.
6925 GDB is now using the latest `getopt' routines from the FSF. This
6926 version accepts the -- prefix for options with long names. GDB will
6927 continue to accept the old forms (-option and +option) as well.
6928 Various single letter abbreviations for options have been explicity
6929 added to the option table so that they won't get overshadowed in the
6930 future by other options that begin with the same letter.
6934 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6935 Many assorted bugs have been handled. Many more remain to be handled.
6936 See the various ChangeLog files (primarily in gdb and bfd) for details.
6939 *** Changes in GDB-4.3:
6941 * New machines supported (host and target)
6943 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6944 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6945 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6947 * Almost SCO Unix support
6949 We had hoped to support:
6950 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6951 (except for core file support), but we discovered very late in the release
6952 that it has problems with process groups that render gdb unusable. Sorry
6953 about that. I encourage people to fix it and post the fixes.
6955 * Preliminary ELF and DWARF support
6957 GDB can read ELF object files on System V Release 4, and can handle
6958 debugging records for C, in DWARF format, in ELF files. This support
6959 is preliminary. If you bring up GDB on another SVR4 system, please
6960 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6965 GDB now uses the latest `readline' library. One user-visible change
6966 is that two tabs will list possible command completions, which previously
6967 required typing M-? (meta-question mark, or ESC ?).
6971 The `stepi' bug that many of you noticed has been squashed.
6972 Many bugs in C++ have been handled. Many more remain to be handled.
6973 See the various ChangeLog files (primarily in gdb and bfd) for details.
6975 * State of the MIPS world (in case you wondered):
6977 GDB can understand the symbol tables emitted by the compilers
6978 supplied by most vendors of MIPS-based machines, including DEC. These
6979 symbol tables are in a format that essentially nobody else uses.
6981 Some versions of gcc come with an assembler post-processor called
6982 mips-tfile. This program is required if you want to do source-level
6983 debugging of gcc-compiled programs. I believe FSF does not ship
6984 mips-tfile with gcc version 1, but it will eventually come with gcc
6987 Debugging of g++ output remains a problem. g++ version 1.xx does not
6988 really support it at all. (If you're lucky, you should be able to get
6989 line numbers and stack traces to work, but no parameters or local
6990 variables.) With some work it should be possible to improve the
6993 When gcc version 2 is released, you will have somewhat better luck.
6994 However, even then you will get confusing results for inheritance and
6997 We will eventually provide full debugging of g++ output on
6998 DECstations. This will probably involve some kind of stabs-in-ecoff
6999 encapulation, but the details have not been worked out yet.
7002 *** Changes in GDB-4.2:
7004 * Improved configuration
7006 Only one copy of `configure' exists now, and it is not self-modifying.
7007 Porting BFD is simpler.
7011 The `step' and `next' commands now only stop at the first instruction
7012 of a source line. This prevents the multiple stops that used to occur
7013 in switch statements, for-loops, etc. `Step' continues to stop if a
7014 function that has debugging information is called within the line.
7018 Lots of small bugs fixed. More remain.
7020 * New host supported (not target)
7022 Intel 386 PC clone running Mach i386-none-mach
7025 *** Changes in GDB-4.1:
7027 * Multiple source language support
7029 GDB now has internal scaffolding to handle several source languages.
7030 It determines the type of each source file from its filename extension,
7031 and will switch expression parsing and number formatting to match the
7032 language of the function in the currently selected stack frame.
7033 You can also specifically set the language to be used, with
7034 `set language c' or `set language modula-2'.
7038 GDB now has preliminary support for the GNU Modula-2 compiler,
7039 currently under development at the State University of New York at
7040 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7041 continue through the fall of 1991 and into 1992.
7043 Other Modula-2 compilers are currently not supported, and attempting to
7044 debug programs compiled with them will likely result in an error as the
7045 symbol table is read. Feel free to work on it, though!
7047 There are hooks in GDB for strict type checking and range checking,
7048 in the `Modula-2 philosophy', but they do not currently work.
7052 GDB can now write to executable and core files (e.g. patch
7053 a variable's value). You must turn this switch on, specify
7054 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7055 by assigning a new value to a variable. Modifications take
7058 * Automatic SunOS shared library reading
7060 When you run your program, GDB automatically determines where its
7061 shared libraries (if any) have been loaded, and reads their symbols.
7062 The `share' command is no longer needed. This also works when
7063 examining core files.
7067 You can specify the number of lines that the `list' command shows.
7070 * New machines supported (host and target)
7072 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7073 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7074 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7076 * New hosts supported (not targets)
7078 IBM RT/PC: romp-ibm-aix or rtpc
7080 * New targets supported (not hosts)
7082 AMD 29000 embedded with COFF a29k-none-coff
7083 AMD 29000 embedded with a.out a29k-none-aout
7084 Ultracomputer remote kernel debug a29k-nyu-kern
7086 * New remote interfaces
7092 *** Changes in GDB-4.0:
7096 Wide output is wrapped at good places to make the output more readable.
7098 Gdb now supports cross-debugging from a host machine of one type to a
7099 target machine of another type. Communication with the target system
7100 is over serial lines. The ``target'' command handles connecting to the
7101 remote system; the ``load'' command will download a program into the
7102 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7103 also supports debugging of realtime processes running under VxWorks,
7104 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7105 stub on the target system.
7107 New CPUs supported include the AMD 29000 and Intel 960.
7109 GDB now reads object files and symbol tables via a ``binary file''
7110 library, which allows a single copy of GDB to debug programs of multiple
7111 object file types such as a.out and coff.
7113 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7114 refcard.dvi and refcard.ps are available to format it).
7117 * Control-Variable user interface simplified
7119 All variables that control the operation of the debugger can be set
7120 by the ``set'' command, and displayed by the ``show'' command.
7122 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7123 ``Show prompt'' produces the response:
7124 Gdb's prompt is new-gdb=>.
7126 What follows are the NEW set commands. The command ``help set'' will
7127 print a complete list of old and new set commands. ``help set FOO''
7128 will give a longer description of the variable FOO. ``show'' will show
7129 all of the variable descriptions and their current settings.
7131 confirm on/off: Enables warning questions for operations that are
7132 hard to recover from, e.g. rerunning the program while
7133 it is already running. Default is ON.
7135 editing on/off: Enables EMACS style command line editing
7136 of input. Previous lines can be recalled with
7137 control-P, the current line can be edited with control-B,
7138 you can search for commands with control-R, etc.
7141 history filename NAME: NAME is where the gdb command history
7142 will be stored. The default is .gdb_history,
7143 or the value of the environment variable
7146 history size N: The size, in commands, of the command history. The
7147 default is 256, or the value of the environment variable
7150 history save on/off: If this value is set to ON, the history file will
7151 be saved after exiting gdb. If set to OFF, the
7152 file will not be saved. The default is OFF.
7154 history expansion on/off: If this value is set to ON, then csh-like
7155 history expansion will be performed on
7156 command line input. The default is OFF.
7158 radix N: Sets the default radix for input and output. It can be set
7159 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7160 in the current radix, so "set radix 10" is always a no-op.
7162 height N: This integer value is the number of lines on a page. Default
7163 is 24, the current `stty rows'' setting, or the ``li#''
7164 setting from the termcap entry matching the environment
7167 width N: This integer value is the number of characters on a line.
7168 Default is 80, the current `stty cols'' setting, or the ``co#''
7169 setting from the termcap entry matching the environment
7172 Note: ``set screensize'' is obsolete. Use ``set height'' and
7173 ``set width'' instead.
7175 print address on/off: Print memory addresses in various command displays,
7176 such as stack traces and structure values. Gdb looks
7177 more ``symbolic'' if you turn this off; it looks more
7178 ``machine level'' with it on. Default is ON.
7180 print array on/off: Prettyprint arrays. New convenient format! Default
7183 print demangle on/off: Print C++ symbols in "source" form if on,
7186 print asm-demangle on/off: Same, for assembler level printouts
7189 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7192 * Support for Epoch Environment.
7194 The epoch environment is a version of Emacs v18 with windowing. One
7195 new command, ``inspect'', is identical to ``print'', except that if you
7196 are running in the epoch environment, the value is printed in its own
7200 * Support for Shared Libraries
7202 GDB can now debug programs and core files that use SunOS shared libraries.
7203 Symbols from a shared library cannot be referenced
7204 before the shared library has been linked with the program (this
7205 happens after you type ``run'' and before the function main() is entered).
7206 At any time after this linking (including when examining core files
7207 from dynamically linked programs), gdb reads the symbols from each
7208 shared library when you type the ``sharedlibrary'' command.
7209 It can be abbreviated ``share''.
7211 sharedlibrary REGEXP: Load shared object library symbols for files
7212 matching a unix regular expression. No argument
7213 indicates to load symbols for all shared libraries.
7215 info sharedlibrary: Status of loaded shared libraries.
7220 A watchpoint stops execution of a program whenever the value of an
7221 expression changes. Checking for this slows down execution
7222 tremendously whenever you are in the scope of the expression, but is
7223 quite useful for catching tough ``bit-spreader'' or pointer misuse
7224 problems. Some machines such as the 386 have hardware for doing this
7225 more quickly, and future versions of gdb will use this hardware.
7227 watch EXP: Set a watchpoint (breakpoint) for an expression.
7229 info watchpoints: Information about your watchpoints.
7231 delete N: Deletes watchpoint number N (same as breakpoints).
7232 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7233 enable N: Re-enables watchpoint number N (same as breakpoints).
7236 * C++ multiple inheritance
7238 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7241 * C++ exception handling
7243 Gdb now supports limited C++ exception handling. Besides the existing
7244 ability to breakpoint on an exception handler, gdb can breakpoint on
7245 the raising of an exception (before the stack is peeled back to the
7248 catch FOO: If there is a FOO exception handler in the dynamic scope,
7249 set a breakpoint to catch exceptions which may be raised there.
7250 Multiple exceptions (``catch foo bar baz'') may be caught.
7252 info catch: Lists all exceptions which may be caught in the
7253 current stack frame.
7256 * Minor command changes
7258 The command ``call func (arg, arg, ...)'' now acts like the print
7259 command, except it does not print or save a value if the function's result
7260 is void. This is similar to dbx usage.
7262 The ``up'' and ``down'' commands now always print the frame they end up
7263 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7264 frames without printing.
7266 * New directory command
7268 'dir' now adds directories to the FRONT of the source search path.
7269 The path starts off empty. Source files that contain debug information
7270 about the directory in which they were compiled can be found even
7271 with an empty path; Sun CC and GCC include this information. If GDB can't
7272 find your source file in the current directory, type "dir .".
7274 * Configuring GDB for compilation
7276 For normal use, type ``./configure host''. See README or gdb.texinfo
7279 GDB now handles cross debugging. If you are remotely debugging between
7280 two different machines, type ``./configure host -target=targ''.
7281 Host is the machine where GDB will run; targ is the machine
7282 where the program that you are debugging will run.